For calculating areas of polygons by means of projecting to a cylindrical equal area projection I came across the following discrepancy:
Distance calculated by Integrated Elliptic Circumference:
Distance calculated by Simple Elliptic Circumference Calculation:
10001.973km (very close to source above)
- Difference: 5.586km (~0.056%)
The WGS84 ellipsoid definition (pdf) (Chapter III) doesn't specify this.
Is the integrated solution of 10007.559km more precise?
I'm referring to the exact circumference of the ellipse intersecting the WGS84-Ellipsoid at the two poles and the equator where a (semi-major axis) and b (semi-minor axis) are defined by the WGS84-ellipsoid definition
The distance of pole to equator is a quarter of that circumference (blue line in sketch).
I'm aware that the original meter definition of it was a 10 000th of this distance.