Calibration Level 9: Magnetic Variation; Calibration Level 10: Heading Error Correction - Raymarine ST3000 Owner's Handbook Manual

Chapter 6: Adjusting Wheel Pilot Settings

Calibration Level 9: Magnetic variation

Use Calibration Level 9 to input the level of magnetic variation
present at the boat's current position.
•
•
The wheel pilot transmits this value onto the SeaTalk bus, so it can be
picked up by other SeaTalk instruments.

Calibration Level 10: Heading error correction

Use Calibration Level 10 to switch on Northerly or Southerly heading
error correction:
•
•
You might notice that the autopilot tends to be a little less stable on
Northerly headings in the higher latitudes of the Northern hemisphere
(or Southerly headings in the Southern hemisphere).
This is caused by the increasing angle of dip of the earth's magnetic
field at higher latitudes, which has the effect of amplifying rudder
response on Northerly (Southerly) headings. This error affects all
magnetic compasses and gets worse further away from the equator.
With heading error correction switched on, the wheel pilot can
compensate for this error by automatically adjusting the autopilot
gain (depending on heading). This will provide precise course
keeping on all headings.
-ve variation = west
+ve variation = east
0 = Off
1 = Northern Hemisphere, 2 = Southern Hemisphere
with
compensation
without
compensation
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