Near-surface source localization in the direct-arrival zone in deep water using a deep-located vector sensor

Abstract

Vector sensor has attracted extensive interests for its ability to simultaneously measure the particle velocity and the scalar acoustic pressure field, which has been widely studied in shallow-water acoustics. During a deep-water experiment held in 2014, a vector sensor located at the depth of 3146 m received the experimental signals launched by a towed transducer at 140 m depth. For the experimental environment, the arrival structure of sound rays and the arrival angles of the direct ray and the surface-reflected ray in the direct-arrival zone of a shallow source are analyzed. It is shown that the arrival angles of the direct ray and the surface-reflected ray vary greatly with range, and the variation of the shallow source’s depth has little influence on their mean arrival angle. Based on such properties, the arrival angles of the direct rays and the surface-reflected rays at the vector sensor are extracted from the experimental signals within the range of 10 km, and then the source ranges are estimated. Moreover, the source azimuths are also estimated with the experimental signals. Combining the estimated source azimuths and ranges, the source locations on the two-dimensional plane are determined. It is shown that the estimated source locations are consistent with the GPS measurements.