On 11/30/2010 10:21 PM, ssobieraj wrote:
Hello,
I'm trying to use FWTools to transform from an arbitrary Datum/Projection
pair in an arbitrary format into a Geographic (lat/lon) projection with the
WGS84 ellipsoid in GeoTiff format.
To do this, I've tried the following:
gdalwarp -s_srs Input.prj -t_srs Output.prj Input.xyz Output.tif
Where Input.prj is formatted in Well-Known-Text format and contains
information specifically for the Input.xyz file.
Output.prj is also in WKT format but contains the following:
GEOGCS["Geographic Coordinate
System",DATUM["WGS84",SPHEROID["WGS84",6378137,298.257223560493]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]]
***
I've been successful in using this set-up for transforming from UTM
projection in WGS84 datum, but I am having trouble transforming from
Sinusoidal projection in RT90 datum. The output file is no longer skewed in
the Sinusoidal projection, but I cannot seem to get the datum information to
coincide, resulting in a 10+ km discrepancy.
A copy of the WKT-formatted PRJ file is seen below:
PROJCS["Sinusoidal",GEOGCS["Geographic Coordinate
System",DATUM["RT90",SPHEROID["Bessel
1841",6377397.155,299.1528131060786]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]],PROJECTION["Sinusoidal"],PARAMETER["central_meridian",0],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["Meter",1]]
Any ideas as to why I would be experiencing this offset?
Regards,
Scott
Scott,
it is not exactly what you ask, but it might help you in the right
direction: to convert modis sinusoidal rasters with a custom sphere to
wgs84 latlon, I use the following line (in a bash script):
gdalwarp -s_srs '+proj=sinu +R=6371007.181 +nadgri...@null +wktext'
-t_srs EPSG:4326 -srcnodata 0 -dstnodata 0 -r cubic -co "TILED=YES" -co
"TFW=YES" ${INFILE} ${OUTFILE}
(Note that I use proj notation instead of wkt formatting, I would not
know how to translate this into wkt).
Best,
Vincent.
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