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Ideas For Exploiting NASA's SRTM Data
MaxTardiveau writes with an excerpt from an article where the pictures are worth clicking through for: "Ten years ago, in February 2000, NASA mapped the entire world in eleven days. It's true: the mission was called the Shuttle Radar Topography Mission (SRTM), and over the course of eleven days, it used a big radar attached to the space shuttle to get elevation data from the vast majority of solid Earth; practically all land between 60 degrees North and 56 degrees South was included, with a resolution of 30 meters (90 feet). Over 9 terabytes of data were captured. It then took two years to process that data and make it usable (and it is still being refined to this day). This data is freely available to anyone, and the number of possible applications is almost infinite. It's been used in GIS, cartography, environmental planning, weather modeling (weather patterns are enormously influenced by the topography), flight simulators, Google Earth, and the list goes on. In this short article, I would like to give you a quick tour of the kinds of things this data can reveal. My hope is to get you thinking about what else could be done with this incredible resource."
The raw data, as well as data from multiple other sources can be downloaded from NASA's Earth Explorer http://edcsns17.cr.usgs.gov/EarthExplorer/. The article doesn't really address the fact that the Google data has been cleaned up a lot. SRTM has a lot of voids and areas of poor quality, especially over mountains. The resolution of the data is worse for anywhere outside of the USA.
According to Wikipedia, the 30-meter data is only available for the United States. The rest of the world will have to do with 90-meter data.
Actually it's lower resolution then many other maps, It does have very high coverage, The problem is trying to find a pass that doesn't have to much cloud cover. As someone who does GIS for a living, I can say we usually use this data til we can get a LIDAR Plane over the prospect.
It's just perfect use for games
Probably if you could find the data being talked about. Hard to imagine what I'm going to do with it if I don't have it!
On the Oregon Cost born and raised, On the beach is where I spent most of my days
OpenStreetMap uses this data to give the elevation contour lines on the cycle map rendering. Eventually, it'll be used to guide cyclists on a flatter, faster (but possibly slightly longer) route to avoid the steep stuff.
Furries make the internet go.
? ;)
A clunky UI and poor documentation appears to be an industry standard. You won't fix either of those problems going to a commercial package.
At most, one less than infinity! Duh!
Palm trees and 8
Take a look at Quantum GIS (http://www.qgis.org/), it's really good. It reads raw SRTM data directly, along with a huge list of other formats, raster and vector. It's free and it does a superb job. It's not ESRI, but it's excellent.
First, a quick reaction to your post. Radarsat-1 and 2 data, in regards to DEMs, is far from being comparable. The SRTM mission was dual-antenna interferometry, with Radarsat (or Envisat), you must use two images at different times. DEMs from Radarsat can be good and better than SRTM, but it's pretty expensive and there are alternatives (in Canada: CDED1 data is free and in many cases much more reliable than Radarsat data).
If you ever want to use SRTM-DEM data, check the CSI-CGIAR version 4 version. It's the best out there, it's a *major* improvement over the original and previous versions. If you're in hydrography, look at HydroSHEDS SRTM-DEM data.
This year, the advent of the ASTER-GDEM (global DEM) diminished the interest of SRTM-DEM. ASTER-GDEM is still "research-grade", but offers higher spatial resolution, and most important, cover much more land than SRTM (northerm Canada and URSS).
On top of my mind, don't forget SRTM-DEM is available at a higher spatial resolution over the USA than elsewhere (1 arc-second vs 3). The 1-arc-second for the whole world is suppose to become available some time in the future, but that has not happened yet. Also, the X-band (the actual SRTM-DEM comes from the C-band data IIRC) is in the hands of the Germans, but to my knowledge, no public DEMs has come out of it yet (even after all those years). Still relying on my memory (I can be mistaken, see next paragraph), the TerraSAR-X in orbit should be able to give us an even better near global DEM than what's available at the moment.
Sorry for the lack of links. I'm still in my holiday break and you can simply google your way in. Or search SRTM on the site in my sig! have fun -
Animoog.org
As a small indie video game developer NASA's srtm data was an invaluable resource for assembling an accurate map of ancient greece for our upcoming rts Hegemony: Philip of Macedon.