XCD Configuring Additional GRIB2 ADDE Datasets

Configuring Additional GRIB2 ADDE Datasets

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, then add these parameters to the ~mcidas/data/grib2NavLookup.txt file, use the DSSERVE command to add the dataset to your RESOLV.SRV file, and then stop and restart McIDAS-XCD for your changes to take effect.

From a McIDAS session as user mcidas, run the GRIB2NAV command to list the navigation parameters of the GRIB2 file.

Type: GRIB2NAV GRIB2Filename

where GRIB2Filename is the fully qualified path of a valid GRIB2 file on your system.

Example output is:

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

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, leave the dataset as is and do nothing, or change the DATAFILE=DESCRIPTOR option of the DSSERVE command in step 3 below to match the first column of the navigation entry.

If the navigation parameters do not exist in the ~mcidas/data/grib2NavLookup.txt file, then you will need to add them by logging in as user mcidas and updating the file. The format of this data file is as follows:

Column 1 is the filename prefix for the GRIB2 file created by McIDAS-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

Note: If you update the ~mcidas/data/grib2NavLookup.txt file, make a backup copy of the updated file so you can restore your local changes if the original file is overwritten (e.g., by installing a new version of McIDAS-X).

From a McIDAS session in the mcadde account, use the DSSERVE command to add the dataset to the RESOLV.SRV file.

Type: 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

DATABASE=mcrtgrib defines the database where the meta data is stored.

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.

Stop and restart McIDAS-XCD processing for your changes to the ~mcidas/data/grib2NavLookup.txt file to take effect in the database.