geoinformatics 2006 vol04

Open Source Software Enters UMN MapServer and gvSIG Most Potential OnesOpen Source Software Enters

IntroductionToday, GIS software can be used for varioustasks of spatial data and is essential in manybranches. The scope of this software haschanged from cartography to many otherareas: not only administration and engineeroffices but also wholesalers or hospitals canbenefit from the combination of analysingtools and geographic information. About 90%of the available geographic data are estimatedto be georeferenceable. This means that everyselectable point on a map is provided withcoordinates. To control this bulk of raw data,potent tools are necessary. These tools haveto make data, that are usually stored in spatialdatabases, available.Depending on the needs of the user, currently

two kinds of GIS software fulfil the mainrequirements: the light web client or the heavyclient, also called Desktop GIS. While the firstone only offers basic tools, the heavy clientoffers many other possibilities and can also beadapted to the various user profiles likeurbanism, environmental science, and market-ing.In the last years, Open Source Software hasbeen getting very popular. Numerous softwareareas already offer an equivalent option toproprietary products. But until now, the marketsegment of GIS and CAD software didn’t pro-vide serious alternatives to the expensive andsometimes oversized market-leading softwarepackages. Due to this lack of selection, themain part of the fast growing community of

GIS users has been bound to use certain soft-ware. So, the selection of a GIS normally wasneither a well-considered decision nor theresult of an analysis of the existing possibili-ties. This unsatisfactory situation is nowchanging because of the rising of several verypromising Open Source projects, such asMapServer or gvSIG.

Actual SituationUntil now, the market of software that is dedicated to modify and treat spatial informa-tion and cartography has been monopolizedby a few proprietary products. This phe-nomenon was noticeable in different forms, indesktop GIS as well as in web clients or alsomap servers.As a reason of the missing competition, sever-al competitive alternatives have come intobeing all over the world in the last few years.Some of these alternatives are now developinginto serious projects, supported by universi-ties, public administrations and private enter-prises. The best examples are the projectMapServer of the University of Minnesota andgvSIG, a Desktop GIS, developed by theValencian Government and the private compa-ny IVER.As aforementioned, the situation in many GISevaluation processes is that not the most suit-able product is selected but the most habitualone. The product is chosen without evaluatingthe alternatives. Normally, the software userisn’t aware of his requirements and functionshe needs. Although users often only need cer-tain basic functions, they are constrained tobuy expensive software with many complex,but unnecessary tools.The logical decision shouldn’t be buying themost common software, but buying the soft-ware that fulfils the user’s requirements best.

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Geographic Information Systems (GIS) are getting more and more important in the business world. Besides the proprietary products,

now also several Open Source projects are getting a competitive alternative for the versatile use of GIS. gvSIG is an excellent

example of a future GIS alternative and will include precise CAD tools. The Java based software is subject to the most important

international standards (OGC) and the new paradigms of the Spatial Data Infrastructure (SDI).

By Alvaro Anguix Alfaro and Andreas Wehrle

Map of Europe, created with gvSIG.

Prod_GEO_4_2006 29-05-2006 15:06 Pagina 6

One can think of language, comfort, price,comprehensibility, and compatibility, to men-tion a few.

Open Source GIS ProjectsBefore, Open Source software often was dis-liked. The preconceived opinion was that aproduct free of charge can’t be worth as muchas one with charge. In certain cases, this opinion was correct, since many Open Sourceprojects weren’t developed well enough. Butwith the success of several Open Source projects, public interest is awakened. The benefits from Open Source software are:• Independence and control over the final

product;• Investment in variety: all investment can

be spent in development instead of royalties;

• Maximizing the client’s rights.

In the area of GIS, various projects are worthpaying attention to because of their maturityand several fulfilled conditions. The followingtools are able to substitute the well-knownproprietary software. The conditions are:• Potency and functionality the software

offers;• Projects with a constant development and

support by an administration or companythat is able to guarantee the future of theproject;

• Multiple platform tools that work underWindows as well as under Linux;

• Tools that incorporate the latest trends inrelation to geographic information, SpatialData Infrastructure (SDI) or INfrastructurefor SPatial InfoRmation in Europe(INSPIRE);

• Software that observes standards, like theOpen Geospatial Consortium (OGC).

Desktop GIS: gvSIGDesktop GIS are the most potent tools for thetreatment of geographic information. Theyinclude numerous functions that allowanalysing spatial data, cartographic editionand map design. Actually, there are severalproducts (GRASS, JUMP, QGIS, SAGA GIS) on

the market that are to be

Map Server: UMN MapServerThe map server software is the base tool thatpermits the distribution and diffusion of geo-graphic information via the Internet. At themoment, the leader in the Open Source seg-ment is UMN MapServer. Other leading prod-ucts that are quite interesting are GeoServer orDegree.UMN MapServer is commonly accepted by themarket. Originally, it was created by theUniversity of Minnesota in cooperation withNASA and the university’s department ofNatural Resources. The aim was to make mapsavailable on the Internet. It is created withseveral Open Source and Freeware libraries,such as Shapelib, FreeType, Proj.4, libTIFF, andPerl, and may be installed like a CommonGateway Interface (CGI) or a module on a webserver (in the case of Apache).For the control of map services several visualtools exist, from which MapLab is the mostdistinguished one. It is also available as OpenSource and functions with PHP. It is integratedinto the following products:

taken seriously, of which gvSIG is the mostprogressive one.gvSIG counts on the participation of theValencian Government, the company IVER andthe university Jaume I of Castellón. It is a Javadevelopment and operates under the GPLlicence. Thanks to its Java-platform characteris-tics, it doesn’t depend on the operating sys-tem. It works under Windows as well as Linux,the last one spreading rapidly. The multi-lan-guage gvSIG is conceived as a heavy GISclient that permits the analysis and consulta-tion of spatial information, cartographic editionand generating maps.The frequent spatial data standard formatsthat are used on other GIS systems are sup-ported by gvSIG. Example of formats areshapefile, DXF, DGN, ecw, and MrSID. gvSIGfollows the standards of the Open GeospatialConsortium. This means it is able to read localdata as well as remote data (as WMS, WFSand WCS). At the moment, a catalogue is being devel-oped that permits the search and discovery ofspatial data, as well as an automatic metadatagenerator. Metadata is information about data;in the case of cartography, it could be thescale, the year of publication or the source ofthe map. gvSIG is quite a young project, atthe moment of this publication, it is in the ver-sion 0.5. It isn’t just an alternative to the actual solution, it is also an innovative productthat fixes new limits as it is the first desktopGIS that implements the possibility to utiliseWMS, WFS and WCS. Parallel to the GIS development, gvSIG isentering into a second area: the implementa-tion of advanced CAD tools. In this case, CADtools are needed for the cartographic editionof a map. The use of precise CAD tools isinevitable for the cartographic edition, buttheir precision must be higher than the one ofthe habitual integrated tools we know fromother GIS software. With the foreseen develop-ments of gvSIG, the use of additional CADsoftware won’t be necessary any longer.Another advantage of the Open Source charac-teristic of gvSIG is the huge community in theworld of Internet. Thanks to their activity, it ispossible to get support and additional fea-tures, in English as well as in other languages.

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s GIS Markets GIS Market

Logo gvSIG.

Important AbbreviationsGPL: GNU General Public License. Thislicense grants the recipients several rightsfor Open Source software, such as the freeuse, improvement or redistribution of theprogram.BSD: Berkeley Software Distribution. It is asimilar license like GPL.RDBMS: Relational Database ManagementSystem. Particular kind to store the data,strongly related with SQL.SQL: Structured Query Language.Computer language that is used to getdata from a data base and to modify thedata in the data base.OGC: Open Geospatial Consortium.International Organisation in which partici-pate private companies as well as publicorganisations, with the aim to create stan-dards in the world of geospatial content.WMS: Web Map Service. Is able to visu-alise maps dynamically from geographicdata.WFS: Web Feature Service. Interface thatenables the request and online modifica-tion of geospatial vector data.WCS: Web Coverage Service. Interface thatenables the request and online modifica-tion of geospatial raster data.

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• MapEdit: permits the creation and editionof map services, defining layers, symbology, and so on;

• MapBrowser: helps to select several GISdata sources from various locations;

• GMFactory: this tool helps to create clientsto access map services. It allows selectingthe type of client (Java, HTML), availablefunctions and design aspects.

Spatial Database: PostGISPostgreSQL is a free database, created underthe licence BSD. In the area of database sys-tems, there are many other successful OpenSource projects, like MySQL, Firebird, andMaxDB.PostGIS is an extension to the object-orienteddatabase system PostgreSQL and works underthe licence GPL. It allows the use of GISobjects and other objects that appear in theOGC specifications. One can think of thingslike points, lines, polygons, multilines, multi-points and geometric collections. It works withGeometry Engine Open Source (GEOS) as drivefor the topologic control.PostGIS, and generally any spatial extension toa RDBMS, allows a high flexibility, as it is pos-sible to realize spatial operations at the sourceof the data. PostGIS is an extension forPostgreSQL and defines new types of data,creates two tables with relevant information tothe system (data projection and a column thatcontains the geographic information).Furthermore, it possesses interfaces for thedata exchange with MapServer.

SDI and INSPIREThe world of geo-graphic informationhas changed quickly,partly because of theintroduction of certainconcepts and method-ologies about SpatialData Infrastructures(SDIs). This movementis gaining more andmore influence and isadopted by variouspublic administrations.An SDI is a mecha-nism that unites andstandardises spatialinformation in andbetween organisations.It is like a distributedGIS which shares infor-mation within a work-ing group.The history of theSpatial DataInfrastructure started inthe year 1994, when

the then North American president, William J.Clinton, published a presidential order todevelop the National Infrastructure of SpatialData for the U.S.A (NSDI). The main ideabehind this: ‘sharing knowledge is a source ofeconomical growing’.In the year 2004, the European Commissionalso decided to create a Spatial DataInfrastructure inside the European Community,called INSPIRE. The European SDI was com-posed like a puzzle, created by several partsof national and local SDIs. For already twoyears now, the influence of INSPIRE and thenecessity to fulfil the Commissions’ decisionhave brought to light several SDIs at various

levels. The aim is to maximize access to spa-tial data and minimize the redundancy ofinvestments.To construct an SDI, some duties must be car-ried out. It is inevitable to possess the meta-data of geographic information. As softwareelements, the following parts are necessary:• Web Map Server: distributes geographic

information. As an Open Source solution,UMN MapServer could be used;

• Catalogue: helps to search and localize thegeographic data;

• SDI client: desktop GIS client. The onlyone that is capable is gvSIG, in OpenSource as well as in proprietary software.

Alvaro Anguix Alfaro ([email protected]) and

Andreas Wehrle ([email protected]) are

respectively Head of the Open Source department

and GIS Specialist for Iver Information Technologies,

a Spanish GIS applications developer.

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Map server of the tourist agency of the Valencian Community, developed with UMNMapServer.

Map of Andalusia, Spain, created with gvSIG.

gvSIG: www.gvsig.gva.esUMN MapServer:http://mapserver.gis.umn.eduPostGIS: http://postgis.refractions.netINSPIRE: www.ec-gis.org/inspireOpen Geospatial Consortium: www.opengeospatial.org

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GIS Contributes to the Constitution of IraqUrgent Need for Information on Available Water Resources

GIS Contributes to the Constitution of Iraq

The Otoman Empire collapsed in the first decades of the twentieth century, leaving

behind a hunting ground in the Middle East for the remaining imperialists. In their

struggle for control the competing superpowers redrew the map several times with

very little consideration of ethnic borders and natural units.

By Zoltán Vekerdy

Rainfall and SnowmeltThe dry climate makes control over water tobe of primary importance for the survival ofthe population. The vast lowlands are desertsand almost all the water is brought to thepeople by the rivers collecting runoff from rain-fall and snow melt in the mountains.Abundance of river water made the earlyemergence of civilizations in the Tigris-Euphrates valley possible, and mainained vastwetlands throughout history in one of thedryest climates of the Earth.It is understandable that for Iraq, the down-stream country of the region, proper legislationover water rights is a cornerstone to peacefuldevelopment. A large part of the populationlives in regions with very scarce waterresources, so control of this commodityreceived careful attention during the formula-tion of the most significant law of Iraq: theconstitution. Information on availableresources in and around the country was

needed to ensure the correct wording in thedocument.

Quick AssessmentThe United Nations approached the depart-ment of Water Resources of the InternationalInstitute for Geo-Information Science and EarthObservation (ITC), the Netherlands, requestingfor a quick assessment of the situation, as thenegotiating partners had asked for this infor-mation in the course of drafting the law. Thismeant an unbiased and consistent responsewas needed almost immediately.Publicly available information on the WorldWide Web and geo-information technologywere the basic tools applied in this mini-pro-ject. Information on global water resources canbe found on the website of the Water SystemsAnalysis Group of the Complex SystemsResearch Center of the University of NewHampshire. This data set is based on the com-bination of measured river discharges and con-

tinental scale runoff modelling. The underlyingtechnology makes it possible to preserve theaccuracy of the in-situ discharge measure-ments as well as the spatial and temporal dis-tribution of simulated runoff. Thereby it pro-vides the ‘best estimate’ of terrestrial runoffover large domains. The calculations are basedon a global 30-minute grid (Fekete et al.2000).

Small DatabaseITC hydrologists used the Integrated Land andWater Information System (ILWIS) - softwaredeveloped by the Institute itself - for analysingthe data and calculating the spatial distribu-tion of the water resources in Iraq and theneighbouring countries. The overlays, seeimage, were merged into a small database.The results were sent, both in quantitativemap, and tabular forms to the United Nationswithin just a few hours of the initial request,enabling negotiations to proceed without inter-ruption. A constitution never contains technical details.The result map and the table formed the basisof formulating the sections about the need forfair distribution of water resources. Withoutthis technical information, the negotiatorswould not had a clear view about the issue ofwater in the region. Without GIS technology, itwould not have been possible to provide therequested information within a few hours. Theconstitution of Iraq was accepted on 15October 2005 (Wikipedia 2005).

ReferencesFekete, B., C. J. Vörösmarty and W. Grabs(2000). Global, composite runoff fields basedon observed river discharge and simulatedwater balances. New Hampshire, USA, WaterSystems Analysis Group, Complex SystemsResearch Center (CSRC), University of NewHampshire: 115.

Zoltán Vekerdy ([email protected]) is an Assistant

Professor at ITC, Department of Water Resources.

More information via www.itc.nl,

www.grdc.sr.unh.edu/ and

http://en.wikipedia.org/wiki/Iraqi_Constitution.

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Calculation units overlaid with the basic grid ofthe composite runoff fields. Sources: (Fekete etal. 2000) and UN.

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Shifting Mindsets in an EvolvinImpediment by Transformation ProcessesShifting Mindsets in an Evolvin

People in a society are generally unaware of the impact of slowly evolving changes

over a long period of time. Evolution, in contrast to revolution, does not tend to create

historical milestones. However, our living space, together with spatial and social

environments, is changing significantly.

Gerhard Muggenhuber and Rob Mahoney

Paper MapsThere is an enormous reduction in landresources occurring every year, reducing theavailability of rural agricultural land. Similarlythe paradigm shift of providing spatial infor-mation online as opposed to paper maps ischanging society’s mindsets almost beyondrecognition compared to just a few yearsago. The processes that underpin our socialinteractions have changed beyond all recog-nition in recent years enabling us to use theinterrelated parameters of location, spaceand time. This, together with technologicalinnovation, has supported the creation of amobile society that requires rapid access toa variety of information and supporting pro-cesses. This is just the beginning of themajor changes that will confront us in thefuture. Society will think spatially withoutrealising it. This will be the ultimate shiftingof the human mindset.

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FIG-Vice president Stig Enemark with FIG chairs and incomming chairs of FIG-commissions 2, 3 and 7 on the occasion of the FIG Workshop on e-Governance, KnowledgeManagement and e-Learning, Budapest April 2006.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 10

Four AreasIn the field of spatial information managementthe changes that are occurring can best beobserved by considering four inter-relatedareas: geo-tools, geo-data, processes, andhuman interactions.

Geo-toolsIn the past only experts had the educationand training to use complex geo-tools and

sophisticated society, create a potential weak-ness for such systems.

Processes One of the major challenges facing the emerg-ing spatial society is how to improve the processes associated with the wide use andavailability of spatial information. In the pastthe general public was not particularly interest-ed in technical issues with the consequencethat decision-making was often regarded asbeing clouded in mystery. However, within thelast decade individuals have been able toexperience the benefits to be gained fromimproved processes such as new public man-agement and e-government initiatives. Thesepublic sector reforms have focused publicadministration’s attention on the citizens’interests, promoting the need for comparableservices within the public and private sectors.Among the initiatives being devised toimprove transparency, copyright and costissues is EU-INSPIRE.Modern governance requires transparency andthe involvement of communities and citizensin the decision-making process. This alsoapplies to community-based land managementprocesses and development administration ingeneral. Modern spatial information manage-ment tools facilitate decentralisation, commu-nity empowerment, and citizen participation,which guarantee social cohesion and a senseof belonging.Visualisation of spatial information can, andwill increasingly, be used to optimise the sus-tainable resources within a given framework.We have to be aware that some societies withvarious and diverse value systems are natural-ly under higher social pressure and thisrequires even more focus on transparent processes.

Human InteractionsA key issue is how we can introduce theimproved use of geo-tools, spatial data andprocesses. Successful organisations tend toencourage employees to adopt commonvalue systems which ensure that the activi-ties of individuals are in line with the mission and vision of the organisation.

large organisations were required to financethe introduction of the technology. Todaythese tools have become pervasive and arewidely used by the general public, often with-out them being aware of it. Handheld devices,similar to conventional mobile phones (andnow becoming incorporated into mobilephones), have become capable of providingknowledge of the user’s current geographicposition. These tools, and the services theyprovide, require improved access to relevantdatabases. The geo-industry is now movingahead rapidly to provide the appropriate geo-tools to support the growing availabilityof geospatial information. One of the largestexhibitions in Europe designed to displaystate-of-the-art geo-tools will take place at theFIG-conference in Munich in October 2006.

Geo-data More and more geo-data has become avail-able in the public arena in recent years. Withinthe last decade significant volumes of geo-data have been digitised creating valuabledata sources. The impact of this data availa-bility has made significant inroads into socialinteraction both at the individual and organisa-tional level. The industry is currently workinghard to harmonise a number of related refer-ence systems that will ensure the interoper-ability user friendly data. Users will be able tocombine information gathered in the field withpositional information derived from GNSS-services (GPS, Galileo) and others. Today, weare already able to address some of the majoruser complaints by combining data associatedwith different reference frames and differentdatabases. One of the challenges to be addressed in thenear future will be the transition from ‘normalheights’ to ‘orthometric heights’ where the userwill find it complex to understand that physicalobservations of the same water level, doesnot mean same height. This type of examplewill require major marketing activities toensure that the users really understand thecomplexity of the datasets involved. Withoutthis awareness of the issues surrounding theuse of some datasets, misinterpreted datacould, during a period of transition to a more


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g Societyg Society

The International Federationof Surveyors (FIG) supportsthe current transformationprocess by providing a platform for networking,

transfer of knowledge and sharing of innovative ideas amongst professional surveyors world wide.

FIG, through its ten commissions, focuseson specific topics within the surveying profession. Examples of the commissionswork are provided in documents down-loadable, from on the FIG websitewww.fig.net. These include:• Mutual Recognition of Professional

Qualifications;• FIG Surveying Education Database;• Hydrography in Ports and Harbours;• Contributions to sustainable develop-

ment: Urban-Rural Interrelationship forSustainable DevelopmentBest Practice Guidelines in City-wide LandInformation Management Spatial Information for SustainableDevelopmentLand Administration for SustainableDevelopment

FIG cooperates closely with a number oforganisations including:• United Nations Office for Outer Space

on multiple and integrated satellite sys-tems (GPS, GLONASS, GALILEO);

• Habitat Professionals Forum;• The Joint Board of Geospatial

Information Societies;• International Federation of Hydrographic

Societies;• UNB on Marine Cadastre;• United Nations Working Party on Land

Administration.

Society will think spatially without realising it. This will be the

ultimate shifting of the human mindset.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 11

This approach also applies to societies wheregovernment initiatives, such as the educationalsystem in Finland, are designed to providelong-term success in this area – a seriousinvestment in creating a shifting mindset.The approach of customers to processes andservices based on spatial information, howev-er, cannot be influenced and training can bedifficult to achieve. This is in spite of the factthat this is rapidly changing and there areexamples of technical innovations being intro-duced within the last decade without anytraining at all. A good example of this is themobile telephone, a complex technologicaldevice sold and used with minimal or no train-ing. Similarly services like access to spatialinformation provided by ‘Google Earth’ do notrequire any knowledge of GIS. This trend tends to suggest that technology isno longer the challenge, nor is it impeding thetake-up of these systems. The real challenge isto understand people’s approach to the utilisa-tion of services and to make decisions at thepolicy level. This may well lead to a situationwhere there is a need for society to undergo afundamental change in the way that it thinksabout jobs and service delivery.

KnowledgeSeveral things are needed to transform to aknowledge value society. One of them obvi-ously is knowledge, which has always been atrigger for the development of a society. Theintroduction of a systematic education systemfor the general public in Europe a few hundredyears ago created the base for many of theinnovations responsible for transforming theagro-oriented society to an industrial society.We can assume that ‘Knowledge’ is closelylinked with the educational system and LifeLong Learning (LLL). Europe has a long tradi-tion of cultural and educational diversity.Educational systems have developed to meetthe specific requirements of individual States. There is considerable variation in the amountof control over the professions administered

plinary knowledge coming together, it is neces-sary to combine and reconnect the requiredknowledge. The implementation of inter-institu-tional projects requires a balanced mix ofexploration and exploitation of knowledge,where exploration is more important in theconceptual phase, and exploitation becomesmore fruitful in the implementation phase. Good ideas come from people with talentworking together. Professionals, such asTabberer, emphasise the need for organisa-tions to be not only reasonably good at man-aging data (maps) and information (planningprocesses) but also at managing knowledge(or: profiting from ‘lessons learnt’ in a wayothers can readily use). This approach appliesnot only to institutions but also to wholeregions such as the European Union, and alsoto the worldwide non-governmental organisa-tion of professional surveyors, FIG.

Knowledge ArtefactsWhenever people communicate they conveyknowledge and skills highly contextualised totheir and their partner’s current work situation.The way of creating, managing and dissemi-nating knowledge artefacts (for example a pro-tocol of a meeting) has already changed con-siderably in recent years. The integration ofspatial information with all the temporalaspects will increasingly be embedded in deci-sion-making processes leading to optimiseddecision making and transparency.Communication, cooperation and networkingas bases for knowledge sharing processes willcreate a shifting mindset that is more efficientand dynamic enabling geodata to be usedmore effectively in the development of a mod-ern society.

Gerhard Muggenhuber ([email protected]) is head

of FIG-Commission 3 ‘Spatial Information

Management’. Rob Mahoney FRICS FBCartS

([email protected]) is Principle of MahGeoan

Independent Consulting Company based in the UK.

by the State which in turn has led to the situ-ation where licences to practise are required insome jurisdictions, and this has a negativeimpact on the mobility of surveyors.Improvements have already been achieved onthe educational level where the Bologna pro-cess has been initiated to ensure a har-monised academic education standard acrossEurope allowing young people to becomemore flexible. Degrees awarded across Europewill provide certified levels of education andencourage cross border recognition, which inturn will provide greater work force mobility.On the professional level CLGE (Comité Liaisondes Geométrès Europeéns – www.clge.org), aswell as the ECEC (European Council ofEngineers Chambers – www.ecec.net/java/seit-en/index2.jsp) are working on the harmonisa-tion of professional qualifications in geodeticsurveying.

