On 2011-03-17 15:34, Frank Warmerdam wrote:
On 11-03-17 05:09 AM, Wesley Roberts wrote:
Dear gdal'ers
I am working with TRMM rainfall data from an HDF5 file (converted
from hdf4
to hdf5). I am able to use gdal_translate to extract the gridded data
from
the HDF file using the following command.
gdal_translate -of GTiff
"HDF5:"3A25.071201.6A.h5"://DATA_GRANULE/PlanetaryGrid2/e_surfRainMean2"
test.tif
Gdal_translate works a treat and writes out the test.tif file perfectly,
however, the file is unreferenced and needs to be rotated by -90
degrees. Is
it possible to do this using gdal_translate or do I need to make use of
gdalwarp as well? My tiff world file needs to look something like this
0.500000 0.0000000 0.0000000 -0.500000 -179.750000 36.750000
Am I correct in assuming that a suitable proj4 statement might do the
trick,
wrt assigning projection info and defining rotation? If so can
someone point
me towards a document explaining the various proj4 declaration
parameters,
or give me some advice on how to go about getting the data properly
referenced.
Wesley,
I think the easiest approach is to prepare a worldfile representing the
current georeferencing in east-up or west-up orientation. Then use
gdalwarp to transform it to north up.
gdalwarp input.tif output.tif
For "east up" I think the world file might look something like:
0.0
0.5
0.5
0.0
top-left-x
top-left-y
You might need to fiddle around with the orientation a bit to get it
right.
Best regards,
But presumable the pixel sizes (1st & 4th) would not be zero?
--
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Zoltan Szecsei PrGISc [PGP0031]
Geograph (Pty) Ltd.
P.O. Box 7, Muizenberg 7950, South Africa.
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