Declination and Local Attraction
Why this Video is Important?
Concept of Declination and local Attraction is very important because it affects the True Bearing and Magnetic Bearing of any line. In this video we are able to calculate all these parameters without using any formula and we can easily visualize and analyze these errors .
Real Life Applications:
The bearings are used to calculate the location of different points and lines on the earth .After calculating the location, we can further calculate the length, Area or Volume and proceed further in our Surveying.
The True bearing is calculated from the true north to the line in clockwise direction .The Magnetic bearing is calculated from the magnetic north to the line in clockwise direction .The angle between True north and Magnetic north is Declination. If magnetic north is in right side of the true north, the declination is +ve or eastward. If magnetic north is in left side of the true north, the declination is –ve or westward. Similarly the angle between the actual magnetic north and new magnetic north is the Local Attraction. The angle measured from new magnetic north is observed/measured magnetic bearing and the angle measured from actual magnetic north is actual/true magnetic bearing. The Declination is due the earth’s own magnetic field and The Local Attraction is due to external magnetic field.