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Data format for GSI

The GSI can analyze many types of observational data, including conventional data, satellite radiance obervations (such as AIRS, IASI, SBUV/2 ozone, GOME ozone, GOES sounder, GOES imager, AVHRR), GPS radio occultation observations (bending angle or refractivity) and radar data. For use with the GSI, conventional observations are saved in the PREPBUFR format (BUFR format with NCEP specified features) and other data are saved in the starndard BUFR format. A list of the default observation file names used in the GSI is provided in the GSI Users' Guide (Version 2-Chapter 3: Running GSI).

Observation data in forms other than PREPBUFR/BUFR must be converted to PREPBUFR/BUFR before they can be used in the GSI.

Introduction and examples of how to decode and encode BUFR from NCEP: link

BUFR documents also can be found in NCAR DSS: link

PREPBUFR documents at NCEP: link

Observation data processing at NCEP (by Dennis Keyser): link

Data Hubs for PREPBUFR Data

The follow is a list of data center that has meteorological histroy data in PREPBUFR format :

• The NCAR CISL Research Data Archive (RDA):
  NCEP ADP Global Upper Air and Surface (PREPBUFR format) Weather Observations , May 1997 - Continuing
• NCEP public server: link
For Example: NAM products including observations available at: ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/nam/prod/