florisvdh
commented
1 year ago did you check the calculation against a known result (from a text book maybe)?
No, I just applied the formulas from text books. But in fact what you propose should be quite easy to verify, computing distances with S2 on the sphere and compare that with distances in a projected CRS with GEOS. I will try to do that.
The two proposed functions calculate the distance distortions (scale factors) in the most used projection methods.