[gdal-dev] Re: Strange things with gdalwarp ...

[Hermann Peifer]

Jukka wrote
> From: Hermann Peifer <peifer <at> gmx.eu>
> 
>> A promising approach seemed to be to warp/resample the ASTER files one by one and create 1500 separate tiles
>> in LAEA projection, as an intermediate step. Then I created a vrt file with gdalbuildvrt and
>> gdal_translated it into tiff format. The result did however look odd, as the elevation data in most tiles
>> was clipped by NODATA areas of their neighbouring tiles :-(
> 
> Hi, 
> 
> Did you try to use gdalwarp also for the second step with -srcnodata value [value...]?  I believe you did set some NODATA value in step 1 for the intermediate images.
> 
> -Jukka Rahkonen- 

I did. However, the main problem with gdalwarp is its performance. So my options seem to be:

1.
gdalwarping 1500 ASTER tiles in 1 run into a 4GB 100m raster output.tif
= 5-10 days processing (my best estimate)

2.
gdalwarping 1500 ASTER tiles 1-by-1 as an intermediate step, then
gdal_merge or gdal_translate to mosaic warped tiles into output.tif
= smaller or larger NODATA areas in output.tif, along tile borders

Today I resorted to Plan B, which is option A with a 250m raster output.tif. This is not exactly what I want to have, but seems to be doable in ~1 day.

Hermann