2. Compass Rule

The Compass Rule (also known as the Bowditch Rule) applies a proportion of the closure error to each line.

For any line IJ, Figure E-3,

Figure E-3
Adjusted Latitude and Departure


img20      Equations E-1 and E-2


img21       Equations E-3 and E-4


The Compass Rule distributes closure error based on the proportion of a line's length to the entire distance surveyed.