To decide on the best skeletal framework plan for surveying a field, one must base one’s decision on the least effort required to produce a map with the desired detail and minimum distortion. . The following points should be kept in mind:Through reconnaissance it should be ascertained that due to the presence of thick hedges, trees or any other obstacles, there should not be any obstruction to the laying of chain along the framework, taking the necessary measurements and the intervisibility along the lines of the framework.
Preferably a long line should run through the centre of the area to form a base line on which well-conditioned triangles should be based. The base line should prevent the relative rotation of the triangles due to error in the measurements when they are plotted in the map. This arrangement for the framework will limit the distortion in the map to a minimum.
The lines should run closer to the details, which are to be described with respect to them by taking lateral measurements called ‘offsets’.
To avoid long offsets additional lines should run between the sides of the triangles of the framework.
There should also be some other additional lines for checking the accuracy of the measurements.
Care should be taken so that no portion of the framework goes beyond the boundary of the area to be surveyed.
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