In November 2021, the two submarine fiber optic cables of the Ocean Observatories Initiative (OOI) Regional Cabled Array (RCA) on the central Oregon continental margin were used to collect a 4-day public distributed acoustic sensing (DAS) dataset. The geometry of the cables and the 200-Hz sampling rate make the dataset ideal for fin whale passive acoustic monitoring. Tens of thousands of calls were recorded during the experiment, using a 30- to 50-m gauge length on nearshore spans of 65 and 95 km. We perform automated call detection by matched filtering and noise envelope subtraction to obtain arrival times from enhanced signal envelopes. We use a coarse grid-search algorithm to associate arrival times between the two cables and multiple calling whales. To localize, we use a weighted least-squares inversion with a constant sound speed and estimate two-dimensional call positions. This study will present the results of applying the automated method to the full dataset. The localizations and tracks will be used to understand the distribution of fin whales and their movement during the short experiment. We will also discuss the potential for using the OOI RCA for continuous monitoring of fin whales. Work supported by ONR.
Goestchel et al. (Wed,) studied this question.