Lidar is a powerful tool for measuring the vertical profiles of aerosols. Dusts are irregularly-shaped particles with varied composition and strong index of refraction variations in the LWIR. We measure dust indices using ellipsometry and transmission through KBr pellets. Milling makes the ellipsometry data less dependent on incidence angle, and the results of measurements on milled materials agree with those from transmission measurements. Measurements show that the spectrum of a milled Arizona Road Dust (ARD) approaches that of pure quartz, indicating a decrease of absorption efficiency for particles larger than the absorption length. These indices of refraction will be used in the future to simulate extinction for the beam of a LWIR lidar.

Date Published: 20 May 2013
PDF: 12 pages
Proc. SPIE 8731, Laser Radar Technology and Applications XVIII, 87310M (20 May 2013); doi: 10.1117/12.2017698

Published in SPIE Proceedings Vol. 8731:
Laser Radar Technology and Applications XVIII
Monte D. Turner; Gary W. Kamerman, Editor(s)