Traverse misclose calculator
Calculate closed-loop or link traverse misclose, whole-circle misclose bearing, precision ratio and Bowditch adjusted survey coordinates.
This tool runs in your browser and nothing you enter is uploaded. Check results independently before relying on them for survey work.
How it works
Each leg contributes ΔE = d sin θ and ΔN = d cos θ. Misclose is computed endpoint minus known closing point; its bearing points from the known close to the computed endpoint. Precision is total length divided by linear misclose. Bowditch distributes the negative misclose in proportion to each leg length. It assumes comparable angular and distance precision; no angular adjustment is performed.
Worked example
Start at (1000,1000), then book 0°,100 m; 90°,100 m; 180°,100 m; 270°,99 m. The computed endpoint is (1001,1000), so misclose is 1.000 m at 090°00′00″ and precision is 1 : 399. Each 100 m leg receives −0.250627 m easting correction; the 99 m leg receives −0.248120 m. The adjusted traverse closes at (1000,1000).
Sources and further reading
For recommended equipment and procedures for control traverses, with examples of evaluating the uncertainty of the coordinates, see ICSM’s Guideline for Conventional Traverse Surveys, part of the Standard for the Australian Survey Control Network (SP1).
Frequently asked questions
What is the difference between a loop and a link?
A loop closes back to its starting coordinates. A link ends at a different known point; enter that point in both closing coordinate fields.
Which way does the misclose bearing point?
From the known closing point towards the computed endpoint. Bowditch applies corrections in the opposite direction.
Does Bowditch fix all traverse errors?
No. It distributes coordinate misclose by leg length. Check observations, orientation, control and blunders independently before adjusting.
How is exact closure displayed?
A misclose smaller than 0.000000001 m is treated as numerical closure. The precision is shown as exact closure rather than an infinite ratio.
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