
Sponsored by the Office of Naval Research
An acoustic communications system with the
capability to operate at multiple data rates in two
frequency bands has been designed and developed for use
in 21-inch AUVs. The system is specifically designed
around the 21-inch diameter Bluefin Robotics AUV,
though it could be adapted to smaller vehicles (12-inch),
or similar free-flooded vehicles. The system includes both
high (25 kHz) and mid-frequency (3 kHz) modems and
supports data rates from 80 bps to more than 5000 bps.
Both of the modems utilize four-channel arrays to
increase reliability. The high-frequency modem is also
used to support multi-vehicle navigation via one-way
travel time measurements using synchronized clocks on
all of the vehicles in a work group.