小行星重力场全球及局部球谐系数计算与仿真

摘要

To get high precision global sphere harmonic coefficients, selection strategy of test points and the partition method of polyhedron model are summarized. Quantitative analysis shows the superiority of uniform distribution test points and the polyhedron division method with equal size facets. Then, the concept of local sphere harmonic coefficient is proposed. After choosing the test points located in the detector’ s major operation area, a new performance index to measure the effectiveness of local coefficients is constructed. The proposed new concept is shown to be able to effectively improve the gravity field modeling accuracy for certain area and overcome the defect of traditional sphere harmonic function method that can not be used in brillouin ball, resulting enlarged application range. Finally, the global and local sphere harmonic coefficients of Eros433 are calculated, which validates the effectiveness and availability of the method presented in this paper.%为得到高精度的全球球谐系数，总结提出了检验点选取方式和多面体模型划分策略，定量分析表明了均匀取点和等面积划分法的优越性。提出了局部球谐系数概念，集中在小行星探测器任务规划中的主要活动区域选取检验点进行计算，通过构建一种新的性能指标说明了局部球谐系数的有效性。局部球谐系数可有效提高特定区域的重力场建模精度，克服传统意义球谐函数法无法在布里渊球域内使用的缺陷，显著提升了球谐函数法的应用范围。最后，以小行星Eros433为实际算例，计算了全球及局部球谐系数，说明了本文方法的有效性。