Focus for the FutureKnowledge sharing processes will be, andalready are, a central feature of the functioningof governments as well as of many organisa-tions. The importance of knowledge sharinghas become even more evident with the riseof e-government projects, as these have a net-working effect on bureaucracies, bringingtogether individuals from different organisa-tional units, with different models, to work ona common goal: the implementation of a pro-ject. With multiple agencies and multidisci-


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Honorary guests at the Austrian Geodetic conference in Krems, May 2006.

Knowledge sharing processes

will be, and already are,

a central feature of the

functioning of governments

as well as of many

organisations.

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‘What the Macro World NeedsInterview with Ola Rollén from Hexagon AB‘What the Macro World Needs

So far GeoInformatics has had interviews with Hans Hess, former CEO of Leica

Geosystems (GeoInformatics 7- 2005), Richard McKay, vice president sales and Sara

Upchurch, marketing communications manager with the Geospatial Imaging Division of

Leica Geosystems (GeoInformatics 1-2006). Since it is quite clear that we will hear

more of Hexagon in the future, we wanted to give you readers an impression of the

company and the person leading this organisation.

By Sonja de Bruijn

Three Business AreasHexagon AB, with headquarters inStockholm, Sweden, offers global technolo-gies and does not really focus on a specificmarket. The company covers three businessareas: Measurement Technologies, Polymersand Engineering, of which the first one repre-sents 75 per cent of Hexagon’s business. (45– 50 per cent before the take-over of LeicaGeosystems). Measurement technology head-quarters are situated in London, and salesturnover amounts to about 1.5 million USD.The organisation has 7,500 employees inthirty countries, of which about 5,000 areactive in measurement technology depart-ment.

Since the acquisition of Leica GeosystemsHexagon has been listed on the Stockholmand Zurich stock exchanges

Core BusinessesFive years ago Hexagon was a smallScandinavian company engineering conglom-erate with 500 million euros turn over insales. “When I took over the management ofHexagon I decided to continue to growrapidly, but to focus on a few strategic corebusinesses”, says Ola Rollén, CEO ofHexagon. In order to increase sales a newstrategic plan was formed. Part of this planwas the disposal of Hexagon Automation,representing 37 per cent of sales, and this

took place in the summer of 2005. At thesame time Hexagon made a bid for LeicaGeosystems. Rollén makes clear that there is a strongemphasis on growing Hexagon’s marketshare; being number three in the market isout of the question. He explains what hethinks makes Hexagon a strong company:“We focus on precision products and theseshould make a difference for our customers.This means that they should see that theybenefit from our products. We regard our-selves as being the innovators and havingcost leadership because then you can defendyour market share.” In measurement technology there are threemarkets where Hexagon has the intention ofbecoming a leading player: the macro, microand nano market.

Micro MarketBy the end of 2005 Hexagon acquired LeicaGeosystems. What differences and similaritiesare there between the two companies? “Weoffer our customers technology to positionand measure objects and functional accuracyand range”, is Rollén’s answer. “The marketLeica Geosystems is active in has traditional-ly been a 2D world but it is moving to 3D.‘Our’ market, the micro market, has alwaysbeen in 3D so we are specialist in creatingsoftware products and measurement technol-ogy in three dimensions.” To make things clear Rollén compares mea-suring the Mount Everest and a siliconwaver. “The accuracy might not be that pre-cise when measuring a big object like amountain, but that is not really important.However if you want to measure a siliconwaver the measurement range might be twocentimetres and the accuracy needed mightbe below a micron of a millimetre. The thingis that you use the same mathematical algo-rithm to determine what it looks like and thesame basic technology to measure it.” “Traditionally the macro market was allabout measuring the distance and the angle.Now with 3D you really get an idea of whatthe object looks like in the real world.Images are captured from the air in 3D, thenlaser scanning is applied to compare thedata. Accordingly three-dimensional softwarewill interpret all this and create a very

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Interv iew

Ola Rollén, CEO of Hexagon.

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detailed 3D image of the real world whichcan be used in areas like construction,machine automation, and surveying. 3Dmodelling will enable construction people tohave a sensible communication with archi-tects, one of the big problems in construc-tion. This is the future of the macro worldand the way the micro world already works.”Handheld laser robots, large sophisticatedsystems to measure for example interconti-nental strategic missiles, total stations, aero-planes, software to capture and interpret thedata, all these hi-tech systems can be usedto measure objects. Operators need to betrained and software upgraded which accord-ing to Rollén ‘creates a nice aftermarket forHexagon’.

Real WorldRollén is convinced the macro field willbecome as sophisticated as the micro field.He mentions the automotive industry: “Theearly adopter of new technologies often isthis industry, who really needs new technolo-gy to be able to reduce costs. This need andunderstanding is spreading to other indus-

Joint ProjectsOn the other hand the micro world needsthe development of laser scanners from themacro world. Hexagon Metrology and Leicaare currently working on this in five jointdeveloping projects. Rollén: “We are aimingat two things: introducing our software andservices into the macro world and introduc-ing the laser sensor technology into themicro world. Four years ago we started look-ing at this development and have been fol-lowing Topcon, Trimble, Sokkia and Leicasince that time. The first two were highly val-ued on the stock market, Sokkia had aweaker position. In Leica we found a strongmerger with Hexagon Metrology. Now wewant to grow Leica’s presence in the macroarea. We expect to have 18 per cent marketshare in the macro market in 2008 and wewould like that to grow. Leica has had aweaker position in its distribution in NorthAmerica compared to Europe so we are aim-ing at strengthening this position in NorthAmerica.”Rollén further explains that as a companyLeica Geosystems will not change as such.“The Hexagon- Leica Geosystems relationshipis more of an R&D collaboration in order tolaunch new products both in the macro andin the micro world. What does need to bechanged is its position in the micro world,where Leica Geosystems is quite unknown.”Rollén also wants to make clear that most ofthe cost issues in geospatial imaging divi-sion have been addressed. “What we wantis the platform to become better, get it backon track, since it is the growth area for thefuture. Nowadays it is all about 3D softwarefor referencing, interpreting, and capturingdata. It is my belief that airborne 2D and 3Dimages and the land-based measurementmarket will eventually converge. They gohand in hand, and new systems that com-bine these will emerge. It is a market inwhich we only want to grow.”

Sonja de Bruijn ([email protected])

is editorial manager of GeoInformatics.

More information via www.hexagon.se.

tries. Just have a look at the building con-struction market. If the automotive industrywould work in the same way, it would takeyears to build a car. There is much pressure,very high accuracy is needed. Furthermorethe price of a car has gone down. How doyou deal with this as a car manufacturer? Inconstruction many mistakes appear; thingsdon’t fit et cetera. 3D is spreading in theconstruction and geoinformatics worldbecause there is a developing need for it inthe market. Increasing the quality is becom-ing more essential.”He continues: “Manufacturing costs need tobe decreased and this requires more preci-sion in measurements, plus more sophisticat-ed models and software systems. This isalready happening when you look at scan-ning technologies and GPS systems.Hexagon has been working like this fortwenty years and we see that we are furtherahead when it comes to integration withsophisticated CAD systems, and referencingand extracting useful information out of thehuge information flow from for example apoint cloud.”


Interv iew

is 3D’is 3D’

“3D is spreading in the construction and geoinformatics world

because there is a developing need for it in the market.

Increasing the quality is becoming more essential.”

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 15

Ground-Based Aerial PhotoSpectacular Growth in Recent YearsGround-Based Aerial Photo

Over the last few years, there has been a spectacular growth in the acquisition of low-altitude aerial photography taken from

heights of 200m (600 ft.) or lower. In the past, this has been a difficult environment for the operation of manned aircraft, both in

terms of air traffic restrictions and on grounds of safety, especially over urban areas. However new developments in platforms and

digital imagers are now allowing low-altitude aerial photography to be obtained in a more or less routine fashion. A big advantage

of these new developments is that the airborne imaging can be carried out and controlled remotely from the ground without the

need for and the expense of sending someone into the air to execute the operation.

by Gordon Petrie

Different TechniquesSeveral different techniques have been developed for the acquisition of remotely-controlledground-based aerial photography from low altitudes. Ranked in terms of their actual usage arethe following:-

(1) vehicle- and tripod-mounted telescopic masts;(2) remotely-controlled mini-helicopters;(3) un-powered (tethered) balloons and blimps;(4) powered (un-tethered) balloons and blimps; and (5) tethered kites.

1. Aerial Photography UsingTelescopic Masts

(a) Mast ConstructionA considerable range and variety of telescopicmasts have been developed for low-levelaerial photographic operations by systemsuppliers both in North America and inEurope. These masts can be raised to maxi-mum heights ranging from 13 ft. (4m) up to

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Figure 1 (a) - A mobile van equipped with a 80 ft. (24m) telescopic mast that is used to obtain elevated (aerial) photography using a film, digital or video camera. This particular van belongs to High Level Photography Ltd. based in Guildford, Surrey. The company owner, KeithHallam is standing in front of the vehicle. (Source: High Level Photography)(b) - An alternative configuration for photography using very tall masts (up to 100 ft.[30m]) is for the telescopic mast to be mounted on a trailer that is towed by a four-wheel drive vehicle. (Source: Cloud 9 Photography)

(a) (b)

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100 ft. (30m). However these are the extremeends of the height range; the majority ofthose masts being operated for the acquisi-tion of aerial photographs in the U.K. reachmaximum heights of 50 to 65 ft. (15 to20m). These masts are usually mounted onvehicles, often equipped with four-wheeldrive to be able to reach off-road sites. Theshortest masts are constructed from quitenarrow diameter tubes of lightweight alu-minium alloy that fit (and telescope) intoone another. Typically these very short mastswill have a 3 inch (7.5cm) diameter for thebase tube and a 1.5 inch (3.75cm) diameterfor the top tube. At the other end of theheight range are a few masts that can beraised to up to 100 ft. (30m). Typically thesemasts will have base tubes that are 5 to 6inches (12.5 to 15cm) in diameter and com-prise six to eight tubes that telescope intoone another. When retracted down for trans-port, the height of the shorter masts mayonly be 5 ft. (1.5m). Thus they can be left inposition if fitted to the back of a vehicle.With the longer masts, the retracted heightwill be 8 to 10 ft. (2.5 to 3.5m). These willusually be transported on the roof of thevehicle or occasionally on a towed trailer.

(b) Mast WeightsThe weights of the masts will vary accordingto their length - from perhaps 30 lbs. (13kg)in the case of the very shortest masts to 80lbs. (36kg) for a 20m mast to over 220 lbs.(100kg) for the tallest heavy-duty masts.These sizes and weights have big impact onthe usage of the masts. The shortest andlightest models can be mounted on suitabletripods equipped with adjustable legs andplaced on small hand-drawn trolleys or cartsfor local mobility. The longer, heavier modelsneed to be mounted directly on vehicles ortowed on specially-built trailers to the site oftheir operation. The size and the weight of aspecific mast also have an impact on itsactual operation. The shorter ones can beraised or lowered either manually or using ahand crank. The taller, heavier masts need tobe raised using a power source. A system ofwires and pulleys driven by electric motors isused in the masts constructed by theCanadian Luksa Industries company. An alter-native is to use a pneumatic system employ-ing compressed air to raise the telescopic

and is much less likely to cause an obstruc-tion to traffic than having to hire and posi-tion a large crane or cherry-picker - whichwas the method used previously in such situations. The routine photography of build-ing and construction sites to monitor andrecord progress and to authorize paymentsfor the actual work that has been done isanother widespread application. Needless tosay, estate agents often commission low-level mast aerial photography of sites andbuildings that they wish to sell. The elevatedimages ensure that the resulting views of thebuildings and sites are no longer obstructedor hidden behind hedges, trees, walls, fencesor other buildings. Yet another commonapplication is to take low oblique aerial photography of traffic accidents or crimescenes for use by police traffic and criminalinvestigation departments. In these situa-tions, the resulting images can be handedover to police officers on compact disks atthe actual scene of the accident or crime orthey can be sent via phone lines or over theInternet to the appropriate police authority,emergency service or media organization.Panoramic images of individual large roomsor halls indoors within buildings can even be taken using a very short mast mountedon a tripod. In the U.K., there is an extensivenetwork of more than 50 mast aerial photog-raphers who compete strongly for business,especially in the densely populated and veryprosperous parts of Southern England andthe West Midlands.

2. Remotely-Controlled Mini-Helicopters

The field of powered radio-controlled modelhelicopters is one that has been active forsome time with many thousands of enthusi-asts pursuing it as a hobby and the moreserious ones competing in national andinternational aerobatic competitions.However recent developments have led tothe introduction of somewhat larger remotely-controlled mini-helicopters that are designedspecifically as platforms for aerial photography.Before anyone thinks that this is some kindof fringe activity, there are already over 70small companies in the U.S.A. engaged inthis activity that are listed in my Web LinksDatabase. Indeed the rapid development inthis field has led to the establishment of the

tubes. This is the system used by the ClarkMasts company which has factories both inthe U.K. and Belgium. Power for all of thesetaller systems is normally supplied by a suitable 12 volt DC battery.

(c) Mast CamerasFor mast photography, high-quality SLR filmcameras equipped with motorized filmadvance mechanisms are still being usedquite extensively in conjunction with a tinyvideo camera placed behind the viewfinder.This allows the correct pointing of the filmcamera towards the desired object or area to be carried out under the control of theoperator based at ground level. However,nowadays, many operators use digital framecameras. A few are now using panoramiccameras that provide 360° coverage of thewhole area around the mast. Whichever typeof camera (film, digital or video) is beingused, it is mounted on a motorized pan-and-tilt head that is fitted to the top of the mast.This allows the pointing and coverage of theframe camera image to be controlled veryprecisely by the operator - using the joystickforming part of a control unit located in thevehicle or placed on the ground - before theimage is actually exposed. During this set-upoperation, the camera image is being trans-mitted down via a video cable either to thepurpose-built control unit (which is equippedwith a display monitor) or to a laptop computer having suitable control software.This arrangement allows the operator - andeven sometimes the client - to spend timeover the composition and timing of the aerial image. The actual exposure of theimage is implemented using a remote shutter release. On a very sunny day, a sun-shade or hood will be placed over thecontrol unit or laptop computer to eliminateglare on the screen of the display monitor.

(d) ApplicationsThe low oblique aerial photography acquiredusing these telescopic masts finds numerousapplications. Acquiring imagery for use inurban modelling is an obvious photogram-metric and GIS application, as its widespreaduse by architects, planners and site develop-ers. The mast method is relatively simpleand unobtrusive to implement. It is alsomuch cheaper and quicker to produce results


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graphygraphy

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Remote Control Aerial PhotographyAssociation (RCAPA) in the United States towhich most of these companies belong.More details about the activities of theAssociation and its members can beobtained from its Web site - www.rcapa.net/ .In the U.K., there are at least 10 similar com-panies and there are a number of othersscattered throughout the rest of WesternEurope.

(a) Mini-Helicopter PlatformsThe mini-helicopters that are used in aerialphotographic work are typically 5 to 6 ft. (1.5 to 1.8m) in length with the main rotorblade having a diameter of 5 ft. (1.5m). Mostfeature a skeletal frame of lightweight alu-minium tubes. However some newer modelsare being constructed using a verylightweight but very rigid frame made of carbon fibre. The power for the smaller models of mini-helicopters is provided by anelectric motor that gets its power from a setof small rechargeable batteries. These motorshave the advantage of being almost silent intheir operation, which is a big advantage innoise-sensitive areas. On the other hand,electrically-powered mini-helicopters are alsolimited in their flight duration and in theirlifting power. Therefore the more powerfultypes of mini-helicopter are powered by verysmall petrol (gas) engines. For example, theBergen Observer - which is purpose-built foraerial photography - uses a Zenoah 26ccpetrol engine that allows a payload of 8 lbs.(3.6kg) of camera and radio control equip-ment to be carried. The still more powerfulBergen Observer Twin uses a twin-cylinderZenoah engine with double the enginecapacity (52cc) and generating 8 horsepower.This allows a payload of 20 lbs. (9kg) to becarried, including a built-in pan-and-tilt sys-tem for the camera. This motorized pan-and-tilt system sits on a special anti-vibrationmount that isolates it from the mechanicalvibration of the mini-helicopter. Enough fuelcan be carried by the Observer helicopters to provide half-an-hour's flying time. Otherpurpose-built mini-helicopters for use in professional aerial photography include theMaxi-Joker 2 machine that is manufacturedby the Minicopter company in Germany.However this is powered by a electric motordriven by batteries. Thus the weight of itspayload is limited to 4.5 lbs. (2kg) and theflight time is reduced to 20 minutes. Anothernew development from Germany is theDigiFLY that has been developed by the IGIcompany that is well known for its CCNS andAEROcontrol flight management systems foraerial photography. This platform uses fourpropellers driven by brushless electric motors

(b) Mini-Helicopter CamerasIn the main, the companies operating mini-helicopters equip them either with medium-format (6 x 4.5; 6 x 6; or 6 x 7cm) film cameras fitted with motorized film transportmechanisms and zoom lenses or, more usually nowadays, with lightweight small-for-mat digital frame cameras that produce rela-tively high-resolution images with an imagesize of 6 to 14 Megapixels. Alternatively, ifthe client requires video imagery, then smallhigh-quality video cameras will be used. Afew operators have also utilized lightweighthigh-definition video (HDTV) cameras to capture ground images. In the larger mini-helicopters, a motorized gimbal or pan-and-tilt mount is used to carry the camera. A miniature radio transmitter/receiver unitmounted in the helicopter receives theappropriate signals from the operator's control unit on the ground. These signals arepassed to the motors both on the cameraand on the camera mount to carry out theappropriate movements - pan left/right; tiltup/down; zoom in/out - to ensure the correctpointing and coverage of the camera. Asnoted above, these movements of both themount and the camera are isolated from thevibration of the helicopter as much as pos-sible. On exposure, each image is transmit-ted at high speed via a wireless video downlink to the control unit on the groundwhere it is displayed on the monitor screenof the unit and recorded. Later the capturedimages can be imported into a CAD or GISsystem on which the relevant map of thearea is stored, so that the images can begeo-referenced.

(c) ApplicationsObviously quite a number of the possibleapplications of the images acquired by themini-helicopter will overlap with those thatcan be implemented using a telescopic mast.These will include the monitoring of con-struction sites. In this respect, the telescopicmast can often operate more closely to thespecific building or structure being inspected,especially in urban areas. Whereas the mini-helicopter, operating at a greater altitude,can provide the wider coverage needed for alarge site. The mini-helicopter is, of course,also well suited to the acquisition of imageryof wetlands and swampy areas for environ-mental assessment and analysis wherewheeled vehicles equipped with masts can-not operate or penetrate. The higher operat-ing altitude of the mini-helicopter is alsoadvantageous when woodland has to beassessed from an overhead position ratherthan at the low oblique angle given by themast. When equipped with a video camera,

and features an integrated GPS/IMU/barometercombination to provide an electronic flight-stabilization system. Various types of imager- digital, thermal-IR or video - can be usedto provide the imaging of the ground. Thelatest development in this field is to fit smallgas turbine engines to mini-helicopters. Thisincreases the available power very substan-tially and therefore the payload that can becarried - but at a very substantial financialcost.


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Figure 2 (a) - The Bergen Observer EB remotely-con-trolled helicopter equipped with a Zenoah G-26 petroldriven engine. A pan-and-tilt system on which thecamera is mounted is located at the front end of thehelicopter and provides a 270° field of view. The pan-and-tilt system is isolated from the helicopter mechan-ical elements through the use of four heavy-duty isola-tors. (Source: Bergen R/C Helicopters)(b) - One of the radio-controlled helicopters that isoperated by the High Spy Company in the U.K. Thisparticular example utilizes a frame built by theGerman manufacturer, Vario Helicopters and aZenoah 23cc petrol engine. The on-board electronicsinclude a 3-axis gyro-controlled camera mount, a GPSset, a magnetic compass and a barometric height sen-sor. (Source: High Spy)(c) - This electrically powered Maxi-Joker radio-con-trolled helicopter was designed specifically as an aeri-al camera platform and was built by the Minicoptercompany based in Vollmer, Germany. (Source:Minicopter)

(a)

(b)

(c)

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 19

the helicopter also provides a highly mobileplatform from which continuous video 'fly-over' imagery of the ground can be generat-ed. However it must also be said that themini-helicopter is much more likely to be at risk from damage through engine failure,loss of control or flight into an obstructionsuch as telephone or power lines. Specialcare needs to be taken in urban areas wherethe risk to both people and property couldbe high. It is interesting to note that someaerial photographic companies operate bothtelescopic masts and mini-helicopters, thusallowing them to select the most suitableplatform for a particular task.

3. Un-powered (Tethered) Balloons &Blimps

(a) Balloons and BlimpsAs is well known, the very first aerial photo-graph was taken from a tethered balloon overthe Bievre Valley in France by Gaspard FelixTournachon (better known by his nom-de-plume as 'Nadar') in 1858 - nearly 150 yearsago! Even at that time, it was apparent thatun-tethered balloons were not suitable plat-forms for the acquisition of aerial photogra-phy - since they simply travel where the windtakes them and not necessarily over the tar-geted area. Still it is worth noting that spheri-cally-shaped un-tethered balloons are being

used extensively for certain types of scientificresearch - for example, by NASA undertakingatmospheric and astronomical research atultra-high altitudes (120,000 ft. = 36km ormore) in the stratosphere. However thesehigh-altitude research balloons do not need toreach or stay over a specific area or target onthe ground - as is required for aerial photog-raphy. Instead streamlined aerodynamically-shaped blimps equipped with fins arranged inan X- or Y-shaped configuration that providemuch more stability are used for low-altitudeaerial photography. The blimp envelope ismade of a lightweight polyurethane-coatednylon material that is highly resistant to beingtorn. The fins are sometimes made from a stiff

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Figure 3 (a) - This 18 ft. (5m) long helium blimp belongsto the PhotoComAsia company and is based in Bangkok,Thailand. The position and height of the platform is con-trolled by the tether rope attached to the front of theblimp. The camera and its mount are suspended byadditional ropes attached to the middle of the blimp'senvelope. (Source: PhotoComAsia)(b) - A tethered blimp operated by the Skycell company ofYork, England is being launched to acquire aerial pho-tography of the Roman amphitheatre in Chester.(Source: Skycell Ltd.)

(c) - An oblique aerial photograph of part of the Castle Howard estate located near York, England taken from a tethered blimp. It includes the magnificent 18th Century mansion withits distinctive dome (in the background); an ornamental bridge (in the middle ground) and the Mausoleum (in the foreground). (Source: Skycell Ltd.)

(a) (b)

(c)

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 20

but lightweight composite material. Evenwhen tethered, these blimps can only be usedas stable camera platforms in fairly calm con-ditions or at very low wind speeds - below 10mph (15 kph). Nevertheless, in spite of theselimitations, there are now quite a substantial number of commercial operators usingunmanned, tethered blimps routinely for aerialphotographic purposes in the more highlydeveloped countries of North America,Western Europe and Australia. Most of theseblimps are quite small in size - typically 10 to20 ft. (3 to 6m) in length. Costs are kept lowsince there are quite a number of competing manufacturers who build blimps inquantity for commercial advertising purposes.

