A Multichannel Ultrasonic Marine Biotelemetry System for Monitoring Marine Animal Behavior at Sea

摘要

Up to eight multiplexed channels of shark behavioral data at sea are obtained with a 40-kHz acoustic transmitter with a range exceeding 5 km and a life of up to 1 week. Conservation of battery power is achieved with complementary metal-oxide semiconductor (C/MOS) integrated circuits (IC's) and a pulse-interval data format of 10-ms pulses at intervals between 200 ms and 2 sec. A multivibrator oscillator is used to control the operating frequency, which is essentially independent of temperature and pressure and decreases slightly with battery voltage (