The Surveying reference article from the English Wikipedia on 24-Apr-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Surveying

Surveying is the branch of engineering that is concerned with the accurate measurement and position of points on the Earth's surface, and to the establishment of boundaries. It basically achieves this by measuring the relative horizontal and vertical position of points on the ground, aided by a theodolite or a similar optical instrument.

Surveying has been an essential element in the development of the human environment for many centuries and it is a requirement in the planning and execution of nearly every form of construction. Its principal modern uses are in the fields of transportation, building, apportionment of land, and communications.

Table of contents

1 Origins 2 Types of surveys 3 Modern surverying 4 Surveying as a career 5 Famous surveyors 6 External Links

Origins

Surveying can be traced back to the Egyptians, who, every year after the Nile River overflowed its banks and washed out farm boundaries, would fix new boundaries by surveying. The nearly perfect squareness and north–south orientation of the Great Pyramid of Giza, built c. 2700 BC, affirm the ancient Egyptians' command of surveying.

Types of surveys

• Boundary survey: The actual positions of existing marks on land (typically iron rods or concrete monuments in the ground, but also tacks in trees, pipes, and manholes) are measured, and a map is drawn from the data.
• Subdivision plat: Given a survey of a parcel of land, lines are drawn inside it, indicating where roads and lots are. Plats are usually discussed back and forth between the developer and the surveyor until they are agreed on, at which point pins are driven into the ground to mark the lot corners and curve ends and the plat is recorded in the county cadaster (USA) or land registry (UK).
• Draw lot: One lot from a plat is drawn, with any easements and setbacks that may be on it.
• Plot plan: A proposal for a house or other building and driveway or parking lot are added to a draw lot.
• Foundation: The position of the house is measured before it is finished being built.
• Physical: The finished house and driveway are measured, and all markers on the boundary are indicated. This is recorded when the lot is sold.

Modern surverying

Modern surveying utilizes an instrument called a total station, a small telescope equipped with an electronic distance-measuring device and set up on a tripod, although the modern use of satellite positioning systems, such as GPS, is also well established.

Surveying as a career

Modern surveying is closely connected with the various branches of engineering, especially civil engineering. Surveyors find work to do whenever there are roads, dams, bridges, and residential areas to be built. They determine the boundaries of private property and the boundaries of various political divisions. They also provide input for geographical information systems (GIS), computer databases that contain data on land features and boundaries.

Surveyors must have a thorough knowledge of algebra, basic calculus, geometry, and trigonometry. They must also know the laws that deal with surveys, property, and contracts. In addition, they must be able to use delicate instruments with accuracy and precision.

Famous surveyors

• George Washington
• Liu Hui
• John Ericsson
• Charles Mason and Jeremiah Dixon

External Links

• U.S. Geological Survey

This is the "Surveying" reference article from the English Wikipedia. All text is available under the terms of the GNU Free Documentation License. See also our Disclaimer.