David S. Clark
NRaD, San Diego, CA 92152-5000
ORINCON Corp., San Diego, CA 92121
The marine mammal acoustic tracking system (MMATS) provides real-time display and signal processing of ten channels of acoustic data. In this study analog signal data from ten sonobuoys were radioed to a circling aircraft carrying the MMATS hardware; the data were transformed into an intensity/time/frequency display scrolling in real time. Whale species were determined from the signal characteristics; the system includes a neural network for automated detection. Arrival time delays of a signal at three or more sites were used to localize the whale. Acoustic identification and localization of the whales were visually confirmed by observers making an independent visual survey of the area at the same time. Acoustic monitoring capabilities of the type provided by MMATS can significantly reduce the number of whales missed by traditional visual-only monitoring and provides a means of calibrating both methods, reducing the statistical uncertainty of population estimates made using either technique alone. Because MMATS can monitor large areas for long periods of time, it is well suited to monitoring the effects of manmade noise on the activities of whales.