[Gdal-dev] srtm warping question

[Michael Heins]

listers;

Continuation of my SRTM reprojection problem.

I convert SRTM - BIL format into GeoTiff using Gdal_translate:
(so GeoTiff is in lat/long geographic coords)
gdal_translate -ot CInt16 -a_nodata -32768 c:\srtmtest\N43W071.bil c:\srtmtest\outll.tif

Then I reproject lat/long GeoTif into a utm projection GeoTiff:
gdalwarp -t_srs "+proj=utm +zone=11 +datum=WGS84" -ot CInt16 c:\srtmtest\outll.tif c:\srtmtest\oututm.tif

The resulting outll.tif is representative of the BIL in a grayscale representation.  This is as expected.
HOWEVER, the resulting oututm.tif is all null; when viewed, it is all black.??  why?
I have experimented with other sample tifs, and they seemed to be reprojected no problem.  This leads me to believe the Bil->Tif conversion is producing an errored Tif in some manner?

Can someone help me out with why this reprojection is not working?  does it have something todo with forcing the output type to 16bits?  And how can I go about to fix this?

Any help is appreciated; thanks,
-mike

 

 
________________________________________________________________
Sent via Aserty Enhanced Internet Services, Visit us at http://WWW.ASERTY.COM