EVALUATION OF SENSITIVITY DECAY OF COASTAL ZONE COLOR SCANNER (CZCS) DETECTORS BY COMPARISON WITH INSITU NEAR-SURFACE RADIANCE MEASUREMENTS

Upwelling radiance and downwelling irradiance measurements were made at 0. 65 nm intervals in the 400-700 nm spectral range from an aircraft flown at an altitude of 150 m around 07. 30, 10. 06 and 11. 07 hours GMT. Each time the location was different and at each location the measurements were repeated three times. The NIMBUS-7 satellite overpass was at 10. 04 hours GMT. A comparison between the normalized water-leaving radiance retrieved from airborne measurements 910. 06 hours GMT) and from the CZCS data (10. 04 hours GMT) indicates that (i) the calibration slopes of 443 and 52 nm spectral channels should be slightly larger than those calculated according to H. R. Gordon et al. , whereas (ii) there is a converse indication for the 550 nm spectral channel.