Surveying is the science of representing the layout of the land accurately on maps or plans, and indicating the exact position of any structure or other man-made or natural object, above or below ground.
Surveying plays a vital role in the planning, provision and maintenance of all forms of construction and development.
Surveying comprises mainly two fields:
Topographical surveying entails the gathering of information to map the forms of the earth. This is done by means of: triangulation (measuring of angles); traversing; levelling (determining of heights); aerial photographs; calculating positions and heights; establishing place names; annotating aerial photographs by indicating the topographical features.
Back in the office, the surveyor applies this information to the task of preparing a detailed land map. A photogrammetric machine is used to assist in the process.
Engineering surveying entails the collection of all relevant information on the site of a proposed construction project and mapping out the area. Once the design of the project is complete, the surveyor pegs it out on the actual site and also monitors construction in progress to ensure that it does not exceed the layout.