GRIB Grid File

GRIB is a WMO standard for grid transmission.  The gridpoint data is compressed to enable easier transmission. WXP handles most GRIB formats including all GRIB products from FOS, NOAAPORT and the NCEP NIC server.

FORMAT

The GRIB format is laid out into six sections:

1. Indicator block: the characters "GRIB" plus product size.
2. Product definition block: this block describes all data contained in the product
3. Grid definition block: this block describes in detail the layout of the grid (OPTIONAL)
4. Bit map block: this block is used to define where valid data is located is a sparse grid (OPTIONAL)
5. Binary data block: binary packed gridpoint data
6. End of record block: the characters "7777"

WXP can be used as a GRIB decoder by using either the griblook or grbcalc programs and saving the grid to a WXP ASCII grid file.  Programs like grbcalc and contour can be used to view the grids.

SEE ALSO

• griblook
• grbcalc
• contour

For further information about WXP, email technical-support@weather.unisys.com
Last updated by Dan Vietor on August 10, 1998