Single hydrophone passive acoustic ranging in deep water

Single hydrophone passive acoustic ranging is the practice of estimating the range to an underwater sound source using acoustic recordings from a single receiver. We present a multi-path arrival-based approach to estimate the horizontal range between a submerged source:receiver pair in a deep ocean environment (in which multi-path arrivals can be resolved and modal dispersion is minimal). A cost function and optimization approach are presented that are automated and robust to some significant sources of noise (including multiple sources) and environmental uncertainty. While several multi-path ranging methods have been presented in past literature, an important contribution of our approach is that it can be fully automated, it relaxes the requirement that arrivals are labeled/identified a priori, and it can function in multiple-source scenarios. Underwater acoustic data recorded by the ALOHA Cabled Observatory (ACO) are processed using our single hydrophone ranging approach. The horizontal range to 296 airgun shots, recorded by ACO on October 5-6, 2018, is compared against the true range for each shot. Good agreement between the true and estimated ranges demonstrates the performance of the ranging approach.