Precision-improved Passive Localization Method in the Underwater Multipath Environment

Abstract

As a fundamental technology, localization plays a crucial role in the underwater wireless systems, which have been widely used in target tracking, disaster prevention and military domain. Due to the complicated environment in underwater, achieving the precise localization is still a challenge. In this paper, we propose a precision-improved passive localization method in the underwater multipath environment, where only anchors are clock synchronized and the effect of practical sound speed profile (SSP) is considered. In the proposed method, the underwater node to be localized employs the characteristic of direct paths and surface-reflected paths from anchors to realize the localization while the surface-reflected paths from some anchors are always undetectable. Simulation results show that the proposed localization method outperforms the localization schemes based on time difference of arrival (TDoA) and time of arrival (ToA) without ray-compensation. The performance of the proposed localization method is close to that of the localization schemes based on time of ToA with ray-compensation while ToA-based localization methods need strict clock synchronization between the underwater node and anchors.