A high-resolution underwater acoustic communication propagation simulator with multi-path transient sea-surface interactions

A channel simulation has been developed to explore the fine time-scale Doppler and multi-path arrival-time delay spreading imparted to underwater communication signals by interaction with the transient ocean surface. The simulation provides a configurable ocean test-bed for the purpose of testing and developing acoustic signal data coding and decoding strategies that are more reliable and resistant to the natural reverberation, arrival delay distortion and Doppler distortion that are inherent in relatively shallow underwater signal propagation. The simulator operates by calculating the transmit impulse response for successive realisations of a three-dimensional ocean surface with configurable sea and swell parameters. A unique transmit impulse response history is calculated for each of the underlying flat-surface ray-paths, capturing time-varying fluctuations of the rough surface around the mean-plane response. The realism of the synthetic multi-path channel response history is then evaluated against an experimental channel.