7986 Datasheet, PDF (1/2 Pages) Sonardyne sound in depth – Lightweight Release Transponder (LRT)

Sonardyne UK (Head Office)
T. [phone]
F. [phone]
E. [e-mail]
www.sonardyne.com
Datasheet
Lightweight Release Transponder (LRT)
Description
Part of Sonardyne’s Coastal
Acoustics product range, the Type
7986 Lightweight Release
Transponder (LRT) has been
developed from transponders used to
accurately position hundreds of
seismic receiver nodes. It has both
receive and transmit functions, unlike
similar low-cost release transponders,
enabling accurate slant ranges to be
measured, release actuation to be
confirmed and its position to be
determined.
The LRT is depth rated to 500 metres
making it the ideal choice for use in
continental shelf waters. Field
replaceable alkaline or lithium
battery packs give a listening life of
18 months and 52 months
respectively. A ‘screw-off’ release
mechanism ensures a positive release
action that overcomes any biological
growth and all external parts are
made of high strength plastics that
provide excellent corrosion
resistance.
The Type 7967 surface control unit
comprises a low-cost deck unit and
remote transducer on 10 metres of
cable. The deck unit is initially used
to program the acoustic identity of
the LRT, test the transponder and
load the release ‘bit’ prior to
deployment. Once deployed, the
deck unit can measure ranges to the
transponder and prior to sending a
secure release command, relocate
the transponder. The deck unit can
be controlled via RS232 enabling
raw range data to be logged to a
PC.
Key features
• Safe Working Load of 125Kg
• Depth rated to 500 Metres
• Over 4 years deployment with
long-life Lithium battery pack
• Thousands of secure identities; field
programmable with deck unit
• Reliable, 'screw-off' release
• Rugged, compact design
• Compatible with Scout USBL, ROV-
Homer, Homer-Pro and Prospector
positioning/relocation systems
• Optional rope canister with 75
Metres of 1200Kg breaking-strain
rope
The transponder is compatible with
Sonardyne’s ROV-Homer and Homer-
Pro target relocation systems.
Deployed at a point of interest and
weeks or years later, the LRT can be
interrogated to provide range and
direction guidance to a ROV pilot or
diver wishing to home back on to it.
Furthermore, the transponder’s exact
seabed co-ordinates can be quickly
and easily determined using
Sonardyne’s Prospector system,
calibrated from a dGPS positioned
vessel. A rope canister is also
available with 75 metres of rope for
pop-up buoy applications.