EAGER: Thermospheric High Power Rayleigh Lidar

研究人员将开发一种瑞利激光雷达仪器，其中包括一种新型的高功率二极管泵浦YAG激光器。传统的瑞利激光雷达使用8-10瓦脉冲激光器和1米级望远镜，以相对较短的积分时间达到70公里的高度。在80公里以上，需要1小时的整合时间。近年来，脉冲YAG激光器已开发用于商业用途，平均功率为100-1000 W，脉冲重复频率为8 kHz。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，集成时间为一小时或更短。该工程涉及将8千赫（高频）激光脉冲分成8个1千赫的微分离光束，用于时间门控返回到150公里。多光束成像到一个高量子效率，EMCCD成像仪，其中行时钟用于时间范围信息。整个系统结合了新的现有技术，具有低成本、高可靠性的操作，是远程设施仪表的理想选择。仪器开发人员将在新墨西哥州的马格达莱纳岭天文台运行两晚来测试仪器，该天文台有一个直径2.4米的镜子。研究表明，在100至140公里高度之间，中性大气的动态变化非常大。本科生和研究生将参与开发，以帮助培养下一代参与高层大气研究的工程师和科学家。

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.