Simulations of broadband multipath signals for vector hydrophone and the orientation performance study

A finite difference model for acoustic velocity signals based on ray theory is proposed when the emitted signal waveform is known.The computation time is reduced significantly in the case of broadband signals at the tolerance of accuracy.Simulations are conducted in shallow waters to analyze the arrival patterns of multipath signals at short and long ranges and its influence on the elevation estimation performance of the vector hydrophones is analyzed.The results show that the multipath coherent signals severely degrade the estimation performance of the vector hydrophones,and thus matched field processing or signal processing techniques to pick up the direct arrival signals should be used to improve the performance.Using the iso-speed profile as an approximation to the weak negative gradient sound speed pro-file(SSP) influence little on the waveforms of pressure and vertical velocity signals,but greatly on the waveform of horizontal velocity signals.