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. Abstract 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.