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GOES Variable(GVAR)

GVAR is the transmission of full resolution GOES N series data to ground stations within the footprint of NOAA's operational geostationary satellites GOES-13 (75W) and GOES-15 (135W), respectively. Dissemination schedules are maintained by NESDIS. With a geostationary orbit, any location within the satellite footprint is able to receive nearly continuous data coverage. To receive the data, users can purchase the necessary equipment (computer, software, antenna) from commercial companies for unlimited access to GOES signals. There is no fee or license requirement required by NOAA to receive this data. Archived data are available from NOAA through CLASS. Some commercial companies and other sites offer the data either processed or in raw form. Archived data acquired from NOAA usually incurs a fee for reproduction.

The GVAR data transmission format was developed to allow full use of the capabilities of the advanced, three-axis stabilized spacecraft while retaining as much commonality as possible with receiving equipment presently in use from earlier spin-stabilized GOES spacecraft. The GVAR format is based on the operational visible and infrared spin scan radiometer atmospheric sounder (VAS) mode AAA format, which consisted of a repeating sequence of 12 fixed-length equal size blocks. The transmission of these blocks was synchronized with the spin rate of the earlier GOES spacecraft, that is, one complete 12 block sequence per satellite rotation. The GVAR transmission sequence consists of 12 distinct blocks numbered 0 through 11. Blocks 0 through 10 are transmitted when an Imager scan line is completed. Block 10 is followed by a variable number of block 11s, according to what data are available for transmission.

View Information on the Conversion of GVAR Infrared Data to Scene Radiance or Temperature