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A Stratified Linear Sound Speed Profile Simplification Method for Localization Correction

Localization is important for underwater sensor networks as the validity of data and the maintenance of nodes both need location information. Because of the Snell effect caused by non-uniform distribution of sound speed, the signal propagation path is curved, which would lead to errors when traditional linear propagation localization models are used. Sound speed profiles (SSPs) can be used to correct the signal trajectory error according to the ray theory, so as to improve the localization accuracy. To simplify the expression of original SSPs and reduce the computational complexity of ray tracing while guaranteeing the accuracy, we propose a stratified linear SSP simplification method with a distance-minimization-based equal-interval control points searching (DM-EICPS) algorithm. Simulation results show that, compared with other curve approximation algorithms, the DM-EICPS algorithm not only generates simplified SSPs rapidly, but also achieves good SSP approximation accuracy. Moreover, the corrected localization accuracy with simplified SSPs is an order of magnitude higher than the linear propagation model, and the time overhead of ray tracing with simplified SSPs is obviously reduced compared to original SSPs.