Haversine formula

Explanation:
https://en.wikipedia.org/wiki/Haversine_formula

  1. Fill in lat1 and lon1
  2. Fill in lat2 and lon2
lat1 ie 46.24298 for pole
lon1 ie 0.23735 for pole
lat2 ie 46.24288 for B4 on pole
lon2 ie 0.23754 for B4 on pole
dlat in units PI/180
dlon in units PI/180
dlat_meters
dlon_meters
distance_meter