Passive broadband source localization using asynchronous vertically distributed hydrophones in deep water

This paper presents a method for passive broadband source localization using asynchronous vertically distributed hydrophones in a deep-water reliable acoustic path (RAP) environment. The proposed method utilizes the invariance of the striation frequency ratio with respect to the source depth to decouple range and depth estimation. First, the received spectra are resampled according to the striation frequency ratio and matched in pairs to estimate the source range. Then, based on the estimated source range, the source depth is estimated by using a modified Fourier transform. The proposed method outperforms the existing matching algorithm in terms of localization reliability when only a few hydrophones are available. The method also exhibits faster computation speed since it involves only one-dimensional grid scanning. Finally, experimental results in the western Pacific demonstrate that this method can effectively locate a submerged source at a depth of approximately 70 m.