Introduction to Surveying, Plane Surveying and Geodetic Surveys

Consider an area on the Earth's surface with undulations and water bodies. 

Surveying techniques measure the lengths and breadths of an area and identify the ground levels with reference to a datum.

These techniques measure the angles of corners, the inclinations of imaginary lines in horizontal or vertical directions, and the levels to understand the shape and size of land features.

Plane surveys are conducted for small areas, considering the Earth to be flat and assuming the north-south lines are parallel.

Surveys for buildings, farms, and most constructed works are plane surveys.

On the other hand, geodetic surveying takes the curvature of the Earth into account, making it applicable to smaller and larger areas.

Large surveys such as marking national boundaries, are carried out using geodetic surveying.

Both plane and geodetic surveys use elevations as vertical distances above or below mean sea level. 

Surveying is also used to measure the quantities of materials in construction works, such as earthwork, for cost calculations.

Additionally, surveying involves aligning highways along predetermined directions and plotting capacity contours for proposed reservoirs.