[Gdal-dev] SRTM data and GDAL

[Vincent Schut]

Dear GDAL developers & users,

any news on a more sophisticated/automagicated way to open/convert SRTM data 
now South America is publicly available too?

Cheers,
Vincent.

On Friday 07 March 2003 10:43, Markus Neteler wrote:
> Dear GDAL users,
>
> since yesterday a SRTM shuttle elevation data are available
> for Northern America at around 90m resolution (0:00:03 deg):
>
> http://www.jpl.nasa.gov/srtm/cbanddataproducts.html
> ftp://srtm.usgs.gov/pub/data/srtm/North_America/3arcsec/
>
> The trick to use them with GDAL is as follows:
>
> - unpack the .zip file
> - mv NXXWYYY.hgt NXXWYYY.bil
> - create a .hdr file (ARC/INFO style) from the file name:
>
> Example for N18W077.bil
>
> BYTEORDER     M
> LAYOUT        BIL
> NROWS         1201
> NCOLS         1201
> NBANDS        1
> NBITS         16
> BANDROWBYTES  2402
> TOTALROWBYTES 2402
> BANDGAPBYTES  0
> NODATA        -32768
> ULXMAP        -76.9995833333        <- WYYY - 0.0004166667
> ULYMAP        19.00041666666667     <- NXX  + 1.0004166667
> XDIM          0.000833333333333
> YDIM          0.000833333333333
>
>
> Then gdalinfo then accepts the file and reports:
>
> gdalinfo -mm N18W077.bil
> Driver: EHdr/ESRI .hdr Labelled
> Size is 1201, 1201
> Coordinate System is '
> Origin = (-77.000000,19.000833)
> Pixel Size = (0.000833,-0.000833)
> Corner Coordinates:
> Upper Left  ( -77.0000000,  19.0008333)
> Lower Left  ( -77.0000000,  18.0000000)
> Upper Right ( -75.9991667,  19.0008333)
> Lower Right ( -75.9991667,  18.0000000)
> Center      ( -76.4995833,  18.5004167)
> Band 1 Block=1201x1 Type=Int16, ColorInterp=Undefined
>     Computed Min/Max=-10.000,2024.000
>   NoData Value=-32768
>
> Maybe the GDAL authors could add a simple HGT driver which
> automagically constructs the .hdr file internally on the fly.
>
> Anyway, with above method you can easily import/convert
> the data (also tested with GRASS).
>
> Cheers
>
>  Markus

-- 
______________________________________
Vincent Schut
Sarvision B.V.
Wageningen, The Netherlands
www.sarvision.com