Telemetry receiver and acoustic command system

A shipboard Telemetry Receiver Acoustic Command System (TRACS) was designed to be used for two way acoustic communication with and relocation of underwater instruments. The design objectives were compact size, low cost, multi-purpose capabilities, and ease of operation and maintenance of the system. The telemetry receiver system utilizes a four-hydrophone array, bandpass filters and amplifiers, precision time-base for synchronization, a writing amplifier, and a helix, wet-paper recorder. The Acoustic Command System (ACS) incorporates an adjustable digital acoustic command generator, a power amplifier, an underwater sound transducer and an adjustable ACS test output circuit useful for alignment of underwater acoustic receivers. Two systems have been used successfully at sea on four cruises.