A two step linear statistical technique using leaps and bounds procedure for retrieval of geophysical parameters from microwave radiometric data

Abstract

A linear statistical technique using leaps and bounds procedure is developed for retrieving geophysical parameters from remote measurements. It is applied to the retrieval of sea surface temperature (SST) from the Scanning Multichannel Microwave Radiometer (SMMR) on the SEASAT Satellite. The technique involves the application of an efficient algorithm to select the best fixed-size subset, of the 10 SMMR channels for linearly retrieving a given geophysical parameter. The 5 channel subset [6.6 V, 6.6H, 10H, 18 V, 21H], where V and H refer to the vertical and horizontal polarizations, respectively and numbers are the channel frequencies in gigahertz, provides the minimum rms error in estimating SST. Comparison with ground truth indicates that the algorithm infers SST with an rms accuracy of better than 1.5K under most environmental conditions. A quality control procedure is proposed which should further improve the accuracy.