UKPSC (Urban Engineering) 2012 / Uttarakhand Combined State A.E. 2001 / UPPSC A.E. 2003 / ESE 2011
⭕ A. Tracing paper method
⭕ B. Bessel's method
⭕ C. Lehman's method
⭕ D. All of these
📚 Explanation:
The **three-point problem** in plane table surveying involves locating the position of the plane table by sighting three known points.
This problem can be solved by the following methods:
🔹 Bessel's Method (Graphical method)
Graphically determines the correct orientation and position.
🔹 Tracing Paper Method (Mechanical method)
A tracing sheet is used to rotate and match plotted rays.
🔹 Lehman's Method
An iterative approach that gradually improves the estimated location.
All these techniques are recognized and widely used, hence the correct choice is:
The **three-point problem** in plane table surveying involves locating the position of the plane table by sighting three known points.
This problem can be solved by the following methods:
🔹 Bessel's Method (Graphical method)
Graphically determines the correct orientation and position.
🔹 Tracing Paper Method (Mechanical method)
A tracing sheet is used to rotate and match plotted rays.
🔹 Lehman's Method
An iterative approach that gradually improves the estimated location.
All these techniques are recognized and widely used, hence the correct choice is:
👉 Therefore, the correct answer is: D. All of these
Key Points about Three-Point Problem:
- Bessel’s method: Graphical solution.
- Tracing paper method: Mechanical solution.
- Lehman’s method: Iterative refinement.
