State of the Art and Future Trends in Geoinformatics

State of the Art and Future Trends in Geoinformatics

Gerhard Navratil

[email protected]

mailto:[email protected]

Gerhard Navratil 2/34

Contents

• How to determine State of the Art?

• GIS: The Early Years

• Framework Changes

• Changes in Research Questions

• Future Challenges


How to Determine State of the Art?How to Determine Future Trends?

• Look at industry solutions?

• Look at publications in journals?

• Look at presentations in conferences?

• Look at the development of knowledge!Try to extrapolate!


GIS: The Early Years

1960‘s: First Steps of GIS – Computers slow– Storage media slow and

expensive (tapes)– No graphical out put

Nixdorf 820, 1968 (Christian Giersing )


Early Maps

(Marble et al. 1984)


Early Topics

• Data storage

• Networks and topology

• Attribute modelling

• Required functionality

• User interface

• Graphical output


Example: Geometry

• Representation– Vector: Spaghetti, Topology (1980‘s)– Raster: Simple concept, easy to print, scanned maps

• Efficient storage– Databases save space (relational DB) (Codd 1969)

• Problems of data combination– Map algebra (Tomlin, 1990)

– Line intersection problem


Example: Line Intersection

• It Makes Me so Cross (Douglas, 1974)

– Task: General purpose FORTRAN routine to decide if two line segments intersect

– 5 pages of text, 21 special cases

• It Doesn‘t Make Me Nearly as Cross (Saalfeld,

1987)

– New representation (point-vector)

– determine r, r' – intersect if both in [0,1]

)''('''),( 010010 pprpLpprpL


What Happened?

Implementation led to problems

First solution

Improvement by different approach

More elegant solution

-improvements?


Framework Changes (80‘s/90‘s)

• Increasing amount of computing power (from exclusive equipment to ubiquitous infrastructure)

• Standard graphical user interfaces

GIS on standard office PC‘s


Problem: Data Supply

Main data sources:• Scanned maps (outdated)• Measurements (slow, expensive)• Satellite images (low resolution,

expensive)• Aerial photography (required digitizing,

expensive) Standard Data Suppliers (e.g., Ordnance

Survey)


Advantages of Standard Data Sources

• Well developed data capture processes known quality

• Clear understanding of the limits of the data

• (At least some) Liability issues solved


Disadvantages of Standard Data Sources

• Standard products with defined quality – only limited options

• Dependency on a single data provider

• Market power of producers Data quality discussed from producer perspective only


Software

Small number of commercial GIS:• ESRI• Intergraph• Siemens• MapInfo• (Erdas)Almost no independent products (mainly

GRASS and Spring)


Recent Changes

• New communication technology (Internet, mobile phones, WLAN)

• Abundant data:– Volunteered Geographic Information (VGI)– Satellite images– Laser Scanning/Digital Photogrammetry

• Software producing communities (open source software)


New Tools/Environments

• GNSS: Positioning information is availablehigh level of quality

• Smartphones (mobile, bi-directional access to data)

• Google Earth, Google Maps, Microsoft Bing


Changes in Research Questions

• Quality of the new data?

• Users are no experts Communication with lay people

• Data used during execution of a process, not during planning – changes?


Research Questions on Data (1)

• Understanding the processes that produce the data– Quality checks? Consistency? Updates?– Data processing steps?

• Understanding the communities providing the data– What is the incentive?– What is the task for which the data is needed?– Knowledge level of data producers?


Research Questions on Data (2)

• Limitations of the data set?– Scale of the data capture?– What is the quality? Is it uniform?

• Connection between different data sets?– Different communities collecting similar data

in the same region?– Similar communities collecting similar data in

neighbouring region?


Research Questions on Users

• What is the information needed by the user?– Required level of quality?– Required additional information?

• How to best communicate the information?– Graphical or Verbal or Oral?– User-oriented or as a map?– Level of redundancy?


Example: OpenStreetMap (1)

• Data provided by– Communities– Organizations (e.g., Ordnance Survey)– Private persons

• Data collected by– GPS-tracks– Digitizing aerial images

Teheran (OSM, 2011)



• Free to use (License: Creative Commons)

• Usable for routingand mapping

• Available forlarge parts of theworld Public Transport in Berlin (Melchior Moos, 2008)



• User tasks– Cartography (professionals/amateurs)– Navigation (routing)

• Assessing the quality is difficult– Attribute accuracy in international context?– Completeness?

In comparison to what? NAVTEQ/TeleAtlas-data?



Classification in different countries,e.g., highway = tertiary

(Wikipedia) (Wikipedia)(Google Earth)


Emerging Research Fields

• Semantics of data

• Assessment of data quality for VGI

• User interfaces

• Processes and time


Semantics of Data (1)

Data from different sources – what happens when we combine them?– Different communities use

different classifications – land cover vs. land use?

– Comparing apples andoranges?

(Comber, 2007)

(Wikipedia)


Semantics of Data (2)

Current tool: Ontologies

Research questions:

• Semantics of processes

• Vagueness

• Translation of terms between domains

• Trust in semantic quality of VGI


Assessment of Data Quality (1)

• Easy for result of single observation (quality of equipment)

• Difficult if– Data collected during extended period

e.g., land management– Data collected by vast number of people

e.g., VGI


Assessment of Data Quality (2)

Ideas for quality assessment in land management:

• Geometrical quality of cadastral boundaries: Compare data set with original surveys(Navratil et al. 2010)

• Compare the data sets with orthophotosResult:• Varying quality – how to communicate?• A: deviations between a few cm and 150m


User Interfaces

• New impulses for interfaces from Google Earth, smartphones, etc.How to exert this?

• How to exploit the new hardware?e.g., smartphones, tablets

• 2D or 3D? When to use what?

• Virtual reality or mixed reality? Applications? Benefits? Realization?


Processes and Time (1)

• Data are not static – reality changes constantly Data are connected to the date of collection

• Data describe/are influenced by processese.g., sensor networks

• Consistency checks require combination of processes and datae.g., differential equations (Hofer & Frank 2009)


Processes and Time (2)

Task are described by• Location• Duration• PrerequisitesCoordination of tasks requires• Start and end location of tasks• Duration of navigation between different

locations


Conclusions (1)

Finding research topics requires

• Understand the recent developments

• Detect changes in the framework

• Find the consequences of these changes

• Look for missing links


Conclusions (2)

Future key research topics are

• Semantics of data

• Assessment of data quality for VGI

• User interfaces

• Processes and time

State of the Art and Future Trends in Geoinformatics

Documents

Transcript of State of the Art and Future Trends in Geoinformatics