Orbit Elements from Kepler Solutions in Projective Coordinates
arXiv:2511.12957
Abstract
Closed-Form Kepler solutions in projective coordinates are used to define a corresponding set of eight orbit elements and obtain their governing equations for arbitrarily-perturbed two-body dynamics. The elements and their dynamics are singularity-free in all cases besides rectilinear motion (when angular momentum vanishes). The classic J2-perturbed two-body problem is developed and used for numerical verification.
New in most recent version: corrections to previous inconsistent and misleading notation