FUNCTION precals(hostbl, satnum, ayear, aday, Kval, ocoeffs)
char *hostbl; long satnum; long ayear; long aday; float Kval[]; long ocoeffs[];
The host file name of the calibration degradation table.
The number of the satellite acquiring the pass (for example, 11 for NOAA-11).
The year of acquisition (ie. 94 for 1994).
The julian acquisition day.
The K value for AVHRR channels 1 and 2 of this satellite. These values are used to convert radiance to albedo.
The calibration coefficients for the AVHRR visual channels (channels 1 and 2).
For NOAA-06 satellite data, prelaunch calibration coefficient values will be returned (because NOAA-06 maintained nearly constant calibration over its lifespan). Otherwise, calibration coefficients will be computed from values retrieved from the degradation table.
precals() returns
E_SUCC --> Successful completion E_FAIL --> Operation failed