Wide-band shallow acoustic channel simulation with realistic Doppler and delay spreading for 3D evolving rough surfaces

A phase-coherent shallow underwater multipath channel simulation is described that combines the eigenpath amplitude/delay responses from a ray-tracing model for the flat-surface channel geometry, with the time-varying micro-path responses derived from signal interactions with successive 3D realisations of the rough surface. The time-varying rough surface response is calculated from a discrete series of time-circular 3D rough surface realisations, allowing the resulting time-circular channel impulse response to be used with test signals of arbitrary length. The simulated channel is synthetically probed to present comparisons of Doppler and delay spreading characteristics of measured and simulated replica channels.