RSS-based sensor localization in underwater acoustic sensor networks

Abstract

Since the global positioning system (GPS) is not applicable underwater, source localization using wireless sensor networks (WSNs) is gaining popularity in oceanographic applications. Unlike terrestrial WSNs (TWSNs) which uses electromagnetic signaling, underwater WSNs (UWSNs) require underwater acoustic (UWA) signaling. Received signal strength (RSS)-based source localization is considered in this paper due to its practical simplicity and the constraint of low-cost sensor devices, but this area received little attention so far because of the complicated UWA transmission loss (TL) phenomena. In this paper, we address this issue and propose two novel semidefinite programming (SDP) approaches which can be solved more efficiently. The numerical results validate our proposed SDP solvers in underwater environments, and indicate that the placement of the anchor nodes influences the RSS-based localization accuracy similarly as in the terrestrial counterpart. We also highlight that adopting traditional terrestrial RSS-based localization methods will fail in underwater scenarios.

Target Localization in Underwater Acoustic Sensor Networks Using RSS Measurements

“…Without loss of generality, we assume that noise n i is sufficiently small, and let d 0 = 1 m [12,15]. From Equation (1), we have the following approximation expression…”

“…It was shown in [12,18] that, when the absorption coefficient α f is sufficiently small, the absorption term α f x − s i can be relatively small (α f x − s i 10γ ln 10 ), especially in deep water; then, 0 < |u| 1.…”

“…. , N, the RSS of the UWA propagation between the i-th anchor node and the target node is measured in dBm and has the log-normal shadowing model as follows [12]:…”

“…Additionally, as AoA relies on a direct line-of-sight path from the target node to anchor nodes, it will cause large errors in AoA measurements in multi-path underwater acoustic (UWA) transmission environments [7,8]. Therefore, RSS-based target localization is preferred by researchers due to its low complexity and easy implementation [9][10][11][12]. Based on the received signal strength measurements, the maximum likelihood (ML) method is used to estimate the target position [13], and this method is robust in underwater environments.…”

“…In [11], the authors discuss the convex optimization method for target localization in UWSN, while the propagation model is still the terrestrial acoustic wave model. Two convex methods based respectively on RSS-based and frequency-dependent differential approaches in UWSN have been proposed [12]. A hybrid localization method was investigated by combining ToA and RSS measurements [10].…”