(b) Helium Blimps v. Hot-Air BalloonsRegarding the blimps and balloons used forlow-altitude aerial photography, there is achoice to be made between the differentlighter-than-air gases that can be used as thelifting medium within the envelope. Sincehydrogen and methane are both highlyflammable gases, for safety reasons, they arenot suitable for use in blimps and balloons.So the choice really lies between helium andhot-air. For a given volume, helium has amuch greater (5x) lifting capacity than hot air,which is produced using a propane burner

in Canada, use a |calibrated photogrammetriccamera (such as the RolleiMetric) designedspecifically for mapping purposes. Each film ordigital camera will also have a tiny auxiliaryvideo camera fitted to it for viewing purposes.The camera will sit in a motorized mount thatis controlled from the ground. This allows it tobe pointed in the required direction and givethe desired coverage. The pan-and-tilt mountis often attached to a keel or rail fitted alongthe bottom of the blimp. Since the blimp willbe tethered using a strong but very light-weight rope or cord, the control signals andthe digital images being downloaded aftertheir exposure will usually be transmitted toand from the control unit on the ground usinga video cable attached to and wound roundthe tether rope. However some operators usea wireless (radio) link to transmit signals andvideo image data to and from the blimp. Incalm conditions, the tether rope attached to asmall blimp can be attached at the other endto a harness worn by the camera operator onthe ground. He can then walk and manoeuvrethe blimp into the correct position with the aidof the portable video monitor of the controlunit. However other operators attach the teth-er to a small winch equipped with a crankhandle to control the length of the line thathas to be paid out. To change the film or thecamera lens, the blimp is simply brought backdown to the ground by hand or using thewinch and crank handle, an action that onlytakes a few minutes to complete. The blimpcan then be re-launched as soon as therequired changes have been made.

(d) ApplicationsAs for the applications of blimp aerial photo-graphy, many of these will be the same asthose described above for mast and R/C helicopter photography - especially the monitoring of construction sites and the elevated oblique photography of properties that are being developed or put up for sale.The tethered blimps can be operated at flying heights of up to 400 ft. (120m) withoutthe need to obtain permission or file flightplans with the air traffic control authorities -though operation over or near to defenceinstallations and around airports and air-fields is strictly controlled. This ability to fly blimps at greater altitudes than can beused with telescopic masts allows them toachieve greater area coverage of the groundand the use of steeper angles if this isrequired. In this respect, blimps competewith R/C helicopters. Indeed quite a numberof service providers of ground-based aerialphotography use masts for altitudes up to 75 ft. (23m) and blimps if still higher altitudes are required.

attached to a suitable storage tank. So a hot-air balloon must be much larger in terms ofits size and volume for a given lifting capaci-ty and is correspondingly more expensive tomanufacture and to buy than a helium blimp.Thus almost all aerial photographic blimpsuse helium which is available stored in trans-portable steel cylinders at a fairly low cost inmost highly developed countries. Howeverhot-air balloons do have one small advan-tage in that propane is much more readilyavailable in small easily-transported tanks -since it is used extensively for heating andcooking purposes world-wide. With the heli-um blimps, the gas is sometimes releasedinto the atmosphere once the aerial photo-graphic session has been completed - since itis very difficult, indeed impractical to return itto the storage cylinder. However, nowadays,most commercial aerial photographic opera-tors transport the small blimp fully inflated ina suitable towed trailer. In which case, thegas will not be vented deliberately into theatmosphere - though it will do so slowlythrough leakage over a period of time.

(c) Blimp CamerasThe types of camera and the mounts that arecommonly used for the aerial photographybeing taken from blimps are similar to thosediscussed above in the context of masts andR/C mini-helicopters. Either |motorized medi-um-format film cameras such as the Pentaxand Mamiya models with a |6 x 7cm format orsmall- to medium-format digital cameras arecommonly used. A few operators, e.g. Dartmap


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Figure 4 (a) - A powered balloon operated by SkycellLtd. acquiring photography in Wells Cathedral inSomerset, England. The ducted propellers can be seenon each side of the balloon with the digital camera onits mount hanging down from the centre of the mainenvelope of the balloon. (Source: Dr. Szymanski,University of York)(b) - A powered blimp operated by the av8pix companybased in Guernsey in the Channel Islands acquiringphotography in the nave of Hereford Cathedral in thewest of England. (Source: av8pix)(c) – A lightweight gondola slung below the poweredblimp showing the camera housing and ducted propellers. (Source: av8pix)(d) - A blimp with its trailer-cum-hanger that is beingtowed by a four-wheel drive vehicle. (Source: av8pix).

(a) (b)

(c)

(d)

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 21

4. Powered (Untethered) Balloons & Blimps

The fitting of engines to provide power toblimps and balloons means that they can beoperated without tethers to much higher alti-tudes and enables them to carry a muchgreater payload. These characteristics lead tothem being described sometimes asunmanned mini-airships. While some ofthese platforms are being used purely foradvertising purposes, quite a number arenow being used for the acquisition of aerialphotography using still (frame) film, digitaland video cameras. With the availability ofmotors, blimps can carry out a larger andmore systematic photographic coverage in amuch shorter time.

(a) PlatformsThe powered blimps can be equipped eitherwith electric motors or petrol-fuelled engines,giving forward speeds of up to 30 knots(55kph). As with the R/C mini-helicopters, theuse of brushless electric motors gives a near-silent operation, whereas the use of petrolengines provides a substantial increase inrange, endurance and payload. Howeveroccasionally problems may be experiencedwith noise and exhaust smoke emitted bypetrol engines. Whichever type of engine isused, typically they drive three-bladed duct-ed propellers. These can be vectored (tilted)over a considerable range to provide thecontrol of the powered blimp or balloon in-flight using the radio-control signals beingtransmitted from the ground control station.A GPS-based autopilot is sometimes used forthe main (photographic) flight, although thetake-off and landing of the blimp will still be

licity, including being fea-tured on national televi-sion. The surveys haveincluded the systematicphotography of both theexterior and interior oflarge churches such asYork Minster and Hereford,Wells, Winchester andGloucester Cathedrals.These images now formpart of the NationalMonument Record of theEnglish Heritage organisa-tion. Skycell has also car-ried out imaging surveysof the RomanAmphitheatre in the city ofChester that is currently thesubject of an investigativeand renovation projectbeing carried out by

English Heritage and Chester City Council.The resulting images have been used to con-struct a computer-based model of the site.

5. Tethered Kites

The golden age of kite aerial photography(KAP) was the 15 year period prior to WorldWar I. However, with the development of aircraft, kite aerial photography almost diedout. Over the last 20 years, it has regainedsome ground and is now pursued as ahobby by hundreds of enthusiasts world-wide. It is also being used as an aid to certain research activities in geomorphologyand hydrology by a small number of univer-sity field scientists. Still it is difficult to envis-age kite aerial photography being adoptedcommercially as a standard technique. Mostof the very small number of commercialoperators that offer kite aerial photographydo so as a supplement to one of the otherground-based techniques described above.

6. Conclusion

Ground-based aerial photography has devel-oped rapidly over the last few years and hasnow become firmly established in certainmore highly developed countries. Furtherdevelopments in platforms in combinationwith the new forms of digital imaging willalmost certainly lead to its spread and adoption on a world-wide basis.

Gordon Petrie ([email protected]) is Emeritus

Professor in the Dept. of Geographical & Earth

Sciences of the University of Glasgow, Scotland, U.K.

controlled manually. Since the size of theblimp is quite small - typically up to 30 ft.(9m) in length and 9 ft. (2.5m) in diameter -it is usually transported fully inflated in aspecially-built trailer. The trailer also acts asa protective hangar when away from thebase and carries the helium storage cylin-ders.

(b) CamerasThe powered blimp is usually fitted with avery lightweight gondola made of carbonfibre, as are the ducts that shroud the pro-pellers. This gondola carries the motors; there-chargeable batteries and the transmitter/receiver used for control purposes. Typicallyit will also carry a lightweight rotatable cam-era mount, again made of glass- or carbon-fibre that allows a 360° (pan) rotation and afull range of tilt movements. In some cases,the mount is gyro-stabilized. The actual cam-eras that are used inside this sophisticatedmount are the digital, film and video cam-eras described above in the section on teth-ered blimps.

(c) ApplicationsObviously the use of a powered blimp allowslow-altitude aerial photographic surveys tobe undertaken over more extensive areas ofthe terrain in a timely manner than is practi-cal using an unpowered blimp employingtethers. In the U.K., an extensive series ofsurveys of churches and other historic build-ings has been carried out by two commercialoperators of powered blimps - av8pix andSkycell. These have largely eliminated theneed for and the associated costs involvedin erecting scaffolding. Needless to say,these surveys have generated extensive pub-


Art ic le

Figure 5 (a) - Aerial photography is being acquired in this photo using a Flowform kite being flown by Scott Haefner of Palo Alto,California. The Nikon digital camera is attached to the main tether line using a set of Picavet suspension cables that carries the cross-shapedbase plate and the camera mount. (Source: Scott Haefner)(b) - A detailed annotated photograph of the camera set-up devised by Dennis Williams of Clinto, Massachusetts, which he uses to acquirekite aerial photography (KAP). (Source: Dennis Williams)

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‘The Possibilities Are UnlimiESA Actively Promotes Earth Observation Products‘The Possibilities Are Unlimi

Remote sensing from satellites or Earth Observation (EO) can be useful in many appli-

cations. The potential value of earth observation products and services has long been

well recognised. However, despite rapid progress over the years, many users feel that

these products and services still fall short of expectations or present limitations in

their effective use.

By Robin Wevers

PotentialThe market for earth observation productsand services has remained small when com-pared to the cost of developing spaceassets. Although the potential of the com-mercial market is still considered to be large,it has become clear that the optimistic fore-casts of the early 1990’s regarding thegrowth of commercial exploitation of EO mis-sions have not been realized. Nowadays, it iswell understood that the market is difficultto be exploited without accompanying mea-sures. Within this context the ESA started the

Earth Observation Market Development(EOMD) initiative in 2000. The EOMD has the objective to foster theuse of Earth Observation (EO) based geo-information services within various marketsectors. Stephen Coulson, Head of theIndustry section of the Earth ObservationPrograms at ESA, gives his views of thedevelopments. “EOMD means the first timefor ESA to directly support the market devel-opment phase of satellite-based productsand services. The approach has been to'plug-in' information from space into conven-

tional information services in order toimprove or enhance what is on offer.Coulson says: “To convince customers of thebenefits of earth observation EOMD has car-ried out 75 trials involving about 130 cus-tomers focussing on 20 main service portfo-lios. Examples include geological mapping,land subsidence monitoring, flood mapping,monitoring of agricultural crops, detection ofships and monitoring of oil spills.”

CharacteristicsCoulson explains the characteristics of earthobservation: “It is quite simple: satellites areflying around the world, ‘seeing’ the 'big-pic-ture'. They do not distinguish between differ-ent countries, languages or cultures.Satellites are extremely stable pieces ofequipment and provide the same type ofinformation wherever and whenever they are.These may seem like simplistic statements,but are in fact very important. To give anexample, we have been working with an oilproducer who operates a number of drillingwells in the US. This oil producer constantlyneeds information on the land subsidencethe oil production causes, as wells can easilycollapse. Of course, this can be done onground level, but this is expensive and pro-vides local information only. Satellites canmeasure small movements, in centimetres orless, of the land surface. Within 15 secondsa satellite can image an area of 100 x 100km and provide tens of thousands of mea-surements. It can do this once a month, fora long time. A lot of people worrying aboutsubsidence are simply unaware of these pos-sibilities. Now the US oil company is one ofour biggest converts: they regularly buy anduse this type of information from satellitesfor their operational business.”Coulson is the first to admit that satellitesalso have their limitations: “They are expen-sive. However, the commercial costs of satel-lite data are coming down and this opens upmore possibilities for services using thesedata. It is a value-for-money issue. Here, Ithink that companies in the EO satellite ser-vices sector can improve. They need to keepthe focus on the customer, and not let thetechnical wizardry get in the way.”Another limitation of EO is the limited tem-poral and spatial resolution and the inabilityof optical sensors to see through clouds.

June 200624

Interv iew

East Mediterranean region as seen by ESA Envisat satellite (Medium Resolution Imaging Spectrometer instrument)on 21 July 2004. The Eastern Mediterranean Sea area is vulnerable to earthquakes and Earth Observation satelliteimages are useful for providing updated views of how the landscape has been affected as well as creating referencecartography for emergency operations. Courtesy of ESA.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 24

These limitations of earth observation datacan only be overcome by combining thesedata with in-situ measurements, which pro-vide the calibration data necessary for vali-dation.

Market AnalysisCoulson about the current market: “First letme say that currently the earth observationmarket is small. Studies estimate that thetotal revenues from Earth observation ser-vices across Europe are about 250 - 275 mil-lion euros in 2002. The optimistic forecaststhat EO would become fully commercial havenot come true. Nowadays, it is recognisedthat the market is difficult to exploit and thatis why we have a program like EOMD. Themarket is now emerging from a long periodof stagnation. Currently we are seeing growthin commercial sales of services, particularlyin the areas of land motion, geological map-ping and maritime surveillance.”According to Coulson there are still somemarket segments that have serious as yetunexploited potential for the EO-industry:“We live in an age where information is oneof the most valuable assets in business. Thepossibilities are unlimited. We are now start-ing activities to test what Earth Observation

start of a big joint initiative between theEuropean Space Agency and the EuropeanCommission to put space to work for thebenefit of European environmental and secu-rity policies. The pollution of our water, thestate of our forests, cities and countryside,and the quality of the air we breathe arevery much of interest to us all. GMES shoulddeliver information services to a whole hostof international, national and regional agen-cies and organisations who are legally man-dated to care for and protect our environ-ment and need information to do this. Inaddition, GMES should give industry theopportunity to 'spin off' a wide range ofnew commercial services, some of which weprobably cannot even imagine at themoment. But bear in mind that something ofthis scale does not happen overnight; it took20-25 years for information from space to beused and be shown everyday on TV inweather forecasting.”

The FutureCoulson shares his thoughts about thefuture: “In my opinion, the true value ofEarth Observation will come into play whenthe modelling, assimilation and forecastingtechniques are fully developed. Take meteo-rology. People are not very interested inknowing what the weather is like at thatmoment - they can simply look out of thewindow. But when the forecast for tomorrowor the next few days is given, then peopledo get interested. The same goes for EarthObservation. When it becomes possible touse this information to understand and pre-dict the effect that humans are having andwill have on our planet, then people will getmore than interested. This all starts withGMES. The next decade is going to be themost exciting and challenging period in thefield of Earth Observation.”

Robin Wevers ([email protected]) is

a freelance writer of geo-ict-articles.

More information can be found at www.esa.int/eomd.

can do in the area of sustainable develop-ment with large corporate industries. This isa hot topic; big industries are very sensitivein being able to show that they can developtheir business without damaging the environ-ment. We are working very closely with largeinternational companies like Shell, SuezEnergy, Alcan and Lafarge group to demon-strate that EO information can help them outin monitoring and reporting their corporateactivities. Another area we are looking at iswhether EO can play a role in assessing theexposure risk for industries associated withclimate change. There is increasing pressurefrom leading investors, especially in the US,to enforce companies to analyse and dis-close how the consequences of climatechange could affect their assets and busi-nesses. These consequences include thingslike floods, droughts, storms, fires, rising sealevels and melting ice. Industry is becomingmore active here, an example being the'Climate Group' recently set up and lead bySwissRe in the UK.”

GMESAccording to Coulson Global Monitoring forEnvironment and Security (GMES) is thewake-up call for Earth Observation: “It is the


Interv iew

ted’ted’

Stephen Coulson's view on the future: "In my opinion, the true value of Earth Observation will come into playwhen the modelling, assimilation and forecasting techniques are fully developed".

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 25

Interview with Leading Manufa cQuestions on Future Market and DevelopmentsInterview with Leading Manufa c

In alphabetical order Hemispere, Leica Geosystems, Navcom Technology, NovAtel,

OmniSTAR, and Thales Navigation will provide answers to six questions mainly

related to the future. We hope this article will give you readers a clear overview of the

direction of these leading companies.

Please give an overview of your company and products.

Hemisphere: Hemisphere GPS (www.hemispheregps.com) was formed in April2005 as the GPS division of CSI Wireless Inc.;a 15-year-old company with customers in morethan 50 countries worldwide. Hemisphere pro-duces GPS and DGPS receivers and compo-nents, agricultural guidance systems forground and air applications, automated steer-ing systems, variable rate control products,heading and attitude solutions for navigationand mapping software. In addition to GPSreceiver products, they produce OEM receivercomponents, antennas and cables. The Hemisphere product line serves severalhigh-growth markets including precision guid-ance in agriculture (ground-based and aerial),commercial marine, industrial, and geographicmapping & survey. Hemisphere owns a signifi-

cant proportion of its own technology, andcontrols a growing list of registered and pending patents for the benefit of its world-wide customer base, including many originalequipment manufacturers (OEMs).

Leica Geosystems: Leica Geosystems’ productsand services (www.gi.leica-geosystems.com) areused by professionals worldwide to help themcapture, analyze, and present spatial informa-tion. Leica Geosystems is best known for itsarray of products that capture, model, analyze,ad visualize and present spatial information.The products that incorporate GNSS technologyinclude the Leica SmartRover, a cable free,lightweight solution fully compatible with LeicaSmartStation, with the new RTK GPS LeicaSmartRover designed for modern surveying.Another product is the Leica SmartStation withintegrated GNSS, that combines TPS and GPSin one instrument.

NavCom Technology: NavCom Technology,Inc. (www.navcomtech.com), a wholly ownedsubsidiary of Deere & Co., designs and man-ufactures precision GNSS positioning andwireless communication products for agricul-ture, survey, construction, machine automation, offshore and military applications. GNSShardware is supplemented by a commercialGlobal Satellite Based Augmentation Systemfor base-free precise point positioning.

NovAtel: NovAtel (www.novatel.com) is a publi-cally traded company that designs, marketsand sells high-precision GPS and other posi-tioning components and sub-systems used ina variety of commercial applications principallyin the aviation, geomatics (surveying and map-ping), mining, precision agriculture, marine anddefence industries. NovAtel is also the princi-pal supplier of reference receivers to nationalaviation ground networks in the US, Japan,Europe, China and India. Its solutions combinehardware, such as receivers and antennas,with software to enable its customers to fullyintegrate the company’s high-precision GPStechnology into their respective products andsystems. The newest OEMV family of engines deliversGNSS positioning and features such asGLONASS measurements, GPS modernization(L2C & L5), API, Vision Correlator capabilityand integrated L-band. They are also RoHScompliant. In conditions where GPS alone isless reliable, NovAtel has developed SPANTechnology - an inertial measurement unit(IMU) combined with an enclosure to providecontinuous positioning and attitude. To com-plement SPAN, NovAtel offers GPS+Inertialpost-processing software through its WaypointProducts Group.

OmniSTAR: OmniSTAR (www.omnistar.nl) provides commercial real-time satelliteDifferential GPS (DGPS) services and prod-ucts worldwide and is active in the designand development of DGPS positioning technology. The OmniSTAR services,OmniSTAR-VBS ('Virtual Base Station; sub-metre level) and OmniSTAR-HP ('HighPerformance'; decimetre level), have beenspecifically developed to satisfy the require-ment for high accuracy positioning systemsand services in land based applications.

June 200626

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NovAtel’s EuroPak-L1L5E5a receiver with GPS-704X antenna: 16 channel tracking of GPS L1/L5, Galileo L1/E5a and SBAS signals, in a Euro form-factor card, packaged in EuroPak enclosure.

NovAtel’s SPAN technology: a tightly-coupled integration of GPS

and an Inertial Measurement Unit toprovide continuous operation through

satellite outages with accurate posi-tion and attitude measurements.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 26

Thales Navigation: Thales Navigation(www.thalesnavigation.com) is a global innovator of positioning and navigation solutions. The company markets its profession-al GPS and GNSS solutions in the survey, GIS/Mapping, and OEM markets thatinclude consumer electronics, automotive navi-gation and high-precision applications. It markets its Magellan brand GPS products invehicle navigation and outdoor markets.For surveyors, Thales’ latest offerings includeZ -Max.Net and ProMark3. Z-Max.Net includesVRS, FKP, NTRIP and GPRS, RTCM V3.0 net-work communication. ProMark3 offers bothhardware and software needed to perform fastcentimeter accurate static, stop & go, andkinematic surveys, as well as GIS/mapping,right out of the box. Thales MobileMapper CEincludes real-time, sub-meter GPS positioning,embedded Microsoft Windows CE .NET,Bluetooth wireless technology, removable SDcard memory and an all-day removable battery.

How do you see the future market forGNSS related products in relation to yourcompany and its current products?

Hemisphere: Hemisphere’s core business isbased upon providing high precision GPSsolutions to its customers. As the GNSS sys-tem is expanded, we intend to take advan-tage likely through increasingly accurate solu-

NovAtel: NovAtel is currentlyfielding GPS/GLONASS andGPS/Galileo receivers. We areworking to deliver combinedGPS/GLONASS/Galileo receivers intime for Galileo operability andfor GLONASS constellationenhancement to full compliment.NovAtel is developing and mar-keting receivers as the new com-bined constellation systemscome on line and in addition,developing new combined prod-ucts available in time to capturethe full benefits of multiple con-stellations.

OmniSTAR: OmniSTAR as signalprovider has plans to add differ-ential GLONASS, and differentialGalileo. This will lead to higheraccuracy, greater availability and

faster convergence. The overall GNSS marketwill grow and OmniSTAR will keep focus onthe professional high-end users.

Thales Navigation: All GNSS markets continuegrowing at a very brisk pace. We estimatethat the GPS Survey market grew at justunder 20 per cent in 2005 and the GIS mar-ket around 10 per cent. We anticipate that themarket will continue to grow as GNSS pene-tration increases in the current segmentsusing GNSS as well as in emerging segments.Thales will continue to focus its productdevelop on solutions that meet the needs ofnew vertical markets that may not be takingfull advantage of GPS to date because of thecost and complexity of deploying and usingprofessional-grade GPS.

Both GPS and Galileo will introduce newsignals and new frequencies.Furthermore more satellites will be avail-able. What will be the benefit(s) of theseto future users of (precise) positioningsystems?

Hemisphere: Better accuracy due to multiplefrequencies and additional signals (moreranging information), longer baselines forRTK ambiguity resolution, more robust ambi-guity resolution, improvements in positioningin urban environments due to increased

tions and more availability of signals in tradi-tionally difficult reception areas. This will leadto more solutions for various applications innon-traditional areas. These would includebetter solutions at lower costs to farmers,construction companies, mariners and survey-ors alike.

Leica Geosystems: Leica Geosystems designsand develops GNSS products used for precisepositioning for Surveying, Machine Automation,Reference Station Networks and GIS data col-lection. With the increased number of satellitesprovided by GNSS our customers will benefitfrom increased productivity and improvedaccuracy and robustness of the solution. LeicaGeosystems GNSS products are ‘future proof’and designed to support future GNSS signals.

NavCom Technology: Accuracy is addictive;more users are appreciating the benefit ofpositioning accurately the first time. Therewill be increasing use of real-time preciseaugmentation services to remove the needto deploy a temporary local base station.Equipment will continue to decrease in sizeand cost while offering more features,greater integration with other sensors andsimplifying use. We believe NavCom andJohn Deere are well positioned to benefitfrom these trends especially for autonomousand guidance assisted vehicles.


Specia l

a cturers of Positioning Productsa cturers of Positioning Products

The Leica SmartRover, a cable free, lightweight solution fully compatible with Leica SmartStation.

