On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments

This paper outlines two calibration/validation efforts planned for current and future spaceborne microwave sounding instruments. First, the NPOESS Aircraft Sounder Testbed-Microwave (NAST-M) airborne sensor is used to directly validate the microwave radiometers (AMSU and MHS) on several operational satellites. Comparison results for underflights of the Aqua, NOAA, and MetOp-A satellites are shown. Second, a potential approach is presented for on-orbit field-of-view (FOV) calibration of the Advanced Technology Microwave Sounder (ATMS, to be launched in 2010). A constrained deconvolution technique is used to estimate spurious sidelobes in the ATMS antenna patterns from radiometric data collected while the sensor fields of view are scanned across the Earthpsilas limb.