| In this work we develop an algorithm for determining spatial parameters of an underwater source (such as bearing and depth), using passive sonar. In particular, we seek to localize the source in velocity. This can be done using conventional Doppler processing with an active sonar system. However, with a passive system, it is complicated by the introduction of random amplitude modulation on the time series, due to the broadband nature of the source, when one is performing narrow-band processing on a broad-band source. We seek to circumvent this problem by estimating the relative phase between modes of propagation, rather than their absolute phase. We develop a method that is computationally simpler and requires low signal-to-noise ratio in comparison with earlier approaches. |
