hyperbolic orbit math question

[ncc1701d]

just learning hyperbolic orbits. Can some expert explain what f means in this formula? I know eliptical orbits math but dont understand where f comes from with hyperbolic orbits. See image

 

[Thorsten]

f would seem to be the true anomaly of the orbit.

 

[ncc1701d]

the diagram made me think that v (upsilon) was true anomaly

 

[Urwumpe]

the diagram made me think that v (upsilon) was true anomaly

Yes, in the diagram. But in the formula below, it seems to be f. It looks very much like the classic orbit equation.




https://en.wikipedia.org/wiki/Kepler_orbit#Johannes_Kepler