Comparison of unfiltered CERES radiances measured from the S-NPP and Aqua satellites over matched sites

摘要

The focus of this paper is to introduce a novel strategy for comparison of unfiltered radiances in remote sensing devised for CERES scanners. The strategy is referred to as 'matched sites targeting', in which CERES instruments scan at nadir along their respective collocated ground-tracks. This strategy is enabled by similarities in the Suomi-NPP (FM5) and Aqua (FM3) satellite orbits, and a special scan profile available for the CERES scanners. Comparison of collected data in this strategy is done at a footprint level for a more stringent test of the consistency between the two instruments (FM5 and FM3) for specific scene types, as averages of 330 collocated nadir samples are compared. A comparison of comprehensive 'all-sky' measurements is also included as a reference. Results of the unfiltered radiance comparison are based on ES8 or ERBE-like data product using Edition-1 for FM5, and Edition-4 for FM3; cloud coverage is verified using MODIS data available in a SSF product.