In-plane table operation: Orientation

Orientation is the operation that must be carried out on an in-plane table. This operation is essential for establishing the correct position and direction of a survey station or point.

Explanation:
- In-plane table is a surveying instrument used for recording field observations and performing calculations. It consists of a drawing board with a transparent overlay and a set of instruments such as a protractor, rulers, and pencils.
- The in-plane table is used for various surveying tasks, including traversing, leveling, and plotting.
- When conducting a survey using an in-plane table, the first step is to establish the correct orientation of the table.
- Orientation refers to aligning the in-plane table with the true north direction or a known reference direction.
- By orienting the table correctly, the surveyor ensures that all subsequent measurements and calculations are referenced to a consistent direction.
- This is crucial for accurate plotting and analysis of survey data.
- Orientation can be achieved using various methods, such as using a compass, known reference points, or astronomical observations.
- Once the table is properly oriented, the surveyor can proceed with other operations such as resection, radiation, or intersection.
- Resection involves determining the coordinates of an unknown point by measuring angles and distances from two or more known points.
- Radiation refers to measuring angles and distances from a known point to locate an unknown point.
- Intersection involves determining the position of an unknown point by measuring angles from two or more known points.
- While these operations are important for surveying, they can only be performed accurately if the in-plane table is correctly oriented.

Conclusion:
In summary, when using an in-plane table for surveying, the operation that must be carried out is orientation. This involves aligning the table with a known reference direction to ensure accurate plotting and measurement of survey data.