Trigonometric Leveling is the branch of Surveying in which we find out the vertical distance between two points by taking the vertical angular observations and the known distances. The known distances are either assumed to be horizontal or the geodetic lengths at the mean sea level(MSL). The distances are measured directly(as in the plane surveying) or they are computed as in the geodetic surveying.
The trigonometric Leveling can be done in two ways: (1) Observations taken for the height and distances (2) Geodetic Observations. In the first way, we can measure the horizontal distance between the given points if it is accessible.
We take the observation of the vertical angles and then compute the distances using them. If the distances are large enough then we have to provide the correction for the curvature and refraction and that we provide to the linearly to the distances that we have computed.
In the second way, i.e geodetic observations, the distances between the two points are g…