Multipath-based passive source range localization with a single hydrophone in deep ocean

This paper presents a single-hydrophone based method for source range localization from information contained in the multipath propagation in the reliable acoustic path (RAP) environment. The time delays between the direct (D) and the surface-reflected (SR) arrivals are obtained from the autocorrelation of the received signal and are compared with the D-SR time delays predicted by the acoustic model. Because of the high bottom-reflection loss and uncertainty of bottom properties, only the D-SR time delays are robust information for source localization. If the source depth is assumed known, the D-SR time delays versus source range can be predicted by the acoustic model. Reliable source track is then given through a family of measurements of the estimated source range during a period of time. Experimental data from a sea trial in South China Sea show that a sound source emitting 700-1500 Hz LFM sweeps could effectively be located within a range of 13km. The proposed method may be of advantage to source localization due to its simplicity.