The main difference between a true bearing and a compass bearing lies in their reference points.
- True bearing is measured clockwise from true north, which is based on the Earth's geographical North Pole.
- Compass bearing is measured clockwise from magnetic north, which is the direction a compass needle points due to the Earth's magnetic field.
Here's a breakdown:
True Bearing:
- Reference Point: True North
- Measurement: Clockwise from True North
- Used for: Navigation, mapping, and accurate location identification.
Compass Bearing:
- Reference Point: Magnetic North
- Measurement: Clockwise from Magnetic North
- Used for: Basic navigation, especially with compasses.
Practical Insight:
The difference between true north and magnetic north is called magnetic declination. This variation changes geographically and over time. Therefore, compass bearings need to be adjusted for magnetic declination to obtain accurate true bearings.
Example:
Let's say a true bearing is 045° (45 degrees clockwise from true north). If the magnetic declination at your location is 10° east, then the compass bearing would be 035° (45° - 10°).
In summary:
- True bearing is based on the Earth's geographical North Pole.
- Compass bearing is based on the Earth's magnetic North Pole.
- Magnetic declination is the difference between true north and magnetic north.
