On 19th October 2016 Schiaparelli module of the ExoMars 2016 mission flew through the Mars atmosphere. After successful entry and descent under parachute, the module failed the last part of the descent and crashed on the Mars surface. Nevertheless the data transmitted in real-time by Schiaparelli during the entry and descent, together with the entry state vector as initial condition, have been used to reconstruct both the trajectory and the profiles of atmospheric density, pressure and temperature along the traversed path.The available data-set is only a small sub-set of the whole data acquired by Schiaparelli, with a limited data rate (8 kbps) and a large gap during the entry because of the plasma blackout on the communications.This paper presents the work done by the AMELIA (Atmospheric Mars Entry and Landing Investigations and Analysis) team in the exploitation of the available inertial and radar data. First a reference trajectory is derived by direct integration of the inertial measurements and a strategy to overcome the entry data gap is proposed. First-order covariance analysis is used to estimate the uncertainties on all the derived parameters. Then a refined trajectory is computed incorporating the measurements provided by the on-board radar altimeter.The derived trajectory is consistent with the events reported in the telemetry and also with the impact point identified on the high-resolution images of the landing site.Finally, atmospheric profiles are computed tacking into account the aerodynamic properties of the module. Derived profiles result in good agreement with both atmospheric models and available remote sensing observations.

中文翻译：

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ExoMars 2016 Schiaparelli 模块轨迹和大气剖面重建

2016 年 10 月 19 日，ExoMars 2016 任务的 Schiaparelli 模块飞过火星大气层。在降落伞下成功进入和下降后，该模块在下降的最后部分失败并坠毁在火星表面。然而，Schiaparelli 在进入和下降期间实时传输的数据，连同作为初始条件的进入状态向量，已被用于重建轨迹以及沿穿越路径的大气密度、压力和温度的轮廓。可用数据集只是 Schiaparelli 获取的整个数据的一小部分，数据速率有限（8 kbps），并且由于通信中的等离子中断而在输入期间存在较大间隙。本文介绍了 AMELIA（大气火星进入和着陆调查与分析）团队在利用可用惯性和雷达数据方面所做的工作。首先通过惯性测量的直接积分导出参考轨迹，并提出了克服输入数据差距的策略。一阶协方差分析用于估计所有导出参数的不确定性。然后结合机载雷达高度计提供的测量结果计算出一条细化的轨迹。得出的轨迹与遥测中报告的事件以及着陆点高分辨率图像上识别的撞击点一致。最后，大气剖面的计算考虑到模块的空气动力学特性。