Robust resolution of Kepler’s equation in all eccentricity regimes

Abstract

In this paper we discuss the resolution of Kepler’s equation in all eccentricity regimes. To avoid rounding off problems we find a suitable starting point for Newton’s method in the hyperbolic case. Then, we analytically prove that Kepler’s equation undergoes a smooth transition around parabolic orbits. This regularity allows us to fix known numerical issues in the near parabolic region and results in a non-singular iterative technique to solve Kepler’s equation for any kind of orbit. We measure the performance and the robustness of this technique by comprehensive numerical tests.