Analysis and Modeling of the Data from CubeSat: Colorado Student Space Weather Experiment (CSSWE)

CubeSat 数据的分析和建模：科罗拉多州学生空间天气实验 (CSSWE)

• 批准号: 1443749
• 负责人: Xinlin Li
• 金额: $ 34.5万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1443749&HistoricalAwards=false
• 关键词: Analysis; Modeling; Data; CubeSat; Colorado

The electron radiation environment around Earth is a major hazard to spaceflight assets. Understanding it, ideally to the point of predictive modeling of its response to changing solar wind driving conditions, is a central goal of magnetospheric physics. The condition in the radiation belts at any given time is the result of a delicate balance between energization and loss processes operating on the particles in the near-Earth environment. Neither of these is well understood at present. This project will use new measurements from a NSF-funded CubeSat mission that was recently carried out together with numerical modeling to determine the energetic electron loss rate. Only when the loss rate is accurately determined will it be possible to fully model the radiation belt dynamics. The Colorado Student Space Weather Experiment (CSSWE) is a tiny, so-called CubeSat, satellite mission funded by NSF and launched into a high inclination, low-altitude orbit as a secondary payload under NASA?s Educational Launch of Nanosatellites (ELaNa) program in September 2012. The entire CSSWE system, including its ground station, was designed, built, calibrated, tested, delivered, and operated by students, with mentoring and help provided by faculty and professional engineers at the Laboratory for Atmospheric and Space Physics at University of Colorado. The satellite project far exceeded it?s expected life-time and has collected more than 12 months worth of high quality data on energetic electrons and protons in Low-Earth-Orbit. The advanced data analysis to be done under this award will continue the exploitation of this unique dataset and, in turn, will help to maximize the scientific return on investment of this already highly successful CubeSat project. For the most part, the scientific investigation is designed for and will be carried out by graduate students under the supervision of the PI and collaborators. To date, the precipitation loss rate of the outer radiation belt electrons has not been quantified and resolved. The electron loss rates in current published papers are erratic and diverge by an order of magnitude. The goal of this study is to quantify the precipitation losses and their dependence on longitude, L, and MLT directly from the data with advanced modeling, thus providing a quantitative answer to the research community on this important issue. Specifically, this effort will analyze over a year's worth of CSSWE data in conjunction with the NASA Van Allen Probes to determine the loss rates into the ionosphere during periods of gradual decay, during episodes of fast loss and during episodes of large gain. Analyzing CSSWE data during periods of gradual loss will determine how much additional energization occurs during such periods to maintain the radiation belts; analyzing the data during periods of fast loss will determine how much of the loss occurs by scattering into the ionosphere versus loss due to outward radial diffusion; analyzing the loss during periods of large gains will determine how much additional energization is needed to produce the observed gains in electron flux. The impact of such precipitation loss to the overall dynamics of radiation belt electrons will then be assessed by comparing the measurements of CSSWE and the corresponding modeling results with measurements from the Van Allen Probes at the same times and locations.

地球周围的电子辐射环境是航天资产的主要危害。 理解它，最好是对其对不断变化的太阳风驱动条件的响应进行预测建模，是磁层物理学的中心目标。 任何给定时间辐射带的状况都是近地环境中粒子的供能和损耗过程之间微妙平衡的结果。 目前这些都还没有被很好地理解。 该项目将使用 NSF 资助的 CubeSat 任务的新测量结果，该任务最近与数值建模一起进行，以确定高能电子损失率。 只有准确确定损失率，才有可能对辐射带动力学进行全面建模。科罗拉多学生空间天气实验 (CSSWE) 是一个小型的、所谓的 CubeSat 卫星任务，由 NSF 资助，并作为 NASA 纳米卫星教育发射 (ELaNa) 计划的辅助有效载荷发射到高倾角、低空轨道2012 年 9 月。整个 CSSWE 系统，包括地面站，由学生设计、建造、校准、测试、交付和操作，并得到实验室教师和专业工程师的指导和帮助科罗拉多大学大气与空间物理学专业。 该卫星项目远远超出了其预期寿​​命，并收集了超过 12 个月的有关近地轨道高能电子和质子的高质量数据。 该奖项下进行的高级数据分析将继续利用这一独特的数据集，进而有助于最大限度地提高这一已经非常成功的 CubeSat 项目的科学投资回报。 在很大程度上，科学研究是为研究生设计的，并将由研究生在 PI 和合作者的监督下进行。迄今为止，外辐射带电子降水损失率尚未量化和解决。当前发表的论文中的电子损失率不稳定并且相差一个数量级。本研究的目标是通过高级建模直接从数据中量化降水损失及其对经度、L 和 MLT 的依赖性，从而为研究界提供关于这一重要问题的定量答案。 具体来说，这项工作将与 NASA 范艾伦探测器一起分析一年多的 CSSWE 数据，以确定电离层在逐渐衰变期间、快速损失期间和大量增益期间的损失率。分析逐渐损失期间的CSSWE数据将确定在此期间发生多少额外的能量来维持辐射带；分析快速损失期间的数据将确定有多少损失是由于散射到电离层而发生的，还是由于向外径向扩散造成的损失；分析大增益期间的损耗将确定需要多少额外的能量才能产生观察到的电子通量增益。 然后，通过将 CSSWE 的测量值和相应的建模结果与范艾伦探测器在同一时间和地点的测量值进行比较，可以评估这种降水损失对辐射带电子整体动力学的影响。