| A long-baseline acoustic system has been developed for the tracking of humpback whales (Megaptera novaeangliae) that have been tagged with digital acoustic recording devices, or DTAGs, providing quantitative observations of submerged whale behavior. The system includes three acoustic sources deployed from small-boats that follow the whale after the animal has been tagged. Integrated GPS provides positioning and synchronized operation of the sources. Time-encoded signals from the sources are recorded along with whale vocalizations and ambient noise on the whale tag. Time-of-flight measurements, as measured by the tag acoustic data, are converted to range from the whale to each source with a nominal sound speed. A non-linear least-squares solution is then solved for the whale's position. The system is demonstrated with data collected from a tagged animal in the summer of 2007. |
