Plane Table Surveying by Intersection method, All equipment used in plane table Survey

Plane Table Surveying * Plane table consists of a board made up of a well seasoned wood mounted on a light tripod with suitable mounting and clamping devices. The table is to be levelled by adjusting tripod. * Accessories for plane table required are: 1. Alidade or sight rule—plain or telescopic 2. Plumbing fork with plumb bob 3. Spirit level 4. Trough compass 5. Drawing sheet and accessories for drawing. * Working operations are centring, levelling and orientation. Orientation may be achieved by using trough compass, back sighting or by solving two-point or three-point problems. * Method of plane tabling are radiation, intersection, traversing and resection. * The problem of finding plotted position of the station point occupied by plane table with the help of two well defined points, the plotted position of which are known, is called two-point problems. Similarly, three-point problem is the problem of locating station point with the help of three plotted positions is known as three-p...