Localization and tracking of underwater physical systems

In this paper, we investigate the problem of localizing an underwater sensor node based on message broadcasting from multiple surface nodes. With the time-of-arrival measurements from a DSP-based multicarrier modem, each sensor node localizes itself based on the travel time differences among multiple senders to the receiver. Using one-way message passing, such a solution can scale to accommodate a large number of nodes in a network. Continuing on our preliminary work in [1], we in this paper focus on the tracking solutions at the node processing layer. We present simulation results as well as testing results in a swimming pool with both stationary and moving receivers.