Thank you Even for your reply. I am actually not a professional gdal user, but looking at the thread that you posted I think the problem here is slightly different. Georegistration accuracy of gdalwarp result is perfectly fine, even better that MCTK result, and the bowtie effect is not present. I think it is a problem in resampling step that causes this artefact! Is that what you meant?
Regards Mohamad Even Rouault-2 wrote > Monobakht, > > Probably due to the bow-tie effect of the MODIS scanning sensor. gdalwarp > cannot currently deal with that correctly. > > Discussed recently in this thread: > http://osgeo-org.1560.x6.nabble.com/gdal-dev-gdalwarp-problems-with-MODIS-L1B-td5206583.html > > Best regards, > > Even > >> This question was posted originally at >> http://gis.stackexchange.com/questions/154959/strange-effect-in-gdalwarp-ou >> tput >> <http://gis.stackexchange.com/questions/154959/strange-effect-in-gdalwarp- > > output> but I did not get any helpful response. Here is the problem: >> >> I am using gdalwarp in python to extract and re-project reflectance bands >> from MODIS level 1B (MOD021km). The command that I am using is the >> following: >> >> / >> gdalwarp -of GTIFF -tps -t_srs EPSG:4326 -tr 0.01 0.01 -r bilinear >> -overwrite >> HDF4_EOS:EOS_SWATH:"C:\tmp\MYD021KM.A2007094.0935.006.2012075055042.hdf":MO >> DIS_SWATH_Type_L1B:EV_500_Aggr1km_RefSB C:\tmp\Output.tif >> / >> >> It converts the hdf subdataset without any problem but the output file >> seems to have some sort of artifact, specially close to the edges. (See >> below) >> <http://osgeo-org.1560.x6.nabble.com/file/n5216470/gdalwarp.jpg> >> >> I converted the same data using Modis Conversion Toolkit (MCTK) and it >> seems to be much better. (Below) >> <http://osgeo-org.1560.x6.nabble.com/file/n5216470/MCTK.jpg> >> >> I tried different resampling method and different output projection but >> still the same results! Is there anyone having this issue with gdalwarp? >> >> P.S. The data can be downloaded from this address: >> ftp://ladsweb.nascom.nasa.gov/allData/6/MYD021KM/2007/094/MYD021KM.A2007094 >> .0935.006.2012075055042.hdf >> >> >> >> -- >> View this message in context: >> http://osgeo-org.1560.x6.nabble.com/Strange-effect-in-gdalwarp-output-tp52 >> 16470.html Sent from the GDAL - Dev mailing list archive at Nabble.com. >> _______________________________________________ >> gdal-dev mailing list >> > [email protected] >> http://lists.osgeo.org/mailman/listinfo/gdal-dev > > -- > Spatialys - Geospatial professional services > http://www.spatialys.com > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Strange-effect-in-gdalwarp-output-tp5216470p5216483.html Sent from the GDAL - Dev mailing list archive at Nabble.com. _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
