Orientation by using Trough Compass |
In this method, the edge of the trough compass is placed along the magnetic meridian (drawn at the starting station) and the plane table is rotated till the needle points to zero-zero of the scale. Once it is achieved, the table is said to be oriented and thus clamped. This method of orientation is not very accurate and also may get affected by local attraction and is generally used for small-scale survey. |