Survey regulations in Western Australia require that a traverse must be adjusted by the Bowditch method prior to any area calculation. This method of adjustment has a long history and is used only to ensure that the area calculations are calculated on a closed figure.

• Only the DE and DN values are adjusted.
• No attempt is made to adjust the input bearings and distances.

The theory of the adjustment is that each DE and DN receives an adjustment in proportion to the length of the line divided by the total perimeter length of the survey. View the animation below.

The closure procedure

The correct procedure for carrying out a traverse closure using the Bowditch method can be found by clicking here.

You can control the movie using the movie controller. The play button will start the movie and the other buttons can be utilised to cue or restart the animation as desired.