Model-based tracking of marine mammals

Abstract

Data from the August 2003 experiment conducted by the Scripps Institution of Oceanography in the Southern California Offshore Range (SCORE) are used to track marine mammals. SCORE is a naval training area near the island of San Clemente located in relatively shallow water. The water depth where the experiment was conducted is around 360 meters. Data were recorded on a 100-m, eight-element vertical line array (VLA) deployed from the floating instrument platform (FLIP) and four bottom-mounted hydrophones deployed in an area covering approximately 3 square kilometers. During the course of the 7-day experiment continuous recording of the ocean environment was made. The recordings contain calls from various marine mammals, particularly blue and fin whales. Data recorded on the bottom-mounted hydrophones and the VLA are used to track singing marine mammals using two entirely different model-based tracking techniques: The animals are tracked by comparing the predicted (using a propagation model) and measured time difference of arrival recorded in pairs of bottom-mounted hydrophones. Additionally, matched-field processing on the VLA data is used to estimate the range and depth of the animals.