How to calculate distance between two points on earth?

Question

.NET

Good afternoon,
2 points for each coordinate lat, lon
How to calculate the distance between them?
I saw there is a .net Framework GeoCoordinate method, but I do it on .net core

Answer 1

There are several options, in order of increasing accuracy and "correctness":
1) The length of the segment multiplied by the dimension of 1 degree in meters, i.e. e.g. 30 km by 17 degrees → sqrt((1.76Δlat)^2+(1.76Δlon)^2)
2) As above, but different scales in lon and lat.
3) The length of the arc on the sphere.
4) The length of the arc on the ellipsoid.
5) The length of the arc on a certain ellipsoid, the most accurate for the terrain. The Carney distance (there is a link to ready-made libraries in different languages) on the WGS84 ellipsoid gives a good accuracy of 1-2 meters.
6) Calculation by geoid or local map. I can’t say anything here, because this is an overhead projector a little more than always.

Answer 2

the length of an arc on a sphere.
Elementary school stereometry.
Already completely lazy

Answer 3

On nuget.org dangles the same name with source codes inside - as many as two files.