Clawgear Mission Sensor - 12.5 Compass Mode - Magnetic Declination Compensation

12.5 Compass Mode - Magnetic Declination Compensation
0°
0°
magnetic
north
magnetic
north
ture north
ture north
point A
object B
object B
point A
ture
bearing
300
°
ture
bearing
300
°
magnetic
declination
23
°W
magnetic
declination
22
°E
True Bearing (TB) =
Magnetic Bearing (MB) + Easterly Magnetic Declination (E)
300° (TB) = 278° (MB) + 22° (E)
True Bearing (TB) =
Magnetic Bearing (MB) + Westerly Magnetic Declination (W)
300° (TB) = 323° (MB) + 23° (E)
magnetic
bearing
323
°
magnetic
bearing
278
°
Compensate the Bearing
with Easterly (E) Magnetic Declination
Compensate the Bearing
with Westerly (W) Magnetic Declination
Magnetic Declination Compensation
• To compensate for an object's bearing, either subtract
westerly (W) magnetic declination or add easterly(E)
magnetic declination with the magnetic bearing.
• Example 1: Westerly magnetic declination 23°and the
compass needle points 323°.
- TB = MB - W. When MB = 323°; W =23°
- TB = 323° - 23°
- TB = 300°
- The true bearing is 300°
• Example 2: Easterly magnetic declination 22° and the
compass needle points 278°.
- TB = MB + E. When MB = 278°; E = 22°
- TB = 278°+ 22°
- TB = 300°
- The true bearing is 300°
• The Watch allows you to compensate the compass
bearing at a place where the magnetic declination is
either Westerly declination or Easterly declination.
• Check the coming section "Calibrating the Compass" for
more details of the setting.