AutoCreateWarpedVRT function creates incorrect VRT Dataset

[georges]

I noticed different behavior between gdal.AutoCreateWarpedVRT function from gdal_csharp.dll and gdalwarp command ran from command prompt. VRT dataset created with gdal.AutoCreateWarpedVRT function definitely outputs incorrect values, while those from gdalwarp are correct.

I am using Rhino5 application to generate a 3d mesh of the SRTM .tif topography model of Vesuvius. The .tif file is originally in WGS84 spatial reference system. What i do is create a new .tif file with projected reference system which uses Azimuthal Equidistant projection.

a) If I use the following gdalwarp command:

C:/gdalwin32-1.4.1/bin/gdalwarp.exe -s_srs EPSG:4326 -t_srs "+proj=aeqd +lat_0=40.81266 +lon_0=14.414252 +datum=WGS84 +units=m +no_defs" C:/vesuvius_wgs84.tif C:/vesuvius_aeqd.tif

And then open the new "vesuvius_aeqd.tif" file in Rhino5 application, everything is correct, and 3d mesh representation of the .tif file looks like this: ​https://www.dropbox.com/s/gr0r1bbin6osl30/vesuvius_gdalwarp.jpg?dl=0

b) However when I try to do the same thing, but with gdal C# libraries by calling the following functions through Rhino5 ironpython interpreter:

...
sourceSRS = osrc.SpatialReference("")
sourceSRS.ImportFromEPSG(4326)
targetSRS = osrc.SpatialReference("")
targetSRS.ImportFromProj4("+proj=aeqd +lat_0=40.81266 +lon_0=14.414252 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs")
num, datasetOutputSRS = outputSRS.ExportToWkt()
datasetWarped = gdal.AutoCreateWarpedVRT(dataset, datasetsourceSRS, datasetOutputSRS, gdal.ResampleAlg.GRA_NearestNeighbour, 0)
...

this is what I get: ​https://www.dropbox.com/s/on7sl66nce1cajt/vesuvius_AutoCreateWarpedVRT.jpg?dl=0

I also tried to replace the ImportFromProj4 function with SetFromUserInput function, and I still get the upper incorrect result. Looks like for some reason the AutoCreateWarpedVRT function creates an incorrect VRT dataset. Just to mention that if I use EPSG codes, then the newly created VRT dataset is valid, and looks the same as the one generated with gdalwarp command. For example, if I use the EPSG:32633, instead of the upper one which uses Azimuthal Equidistant projection:

...
targetSRS.ImportFromEPSG(32633)
...

in that case, the AutoCreateWarpedVRT function creates a correct VRT dataset, the same one that gdalwarp would create with:

C:/gdalwin32-1.4.1/bin/gdalwarp.exe -s_srs EPSG:4326 -t_srs EPSG:32633 C:/vesuvius_wgs84.tif C:/vesuvius_32633.tif

So something is definitely wrong with the way AutoCreateWarpedVRT function uses Azimuthal Equidistant projection.

The .tif file with WGS84 SRS can be downloaded from here: ​https://www.dropbox.com/s/tzp9any4e0lixox/vesuvius_wgs84.tif?dl=0

To call the gdalwarp from the command prompt, I am using ​gdal 1.4.1. As for the C# gdal libraries, I am using the ones from the release_1500_gdal_1.11.1_mapserver_6.4.1 as these were the last ones which supported Windows XP (I am currently using Windows XP SP3 and dotNET Framework 4.0).

I would welcome any kind of reply on this issue.

Thank you.