FM 92 GRIB is widely used to represent forecast and analysis products in
binary. The GRIB specification is maintained and reviewed by the World
Meteorological Organisation (WMO), through its Commission for Basic 
Systems (CBS) and Working Group on Data Management.
The WMO make available the specifications of binary representation forms
such as GRIB within the publication WMO - No. 306 Manual on Codes,
Volume 1, International Codes, Part B - Binary Codes.

Deutsches Klimarechenzentrum (DKRZ) provides software as source code
to process GRIB data provided by the IPCC DDC. The following is a 
description of "grbconv".

grbconv is a program that either lists the contents
of a GRIB file or converts GRIB records to binary or ASCII.

Compile with

 cc -O -o grbconv grbconv.c -lm
or
gcc -O -o grbconv grbconv.c -lm

Usage

grbconv -i input_file_name \
        -o output_file_name \
        -t output_type \
       [-d verbose ]

where

 input_file_name  is the GRIB input file name
 output_file_name is the output file name
 output_type      is either
   list - ASCII list of contents of input_file_name
   cona - ASCII output
   conb - binary output

   conb and cona give following structure of the output file

      header (1 record with 8 4-byte-integer)
      field  (1 record with n 4-byte-reals)
      header
      field
      and so on.
 
      the header consists of
          1. code number
          2. level
          3. date [yymmdd]
          4. hour
          5. nlon [or dim of spectral field, if encountered]
          6. nlat [or 1, if spectral field]
          7. DDC model ID
          8. Originating center ID
 
      so that the dimension of the data field is always given
      by header(5) * header(6).
 
In case of trouble feel free to call or send mail.
 
Good luck
 
------------- Deutsches Klimarechenzentrum GmbH ---------------
 
Arno Hellbach                      email: hellbach@dkrz.de
Deutsches Klimarechenzentrum       Tel +49 40 41173363         
Bundesstr. 55                      Fax +49 40 41173298         
D-20146 Hamburg
 
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