A MULTI-BAND SEA SURFACE TEMPERATURE INFRARED RADIOMETER

RECENT RESEARCH HAS SHOWN THE IMPORTANCE OF CALIBRATING AND VERIFYING SATELLITE SEA-SURFACE-TEMPERATURE (SST) RADIOMETERS USING SHIPBOARD "SKIN" RADIOMETRIC THERMOMETERS RATHER THAN BUOY, IN-SITU THERMOMETERS. SINCE THE SATELLITE RADIOMETERS MEASURE SEA-SURFACE SKIN BRIGHTNESS TEMPERATURE, VERIFICATION SENSORS SHOULD MEASURE THE IDENTICAL SKIN TEMPERATURE TO ACHIEVE OPTIMUM SATELLITE RADIOMETER ACCURACY. BULK AND SKIN SSTS CAN DIFFER BY AS MUCH AS 2 DEGREES CENTIGRADE, WITH THE SKIN TEMPERATURE TYPICALLY 0.6 DEGREES CENTIGRADE COOLER THAN THE BULK TEMPERATURE. A 5-BAND, SHIP-MOUNTED, DOWN-LOOKING INFRARED RADIOMETRIC CALIBRATOR WILL BE DEVISED TO MEASURE SEA SURFACE BRIGHTNESS-TEMPERATURE TO WITHIN 0.02 DEGREES CENTIGRADE. IT IS AN EVOLUTIONARY EXTENSION OF AN EXISTING 4.25-3.7MUM AIRBORNE RADIOMETER. THE SST RADIOMETER WILL BE USED FOR SEA TRUTH CALIBRATION/VERIFICATION OF THE EXISTING AND PLANNED SATELLITE SEA-VIEWING RADIOMETERS. THE RADIOMETRIC CALIBRATOR IS AN IMPROVEMENT OVER CURRENT SENSORS IN THAT IT HAS VERY HIGH (0.02 DEGREES CENTIGRADE) THEORETICAL PRECISION, ACHIEVES NBS INTERCOMPARISON TRACEABILITY IN THE FIELD THROUGH A SEAWATER BUCKET CALIBRATION STANDARD AND TWO INTERNAL BLACKBODIES, AND IS DESIGNED TO USE 5 CHANNELS THAT MATCH EXACTLY THE CHANNEL PARAMETERS OF THE PLANNED MODERATE-RESOLUTION IMAGING SPECTROMETER-NADIR (MODIS-N) SST RADIOMETER SOON TO FLY ON THE EOS SATELLITE. RECENT RESEARCH HAS SHOWN THE IMPORTANCE OF CALIBRATING AND VERIFYING SATELLITE SEA-SURFACE-TEMPERATURE (SST) RADIOMETERS USING SHIPBOARD "SKIN" RADIOMETRIC THERMOMETERS RATHER THAN BUOY, IN-SITU THERMOMETERS. SINCE THE SATELLITE RADIOMETERS MEASURE SEA-SURFACE SKIN BRIGHTNESS TEMPERATURE, VERIFICATION SENSORS SHOULD MEASURE THE IDENTICAL SKIN TEMPERATURE TO ACHIEVE OPTIMUM SATELLITE RADIOMETER ACCURACY. BULK AND SKIN SSTS CAN DIFFER BY AS MUCH AS 2 DEGREES CENTIGRADE, WITH THE SKIN TEMPERATURE TYPICALLY 0.6 DEGREES CENTIGRADE COOLER THAN THE BULK TEMPERATURE. A 5-BAND, SHIP-MOUNTED, DOWN-LOOKING INFRARED RADIOMETRIC CALIBRATOR WILL BE DEVISED TO MEASURE SEA SURFACE BRIGHTNESS-TEMPERATURE TO WITHIN 0.02 DEGREES CENTIGRADE. IT IS AN EVOLUTIONARY EXTENSION OF AN EXISTING 4.25-3.7MUM AIRBORNE RADIOMETER. THE SST RADIOMETER WILL BE USED FOR SEA TRUTH CALIBRATION/VERIFICATION OF THE EXISTING AND PLANNED SATELLITE SEA-VIEWING RADIOMETERS. THE RADIOMETRIC CALIBRATOR IS AN IMPROVEMENT OVER CURRENT SENSORS IN THAT IT HAS VERY HIGH (0.02 DEGREES CENTIGRADE) THEORETICAL PRECISION, ACHIEVES NBS INTERCOMPARISON TRACEABILITY IN THE FIELD THROUGH A SEAWATER BUCKET CALIBRATION STANDARD AND TWO INTERNAL BLACKBODIES, AND IS DESIGNED TO USE 5 CHANNELS THAT MATCH EXACTLY THE CHANNEL PARAMETERS OF THE PLANNED MODERATE-RESOLUTION IMAGING SPECTROMETER-NADIR (MODIS-N) SST RADIOMETER SOON TO FLY ON THE EOS SATELLITE.