A two-hydrophone range and bearing localization algorithm with performance analysis

Abstract

An automated, passive algorithm for detecting and localizing small boats using two hydrophones mounted on the seabed is outlined. This extends previous work by Gebbie et al. [(2013). J. Acoust. Soc. Am. 134, EL77 - EL83] in which a similar two-hydrophone approach is used to produce an ambiguity surface of likely target locations leveraging multipath analysis and knowledge of the local bathymetry. The work presented here improves upon the prior approach using particle filtering to automate detection and localization processing. A detailed analysis has also been conducted to determine the conditions and limits under which the improved approach can be expected to yield accurate range and unambiguous bearing information. Experimental results in 12 m of water allow for a comparison of different separation distances between hydrophones, and the Bayesian Cramér-Rao lower bound is used to extrapolate the performance expected in 120 m water. This work demonstrates the conditions under which a low cost, passive, sparse array of hydrophones can provide a meaningful small boat detection and localization capability.

Anchorless underwater acoustic localization

“…The wealth of multipath arrivals that results can be exploited in passive systems in order to improve the localization accuracy [8], or to localize the source with multiple receivers through an acoustic propagation model [9]. Model-based range-bearing localization with two anchor nodes was introduced and evaluated by [10]. Along the same line, some systems have been proposed that attempt to localize a node based on a collection of acoustic channel fingerprints measured in the localization area [1].…”

Underwater TDOA/FDOA joint localisation method based on cross‐ambiguity function

“…In underwater sensor networks, the acoustic waves are the primary means of carrying information, which can cover sea areas of several cubic kilometres [2]. Time difference of arrival (TDOA)‐based passive acoustic localisation proved to be a feasible method [3, 4]. Factors affecting the accuracy of underwater localisation include environmental noise, sensor position fluctuations [5] etc.…”

Error calculation in cross-correlation based population estimation technique of fish and mammals

“…Population size estimation of fish and mammals is a primarily important topic in conservation of ecology and management, which can say acoustically sensitive times and areas to be prioritized. Nowadays, passive acoustic monitoring is increasingly used to locate soniferous fish and mammals [1], which are problematic to monitor using conventional visual techniques. Unlike underwater diver surveys [2] or mark recapture techniques [3], it has the advantage of being a non-invasive and non-destructive monitoring tool.…”