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Shuttle Radar Topography Mission Data

Posted by michael on from the land-navigation-made-easy dept.

SubtleNuance writes: "This story on Canada.com describes the mission and results of NASA's recent flight to map Earth. The Shuttle trip has provided the most detailed 3D photos of Earth ever released." Some of the images are just astounding. Too bad most of the data isn't available yet.

3 of 97 comments (clear)

  1. Contact your congresscritter by Zalgon+26+McGee · · Score: 4, Insightful
    Yet another reason to contact your congressman: ensure they vote for NASA appropriations.

    They aren't perfect, and more support for private enterprise in space is needed, but NASA is worthy of support.

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  2. Resolution? by Sawbones · · Score: 2, Insightful

    Other than "The map is going to be 100-times better than any other global map that we have," in the article there is no mention of how fine of detail the map goes into. Is it better than the 1 meter resolution of the (now defunct *sigh*) Terraserver?

    Still, cool tech.

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    1. Re:Resolution? by leeward · · Score: 2, Insightful

      Terraserver, and other systems that produce resolutions on the order of 1 meter, are photographic systems. SRTM is an imaging radar system, with resolution of 20-30 meters. And the key part of the phrase in your quote is "better than any global map".

      The primary job of SRTM was to generate a uniform global topographic map. There are other radar systems, such as geosar, which can get better resolution. But that is because they are mounted on airplanes, and are therefore flying much closer to their target. But you are unlikely see a global map from geosar, or any other airborne radar, because, well, the earth is just too big to cover it all in an airplane. And just trying flying a US military imaging radar on an airplane over China! They get grumpy enough about the spy planes flying off their coast. And yet SRTM made a world wide map in a single 10 day mission (except somehow they missed Area 51 - don't know how that happened).

      And the value of a uniform map is that there are maps around from literally hundreds of data sources, but maps of two different areas, made with two different data sets, are difficult to compare accurately without a uniform baseline to compare them against. SRTM data is intended to be that baseline.

      And finally, an advantages of radar data over photographic data is that it is difficult to get accurate topographic data from optical data. Also, you are at the mercy of the weather when obtaining photo data. The radar can see through clouds just fine.