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险。了解它，最好是对它对不断变化的太阳风驱动条件的反应进行预测建模，是磁层物理学的一个中心目标。在任何给定的时间，辐射带中的情况都是在近地环境中对粒子进行操作的能量和损失过程之间微妙平衡的结果。目前，这两种情况都没有得到很好的理解。这个项目将使用美国国家科学基金会资助的立方体卫星任务的新测量结果，该任务最近与数值模拟一起执行，以确定高能电子损失率。只有准确地确定损失率，才有可能完全模拟辐射带的动态特性。科罗拉多州学生空间天气实验是一颗被称为立方体卫星的微小卫星任务，由美国国家科学基金会资助，作为美国国家航空航天局S教育发射纳米卫星计划的二次有效载荷于2012年9月发射到高倾角、低海拔轨道。整个CSSWE系统，包括它的地面站，都是由学生在科罗拉多大学大气和空间物理实验室的教师和专业工程师的指导和帮助下设计、建造、校准、测试、交付和操作的。这个卫星项目远远超出了它的预期寿命？S已经收集了12个多月的近地轨道高能电子和质子的高质量数据。根据该奖项将进行的高级数据分析将继续利用这一独特的数据集，反过来，将有助于最大化这个已经非常成功的CubeSat项目的科学投资回报。在很大程度上，科学调查是为研究生设计的，并将由研究生在PI和合作者的监督下进行。到目前为止，外辐射带电子的降水损失率还没有得到量化和解决。目前发表的论文中的电子损失率是不稳定的，相差一个数量级。本研究的目的是通过高级模型直接从数据中量化降水损失及其对经度、L和MLT的依赖关系，从而为研究界提供关于这一重要问题的定量答案。具体地说，这项工作将结合NASA范艾伦探测器分析CSSWE一年多的数据，以确定在逐渐衰变期间、在快速损失期间和在大幅增加期间进入电离层的损失率。分析CSSWE在逐渐损失期间的数据将确定在这种时间段内发生了多少额外能量来维持辐射带；分析快速损失期间的数据将确定有多少损失是由于散射进入电离层而发生的，还是由于向外径向扩散造成的损失；分析大增益期间的损失将确定需要多少额外能量才能产生观测到的电子通量增益。然后，通过将CSSWE的测量结果和相应的模拟结果与Van Allen探测器在相同时间和地点的测量结果进行比较，评估这种降水损失对辐射带电子整体动力学的影响。