基于频谱特征的低轨卫星经验力建模与非保守力模型精化研究

摄动力模型的精度是制约低轨卫星动力学定轨的重要因素，直接决定了轨道坐标的精度和系统误差的量级，动力学模型精化是当前国内外研究的瓶颈问题。本项目扩展传统辐射压中单一辐射源为可见光和红外光，精化地球反照辐射、太阳光压等非保守力模型；利用长期在轨数据研究低轨卫星未模型化的摄动加速度频谱特征，研究基于频谱特征的经验力建模方法、经验力参数模型的最优配置准则及其模型适用性；以此为基础，研究基于经验力建模和非保守力精化的低轨卫星精密定轨，结合星载GNSS接收机天线相位中心在轨标定和非差模糊度固定技术，开展国产卫星（HY2、ZY3等）卫星精密定轨重处理研究；通过激光检核、轨道重叠比较等手段评估非保守力模型精化和经验力建模后的定轨精度和系统误差。期望通过本项目的研究，完善星载GNSS动力学定轨理论方法，实现对国产低轨卫星的mm级定轨目标，进一步提升我国低轨对地观测卫星定轨精度和应用水平。

The accuracy of the dynamical model is an important factor in satellite precise orbit determination(pod) which directly determines the precision of the orbit coordinates and the magnitude of the system error. The refinement and modeling of the dynamical model is the difficulty in the satellite geodesy at home and abroad. First of all, the project aim at refining the non-conservative force models of satellite, like earth's albedo pressure, solar radiation and so on, which lays the foundation for the extraction of the unmodeled satellite’s perturbation acceleration. Long-term observation data is used to study the spectrum characteristics of the unmodeled acceleration of LEO satellite, which will help study the empirical force modeling based on the spectrum characteristics and discover the optimal allocation strategy of the empirical force model parameter and its limitation. On above basis, the reprocessing strategy is applied in precision orbit determination for domestic satellite (HY2, ZY3 etc.)The improvement of pod solution and system error magnitude, while the refined non-conservative force model and empirical force modeling are applied in pod computation, are evaluated by means of satellite laser range(SLR) validation and orbital overlap comparison. This project aim at realizing the target of mm level for domestic LEO satellites pod and further improve application level of Chines remote sensing LEO satellites.