Optimal estimation of glider's underwater trajectory with depth-dependent correction using the Navy Coastal Ocean Model with application to antisubmarine warfare

Abstract

An underwater glider is a cost-effective underwater unmanned vehicle with high-endurance for oceanographic research or naval applications. Its navigation and localization accuracy are important because these accuracies provide spatiotemporally high resolution ocean data with saving energy and time. The glider, however, is affected by the ocean currents because of its minimal velocity, which is due to its buoyancy-driven propulsion system. It also lacks of inexpensive and efficient localization sensors during its subsurface mission. Therefore, knowing its precise underwater position is a challenging task. This study attempts to develop a novel correction method for estimating a glider’s optimal underwater trajectory. In four steps, it compares the corrected trajectories, which are developed using depth-averaged and depth-dependent correction methods using the Regional Navy Coastal Ocean Model (NCOM). The results suggest that the depth-dependent correction method is more accurate. This study for estimating a glider’s underwater trajectory accurately would be beneficial to oceanographic research and naval applications, especially antisubmarine warfare (ASW) such as operating Intelligence, Surveillance, and Reconnaissance (ISR); operating littoral ASW; providing communication networks; and supporting tactical oceanography.