Degradation Rates of the AVHRR Visible Channel for the NOAA 6, 7, and 9 Spacecraft

AVHRR channel 1 (0.57–0.69 µm) degradations were determined by comparing desert models with 68 months of observations of the Libyan Desert (20° to 30°N, 201 to 30°E). The comparisons revealed that the degradation rates were 0, 3.5% and 6.0% per year for NOAA 6, 7, and 9, respectively. An analysis based on zonal measurements covering half of Earth's surface suggests that thew rates are applicable to all surface types.