Surveying or land surveying is the art and science of accurately determining the location of points on the ground or in three dimensions and the distances and angles between them. These points are usually on the surface of the earth and are often used to map or establish the boundaries of land for property rights or governmental purposes.
To accomplish this purpose, surveyors use elements of geometry, engineering, trigonometry, mathematics, physics, and law. Another definition by the American Congress on Surveying and Mapping (ACSM) is to determine the relative location of points and/or physical and cultural details on, over, or under the surface of the earth and to depict them in a usable form or the science and art of making any significant measurement to establish the location of points and/or details.
Surveying has been an integral part of the development of the human environment since the beginning of recorded history (about 5,000 years ago). Surveying is necessary for the planning and execution of almost all construction. The most familiar modern applications include transportation, building and construction, communications, mapping, and defining the legal boundaries of land ownership.
History of surveying
Surveying techniques have existed throughout much of recorded history. In ancient Egypt, when the Nile River flooded and washed away the boundaries of agricultural land, rope stretchers (surveyors) applied simple geometry to re establish the boundaries. The nearly perfect rectangularity and north-south orientation of the Great Pyramid of Giza, built around 2700 B.C., confirms that the Egyptians were skilled surveyors.
In18th century Europe, triangulation was used to construct a hierarchy of networks that allowed point measurements with in a country. The highest hierarchy was the triangulation network. These were densified into networks of traverses (polygons), to which local mapping surveys, usually using measures, corner prisms, and the familiar red and white poles, we retied. For example, in the late 1780s, the Ordnance Survey of Great Britain team led by General William Roy initiated the Principal Triangulation of Great Britain using a specially constructed Ramsden theodolite. The major survey is known as a geodetic survey.