Work out area by double meridian distance instantly with clear inputs, formula shown and shareable results.
The double meridian distance method computes traverse area directly from latitudes and departures without needing coordinates. Each leg's DMD is the previous DMD plus the previous and current departures, and multiplying by the latitude and summing gives twice the area. The closure error of the legs is reported because a poorly closing traverse gives an unreliable area.
Double meridian distance
DMD of a leg = DMD of the previous leg + departure of the previous leg + departure of this leg
Area
Area = 0.5 x |sum of (DMD x latitude)|
DMD of a leg = DMD of the previous leg + departure of the previous leg + departure of this leg. The double meridian distance method computes traverse area directly from latitudes and departures without needing coordinates.
It was the standard hand method because it works straight from the bearing and distance reductions with no coordinate computation. It remains a useful independent check on a coordinate-based area.
This calculator takes 2 inputs: Traverse legs as latitude,departure pairs, Scale factor applied to the values. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.