A real-time direction finding device for determining the bearing to the underwater sounds of Southern Right Whales, E u b a l a e n a a u s t r a l i s

The correlation of sounds with behavior in groups of free-ranging whales has been restricted by the difficulty of determining which animal made the sound. A real-time device was designed and built to directionalize on the underwater sounds of Southern Right Whales, Eubalaena australis. The device measures the phase difference between the signals from a two-dimensional hydrophone array and calculates a bearing to the sound source. Results of field calibration tests demonstrated that the system could reliably directionalize on right whale sounds with a resolution of ±12° except for arrival bearings within 25° of the array’s axis.