[gdal-dev] Warping EUMetsat MSG-4 MPE dataset to webmercator projection

[Even Rouault]

On jeudi 19 avril 2018 09:17:35 CEST Menno van Scheers - HUSS wrote:
> Hi,
> 
> Built version 2.2.4 of gdal with no additional libraries.
> Currently trying to warp a grib dataset to webmercator projection with the
> following arguments : gdalwarp  -t_srs "+proj=geos +lon_0=0 +h=35785831
> +x_0=0 +y_0=0 +a=6378140 +b=6356755 +units=m +no_defs" 
> 201804181115_L-000-MSG4__-MPEF________-MPEG_____-000000___-201804181115-__.
> grib webm.tiff
> 
> This task fails with : ERROR 1: Too many points (5625 out of 5625) failed to
> transform, unable to compute output bounds.
> 
> Source dataset has a geostationary projection
> Basic info on the dataset :
> 
> PROJ.4 string is:
> '+proj=geos +lon_0=0 +h=35785831 +x_0=0 +y_0=0 +a=6378140 +b=6356755
> +units=m +no_defs ' Origin =
> (-5570248.477582973428071,5570248.477582973428071)
> Pixel Size = (3000.403165948275728,-3000.403165948275728)
> Corner Coordinates:
> Upper Left  (-5570248.478, 5570248.478) ERROR 1: tolerance condition error
> 
> Lower Left  (-5570248.478,-5567248.074) ERROR 1: tolerance condition error
> 
> Upper Right ( 5567248.074, 5570248.478) ERROR 1: tolerance condition error
> 
> Lower Right ( 5567248.074,-5567248.074) ERROR 1: tolerance condition error
> 
> 
> Example of the dataset :
> https://hussbv-my.sharepoint.com/:u:/g/personal/menno_huss_nl/EQwTxBKwPQlOjP
> Z_DZcuZWcBgBs0y96_9Vev3tIqnne3KA?e=k6hmYU

Menno,

Yes gdalwarp has a hard-time with such images since a lot of points in them correspond to 
points not on the Earth surface...
The workaround is to explicitly specify the target extent (in the target SRS), so for full world 
coverage:
-te -20037508.34 -20037508.34 20037508.34 20037508.34

(note that the source image you mention appears to be fully black)

Even

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