Question

The process of determining the plotted position of the station occupied by the plane table by means of sights taken towards points of known location is called :
1. Resection
2. Intersection
3. Orientation
4. None of these

Answer 1

Correct Answer - Option 1 : Resection

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.

It can be conducted by:

1. Resection by compass
2. Resection by back sighting
3. Resection by two points (two points problem)
4. Resection by three points (three points problem)

Methods:

1) Radiation method:

• It is adopted when the points to be plotted are intervisible and accessible from a single instrument station. Orientation is not required because only one instrument station is required.

2) Intersection method:

• It is adopted when the points to be plotted are intervisible but inaccessible. Orientation is required

3) Traversing method:

• The traverse is directly plotted on the paper by drawing the traverse lines with the alidade. No angle measuring instrument is used.