Hybrid Particle Gaussian Mixture (H-PGM) Solution for Cislunar Target Tracking

2026-06-02

AI Summary

This study addresses the limitations of traditional Gaussian orbit determination methods, which rely on the two-body Keplerian assumption and struggle to handle the strong nonlinear three-body dynamics and out-of-plane effects prevalent in cislunar space. To overcome these challenges, this work proposes a hybrid Particle Gaussian Mixture (H-PGM) recursive probabilistic orbit determination framework. It uniquely integrates, in a sequential manner, an MCMC-driven PGM-II filter with a Kalman-updated PGM-I filter, effectively fusing angle-only observations with prior information. The resulting approach establishes a fully recursive probabilistic tracking mechanism tailored for the Earth–Moon three-body environment. Evaluated across multiple representative orbital scenarios, the method demonstrates substantial improvements in both accuracy and robustness, significantly outperforming existing homogeneous and hybrid filtering techniques.

Abstract

Gauss's method of orbit determination (OD) is one of the most popular, minimal assumption target tracking techniques in astrodynamics, especially for generating an initial state estimate. However, due to Gauss's method's assumption of Keplerian motion (part of the larger two-body problem), this method cannot be applied in a cislunar environment, where three body, non-planar effects dominate. In this work, we showcase a hybrid Particle Gaussian Mixture (H-PGM) filtering method, a purely recursive probabilistic OD framework that relies upon a sequential combination of the Markov Chain Monte Carlo (MCMC) based Particle Gaussian Mixture-II (PGM-II) and Kalman update based Particle Gaussian Mixture-I (PGM-I) filters. This method allows us to fuse probabilistic information with angles-only observations from terrestrial telescopes for short- and long-term cislunar target tracking. This method also allows us to fuse other target \textit{a priori} information in an effort to reduce target uncertainty in the short term. This hybrid filtering technique is demonstrated for several popular and important cislunar orbit regimes and compared with several homogeneous and hybrid filtering frameworks.

Problem

• cislunar target tracking
• orbit determination
• Gauss's method
• three-body problem
• angles-only observations

Innovation

• Hybrid Particle Gaussian Mixture
• Cislunar Target Tracking
• Orbit Determination
• Probabilistic Filtering
• Angles-only Observations