Accuracy of passive source localization approaches with a single towed horizontal line-array in an ocean waveguide

Abstract

Instantaneous passive source localization applying the (1) synthetic aperture tracking, (2) array invariant, (3) bearings-only target motion analysis in modified polar coordinates via the extended Kalman filter, and (4) bearings-migration minimum mean-square error methods to measurements made on a single towed horizontal receiver array in a random range-dependent ocean waveguide are examined. These methods are employed to localize and track a vertical source array deployed in the far-field of a towed horizontal receiver array during the Gulf of Maine 2006 Experiment. The source transmitted intermittent broadband pulses in the 300-1200 Hz frequency range. All four methods are found to be comparable with averaged error of between 9% to 13% in estimating the mean source position in a wide variety of source-receiver geometries. In the case of a relatively stationary source, the synthetic aperture tracking outperforms the other three methods by a factor of two with only 4% error. For a moving source, the Kalman filter method yields the best performance with 8% error. The array invariant is the best approach for localizing sources within the endfire beam of the receiver array with less than 10% error.