I have downloaded ASTER DEM tiles(n=400), I have to merge/mosaic them. While doing so I got a problem with one tile which does not merge but displays correctly.

I have downloaded it again but still I get the same problem. How can I mosaic it with others. I have seen such a question on this forum but it has not been answered. Link. The only properties it has different with others is that its uncompressed size is 0 bytes, no columns nor resolution. I have realized that the bad tile, one is able to view the attribute table while the rest one can not. The tile number is ASTGTM2_N30E041_dem.tif Image

  • 1
    GDAL and QGIS do not have any problems with this image.
    – user30184
    Jan 8, 2016 at 15:57
  • @user30184 confirmed, shows as 3601x3601, 1 band INT16, nodata unspecified
    – Steven Kay
    Jan 8, 2016 at 15:59
  • Does this mean its ArcMap that has a problem? Jan 8, 2016 at 16:13
  • How can I mosaic in QGIS? Jan 8, 2016 at 16:13
  • Integer overflowTraceback (most recent call last):File "C:\PROGRA~1\QGISPI~1\bin\gdal_merge.py", line 510, insys.exit(main())File "C:\PROGRA~1\QGISPI~1\bin\gdal_merge.py", line 496, in mainfi.copy_into( t_fh, band, band, nodata )File "C:\PROGRA~1\QGISPI~1\bin\gdal_merge.py", line 242, in copy_intonodata_arg )File "C:\PROGRA~1\QGISPI~1\bin\gdal_merge.py", line 75, in raster_copydata, t_xsize, t_ysize, t_band.DataType )File "C:\PROGRA~1\QGISPI~1\apps\Python27\lib\site-packages\osgeo\gdal.py", line 1051, in WriteRasterreturn _gdal.Band_WriteRaster(self, *args, **kwargs)TypeError: not a string Jan 9, 2016 at 7:05

2 Answers 2


This looks like an issue with ArcMap. I've been able to load this specific tile into QGIS, SAGA GIS and gvSIG without any problems (all of these use GDAL to open the raster)

QGIS does record the size correctly (3601 x 3601) and GDAL reports the pixel sizes...

Here's the gdalinfo output with metadata

$ gdalinfo ASTGTM2_N30E041_dem.tif 
Driver: GTiff/GeoTIFF
Files: ASTGTM2_N30E041_dem.tif
Size is 3601, 3601
Coordinate System is:
        SPHEROID["WGS 84",6378137,298.257223563,
Origin = (40.999861111111109,31.000138888888888)
Pixel Size = (0.000277777777778,-0.000277777777778)
  TIFFTAG_DATETIME=2011:03:15 19:52:13
  TIFFTAG_SOFTWARE=IDL 7.1.1, ITT Visual Information Solutions
Image Structure Metadata:
Corner Coordinates:
Upper Left  (  40.9998611,  31.0001389) ( 40d59'59.50"E, 31d 0' 0.50"N)
Lower Left  (  40.9998611,  29.9998611) ( 40d59'59.50"E, 29d59'59.50"N)
Upper Right (  42.0001389,  31.0001389) ( 42d 0' 0.50"E, 31d 0' 0.50"N)
Lower Right (  42.0001389,  29.9998611) ( 42d 0' 0.50"E, 29d59'59.50"N)
Center      (  41.5000000,  30.5000000) ( 41d30' 0.00"E, 30d30' 0.00"N)
Band 1 Block=3601x1 Type=Int16, ColorInterp=Gray

This answer covers how to use a VRT to mosaic images and has some useful links. Arc allegedly supports this format, but I'm not in a position to check this. You could use Merge, but according to my calculations this would give a 70k x 70k raster.

  • Using VRT to mosaic the images, still leaves the tile out Jan 9, 2016 at 7:03
  • I have realized that the bad tile, one is able to view the attribute table while the rest one can not Jan 9, 2016 at 7:26
  • 1
    I suggest to make a bug report through your ESRI contact.
    – user30184
    Jan 11, 2016 at 9:40

I have had exactly the same scenario with an ALOS (AW3D30) raster (tile N030E041). Using Mosaic to New Raster, this image was ignored. But using Mosaic, with the 'bad' image as the target worked fine.

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