The Leica SmartStation with integrated GNSS, that combines TPS andGPS in one instrument.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 27

deployment. GNSS users can look forward to better per-formance in terms of signal availability, fasterambiguity resolution and longer baselines asmore signals become available. Thales isactively working to optimally integrate all ofthese signals in future products. However, itmust be kept in mind that the GPS receiversbeing used today will continue to operate atthe same high level of performance in thefuture, L1 and L2 P/Y will continue to betransmitted just as before. It should also benoted that the deployment of the new sig-nals will take time, the estimated timelinesare as follows:• A full GLONASS constellation will proba-

bly not be in place until 2009;• Galileo will probably not be fully

deployed until 2011; • L2C will not be fully deployed until the

2nd half of 2013; • L5 will not be fully deployed until after

2014.

Do you see WAAS/EGNOS in combinationwith the paid-for Galileo commercial service as a replacement for regularDGPS services?

Hemisphere: No, the paid services will prob-ably not survive since excellent accuracieswill be available free of charge. OmniSTARmay be hurt somewhat by this (they mayneed to carve our new niches), but alreadyWAAS solves many accuracy requirementsusing free signals.

Leica Geosystems: Currently it is not clearhow the commercial Galileo service will bestructured. To provide customer value thecommercial Galileo service will need to

constellation of combined GNSS systems,improved signals that will improve indoorand weak signal positioning. There will alsobe more robust signal tracking at multiplefrequencies (as opposed to marginal P(Y)code tracking) allowing higher dynamics andweaker signal tracking. Better estimation inatmospheric effects due to increased obser-vations will also be possible, thus furtherimproving accuracy.

Leica Geosystems: An increased number ofavailable satellites, signal and frequenciesprovided by an ever expanding GNSS willallow errors to be more accurately modelled,positioning to be more accurate and therobustness of the solution to be furtherimproved. Ultimately, users will be increas-ingly more productive and work in areaswhere this was impossible with GPS only.

NavCom Technology: Currently, GlobalSatellite Based Augmentation Systems canachieve sub-decimetre positioning accuracyfor GPS dual frequency receivers.Supplement this with local base stations,and accuracies of a few centimetres are pos-sible, even a few millimetres when post pro-cessed. The future new signals and satelliteswill not significantly improve upon theseaccuracies but should provide more redun-dancy, integrity and robustness.

NovAtel: The Galileo services are generallycompatible with existing GPS services. Theexpectation is that users will demand theadded reliability, integrity, and functionalitythat a combined GPS and Galileo receiverwill provide when used together. To a user ofa receiver with both systems, the primaryadvantage is twice as many satellites provid-

ing twice the probability of receiving goodsignals from good parts of the sky when vis-ibility is reduced or blocked. Vehicles in urban environments will see moresignals, more often and suffer less from sig-nal blockage. Surveyors will have higheraccuracy measurements, more consistently.Automated guidance for agricultural sprayers,combines and harvesters will be more accu-rate and signal reception will be improved,reducing signal outages. Difficult inshorenavigation on rivers and canals will be saferand more reliable. Aircraft enroute naviga-tion, final approach and landing will have fargreater signal redundancy, which could wellresult in improved safety margins andreduced decision heights for landing. Thenew GPS frequencies will provide compatibleservices to those of Galileo, but without userfees. The main benefits will be less complex,more cost effective dual frequency receivers.However the actual number of GPS satellitesis not forecast to increase, so the dual con-stellation benefits above will be limited touse of the combined GPS and Galileo con-stellations

OmniSTAR: L2C delivers better L2 PseudoRange accuracy. The GPS L5 third frequencywill lead to shortened convergence timesand will allow more work in Urban canyonenvironments.

Thales Navigation: The high value and utilityof real-time access to accurate positioninghas been proven by the initial implementa-tion of GPS. It is a testament to this that theUS is now embarking on a significant mod-ernization of the GPS system, that Russiahas set a goal to fully deploy GLONASS by2008 and that Galileo is in its early stage of


OmniSTAR Backpack. Applying OmniSTAR technology, by courtesy of the Agco group, Ltd.

Specia l

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 29

deliver accuracy equiva-lent to current DGPS serviceswithout the initialisation times that are oftenrequired to provide decimetre solutions. Ifdecimetre level positioning could be providedin less than a minute, rather than 10 minutesas needed today, then this truely representsa customer benefit and would justify a ser-vice fee. Although this service would be of lit-tle benefit for surveying, decimetre position-ing is adequate for many GIS, hydrographicand agriculture applications.

NavCom Technology: The cost of a Galileocommercial service will deter adoption bythose users currently using free BeaconDGPS, WAAS or EGNOS. For users who needgreater accuracy, commercial DGPS, RTK andGSBAS services are already very cost compet-itive. The Galileo commercial service will haveto compete against these and potentially anaugmentation service on Glonass.

NovAtel: NovAtel has a number of land andmarine customers using WAAS/EGNOS aug-mented receivers. WAAS does not currentlyhave full redundancy, with pretty low eleva-tion GEO’s, so signal blockage can be a prob-lem. New WAAS GEO’s coming on line in2007 will be more central over the US, soblockage will be much less of a problem.EGNOS, although successful last year inachieving operational readiness, is still some-times operating intermittently - so full timecommercial operations are not 100 percentreliable. This will improve as the EGNOSmatures. Both WAAS and EGNOS when fullyreliable almost provide full DGPS capabilityfor users with good GEO visibility. If we nowadd another full constellation of Galileo satel-lites, signal reliability will significantlyimprove for dual-mode GPS/Galileo receiverusers. But accuracy doesn’t get much bettersuddenly. To do that the EGNOS and WAASsystems need to be upgraded to add Galileosignal monitoring and integrity verification. Atthat point, the GEO signals may well improveaccuracy significantly – for example, two foldbetter than the current 1-2m provided.

OmniSTAR: The primary objec-tive of EGNOS is delivering

integrity and not accuracy. The accuracylevel will probably remain at the 1-2 meterrange in order to achieve the integrity levelof 99.999%. There will remain a market forhigher accuracy DGPS services.

Thales Navigation: No, at least not in theshort term. WAAS and EGNOS will notreplace ground based DGPS services becausethere will always be signal environmentswhere the geo-stationary satellites transmit-ting the WAAS and EGNOS corrections willnot be visible. The open question is whetherthe paid-for Galileo commercial service willdeliver accuracies equivalent to what can beattained with DGPS today, there is good like-lihood that it will.

The Volpe and Helios study both showedthat we should not depend too much onGNSS as a sole means of navigation. Inthis respect, how do you see the devel-opment of three similar GNSS systems(GPS, GLONASS and Galileo) and the dis-continuation of the Northwest EuropeanLoran System (NELS) agreement?

Hemisphere: No problems, we believe GNSScan become a sole means of navigation.

Leica Geosystems: Loran systems are purenavigation systems and were originallydesigned for marine applications. Satellitebased navigation systems have the clearadvantage that they do not require the localground-based infrastructure. Furthermore,Loran system could never offer global cover-age due to the lack of ground-based stations, and the delivered accuracy wasoften inadequate. With independent GNSSsystems, it is possible to deliver indepen-dent solutions that offer true integrity moni-toring for applications that demand a highlevel of redundancy.

NavCom Technology: Modern transportationis truly global. GPS, GLONASS and Galileoaddress this need whereas the regional NELSdid not. The three GNSS systems both com-plement and backup each other but theirinherent weakness is their similar system.

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Hemisphere Vector GPS Compassfor Marine and Industrial appli-cations.

Hemisphere Outback S2 GPS GuidanceSystem for agriculture applications.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 30

NovAtel: The key will be to bring all three sys-tems into internationally recognised opera-tional standards so all users can be sure ofthe level of signal integrity which is availablefrom each system and from the combined useof all systems. The idea has already beenfloated to add Galileo capability to WAAS andthe initial Galileo reference receivers for theground control system contain dual frequencyGPS receivers. Work has already begun to for-mulate Galileo Standard and RecommendedPractices (SARPS) within ICAO and tentativesteps are being made towards a combinedGPS/Galileo operational requirement. These ini-tiatives will of course take time – neither theGalileo nor the GLONASS constellations are yetfully deployed – so standards will be devel-oped over the next several years. Back-upLoran systems will likely be required for sometime to come.

OmniSTAR: As NELS had insufficient user inter-est its discontinuation came as no surprise tous. If the need for independent means of navi-gation is strong we, the private sector, will ful-fil these requirements.

Thales Navigation: All navigation systems areto some degree susceptible to errors; it is forthis reason that navigators never rely on justone system. A ship may use GNSS as the pri-mary navigation but will typically also haveINS, radar and if all else fails visual navigationusing sextants, a compass and charts can beused. It is true that scenarios can be envi-sioned in which GNSS canfail but the probability ofthis happening is extremely

satellite technology. To improve positioning reliability in these envi-ronments, the stable measurements from anInertial Measurement Unit (IMU) are correctedfor drift and combined with the GPS solutionand/or the raw phase and pseudorange GPSobservations to produce a tightly-coupledsolution. When satellite signal outages occur,an integrated GPS/INS system will use the rawIMU data to compute a solution through theoutage. These complementary technologiescreate a system with accurate position, veloci-ty, and attitude output that provides continu-ous positioning in challenging GPS environ-ments. NovAtel’s Synchronized PositionAttitude Navigation (SPANTM) technology pro-vides these features by combining NovAtelGPS receivers with selected inertial measure-ment units.

OmniSTAR: We are confident that develop-ments with relative inexpensive MEMS willcontinue and will solve outages up to 1minute at the sub meter level. Longer andmore accurate INS will remain the field of theprofessional users.

Thales Navigation: GNSS has delivered to theworld a global navigation system, the cover-age of which being far greater than any othernavigation system ever deployed. For loweraccuracy consumer applications technologiessuch as A-GPS and dead-reckoning are able toprovide positioning in GNSS black-out spots.For high accuracy underground positioningapplications such as tunnel surveying opticalsurveying technology will continue to be used.

More information on:

WAAS: http://gps.faa.gov/Programs/WAAS/waas.htm

EGNOS: http://www.esa.int/esaNA/egnos.html

Volpe: www.navcen.uscg.gov

Helios: http://europa.eu.int/comm/dgs/

energy_transport/galileo/documents/technical_en.htm

NELS agreement: www.nels.org

low, especially with the emergenceof three independent systems;GPS, GLONASS and Galileo. Anexternal factor that could affect allthree systems concurrently wouldbe an extreme magnetic stormcaused by solar flares. However, inits 30 years of operation there hasbeen no major effect from solarflares on GPS navigation. It shouldalso be noted that such events areusually predicted considerablyahead of time.Finally it must be understood thatthe integrity and reliability of GNSSis substantially higher than LORAN.As a system, LORAN is susceptible to a num-ber of external factors such as electrical distur-bances like lightning and even topography.

There are still circumstances in whichGNSS does not work properly. Do yousee developments in the nearby futurethat will counter current GNSS black-outspots such as indoor, tunnels and thelike?

Hemisphere: Improvements in signal structureand the addition of new satellites and signalswill help here, but there will always be situa-tions where reception problems can occur.

Leica Geosystems: GNSS alone cannot solveall positioning tasks. Today total stations areused together with GNSS to provide a com-plete positioning solution for surveyors. Manyresearch projects around the world are inves-

tigating sensor combinations to provide cm-positioning everywhere. One approach is tointegrate GNSS with inertial sensors, othersinclude the integration of laser distance metersand CCD-cameras. Solutions are available forniche markets, however, the cost andsize/weight of these systems make their wide-spread use for high accuracy applications limit-ed. The breakthrough for high-accuracy wide-spread use is yet to be discovered!

NavCom Technology: Augmentation of GNSSvia additional sensors and services will literallydrive the future. Having a global ground basedalternative to GNSS is desirable but willrequire international cooperation and stan-dards to leverage ground based wirelessinfrastructure as an alternative to GNSS.

NovAtel: Short outages are common in manyreal world applications especially throughoutthe ‘urban canyons’ found in the downtown

area of larger cities as well as in forestedareas. Working in these conditions results inreduced productivity when relying solely on

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Z-Max.Net includes standard VRS, FKPand NTRIP network communication(Thales Navigation).

ProMark3 builds on the tradition of the ProMark2 from ThalesNavigation.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 31

First Nationwide High-density GPS Geographic Expansion PossibleFirst Nationwide High-density GPS

In October 2005 LNR Globalcom presented its nationwide GPS RTK network under the

name GlobalNET 2005. This article describes the origin and history of the network, the

technique used for the network calculations and the advantages for the users of the

network.

By Marnix van der Wolk

HistorySince the implementation of the GlobalPositioning System (GPS) in the early 1990’s,land surveying with centimeter-level accuracyhas been possible, using the post-processingtechnique. In 1998 a new technique, GPSRTK (Real Time Kinematic) became opera-tional, making real-time centimeter accuracyat the GPS receiver in the field the new reali-ty. In keeping with the developments in theGPS technique, LNR Globalcom developedvarious software programs between theyears 1994 and 1996. There is GlobalREFsoftware to direct the reference stations, andGlobalCALL software for the automatic hourlydownload of the data from the reference sta-tions. GlobalBASE is the database programin the server and the Globalcom programallows the user to download the RINEX datafrom the reference stations into his ownoffice computer.The LNR Globalcom system and the ActiveGPS Reference System – for research andcertification purposes (AGRS) were bothintroduced in June 1996. As of that time thefirst 5 GPS reference stations in LNRGlobalcom’s network were operational.

GPS RTKIn 1998 a new GPS technique was introduced:Real Time Kinematic GPS (RTK). Using GPSRTK the user in the field is able to achievecentimeter accuracy. Post processing wassteadily being replaced by RTK GPS. To facili-tate this trend, starting in 1998, the GlobalNETreference stations began sending correctionsout via radio connections, and six monthslater also via GSM connections. The majoradvantage of GSM connections over radio con-nections is the greater reach.Alongside this inevitable technical develop-ment, the number of GlobalNET reference sta-tions steadily increased. This growth wasalways project-related. At the start of 2005 six-teen GlobalNET reference stations existed inthe western part of the Netherlands. These ref-erence stations sent local RTK corrections viaradio and GSM connections, and the RINEXdata was continuously being saved. The cor-rections were being sent via the receiver inindependent RTCM format, thus all receivertypes were being supported.

GlobalGSM ProgramTo allow several users simultaneous access to the corrections from the same reference

station, LNR Globalcom developed a so-calledGSM box, see Figure 1. The GlobalGSM pro-gram made it possible to authorize GSM (cellphone) numbers contained on the SIM cardsin the modems. Since the user was able toplace his own SIM card in the station, costsaving was achieved. In this manner, the userwas able to call under the auspices of hiscompany’s telephone subscription and utilizethe lowest available rate. Since the RTK correc-tions are sent directly from the receivers, aninitialization time of less than 10 seconds canbe guaranteed. Additionally, a high degree of reliability is alsoachieved. However, this solution is only appli-cable for users located close to the referencestation. In order to provide RTK corrections tousers, located further away from the referencestation, with at least this same high degree ofaccuracy, GlobalNET has been expanded toinclude 41 reference stations and uses a net-work solution. With the help of SpiderNETsoftware from Leica Geosystems, all the sta-tions are connected to one another to offer anationwide network solution to the users.

TechniqueThe 41 reference stations are not more than50 kilometers apart. The western part ofHolland still contains a higher concentration ofreference stations, due to the fact that thehighest concentration of users is (still) withinthis area. In order to achieve complete cover-age also along the border areas, a few refer-ence stations from the Belgian FLEPOS net-work and the German SAPOS network are alsoincorporated within GlobalNET.The heart of GlobalNET can be found inRijswijk, the Netherlands, where the mainservers are located. These servers are in con-tinuous contact with the reference stations. Allthe raw data is available in a split second viaADSL lines. The raw observations are saved asRINEX data and are also used for sending theRTK corrections to the user in the field.Alongside corrections for RTK receivers (cen-timeter accuracy), dGPS corrections are alsooffered for users with GIS receivers (sub meteraccuracy) and for shipping vessel navigationpurposes.The quality of the data from the reference sta-tions is also being continuously monitored. Inthis manner, each station is being verified forthe completeness of the data, the degree of

June 200632

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Figure 1, the GSM box.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 32

multi-path, the signal/static ratio and the num-ber of cycle slips. Thus, the quality of the dataused can be continuously controlled.

Three ClustersThe total of the 41 reference stations will here-after be referred to as the network. The net-work is divided into three clusters, a clusterbeing a sub-network within the full network ofreference stations. Generally speaking,GlobalNET is divided into one cluster for thenorthern part of the country and one clusterfor the southern part of the country. For themost part, these two clusters overlap oneanother. As a back-up for these two clusters, anationwide cluster has been established con-taining a selection of the reference stationsapproximately seventy kilometers apart.The ambiguities to the available satellites aredetermined within each cluster by the Spidersoftware, using the LAMBDA method whichwas originally developed by the TechnicalUniversity of Delft. This method is used foraccurate positioning, calculating the totalamount of wave lengths between the GPSreceiver and the satellite. The total number ofwave lengths is determined by means of a‘smallest quadrants’ estimation. This methodappears to be quite accurate since additionalmistakes are minimalized. Consequently, a collective ambiguity level for aparticular cluster can be calculated. Each clus-ter can be subsequently divided into an unlim-ited number of cells. The RTK corrections aresent via these cells to the user in the field. A

StandardIn order to receive all the data every second,a new data format has been developed:RTCM version 3. RTCM is an internationallyaccepted standard for the exchange of GPSdata, which is supported by all GPS receiverbrands. This new RTCM v3 data format hasbeen specially designed for the transmissionof corrections from multiple reference sta-tions. To allow as many users as possible accessto the network at the lowest cost, the vari-ous corrections are sent over the Internet viaNetworked Transport of RTCM via InternetProtocol (NTRIP). This can be compared toInternet radio. The Internet connection to theuser in the field is achieved via a GSM (cell)phone with a SIM card supplemented with aGPRS subscription. This technique ensuresthe mobile connection to the Internet, aslong as the mobile (cell) telephone networkis available in the area.

FutureIn the future the network will continually beupdated to accommodate the latest availabletechnologies, such as the implementation ofextra satellite signals; for example L2C, L5and the European system Galileo. The net-work can also be expanded geographically,to provide service to international customersas well.

Marnix van der Wolk

([email protected]) is sales engineer

with LNR Globalcom. More on this company via

www.lnrglobalcom.com.

cell can have a permanent shape or can beautomatically determined by the network.

Six VariationsThe available RTK corrections are available assix variations:• Fixed reference station;• Closest reference station;• Fixed cell (using I-Max);• Fixed cell (using Max);• Automatic cell (using I-Max);• Automatic cell (using Max).

Fixed reference stationThis solution can be more or less compared toone’s own reference station. This solution isappropriate for a client wanting to continuous-ly use the same reference station.

Closest reference stationWith this variation the user does not need toselect the reference station from which toreceive the corrections. As soon as the user inthe field logs on into the GlobalNET server, theclosest reference station, (based on the user’sposition) will automatically be determined. Thecorrections from this closest reference stationwill be sent to the user.

Fixed cellTogether with the user, a specific cell of ref-erence stations is predetermined. When log-ging in the user can select either the I-Maxsolution or the Max solution. Within the cell,,see Figure 2, one of the reference stations isdesignated as the ‘master’; normally this isthe most centrally located station. For rovers,which are not yet equipped for the Max solu-tion, the I-Max solution has been developed.In addition, the data can later be relatedback to the reference stations; thus, an extraquality check based on the raw data isalways possible. This product is most appropriate for userswith a permanently-defined work area.

Automatic cellIn terms of technique and network calcula-tions, this variation, see Figure 3, is compa-rable to the fixed cell. The major difference isthat the cell is not pre-determined. Thisvariation is recommended for users whosework area frequently changes.


Specia l

RTK Network in the Netherlands RTK Network in the Netherlands

Figure 2, fixed cell.

Figure 3, automatic cell.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 33


‘Galileo All About Ambitionand Political Willingness’Interview with Peter Grognard, Director of Septentrio

‘Galileo All About Ambitionand Political Willingness’

Stations capable of receiving GPS, GLONASS and/or Galileo are steadily entering the

market, and high above our heads more and more satellites are coming into orbit. All

because highly accurate positioning data are essential, and because of the numerous

possibilities of three satellite systems. Sceptics wonder if we need a third system, and

if Galileo is worth the expenses. GeoInformatics had an interview on these and other

topics with Peter Grognard, director of Septentrio, a young and successful Belgian

company with a firm belief in Galileo.

By Sonja de Bruijn

IntegrationNow that there will be three systems in2010/11, the American system GPS, theRussian system Glonass and the EuropeanGalileo, integration is the first topic of dis-cussion at the Septentrio office in Leuven,Belgium. Does Grognard think we are movingtowards an integration of the systems? “Yes

and no. Clearly there will be combinedreceivers capable of getting all types of sig-nals, for both professional and private users.Especially this last type of user will not beaware of the fact that combined signals areentering his receiver.”When looking at system level there seems tobe integration to the extent that agreementshave been reached especially with the USJune 2004 on standards regarding interoper-ability and compatibility. Exception is theGPS military signal which falls under theresponsibility of the US government, as wellas the European Public Related Service (PRS)which is a European-only aspect of theGalileo program. “We are working on thesame kinds of agreements with Russiabecause these agreements obviously have animpact on trade and technical develop-ments”, says the director. Just to make clear:integration of the satellite systems them-selves will not take place: these will transmittheir own unique signals. How does Grognard feel about the involve-ment of China in Galileo? “It is my belief thatcertain parts of Galileo should not be sharedwith any non-European country. Furthermoreit is my opinion that a third party like Chinashould only get involved if they can actuallycontribute to Galileo by means of openingup the market, cooperatively developingapplications, or bringing in technologicalexpertise. In its turn Galileo can make arobust contribution by covering local compo-nents that up till now are not covered inChina.”

AttitudeThe attitude towards Galileo has changeddrastically over the past five years. Firstthere was scepticism, not only in the US butalso in Europe. ‘Galileo will never work’, and‘Why do we need this system when there isGPS?’ were commonly heard phrases.Furthermore security was a concern: whatwould be the impact of a new system onmilitary operations? But now that the firstsatellite is up and running and receivers arebeing built that can receive Galileo signals

Specia l

Peter Grognard, Founder andManaging Director of Septentrio.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 35

June 200636

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progressed there is more belief. Grognard:“The fact is that more satellites are neededand GPS and Galileo can complement oneanother perfectly. This is not to say thatthere is no negative talk about Galileo any-more. One should not forget that GPS hasexisted for thirty years now, with the firstplans appearing in 1960. The expertsinvolved in this are still very influential.However the world is changing, and so aresatellite systems.”

GlonassClearly GPS is quite important with respect tothe new satellite system, but what areGrognard’s thoughts about the Russian equiva-lent? “GLONASS is coming into the pictureagain since the Russian government has gotplans to rebuild the system. Every year aroundChristmas three satellites are launched andthere is more and more demand for receiversthat can deal with combined signals. When westarted Septentrio in the year 2000 we devel-oped a combined GPS-GLONASS receiver withwhich we were able to receive signals of morethan 20 satellites during the time these sys-tems were connected, a phenomenal accuracy

that could never be achieved with just onesystem. For us this was a clear sign of whatGalileo could bring in future.”Grognard admits GPS is more important tohim than GLONASS for technical and program-matic reasons. “First of all GPS satellites havean extremely long life cycle, in contrary to theGLONASS satellites. Next to this the US exper-tise in electronics and in operating the systemare reasons for me to regard GPS as a veryrobust system.” However, Russia has a tremen-dous experience in space system and I amconfident that with a little luck, Russia willmake GLONASS fully operational again.

