Operational Calibration of the Imagers and Sounders
on the GOES-8 and -9 Satellites, Page 2
Michael Weinreb, Michael Jamieson, Nancy Fulton, Yen Chen, Joy Xie Johnson,
James Bremer, Carl Smith, and Jeanette Baucom
ABSTRACT
The operational in-orbit calibration of the GOES-8 and -9 imagers and sounders is described. In the infrared channels,
the calibration is based on observations of space and an on-board blackbody. The calibration equation expresses radiance
as a quadratic in instrument output. To suppress noise in the blackbody
sequences, the calibration slopes are filtered. The calibration equation also
accounts for an unwanted variation of the reflectances of the instruments' scan
mirrors with east-west scan position, which was not discovered until the
instruments were in orbit. The visible channels are not calibrated, but the
observations are provided relative to the level of space and are normalized to
minimize east-west striping in the images. Users receive scaled radiances in
a GVAR (GOES VARiable format) data stream. The procedure users may apply to
transform GVAR counts to radiances, temperatures, and "mode-A" counts is
described.
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Contact Michael P. Weinreb at michael.weinreb@noaa.gov
Latest Revision: July 9, 1997
