[Gdal-dev] Data format

[Norman Vine]

Clay, Bruce
> 
> Norman:
>   Thanks for the update.  Do you know the difference in the data?  

yes but .......
http://edcsgs9.cr.usgs.gov/pub/data/srtm/SRTM30/SRTM30_Documentation
note that there are preconmputed 'difference' data sets available from the 
same place if you 'really' must know  :-)
 
> Do you know of any place to get free higher resolution data?  My other
> program needs better than 1 km spacing. 

Yes and no depending

Maybe you xhould spend some time reviewing the resources on Ben Discoe's 
excellent site
http://www.vterrain.org/Elevation/index.html
http://www.vterrain.org/Elevation/global.html

Note that FlightGear http://www.flightgear.org maintains a 'thinned'
version of an augmented SRTM data and a set of tools to build the 
global TIN that may or may not be of interest to you

'thinned' == data reduced to an irregular mesh representing a 'fitted'
surface that is within 'some' maximum error. I believe the currently
distributed version was created with a 20 meter maximum error, but
the tools allow this error to be set at data reduction time.

If you are interested in this the place to ask questions is on the 
TerraGear list  mailto:terragear-devel at flightgear.org

HTH

Norman