Search & RescueWhat extras will Galileo offer in comparisonto GPS? “Information on the integrity of thesignal will be delivered with the signal so auser knows he can rely on his position. Thenthere is ‘Search & Rescue’, which makes anaccurate positioning of people in need possi-ble. Instead of having to combine differentsignals with several receivers all this is nowcombined. So we are utilizing the strength ofGPS and improving what needs to be better.”Though prices for these extra Galileo services

are not known yet, these will have to belower than those of existing providers.Grognard is not really informed on this butdoes share the opinion that existing serviceproviders offering commercial services shouldnot be put aside. “Besides having a goodposition in the market they also have thetechnical know-how so this will make it hardbut moreover unwise to push them out ofthe market.”

Negative AdviceGrognard’s reaction to the statement ‘Galileomeans a lot of expenses for an extra systemthat we don’t really need’ is fierce. “First letme say that at the end of the nineties sever-al EU member states gave a negative adviceregarding Galileo. This was due to bad infor-mation provision by their own industries,because of political reasons or due to igno-rance. An example is Germany where theautomobile industry stated it didn’t needGalileo. Although this industry now realizesthe importance of the new system, the badtone had been set. This movement has cre-ated the feeling that Galileo is an expensivesystem that Europe does not really need.”

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 36

June 2006Latest News? Visit www.geoinformatics.com

“Now let’s have a closer look at the expens-es. The total costs of Galileo are € 4 billion.There are 450 billion European citizens atthe moment. Projects started in 2002 andGalileo will be operational in 2010/11. Thismeans 8-9 years of development and tests,which boils down to € 1 per year perEuropean citizen. To compare: a Europeancitizen yearly has to pay roughly 100 euroson agriculture. If we want to be the mostimportant economy in the world, we need totake action instead of sitting and waiting forthe US and Japan to come up with newinnovations. So it is not about costs butabout ambition and political willingness.” Hecontinues: “Concerning the costs of the com-bined receivers: prices may go up a bit, buta manufacturer needs to regularly update itshardware and software anyway. A combinedreceiver simply is a modernization that hasto be done.”

InterferenceThe advent of Galileo won’t really make adifference in the vulnerability of each sepa-rate system. Grognard: “Interference is apotential threat. The signals are weak andquite easy to jam on purpose. However the

system is distributed in such a way that it isimpossible to disturb all receivers simultane-ously. Still Septentrio and other manufactur-ers are working on techniques to makereceivers less sensitive.”Especially in aviation (safety reasons) or insegments where GPS is used for the automa-tion of certain processes this is crucial.Higher frequencies are hardly possiblebecause of the insufficient power of thesatellites and certain rules laid down in inter-national agreements regarding the frequen-cies that are allowed. “The solution lies incombining the systems that are transmittingsignals at different frequencies and makingthe receivers less vulnerable”, says Grognard.

Positive DynamicsAccording to Grognard Galileo definitely hascreated a lot of positive momentum andattention. “But we have to make a lot ofeffort to make use of satellite systems in aneconomical way like the US and Japanalready do. Possibilities are only limited bypeople’s imagination. And there is a hugegrowth potential, especially in the automo-bile industry and the consumer marketspace. Currently the GPS market is worth

about $ 12 biljon which is relatively small.”Grognard also mentions quality in agricultureand stricter worldwide regulations in ship-ping which will cause these markets to grow.“Especially in shipping where mistakes occurquite easily which makes accurate determina-tion of your position important.” Grognard stresses the importance of a prop-er maintenance of the Galileo satellite sys-tem and a simple and transparent institu-tional framework, similar to the United Statesframework. Grognard: “Possible bottleneckscan be too many regulations for use anduser fees not agreed on by manufacturers innon-European countries that do apply tomanufacturers in Europe. This is why a sim-ple and transparent framework like I justmentioned is crucial.”



Visit www.septentrio.com to learn more about this

Belgian company.

37

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The PolaRx2e, versatile dual-frequency GNSS receiver developed by Septentrio.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 37

Review Trimble R8 GNSS versus TGPS and Glonass combined receiversReview Trimble R8 GNSS versus

The adage ‘more is better’ is heard everywhere nowadays, replacing quality with quantity. In the past a land surveyor carefully

surveyed a few points per day. Every point was checked, double-checked and then again, since errors made in the field had to be

corrected by hand. With the advent of RTK GPS a multitude of points can be taken in only a short amount of time. However this

quantity must go together with quality or a complete survey can be thrown away. Over the next decade or so, we will see the rise

of yet another GNSS system that, on paper should add to the quality and speed of our measurements. But are more satellites really

better? GeoInformatics tested two RTK systems with the possibility to receive both GLONASS and GPS satellites: the Trimble R8

GNSS (R8) and the Topcon HiPer Pro (HiPer). En passant we tried to find out whether more satellites can really improve survey

quality and speed.

By Huibert-Jan Lekkerkerk

RTK modeIn this article I will review both systems bycomparing them to each other in a realworld situation. I tested the systems in rela-tive RTK mode whereby I measured all roverpositions from an estimated base position.Both sets consisted of:• Rover and base station;• Survey controller;• Tripod and mounting bracket for base;• Survey rod and mounting bracket for sur-

vey controller;• Battery loader;• Various cables and software.

Trimble R8 GNSSThe R8 was the first to arrive at the test site,kindly provided by GeoMETIUS, the DutchTrimble representative. After a brief instruc-tion, it was time for my own tests. The sethad been taken care of by GeoMETIUS andas such was in working condition. Since theyuse it for demonstration purposes, I waskindly requested not to alter the preconfig-ured settings. Since these worked alright, Itook these as a starting point for the review.

Topcon HiPer ProThe HiPer Pro was the second to arrive. Asbefore, the representative from Topcon EuropePositioning gave a brief instruction. Accordingto Topcon, the HiPer Pro lent to us camedirectly off the shelf. However, base, rover andsurvey controller were pre-configured in sucha way that they were ready to go. This time Iwas not asked not to change any settings butstill decided to leave them as they were.

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Receiver particulars as specified by manufacturer.

Complete Trimble R8 GNSS set as reviewed.

Prod_GEO_4_2006 30-05-2006 15:21 Pagina 38

InstallationAs mentioned, both sets were pre-config-ured, and were instantly ready for operation.Since I used my own desktop computer forprocessing, I still needed to install the pro-cessing and data transfer software. Both sur-vey controllers operate under the mobileWindows operating system and needMicrosoft ActiveSync synchronisation soft-ware for data transfer.The Topcon FC-100 was easy to hook up anddata could be transferred without a glitch.With the Trimble TSC2 I had slightly moredifficulty. This was however quickly resolvedby a phone call to the support departmentof GeoMETIUS. The CD-Rom that was deliv-ered with the set was not part of a regulardelivery, but put together for the purposeand it seemed that it contained an incorrectsoftware version in this case. After down-loading and installing the correct versionfrom the Microsoft website, the problem wassolved.

Rover and Base Set-upWith the software and hardware up and run-ning it was time to unpack the cases andinstall the base and rover stations. Installingthe stations is easy enough without the needto connect any cables. Both sets useBluetooth communication between the receiv-er and the survey controller.Now let us have a look at the receivers. Ofcourse beauty is in the eye of the beholderand should not be important with utilitarianproducts like this, but personally I think theR8 looks rather pretty when compared to theHiPer. The neat design however comes at aprice since the transmit antenna and connec-tion ports of the R8 are placed at the bottomof the receiver. Due to this awkward location,an extension pole is needed when mountingthe set onto the tripod bracket. The HiPer looks like a standard receiver withan antenna put on top of it, but has theadvantage of having the transmit antenna ontop of the GPS antenna and all the connec-tion ports on the front side. The testedreceiver did not have any covers for theports, which could possibly result in damageto the ports from dust and rain when usedfor longer periods of time. The ports on theR8 all have plugs to cover the ports.The two R8 receivers were identical and rover

a single battery charge, the R8 needs freshbatteries halfway through the day. Both setscan however be powered by an externalpower source, which, according toGeoMETIUS, can, in case of the R8, providepower for up to 12 hours in transmittingmode. However this battery was not includ-ed in the test set.

PreparationOnce the base and rover were set up, it wastime to prepare the survey. Since I was goingto imitate a real survey, I had the base setup over a mocked-up benchmark. Both tri-

and base could be swapped without a prob-lem. With the HiPer set that I reviewed therewas a separate base and rover receiver.

PowerTo ensure I would not run out of power dur-ing my survey I wanted to start off with afresh set of batteries. With the R8 this sim-ply meant opening the battery cover andreplacing the battery with a fresh one. TheHiPer does not have this option and needsto be connected to the power supply. On paper the R8 has the advantage, butwhile the HiPer can survey for a full day on


Specia l

s Topcon HiPer Pros Topcon HiPer Pro

Complete Topcon HiPer Pro set as reviewed.

Prod_GEO_4_2006 30-05-2006 15:21 Pagina 39

pod brackets could be easily levelled andcentred over the benchmark. The R8 uses alaser pointer for centring while the HiPer butan optical plumb. Both worked perfect andhave their own disadvantages. The laserpointer is hard to read in bright sunlight andeventually will run out of power while theoptical plumb is hard to read with the receiv-er at a high mounting position.

Starting the BaseAfter centring the base antenna, I needed toenter both the benchmark coordinates andantenna height into the base. Both sets usethe survey controller for entering data intoeither base or rover. The survey controller com-municates with the base using Bluetooth andno cable switching is required. Since I did not

have an actual benchmark, I decided to usethe position as derived from the GPS coordi-nates of the base. Both receivers have thechoice to either take a single base position oraverage a number of readings to a single posi-tion. Personally I prefer the latter, but to behonest, this is a situation that a surveyorshould always try to avoid. During a normalsurvey I would either have the benchmarkcoordinates from the national survey or woulduse another RTK network for obtaining mybase position. As with a regular survey, I measured the anten-na height using a tape measure. The HiPer onlyhas two reference points marked at the sameheight at either side of the receiver from whicheither the direct height or slant range can bemeasured. The R8 has the option to measure

the height from a number of reference pointsat different (height) locations on the antenna,making it more flexible in the field, but at thesame time also introducing an additionalpotential error source.

Starting the RoverWith the base started, I had to switch the con-troller from the base to the rover. Switching isdone manually on the controller and somehowit seems that this should be easier. It seemseasier to tell the system once which receiver isused as base and which as rover and have thesoftware do the rest. But apart from this ‘wish’the switching was easy enough until theBluetooth connection on the Topcon controllerfroze up. A complete reset of the controllerand re-establishing the Bluetooth connectionto both base and rover was necessary beforeeverything was back to normal. Starting a survey is easy enough on both setsas it was just a matter of selecting the type ofsurvey. I tested two RTK modes: the singlepoint mode and continuous mode. Both setswork similarly for the single point mode; sim-ply enter the point code and start measuring.The continuous mode survey is different; theHiPer can collect data points every x meters orevery y seconds, while the R8 can combineboth.

SurveySince it was technical weather and my wifewas already brooding on jobs for me to do,I found it absolutely necessary to perform asmall-scale survey of my backyard. The reasonfor using my own backyard? It is close by andhas all kinds of real world problems whereadditional satellites are needed, since a house,a garden shed, trees and hedges are blockingthe receiver’s view of the sky.With both rover and base set up and started Iwent on to perform the survey. After eachmeasured point the survey controller automati-cally increases the point number so all theuser has to do is centre the antenna and starta measurement.One thing I noticed, not having used a landsurvey GPS set for a couple of years, was thedifference in operation between these sets andthe ‘older’ backpack style survey sets I used towork with. After a while I found out that theweight of the antenna on top of the relativelylong pole made the entire survey system top-heavy and relatively hard to hold steady dur-ing measurement. This used to be easier withonly an antenna on the end of the pole andthe receiver stored in the backpack. But thenagain, a backpack has its own disadvantagessuch as not that much freedom to movearound in tight places and the inability todirectly view the receiver status.

June 200640

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R8 base station and survey controller TSC2.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 40

Additional SatellitesDuring the survey some points had to be mea-sured that were partially shielded. Since thesurvey with the R8 took place on another dayand time as the HiPer survey, different satel-lites were available. With the R8 survey ‘only’7 GPS and 2 Glonass satellites were available,while during the HiPer survey there were 8GPS and 6 Glonass satellites. When measuringnear tops of hedges and under sparselyleaved trees the additional satellites seemedto make the difference. With few(er) satellitesthe receiver would regularly complain abouthigh DOP values and stop measuring in thesesituations. When measuring close to the house however,no matter how many satellites were visible,neither receiver could get a good fix. This isquite normal since the house shielded almosthalf of the horizon. Based on these few testsone could conclude that having additionalsatellites is no help under circumstanceswhere a large part of the horizon is shielded.This however is nothing new to the well-expe-rienced surveyor, since such a large blockingof the horizon causes a degradation of thestrength of the satellite constellation. It ishowever an advantage in those situationswhere there are relatively few satellites andexactly that part of the horizon is shieldedwhere a crucial satellite is located. In thesecases additional satellites might be just out-side the blocked location and improve thestrength of the constellation, thereby reducingmeasurement time and therefore costs.

User Interface - ReceiverSo far both sets have proven to be quite simi-lar to each other. They may look different, butoperate alike and have similar performance.However, as said before, these are utilitarianproducts and do not have to look pretty. Theyshould however be easy to operate, with aneasy user interface and readily readable dis-play. At this point the sets start to differ a little. Let’s start with the receivers. Both do not havea display, which I personally find a shame con-sidering the price tag for receivers at this pricelevel. However, both manufacturers do give theoption to read the number of satellites butchoose a different solution. The HiPer showsthe number of satellites received by blinkingthe status LED green for every GPS satellitereceived and orange for every Glonass satellite.Furthermore the HiPer shows the number of

ly similar to the TSC2.The readability of the colour touch screen isreasonable as far as LCD screens go inbright sunlight. With polarizing sunglassesboth screens become unreadable. Luckilyboth units communicate audibly as well. TheTSC2 is the easiest to understand in thisrespect with spoken instructions. Forinstance, a lady will tell you that the PDOPis high and that you will have to wait until itgets better. Under the same condition theFC-100 just beeps in different tones (which isan option on the TSC2 as well). Although dif-ferent, both have the same effect and allowthe surveyor to concentrate on other issueslike holding the survey pole steady andlevel.

rover satellites on the survey controller. The R8on the other hand shows both the number ofbase and rover satellites (and power level) onthe survey controller but does not indicate theexact number of satellites on the receiver.

User Interface – Survey ControllerThe Topcon FC-100 survey controller, whichwas delivered with the set, does not have akeyboard so all input has to be done using

the touch screen and stylus.With the Trimble TSC2 all inputcan be done using a keyboardas well as via the touch screen.However Topcon also suppliesthe FC-2000, which has a fullkeyboard and should be relative-


Specia l

HiPer Pro base station and survey controller FC-100.

HiPer Pro connection ports and status LEDS.

Prod_GEO_4_2006 29-05-2006 15:07 Pagina 41

The user interface for the TSC2 is graphicallymore advanced than that of the FC-100, butthe operation is similar. For the type of sur-vey I performed both controllers roughlyhave the same options. The TSC2 felt morerobust than the FC-100, but one needs toremember that both controllers are of a dif-ferent class. For a true comparison I wouldhave had to compare the TSC2 to the FC-2000 which are quit similar, but the latterwas not included with the test set.

Data TransferAfter the survey it was time to transfer thedata from the survey controller to the com-puter. With both units the data can either bedirectly transferred from the job file to theprocessing software on the computer or it

nates to the ‘true’ coordinates. As a true userI did not read the manual and overlookedthe recomputed option that had to be select-ed after changing the base coordinates. Butonce that was solved it worked like a charm.Both packages show the survey both graphi-cally and per point. After processing is done,the data can be easily exported from bothpackages. In contrast with the survey con-troller, the Trimble software has more exportoptions than the Topcon software. Just for the fun of it, I exported the datasetfrom the Topcon software to a shape file andthen used Global Mapper software to rectifyan ‘aerial’ photograph of my back yard usingthe GPS survey. Global Mapper, which is aprogram for easy viewing of a multitude of(geo) graphical formats, has the option toread both shape and (geo-referenced)images and rectify the latter based on anumber of other data sets. The result? Notbad for an amateur on a Saturday afternoon,especially when considering the angle atwhich the photo was taken.

ConclusionBoth sets performed as expected during thetests although there are some differencesbetween the two. Differences are minimaland subjective at the least. The table belowlists some of the more important differencesfound between the two sets.

To answer the question: is more better? Theanswer is yes, but every user has to decidefor himself whether the additional satellitesare worth the extra money. When measuringin areas with relatively small obstacles it canbe a benefit and greatly speed up the sur-vey. But don’t expect miracles, a partiallyblocked horizon means that no matter howmany satellites are available, the result willalways be of low quality.

Huibert-Jan Lekkerkerk

([email protected]) is a freelance

writer and trainer in the field of positioning and

hydrography. For more information about the

receivers, visit www.topconeurope.com or

www.trimble.com. For more information on Global

Mapper, visit www.globalmapper.com.

can be exported to a card on the surveycontroller. The method used for exporting toother software packages differs between thetwo. The Topcon software allows directexport towards a number of specific formatswhile the Trimble uses XML as an intermedi-ary format to export to a number of differentsoftware packages in this way allowing theuser to specify custom export formats.

ProcessingBoth manufacturers delivered the sets withaccompanying processingsoftware: TrimbleGeomatics Office andTopcon Link. One of thethings to do was tochange the base coordi-


Art ic le

R8 connection ports.

Processed HiPer Pro points in Topcon Link software.

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 43


Art ic le

Improving Awareness of AssetsThat Require AttentionThe Facility Maintenance Crystal Ball

Improving Awareness of AssetsThat Require Attention

Today’s fast-paced world requires corporations to respond quickly to customer needs

while providing reliable service of a given commodity. While this may seem like an

impossible task to accomplish, many service-oriented organizations-including utilities

and municipalities, among others - are developing strategies specifically targeted to

address these needs.

By J. Peter Gomez

‘Whack-A-Mole’ GameMore than 20 years ago, a veteran electriclineman once told me that responding to asystem outage was often like playing the nov-elty ‘Whack-A-Mole’ game, as seen at manylocal amusement parks. “If only I had a biggerhammer, I could win every time!” a gamepatron was likely to say. To meet today’s highefficiency and high reliability consumer needs,such a hammer is being developed in the formof sophisticated analytical tools that enablepredictive analysis to be performed at a vari-ety of levels on a multitude of devices.

Enterprise Asset Management ModelThe power of integrated data systems hasproven to be a key enabler in supportingthese tools and the foundation of true enter-prise asset management programs. EnterpriseAsset Management (EAM), is defined as amethodology to optimize and apply strategies

related to asset lifecycle investment and workplanning decisions. It should also be notedthat EAM is not so much about doing thework better but rather becoming better atdeciding what kind of work to do, and whereand when to do it. In general, EAM systemsare implemented as part of a work manage-ment system with the ability to record inspec-tion and operational histories to establish spe-cific criteria—which, when met or exceeded,can automatically trigger the creation of workorders against that particular type of asset.

‘Sweat the Assets’In order to effectively manage assets, it is criti-cal to determine performance metrics so thatthese values can be used as a benchmark fortracking improvement and work activity on agiven asset. This ability allows an organizationto ‘sweat the assets’ and ensure they arebeing used as effectively and efficiently as

possible. Another primary business driv-er of this approach isthe ability to proac-tively respond to service reliability issuesbefore they result in an interruption of servicefor a client. As such, many solution providershave developed tools that leverage informa-tion contained on assets from a variety oflegacy data sources, and they’ve integratedthat information with real-time and near-real-time data as appropriate. It is this ‘smart’ tech-nology that is taking the asset tracking andmonitoring activities to a whole new level.

Asset Optimization ToolsData latency has become a critical componentwhen it comes to proactively responding to agiven situation. However, in order to meet thehigh reliability service level demands, servicecompanies must have a firm handle on thestatus of their critical assets. Virtually all of thedata tools currently on the market use wirelesstechnology as a means of transmitting databack to a central repository where systemplanners can monitor activity and recommendchanges in operation—usually within minutesof receipt. This has become especially benefi-cial for the monitoring of remote sites—where-as in the past, time-consuming manual track-ing was the only viable option. Now, theability to replace assets that are nearing theend of their useful life can be foreseen andbudgeted accordingly. It is through this approach that reliable serviceand timely customer response are beingaddressed and critical operating data arebeing captured. With the incorporation of thistechnology, I often wonder what my now long-since retired electric lineman friend—who sosuccinctly compared the reactive approach ofresponding to a system outage to the ‘Whack-A-Mole’ novelty game—would have to say. Ilike to think he would say something to theeffect of, “Now that’s what I call building abigger hammer!” Somehow that analogyseems to sum it up perfectly.

J. Peter Gomez ([email protected]) is

a GITA Past-President and Board Member

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 45

Fiona Hopkinson

([email protected]) works for

Intergraph Mapping and Geospatial Solutions

and is based in the UK.

The Human Element – MakingChange HappenWhether a natural disaster such as the Tsunami, or Hurricane Katrina, an epidemic

such as SARS, ‘Foot and Mouth’ or Bird Flu, or for the protection of citizens in the

wake of New York, Madrid and London, the importance of smooth, seamless, ‘real

time’ collaboration between key agencies is literally a matter of life or death.

The need to overcome organizational andcultural challenges was consistently outlinedat the Defense Geospatial Intelligence Eventin London earlier this year, and is a com-mon message across industry. It is greatthat we have the technology and the stan-dards – it is, however, the human elementthat is the current barrier to effective collab-oration. Around the globe, within countries,we have multiple departments, with variedfunding, and diverse goals and objectives,when in non-crisis scenarios. How can thesedisparate agencies be brought together tooperate as one, in an instant, whenrequired?One step is legislation. Significant legislativemeasures have been undertaken to enablethis, such as the establishment of thedepartment of homeland security in the US,and the Civil Contingencies Act in the UK.

Such a challenge of integration and co-oper-ation is not unique to the geospatialdomain. We should look beyond our geospa-tial world, and learn from the experts inChange Management, which is what this real-ly amounts to.

As market dynamics change and competitionbecomes more aggressive, previously suc-cessful companies need to facilitate change,and often very significant change, not onlyto main profitability but to survive. A power-ful example can be found in the turnaroundof IBM. When Lou Gerstner joined in 1993reported a record net loss of $8.1 billion,upon his departure reported a net income of$7.7 billion. IBM had been written off as allbut dead by well respective publicationssuch as the Wall Street Journal and theEconomist. Critical to ensuring the survival ofIBM was new leadership; interestingly aleader was not being sought specifically from

the IT domain, but a leader with the charac-teristics to stimulate and instigate change.This was spelt out in the recruitment direc-tive:

‘What is critically important is the personmust be a proven, effective, leader – onewho is skilled at generating and managingchange’.We can learn from the approach of this high-ly respected champion of change. Gerstnermade it a top priority to articulate his modusoperand, and to get inside both the busi-ness, the customer and their competitors– tounderstand first hand the challenges facedand the hurdles to be overcome. Gerstnerand his executives always had their earsopen to any level within the organizationand actively sought input. In doing soGerstner knew his challenge intimately andalso secured the support of the soldiers ofthe change – the people of the company.Consequently employee targets were trans-formed to further stimulate the change, andreflect the goals of the overall business.

Thus, the principals to overcome organiza-tional and cultural challenges are pretty clear:• Effective communication;• Full and active executive support;• Employee involvement;• Organizational planning and analysis

and widespread perceived need for thechange.

Latest News? Visit www.geoinformatics.com June 2006 47

It is all about listening,

understanding, communicating

and acting.

