Operator Unit
130--613
Operator Unit
33
Edition: March 11, 2005
3648/130--613.DOC010102
Comments regarding Speed Error Correction
Speed error is a physical deviation from the steering heading indicated on the gyro
compass (compass heading) from the true heading (chart heading).
The speed error depends on the speed of the ship, the heading it is steering and the
latitude. A speed-error table takes these items into consideration.
The ship’s acceleration also affects the gyro system. Since this is a non linear error the
speed-error table cannot take it into consideration.
The correction values are calculated within the gyro system and added or subtracted to
the compass heading.
So, in the event that the speed error correction function is actiavted by manually entering
speed and latitude, dynamic speed error correction will also be carried out.
This can lead to unexpected results because acceleration
is produced by a simulated speed change (as opposed to
the ship’s speed) and this can lead to inaccurate correction
values.
The result of the correction will only be correct if the manual
entries (speed/latitude) align with the current ship’s
dynamics.