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Re: Grib2-Data from the german weather service



Katja,

Your questions keep ending up in my spam box, Maybe you should try to use the support page at:

http://www.unidata.ucar.edu/support/index.html#process

send to: address@hidden


Here's an answer to part of your question, you can add both Grib1 and Grib2 parameters to the library. The documentation is at:

http://www.unidata.ucar.edu/software/netcdf-java/reference/GribTables.html

I downloaded the test file but I haven't looked at it  yet.

RObb...



On Tue, 15 Jun 2010, Moritz, Katja (LfU) wrote:

Hi Robb,

as you suggested i now use the netcdf-java-package for reading grib-data and it 
already worked fine for some data from ECMWF.
Now i want to process data from the local model of the german weather service 
in Grib2. With this data i have two problems: there are some parameters that 
are not included in the common grib-tables. Is it possible to add some 
parameters to the table before reading in the data?
Second: the interpretation of the grid-coordinates is not correct. The result shoud be 
longitude (max/min: 63.4678/-34.2451) and latitude (max/min: 70.9998/26.1229) and it is 
longitude (max/min: 342/383.5) and latitude (max/min: -20/21). It looks like these are still 
the rotated coordinates and that 360° should be subtracted from the longitude. Do i have 
to do the "unrotation" by myselfe or is the netcdf-package supposed to give the 
unrotated coordinates as a result?
If you would like to look at the file (COSMO_EU.grib2) - i put it on our 
website for download under http://www.hnd.bayern.de/login/daten/ (user: 
hnd-intern, pw: TaKaWaLaSt89). Thanks a lot already for your support!

Katja

-----Ursprüngliche Nachricht-----
Von: Robb Kambic [mailto:address@hidden]
Gesendet: Mittwoch, 10. Februar 2010 23:40
An: Moritz, Katja (LfU)
Cc: decoders
Betreff: Re: Grib2-Decoder

Katja,

Glad you found the problem, the grib package has been much work. If you
look at the netcdf-java page, you will see that it's integrated into that
package and then one doesn't have to deal with the details of grib.

RObb...


On Mon, 8 Feb 2010, Moritz, Katja (LfU) wrote:

Dear Mr. Kambic,

my name is Katja Moritz and i am working for the Bavarian Environment Agency in 
Munich, Germany at the Flood Information Centre.
Since the German Wether Service (DWD) will provide us in the future with 
grib2-data it is my task to process this data.
We already use some Java-Applications so it would be great, if we could use 
your Java-Decoder!
I already made a first attempt to read a testfile from the DWD (see 
attachement) and it worked out fine. Only the values i receive with the 
getData()-Method of the Grib2DataSection can't be correct - they are fare too 
negative. I already compared the values with the values i get with the 
C-program GRIB API (ECMWF). Those values looked ok.
What do you think is wrong with the data? Do i use your code correctly?

Many thanks in advance und many greetings from Munich!

Yours sincerely,
Katja Moritz

-----------------------------------
Dipl.-Hydr. Katja Moritz
Bayerisches Landesamt für Umwelt
Referat 88: Hochwassernachrichtenzentrale, Hochwasservorhersage Donau u. Inn
Lazarettstr. 67,
80636 München

Tel.: (089) 9214-1302
E-mail: address@hidden


===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================


===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================