Extended Kalman Filter
Author: Tianjiang Shuo
Website: https://cislunarspace.cn
Definition
An estimation algorithm that linearizes the nonlinear state and measurement equations via first-order Taylor expansion around the current estimate, then applies standard Kalman filter recursive formulas. The paper uses EKF for libration point orbit celestial navigation: the state equation is the three-body problem dynamics, the measurement equation is the nonlinear relation between starlight angle and position, and a first-order linearized state transition matrix suffices for accuracy. Simulation results show EKF in the barycentric rotating frame converges position error to approximately 7.5 km (2 navigation stars, 10 s sampling period).
Application Value
The extended Kalman filter handles nonlinear problems through linearization, widely used in libration point orbit celestial navigation, converging to high accuracy.
Related Concepts
- Geometric Dilution of Precision
- Very Long Baseline Interferometry
- Deep Space Network
References
- 赵书阁 等 - 2013 - 日地系统L2点Halo轨道自主天文导航及精度分析
- Colagrossi 等 - 2021
- Pesce 等 - 2023 - Modern spacecraft guidance, navigation, and control
