Collaborative Research: CubeSat-based Ground-to-Space Bistatic Radar Experiment--Radio Aurora Explorer

该项目是SRI国际的空间科学首席研究员（PI）和密歇根大学的工程PI之间的合作。这个为期三年的跨学科团队努力的目标是建造和操作一个名为CubeSat的小型航天器，该航天器携带超高频雷达接收器有效载荷。这颗卫星的发射将作为国防部计划于2009年12月发射的次要卫星。该卫星将与地面的AMISR非相干散射雷达协同工作，从高纬度电离层的场对准不规则中调查射电极光。射电极光探测器（RAE）任务的主要科学目标是了解导致极低层（80-300公里）电离层电子密度场向不规则（FAI）的等离子体不稳定性的微观物理学。RAE任务是专门设计用于远程测量，具有极高的角分辨率（~0.5度），~1 m尺度FAI的波谱作为海拔的函数，特别是测量不规则的磁场对准。由于高纬度地区的磁场几何形状，这种双静态（地面雷达到卫星）配置是执行这些测量的唯一方法，在这种配置中，狭窄的雷达波束从FAI散射出来，然后由CubeSat接收器观察。更好地了解电离层的不规则性及其在电离层动力学中的作用是一个重要的空间气象研究目标，因为电离层中的等离子体结构会对卫星、高频和甚高频无线电的通信产生不利影响，也会对导航、跟踪和定位产生不利影响。这个项目有很强的教育成分；它依赖于广泛的本科生和研究生参与任务的各个方面。立方体卫星任务中涉及的新技术在很大程度上未经证实，这使得该项目本身就存在重大风险。然而，另一方面，该项目不仅在其本身的研究领域，而且在空间科学和大气研究以及航空航天工程和教育等更大领域具有巨大的变革潜力。

This project is a collaboration between a space science Principal Investigator (PI) at SRI International and an engineering PI at University of Michigan. The objective of this three-year cross-disciplinary team effort is to build and operate a tiny, so-called CubeSat, spacecraft carrying a UHF radar receiver payload. Launch of the satellite will be as a secondary on a Department of Defense launch scheduled for December 2009. The satellite will be operated in coordination with the AMISR incoherent scatter radar from the ground to investigate the radio aurora from field-aligned irregularities in the high-latitude ionosphere. The primary scientific objective of the Radio Aurora Explorer (RAE) mission is to understand the microphysics of plasma instabilities that lead to field-aligned irregularities (FAI) of electron density in the polar lower (80-300 km) ionosphere. The RAE mission is specifically designed to remotely measure, with extremely high angular resolution (~0.5 degree), the wave spectrum of ~1 m scale FAI as a function of altitude, in particular measuring the magnetic field alignment of the irregularities. Due to the magnetic field geometry at high latitudes this bi-static (ground radar to satellite) configuration, in which a narrow radar beam is scattered off the FAI and then observed by the CubeSat receiver, is the only way to perform these measurements. Better understanding of ionospheric irregularities and their role in ionospheric dynamics is an important space weather research objective because plasma structures in the ionosphere can have an adverse effect on communications via satellite, HF and VHF radio and as well as an adverse effect on navigation, tracking, and positioning. The project has a very strong educational component; it relies on extensive undergraduate and graduate student involvement through all aspects of the mission. The new, largely unproven technology involved in cubesat missions, inherently makes the project associated with significant risks. On the other hand, however, the project has tremendous potential to be transformational not only within its own research area but also for the larger field of space science and atmospheric research as well as within aerospace engineering and education.