49 50 Ver6.09.hp Geodesic distance & Earth Euclidean distance calculator, bearing

[Gil]

Nearly antipodal points

For distance and forward / backward calculation
P1P2—>s, or inverse problem, of nearly antipodal points, the basic idea would be to use the direct solution P1—>P2, in a modified version, of course.

We give then the initial point 1 (lat1, lon1) and final antipodal point 2 (lat 2, lon 2) and try to reach that last point, via a modified P1—>P2 program, just making vary at the same time the distance s and alpha 1.

That should give something of the kind:

'f1mod(P1—>P2(lat1, long1, s, alpha1))=lat2'
'f2mod(P1—>P2(lat1, long1, s, alpha1))=lon2'
2 —>ARRY
's'
'Alpha1'
2 —>ARRY
20000000
Pi/2 —>NUM
2 —>ARRY
MSLV

Still to be done...