# Orbit Determination for Continuously Maneuvering Starlink Satellites Based on an Unscented Batch Filtering Method

## TL;DR

This paper introduces a new orbit determination method for Starlink satellites that continuously maneuver, using an advanced filtering technique to accurately predict their positions.

## Contribution

The novel integration of unscented transformation with batch filtering and an optimized sampling strategy for orbit determination of maneuvering satellites.

## Key findings

- The method converges reliably within 10 iterations for orbit determination.
- Position predictions achieve root mean square errors under 3 km for 24-hour forecasts.
- Validation with higher-fidelity models confirms improved accuracy and robustness.

## Abstract

Orbit determination for non-cooperative low Earth orbit (LEO) objects undergoing continuous low-thrust maneuvers remains a significant challenge, particularly for large satellite constellations like Starlink. This paper presents a method that integrates the unscented transformation into a batch filtering framework with an optimized rho-minimum sigma points sampling strategy. The proposed approach uses a reduced dynamics model that considers Earth’s non-spherical gravity and models the combined effects of low-thrust and atmospheric drag as an equivalent along-track acceleration. Numerical simulations under different measurement noise levels, initial state uncertainties, and across multiple satellites confirm the method’s reliable convergence and favorable accuracy, even in the absence of prior knowledge of the along-track acceleration. The method consistently converges within 10 iterations and achieves 24 h position predictions with root mean square errors of less than 3 km under realistic noise conditions. Additional validation using a higher-fidelity model that explicitly accounts for atmospheric drag demonstrates improved accuracy and robustness. The proposed method can provide accurate orbit knowledge for space situational awareness associated with continuously maneuvering Starlink satellites.