Perfect SRTM Project
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Some Usefull Links:

DG Void Killer -An utilitie to eliminate those nasty SRTM voids DGTV - A fine and User-Friendly freeware program to view and edit SRTM files. edcsgs9.cr.usgs.gov/ The Right Place to download SRTM files, connect using a FTP Client and go to the "pub/data/srtm/" folder and then select your region.





SRTM is a Powerful near-global digital elevation model (DEM) that results of the processing of the Data aquired using a sinthetic apperture RADAR from the Shuttle Radar Topography Mission, flown in February, 2000.
This process led to output beautifull data sets with 1arcsec (or 30m) horizontal resolution for the United States, and 3arcsec (90m) for the rest of the world. Both Distributions have a garanteed vertical precision of 10m.
Since the SRTM elevation data delivered to NIMA are unedited, they contain occasional voids, or gaps, where the terrain lay in the radar beam's shadow or in areas of extremely low radar backscatter, sutch as sea, dams, lakes and virtually any water covered surface that are flat but they don't look so flat on SRTM tiles.

One of the main problems are the voids:

VoidsNotClearmap.jpg (20784 bytes)

Voids are points of the SRTM data tiles that contain no data, this happens to bad radar scatter and on some places sutch as the Alps, shown on the picture above, the voids clearly disturb the terrain perception.

We developed a simple aplication to remove this voids by mixing SRTM and GTOPO30 data, here is the result:

VoidsClearmap.jpg (19387 bytes)

As you can see the result is surprisingly fine, althought the poorest resolution of GTOPO30 data set, the terrain perception is anyway realistic, as you can see on a 3D view of the same area:

VoidsClearLarge.jpg (44896 bytes)


For more details on this process, see DG-SRTM Void Killer Homepage or contact us

Here comes Perfeft SRTM Project, combining SRTM raster elevation data with several other data sets sutch as GTOPO30 and vectorial shore lines, rivers, lakes, etc. We are able to correct those errors.

 

On a 3D view of an estuary, the improvement is even more obvious:

We believe this technique would be quite usefull as fast and reliable way to get elevation data from around the world. SRTM Data Set is for example being adored by flight simulation enthusiast who now have more detailed landscapes to fly around. Specialy now that the Europe SRTM and Asia were finally released.

Download this Sample Here

More information Contact Us:
David Gil and Rui Nunes
By E-Mail or Mobile +351-91-832-5222