Orientation of a Plane Table by Solving Two Point Problem:

In plane table surveying, the orientation of the table is determined by taking the bearings of two known points. The process is known as the two-point problem. Here, we will discuss when the orientation of a plane table is adopted by solving the two-point problem.

When are the two-point problems used in plane table surveying?

The orientation of a plane table by solving two-point problems is adopted when the given points are inaccessible. The following are the reasons why two-point problems are used in plane table surveying:

1. Inaccessibility of Points:

The two-point problem is used when the given points are not accessible. In such cases, the surveyor cannot place the table over the given points. Hence, the surveyor takes the bearings of the two known points from a nearby location where the table can be set up.

2. Time-Saving:

The two-point problem is a quick and straightforward method of orienting the plane table. The surveyor does not have to traverse the entire survey area to orient the table. Instead, the bearings of two known points are taken, and the table is oriented in a matter of minutes.

3. Better Accuracy:

The two-point problem is used when better accuracy is required in the survey. The orientation of the plane table is critical in obtaining accurate measurements. By taking the bearings of two known points, the surveyor can ensure that the table is oriented correctly, which leads to accurate measurements.

Conclusion:

The orientation of a plane table by solving the two-point problem is a simple and quick method of orienting the table. It is used when the given points are inaccessible, and time-saving and better accuracy are the main factors. The surveyor must ensure that the two known points are visible from the setup location and are well-distributed in the survey area.