Principles of surveying:
To locate the point with respect to two known points
Working from the whole to the part but not from part to the whole.
Accumulation of errors can be reduced.
Basic measurements in surveying:
Horizontal distance: Done by chain, tape, tacheometer, total stations.
Vertical distance: Level, total station, tachometer, sextant, Abbey level.
Horizontal angle: Compass, theodolite, clinometer, total station.
Vertical angle: Theodolite, sextant and total stations.
Principle of compass surveying: Direction of a line can be measured.
Types of meridian:
- True meridian: It is at a point a grade circle passing through the geographical north and south pole of earth’s surface.
- Magnetic meridian: It is a direction shown by a magnetic north when it is freely suspended.
- Grid meridian: It is a reference line established by state governments in the middle of the state for their projects in various departments.
- Arbitrary meridian: It is a local reference point taken for measurements.