WORK FROM WHOLE TO PART

• It is the first principle of surveying.
• By this principle, it means that the surveyor should first establish the large frame work consisting of main control points, accurately.
• In between the large frame work so established, subsidiary small frame works can be established by a relatively less accurate survey. By doing so, the errors in small frame work get localized and are not magnified and thus the accumulation of errors gets confined.
• In the reverse process of working from part to whole, small errors get magnified due to accumulation of errors from small frame work to large frame work.

Locate a point by atleast two measurements

• According to this principle, the new point (station) should always be fixed by atleast two measurements (linear or angular) from a fixed reference point.
• Take two control points A and B and the distance between them is accurately measured. By using A and B, two control points whose positions are already known on the plan, the position of C can be plotted by any of the following methods:

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