Teledyne SeaBat T Series, Operator'S Manual, Page: 56 / 152

ACTIVE SONAR USAGE
SeaBat T-Series Subsea Operator's Manual Page 44 January 31, 2019
Version 7
When the vessel rolls the swath is rotated and the projected swath on the seafloor is laterally displaced.
Figure 16: Laterally Displaced Swaths under Roll Conditions
This has the effect of reducing the usable
swath width due to the distortions on the
edge.
With the input from a motion sensor (and roll
stabilization enabled) to steer each receive
beam dynamically for every sample, the swath
stays vertical irrespective of vessel motion
thereby maximizing swath.
Figure 17: Swath under Roll Stabilization
It is recommended that the motion sensor data update rate is at least 50Hz and preferably 100Hz.
Baud rate and protocol details can be set in Motion Stabilization, but it should be ensured that the
baud rate is sufficient to allow the desired update rate.
NOTE
A warning will appear in the SUI, if the motion sensor update rate is lower than 20Hz.
For instructions on motion sensor configuration, refer to the RESON Sonar UI User Manual ( see
Appendix E Reference Documentation ).
6.3.4 Head Tilt
In certain applications it is desirable to physically rotate the sonar head. Instances of this are
pipeline surveys where a dual head normally mounted on an ROV are inclined inwards to
maximize the number of hits on a pipe. Another application is survey of harbor walls or other
vertical structures where the desire is to survey as close to the waterline as possible.
NOTE
EA beams are recommended when using head tilt, as ED beams are still formed assuming a
horizontal seafloor.