Procedures of Chain Surveying:
Principle
The principle of chain surveying is derived from principle of triangulation. The overall area to be surveyed is divided within framework of triangles of appropriate sizes. Network of triangles is selected as these are simple geometrical figures that can be simply plotted along with the measurements of its sides only. It is advisable to use well conditioned triangles whose sides are as nearly equivalent as possible along with angles among 30o to 120o. That shaping of triangles result in higher accuracy. The triangulation of area prevents the need of measuring angles hence can be surveyed and plotted simply by measuring distances through changing alone.
The chain survey is preferred while the ground is nearly flat and open (preventing crowded areas along with many details, or areas which are heavily wooded or undulating) and also while the area to be surveyed is smaller.