The Formulae on the ellipsoid spreadsheet [107.5 KB] has the ACT Ellipsoid's parameters added (a=6,378770m, f=1/298.25). The formulae are those of Vincenty.

If you have the azimuth and spheroidal distance, you can calculate:

  • latitude and longitude
  • reverse azimuth from a mark.

If you have the latitude and longitude of two marks, you can calculate:

  • spheroidal distance
  • forward and reverse azimuths between them.