R2Sonic 2022, Operation Manual

Page: 78 / 133

Page 78 of 133
Version 3.0 Rev r000
Date 25-08-2010
Part No. 96000001
8.2.1.2 Tape and Offset Method of Gyro Calibration
This method relies on measuring the offset distance from a baseline on the quay, with a known
azimuth, to a baseline that is established on the vessel. There are greater areas for error when using
this method, particularly in establishing a baseline with known azimuth.
A baseline is established on the quay as close as possible to the vessel's side. It is very important
that the azimuth of this baseline be as accurately determined as possible. The baseline should be of
a length that will exceed the baseline that is established on the vessel.
A baseline is established on the vessel that is parallel to the centre line of the vessel. It should not
be assumed that the side of the vessel is parallel to the centre line. This baseline should be on the
deck that faces the dock. The baseline on the vessel should be as long as possible, the longer the
better.
With the vessel secured alongside the quay, the vessel baseline will be compared to the quayside
baseline. Two points will be established on the quayside baseline that corresponds exactly to the
fore and aft positions on the vessel baseline. That is: the points that are established on the quayside
baseline should be normal to the points on the vessel baseline.
Figure 71: Gyro Calibration Method 2