GIS

The World at Your Fingertips

24 Oct, 2006 By: Kenneth Wong

Intermap Technologies maps Europe and the United States in 3D - with unexpected results


In the predawn hours, while most Londoners are sound asleep, fixed-wing airplanes equipped with IFSAR (Interferometric Synthetic Aperture Radar) methodically fly overhead at 30,000'. They traverse the airspace in tight strips, as if they were mowing a lawn. The pilots are not on a covert spy mission. They've been commissioned by Intermap Technologies, a geospatial solutions provider, to collect terrain data as part of a project to map Europe in 3D. What these planes are doing in the sky can potentially help drivers on the ground save fuel one day -- a result not even Intermap predicted.

Intermap's plan is to collect the geography of thirteen Western European countries by 2007 -- Austria, Belgium, Czech Republic, Denmark, France, Germany, Italy, Luxembourg, the Netherlands, Portugal, Spain, Switzerland and the United Kingdom -- as 3D elevation models. When the project is done, the Bavarian Alps, the Andalusian Mountains and the Rhine and Thames rivers will be merely a mouse-click away. Additionally, by the end of 2008, the company plans to complete U.S. data collection for its NEXTMap USA program.


After conquering Europe, Intermap will continue its geospatial data collection in Northern California and other U.S. regions.

All About IFSAR

IFSAR was developed by Environmental Research Institute of Michigan for the Defense Advanced Research Projects Agency. In February 1997, DoD (the Department of Defense) chose Intermap for the commercialization of IFSAR, in return for royalties on sales and preferred rates for DOD's use of the technology.

In published papers, the company explains its technology this way: "Topographic mapping from Interferometric SAR data is an accepted mapping technology. IFSAR for topographic mapping uses two apertures separated by a 'baseline' to image the surface. The phase difference between the apertures for each image point, along with the range and knowledge of the baseline, is used to infer the precise topographic height of the terrain being imaged."


An orthorectified radar image from Intermap's U.K. dataset.

"There's a tremendous amount of logistical challenges in how our data-acquisition teams undertake their missions," explains Eric DesRoche, Intermap's senior vice-president of business development. "When you're acquiring data over a heavily congested area, you have a lot of air-traffic issues. The advantage of our technology is that it's weather-independent and can operate at night, so for areas like Greater London, where there are lots of airplanes coming and going, the data collection takes place in the wee hours of the morning. The other challenge is wind or turbulence. If the aircraft is bouncing a lot, it's difficult for the engineers to filter out the movement data afterwards."

Intermap's fleet, which will be increased to five aircraft by the end of 2006, relies on onboard sensors, GPS units and inertial navigation units to collect the elevation data. "GPS is great at positioning you within the three-dimensional world -- in xyz coordinates and in latitudes and longitudes. When you integrate the inertial navigational units, you can now account for the dynamics of the aircrafts, their rolls and pitches. So that gives you the ability to determine the six degrees of freedom of the aircraft in space."

Flying Improves Driving

"When we first undertook the [European mapping] project, starting with Britain, we never thought of the automotive industry as an elevation-data consumer," admits DesRoche. That's because driving navigation has typically been associated with 2D maps, excluding elevation data. "We discovered that accurate road factors -- not only the horizontal data but also the slope and elevation data -- are in very high demand in automotive, because they can drive fuel efficiency. It has certainly been a very pleasant surprise."

Simply put, when a hybrid vehicle's mechanism is aware of the elevation data of the terrain, it can anticipate steep climbs and make informed decisions about when to alternate between fuel and electricity. Intermap's product in this arena is the NEXTMap series, which comprises elevation data from the United Kingdom to the United States to the South Pacific island nation of Vanuatu. (For a complete list of areas available, visit the Intermap store on its Web site.)

"Elevation data has a much longer shelf life than imagery of aerial photography," says DesRoche. "But the land masses do change, due to urban development and natural disasters." That's why the Intermap fleet is now flying over Britain once more, updating the information the company collected in early 2002 and late 2003.

Buy a City

Intermap's business partner CyberCity (not the same company as CYBERcity) will sell you a California county of your choice -- Los Angeles, Orange, San Diego, Sacramento and Ventura among them. The 3D city models are provided based on tiles -- 500 x 500 meters -- or based on districts. The digital orthophotos and the digital terrain models are provided based on tiles of 1,000 x 1,000 meters. Kevin Devito from CyberCity hopes these 3D city models will appeal to county GIS departments, regional governments and planning agencies. 

Intermap announced in September that each county, ranging in size from 945 to 4,752 square miles, will feature "aerial imagery draped over Intermap's elevation data that has a vertical accuracy of one meter or better. Users of the TerrainView software may select from a wide palette of environmental attributes, including time of day, skybox, distant haze, volumetric clouds, and rain, snow and wind effects, to generate realistic scenes within these counties. They will also have the ability to create and save flight paths, points of interest, and take 3D measurements of the displayed areas and features."


Based on Intermap's elevation data, CyberCity is providing navigable 3D cities.

Fly Over San Francisco

Using the same geospatial data that it supplies to high-end clients, Intermap is developing a consumer product: a DVD virtual tour of San Francisco. Set to launch later this year, the product is expected to sell for $30 to $50.

"It's completely interactive," explains DesRoche. "You load the DVD, and then you fly to any region of the city you want. We felt it would be attractive to people planning vacations and trips in the Bay Area." Based on the success of this San Francisco prototype, Intermap may launch other navigable DVDs of national parks; at press time, the company is chiseling out the digital terrains of Yosemite.


About the Author: Kenneth Wong


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