Column

It is all about listening, understanding, communicating and acting.The legislation, and cross agency associa-tions, are a powerful first step in making thishappen. It is however, imperative that thereis an end-to-end understanding and review,of the softer dynamics and black and whiteobjectives of each organization, to enablesynergy in end goals. It is all too easy to getcaught up on the top-level goals withoutunderstanding the nuts and bolts of thebusiness; the cogs need to be in place, andthen realigned to drive the organization andintegration forward…. and fast.

Who Says Elephants Can't Dance? Inside IBM's Historic Turnaroundby Louis V. Gerstner Jr. (to be found on www.amazon.com)Change, Change, Change: Change Management Lessons From the Fieldhttp://humanresources.about.com/od/changemanagement/a/change_lessons.htm

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 47

International Scientific Symposium on ‘Not Just a Scientific Topic Anymore’International Scientific Symposium on

Scientists met other scientists, listened to each other’s presentations and exchanged

knowledge on remote sensing and satellite images. Setting: sunny Enschede, the

Netherlands, at the International Institute for Geo-Information Science and Earth

Observation (ITC), May 8-11.

By Sonja de Bruijn

Pre-symposium EventsFor some of the 500 attendees, mostly scien-tists from all over the world, the mid-termsymposium on ‘Remote Sensing: From Pixelsto Processes’ meant meeting each other again,and refreshing memories from the past whenbeing a student at ITC. Although the meetingofficially started May 8 there were pre-sympo-sium events on May 6, and a visit to theKeukenhof Gardens in Lisse, the Netherlands,one day later, could be found on the programlist as well.Naturally the technical sessions on topics like‘Advanced Classification Techniques’,‘Information Extraction from Hyperspectraldata’ and ‘OpenDragon: Free GeoInformaticsSoftware for Education in DevelopingCountries’ were dominant during the officialfour symposium days. According to John vanGenderen, President of the ISPRS TechnicalCommission (TC) 7 (see information on ISPRSelsewhere in this article), calibration and vali-

dation of data, as well as data fusion anddata mining, are ‘hot topics’. He tells aboutthe project undertaken by one of the severalworking groups of TC VII on data fusion. “Onetype of data is not sufficient to solve a prob-lem. Besides doing optical observations youcan do radar or thermal measurements inorder to observe the earth. This means youhave to fuse optical, radar, thermal but alsohyperspectral, statistical or perhaps even his-torical data of high quality.”

Another topic is data mining. Van Genderen:“It means being able to extract a specific typeof information from data that is stored insome place and possibly thirty years old.Software is currently being developed that iscapable of extracting certain values of certainareas over time. This enables a precise com-parison of data from the past and the pre-sent.”Van Genderen is quite enthusiastic about one

working group that deals with ‘Innovativemethods for less developed countries’. Heexplains why he likes this project so much:“These people often don’t have all the fantas-tic devices we have but show a lot of creativi-ty in solving problems in their country byusing remote sensing data. The nice thing isthat you see a transfer from technology andknowledge between the western world andthese less developed countries. We learn fromthem, which accelerates solutions.”

RelationPrices of satellite images are going down, butespecially high-resolution images can still bequite expensive. Van Genderen however thinkscost is not a real issue. “It is all about therelation between overall costs and the costs ofthe images needed. If you can retrieve a lot ofinformation from these data, like the localiza-tion of new energy resources, costs are notreally the issue anymore.” He continues:“When looking at an infrastructural project thecosts might be neglectable, however for amunicipality that needs high-resolution imageson a monthly basis, for example to detectchanges in infrastructure or vegetation, it

June 200648

Art ic le

Getting to know each other, with John van Genderen, President of the ISPRS Technical Commission VII, in the middle.

The International Society forPhotogrammetry and Remote Sensing(ISPRS, www.isprs.org) is a non-govern-mental organisation aimed at enhancinginternational cooperation between world-wide organisations with interests in pho-togrammetry, remote sensing and spatialinformation sciences. It consists of nearly100 national and 10 regional societies andorganisations and its scientific and techni-cal programs are organised by eightTechnical Commissions. Each Commissionholds its own mid-term symposium withinits country once every four years.Commission VII concentrates on ThematicProcessing, Modelling and Analyses ofRemotely Sensed Data. This Commission,led by President John van Genderen, isbased in the Netherlands and from May 8-11 they organised their symposium called‘Remote Sensing: From Pixels toProcesses’ at ITC, the Netherlands. In theOlympic years all Commissions cometogether, with Beijing being the location ofthis congress in 2008, one month beforethe Games get started.

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 48

might still be too expensive. An IKONOS stere-opair image of let’s say 11 km square size willcost $ 12,000 to $ 15,000, and then there’sadditional costs for things like the softwareneeded to work with these data. In Europe asatellite image will cost you about € 100. Nowthat ORBIMAGE (Quickbird) has taken overSpace Imaging (IKONOS) to form GeoEye andthus covering the larger part of the market,there is not that much competition at themoment. But I guess new players will enterthe market soon and this might bring the pricefurther down.”

Technical EducationSo costs are not the bottleneck, but what is?“Education”, is Van Genderen’s firm answer.“Though working here at ITC I have to admitthat the focus has been too much on technicaleducation. People studying at ITC going backto their own country usually become active ona technical level. Of course some of them end

never learnt how to do this at school.Information on these techniques should bebrought into the open; it is not just a scientifictopic anymore.”



up in management or politics, and these peo-ple are aware of the possibilities of remotesensing. However it is really essential that alldecision makers are aware of these possibili-ties, because unfortunately this is not thecase. But also municipality workers need toknow how to work with things like GPS. They


Art ic le

n Remote Sensing in the Netherlandsn Remote Sensing in the Netherlands

ITC, the International Institute for Geo-Information Science and Earth Observation (www.itc.nl), islocated in Enschede, the Netherlands. The scientific staff consists of around 130 professionalsfrom more than 30 countries. Essential at ITC are international knowledge exchange, as well asthe focus on mid-career professionals who can potentially influence decision-making processeswithin their organisations. The Institute offers two degree programmes, a Master of Science(MSc) and a Master degree programme in Geo-information Science and Earth Observation.Diploma and certificate programmes are also offered. The degree programmes cover the follow-ing courses:• Applied Earth Sciences; • Geoinformatics;• Geo-information Management; • Land Administration;• Natural Resources Management; • Urban Planning and Management;• Water Resources and Environmental Management.Besides these international educational programmes ITC provides research and project serviceswith respect to geo-information science and earth observation using remote sensing and GIS.

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 49

Part 3: Error SourcesPractical Satellite Navigation

In the previous articles the position determination of GPS was discussed. The GPS

position, based on the C/A code, nowadays has a precision of approximately 5 – 20

meters. With the P code, more precise results can be achieved (1 - 5 meters). The

difference in precision between the C/A and P code is largely due to the length of the

code and the broadcasting of the P-code on two frequencies. There are however a

number of error sources that influence the precision of the GPS position and which can

degrade the position with meters. This article will give a brief overview of a number of

large error sources that can influence the position determination.


Gravity FieldSatellites are equipped with very accurateatomic clocks, as was discussed in the previ-ous article. Nonetheless there are still smallerrors at work mainly due to variations in thegravity field of the earth. As a result of relativityrelated errors, the satellite clock can showsmall discrepancies when compared to themother clocks on earth. Furthermore smallchanges in the gravitational field of the earthwill cause small changes in the satellite orbits.It was already shown that ground stations areconstantly tracking the satellites. These controlstations determine the corrections for bothorbit and clock and transmit these to the satel-lites once a week. This implies that it is possi-ble to calculate satellite positions based on analmanac which is almost a week old and possi-bly incorrect. For GPS applications where accu-racy is of utmost importance, the correctalmanac is therefore applied afterwards to theraw satellite measurements (post-processing).

Selective AvailabilityShortly after the GPS system was completedtests showed that the system functioned bet-ter than expected. Instead of the predictedprecision of 50 –100 meters for the civil sig-nal (C/A code – Standard Positioning Service)the results were in the order of 10 – 20meters. Although these results were verypositive in a scientific sense, the Americangovernment felt these results were a threat.The main reason for this was that all userscould calculate positions with a precisionthat was almost equal to that of the militarysignal (P-code – Precise Positioning Service).It was thus decided in 1989 to introduceerrors in the C/A coded signals, bringing theprecision artificially back to 50 – 100 meters.This signal degradation was called SelectiveAvailability (SA) and has been in use for overa decade, with the exception of the first Gulfwar in 1991 when the American army did nothave enough military GPS receivers for their

own troops. On the first of May 2000, presi-dent Clinton declared that, as a result of thebroad use of GPS and DGPS, there was nofurther need to continue SA and it wasswitched off. This switch-off was howeverconditional with the reservation that it couldbe put back on in times of emergency. Untiltoday SA has been switched off, even afterthe events of September 11.

TroposphereThe earth atmosphere consists of a numberof layers, the troposphere being the firstlayer (up to a height of approximately 13kilometres) where the weather is formed.Since the GPS satellites are orbiting highabove the earth, their signals need to crossthe atmosphere before reaching our receiver.Factors like humidity influence the speed oflight, and as such delay the GPS signalsresulting in travel time errors in the order oftens of meters.

April/May 200648

Art ic le

Figure 1: effect of satellite elevation on the path travelled.

Prod_GEO_3_2006 gtb-5.0 26-04-2006 12:35 Pagina 48

GPS receivers do employ an atmosphericmodel to correct for these delays. Localweather variations cannot be modelled how-ever and will result in errors of meters in thepseudorange measurement. The amount ofdelay depends on the time it takes the sig-nal to travel through the atmosphere, whichin turn depends on the satellite elevationabove the horizon, see Figure 1. Satellitesdirectly above the horizon will cause thesmallest error, and as a rule of thumb, keepthe elevation of the satellites used above 10°to 15° in order to reduce the potential erroras much as possible.Another method by which tropospheric errorcan be reduced is the use of a multi-frequen-cy receiver. It has been demonstrated thatthe amount of delay depends on the fre-quency of the radio signal. If we measurethe travel time for both the L1 and the L2frequency, we can estimate the troposphericerror to some degree. Most dual frequencyreceivers use the P-code for correcting theatmospheric error. Since this code is trans-mitted on both frequencies (L1 / L2) but hasan unknown starting point, it cannot beused for determination of the absolute traveltime. We can however take differential mea-surements since the code starts at the samepoint in time for both frequencies.

IonosphereThe ionosphere is the layer in the atmospherereaching from 50 to 500 kilometres. The sunionises the air in this layer, creating a chargedparticle layer. A striking example of this ionisa-tion is the polar light. The ionised particlesdelay the GPS signal, creating errors of up to30 meters in the daylight or 6 meters at night.Large sources of ionisation are the so-calledsunspots and related magnetic storms. Thesesunspots have an 11-year cycle with the nextpeak occurring in 2011 – 2012, see Figure 2.

MultipathJust as light is reflected by a shiny surface,radio signals can be reflected by things likethe water surface, tanks filled with oil andwater, but also by cars and ships or bridges.The reflected signals will interfere with the sig-nals that are received via a direct path, seeFigure 4. The receiver may start using thereflected signal, which has a longer traveltime, instead of the direct signal. As a resultthe position will be calculated incorrectly, withthe position shifting in the direction of themultipath source.Since multipath is hard to correct for, it is better to prevent it altogether. As the first rulein preventing multipath is to keep the antennaas far away as possible from reflectors.Enlarging the elevation mask of the receivercan be of some help as can changing theheight of the antenna. A multipath error willlast a couple of minutes and will disappear assoon as the signal is no longer reflectedtowards the antenna. Nowadays most professional GPS antennashave a built-in ground plate or choke ring, seeFigure 6, which prevents the reception ofreflected signals from under the antenna hori-zon.

User ErrorsThe main sources of error in GPS measure-ments are user errors or as they are usuallycalled, blunders. As a rule, blunders can beprevented by a consequent measurementstrategy using as many control options aspractically possible. Common blunders are:• Measuring too close to objects with either

multipath or shielding from the horizon as a result. This results in a degraded

At the moment we are approximately at theminimum of the solar cycle. This effect will also occur around the year inlocations with a large amount of exposition tothe sun (equator, around noon).With a small amount of ionisation the problemwill be measurement errors. When there is alot of activity, the GPS signal can be influenced in such a way that reception isimpossible, see Figure 3. When using DPGSsystems the effective range can, as a result of the solar activity, be reduced with a factor 2to 4. Ionospheric errors as a result ofsunspots cannot be predicted, but the regular ionisation of the atmosphere can bepredicted using an ionospheric model. Amulti-frequency receiver can resolve theseerrors in the same manner as with the tropospheric error.

April/May 2006Latest News? Visit www.geoinformatics.com 49

Art ic le

Figure 2: number of (predicted) sun spots for the current solar cycle. (source: www.taborsoft.com )

Figure 3: RTK GPS measurements in november 2001. The scale for both X,Y and Z is 0.25 meters. The Kp index isan indication of the radio environment in the ionosphere (red = bad). (source Kp index: http://www.sec.noaa.gov)


position and a difficulty to detect. Largesteel structures such as cranes or mastswill shield the horizon just as a bridge ora tree, a fact that is not always appreciat-ed in the field;

• The use of height aiding without enteringthe correct antenna height above sealevel. As was discussed in the previousarticle, the use of height aiding shouldbe questioned these days since sufficientsatellites are available for a good posi-tioning fix under normal conditions;

• Incorrect initialisation position after acold start of the receiver. This will notresult in an incorrect position, but in noposition reading altogether;

• Incorrect geodetic settings. GPS calculatesall positions in WGS84 coordinates, butmost receivers have the option to trans-form these to any other coordinate sys-tem for presentation on the screen. Withmost receivers the output message willhowever contain WGS84 coordinates.Errors as a result of the selection of anincorrect geodetic datum can be as highas hundreds of meters, see Figure 5.

Quality ControlTo gain insight into the quality of a calculat-ed position there are a number of qualitycontrol parameters available in most GPSreceivers. The most important one probablyis the Dilution of Precision (DOP). The DOPdescribes the geometric strength of the satel-lite configuration, or in other words thespreading of the satellites around the hori-zon. When all satellites are on one side ofthe horizon, see Figure 7a, the receiver willcalculate a high DOP value. There are a num-ber of DOPs available, but with ordinary GPSpositioning the Horizontal DOP (HDOP) andgeometric DOP (GDOP) are possibly the mostimportant ones.Next to the DOP, some receivers have theability to calculate the so-called Line ofPosition Mean Error (LPME). This is an indica-tion of the precision of the position itself andwill factor in other parameters like the traveltime measurement.Some manufacturers present the user with aso-called quality figure that is said to indicatethe precision of the position determination.This quality figure is usually calculated from

parameters like the HDOP and LPME. As arule one should treat these figures with duecaution since the formula used to calculatethis is generally unknown to the user.

SummaryFrom this article it can be seen that there area large number of error sources influencingthe GPS position determination. We shouldtake these error sources rather serious whenperforming high quality GPS measurements.A number of the errors described in this arti-cle can be corrected using DGPS, which willbe described in the next article.




hydrography.

April/May 200650

Figure 4: Through reflection of GPS signals a longer travel time is registered, resulting in position errors.

Figure 6: Position error through an incorrect choice of geodetic datum. In theexample we read ED50 positions (centre). The WGS84 positions from the GPSreceiver are 180 meters further in coordinates.

Figure 7: the Dilution of Precision is high (a) when all satellites are on one side of the antenna and low(b) when there is an even geometric spreading of the satellites.

Figure 5: antenna with choke ring to prevent multipath(source: www.ipgp.jussieu.fr).


International Symposium on 'Biggest Contribution Conceptual Rather Than Scientific'International Symposium on

In honour of altimetry, oceanographers, glaciologists, hydrologists and geodesists from

around the world have gathered at the ‘15 Years of Progress in radar Altimetry’

symposium in Venice, Italy. They presented and discuss the current and future scientific

and operational applications of radar altimetry, and how altimetry data can be used in

synergy with other satellite and in-situ results as well as computer modelling.

By Joc Triglav

VeniceThe measurement of sea level is a topic ofspecial significance for Venice because thelife of Venetians is strictly connected to thesea level. This is one of the reasons whyVenice was chosen to host this internationalsymposium. The event took place in the 15thyear since the launch of ESA's ERS-1, whosepayload included the Radar Altimeter (RA).Organised by the European Space Agency(ESA) together with the French Space Agency(CNES), the '15 Years of Progress in RadarAltimetry' symposium was being held inVenice Lido from 13 to 18 March 2006, andwas a major scientific event on a class ofspace-borne sensor that precisely records theheight of the global sea surface along withthat of freshwater bodies, land surfaces andthe icy cryosphere.

Study of the OceanMeasuring the ever-shifting sea surface radaraltimetry is valuable to several scientific andapplication fields like monitoring El Niñoevents, mapping the circulation of Earth'socean currents – such as the Gulf Stream –and quantifying the impact of global warm-ing on sea levels. Warm ocean currents cancause sea surface height to rise up to ametre above the surrounding waters. Averagewave height and wind speed canalso be derived. Along with otherspace techniques andin-situ networks, altime-try is also a key compo-nent of emergingocean forecast oper-ational systemswhich provide,severaldays/weeks inadvance, essen-tial informationfor ship routing,oil spill driftmonitoring,marine resourcemanagementand climateforecasting.Radar altimetryalso allowsresearchers topeer indirectlybeneath the waves:undersea bathymetryfeatures are revealed by per-sistent, slight undulations ofthe marine geoid – the equipoten-tial surface in the gravity field of the Earththat coincides with the undisturbed meansea level – created by minor variations in theEarth's gravity due to the sea floor relief.

Land SurfaceOver land, radar altimetry delivers enhanceddigital elevation models (DEMs), and recentimprovements in processing algorithms havemade it possible to monitor the levels ofrivers and lakes, allowing more precise quan-tifying of the vast amounts of freshwaterthat flows across Earth's land surface. Forthe Cryosphere - those regions of the Earthwhere water freezes - radar altimetry has

June 200650

Conferences & Meet ings

Scientists with an interest in radar altimetry have gathered from around the world in Italy at the ‘15 Yearsof Progress in Radar Altimetry’ symposium. Sponsored by ESA and the French Space Agency (CNES), thesymposium was being held in Venice Lido from 13 to 18 March 2006 (Credits: ESA).

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 50

been successful in measuring the mass bal-ance of Greenland and Antarctic ice sheetsand providing initial global monitoringresults for sea ice thickness. A combined ground segment specially devel-

Distance to PlanetSince its launch in 2002, from its 800-km-highpolar orbit, Envisat's Radar Altimeter-2 (RA-2)sends 1800 separate radar pulses down toEarth per second then records how long theirechoes take to bounce back. The sensor timesits pulses' journey down to under a nanosec-ond to calculate the distance to the planetbelow to an accuracy of two centimetres. The symposium took place a few weeks afterESA received the green light from its MemberStates to build and launch a CryoSat recoverymission, Cryosat-2, which is expected to belaunched in March 2009. Thanks to its maininstrument, the Synthetic ApertureInterferometric Radar Altimeter (SIRAL),CryoSat-2 will precisely monitor changes in theelevation and thickness of polar ice sheetsand floating sea ice. These data will helpexplain the connection between the melting ofthe polar ice and the rise in sea levels andhow this is contributing to climate change. ESA has been flying radar altimeters in spaceever since the launch of ERS-1 in 1991, amass-ing a continuous 15 year dataset that coversnot only the global ocean but also freshwaterbodies, land surfaces and the cryosphere. This archive will extend further into the future.A radar altimeter will be included on theSentinel-3 mission planned to support opera-tional oceanography services. These have beendeveloped as part of the Global Monitoring forEnvironment and Security (GMES) initiative ofthe European Union and ESA.

Symposium Related EventsAlong with this symposium, three relatedevents were taking place in Venice the sameweek: the annual meeting of the Ocean

oped by CNES for altimetrymissions called SSALTO-DUACS ('Segment Sol multi-mission d'ALTimétrie,d'Orbitographie et de locali-sation précise - DevelopingUse of Altimetry for ClimateStudies') is able to combineradar altimetry data to pro-vide the best possible globalocean coverage. This makes a number of opera-tional services possible, includ-ing a French system calledMercator Ocean that provides analysis andforecasts of ocean circulation around Europefor up to a fortnight ahead. An important sci-ence result is solid evidence of a steadysea level rise averaging 0.3 millimetres ayear.

HistoryRadar altimeters were first flown inspace in the 1970s, aboard NASA'sSkylab, Geos 3 and Seasat. Initiallythese sensors were dedicated to thestudy of oceans, but as the technologyimproved so did their reach. TheEuropean experience in radar altimetrydates back to 1991, when ESA launched

its ERS-1 satellite, which included the firstRadar Altimeter (RA), precisely calibratedover the water of Venice. Since then, ESAhas continued to accumulate homogeneousdata by follow-up instruments aboard ERS-2and Envisat satellites. In 1992, as a support to the World OceanCirculation Experiment program, NASA andCNES launched the Topex/Poseidon mission,fully optimised to measure the sea surfacetopography with an unprecedented accuracy

of a few centimetres. The Topex/Poseidon mission was com-pleted at the end of 2005, after 13years of successful and continuousocean surveys. Its successor, Jason-1,was launched in 2001 and the launchof Jason-2, a joint CNES/NASA/EUMET-SAT/NOAA mission, is scheduled totake over in 2008. Also currently inoperation is the GFO mission, the USNavy's Geosat Follow-On Mission,which is a sequel to the previousGeosat mission (1985-1989).



Radar Altimetry in Italy Radar Altimetry in Italy

Altimeter-based chart showing variability of the GulfStream, with an inset showing modelled stratificationof the temperature field (red is warmest, blue is cold-est) (Credits: CNES/AVISO).

The radar altimeter offers valuable information on the state of the ocean byproviding measurements of the height of the ocean surface. Knowing theheight of the sea surface has allowed scientists, for the first time, to mapthe ocean floor (Credits: ESA).

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 51

Surface Topography Science Team (OSTST –particularly concerned with GFO,Topex/Poseidon, Jason-1/2 and Envisat alti-metric missions), the International DORISService (IDS) Workshop and the ARGOWorkshop. Doppler Orbitography and RadiopositioningIntegrated by Satellite (DORIS) is an onboardsatellite radio receiver used for precise orbitdetermination. DORIS derives it to an accura-

array of achievements, many scientists havecome to Venice to honour it for different rea-sons. According to one of the pioneers ofthe altimeter, Massachusetts Institute ofTechnology’s (MIT) Carl Wunsch, its biggestcontribution is conceptual rather than scien-tific. It changed the way scientists viewedthe ocean. The greatest achievement of thealtimeter is that it has shown us that theocean system changes rather dramaticallyeveryday. It has shifted the view of it fromthis almost geological phenomenon creepingalong very slowly to something much moreinteresting in which fluid is moving in alldirections at all times.

Joc Triglav ([email protected]) is a

contributing editor and columnist of GeoInformatics.

Have a look at www.esa.int/esaEO/ to learn more

about ESA Earth Observation and at

http://earth.esa.int/venice06/ to learn more about

the Venice Symposium.

cy of a few centimetres by detecting andmeasuring the Doppler shift on signalsbroadcast from a network of more than 50radio beacons spread across the world.These data are precious tools for improvingthe accuracy of altimetry measurements.DORIS receivers are aboard many satellitesincluding Envisat and CryoSat. ARGO is the name for an array of more than2400 profiling floats which provide tempera-tures and salinity profiles for various depthsacross the global ocean. ARGO results arescientifically valuable in their own right butcan also be combined with altimetry data forenhanced environmental and climate knowl-edge.

