Technical Terms:

Survey Stations

These are significant point fixed on ground indicating the beginning point and the end point of the survey line. These are additionally basic control points of the survey. There could be two types of survey stations.

Main Station

Main stations are worked as a control points at the ends of the chain lines commanding the boundaries of survey.

Subsidiary or Tie Station

These are stations selected on a main survey lines for running auxiliary lines drawn to plot interior details and locate measure. (Figure)

Figure: Layout of Chain Survey

The survey stations are suitably selected with care so that at least main survey stations are mutually visible and survey lines run through as flat ground as possible and are as close to the boundaries as possible. A main survey lines should form well conditioned triangles. These should be as some as probable and suitably selected so as to avoid obstacles in chaining and ranging.