Explorations of in-situ passive source localization in the Philippine Sea using frequency-difference matched field processing

Abstract

Matched Field Processing (MFP) is a well-known technique for source localization in challenging acoustic environments. Accurate source localization using this method requires a correlation between array-recorded and replica acoustic fields calculated using knowledge of the acoustic environment. For a well-understood acoustic environment, this method is successful. However, recorded signals may be sensitive to details of the environment which are unknown and not included in the calculation of the replica field. The severity of this mismatch increases with frequency, as phase coherence is lost more easily at higher frequencies. In this case, a mismatch between the recorded and calculated fields will occur which can cause MFP to fail at relevant frequencies and ranges in the deep ocean. A proposed remedy to this problem may be analyzing the frequency-difference autoproduct of the measured acoustic field instead of analyzing the field itself. This presentation explores using this method to localize moored sou...