Re: 980213: Some questions about gribtonc (fwd)

• To: bit-bucket@xxxxxxxxxxxxxxxx
• Subject: Re: 980213: Some questions about gribtonc (fwd)
• From: Robb Kambic <rkambic@xxxxxxxxxxxxxxxx>
• Date: Tue, 17 Feb 1998 10:39:31 -0700 (MST)

---------- Forwarded message ----------
Date: Tue, 17 Feb 1998 10:01:23 -0700
From: Russ Rew <russ@xxxxxxxxxxxxxxxx>
To: Jose Ignacio Lopez Chavarrias <nacho.lopez@xxxxxxxxxxxxxxxxxxxx>

cc: Roberto San Jose <roberto@xxxxxxxxx>
From: Jose Ignacio Lopez Chavarrias <nacho.lopez@xxxxxxxxxxxxxxxxxxxx>
Subject: Some questions about gribtonc
Organization: Laboratorio de Medio Ambiente
Keywords: 199802131652.JAA12752 gribtonc

Hi Jose,

I'm a student of the School-Technical University of Madrid, and I'm
trying to convert some GRIB files into some format recognized by MM5.
I've found your package, and I've compiled it, so now I've got an
executable called gribtonc.
I don't know if I didn't compiled it well, but I can't convert any grib
file. I've got some cdl examples that I've found in a web page, and I'm
trying to use them like cdl template, but always appears a "Memory
fault(core dumped), or something like that.
I'm working on a SP2. Can you tell me how I must work with gribtonc?.
And can you send a compiled version of this program?. I send you my
compiled version, for you to test it.

If you don't know how to solve my problem, or you are not the right
person, please tell me the email of someone who can help me.

Anticipated thanks.

- -- =============================================================

Jose Ignacio Lopez Chavarrias.
e-mail: nacho.lopez@xxxxxxxxxxxxxxxxxxxx
- --------------------------------------------------------------
       Environmental Software and Modelling Group
 Computer Science School-Technical University of Madrid (UPM)
 Ph: +34-1-336-7465               http://artico.lma.fi.upm.es

The gribtonc program (from the package
<ftp://ftp.unidata.ucar.edu/pub/decoders/decoders.tar.Z>) is not a
completely general-purpose GRIB decoder that will decode all GRIB files;
it was designed to decode the specific GRIB data that appears in the
U.S. National Weather Service's Family of Services High Resolution Data
Service (more details available from
<http://www.nws.noaa.gov/fospage.shtml>).  This includes some model
output data from U.S. NCEP models and some ECMWF model output, but it
may require some modifications for GRIB data from other sources.  It is
intended to be used with the CDL files that come with the Unidata
decoders package, in the directory decoders-2.3.4/src/gribtonc/cdl:

   avn-1.25x1.25.cdl  ecmf.cdl           ngm-g.cdl          sno.cdl
   avn-a.cdl          eta.cdl            ngm-q.cdl          sst-a.cdl
   avn-q.cdl          mrf-a.cdl          ocean.cdl          sst-t.cdl
   avn-x.cdl          mrf-e.cdl          ruc.cdl

An example of how gribtonc is invoked on a Unix system

  gribtonc avn-a.cdl outputfile < inputdata

where the input data is expected to be GRIB data with WMO headers that
identify each product.

Use with other CDL files may require modifications to the gribtonc
source code.  It's possible to create your own CDL files for gribtonc;
see <http://www.unidata.ucar.edu/glimpse/decoders/211> for a message
about this.

In contrast to gribtonc, the "gribdump" program that comes with the
Unidata Decoders package is more general, and should be able to decode
almost any GRIB file, with the exception of those that use second-order
packing.  However, gribdump outputs GRIB data in formatted text form,
rather than as a binary netCDF file.

I don't know of a completely general GRIB decoder that converts GRIB to
netCDF, although I do know of some other GRIB decoders:

 http://wesley.wwb.noaa.gov/wgrib.html

in C and some Fortran codes in

 ftp://ncardata.ucar.edu/libraries/grib/
 ftp://nic.fb4.noaa.gov/pub/nws/nmc/codes/

I have no access to the "SP2" platform you are using (is that IBM?), so
I can't create a suitable executable or do anything with the executable
you sent.  The decoders package comes with a built-in test that you can
execute with "make test" on Unix systems after the package is built.  If
that fails, we might be able to help by seeing the output from "make
test".


--Russ

_____________________________________________________________________

Russ Rew                                         UCAR Unidata Program
russ@xxxxxxxxxxxxxxxx                     http://www.unidata.ucar.edu