A GOES-10/8 Imager Visible Channel Cross Calibration Procedure
Byron Raines
Raytheon Information Technology and Scientific Services
Lanham, Maryland 20706
Dan Tarpley
Climate Research and Applications Division, NOAA/NESDIS
Washington, D.C. 20233
The Geostationary Operational Environmental Satellite (GOES) series of meteorological
satellites do not employ an on-board calibration system for the visible channel data.
The post-launch sensor degradation is difficult to quantify and causes inaccuracy in
measurements derived from the visible band. Comparison of quantitative products from
different satellites of this series requires estimation and correction of the signal
deterioration. The National Environmental Satellite Data and Information Service
(NESDIS) now maintains coverage of North America from two GOES spacecraft, GOES-10 and
GOES-8, in fixed orbital geometry. The overlap in view from the two spacecraft now
exceeds a year of data coverage.
The dual east and west GOES viewing positions, with stable geometry, present the
opportunity to evaluate and correct the visible channel degradation of the two
satellites through a method of cross-comparison. The calibration estimates for both
GOES-10 and GOES-8, as derived from time and space coincident observations, are the focus
of this study. Scenes selected along the meridian midway between the spacecraft, and
taken near solar noon, provide a similar sun-target-sensor geometry from both views.
The individual visible channel deterioration rate estimates are derived for computing
measured albedos which are identical over the period of observation from the two GOES.
Several months of observations of the signal variation between the two platforms are studied
to form the basis for the derivations. The results provide a temporally-uniform
measure of the degradation rates of the two sensors that are used to correct the visible data.
![](images/flag.png)
![](images/blue_ribbon.png)