EAGER: Thermospheric Helium (He) Resonance LIDAR Development

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该项目将继续开发氦（He） 1083nm共振双基地激光雷达，该雷达将首次实现对上层热层的激光雷达测量。激光雷达设计和建造的一个关键因素已经实现：在首席研究员（PI）机构开发了一个可调谐的10瓦连续波固态窄带激光发射机，工作在1083 nm。接下来要完成的任务是：(1)升级现有的激光器和传感器元件；(2)通过现场测量证明激光雷达的能力；(3)提高发射机功率，实现移频。第一个任务涉及实现发射机到He谐振线的频率锁定。第二个任务将测试频率锁定发射机，在新墨西哥州索科罗附近的马格达莱纳山脊天文台测量亚稳He密度，高度为10,500英尺，并将其与模型计算进行比较。第三项任务是继续仪器开发，将发射机功率提高到50瓦，并实施移频，以便对He分布进行多普勒采样，从中可以推导出温度和风。就更广泛的影响而言，新型激光雷达将在理论和实验以及先进激光技术方面开辟新的研究领域。它将为现有的非相干散射雷达和成像仪等高层大气仪器提供相关信息。研究生和本科生将大量参与研究活动，并将在仪器设计、开发、测试、校准和操作以及信号处理和数据分析和解释方面获得广泛的培训。新的激光雷达将被用作PI学院的一门工程课程的动手实验工具。最后，该项目确实具有变革性的潜力，无论是在推进激光雷达的设计和开发方面，还是在为高层大气科学提供新的观测能力方面。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This project is for the continued development of a Helium (He) 1083nm resonance bistatic lidar which will achieve the first lidar measurements of the upper thermosphere. A key element in the lidar design and construction has already been attained: a tunable 10-Watt continuous-wave solid-state narrow band laser transmitter operating at 1083 nm has been developed at the Principal Investigator (PI) institution. The next tasks to be completed are to (1) upgrade the existing laser and sensor elements; (2) demonstrate the lidar's capability through field measurements; and (3) increase the transmitter power and implement frequency shifting. The first task involves implementing a frequency lock of the transmitter to the He resonance line. The second task will test the frequency-locked transmitter by measuring metastable He densities at Magdalena Ridge Observatory near Socorro, New Mexico, at an altitude of 10,500 feet and comparing them with model calculations. The third task continues instrument development by increasing the transmitter power to 50 W and implementing frequency shifting in order to Doppler sample the He distribution from which temperatures and winds can be derived. In terms of broader impacts, the new lidar will open new areas of study in both theory and experiment as well as in advanced laser technology. It will provide correlative information for current upper atmosphere instruments such as incoherent scatter radar and imagers. Graduate and undergraduate students are heavily involved in the research activities and will acquire broad training in instrument design, development, testing, calibration, and operation, as well as signal processing and data analysis and interpretation. The new lidar will be used as a hands-on laboratory tool for one of the engineering courses at the PI institution. Finally, the project does have the potential to be transformative, both in furthering lidar design and development and in providing a new observing capability to upper atmospheric science.