Underwater navigation using a single beacon based on the time delays of the direct signals and the surface-reflected signals

Abstract

Underwater navigation using a single beacon has been widely discussed and used because of the lower hardware complexity and installation accuracy compared with the long baseline (LBL) and the ultra-short baseline (USBL) methods, respectively. The existing navigation methods are mainly dependent on the time delays of the direct signals (DS) from the beacon to the autonomous underwater vehicle (AUV). Considering that the underwater acoustic channel is a multipath channel, this paper proposes a novel single beacon navigation method based on the time delays of the direct signals and the surface-reflected signals (SRS). The precision analysis proves that the proposed DS-SRS-based method can achieve a higher navigation precision than the DS-based method. Moreover, a tracking method based on the DS and the SRS is also presented to smooth the navigation results, and the corresponding observability analysis is given. Several simulations validate the effectiveness of the proposed methods.