[GRASS-user] TRMM (3B43) handling

[Markus Metz]

Markus Neteler wrote:
> Markus Metz wrote:
>> nikos wrote:
>>> hey list,
>>>
>>> Sorry that I took so much to respond,
>>>
>>> I'm orientating in a different direction right now, and I'd like an
>>> opinion (on TRMM 3B43 ofc).
>>>
>> Another option:
>> get binary grids from here
>> ftp://disc2.nascom.nasa.gov/data/TRMM/Gridded/3B43_V6/
>> read
>> ftp://disc2.nascom.nasa.gov/data/TRMM/Gridded/3B43_V6/3B43.ctl
>>
>> import into a latlon location with r.in.bin -f -b north=50 south=-50
>> east=180 west=-180 rows=400 cols=1440, e.g.
>> r.in.bin -f -b input=3B43.100101.6.precipitation.bin
>> output=3B43.100101.6.precipitation north=50 south=-50 east=180
>> west=-180 rows=400 cols=1440
>>
>> optionally convert mm/hr to some other time unit
>>
>> This can be easily scripted to automatically get and process the
>> complete TRMM 3B43_V6 dataset.
>
> Nice, written up as FAQ:
>  http://grass.osgeo.org/wiki/Import_TRMM
>
BTW, the TRMM 3B43 hdf files are really rotated 90° clockwise, north
is right and west is up.
The included datasets precipitation and error can be dumped from the
hdf files to a binary or ascii file with
the hdp tool which should be on any system that has the HDF4 library installed.
precipitation with
hdp dumpsds -r 4 -d -o <outfile> -b <TRMM 3B43 hdf file>
and error with
hdp dumpsds -r 5 -d -o <outfile> -b <TRMM 3B43 hdf file>

These are rotated and need to be rotated back. The (properly oriented)
binary grids are much easier to handle than the hdf files.

Markus M