Data Acquisition & Telemetry Systems
Data Telemetry Systems

C&M Technology designed, built and tested a custom, high frequency data collection system to support acoustic research in shallow waters. Three acoustic nodes were deployed several thousand feet apart in a shallow bay. Each node contained a 3-channel, 22kHz acoustic array, sound source and power amplifier. The nodes were cabled to a central Data Acquisition Unit (DAU), which digitized the node data and transmitted it to a Surface Telemetry Buoy (STB). The STB radioed the data (10Mb/sec.) in real time to a nearby site for display, processing and recording.

The in-water system was remotely-controlled by radio from the receive site. Commands were used to turn the system on and off, set gains, actuate self-test modes and control the sound sources. The sound sources could be commanded to output one of several different waveforms (stored in DAU memory), at a selected amplitude. Because the outgoing waveforms were synchronized precisely to the DAU data frame, accurate time-of-flight measurements could be made.

The DAU could also interface to 32 low-bandwidth, non-acoustic type sensors (pressure, temperature, environmental, etc.) using a general-purpose sensor port on the DAU housing. The non-acoustic signals were digitized and merged with the 10Mbit node telemetry.

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