A ROBOTIC BOAT FOR AUTONOMOUS FISH TRACKING

We have developed a small robotic system that we hope can reduce the c ost of gathering data on the movements of large fish and marine mammal s. This tracking system is contained in a 10', low-cost kayak hull and includes subsystems that allow for its autonomous operation while fol lowing a tagged, swimming animal. The hull is polyethylene and houses lead-acid batteries for power, electric propulsion through a large, ef ficient propeller, a keel for stability and course-keeping, and a rudd er servo for steering. An acoustic transducer is the prime mission sen sor while we have installed a compass and GPS receiver for navigation. Three computers control the system, one for overall mission control, another for propulsion motor control, and another for sensor orientati on. This paper describes in detail the prototype system as configured with a Vemco V60 receiver with a V11 (28-32 kHz.) hydrophone mounted o n a scanning mechanism. We describe the operation of this system and d iscuss other sensor options and their implications on system performan ce. We describe the behavior algorithms implemented in the mission con trol software and the user interface facilitated by a removable RS-232 link to a laptop computer. Finally, we present the implications of th is system on the economics of deep-ocean tracking studies.