Hello dear forum members,
I have a question regarding the ApsideDetector. For my work, I require a very precise determination of the time of the next occurring perigee or apogee. Therefore, my question is which calculation method is used to determine the apsides. Is it based on the short-term average method?
Kind regards,
Max
No, it is based on the dot product of position and velocity, hence it is zero when they are orthogonal at apsides. The sign change is from negative to positive at perigee and from positive to negative at apogee. It is therefore an instantaneous (or osculating) computation.
Hello
To not state the obvious, but I had struggle in the past with that, being the dot product of osculating vectors, it might change sign multiple times for a near circular orbit, so to capture events very far from the theoretical argument of perigee concept.
Is there a new solution with the new average orbit methods since Orekit 13.x?
Thanks
Alberto
Well, for near circular orbits, apsides are inherently unstable.