Surveying is the art to determine the relative position of object on or below the surface of the earth by measuring horizontal distance between them and prepare a map to any suitable scale. Surveying is the technique of determining the relative position of different features on, above or beneath the surface of the earth by means of direct or indirect measurements and finally representing them on a sheet of paper known as plan or map.
Surveying is divided into two main categories:-
- Geodetic Survey
- Plane survey
1. GEODETIC SURVEYING : It is a process of surveying in which the shape and size of the earth are considered. This type of survey is suited for large areas and long lines and is used to find the precise location of basic points needed for establishing control for other surveys. In geodetic surveys, the stations are normally long distances apart, and more precise instruments and surveying methods are required for this type of surveying than for plane surveying.
2. PLANE SURVEYING: It is a process of surveying in which the portion of the earth being surveyed is considered a plane. The term is used to designate survey work in which the distances or areas involved are small enough that the curvature of the earth can be disregarded without significant error. In general, the term of limited extent. For small areas, precise results may be obtained with plane surveying methods, but the accuracy and precision of such results will decrease as the area surveyed increases in size. To make computations in plane surveying, you will use formulas of plane trigonometry, algebra, and analytical geometry.
Classification based on the object of survey:
Engineering Survey : This is undertaken for the determination of quantities or to afford sufficient data for the designing of engineering works such as roads and reservoirs, or those connected with sewage disposal or water supply.
Military Survey: This is used for determining points of strategic importance.
Mine Survey: This is used for the exploring mineral wealth.
Geological Survey: This is used for determining different strata in the earth’s crust.
Archaeological Survey: This is used for unearthing relics of antiquity.