Introduction Definition of surveying: the science, art and technology of determining the relative positions of points above, on, or beneath the earth’s surface. Its earliest application were in measuring and marking boundaries of property ownership. Definition of surveyor: A surveyor is a professional person with the academic qualifications and technical expertise to conduct one, or more, of the following activities; * to determine, measure and present the land. Three-dimensional objects, point-fields and trajectories.

to assemble and interpret land and geographically related information to use the information for the planning and efficient administration of the land, the sea and any structures. to conduct research into the above practices and develop them.

History of surveying The oldest historical records in existence today is began in Egypt. Construction of irrigation system. Establish and control landmarks (after the yearly flood of the Nile) building huge pyramids Example of instruments: To level the foundations: Either poured water into long, narrow clay troughs or used triangular frames with plumb bobs.

Plumb line Ancient levelling frame

General classification of surveys: If the area that you are interested in is small enough, the techniques of Plane surveying are used. That is to say you have horizontal planes and straight vertical lines parallel to each other. Therefore, surveys for farms, subdivisions, buildings, mines, and in fact most of constructed works are plane surveys. Plane surveys are not considered to be sufficiently accurate for establishing stat and national boundaries. Geodetic surveys are those that are adjusted for the curved shape of the earth’s surface. (the earth is an oblate spheroid whose radius at the equator is about 13.5 miles greater than its polar radius).

Main features of Geodetic surveys It can be applied to both small and large areas. The equipment used and the methods of measurement are about the same as they are in plane surveys. However, they differ principally in the assumptions on which the computation are based. Most geodetic surveys are made by government. it is used to establish a network of reference pointes throughout the world that provides very precise information on horizontal and vertical locations

Importance of surveying All types of engineers, as well as architects, foresters, and geologists are concerned with surveying as mean of: Map the earth above and below see level Prepare navigational charts for use on the air, on land and at sea. Establish property boundaries of private and public lands. Develop data banks of land use to manage the environment. Determine facts on the size, shape and magnetic fields of the earth. Prepare charts of our moon and planets.

Types of surveys 1. Land surveys - Normally plane surveys - mad for locating property lines - subdividing land into smaller parts - determine land areas. etc. 2. Topographic surveys: - determine locations of natural and artificial features and elevations used in map making. 3. Control surveys: - establish a network of horizontal and vertical points and their horizontal and vertical positions are accurately determined. - other points can conveniently be referenced or oriented to them.

4. Mine surveys: - to obtain the relative positions and elevations of surface and underground constructions such as shafts, tunnels, geological information and so on. - to determine quantities - establish lines and grades for work to be done. 5. Remote sensing: - use cameras or sensors that are transported in aircraft or in artificial satellites. 6. Construction surveys: - to locate structures - providing required elevation points during their construction