R2Sonic 2026 - 10.3 Measuring Offsets; 10.3.1 Sonic MBES Acoustic Centre; 10.3.2 Horizontal Measurement

Page 160 of 254
Version
6.3
Rev
r012
Date
05-11-2022
Part No. 96000001
10.3 Measuring Offsets
The accurate measurement of offsets is vital to the accuracy of the survey data. If possible, the
vessel will be put on a hard stand so that it can be very accurately measured using standard land
survey equipment, such as a total station. However, this may not be possible, and the offsets will
have to be measured using tape and plumb-bob, which is detailed below.
10.3.1 Sonic MBES Acoustic Centre
Please refer to the drawings appendix to obtain measurements, with reference to the system
offsets, when mounting on the Sonic mounting frame.
Figure 176: Sonic 2026/2024/2022 Acoustic Centre
10.3.2 Horizontal Measurement
All measurements should be made with a metal tape measure. A cloth tape can stretch, it can also
be knotted or kinked, unknown to the persons making the measurements. At a minimum, two
people should be assigned to take the measurements; three people will work better with the third
person writing down the measurements. One person will be the holder, and the other will be the
reader. Starting at either the reference point or the sensor, the distance will be measured. When
Alongship ref
Athwartship
ref
Z
Reference
FOREAFT
SONIC 2024 Side View
SONIC 2024 Plan View
120mm
39mm
187mm
240mm
Connector under
35mm
standoffs
Acoustic Centre
Alongship ref
Athwartship
ref
Z
Reference
FOREAFT
SONIC 2022 Side View
SONIC 2022 Plan View
120mm
39mm
187mm
138mm
Connector under
35mm
standoffs
Acoustic Centre
Alongship ref
Athwartship
ref
Z
Reference
FOREAFT
SONIC 2026 Side View
SONIC 2026 Plan View
187mm
240mm
Connector under
240mm
Acoustic Centre