R2Sonic 2022, Operation Manual

Page: 79 / 133

Page 79 of 133
Version 3.0 REV r000
Date 25-08-2010
The example, below, will illustrate the math involved.
Figure 72: Gyro Calibration Method 2 example
A to A' 1.0 metres B to B' 1.5 metres
Side a 5.0 metres Side b 1.5 – 1.0 = 0.5 metres
Angle b'
Arctan 0.5/5.0 = 5.7
°
Ship Azimuth = 270
°
+ 5.7
°
= 275.7
°
Table 9: Gyro Calibration Method 2 computation
Figure 73: Idealised concept of Gyro Calibration Method 2
In this example, the vessel heading for this set of readings is 275.7
°
; this would be compared to the
gyro reading recorded at the same time the offsets were measured.
In the above example, if the bow was further out from the quay than the stern, the angle b' would
be subtracted from the azimuth of the quay, i.e. 270
°
- 5.7
°
= 264.3
°
.