[gdal-dev] Strange effect in gdalwarp output

[Even Rouault]

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
> 
> 
> 
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