This work proposes a continuum-based approach for the propagation of uncertainties in the initial conditions and parameters for the analysis and prediction of spacecraft re-entries. Using the continuity equation together with the re-entry dynamics, the joint probability distribution of the uncertainties is propagated in time for specific sampled points. At each time instant, the joint probability distribution function is then reconstructed from the scattered data using a gradient-enhanced linear interpolation based on a simplicial representation of the state space. Uncertainties in the initial conditions at re-entry and in the ballistic coefficient for three representative test cases are considered: a three-state and a six-state steep Earth re-entry and a six-state unguided lifting entry at Mars. The paper shows the comparison of the proposed method with Monte Carlo based techniques in terms of quality of the obtained marginal distributions and runtime as a function of the number of samples used.

中文翻译：

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使用连续性方程和简单插值的再输入不确定性的传播和重构

这项工作提出了一种基于连续体的方法，用于在初始条件和参数的不确定性传播中进行航天器再入的分析和预测。使用连续性方程式和重入动力学，不确定性的联合概率分布会针对特定采样点及时传播。然后在每个时刻，基于状态空间的简单表示，使用梯度增强的线性插值方法从散乱数据中重建联合概率分布函数。考虑了三个代表性测试用例的再入初始条件和弹道系数的不确定性：火星的三态和六态陡峭地球再入和六态无引导举升。