Where'd those lines come from? The technology behind Terrain View

Tuesday, May 12, 2009 | 3:49 PM

If you're a hiker, mountain biker, skier, or just a map enthusiast like me, you've probably checked out the Terrain View in Google Maps. Assuming your map view includes some geography with differences in elevation, you'll be treated to the linear splendor of closely spaced contour lines. For example, check out the differences in terrain data between the area around Tiny Town (Tiny Town, Colorado) and near Sterling (Sterling, Colorado). Your next question may be, where do we get that terrain data? Well, I'm glad you asked.

Most of the data comes from the Shuttle Radar Topography Mission (SRTM). From the SRTM website at http://www2.jpl.nasa.gov/srtm/ we learn that:

The Shuttle Radar Topography Mission (SRTM) obtained elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth. SRTM consisted of a specially modified radar system that flew onboard the Space Shuttle Endeavour during an 11-day mission in February of 2000. SRTM is an international project spearheaded by the National Geospatial-Intelligence Agency (NGA) and the National Aeronautics and Space Administration (NASA).
If you're looking for more detailed technical information on the SRTM program and data, you should definitely check out their website.

Maps Guide Adam