Marine Mammal Monitoring on Navy Ranges (M3R): A Toolset for Automated Detection, Localization, and Monitoring of Marine Mammals in Open Ocean Environments

Abstract

AbstractNavy sonar has been associated with a number of marine mammal stranding events worldwide. As a result, determining the effects of anthropogenic noise on marine mammals is currently an active area of research. The development of methods to detect and localize the animals in their native environments is key to advancing this research and our understanding. This paper presents a collection of algorithms for automated passive acoustic detection, classification, and localization of vocalizing marine mammals in open ocean environments. The tool set known as M3R (Marine Mammal Monitoring on Navy Ranges) uses the large fields of wide-bandwidth bottom-mounted hydrophones that are part of the U.S. Navy’s undersea ranges to listen for vocalizing whales. M3R employs time-frequency analysis to passively detect whale vocalizations; it then aligns detections among neighboring hydrophones to determine the difference in times of arrival (TDOA) of each vocalization. Sets of TDOA are then used to determine 2-D or 3-D position points using hyperbolic localization techniques. An M3R system is capable of continuous, automated, real-time monitoring of over 200 wide-bandwidth hydrophones covering 2,000+ km2of open ocean. M3R is typically used in a collaborative fashion to localize animals in support of tagging exercises, visual surveys, and behavioral response experiments.