MRI: Development of An Airborne Infrared Spectrometer (AIR-Spec) for Coronal Emission Line Observation

MRI：开发用于日冕发射线观测的机载红外光谱仪 (AIR-Spec)

• 批准号: 1531549
• 负责人: Edward DeLuca
• 金额: $ 120.06万
• 依托单位: Smithsonian Institution Astrophysical Observatory
• 依托单位国家: 美国
• 项目类别: Standard 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=1531549&HistoricalAwards=false
• 关键词: MRI; Development; Airborne; Infrared; Spectrometer

Total solar eclipses offer unique opportunities for scientific explorations and discoveries, and also for people of all walks of life and ages to witness one of Nature's most fascinating displays of beauty. On August 21, 2017, a rare total solar eclipse event will occur that will traverse the continental United States, starting in Oregon and ending in South Carolina. The previous such occasion was on 29 July 1878. The purpose of this major research instrumentation project is to design, build, test, and fly a highly advanced imaging spectrometer to make measurements during this eclipse, for the first time, of the solar corona in the infrared spectrum. This opens a new wavelength window for observation of the solar corona that has exiting potential for advancing our understanding of this hard-to-observe region. The Airborne Infra-Red Spectrometer (AIR-Spec) instrument will include a novel image stabilization system to allow it to be deployed on NSF's Gulfstream V aircraft operated by the National Center for Atmospheric Research (NCAR). Flying at an altitude above 49,000 feet makes it possible to get measurements without disturbances from local weather and avoiding most of the absorbing water vapor in the atmosphere that poses a challenge for observations at the ground. The completion of this program will see the delivery to NCAR of a stable commissioned instrument that is certified and available for other scientist to fly on the GV for future research missions. The GV can travel almost anywhere and re-flights at other future eclipses are an obvious possibility to pursue. The July 2, 2019, South Pacific eclipse will be the first chance for another eclipse flight. In addition, the stabilized high resolution observing capability can be used by other experiments for solar and atmospheric observations throughout the world.The project will be carried out in collaboration between the scientists and engineers at the Smithsonian Astrophysical Observatory (SAO) and NCAR's High Altitude Observatory (HAO), each contributing essential expertise and experience to ensure its successful completion. The project will directly contribute to training the next generation of instrumentation scientists while fostering diversity. A Harvard graduate student from the School of Engineering and Applied Sciences will be involved in all aspects of the project, including design, fabrication and test of the AIR-Spec instrument, as well as analysis of the observations, if scientific data are acquired during the eclipse. This will form the basis for her thesis and she will enjoy the benefits of mentoring from scientists and engineers at both SAO and HAO. In addition, the 2017 US solar eclipse is expected to generate a huge amount of interest amongst the general public and the project team will work closely with partners at the National Air and Space Museum, the Boston Museum of Science and the Eclipse Mega-Movie group at HAO on pre and post eclipse outreach events. The AIR-Spec instrumentation includes an image stabilization system, a feed telescope, a grating spectrometer and a slit-jaw imager. It will measure emission line intensity, FWHM, and Doppler shift a set of magnetically sensitive coronal emission lines at a range of coronal positions during the August 21, 2017 "Great American Eclipse". Although high resolution, high sensitivity coronal imaging spectroscopy has never been performed between 1.4 and 4um, this spectral region has great potential for coronal plasma diagnostics, for coronal hole spectroscopy, and as a path finder for observations of coronal magnetic fields. Infrared coronal emission lines are well suited for measuring magnetic field properties using the Zeeman and Hanle effects, but such measurements require high precision spectro-polarimetric instruments that cannot be designed until the candidate emission lines have been characterized. The 2017 eclipse provides a unique opportunity to survey these lines, and AIR-Spec observations can help provide guidance for future ground-based Infrared observations. The AIR-Spec commissioning flight during the 2017 eclipse will target three science goals: (1) Search for high frequency waves in multiple lines at multiple locations in the corona. These waves are candidates for heating and acceleration of the solar wind. (2) Identify large-scale flows in the corona, particularly in polar coronal holes. Three of the lines to be observed are expected to be strong in coronal hole plasmas because they are excited in part by scattered photospheric light. Line profile analysis will probe the origins of the fast and slow solar wind. (3) Complement ground based eclipse observations to provide detailed plasma diagnostics throughout the corona. AIR-Spec will measure IR emission of ions also observed in the visible, giving insight into plasma heating and acceleration at radial distances inaccessible with existing or planned spectrometers. On the technology side, the AIR-Spec stabilization system removes a significant obstacle to airborne observations. The system relies on inertial measurements to stabilize the platform to 1.4 arcsec RMS for the planned 0.3 sec exposure (1.7arcsec RMS per sec), allowing it to be used for a wide range of solar and atmospheric imaging experiments. Finally, for the future there is the possibility for AIR-Spec to be modified to add linear polarization optics for direct measurements of coronal magnetic field direction.

