Intersection Method of Plane Table Surveying
Select two instrument stations P and Q, such that all the points or details to be located are visible from both the stations. Now set the table on P and make it centered and level. Using the plumbing form locate the ground station on the sheet i.e. p, such that the point p on the sheet is exactly over the point P on the ground. Measure the distance between PPhysical Features of the Earth
Physical features map include the existence of: Mountains Rivers Slope or plain area Atmospheric study consists of: The average temperature of the site Average rainfall Climate of the area Wind and floodsGround Control
In order to produce an accurate map from aerial photograph it is absolutely necessary to established ground control. It consists in locating the positions of a no of pts. All over the area to be surveyed det their levels. These control pts short be such that can be easily identified on the photographs.Surveying Dictionary Words Definitions Starting from M, N, O, P
Magnetic declination is the horizontal angle between true north (i.e., the geographic meridian) and magnetic north (i.e., the magnetic meridian). There are two conventions for specifying the angle. One is to indicate the magnitude (e.g., 6o) and direction as E or W of north. The other considers positive values to be toward the east and negative values to be toward the west.
