Spatial structure of temporal coherence for long range sound propagation in deep ocean with linear internal waves

The specific interference structure of sound field in deep ocean causes spatial fluctuations of temporal coherence whose study is of great significance for acoustic signals detection and processing. Here, the spatial characteristic of temporal coherence for long range sound propagation in deep ocean with linear internal waves is calculated and analyzed by Monte-Carlo simulations based on the parabolic equation method. Compared with previous study, the range and depth fluctuated characteristic of temporal coherence is demonstrated. The results show that spatial structures of temporal coherence are analogous to the interference patterns of sound field except at close receiving range, and the temporal coherence is much better for stronger interference field. Moreover, the spatial structure can be changed by frequency and sound speed standard deviation variations, where the changes for sound propagation along convergence zones with a shallow source are much more distinct than that along a deep sound channel.