getting elevation data from mapserver

[Maarten Hilgenga]

Dear all,

I'm trying to output elevation data in dem format as described in the
WCS server example. The elevation data is in dted format (hgt file).
Since gdalinfo doesn't recognize this file as useable, I've used
global mapper to convert it to geotiff. The geoTiff is 1201x1201 and
has three bands:

Band 1 Block=1201x1 Type=Byte, ColorInterp=Red
Band 2 Block=1201x1 Type=Byte, ColorInterp=Green
Band 3 Block=1201x1 Type=Byte, ColorInterp=Blue

The output from mapserver is 800 x 600 and has three bands as well,

Band 1 Block=800x5 Type=Int16, ColorInterp=Gray
Band 2 Block=800x5 Type=Int16, ColorInterp=Undefined
Band 3 Block=800x5 Type=Int16, ColorInterp=Undefined

When I load the resulting file as geotiff into global mapper, I get a
black image. The height of the whole map is at least 1000m. Does
anyone know how to display this elevation data? Could it be that the
elevation is first converted to 8 bit and then to 16?

TIA, Maarten