A Bayesian Benchmarking of GBEES Applied to Outer Planet Orbiter Estimation

Abstract

Moment-based estimation filters have successfully aided spacecraft navigation for decades. However, future missions plan to venture into deep-space regimes with significant round-trip light-time telecommunication delays, operate in unstable, quasi-periodic orbits, and perform highly precise, low-altitude flybys of outer planet moons. These complex trajectories may necessitate ensemble-based filters for accurate estimation over realistic measurement cadences. To mitigate the inherent risk associated with testing novel navigation software, ensemble filters must be accurate, efficient, and robust. Grid-based, Bayesian Estimation Exploiting Sparsity, a high-dimensional Godunov-type finite volume method that propagates the full probability distribution function, demonstrates strong overall performance across all these criteria when compared with the contemporary landscape of filters. These qualities are exhibited via a Bayesian investigation in which the state uncertainty of a Saturn-Enceladus Distant Prograde Orbit is propagated, incorporating infrequent, nonlinear measurement updates. Along with root mean square error, we use the Bhattacharyya coefficient, a non-normal metric for measuring the dissimilarity between distributions, and the Effective Sampling Size, a measure of particle degeneracy, to quantitatively ascertain that in this application, Grid-based, Bayesian Estimation Exploiting Sparsity outperforms the other ensemble filters assessed, though it comes at a nontrivial computational cost.