PASSIVE ACOUSTIC LOCALIZATION AND TRACKING OF NORTH ATLANTIC RIGHT WHALES WITH A COMPACT HYDROPHONE ARRAY ON AN UNDERWATER GLIDER

Abstract

North Atlantic right whales (NARW) are critically endangered (~380 remaining). Passive acoustic monitoring is used for detection and classification of the NARW vocalizations, but localization and tracking are limited. This thesis investigates the capabilities of localizing and tracking a NARW using an underwater glider equipped with a compact volumetric array (CVA). Multiple azimuth estimators and sound pressure level (SPL) ranging are tested in simulation and an in-water experiment. The novel azigram-KDE implementation yielded the most accurate and robust azimuth estimates, while SPL-ranging resulted in high estimation error due to source level and propagation loss uncertainty. A tracking framework was implemented, reducing in-water experiment Euclidean distance mean absolute error by 69%. The tracking framework was tested further in simulation using realistic NARW vocalization and motion behaviour, and improved localization accuracy for all cases. This thesis presents the viability and limitations of a single glider-CVA for marine mammal localization and tracking.