# What is the two-point problem in the surveying

Techno Upendra

The two-point problem consists in locating the position on the plan of the station occupied by the plan table. The observation of two well-defined points.which are visible from the instrument station and who's position has been already plotted on the plan are selected. then by perfectly bisecting these points, a new station is established at the required position.
plane table survey

Procedure:- Suppose P and Q are two well -defined points whose positions are plotted on map and q.  It is required to locate a new station at A by perfectly bisecting P and Q.
i. An another station B is selected on the ground, which is visible of A.
ii. Set the plane table at B, with touch of p and q  bisect the P and Q with the help of alidade.
iii. Alidade is centre on b bisect the point a1.
iv. Set the table on A. Bisect the point P along p and ray is drawn, same method Q and q drawn.
v. The alidade is placed along the line PQ and the table is turned to bisect R. at this position the table is said to be p[erfectly oriented.
vi. The alidade is centre on p and q, the points P and Q and bisected and rays are drawn. These rays intersected at a point a. This would be the exact position of A.

USES.

A.    For  established survey station for contouring, a method used in the total station,