EAGER: Thermospheric Helium (He) Resonance LIDAR Development

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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.