Broadband Acoustic Communication Aided Underwater Inertial Navigation System

We present an underwater localization system for medium-sized Autonomous Underwater Vehicles (AUVs) that leverages a broadband wireless acoustic communication system for GPS-denied underwater localization. Many current acoustic localization systems assume a single line-of-sight path and use either narrow-band signals or short-duration pings for the convenience of mitigating motion-induced Doppler at the expense of the time-of-arrival (TOA) accuracy and operational flexibility. We propose a novel acoustic localization system that utilizes the aggressive signal processing embedded in underwater acoustic communication systems to resolve multi-path and Doppler distortion and finely estimate timing information using broadband communication signals. Timing and Doppler information extracted from this process is then used to estimate biases and drift from an inertial navigation system (INS) using a Bayesian framework. To demonstrate the feasibility of the system model, co-simulations are created from the MACE10 experimental data. Our results show dramatic improvement in localization accuracy, with an error of less than 120 m achieved over the 3$\sim$7 km distance range from the MACE 10 experiment between an AUV and a remote beacon with an acoustic communication transmission interval of 30 seconds.