Question

In which of the following methods of Plane Table Survey, it is required to go to the plotted station in resection?
1. Intersection
2. Two point problem
3. Three point problem
4. Back ray method

Answer 1

Correct Answer - Option 4 : Back ray method

Explanation

Resection: It is a method of orientation employed when the table occupies a position not yet located on the drawing sheet. It is defined as the process of locating the instrument station occupied by the plane table by drawing rays from the stations whose positions have already been plotted on the drawing sheet.

Methods of resection

1. Compass Method
2. Back ray Method
3. Resection by two points (two points problem)
4. Resection by three points (three points problem)

Back Ray Method:

• This method can be used only if the plane table Station (C) is already selected and a ray has been drawn from one of the stations (say A or B) towards station C but the exact location of station C is not marked on the ray. 

Two-point problem is used for determining the location of the station occupied by the plane table.