Creating a GRIB2 Dataset

Adding a new GRIB2 dataset that accesses data in the MySQL database is a multi-step process.  You must first access the navigation parameters of the grib2 file, add these parameters to the ~mcidas/data/grib2NavLookup.txt file, use the DSSERVE command to add the dataset to your RESOLV.SRV file, stop and restart -XCD for your changes to take effect.

1. As user oper, run the grib2nav command to access the navigation parameters of the grib2 file.
   

   Type: grib2nav grib2Filename

   where grib2Filename is the fully qualified path of a valid GRIB-2 file on your system.
   
   Example output is:
   
   

   Nav parameters for message 66, field 0 are NAM, 6, -4564482, 2089981, 20318, 950000, 250000, 250000

   
   
2. If these navigation parameters do not exist in the ~mcidas/data/grib2NavLookup.txt file, then you will need to add them.  The format of this data file is as follows: 
   
   Column 1 is the filename prefix for the grib2 file created by -XCD (12 character maximum).  It is best if this is also the dataset descriptor name for the new dataset.
   
   Column 2 is the grid source name (4 character maximum)
   
   Column 3 is the projection type (1 and 4 are Mercator, 2 is Polar Stereographic, 6 is Lambert Conformal)
   
   Columns 4-9 are the navigation parameters calculated by the grib2nav command
   
   From the example above, the new navigation entry you should add to the ~mcidas/data/grib2NavLookup.txt file would be:
   
   

   NAM-USLCAW20 | NAM | 6 | -4564482 |2089981 | 20318 | 950000 | 250000 | 250000

   
   
3. If the navigation parameters already exist in the ~mcidas/data/grib2NavLookup.txt file, then you can either edit the first column to match your new dataset descriptor, or leave it as is. 
   
   
4. Use the DSSERVE command to add the dataset to the RESOLV.SRV file in the mcadde account.  
   
   DSSERVE ADD SAMPLE/NAM-USLCAW20 GRIB 1 999999 TYPE=GRID RT=Y INFO='''DATABASE=mcrtgrib DATAFILE=DESCRIPTOR GRIBTYPE=2''' "NAM - CONUS/LC; AWIPS 20 km
   
   DATAFILE=DESCRIPTOR indicates that this dataset will contain only the data files that match the descriptor name (in this case, NAM-USLCAW20* files).  If you have a different name in column 1 of your ~mcidas/data/grib2NavLookup.txt file, then you can include that name here in place of the word DESCRIPTOR.  GRIBTYPE=2 will only search for GRIB2 data files. 
   
   
5. Stop and restart -XCD for your changes to the ~mcidas/data/grib2NavLookup.txt file to take effect in the database.