Fin and humpback whale vocalization classification and localization, northern Georges Bank

Abstract

Several tens of thousand vocalizations from multiple fin whale individuals were passively recorded by a high-resolution coherent hydrophone array system in the Gulf of Maine in Fall 2006. The recorded fin vocalizations have short durations roughly 0.4 s and frequencies ranging from 15 to 40 Hz. The fin vocalizations were detected via spectrogram intensity thresholding. The horizontal azimuth or bearing of each detected fin whale vocalization was determined by broadband beamforming. Each vocalization was then characterized using numerous features, such as center frequency, upper and lower frequency limits, and duration, obtained from pitch tracking. These vocalizations were then classified using Bayesian-based Gaussian Mixture model feature clustering into several distinct vocal types. The vocalization clustering result was then combined with the bearing-time trajectory and localized by the moving array triangulation and the array invariant techniques. The vocalization types are found be dependent on the g...