In regard to the resection method of plane table survey, the term 'resector' refers to the:
- Arays drawn from the un-plotted location of the station to the un-plotted location of the points
- Brays drawn from the known location of the station to the known location of the points
- Crays drawn from the un-plotted location of the station to the known location of the pointsCorrect
- Drays drawn from the known location of the station to the un-plotted location of the points
Solution
Concept
A resector is a ray drawn from the unknown (un-plotted) station to a known (plotted) point.
Step-by-step solution
1. In resection, the table is set at a new station whose position is not yet plotted. 2. Known points are already plotted on the sheet. 3. A ray drawn through the plotted known point towards the unknown station is called a resector. 4. So the resector goes from the un-plotted station to the known (plotted) point. Answer is C.
Explanation
In resection we find the position of the table station using already plotted points. The ray that links the unknown station position with a known plotted point is called a resector. Back rays from two or more such points meet at the station position.
Why the other options are wrong
A: the points are already known, not un-plotted. B: if the station were already known, no resection would be needed. D: this reverses the case, because the station is the unknown and the points are known.
Shortcut
Resection means finding your own position, so the station is unknown and the points are known.
Common mistake
Mixing up a resector with a radial ray, which is drawn from a known station in the radiation or intersection method.
Correct answer: C) rays drawn from the un-plotted location of the station to the known location of the points