Inter calibrating geostationary imagers via polar orbiting high spectral resolution data

摘要

Geostationary Simultaneous Nadir Observations (GSNOs) are collected for Earth Observing System (EOS) Atmospheric InfraRed Sounder (AIRS) onboard Aqua and a global array of geostationary imagers. The imagers compared in this study are GOES-12 and METEOSAT-8. A single polar-orbiting satellite can be used to intercalibrate any number of geostationary imagers. Using a high spectral resolution sensor, in this case AIRS, with absolute calibration to within 0.1K in most bands brings this method closer to an absolute reckoning of Imager calibration accuracy based on laboratory measurements of the instrument's spectral response. The gap-filling method presented is an adequate method of compensating for AIRS spectral gaps in nearly all geostationary bands for comparisons done at or near the equator. The US Standard Atmosphere is adequate for the most part, but an atmosphere either calculated from an AIRS retrieval or one more suited to the environment in which comparisons are being made, could produce even better results.