RE: Grib File

• To: Nelson Brandon K A1C AFWA/SCSA <brandon.nelson@xxxxxxxxxxx>
• Subject: RE: Grib File
• From: Robb Kambic <rkambic@xxxxxxxxxxxxxxxx>
• Date: Wed, 20 Jul 2005 15:28:52 -0600 (MDT)

On Wed, 20 Jul 2005, Nelson Brandon K A1C AFWA/SCSA wrote:

> Robb,
>
> The problem is I need to write a program that automates it.  This isn't a
> one time thing with a single grib file.  This is something we do with 100s
> of grib files every day!  Thanks again for your time!


Brandon,

the grib.jar api is just a level to decode the grib files, nj22 sits ontop
of it to do the work for specifc parameters based on their parameter
name/number, level type, and level. the nj22 code is available at:

http://my.unidata.ucar.edu/content/software/netcdf-java/index.html

the files used to handle the grib files is located at:
src/ucar/nc2/iosp/grib in the distribution. i would download the src for
2.2.10 and build it. run the toolUI program settng breakpoints in the src
to find the routines to perform the functions you are investigating.

robb...


>
> --Brandon
>
> -----Original Message-----
> From: Robb Kambic [mailto:rkambic@xxxxxxxxxxxxxxxxxxxxxxxx]
> Sent: Wednesday, July 20, 2005 12:27 PM
> To: Nelson Brandon K A1C AFWA/SCSA
> Cc: support-thredds; decoders
> Subject: RE: Grib File
>
> On Wed, 20 Jul 2005, Nelson Brandon K A1C AFWA/SCSA wrote:
>
> > Thanks again for your work Robb!  Basicly what I am trying to do is pull
> out
> > specifc parameters based on their parameter name/number, level type, and
> > level.
>
> Brandon,
>
> have you looked at that web start program? it does all the tasks that you
> mention and it will write out a file with only the desired paramters. i
> will see if there is some more doc on how to use it.  it's based on the
> java grib.jar that you been working with.
>
> robb...
>
>
>
>
> Could you point me in the right direction in your code on how I
> > might do this?  Things like Grib1LookUp look promising but there isn't
> > enough documentation (which is ok I know it's a beta ;)) for me to
> > understand it as I am relatively new to grib files.  Thanks for any
> further
> > help!
> >
> > V/r
> > Brandon
> >
> > -----Original Message-----
> > From: Robb Kambic [mailto:rkambic@xxxxxxxxxxxxxxxx]
> > Sent: Tuesday, July 19, 2005 3:20 PM
> > To: Nelson Brandon K A1C AFWA/SCSA
> > Cc: support-thredds; decoders
> > Subject: RE: Grib File
> >
> >
> > well, it looks like we did double the work. i also created a afwa.tab and
> > added it tothe  distribution. the new distribution is in the ftp decoders
> > directory. let me know if you run into any problems.
> >
> > robb...
> >
> >
> >
> > On Tue, 19 Jul 2005, Nelson Brandon K A1C AFWA/SCSA wrote:
> >
> > > I have updated your grib table with all of the ones you stated were
> > missing.
> > > Let me know when you put this into the build so I can check it out and
> see
> > > if there are anymore unknown parametes.  Also it is not Air Force Global
> > > Weather Center anymore.  We are called Air Force Weather Agency!
> > >
> > > Thanks a bunch again Robb!  Really been a help and I appreciate your
> time!
> > >
> > > --Brandon
> > >
> > > -----Original Message-----
> > > From: Robb Kambic [mailto:rkambic@xxxxxxxxxxxxxxxxxxxxxxxx]
> > > Sent: Monday, July 18, 2005 12:10 PM
> > > To: Nelson Brandon K A1C AFWA/SCSA
> > > Cc: support-thredds; decoders
> > > Subject: RE: Grib File
> > >
> > >
> > > Brandon,
> > >
> > > after viewing the data, i discovered many missing parameters. i couldn't
> > > find these on the web, do you know a location for a table?  or do you
> know
> > > the name, short desc, long desc, and units for the following parameter
> > > numbers.
> > >
> > > 134-137, 140-143, 145-149, 151, 152 155 157, 161, 163, 165-171, 191-194,
> > > 197, 199, 208, 209, 220-223, 227, 228, 230-239, 241, 246, 248-254
> > >
> > > robb...
> > >
> > >
> > >
> > >
> > >
> > > On Mon, 18 Jul 2005, Robb Kambic wrote:
> > >
> > > > 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/
==============================================================================