[GRASS-user] MODIS HDF conversion in TIF tool.

[Ivan Shmakov]

>>>>> Hamish  <hamish_nospam at yahoo.com> writes:

 >>> Could the swath data be reprojected using gdalwarp's -tps thin
 >>> plate spline function? ISTR that's what -tps was commisioned
 >>> for. (??)

 >> I've tried gdalinfo(1) on AIRS .hdf:

 >> $ gdalinfo AIRS.2007.05.31.214.L2.RetStd.v4.0.9.102.D07281163221.hdf

 >> and it shows no ground control points.  I suppose, this is because
 >> the GCP's are given in separate HDF arrays (Latitude & Longitude),
 >> and not in the metadata.  Solving this problem may make gdalwarp(1)
 >> an alternative to HEG.

 > you can use gdal_translate to add (per scanline) GCPs to the metadata
 > before running gdalwarp.  gdal_translate -gcp pixel line easting
 > northing [elevation]

	Looks sensible.  Thanks!

 >> The one more problem with the MODIS L2 data is that it consists of
 >> overlapping scans -- MODIS could ``see'' some parts of the Earth in
 >> consequent scans.  Like this (intended to be viewed with a monospace
 >> font):

[...]

 > I think you may get a much better answer about this if you ask on the
 > gdal-dev mailing list. (www.gdal.org) Lots of smart experts on this
 > stuff there.

	ACK.

	Perhaps, breaking the input dataset into pieces corresponding to
	the instrument scans (e. g., 10 rows per MODIS scan at 1 km
	resolution), then warping them one by one will do the thing.  I
	have to check the GDAL API as well...