Ocean as a WholeKnowing the height of the sea surface tellsscientists a great deal about what is happen-ing at lower depths. Before the advent ofradar altimetry, oceanographers had no wayof looking at the ocean as a whole, which isessential because changes in one part of theocean will eventually affect the whole rest ofthe ocean. Signifying radar altimetry’s vast



Altimetry-derived mean dynamic topography of thesea surface, which is the mean sea surface height relative to the geoid, or the theoretical surface ofequal gravity around the Earth (Credits: CLS).

At the latest meeting of the European Space Agency's Earth Observation Programme Board in Paris in February2006, ESA received the green light from its Member States to build and launch a CryoSat recovery mission,CryoSat-2( Credits: ESA - P. Carril)

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 53

Part 4: Differential GPS systePractical Satellite NavigationPart 4: Differential GPS syste

Most professional users will find the precision and reliability of the standalone GPS signal below standard. The error sources

mentioned in the previous article play a large role in this assessment. Therefore, soon after the introduction of GPS, users started

looking for methods and techniques to improve the reliability and precision of GPS positioning. Next to the improvement of the

receivers themselves, a solution was found in the use of differential GPS (dGPS).


Base and RoverThe term differential GPS is derived frommeasurement technique. All dGPS systemsuse a reference station (base) in combinationwith a mobile station (rover). The baseantenna is deployed over a benchmark orcontrol point for which the position is exactlyknown. The base receiver is set to computeits position from the satellite signals. Thiscalculated position is then compared withthe benchmark position with a position dif-ference as a result. The differences foundresult from errors and inaccuracies in theentire measurement. The calculated differ-ences can now be sent from the base to therover. In the rover the corrections are appliedto enhance the rover position.There are two principal techniques used tocalculate the differences between base androver, called code phase and carrier phasedGPS. The main difference between the twolies in the part of the GPS signal used forcalculating the corrections.

Code Phase dGPSWith code phase dGPS, the base measuresthe pseudo ranges towards the satellitesusing the C/A code. The base calculates thetheoretical pseudo ranges from its (known)location to the satellite as well and comparesthe two to derive a pseudo range correction.These corrections are then sent, one persatellite, to the rover where they are appliedto the ranges measured from the correspond-ing satellites.The real error at the rover will of course differfrom that at the base, but since the satellitesare at a relatively long distance when com-pared to the distance between base androver, they are generally valid. The further thedistance between base and rover, the lowerthe accuracy of the corrections and thus theprecision of the rover position. Errors at thebase position like multi path will have a directinfluence on the quality of the dGPS signaland thus on the rover position. With codephase dGPS a precision in the order of one

meter to a couple of meters can be achieved.The actual precision depends on the distancebetween base and rover and the telemetryfrequency chosen for transmitting the correc-tions.

Carrier Phase dGPSThis technique uses the carrier wave (L1 andL2) of the GPS signal. The length of the carrierwave is in the order of 20 centimetres and hasas such a much shorter wavelength than thecode signal (300 meters). As a result carrierphase dGPS is more precise than code phasedGPS.As a consequence however, the determiningcorrections with carrier phase dGPS requiresmore computation than when using the codesignal. A large hurdle to overcome is the deter-mination of the whole number of wavelengths(cycles) between the satellite and receiver. Thiswhole number of cycles is also called the inte-ger ambiguity and needs to be resolved dur-ing the initialisation of the system. Resolvingthis is usually done with two receivers measur-ing towards at least 5 identical satellites.Between these two receivers the difference inwhole number of cycles is determined (single,double and triple differencing). From this start-ing point the receiver tracks the change incycles as the distance between satellite andreceiver changes.

Absolute PositionsThe result of a carrier phase position determi-nation is a position difference between baseand rover. No absolute positions are calculatedin either base or rover. The only function ofthe base is gathering raw data from the satel-lites and re-transmitting (or storing) these foruse in the rover. The absolute rover position isfound by adding the found ∆x, y and ∆z tothe absolute x, y and z entered manually inthe base. For practical purposes a carrier

June 200654

Art ic le

Principle of code phase dGPS. Pseudo corrections between base and satellite are determined.

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 54

phase dGPS system can thus be seen as landsurvey ‘total station’. Although it is one with-out the need to have a line of sight betweeninstrument and beacon and an effective rangeof kilometres. There are a number of carrierphase techniques in use today; the table on page 57 gives an overview of the mostimportant ones. The following definitions areimportant when using the table:• Post processing. Measurements are taken

in the field and processed in the office.Results are not visible online;

TelemetryThere are a multitude of methods to get thedGPS correction signal from the base to therover. Much used techniques are:• Radio telemetry;• Satellite telemetry;• Mobile telephone.

Radio TelemetryThis method is mostly used for small-scaleprojects where high precision is needed orwhere no regular dGPS infrastructure is inplace. With radio telemetry, the achievablerange depends on the chosen frequency bandand power used. Much used bands are theUHF band (RTK systems) with a maximumrange equal to the line of sight or roughly 40kilometres. Another widely used band is theMF band (IALA beacons) with a range of tensof kilometres. The International Association ofLighthouse Authorities (IALA) transmits free toair signals from beacons close to harbours ofshipping lanes.

A specific form of radio telemetry is the Eurofixsystem. With Eurofix, Loran-C transmitterstransmit the dGPS correction signal. Loran-C isa terrestrial radio positioning system thatseemed to become victim to the widespreaduse of dGPS. However, since then variousreports (the Volpe report - United States andHelios study –Europe) criticized the vulnerabili-ty of GPS as a sole means of navigation. SinceLoran-C uses terrestrial transmitters with highpower signals in a different frequency band itis not vulnerable to the same sources as GPS.

• Real time. The measurements are takenin the field and are online visible;

• Static initialisation. The system may notmove during initialisation, movement ofthe rover is not allowed;

• Continuous measurement. Measurementscan be taken while moving, thus creatinga continuous profile or measurement.

Height MeasurementAccurate height measurement is not possiblewith code phase dGPS. Carrier phase dGPShowever does offer this possibility and is theprimary reason for choosing carrier phase dGPSover code phase dGPS for certain applications.Carrier phase dGPS seems to replace the totalstation and level instrument as such for all butthe most accurate jobs. An important difference between the heightmeasurement of a carrier phase dGPS systemand the more traditional land survey methodsis that the height reference used is different.With GPS, heights are determined relative tothe WGS84 ellipsoid and not as with levelinstruments relative to a gravity based refer-ence or geoid such as mean sea level. Whenmeasuring over distances of kilometres, the dif-ference between the ellipsoid and geoid cancause height errors in the order of centimetresto decimetres. In order to reference the GPSmeasurements to the geoid a correction isneeded. Most geodetic type receivers and soft-ware packages use so-called geoid models tocorrect for this.


Art ic le

ms and RTK Techniquese ms and RTK Techniques

Principle of carrier phase dGPS. Position differences between base and rover are determined.

Difference for the Netherlands between the ellipsoid ofBessel and Dutch Datum (NAP), based upon the geoidof the Min (1996). (source: Dutch Geo Information andICT department of Rijkswaterstaat). European IALA dGPS chain (source: IALA).

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 55

As a stand-alone system it is however lessprecise. By combining Loran and GPS, a sys-tem is created that is less vulnerable andwhich can achieve a precision of meters evenwhen the GPS signal is interrupted. TheAmericans are fully convinced that Loran-Cshould remain active for this reason and aremodernizing their Loran-C transmitters. SomeEuropean governments however are less con-vinced and one of the Loran-C chains, theNorthwest Europe Loran-C System (NELS) isreportedly threatened to be shut down. The argument often heard is that Galileo willsolve the problems mentioned. This is not avalid argument however, since Galileo is vul-nerable in much the same way as GPS and/orGLONASS since all systems are based on thesame principles and frequency bands.

Satellite telemetryAt the moment corrections via mobile tele-phones are offered by commercial servicesonly. When dGPS signals are transmittedvia a satellite network, they can cover amuch larger area than when transmittedfrom terrestrial beacons. There are a num-ber of commercial networks based uponsatellite telemetry. An example of such anetwork is the Fugro Omnistar / Starfix net-work.A special form of satellite dGPS is WAAS(Wide Area Augmentation System) and itsEuropean counterpart Egnos (EuropeanGeostationary Overlay System). With Egnosthe - free - correction signals are transmit-ted on the same frequency as the GPS sig-nals themselves. As a result no expensiveseparate dGPS receiver is needed. The GPSreceiver however needs to be able toreceive the so-called SBAS messages thatare transmitted by geo-stationary satellites.

Multi Reference SystemsMost dGPS systems consist of a network ofreference stations whereby the stations con-tinuously check each other. As a result,errors in a single base station can be easilydetected resulting in a higher reliability.Another advantage is the possibility to usecombined corrections from multiple base sta-tions.Depending on the network, there are manyways to combine the different correctionsinto a single solution. Some receivers obtaininformation from multiple base stations andwill calculate the optimal solution basedupon the rover position. Another method isto perform the calculation in the networkitself. This way the receiver can be simplerbut we will need to transmit our position tothe network. This means that we need bi-directional telemetry. This technique oftenconsists of telemetry via the mobile telephone.

ConclusionWith dGPS techniques we cannot onlyimprove the precision of our position towithin centimetres using carrier phase dGPS,but more important, we have a means tocheck the reliability of the GPS signal itself.




hydrography.

Mobile telephoneCorrections via mobile telephone are at themoment offered by commercial services only.Dutch examples are LNR Globalcom (see thearticle on page 32 of this issue) and 06-GPSnetworks. The advantage of these networks isthat they offer a large number of reference sta-tions over a relatively small area. As a resulthigh precision is achievable without the needto erect an own base station. The main disad-vantage is the high cost when performing con-tinuous measurements. As a result these net-works are commonly used for calculating basepositions. However with the introduction ofUMTS and GPRS techniques costs will proba-bly drop considerably.


Art ic le

Overview of carrier phase techniques.

Eurofix coverage with the NELS chain. (source: www.eurofix.tudelft.nl).

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 57

What is UNIGIS? UNIGIS is a network ofuniversities co-operating to supply post-graduate Certificate, Diploma and Masterscourses on GIS by distance learning aswell as short workshops on current devel-opments in GIS. It was founded in 1990and currently includes sites in elevencountries on three continents. About 900students have taken the UNIGIS DiplomaCourse world-wide. For more information:http://www.unigis.net.

This page is a product of the UNIGISInternational Network and is authored bythe UNIGIS Port Elizabeth, South AfricaOffice. Information: UNIGIS South Africa,Port Elizabeth, Tel: +27 41 504 3668, e-mail: [email protected]: http://tutor.nmmu.ac.za/unigis

Friends of UNIGIS Organisations whichwork closely together with the UNIGISInternational Network are ESRI andIntergraph. These Friends of UNIGIS makeavailable their products for UNIGIS stu-dents for a low price and support stu-dents in MSc-projects. Currently UNIGIS isin negotiation with other potential‘Friends’. For more information on theFriends of UNIGIS Programme contact: Henk Scholten, [email protected].


Galileo Test BedGNSS are based on the premise of celestial instead of terrestrial positioning. This will not

change with the upcoming European Galileo system. But, Galileo’s full operational

constellation is currently not foreseen until 2011, with a first validation set of operational

satellites for testing several years away as well.

By Josef Strobl

TransmittersThis is where the Galileo test bed comesinto play. The transmitters emulate signalsfrom the future Galileo system, including thesimulation of time/distance delays and atmo-spheric effects. In a small area of 65 squarekilometres in and around BerchtesgadenGalileo will be in operation from early 2007. The main rationale for this test bed infras-tructure is to give receiver and applicationsdevelopers an early opportunity to evaluateprototypes and to verify the features Galileowill be offering.

Bridging the GapThe implemention of the Berchtesgaden areatest bed with its full name of Galileo Testand Development Environment (GATE) hasbeen contracted to IfEN GmbH by the

German Aerospace Center (DLR). It aims atbridging the gap between electronics labtechnology development and deployment inorbit. GATE transmitters will support allGalileo frequencies plus flexible signal gener-ation based on atomic clocks to simulatebehaviour under varying conditions.

Shifting Code PhaseWhile the different modes will require use ofa custom-built receiver terminal (‘GATE UserTerminal’ – GUT) supplied by the GATE oper-ators, in Virtual Satellite Mode (VSM) ageneric GNSS receiver is assumed. The GATEtransmitter infrastructure now fully mimicssatellites by shifting code phase, Dopplershift and signal power levels of carrier andcode forth and back in a way that the signalis perceived as coming from orbit. VSM will

primarily support the development of sys-tems and receivers, including combined GPSand Galileo devices.The GATE infrastructure will undergo a turn-of-the-year beta testing period and fromapproximately mid-2007 move to a fee-basedbusiness model. GATE users will then beable to conduct their own experiments withconfidential results, assisting with the devel-opment of innovative technologies and ser-vices based on Galileo.And yes, the idea of innovation is very muchat the heart of Galileo. While of course thecreation of an independent civilian GNSS is acore motivation and business opportunitiesfor European enterprises are hoped for,Galileo capabilities go beyond what we expe-rience from current GNSS. This starts withguaranteed signal availability and quality,includes new signal characteristics whilemaintaining GPS compatibility to reap thebenefits of a higher number of satellites insimultaneous view from receivers, and theintroduction of a two-way emergency beaconfacility.

Promises of BenefitsThe promises of benefits in the prime targetapplication domains The UNIGIS InternationalAssociation offers distance education to GISprofessionals worldwide. Acquisition of spa-tial data through GNSS as well as real-timepositioning as a foundation of LocationBased Systems (LBS) are key technologiesfor geoinformation practitioners. UNIGIS istherefore looking forward to allow students a‘glimpse into the future’ of GNSS by includ-ing Galileo into its curricula and to offersome hands-on previews through the Galileotest bed.

Josef Strobl ([email protected]) works as aProfessor at the Centre for Geoinformatics, SalzburgUniversity. More information:www.galileo-gate-com - GATE Homepagewww.wfg-bgl.info – Berchtesgaden BusinessDevelopment Agencyeuropa.eu.int/comm/dgs/energy_transport/galileo -General orientation

Educat ional Corner

±

The Galileo test bed in Berchtesgaden, close to the city of Salzburg, Germany.

Prod_GEO_4_2006 29-05-2006 15:08 Pagina 59

June 200660

Product News

Septentrio Introduces Industrial GPS/Galileo OEM Receiver Platform

Septentrio announces AsteRx1TM, a compact high-end

single-frequency GNSS receiver for demanding indus-

trial and professional applications. Besides GPS per-

formance, AsteRx1TM incorporates capabilities for full

use of the European Galileo L1 signal. The first Galileo

satellite, GIOVE-A, was launched in December 2005,

and Septentrio receivers have successfully been track-

ing all signals transmitted since January 2006 by the

new navigation satellite. It is the first product in a

new family of GNSS receiver boards from Septentrio.

AsteRx1TM is a creditcard-sized OEM board with low

power consumption and high update rates, featuring

all-in-view GPS and Galileo tracking and offering good

measurement quality for high-precision positioning

also in challenging environments. AsteRx1TM is com-

patible both with the GIOVE-A signal and with the

operational Galileo signal. Septentrio is involved in

the design of Galileo Test User Receivers at all stages

of the Galileo program, from early testing to final

deployment and in the development of commercial

user receivers for precision-demanding applications.

Septentrio expects to start shipping AsteRx1TM at the

end of the summer of 2006. Septentrio Satellite

Navigation NV designs, manufactures, markets and

supports high-end OEM GNSS receivers for profession-

al navigation, positioning and timing applications.

The company has an international team of experts in

all areas of satellite navigation receiver design and

applications.

Source: Septentrio

Internet: www.septentrio.com

Leica Geosystems Introduces Leica ScanStation

Leica ScanStation, a 3D laser scanner with four ‘core’

total station features:

• Full field-of view (FOV);

• Survey-grade dual-axis tilt compensation for

traversing and re-sectioning;

• Survey-grade accuracy for each measurement;

• Excellent useful measuring range.

Leica ScanStation retains the FOV of its predecessor,

the Leica HDS3000 scanner, with a maximum 360

degrees horizontal FOV and maximum 270 degrees

vertical FOV. With this FOV, ScanStation can scan

overhead while simultaneously using scan targets

spread optimally at ground level for accurate registra-

tion/control. This type of logistical freedom is similar

to that of a total station and provides valuable versa-

tility and project savings for accurately capturing

overhead structures such as ceilings, bridges, over-

passes, domes, facades, pipe racks, columns and

towers. Integrating the same one-second resolution,

dual-axis (tilt) compensator as in Leica Geosystems

total stations, Leica ScanStation can be used with

traditional traverse and resection workflows for addi-

tional field and office savings.

Leica ScanStation – and its sister Leica HDS3000

scanner – achieves survey-grade accuracy for each

scan point without averaging. This lets users take

advantage of the ability to ‘click on’ individual scan

points and use them directly for survey-grade coordi-

nate and distance measurements with confidence in

their accuracy.

With a maximum range of 300m (90 percent surface

reflectivity), a narrow beam and ultra-fine scanning

capability, Leica ScanStation addresses the vast

majority of as-built and topographic survey projects

for which users would consider the use of reflector-

less instruments. Leica Geosystems will continue to

offer Leica ScanStation’s predecessor scanner, the

Leica HDS3000 time-of-flight scanner (without dual-

axis compensation), and the ultra-high speed Leica

HDS4500 phase-based scanner as standard products.

Leica Cyclone v5.5 is being announced simultaneous-

ly as companion software for operating Leica

ScanStation in re-section, back-sight and traverse

workflows.

Source: Leica Geosystems

Internet: www.leica-geosystems.com

Crescent A100 smart antennaCSI's Hemisphere GPS

CSI's Hemisphere GPS division announced its new

Crescent A100 ‘smart antenna’ that combines a GPS

antenna with a GPS receiver featuring Hemisphere's

new high-performance Crescent OEM module.

The Crescent A100 features:

• Update rates of up to 20Hz;

• Radar-simulated pulse output to determine

ground speed;

• CAN and serial communication for compatibility

with many devices and Interfaces;

• A LED that indicates when the unit has power,

when it is tracking GPS, and when it has a dGPS

solution;

• Mounting by using fixed or magnetic options;

• Low, compact profile to avoid potential overhead

obstructions.

The Crescent A100 also features Hemisphere's

COAST(TM) and e-Dif(R) technologies. COAST software

enables Hemisphere receivers to utilize old differential

GPS (DGPS) correction data for 40 minutes or more

without significantly affecting the quality of position-

ing. When using COAST, receivers are less likely to be

affected by differential GPS signal outages due to sig-

nal blockages, weak signals or interference. The

Crescent A100 will replace Hemisphere's existing GPS

smart antenna products - the Seres and AgIQ - and

those under the brands of Hemisphere's OEM part-

ners, including agricultural industry partners.

Source: CSI's Hemisphere

Internet: www.csi-wireless.com

Industry News 4-2006 29-05-2006 14:58 Pagina 60


Product News

Launch Leica MobileMatriXv1.51

With its newly launched Version 1.51, Leica

MobileMatriX now fully supports a Multi-Sensor GIS.

Within a Multi-Sensor GIS field crews can attach several

sensors – TPS, GPS, Levels and Laser Range Finders -

at the same time and also can measure with various

sensors simultaneously. By accurately synchronizing

data from various independent sensors, Leica

MobileMatriX manages measurement processes and

storage of those in one common database directly.

Leica MobileMatriX, a mobile GIS - the natural expan-

sion of the enterprise database into the field - allows

the user to add points, measurements and features

either using Total Stations (TPS), Global Positioning

System (GPS), Level Instruments or other sensors such

as Laser Range Finder. The concept of a task-oriented

implementation of geodetic measurements in a mobile

GIS allows a fast, immediate and cost-effective data

acquisition. Furthermore, since the software is graphi-

cally based, data quality and completeness can be

checked immediately as data is acquired, which avoids

expensive re-measurements when quality control activi-

ties in the office detect deficiencies. By connecting level

and GPS sensors simultaneously to Leica MobileMatriX,

field crews can measure accurate locations with GPS

and parallel they can update the less accurate height

information with a level measured height. This process

is called Height Modernization and is possible by the

Multi-Sensor support in Leica MobileMatriX v1.51. The

Height Modernization utilizes GNSS and TPS technology

together with level instruments to improve all mapping,

surveying and engineering activities and establish accu-

rate and reliable heights – all within one mobile appli-

cation. All this can be done with Leica MobileMatriX

v1.51.



Leica Geosystems Launches Cyclone 5.5 for High-Definition Surveys

Leica Geosystems launched Leica Cyclone 5.5 soft-

ware. The new software version lets users take advan-

tage of traverse, back-sight, and resection capabilities

of the new Leica ScanStation laser scanner for more

cost-effective as-built and topographic surveys.

Cyclone 5.5 also lets users create plant as-built mod-

els more efficiently from laser scans. New features in

Cyclone-SCAN and -REGISTER modules pace the sur-

vey-grade, dual-axis level compensation capability of

the new Leica ScanSation laser scanner. With these

new features, Leica ScanStation users can take advan-

tage of (1) resectioning - or ‘free stationing’ - methods

for direct, field geo-referencing of scan data and (2)

traversing, including calculation of traverse

closures. Standard survey-style reports,

including error calculations, are generated for

both resectioning and traversing. The new

Leica Cyclone 5.5-supported workflows offer

field and office labor savings. Savings result

from placing & surveying up to two-thirds

fewer scan targets and from a reduced need

to execute office registration processes, as

registration & geo-referencing can now be

done automatically in the field. The new

workflows and software features also shorten

a surveyor’s learning curve for this cutting-

edge technology as these workflows are all standard

methods used with a total station, an everyday sur-

veying tool. Leica Cyclone 5.5 also continues to sup-

port registration and geo-referencing based on scan

targets, modeled objects, and ‘cloud-to-cloud’ meth-

ods. Together with resectioning, back-sighting, and

traversing, this set of workflow options provides users

with valuable added flexibility and cross-checking

aids.



Thales Introduces Z-Max.Net GPS Receiver

Thales presents Z-Max.Net, a next-generation,

network-capable GPS receiver system for

boundary, topographic and construction

surveys. Z-Max.Net offers surveyors

expanded communications capabilities,

simplicity of operation, RTK performance and

flexibility to meet a wide range of surveying tasks. Z-

Max.Net provides NTRIP, GPRS and RTCM V3.0 net-

work communication. Z-Max.Net offers multiple oper-

ating modes, configurations and communication

protocols. Detachable modules make configuration

changes and system upgrades possible. Z-Max.Net

can function in every mode of operation, RTK or

post processing, as a base or rover, and also in a

VRS or FKP network. As a standard feature, Z-

Max.Net offers free wide data format compatibility,

including RTCM V2.X, CMR, CMR+, DBEN, DSNP,

RTCM V3.0 and NTRIP, and can be integrated with

other equipment. Z-Max.Net can be adapted to meet

of local conditions by communicating using Pacific

Crest UHF, Thales UHF, GSM, or a unique combined

UHF and GSM/GPRS module. For enhanced coverage

in North America Z-Max.Net also features a new inter-

nal modem to provide full coverage of the GSM/GPRS

bands from 850 through 1900 MHz. Z-Max.Net offers

two-second initialization, extended operation up to

50 km (30 miles). The comprehensive office software

package, GNSS Solutions, includes all of the tools

required to successfully process GPS, GLONASS and

SBAS survey data. Focusing on simplicity, the soft-

ware guides surveyors through mission preparation

planning, processing, quality control, reporting and

data exporting.

