[gdal-dev] increment in GMT output

Seb spluque at gmail.com
Wed Nov 4 17:36:27 EST 2009


I translated a HDF image:

$ gdalinfo asi-n6250-20020619-v5i.hdf 
Driver: HDF4Image/HDF4 Dataset
Files: asi-n6250-20020619-v5i.hdf
Size is 1216, 1792
Coordinate System is `'
  valid_range=0, 1
  long_name=ASI Ice Concentration, 20020619, res: 6.25000, AMSR-E, ASI Version: 5.5i, missing data interpolated.
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0, 1792.0)
Upper Right ( 1216.0,    0.0)
Lower Right ( 1216.0, 1792.0)
Center      (  608.0,  896.0)
Band 1 Block=1216x82 Type=Float32, ColorInterp=Gray

to GMT format with:

$ gdal_translate -of 'GMT' -a_srs 'EPSG:3411' asi-n6250-20020619-v5i.hdf asi-n6250-20020619-v5i.grd
Warning 6: A dataset opened by GDALOpenShared should have the same filename (asi-n6250-20020619-v5i.hdf) and description (HDF4_SDS:UNKNOWN:"asi-n6250-20020619-v5i.hdf":0)
Input file size is 1216, 1792

What is the warning about and how can I address it?

The output GMT grid is not valid because it has incorrect y spacing:

$ grdinfo asi-n6250-20020619-v5i.grd 
grdinfo: GMT ERROR: grid y increment <= 0.0
grdinfo: Use grdedit -A on your grid file to make region and increments compatible [asi-n6250-20020619-v5i.grd]
asi-n6250-20020619-v5i.grd: Title: 
asi-n6250-20020619-v5i.grd: Command: 
asi-n6250-20020619-v5i.grd: Remark: 
asi-n6250-20020619-v5i.grd: Pixel node registration used
asi-n6250-20020619-v5i.grd: Grid file format: cf (# 10) GMT netCDF format (float) (deprecated)                  
asi-n6250-20020619-v5i.grd: x_min: 0 x_max: 1216 x_inc: 1 name: meters nx: 1216
asi-n6250-20020619-v5i.grd: y_min: 1792 y_max: 0 y_inc: -1 name: meters ny: 1792
asi-n6250-20020619-v5i.grd: z_min: 0 z_max: 1 name: meters
asi-n6250-20020619-v5i.grd: scale_factor: 1 add_offset: 0

However, running `grdedit' as suggested didn't correct the problem, and
the program kept the -1 y increment.

Any pointers would be appreciated.  Thanks.



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