日全食为科学探索和发现提供了独特的机会，也为各行各业和各个年龄段的人们见证了大自然最迷人的美丽展示之一。 2017 年 8 月 21 日，将发生罕见的日全食事件，该事件将横贯美国大陆，从俄勒冈州开始，到南卡罗来纳州结束。上一次这样的场合是在 1878 年 7 月 29 日。这个重大研究仪器项目的​​目的是设计、建造、测试和飞行一台高度先进的成像光谱仪，以便在这次日食期间首次对日冕进行测量。红外光谱。 这为观测日冕打开了一个新的波长窗口，对于增进我们对这个难以观测区域的理解具有巨大的潜力。 机载红外光谱仪 (AIR-Spec) 仪器将包括一个新颖的图像稳定系统，使其能够部署在国家大气研究中心 (NCAR) 运营的 NSF 湾流 V 飞机上。 在 49,000 英尺以上的高度飞行，可以在不受当地天气干扰的情况下进行测量，并避免吸收大气中的大部分水蒸气，这对地面观测构成了挑战。 该计划完成后，将向 NCAR 交付一台稳定的委托仪器，该仪器经过认证，可供其他科学家乘坐 GV 执行未来的研究任务。 GV 几乎可以在任何地方旅行，并且在未来的其他日食中重新飞行是一个明显的可能性。 2019 年 7 月 2 日的南太平洋日食将是另一次日食飞行的第一次机会。 此外，稳定的高分辨率观测能力可用于世界各地的其他太阳和大气观测实验。该项目将由史密森天体物理观测站（SAO）和 NCAR 高空观测站的科学家和工程师合作开展(HAO)，每个人都贡献必要的专业知识和经验，以确保其成功完成。 该项目将直接有助于培训下一代仪器科学家，同时促进多样性。 哈佛大学工程与应用科学学院的一名研究生将参与该项目的各个方面，包括 AIR-Spec 仪器的设计、制造和测试，以及观测结果的分析（如果在该项目期间获得了科学数据）。蚀。这将构成她论文的基础，她将受益于 SAO 和 HAO 科学家和工程师的指导。 此外，2017 年美国日食预计将引起公众的极大兴趣，项目团队将与国家航空航天博物馆、波士顿科学博物馆和日食巨型电影小组的合作伙伴密切合作在 HAO 举办日食前后的外展活动。 AIR-Spec 仪器包括图像稳定系统、馈源望远镜、光栅光谱仪和狭缝成像仪。 它将测量 2017 年 8 月 21 日“美国大日食”期间一系列日冕位置处的发射线强度、半高宽和多普勒频移。尽管高分辨率、高灵敏度日冕成像光谱从未在 1.4 至 4um 之间进行过，但该光谱区域在日冕等离子体诊断、日冕洞光谱以及作为日冕磁场观测的探路者方面具有巨大潜力。红外日冕发射线非常适合利用塞曼效应和汉勒效应测量磁场特性，但这种测量需要高精度的分光偏振仪器，而只有在候选发射线被表征后才能设计这些仪器。 2017 年日食提供了一个独特的机会来调查这些线，而 AIR-Spec 观测可以帮助为未来的地面红外观测提供指导。 2017 年日食期间的 AIR-Spec 试飞将实现三个科学目标：(1) 在日冕多个位置的多条线路中搜索高频波。这些波是太阳风加热和加速的候选者。 (2) 识别日冕中的大规模流动，特别是极冕洞中的流动。预计观测到的三条线在冕洞等离子体中会很强，因为它们部分是由散射光球光激发的。线剖面分析将探测快太阳风和慢太阳风的起源。 (3) 补充地面日食观测，以提供整个日冕的详细等离子体诊断。 AIR-Spec 将测量在可见光中观察到的离子的红外发射，从而深入了解现有或计划的光谱仪无法到达的径向距离处的等离子体加热和加速。 在技​​术方面，AIR-Spec 稳定系统消除了机载观测的重大障碍。该系统依靠惯性测量将平台稳定在 1.4 角秒 RMS，以实现计划的 0.3 秒曝光（每秒 1.7 角秒 RMS），使其能够用于广泛的太阳和大气成像实验。 最后，未来 AIR-Spec 有可能进行修改，添加线性偏振光学器件以直接测量日冕磁场方向。