Spherical Harmonic Expansion
Author: Tianjiang Shuo
Website: https://cislunarspace.cn
Definition
A mathematical method that expands a celestial body's gravitational potential as a series of spherical harmonic functions. Each term in the expansion has a coefficient (e.g., Cnm, Snm) describing mass distribution characteristics at different spatial scales. Low-degree terms reflect overall shape (e.g., oblateness), while higher-degree terms capture local mass anomalies. Both the Earth gravity field model (JGM series) and lunar gravity field model (GL series) are constructed using this method. Higher expansion degrees yield more refined gravity field modeling at greater computational cost.
Application Value
Based on its definition, a mathematical method that expands a celestial body's gravitational potential as a series of spherical harmonic functions. each term in the expansion has a coefficient (e.g., cnm, snm) describing mass.
Related Concepts
- 轨道力学（Orbital Mechanics）
- 坐标系（Coordinate Frame）
- 积分（Integration）
References
- 刘磊 等 - 2008 - 多约束条件下的地月转移轨道设计