EAGER: Thermospheric High Power Rayleigh Lidar

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

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.