DEFINITION:
Surveying is the science and art of making all essential measurements to determine the relative position of points or physical and cultural details above, on, or beneath the surface of the Earth, and to depict them in a usable form, or to establish the position of points or details.
OBJECTIVE OF SURVEYING:
The aim of surveying is to prepare a map to show the relative positions of the objects on the surface of the earth.
To collect field data.
To prepare plan or map of the area surveyed.
To analyze and calculate the field parameters for setting out operation of actual engineering works .
To set out the field parameters at the site for further engineering works.
GENERAL PRINCIPLE OF SURVEYING:
The general principles of surveying are:
1. To work from the whole to the part
2. To locate a new station by at least two measurements (linear or angular) from fixed reference points.
The purpose of working from whole to part is “to localise the errors and to control the accumulation of errors”.
According to the first principle, the whole survey area is first enclosed by main stations and main survey lines. The area is then divided into a number of divisions by forming well conditioned triangles.
Example of work from the whole to the part
