After almost of a year of struggling with lasers and the weather, I'm pleased to report that on Friday night (Oct. 1/2) we had a successful 3 h flight test of the Fe temperature lidar. Both laser systems operated flawlessly. Injection seeding was stable throughout the flight and the output power of both lasers exceeded 3.5 W in the UV. Strong Fe returns were observed at 372 nm (~17 counts/shot from Fe layer) and excellent Fe profiles were obtained with integration times as low as 10 s. We even observed a strong meteor trail return in this channel. As expected, the 374 nm returns were significantly weaker (~0.8 counts / shot) but good Fe profiles were obtained with integration times of 5 min or better. We did not have time to test the daytime etalons for the receiving telescopes.
Much of the credit for this success is due to exceptional skills and hardwork of Dr. Xinzhao Chu, Dr. Matt Pfenninger, and Weilin Pan from our group and Norm Zrubrek, Bruce Morley, and their staff at the NCAR-RAF. I can't overemphasize the importance of their contributions and teamwork.
Strong Fe returns were observed on our first attempt to project the beam out of the aircraft and that success brought smiles to the faces of everyone on the flight.
Dr. Chester S. Gardner (Univ. of Illinois at Urbana)