A dynamical model is developed in the body-fixed frame of Phobos, in which the high-precision gravity field and exact physical libration of Phobos, the gravity of Mars with J₂, and the gravity perturbations of the Sun, Jupiter, and Earth are considered. The JPL development ephemeris are applied to calculate the positions of celestial bodies. Phobos is considered as a homogeneous polyhedron with 16 037 vertices to characterize its irregular shape and the corresponding gravity field. The physical libration of Phobos is incorporated into its rotational motion by using the results in ‘Report of the IAU WGCCRE’. With the proposed model, equivalent gravity and slope on Phobos surface are calculated and analysed. The liftoff velocity is also computed and presented. Besides, the orbital environment is also investigated. Instantaneous equilibrium points in the Mars–Phobos system are computed and demonstrated, and the acceleration of a particle in the vicinity of Phobos is analysed to find out the main influencing factor in different regions. Quasi-satellite orbits and libration point orbits, which were determined in the circular restricted three-body problem model, are simulated in different dynamical models. The results applying the newly developed high-fidelity dynamical model have shown significant differences with respect to existing models, suggesting that dynamical models with higher accuracy are needed for close-range orbital activities.

中文翻译：

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考虑星历和物理解放作用的火卫一动力学环境分析

在火卫一的人体固定框架中建立了一个动力学模型，其中高精度火场和火卫一的精确物理解脱，火星的J ₂引力，并考虑了太阳，木星和地球的重力扰动。JPL发展星历用于计算天体的位置。Phobos被认为是具有16037个顶点的均质多面体，以表征其不规则形状和相应的重力场。通过使用“ IAU WGCCRE的报告”中的结果，火卫一的物理释放被纳入其旋转运动中。利用所提出的模型，计算并分析了Phobos表面上的等效重力和斜率。升空速度也被计算并给出。此外，还研究了轨道环境。计算并证明了Mars-Phobos系统中的瞬时平衡点，分析了火卫一附近粒子的加速度，找出了不同区域的主要影响因素。在不同的动力学模型中模拟了在圆形约束三体问题模型中确定的准卫星轨道和解放点轨道。应用新开发的高保真动力学模型的结果显示出与现有模型的显着差异，这表明近距离轨道活动需要精度更高的动力学模型。