In Bowditch rule of traverse adjustment, it is assumed that errors in the linear measurements are (where L is the length of a line)
- AProportional to √LCorrect
- BProportional to L
- CInversely proportional to √L
- DInversely proportional to L
Solution
Concept
Assumption behind Bowditch's rule
Formula
Correction to latitude of a line = (ΣL / total perimeter) × l
Step-by-step solution
1. Bowditch's (compass) rule assumes that errors in linear measurement are proportional to √L. 2. Errors in angular measurement are assumed to be inversely proportional to the length of the line. 3. The correction is applied in proportion to the length of each line.
Explanation
Bowditch's rule is used when linear and angular measurements are of equal accuracy. It assumes the linear error varies as √L, and the correction to latitudes and departures is distributed in proportion to the length of the sides.
Shortcut
Bowditch rule: error ∝ √L; correction ∝ L (length of the side).
Common mistake
Confusing the assumption (√L) with the way the correction is applied (proportional to L).
Correct answer: A) Proportional to √L