Underwater Acoustic Network as a Deployable Positioning System

Abstract

Underwater acoustic communications networks serve to pass data between submerged nodes and a command and control center ashore. Range data recorded incident to regular transmissions between nodes afford the acoustic network an additional use as a navigational aide or tracking system for a vehicle operating in the network domain. Previous studies developed algorithms to solve for the position of the mobile node using node-to-node range data. An alternative localization algorithm is proposed. This study implements the algorithms for experimentation in simulation and an actual maritime environment. Reference nodes are deployed to establish a Seaweb network in Del Monte Lake on the Naval Postgraduate School campus. Experimental range data are recorded and used to plot the path of a surface vehicle towing a network sensor node. GPS fixes are simultaneously recorded for comparison of the calculated track to the true track. This comparison throughout the experiment provides a more definitive measure of the localization algorithms performance than was possible in previous studies.