EAGER: Thermospheric High Power Rayleigh Lidar

研究人员将开发一种瑞利激光雷达仪器，其中包含一种新的高功率二极管泵浦的YAG激光器。传统的瑞利激光雷达使用8-10瓦脉冲激光和1米级望远镜，可达到70公里的高度，积分时间相对较短。在80公里以上，需要一小时的积分时间。近年来，已研制出平均功率为100-1000W、脉冲重复频率为8 kHz的商用脉冲YAG激光器。即将开发的高功率激光雷达将能够测量高达125公里的高度，积分时间不超过一小时。这项工程包括将8千赫(高频)激光脉冲分成8个1千赫略有分离的光束，以便时间选通返回150公里。多个光束被成像到一个高量子效率的EMCCD成像器，其中使用行时钟来获取时间范围信息。整个系统结合了新的但现有的技术，实现了低成本、高度可靠的操作，是远程设施仪器的理想选择。仪器开发人员将在新墨西哥州的马格达莱纳山脊天文台运行两个晚上来测试该仪器，该天文台有一面直径2.4米的镜子。研究表明，在100至140公里高度之间，中性大气的动力学具有极大的变异性。本科生和研究生将参与这一开发，以帮助培养参与高层大气研究的下一代工程师和科学家。

The investigators will develop a Rayleigh lidar instrument incorporating a new, high-power, diode-pumped YAG laser. The traditional Rayleigh lidars, which use 8-10 Watt pulsed lasers and 1-meter class telescopes, reach altitudes of 70 km with relatively short integration times. Above 80 km, one-hour integration times are required. In recent years, pulsed YAG lasers have been developed for commercial purposes with 100-1000 W average powers and 8 kHz pulse repetition frequencies. The high power lidar to be developed will be able to make measurements up to 125 km altitude with integration times of one hour or less. The engineering involves splitting 8 kHz (high frequency) laser pulses into eight 1 kHz slightly separated beams for time gated returns to 150 km. The multiple beams are imaged to a high-quantum-efficiency, EMCCD imager, where row clocking is employed for time range information. The entire system incorporates new but existing technology, for low cost, highly reliable operations, ideal for remote facility instrumentation. The instrument developers will test the instrument by operating it for two nights at the Magdalena Ridge Observatory in New Mexico, which has a 2.4 m diameter mirror. Studies have shown extreme variability in the dynamics of the neutral atmosphere between 100 and 140 km altitude. Undergraduate and graduate students will be involved with the development to help train the next generation of engineers and scientists involved in upper atmospheric studies.