Collaborative Research: RAPID--To Conduct Ionospheric Irregularity and Scintillation Experiments Using the Radio Aurora Explorer II

这是利用RAX II航天器以及地面非相干散射雷达和加热设施进行初步协调一致的相干散射和反辐射实验的短期努力。无线电极光探索者（RAX）卫星是第一个被选中和飞行的NSF立方体卫星使命。它于2010年11月发射，并与NSF的扑克牌平板非相干散射雷达（PFISR）合作成功地进行了两次雷达实验。不久之后，太阳能系统退化，使命提前终止。美国航天局最近于2011年10月发射的备用飞行航天器（RAX II）为继续RAX使命提供了机会。 RAX使命是一个地对空双基地雷达遥感实验，旨在测量强极光扰动期间发生的米级电离层湍流。五个分布在全球的超高频非相干散射雷达设施将用于照射自然/人工电离层场向不规则体。RAX UHF雷达接收机测量沿着卫星轨道多点的相干后向散射，由此可以量化平行于地磁场线的等离子体波能量分布。 RAX II实验将针对中高纬度地区自然发生的和人为产生的电离层不规则现象进行。RAX I计划解决自然电离层的不规则性; RAX II的实验范围扩大到解决新的高频加热器产生的影响。目标是捕获（1）来自自然和人工电离层不规则体的相干散射，以及（2）通过自然和人工产生的不规则体的UHF信号的幅度和相位失真。 电离层不规则性后向散射实验将与兆瓦级窄波束超高频非相干散射雷达协调进行，以提供电离层电场、电流和等离子体密度梯度各种条件下电离层不规则性（高度在80-400公里之间）的高空间和时间分辨率测绘。 除了研究自然发生的等离子体湍流的特性外，我们还将进行实验，以测量电离层E和F区域的高功率HF加热所产生的人工电离层不规则性。目前，有两个加热器设施可用于此目的：HAARP和SPARK。模块化超高频非相干散射雷达（MUIR）和EISCAT斯瓦尔巴特群岛雷达（ESR）将分别与RAX II一起工作，用于人工产生的等离子体湍流的诊断。将使用RAX超高频有效载荷接收器的原始数据采集模式测量超高频信号的电离层闪烁，更好地了解电离层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可能对通过卫星、高频和甚高频无线电进行的通信产生不利影响，并对导航、跟踪和定位产生不利影响。该项目将促进教育和学习，因为密歇根大学的研究生将进行大部分卫星操作和数据处理。

This is a short term effort to conduct initial orchestrated coherent scatter and scintillations experiments utilizing the RAX II spacecraft together with ground based incoherent scatter radar and heating facilities. The Radio Aurora Explorer (RAX) satellite was the first NSF Cubesat mission to be selected and flown. It was launched in November 2010 and successfully executed two radar experiments in coordination with NSF's Poker Flat Incoherent Scatter Radar (PFISR). Shortly after, the solar power system degraded, and the mission prematurely terminated. The recent NASA launch of the backup flight spacecraft (RAX II) in October 2011 offers the opportunity to continue the RAX mission. The additional experiments that this opportunity enables are the subject of this RAPID projectThe RAX mission is a ground-to-space bi-static radar remote sensing experiment designed to measure meter-scale ionospheric turbulence that occurs during strong auroral disturbances. Five globally distributed UHF Incoherent Scatter Radar facilities will be used to illuminate natural/artificial ionospheric field-aligned irregularities (FAI). The RAX UHF radar receiver measures coherent backscatter at multiple points along the satellite track, from which on can quantify the plasma wave energy distribution parallel to the geomagnetic field lines. RAX II experiments will be conducted for both naturally occurring and artificially generated ionospheric irregularities in mid to high latitudes. RAX I was planned to address natural ionospheric irregularities; with RAX II, the experimental scope is expanded to address new HF heater generated effects. The goals are to capture (1) coherent scatter from natural and artificial ionospheric irregularities, and (2) the amplitude and phase distortions of UHF signals passing through naturally and artificially generated irregularities. Ionospheric irregularity backscatter experiments will be coordinated with megawatt-class narrow-beam UHF incoherent scatter radars to provide high spatial and temporal resolution mapping of ionospheric irregularities (between the altitudes of 80-400 km) for a wide range of conditions for the ionospheric electric field, currents, and plasma density gradients. In addition to studying the properties of naturally occurring plasma turbulence, we will run experiments to measure artificial ionospheric irregularities generated by high-power HF heating of the ionospheric E and F regions. Currently, two heater facilities are available for this purpose: HAARP and SPEAR. The Modular UHF Incoherent Scatter Radar (MUIR) and the EISCAT Svalbard Radar (ESR), respectively, will be the ISRs operating in conjunction with RAX II for diagnostics of the artificially generated plasma turbulence. Ionospheric scintillation of UHF signals will be measured using the raw data acquisition mode of the RAX UHF payload receiver.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 will promote education and learning in that graduate undergraduate students from University of Michigan will perform the majority of the satellite operations and data handling.