APS/C&M has developed a number of oceanographic data collection systems and special purpose underwater devices for government laboratories, industry and universities. We have designed, manufactured, tested and managed the at-sea deployment and retrieval of instrumentation systems to ocean depths of 20,000 feet. Our personnel have designed acoustic data collection systems employing vertical and horizontal hydrophone arrays, data acquisition units (DAUs), surface buoys and RF Telemetry.
DATA TELEMETRY SYSTEMS
APS/C&M 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.
GEOPHONE ARRAY SYSTEMS
The Naval Oceanographic and Atmospheric Research Laboratory (NOARL) contracted APS/C&M to design and fabricate two seafloor geophone arrays for the measurement of the seismo-acoustic wavefield in deep water. These arrays were to interface with NOARL-supplied bottom recording systems. Specific characteristics of the array system are described below:
|Leveling: Self-leveling 2 axis gimbal
Depth rating: 6000 Meters
Array: 12 sensor modes
Node spacing: 2 to 32 meters
Sensor: 3-axis geophone
Experiment: 30-day deployment
Geophone Node Testing
Motorized Gimbal System