Suppose a plan is required for a small area . The surveyor must first examine the land to determine how the work can best be arranged. This is known as a reconnaissance survey. In this process, the surveyor selects suitable ground points to be used as stations such as A, B, C, etc.
Stations are arranged so that the entire area may be controlled from these points and all the main survey lines AB, BC, CD, etc. run near to the boundaries. The survey lines should not be many and lie over flat level grounds as far as possible. The triangles formed by survey lines should be well conditioned.
The main survey lines are measured with a chain and offsets are taken to the boundaries. Offsets are taken wherever there is a bend or any special feature in the boundary. In cases, where the boundary forms a smooth curve offsets are taken at the end of each chain. Offsets should be short, particularly for locating important details.
The lengths and positions of offsets being known, the boundaries can be plotted to their shapes. The other details which are deep inside the area, can be located by selecting tie stations, drawing tie lines and taking offsets to the ground features.
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