Collaborative Research: CubeSat: Ionosphere Thermosphere Scanning Photometer for Ion-Neutral Studies (IT-SPINS)

合作研究：CubeSat：用于离子中性研究的电离层热层扫描光度计 (IT-SPINS)

• 批准号: 1445467
• 负责人: Richard Doe
• 金额: $ 27.94万
• 依托单位: SRI International
• 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: 2015-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1445467&HistoricalAwards=false
• 关键词: Collaborative; Research; CubeSat; Ionosphere; Thermosphere

This project is to design, develop, construct, operate and analyze the results of a spacecraft CubeSat mission named "Ionospheric-Thermospheric Scanning Photometer for Ion-Neutral Studies" (IT-SPINS). The ionosphere affects modern technologies such as civilian and military communications and navigation and surveillance systems. Reliable communication and navigation, therefore, often requires correction of the signals for effects imposed by the ionosphere. To do that the properties of the ionosphere, such as its variability with respect to magnetospheric disturbance, time of day, season of the year, and solar cycle variability must be well understood and modeled. The fundamental measurements of IT-SPINS are high-sensitivity line-of-sight observations of Ultra Violet nightglow radiance produced by the recombination of Oxygen ions with electrons in the upper ionosphere. IT-SPINS will rotate at two rotations per minute about the orbit normal and will acquire 60 radiance measurements per revolution. Observations from several rotations will then be combined in a tomographic inversion algorithm to produce two-dimensional altitude/in-track images of the emissions. In this way, IT-SPINS will provide the first-ever set of unambiguous, geographically-extended measurements of the Oxygen ion distributions within the nightside ionosphere. Specifically, IT-SPINS will provide crucial information on the ion gradient structures in the, so-called, Topside Transition Region, from approximately 500km to 1000km altitude, where a transition takes place in the plasma conditions from being dominated by Oxygen ions to being dominated by Hydrogen ions. Prior studies of the TTR have primarily used large incoherent scatter radars at only a few locations around the World. Consequently, a thorough climatological study of the TTR's dependence on latitude, local time, and solar and geomagnetic activity does not exist at present. Lacking fundamental understanding of the variability of the TTR and the detailed morphology of Oxygen ion distributions throughout the TTR is a critical limitation currently in our ability to accurately model and predict ionospheric variability. Beyond fundamental space weather objectives, the IT-SPINS project places a significant priority on experimental learning in Science, Technology, Engineering and Mathematics (STEM) education at the university undergraduate level. Undergraduate students will participate in responsible roles on all aspects of the project. This provides the students with rare and valuable opportunities to learn and practice project management; systems engineering; engineering design, development and testing; and flight operations and data analysis skills through first-hand, project-based learning while being mentored by faculty and professional staff. In addition, through affiliation with the statewide Montana Space Grant Consortium(MSGC), the project will engage traditionally disadvantaged students at MSGC affiliated Tribal Colleges with IT-SPINS operational activities during the orbital phase. IT-SPINS can achieve compelling science results over a wide range of available orbit inclinations (40 degrees) and altitudes (500-700 km). This altitude range puts us at optimal viewing of the TTR above, and plasma structures below the satellite while ensuring a 25-year de-orbit criteria. The following primary and secondary science objectives and derived science questions are designed so that a subset of them can be addressed by IT-SPINS regardless of the satellite orbit it will be given. The primary science objective for the mission is to study the variability of the TTR and O+ altitude profiles. The following three questions will be addressed: 1) How does the altitude and thickness of the boundary between O+ dominated ionospheric physics and H+, He+ dominated plasmasphere physics vary as a function of magnetic L-shell, magnetic longitude, local time and geomagnetic activity? 2) How well do Geospace numerical models predict the observed variability of the TTR and O+ altitude profiles? 3) What is the importance of the charge exchange between O+ and neutral hydrogen to the TTR? Imaging the mesoscale structuring of equatorial plasma bubbles and polar cap patches constitutes a secondary science objective for the mission. The equatorial part of the secondary science objective can be addressed by both mid- and high inclination orbits, whereas the polar patch part can only be addressed for high inclination orbits(~70 degrees or higher).

该项目是设计、开发、建造、运行和分析名为“用于离子-中性研究的电离层-热层扫描光度计”(IT-SPINS)的立方体卫星航天器任务的结果。电离层影响民用和军用通信以及导航和监视系统等现代技术。因此，可靠的通信和导航往往需要对电离层施加的影响的信号进行校正。为此，必须很好地了解和模拟电离层的属性，例如其相对于磁层扰动的可变性、一天中的时间、一年中的季节以及太阳周期的可变性。IT自旋的基本测量是对氧离子与电离层上层电子重新组合产生的紫外线夜辉辐射的高灵敏度视线观测。它的自转将以每分钟两圈的速度绕轨道法线旋转，每转一圈将获得60个辐射测量值。然后，来自几个自转的观测结果将在层析反演算法中组合起来，以产生排放的二维高度/在轨图像。通过这种方式，IT-Spins将提供有史以来第一套明确的、地理上扩展的夜间电离层内氧离子分布的测量结果。具体地说，IT自旋将提供关于所谓的上方过渡区离子梯度结构的关键信息，从大约500公里高度到1000公里高度，在那里等离子体条件下发生从氧离子主导到氢离子主导的转变。以前对TTR的研究主要是在世界各地的少数几个地点使用大型非相干散射雷达。因此，目前还不存在对TTR对纬度、当地时间以及太阳和地磁活动的依赖的彻底气候学研究。缺乏对TTR的可变性和整个TTR中氧离子分布的详细形态的基本了解，是目前我们准确模拟和预测电离层可变性的能力的一个严重限制。除了基本的空间气象目标外，IT-SPINS项目还将重点放在大学本科生的科学、技术、工程和数学(STEM)教育方面的实验学习上。本科生将参与该项目的所有方面的负责角色。这为学生提供了难得的宝贵机会，在教师和专业人员的指导下，通过基于项目的第一手学习，学习和实践项目管理；系统工程；工程设计、开发和测试；以及飞行操作和数据分析技能。此外，通过与全州范围的蒙大拿州空间赠款联盟(MSGC)建立联系，该项目将在轨道阶段吸引MSGC附属部落学院传统上处于不利地位的学生参与IT自旋操作活动。它的自旋可以在大范围的可用轨道倾斜度(40度)和高度(500-700公里)上取得令人信服的科学结果。在这个高度范围内，我们可以看到上方的TTR和卫星下方的等离子体结构的最佳视角，同时确保25年的脱轨标准。以下主要和次要科学目标和衍生科学问题的设计是为了使其中的一部分可以通过IT自旋来解决，而不管它将被给定的卫星轨道。这次飞行任务的主要科学目标是研究TTR和O+高度剖面的可变性。将讨论以下三个问题：1)以O+为主的电离层物理和以H+、He+为主的等离子体层物理之间的边界的高度和厚度是如何作为磁L壳层、磁经度、当地时间和地磁活动的函数变化的？2)地球空间数值模式对TTR和O+高度剖面的观测变化的预测有多好？3)O+和中性氢之间的电荷交换对TTR值的重要性是什么？对赤道等离子体气泡和极帽补丁的中尺度结构进行成像是此次飞行任务的次要科学目标。第二科学目标的赤道部分可以通过中倾角轨道和高倾角轨道处理，而极地补丁部分只能针对高倾角轨道(~70度或更高)。