RE: Grib File

• To: Nelson Brandon K A1C AFWA/SCSA <brandon.nelson@xxxxxxxxxxx>
• Subject: RE: Grib File
• From: Robb Kambic <rkambic@xxxxxxxxxxxxxxxx>
• Date: Mon, 18 Jul 2005 10:25:32 -0600 (MDT)

On Mon, 18 Jul 2005, Nelson Brandon K A1C AFWA/SCSA wrote:

> It works!  Thanks so much for your time Robb!  I am going to poke around in
> the Java files but could you get me a pointer (excuse the programming pun)
> in the right direction as how to pull out specific parameters from a grib
> file?  Thanks again!


Brandon,

you need to look at the index file, file ending with gbx. there a
explanation of the fields, etc in the IndexFormat.txt file in the root dir
of the distribution.   the important fields are: BmsOrGdsOffset
DecScale BmsExists.  the last 4 fields on the product line ignoring the -1
field.  for instance product line:

1 0 -1 11 107 0 255 0 2005-07-07T00:00:00Z 0 3495848078 46890 70206 1
false

then the Grib1GetData will grab the data:
java -Xmx256m ucar/grib/grib1/Grib1GetData data/us057g1010t04a000000000
46890 1 false

will return the temperature data in K.   the product name is from the 11
the 4th field from the table gwc_2.tab.

that's the hard way to extract the data.

we have a webstart program called netcdf tools at:
http://my.unidata.ucar.edu/content/software/netcdf-java/v2.2/webstart/index.html

a quick way to view the data would be to click the viewer tab and then
open the folder tab ( on the right side ) to select the data set to open.
this tools works with netcdf, grib, and other types of data. there's even
grid viewer if you select the grids tab, then open the dataset. there's a
red icon on the right to select. the tools program is a test program we
use, it's not really a product.

robb...

>
> -----Original Message-----
> From: Robb Kambic [mailto:rkambic@xxxxxxxxxxxxxxxx]
> Sent: Friday, July 15, 2005 4:45 PM
> To: Nelson Brandon K A1C AFWA/SCSA
> Cc: decoders; support-thredds
> Subject: RE: Grib File
>
> Brandon,
>
> are you sure you got the latest GribJava.tar.gz? the latest is:
> 711461 Jul 11 14:12 GribJava.tar.gz
>
> i ran the following w/o any exceptions thrown.
>
> % java -Xmx256m ucar/grib/GribChecker data/us057g1010t04a000000000
> % java -Xmx256m ucar/grib/grib1/Grib1Dump data/us057g1010t04a000000000 |
> more
> % java -Xmx256m ucar/grib/grib1/Grib1Indexer data/us057g1010t04a000000000
> | more
>
> remember the CLASSPATH must be set to find the grib.jar, jpeg2000.jar, and
> junit.jar.  if you still get exception let me know.
>
> robb...
>

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

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