UX 08.24.2007 HOW GEOGRAPHIC INFORMATION IS CHANGING DIGITAL MEDIA 1 Geolocation and Standards A...

08.24.2007 HOW GEOGRAPHIC INFORMATION IS CHANGING DIGITAL MEDIA 1UX

Geolocation and StandardsA Look at the Current State of Wayfinding


Conditions for Location AwarenessThe widespread adoption of location-aware services will depend upon the existence of three conditions: memory, connectivity, and standards.

memory connectivity

standards


Present State: Two Out of ThreeAt the moment we're close to the state of convergence, or networked geospatial intelligence. Most mobile devices have adequate memory and their connection to the net is sufficient …….The missing link is standards.

memory connectivity

standardsstandards

standardsstandards


How Devices are Found


Method 1: You Tell Us

For the current crop of mobile devices, there are three basic location finding schemes. The first is by far the simplest, and the most widely used at the moment. That is having the user -- the human agent -- identify the location.

Often the user will be asked for a street address or a ZIP code to retrieve information about a given location.

This method is accurate so long as the user knows where he is.


Method 2: Cellnet LocationEvery cell tower has the unique ID. When it is communicating with a mobile device, which also has a unique ID, that device can be placed within the tower's sphere of communication. Many 911 systems operate this way.

A more accurate method of determining location is cell tower triangulation. This spotting system uses three or more cell towers and by measuring signal strength relative to each tower, places the device at the intersection point of those spheres of communication.


Method 3: GPSThe third and most accurate method of determining location is GPS, or Global Positioning Systems .

• GPS depends upon a constellation of 24 medium-orbit satellites that transmit microwave signals back to earth.

• The primary GPS in use is NAVSTAR, which is funded by the US Department of Defense and maintained by the Air Force


How GPS WorksA GPS receiver calculates its position by measuring the distance between itself and three

or more GPS satellites. By determining the position of -- and distance to -- at least three satellites, the receiver can compute its position using trilateration.

With a fix on a fourth satellite, GPS receivers can also determine elevation above sea level.


Latitude and LongitudeTo measure location on the surface of the earth, global positioning systems use the

well-established standard of latitude and longitude.

The concept of latitude was understood by ancient sailors and by the 16th century latitude could be accurately measured with tools such as the backstaff or the sextant.

It wasn’t until the middle of the 18th century that longitude could be figured accurately by measuring time differences between a ship’s chronograph and time at the prime meridian in Greenwich, England.


Reading CoordinatesThe location of Razorfish’s office at 1440 Broadway is described in latitude and

longitude as: N40°45.267 W73°59.178’.

This means that we are located at 40 degrees, 45 minutes, and 27 seconds north of the equator and 73 degrees, 59 minutes and 18 seconds west of the meridian passing through Greenwich, England.

N 40° 45. 267 W 73° 59. 178

1 DEGREE 1 MINUTE 1 SECOND 70 miles 1 mile 100 feet


GPS LimitationsAlthough accurate to within a few meters, GPS requires a clear view of a

wide swath of sky. Tall buildings, dense undergrowth, even solar flares can interfere with GPS reception.


How Devices Share Information


Information SharingWhile the problem of location finding is mostly solved,

the issue of information sharing is not. There are competing standards in both communication networks and information networks that prevent location-aware devices from becoming a truly global phenomenon.

Most cell phones in the United States run on a CDMA (Code Division Multiple Access) network while most mobile phones in the rest of the world use GSM (Global System for Mobile communications). These two networks are not compatible.

GSM

CDMA


No Standard FormatIn a similar fashion, geospatial information is stored and communicated with a

multitude of different standards.

For example, Maptech and Garmin, two of the leading location-finding companies, record and transmit geospatial data in differing proprietary formats. Likewise, scientists working with bathymetric, orthographic and geodetic data have been using divergent content models to record their location-specific information.

EXIFGDA94ID3


Moving Toward StandardsThis Babel of languages and content models is slowly moving toward

interoperability and mutual intelligibility. The United States Geological Survey along with the International Standards Organization has endorsed SDTS, the Spatial Data Transfer Standard, and there are business groups like the OGC, or Open Geospatial Consortium advocating a standardized interchange of geodata in GML (a subset of XML), while the W3C has a working group devoted to semantic interoperability.


SGML and Its ChildrenPerhaps the best bet for interoperability will come from the 20-year old standard

ISO8879, which described SGML, or the Standard Generalized Markup Language.

On the web, XML (eXtensible Markup Language, which is a subset of SGML) has gained currency. XML is the basis for popular web services like those offered by Amazon and Yahoo, and it has spawned a host of specialized namespaces and schemas to handle geospatial information.

