User Manual for the Type 8300 Compatt 6
(and Variants)
UM-8300-Compatt 6
Issue B3
Similarly, if Compatt beacons are used for the seabed array, the L/USBL system can command them
to self-calibrate. Using Compatt beacons has the additional advantage of giving the system
significantly more flexibility, in that they can be commanded to respond on any of a variety of
frequencies and with any desired turn-around delay time. This means that a Compatt version of the
system becomes simpler and faster to set up and use.
A.4.5 Dual Operation
Two complete sets of L/USBL equipment can be operated in tandem to provide dual redundancy.
When used in this way, the two systems are linked in such a way that, following failure of any major
element, the system can continue to operate without the need for operator intervention. Operation of a
dual-redundant system is identical to that of a standard version.
In dual redundancy, one system operates as the ‘master’ and the other operates as the ‘slave’. The
slave system monitors the functions and performance of the master and takes over system operations
if it detects any failure.
A.5 Long-short USBL (LSUSBL)
A.5.1 Hardware
In a LSUSBL system, four or more transceivers are deployed below the vessel, and four or more
beacons are deployed on the seabed.
A.5.2 Principles
LSUSBL mode is a combination of USBL, LBL and SBL modes. The reference array is interrogated
from one transceiver, and the replies from all the beacons are collected at all the transceivers. All the
resulting measurements are used to derive a single solution of the vessel’s position.
This single solution comprises SBL, USBL and LBL components:
Ranges to each beacon are collected at all the transceivers, giving an SBL component to the solution.
The LBL component arises from the ranges three or more beacons having been collected.
The USBL component arises from both range and direction calculations derived from the multiple
transducers of a single transceiver.
LSUSBL uses the same equipment and configuration as LUSBL but uses data from more
transceivers. It is not specifically described in this manual. If operating in LSUSBL mode, use the
description for L/USBL but enter the additional transceivers.
Appendix A – Acoustic Positioning Methods
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