Specifications

GLOSSARY OF TERMS
vi
hydrophone at the same time.
Slant Range
The range from a target to the listening hydrophone. (Computed by the
travel time from target to hydrophone multiplied by the speed of sound in
water.)
Telemetering
Beacon
Can either be a transponder or a responder. It outputs two replies in re-
sponse to an interrogation. The first reply is the navigation pulse for the
BATS and the second reply is the telemetry pulse. The time delay between
the two replies is proportional to the sensor output on the telemetry beacon.
Trackman
EdgeTech’s Windows® based USBL Interface Software. Communicates with
the BATS Transceiver to allow modification of the target & system parame-
ters and also outputting of processed data to Navigation packages.
TrackPoint 3
EdgeTech’s Model 4450A USBL Tracking System. A high accuracy survey
quality acoustic navigation system.
Transponder
An underwater sound source which responds to an underwater signal (de-
vice is interrogated acoustically) and returns with an underwater acoustic
reply. Sometimes abbreviated as "XPDR".
Turn Around
Time
A preset time delay, built into a transponder or responder, between when a
device is interrogated and when it replies. The delay is calibrated at the
xponder to compensate for variations in receiver propagation delays.
USBL
Ultra Short BaseLine - A type of acoustic navigation system which utilizes an
array of receiving elements spaced very close together (within inches). (As
opposed to Long Baseline Systems)
VRU
Vertical Reference Unit - Used to compensate for pitch and roll motion of the
ship.
X
The port (-) to starboard (+) direction which the target is referenced to
(e.g., bow of vessel or north).
Y
The aft (-) to bow (+) direction which the target is referenced to. (e.g., bow
of vessel or north)
Z
The targets depth. Referenced from the plane of the hydrophone elements
or offset point to the target.