Source: Thales

Internet: www.thalesgroup.com/navigation

Spatial Express ApplicationLizardTech

LizardTech announced further support of JPEG 2000

within its Spatial Express application which enables

storage of MrSID and JPEG 2000 images natively in

Oracle Spatial 10g. Oracle Spatial 10g provides a

robust foundation for storing and retrieving geospatial

data from Oracle Database 10g. In addition, because

Spatial Express uses the Oracle Spatial GeoRaster API,

applications will be able to retrieve and view JPEG

2000 and MrSID imagery from Oracle Spatial 10g.

Organizations no longer have to wonder whether their

application will support various file formats because

Spatial Express allows users to choose their image for-

mat and begin work.

Source: LizardTech

Internet: www.lizardtech.com


June 200662

Product News

Leica fieldPro, a mobile CAD software, is an on-site

and on-demand field solution for Surveying,

Architecture, Engineering and Construction (AEC).

fieldPro works seamlessly together with Leica

Geosystems sensors, such as TPS, GPS and Leica

DISTO plus, allowing users to create and visualize

2D drawings or 3D CAD mod-

els of any site in real time.

With Leica fieldPro tasks can

be completed on site with no

site revisits or rework. Leica

fieldPro is a complete soft-

ware solution that works

directly in AutoCAD and other

Autodesk products. fieldPro

adds a set of menus and

toolbars to the user’s existing

AutoCAD toolset and uses

the familiar AutoCAD user

interface. Different options of

Leica fieldPro interface in real

time directly from CAD to

Leica Geosystems sensors,

such as the Leica DISTO plus

to create floor plans or any

other architectural as-built.

Leica Geosystems TPS and

GPS sensors can be used to

create 2D drawings or 3D models on site, or to

stakeout directly from the design CAD file in 2D or

3D.

Source: Leica GeosystemsInternet: www.leica-geosystems.com

Launch Leica fieldPro eSpatial and Laser-ScanOf fer SpatialTrust

Laser-Scan and eSpatial extend their existing collabo-

ration to jointly develop and promote SpatialTrust.

This combined product and services solution delivers

on the need for discovery, aggregation, quality assur-

ance and controlled dissemination of spatial data

assets. Built on the combined components of

iSMART5 and Radius Studio, the offering provides for

an Enterprise Class architecture underpinned by Oracle

Spatial and Oracle Application Server 10g.

The SpatialTrust solution enables the following key

activities:

• Discovery of available data across an enterprise;

• Access to data from source and transformation as

required;

• Aggregation of data sources into a usable format;

• Quality certification of the data including the pro-

cess of rule generation, automated & manual fix-

ing and ongoing conformance checks delivering

data quality certification;

• Controlled dissemination of the data to users and

applications.

Source: Laser-Scan and eSpatial

Internet: www.espatial.com/solutions_spatialtrust.html

and www.laserscan.com



Product News

3D Nature AnnouncesGoogle Earth KML Exporter

3D Nature introduced their new Google Earth KML

exporter for their Scene Express product. This new fea-

ture brings the company’s landscape-visualization tech-

nology to the realm of KML- compatible 3D Geographic

Exploration Systems like Google Earth and ESRI's

ArcGIS Explorer. Users can place roads, vegetation and

landcover, buildings, vehicles and structures to build a

comprehensive and detailed environment. Visual Nature

Studio makes creating still images and animated fly-

throughs a snap, and Scene Express' multi-format

exporter expands these abilities into the domains of

VRML, 3D Nature's NatureView Express and now KML

for Google Earth. Notable features of the KML exporter

include the ability to quickly and easily link rich text,

photos and web page links to objects in the 3D scene,

driven by GIS attribute data. This permits the rapid cre-

ation of huge environments with markers and other

entities that can be clicked upon to display information,

or even jump to a web site about the entity. The

Google Earth exporter is available now as a free update

for all current Scene Express 2 owners.

Source: 3D Nature

Internet: www.3DNature.com

PCI Geomatics and eSpatial jointly announce the

integration of PCI Geomatica Image Management

System (GIMS) with eSpatial iSMART. GIMS is an

enterprise-wide solution that can store, process, and

access geospatial data using PCI Geomatics, Oracle,

and eSpatial technology. GIMS enables the manage-

ment of image data or metadata, or both, in a

database and provides intelligent data loading, stor-

age and Web-based access solutions, which can

help increase the practicality, integrity, and accessi-

bility of image data.

Source: PCI GeomaticsInternet: www.pcigeomatics.com/solutions/geocapacity

Integrated Solution PCI Geomatics and eSpatial

Leica Geosystems Geospatial Imaging’s IMAGINE

Easytrace delivers efficient assisted feature extrac-

tion, driving efficiency throughout the vector feature

capture process by minimizing the number of

mouse clicks that a user must perform. When cap-

turing vector information from a digital source, such

as satellite imagery or aerial photography, tradition-

al ‘heads-up’ digitizing requires the user to place

vertices frequently along a road or land cover

boundary. The IMAGINE Easytrace add-on to IMAG-

INE Essentials expedites this process by employing

interactively placed seed points and then applying

an adaptive line fitting algorithm to accurately trace

the feature between the seed locations, reducing

the time needed to capture irregular linear and

polygonal features.

Source: Leica GeosystemsInternet: www.gi.leica-geosystems.com

IMAGINE Easytrace by Leica Geosystems

Geo-3D Inc. released a new version of its Trident-3D

Analyst data extraction software. Trident-3D Analyst

is a soft-copy photogrammetric tool for the analysis

of digital images captured with horizontally oriented

camera systems. Trident-3D Analyst has the capabili-

ty of working in static or temporal stereo-base

mode.

The new version includes the following features:

• 3D GIS viewer based on openGL;

• Improved OTF Calibration tool (possibility of

using control points);

• Support for Oracle ODBC linked layers.

Source: PCI GeomaticsInternet: www.pcigeomatics.com/solutions/geocapacity

Geo-3D Releases Trident-3DAnalyst Version 3.3

Manufactured for embedding into any device that

requires position specific information, the Jupiter 30

is an ultra-high sensitivity surface mount GPS

receiver designed for rapid position fixes in low sig-

nal strength conditions. The Jupiter 30 combines

TCXO, LNA, flash memory and other select high-

quality components with the latest integrated SiRF

GSC3 chipset into a package that is optimized for

the best RF tracking capabilities possible, and

delivers fast (less than one second) GPS acquisition

time-to-first-fix. The Jupiter 30 is compatible with

devices with wider operating voltage ranges and

that require greater noise rejection than other GPS

modules. The unit involves low-power operation

and full use of the SiRF GSC3 power level modes.

Its gain characteristics and optimized LNA and RF

signal path design enable integration into products

with active or passive GPS antennas. Further speci-

fications include 20-channel mode GPS support;

acquisition fix performance of <1 second (hot start),

32 seconds (warm start) and 34 seconds (cold

start); ephemeris tail and bit sync for quicker time

to fix in poor conditions and SiRFLoc multi-mode

GPS support for improved fix availability. The physi-

cal characteristics of the device are 25.4mm x

25.4mm x 3.0mm form factor and 4.0 grams in

weight based on an industry standard form factor

providing an easy upgrade path. The Navman

Jupiter 30 GPS module is available in sample quan-

tities, with full production volume available in April

2006.

Source: NavmanInternet: www.navman.com/oem/products/gps_receivers/jupiter_30

Jupiter 30 Ultra HighSensitivity GPS ModuleNavman

Leica Geosystems announced

the upcoming release of Leica

GradeSmart 3D (V5.2), a smart

machine automation dozer

and grader solution for the

construction industry. The

latest generation (V5.2) also

marks the introduction of the

new name Leica GradeSmart

3D (formally Leica GradeStar).

Leica GradeSmart 3D 5.2

includes a range of features

and developments which are

designed to improve the ease

of use of GradeSmart 3D. To facilitate this, version

5.2 will introduce new features and improvements

designed to enhance speed of operation, support

and usability. Key to the enhancements within Leica

GradeSmart 3D 5.2 is a streamlining of the data

transformation process. This is achieved with the

introduction of the Leica SiteSmart software range,

and Leica SiteSmart - Translator.

Source: Leica GeosystemsInternet: www.leica-geosystems.com

Leica Introduces GradeSmart 3D V 5.2


June 200664

Industry News

STAR INFORMATIC Receives Oracle Award STAR INFORMATIC has received the Oracle Spatial

Excellence Award for Partnership 2006 is in recogni-

tion of STAR INFORMATIC's contribution to the

development of the Oracle Spatial partner commu-

nity in EMEA, STAR’s position as a leading force in

creating a new and innovative community of Oracle

Spatial-based solutions and its success in deploy-

ing Oracle Spatial as part of its solutions broadly

throughout Europe and the Middle East. STAR

INFORMATIC is a Partner in the Oracle

PartnerNetwork.

www.star.be

Trimble Equips Second Polish GovernmentAgency with GPS TechnologyTrimble has supplied 271 GeoXT rugged GPS hand-

held receivers to Poland’s Plant Health and Seed

Inspection Services (PHSIS), a national government

agency. This purchase follows an earlier sale of 156

GeoExplorer units to Poland’s agency for

Restructuring and Modernization of Agriculture in

early 2005.

www.trimble.com.

Microsoft Acquires Vexcel Microsoft confirmed the acquisition of Vexcel. It is

Microsoft’s second deal in the past six months for

its Virtual Earth business unit. The purchase was

done to enhance the talent, technologies, products

and services dedicated to fulfilling Microsoft’s

broad vision for best-of-breed local search and

mapping solutions for consumers, businesses and

government. Vexcel employees become Microsoft

employees and will be part of Microsoft’s Virtual

Earth business unit.

www.vexcel.com

Distributor Partnership PCI Geomatics and TGISTechnologies PCI Geomatics signed a strategic distributor part-

nership with TGIS Technologies allowing PCI

Geomatics to market, distribute, and sell the TGIS

real-time GeoConferenceT Software. TGIS

Technologies, a Canadian owned and operated

business, built GeoConference to allow users to

hold Internet teleconferences based on multi-source

geospatial information. This solution allows groups

to capture, preserve, and reuse geographic informa-

tion, track and coordinate resources and interven-

tions, and transmit geospatial data in real-time for

effective, enterprise-wide decision making.

www.pcigeomatics.comwww.tgis.ca

Business Partnership Pictometry and LPASystems Pictometry and LPA Systems have formed a busi-

ness partnership. Under terms of the partnership

agreement, Pictometry will market a joint solution

that integrates LPA Eco-View infrared analysis soft-

ware with the company's professional GIS software.

The end result is an easy-to-use analytical tool for

improved environmental monitoring and planning.

www.pictometry.com

Trimble Acquires Assets of BitWyse Solutions Trimble has acquired the assets of privately-held

BitWyse Solutions, Inc. of Salem, Massachusetts in

an all-cash transaction. BitWyse is a data manage-

ment company specializing in 2D and 3D software

applications for engineering and construction plant

design. Financial terms were not disclosed. The

purchase of BitWyse’s assets is expected to extend

Trimble’s product portfolio of 3D laser scanning

solutions by providing application-specific software

capabilities within the Power, Process, and Plant

vertical markets. These markets are increasingly uti-

lizing laser scanning data to create ‘as-built’ draw-

ings, verify construction specifications and improve

productivity.

www.trimble.com

EMI Selects INPHO for 16 new PhotogrammetricSystemsEMI Harita Ltd with their headquarters in Istanbul,

Turkey, have selected INPHO software suite as the

new software platform for extending their digital

map production facilities. INPHO has recently deliv-

ered 16 photogrammetric systems to EMI, consist-

ing of production tools which include highly auto-

mated aerial triangulation (MATCH-AT), DTM

generation (MATCH-T; DTMaster), advanced 3D

mapping (Summit Evolution), as well as orthorecti-

fication (OrthoMaster) and fully automated color

balancing and image mosaicking (OrthoVista).

www.inpho.com

3-D Map Greater London from BlueSky

BlueSky announced a new 3D digital map of the

whole of Greater London. Captured using the LiDAR

distance measurement system, the aircraft-mounted

laser technology determines accurate heights of

land and buildings. The map is already proving to

be a valuable tool for flood mapping, terrorist

threat assessment and environmental modelling.

The digital data, which provides height above sea

level readings every metre with an accuracy of 15

centimetres, was created by Infoterra and is now

being made available commercially by BlueSky.

www.bluesky-world.com

GISFocus-Group Acquires KORDAB International ABGISFocus group announced the acquisition of

KORDAB International AB. The GISFocus-group,

mother company of ESRI Sweden, ESRI Finland,

LandFocus and Meldis, provides solutions for

improving organizations’ effectiveness with GIS

software which supports operations, planning, and

better decisions. KORDAB International, with the

product GEOSECMA, is a provider of information

systems for planning and facility management for

local government in Sweden but also with a market

position in Poland and Lithuania. GEOSECMA

compliments well the product portfolio of the

GISFocus-group.

www.gisfocus.se www.esri-sweden.comwww.kordab.se

Laser-Scan Scores in Indonesia Laser-Scan’s reseller for South East Asia, Credent

Technology, announces that Badan Pertanahan

Nasional (BPN) has purchased Radius Topology.

BPN Sub Directorate Mapping and Photogrammetry

is the national agency responsible for the provision

of spatial data to all local governments in

Indonesia. Credent will provide BPN with a soft-

ware solution that will automate the spatial data

cleaning process. Laser-Scan’s software will be the

spatial data quality component of the Oracle data

hub.

www.laser-scan.comwww.credent-asia.com

Eurimage Signs new Framework Supply Contractwith the ECEurimage has been awarded a framework supply

contract by the European Commission – Joint

Research Center (EC-JRC) for the provision of satel-

lite remote sensing data to European Institutions

Services over the coming years. The contract covers

world-wide data from QuickBird (and future

WorldView1), Landsat and ASTER satellites, to a

maximum of € 7 million (of which € 6 million for

QuickBird and WorldView1) for a total of 4 years.

Satellite data will be mainly provided for the

Commission’s agricultural Control with Remote

Sensing Campaign (CwRS), an operational project

Eurimage has been supporting since early the

nineties. Satellite data, and in particular world-wide

QuickBird very high resolution imagery, will be also

supplied to meet the Commission’s increasing

requirements in support of EU security and humani-

tarian aid programmes.

www.eurimage.com

East View Cartographic to Produce Maps ofAfghanistan's Uruzgan ProvinceEast View Cartographic has been contracted by the

Royal Netherlands Army Geographic Agency to pro-

duce new 1:50,000 scale topographic maps of

Uruzgan province in Afghanistan. The maps will ini-

tially support Dutch military deployments in the

region as responsibility for this province is handed

off from US troops. East View Cartographic was

selected for the project on the basis of its estab-

lished reputation as a trusted source for and pro-

ducer of worldwide topographic map products at

all scales.

www.cartographic.com

Eurolink Selects MapInfo Confirm The MapInfo Confirm infrastructure management

solution has been selected by Eurolink, a leading

European construction consortium to manage the

M4/M6 Kilcock to Kinnegad motorway, the first PPP

highways project in Ireland. The construction, oper-

ation and maintenance of the 27 year PPP contract

was undertaken by Eurolink at a cost of several

hundred million euros. The development comprises

a state-of-the-art highway covering 36km of motor-

way, 4km of standard duel carriageway, 17km of

side roads, six junctions and 36 significant struc-

tures (underpasses, over-bridges, river culverts etc).

www.mapinfo.com

Trimble to Acquire Eleven TechnologyTrimble has entered into a definitive agreement to

acquire Eleven Technology, Inc. of Cambridge,

Massachusetts in an all-cash transaction. Eleven

Technology is a mobile application software compa-

ny with a leading market and technology position

in the Consumer Packaged Goods (CPG) industry.

Closing of the transaction, anticipated before mid-

May, is subject to usual and customary closing con-

ditions. Financial terms were not disclosed.

www.trimble.com

Facts / Figures / Contracts


June 2006Latest News? Visit www.geoinformatics.com

Success for POLICE Applications from STARInformatic Eleven departments in Belgium are already

equipped with STAR Informatic’s new POLICE

solution. The application automatically produces

maps and plans of the incident with full symbology

and scaling tools. It also allows alternative routes

to be planned in case of serious incidents.

www.star.be

Applanix Chooses INPHO for DSS 322 AirborneDigital Sensor Data ProcessingApplanix has chosen the INPHO suite of software

tools as the recommended workflow to produce

directly georeferenced digital orthophoto products

with the Applanix DSS 322 digital aerial camera

solution. INPHO software provides DSS users with

a seamless, linear, and automatic process for trans-

forming digital aerial images into complete

orthorectified georeferenced data products. The

INPHO digital orthophoto production workflow in

conjunction with the Applanix DSS consists of an

automatic digital terrain model (DTM) from DSS

stereo pair generation environment MATCH-T), a

quality assurance and editing component for DTM

data (DTMaster Stereo), and an orthophoto produc-

tion and mosaicking module (OrthoMaster and

OrthoVista). When an existing DTM is available,

only the OrthoMaster and OrthoVista products are

required to produce full orthomosaic products.

www.applanix.com

OGC and IAI to Work Together The Open Geospatial Consortium (OGC) and the

International Alliance for Interoperability (IAI) signed

a memorandum of understanding to work together

to strengthen open standards based interoperabili-

ty between systems used by the building infrastruc-

ture community and the broader geospatial, archi-

tecture/engineering/construction (AEC) and

information technology (IT) communities. Initially,

the two organizations will assess member interest

in advancing the creation, testing, and implementa-

tion of open standards to improve the sharing of

XML based Industry Foundation Class XML (ifcXML-

IFC) building models and Geography Markup

Language (GML) geography models in the AEC and

geospatial user communities.

www.opengeospatial.org

GEODIS RO new Topcon Distributor in RomaniaTopcon Europe Positioning BV will transfer all its

positioning sales and support activities for

Romania to the newly-formed company GEODIS RO

S.R.L., a fully- owned subsidiary of Geodis Brno,

spol. s r.o., Topcon’s long-term partner. Geodis Brno

has been Topcon’s exclusive partner in the Czech

and Slovak Republics for over 15 years. It is the

leading supplier of positioning solutions and has

become one of Topcon’s major partners in Europe.

With this agreement, Topcon aims to provide its

customers with a strong basis for further expansion

of its sales and support capabilities for positioning

products in Romania.

www.topconeurope.com

Thales Signs Distribution Agreement for theUkraineThales Navigation signed a distribution agreement

for its land survey and GIS product distribution in

the Ukraine with Geomatics Solutions. Geomatics

Solutions will sell the Thales Z-Max and ProMark

land survey systems and the Thales MobileMapper

Pro and MobileMapper CE handheld GPS receivers

for geographic information system (GIS) and many

other data collection applications. Geomatics

Solutions is headquartered in Kiev, Ukraine.

www.geosolutions.com.uawww.thalesgroup.com/navigation

ER Mapper Brings Satellite Imagery to all ShellDesktopsER Mapper announced the rollout of a new soft-

ware solution for Shell Exploration and Production

that makes Shell's twelve terabyte archive of satel-

lite imagery available to users throughout the

world. The solution was built by ER Mapper's

Enterprise Services Team and features the Image

Web Server product, which uses patented image

compression and serving technologies to provide a

fast and responsive system, even when serving

very large images to many users. Using a web

browser, users simply zoom to a particular location

to see the list of images available for that area.

They can then ask for information about the

images, examine them, compare them with others,

and if desired, bring them directly into desktop

applications like ER Mapper's image processing

product, Microsoft Word or ESRI's ArcGIS product.

www.ermapper.com

Upgrade GE Mapping System to SmallworldSoftware for City of LeuvenGE Energy has upgraded the digital map system for

the city of Leuven, Belgium. GE Energy migrated

the G@lileo system to GE’s Smallworld 4 portfolio

of products including Smallworld Core Spatial

Technology, based on the new Application

Framework (SWAF) architecture, Smallworld Internet

Application Server (SIAS) and Smallworld Spatial

Intelligence (SSI) software.

www.ge.com/energy

Leica Geosystems Announces Acquisition ofScanlaserHexagon and Leica Geosystems announce the

acquisition of Scanlaser AB in Sweden and

Scanlaser AS in Norway. Scanlaser is a leading sys-

tem integrator for machine automation solutions in

Scandinavia and Poland. The companies provide

sales, assembly and support services for machine

automation systems for construction machines as

well as a wide range of stand-alone laser products

for the building and construction industry.

Scanlaser was already a long-time distribution part-

ner for Leica Geosystems’ GPS products, which the

company integrated into their high-end 3D machine

automation solutions. Scanlaser AB and Scanlaser

AS have a combined turnover of approximately 120

MSEK and over the last years have shown an aver-

age growth of about 35 percent per annum. The

companies’ results will be consolidated from 1 May

2006 and will immediately contribute to Hexagon’s

and Leica Geosystems’ earnings. The two compa-

nies will remain independent and will continue to

be managed by their respective management teams

who will directly report into the Group Sales Region

EMEA within Leica Geosystems. Scanlaser has 36

employees working out of nine locations in

Sweden, Norway and Poland.

www.leica-geosystems.com

European Space Imaging and EuropeanCommission Sign new Contract European Space Imaging (EUSI) has been awarded

a new framework contract for the supply of global

Very High Resolution (VHR) satellite imagery. The

contract was signed on April 5, 2006 and is valued

at 11.4 million EUR (14.5 million USD) over the next

four years. The imagery will be collected by the

IKONOS, OrbView and future GeoEye-1 satellites.

With this contract, European Space Imaging will

remain the European Commission’s largest provider

of VHR satellite imagery. The bulk of the imagery

will be received and processed at European Space

Imaging’s own satellite tasking and ground proces-

sing center at the German Aerospace Center’s

premises in Oberpfaffenhofen, just outside Munich.

From there, data is delivered to customers across

Europe minutes after collection using high-speed

fiber optic lines.

www.euspaceimaging.com

ER Mapper Appoints Guy Perkins as CEOER Mapper announced the appointment of Guy

Perkins as Chief Executive Officer (CEO) of ER

Mapper's global operations. Until recently, Perkins

was Vice-President of ER Mapper Asia-Pacific.

Perkins replaces Stuart Nixon who will continue

with ER Mapper as Founder and will concentrate on

strategic projects and deep research for the next

generation of imagery solutions. Perkins has held a

number of key leadership positions during his

career. A leading figure of the GIS community, Mr

Perkins has over 20 years of experience in the

Geospatial industry. He was involved with

Australia's Spatial Information Action Agenda and

was a founding Director of the Australian Spatial

Information Business Association (ASIBA). He

worked with ESRI Australia and ESRI South Asia for

15 years and later spent another 2 years with

MapInfo.

www.ermapper.com

Stan Moll Joins the DAT/EM SystemsInternational Sales Team

DAT/EM Systems

International wel-

comes Stan Moll to

its sales team. Moll

joins DAT/EM

Systems from

AeroMap U.S.,

where he served

for more than nine

years as the

Geographic

Information

Systems and

Remote Sensing

Program Manager. Moll has a Master’s degree in

Economic Geology and Remote Sensing from

Colorado State University, and a Bachelor’s degree

in Geology from the University of California, Santa

Barbara. Prior to joining AeroMap U.S. he was a

senior scientist with the US Geological Survey’s

EROS Data Center in South Dakota and Alaska.

www.datem.com

DAP Technologies Announces Sales andMarketing AppointmentsDAP Technologies enhanced its senior management

team with the appointment of Benoît Masson to

the position of Director of Marketing, and the pro-

motion of Brian Aldham to Director of Public Utility

Sales. DAP designs and manufactures computers

for a range of demanding industries including

Utilities, Field Service, Emergency Services, Public

Safety, Energy, Transportation and Logistics.

www.daptech.com

65

Industry News

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