Modern Astrodynamics

2

Gauge Freedom in Astrodynamics

MICHAEL EFROIMSKY     US Naval Observatory.

Contents

2.1. Introduction

2.2. Gauge freedom in the theory of orbits

2.3. A practical example on gauges: a satellite orbiting a precessing oblate planet

2.4. Conclusions: how we benefit from the gauge freedom

Appendix 1. Mathematical formalities: Orbital dynamics in the normal form of Cauchy

Appendix 2. Precession of the equator of date relative to the equator of epoch

References

2.1 Introduction

2.1.1 What this chapter is about

Both orbital and attitude dynamics employ the method of variation of parameters. In a non-perturbed setting, the coordinates (or the Euler angles) get expressed as functions of the time and six adjustable constants called elements. ...