CAREER: Self-Consistent Density Estimates from Accelerometers for Improved Understanding, Modeling, and Forecasting of Upper Atmosphere Variability

该CAREER奖支持西弗吉尼亚大学（UWV）的一项研究，旨在通过开发有源卫星和空间碎片的轨道衰减预测能力来加强对高层大气变化的理解，建模和预测。在过去的二十年里，高精度、高分辨率的加速计质量密度估计一直是高层大气密度科学研究和建模工作的主力。然而，目前有限的知识的气体-表面相互作用（GSI）的密度测定的基础上测得的大气阻力的结果，模型的结果是不自洽的。迭代过程可以解决这种不一致性，但是这种要求使已经复杂的过程变得复杂，并且在计算上具有挑战性。该合同旨在通过开发一个全状态（成分、温度、风）降阶模型和直接吸收阻力加速度测量值来同时估计全球静止轨道影响和热层参数，从而解决这一不一致问题。利用这些估计参数，所开发的GSI模型将用于全面调查中性密度对地磁暴的时空响应，并将成为推进科学和业务的宝贵资源。准确的轨道预测可增强决策的信心，加强人类在空间的安全，并促进长期保护空间环境。该职业奖将通过针对农村、第一代、阿巴拉契亚学生和K-12教师的举措支持西澳大学的空间科学教育。该奖项将支持在研究和教育推广活动方面培训两名研究生和多名本科生。将在机械和航空工程课程中开设一门名为“空间物理学和空间系统”的新课程，该奖项所支助的研究将实现为基于物理学的高层大气密度模型开发只读存储器，扩大其在科学和业务中的作用。只读存储器将使利用卫星上的加速度测量值得出密度估计值的过程变得更加自洽，并将为中性密度对地磁暴的时空响应提供新的见解。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This CAREER award supports a study at the University of West Virginia (UWV) designed to enhance the understanding, modeling, and forecasting of upper atmosphere variability by developing an orbital decay prediction capability for active satellites and space debris. High precision, high resolution accelerometer-derived mass density estimates have been the workhorse of scientific investigations and modeling efforts for the upper atmosphere density over the past two decades. However, the current limited knowledge of Gas-Surface Interaction (GSI) used in the density determination based upon measured atmospheric drag has the consequence that model results are not self-consistent. An iterative process can address this inconsistency, but this requirement complicates an already complex process and can be computationally challenging. The award is aimed at resolving this inconsistency through the development of a full-state (composition, temperature, winds) reduced order model (ROM) and directly assimilating drag acceleration measurements to simultaneously estimate the GSI effects and thermosphere parameters. Using these estimated parameters, the developed GSI model would be used to comprehensively investigate the spatial and temporal response of neutral density to geomagnetic storms and would serve as an invaluable resource for advancing science and operations. Accurate orbit predictions can provide more confidence in decision-making, enhance the safety of humans in space and facilitate long-term preservation of the space environment. This CAREER award would support the UWA space science education through initiatives targeted at rural, first-generation, Appalachian students and K-12 teachers. The award would support the training of two graduate and multiple undergraduate students in both research and educational outreach activities. A new course called “Space Physics and Space Systems” would be introduced into the mechanical and aeronautical engineering curriculum.The research supported by this award would achieve the development of a ROM for physics-based upper atmosphere density models, expanding its role in science and operations. The ROM would make the process of deriving densities estimates using measurements of acceleration on-board satellites become more self-consistent and would provide new insights into the temporal and spatial response of the neutral density to geomagnetic storms. It would also help operators advance accurate modeling of satellite drag for orbit prediction, collision avoidance and space environment sustainability.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.