Measurements and Analysis of Reverberation and Clutter Data

摘要

This report describes the objectives and some of the results from a three-year joint collaboration between DRDC Atlantic and the Applied Research Laboratory of the Pennsylvania State University to analyze and model reverberation data. Reverberation data up to 4 kHz had been collected on towed arrays during the initial (1996-2002) NATO MILOC Rapid Environmental Assessment exercises and more recent JRPs (Joint Research Projects) between the US, Canada, and SACLANTCEN (now NURC, NATO Undersea Research Centre). Preliminary analysis and modeling of the data had been conducted, and reported at various conferences. For this project the data were analyzed and modeled in more detail, and the results reported in formal journal publications. Experiments were designed and conducted as part of a multi-ship trial in the Mediterranean in 2004, using arrays with directional sensors to perform left-right discrimination. A fast forward reverberation model was developed, suitable for inversion of environmental parameters in shallow water. Towed array beam patterns were incorporated, including the effects of directional sensors; results are presented showing the effects of cardioid and limacon sensors. The model has also been extended to model echoes from targets and scattering features; preliminary comparisons with data from 2004 have been made. Future work includes a follow on JRP and clutter experiment in 2007, and extensions to the model for quantitative analysis of clutter scattering strengths.