The best known of these geodescriptive metalanguages is KML, or keyhole markup language. KML is a version of XML that was developed by the Keyhole Corp., which Google bought in 2002 to build what is now Google Earth.


Convergence? Not Yet.Widespread adoption of these new tools and the shift to

standards-based interoperability will depend upon a really compelling economic driver, or a must-have application.

So far no such application has emerged to usher in the era of fluent intercommunication.

It seems, however, that it will just be a matter of time.


Contact

Rob Cummings,

Senior Information Architect,

Avenue A-Razorfish, 1440 Broadway, New York, NY 10018

212.798.6600

Also:

Rob Cummings,

Director,

Greenpoint Design,

1125 Lorimer St., Brooklyn, NY 11222

347.581.6359

www.greenpointdesign.com


Bibliography and References


References Articles· Do-It-Yourself Cartography, NYTimes.com, 12/11/2005:

http://www.nytimes.com/2005/12/11/magazine/11ideas1-13.html?ex=1291957200&en=1502e0b4ee25c734&ei=5090...· Google Zooms In Too Close for Some, NYTimes.com, 6/1/2007:

http://www.nytimes.com/2007/06/01/technology/01private.html?ex=1338350400&en=b7678075a3c97d28&ei=5124· With Tools on Web, Amateurs Reshape Mapmaking, NYTimes.com, 7/27/07,

http://www.nytimes.com/2007/07/27/technology/27maps.html?ex=1187928000&en=a8b134a3a2aba9a0&ei=5070· France Launches Maps Site, WIRED.com, 6/26/2006, http://www.wired.com/techbiz/it/news/2006/06/71234· Google Maps Is Changing the Way We See the World, WIRED.com, 6/26/2007,

http://www.wired.com/techbiz/it/magazine/15-07/ff_maps?currentPage=all· Mapping out a pathway to success, AM NY, 8/20/2007, http://www.amny.com/business/am-farn0820,0,2549876.story

Books· How Maps Work, Alan M. MacEachern,

http://www.amazon.com/How-Maps-Work-Representation-Visualization/dp/157230040X/ref=pd_bbs_sr_2/002-1469296-8338434?ie=UTF8&s=books&qid=1187817394&sr=1-2

· The Power of Maps, Denis Wood, http://www.amazon.com/Power-Maps-Denis-Wood/dp/0898624932/ref=pd_bbs_2/002-1469296-8338434?ie=UTF8&s=books&qid=1187817427&sr=1-2

· How to Lie with Maps, Mark Monmonier, http://www.amazon.com/How-Lie-Maps-Mark-Monmonier/dp/0226534219/ref=pd_bbs_sr_1/002-1469296-8338434?ie=UTF8&s=books&qid=1187817458&sr=1-1

·

Mapping sites· Maps.google.com· Maps.live.com· Maps.yahoo.com· Mapquest.com· mondomap.com· Multipmap.com· Hopstop.com


References Continued ...The United States Geological Survey (http://www.usgs.gov/ ) International Standards Organization (http://www.iso.org/iso/en/ISOOnline.frontpage OGC, or Open Geospatial Consortium (http://www.opengeospatial.org/ogc ) W3C working group devoted to semantic interoperability (http://www.w3.org/2005/Incubator/mmsem/wiki/FrontPage )Library of Congress, Maps -- http://memory.loc.gov/ammem/gmdhtml/gmdhome.htmlNASA’s Worldwind geobrowser: http://worldwind.arc.nasa.gov/The Map Room blog - http://www.mcwetboy.net/maproom/ Adam Greenfield’s blog (Everyware)- http://v-2.org/index.php GPS Visualizer, map your tracks - http://www.gpsvisualizer.com/MAKE, track your friends - http://www.makezine.com/blog/archive/2005/10/diy_gps_tracking.htmlNational Atlas, for Lat-Lon info - http://nationalatlas.gov/articles/mapping/a_latlong.htmlNew York Times, July 19, 2007. Basics, Global Positioning by Cellphone. By LARRY MAGIDGPS on How Stuff Works - http://electronics.howstuffworks.com/gps-phone.htmHow Stuff Works, Location Tracking - http://people.howstuffworks.com/location-tracking.htmNYT, June 10, 2007 Practical Traveler | Sharing Photographs Online Snapshots That Do More Than Bore Friends By

MICHELLE HIGGINSPC Today, Luxury GPS, April 2007 – www.pctoday.comWired Magazine, July 2007, The Whole Earth Cataloged - http://www.wired.com/techbiz/it/magazine/15-07/ff_mapsThe Space-Age Sailor, Good Old Boat, July-August 2007, www.goodoldboat.com

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