Change Point in Surveying

In surveying, a change point refers to a point along a survey line where the direction of the line changes. This can happen due to various reasons such as a change in the terrain, obstacles in the way, or a change in the purpose of the survey.

Sights Applicable for Change Point

The sights that are applicable for a change point are:

Back Sight: A back sight is taken on a point with a known elevation, which is used as a reference point for the rest of the survey. This sight is taken from the change point to the reference point.

Fore Sight: A fore sight is taken on a point that needs to be surveyed and whose elevation is unknown. This sight is taken from the reference point to the change point.

Back Sight and Fore Sight: Both back sight and fore sight are applicable for a change point, as they are used to establish the elevation of the change point. The back sight is taken on a reference point with a known elevation, and the fore sight is taken on a point whose elevation is to be determined. The change point is the point where the direction of the survey line changes.

Intermediate Sight: An intermediate sight is taken on a point between the reference point and the change point. This sight is used to check the accuracy of the survey and to ensure that the line is straight.

Conclusion

In conclusion, the sights that are applicable for a change point in surveying are back sight, fore sight, and intermediate sight. These sights are used to determine the elevation of the change point, establish the reference point, and ensure the accuracy of the survey.