Correlation of underwater ambient noise

Abstract

The study of ambient n01se m the ocean has long been of interest to those involved in oceanography and naval research, as it relates to both underwater environmental processes and the performance of sonar systems. One of the more important aspects is the study of noise correlation between sensors, which is of particular interest because it can impart a directionality to the overall ambient noise field. Advanced sonar systems can be developed to take advantage of this directionality, filtering out waves exterior to the region of interest. This report summarizes the basic theory behind ambient noise correlation, and then develops from these basics various Monte Carlo simulation approaches of practical value. The final section discusses superdirective array processing, an advanced application of the preceding theory and simulations.