Very long-range source localization with a small vertical array

Several processors are developed and used to perform source localization on the 3250-km San Diego-Hawaii path of the Acoustic Engineering Test (AET). Associated simulations an done to test the range-frequency limits of coherent matched-field processing using PE modeling through a simulated internal-wave environment. The AET experiment is presently well beyond the range of effective coherent matched-held processing. A mode filter was developed to extract 60 complex made amplitudes from the data received on the 20-element vertical line array. A mode space depth estimator successfully localizes the source. A mode arrival time difference range estimator is developed and found to be biased by internal-wave induced mode coupling. The final processor developed utilizes the stability of early arriving wavefronts to determine the source range by matching wavefront arrival patterns. (C) 1998 Acoustical Society of America. [S0001-4966(98)05809-3]