Sphere or Ellipsoid?

X-no-archive: yes
In article , Pat Russell
writes
Which distance calculation algorithm is used by FAI in the homologation of
gliding world records?

-Pat

Either the FAI sphere or the WGS84 ellipsoid. But where the distance is
critical, the WGS84 ellipsoid is used.

There is a script for calculating WGS84 distances at:
http://www.fai.org/distance_calculation/

For more info read the Sporting Code (General section).

Para 7.3.1.1, states: "For FAI distance calculations, the earth model
used may either be the WGS84 ellipsoid or a sphere of radius 6371 km
exactly. For accurate measurement and calculation of distance, Air Sport
Commissions shall choose which model is to be used in their area of
activity. The WGS84 ellipsoid is very close to the real shape of the
earth, the FAI sphere is an approximation."

Sporting code Section 3 (Gliding) Para 4.4.1 says:

"For the purpose of the calculation of FAI geodesic distances, the WGS84
earth model shall be used. See also Annex C, Appendix 2.

When calculation of the exact distance is not critical, less accurate
methods may be used. See Annex C , para 1.6b."

Best regards,

Tim Newport-Peace

"Indecision is the Key to Flexibility."