SECTOR FOCUSING FOR ROBUST HIGH RESOLUTION ANALYSIS OF THE MATCHED FIELD PROCESSING WORKSHOP DATA SET

Abstract

Replica correlator, minimum variance distortionless response, and sector-focused processing are applied to the test data cases devised for the Matched Field Processing Workshop. The methods are compared on this data set and their performance is clearly delineated. In all the cases examined from the workshop data set which were appropriate for the application of sector-focused procedures (i.e. the presence of mismatch together with modal noise), sector-focused processing performed successfully. It located the source with robustness similar to the replica correlator processor, but with the higher resolution characteristic of minimum variance distortionless response processing. In all cases where replica correlator localizes correctly, sector focusing also localizes correctly and achieves higher resolution. Sector focusing always reduced signal gain degradation compared to minimum variance distortionless response processing. It also reduced signal gain degradation compared to replica correlator processing for the lowest signal-to-noise ratio case. However, significant range bias error was observed in sector-focused as well as replica correlator processing in the case with general mismatch and colored noise. Sector focusing was not applied to the case with sound speed mismatch but no colored noise.