NorthStar 951X Operator's Manual page 163

Choosing magnetic
variation
951/952 Operator's Manual Rev. B
If your unit is equipped with an internal differential receiver, differential
GPS corrections (DGPS—if available) will always be used when either
GPS or Phantom Loran is selected as the navigation source.
Use the NAVIGATION SOURCE option to select which source
to use. To change the option, press the (',7 menu key, and
use the &85625 3$' to view the choices. Press the (17(5
key to make your selection, or &/($5 to leave the option
unchanged.
Compasses naturally point to the magnetic north pole, which is
several hundred miles from the Earth's geographic north pole.
The difference between the angles to the two poles is known
as magnetic variation. The unit offers you the option of choos-
ing from:
•
True (0º)
•
Automatic (the unit calculates variation automatically,
according to your location)
•
Manual (from 0º to 180º, East or West)
The factory default setting is "automatic," to coincide with
your compass. Your navigation charts indicate the approxi-
mate magnetic variation for each area.
Under most conditions, you'll want the unit to calculate the
variation automatically for your position. Usually, the automat-
ically-calculated variation is entirely adequate for use.
True bearings are usually required when using a gyrocompass.
The manual setting (1º to 180º) is available for those times
when the display must match an older or less accurate chart,
or in remote areas (such as above 70º north latitude) where
the unit's variation calculations can be off by a significant
amount.
To change this option, press the (',7 key, then use the &85
625 3$' to view the choices. If choosing MANUAL, move the
cursor to the right to enter the variations for your area. Press
the (17(5 key to make your selection, or &/($5 to leave the
option unchanged.
Chapter 11 - Customizing the Unit
NOTE:
Page 153