Effect of acoustic horizontal refraction on DOA estimation with a single vector hydrophone

Abstract

The effect of horizontal refraction (HR) on DOA estimation with a single vector hydrophone is studied. It has been demonstrated in a previous study that HR may bring about a significant deviation between the true bearing of the source and the direction of time-averaged sound flux at the receiver point, i.e., DOA estimation error. [J. Tang et al., 2018, 43(2), ACTA ACUSTICA (in Chinese)]. In the present work, the DOA estimation error in a more realistic scenario is studied, more precisely, source signals are considered to be wide-band instead of time-harmonic, and meanwhile ambient noise is added to the received signal. The ocean waveguide used in simulations is a 3D version of the standard ASA wedge, which implies that the HR considered in this work is raised from multiple reflections between a horizontal sea surface and a sloping sea bottom. The results of this work shall offer some reference to DOA estimation in circumstances with strong HR effects.