AMSR-E data resampling with near-circular synthesized footprint shape and noise/resolution tradeoff study

An improved Backus-Gilbert resampling scheme is developed and applied on Advanced Microwave Scanning Radiometer-EOS (AMSR-E) brightness temperature swath data. The new resampling scheme has two improvements over the Special Sensor Microwave Imager and AMSR-E resampling schemes currently used to produce standard brightness products. First, the use of a circular Gaussian footprint as the reference footprint achieves near-circular synthesized footprints for all channels. The near-circular synthesized footprints diminish the effect of different orientations of the synthesized elliptical footprints produced by the standard algorithm. Second, a better synthesized footprint spatial resolution for the 6.925- and 10.65-GHz channels in the across scan direction is achieved with a significant reduction in noise level. Oversampling by AMSR-E at these frequencies enables this improvement.