Collaborative Research: A New 50 MHz Radar for Meteor and Aeronomical Science

研究人员将开发下一代流星雷达的原型，提高其获取中性风、温度和单个流星特性的能力。这些数据将用于确定更准确的全球流星通量特征及其对高层大气物理的影响。该雷达将在宾夕法尼亚州的一个地点运行，并将能够观测三种主要流星反射类型中的至少两种：1)常用的高光流星轨迹；2)最近发现的非镜面尾迹，是由等离子体不稳定和湍流产生的场对准不规则（FAI）引起的；3)流星头回波，这是一个以流星体速度移动的雷达目标。由于该系统可以在时间和空间上检测和解析至少两种机制，因此我们可以研究每种技术引入的观测偏差。这些偏差困扰着我们目前对高层大气中流星输入函数的表征，给大气参数的估计带来了不确定性。此外，头部回波和非镜面回波产生的详细无线电信号要比镜面回波复杂得多。该系统将采用最新的数字技术进行设计，以改进研究流星的可用数据，以及主温层和低层热层（MLT）大气区域的动力学和能量学。研究人员已经建立了强有力的国内和国际合作，这对于实现该计划的科学和教育目标至关重要。该研究将为本科生和研究生提供接触各种领域的机会，包括航空、流星科学、雷达系统的设计和建造、射频工程和软件雷达。

The investigators will develop a prototype of next generation meteor radars with improved ability for deriving neutral winds, temperatures and individual meteor properties. The data will be used to determine a more accurate characterization of the global meteor flux and its effect on upper atmospheric physics. The radar will be operated at a site in Pennsylvania and will be capable of observing at least two of three primary types of meteor reflection: 1) the commonly used specular meteor trails; 2) the recently understood non-specular trails, which result from plasma instability and turbulence generated field aligned irregularities (FAI); and 3) meteor head-echoes, which are a radar target moving at the speed of the meteoroid. Since the system can detect and resolve in time and space at least two mechanisms, we can study the observation biases introduced by each technique. These biases plague our current characterization of the meteor input function into the upper atmosphere, introducing uncertainties in the estimates of atmospheric parameters. Additionally, the detailed radio signature produced by both head echoes and non-specular trails are far more complex than specular echoes. The system will be designed using the latest digital technology, improving the available data for the study of both meteors, and the dynamics and energetics of themesosphere and lower thermosphere (MLT) atmospheric region. The investigators have built strong domestic and international collaborations that will be crucial in achieving the scientific and educational goals of the program. The research will provide undergraduate and graduate students exposure to a wide variety of fields including aeronomy, meteor science, design and construction of radar systems, radio frequency engineering, and software radar.