Abstract

Measurements of the optical extinction at a wavelength of 1.06 μm have been made in water droplet clouds. The extinction coefficient has been measured in the laboratory using two different methods simultaneously. In the first, measurements of the transmitted signal attenuation over a known path length were used. In the second the extinction coefficient was derived from the two-way attenuation of the signal reflected from a target on the opposite side of the cloud from the laser source and detector. It is found that in general the two values of the coefficient derived differ considerably, and the magnitude of the difference depends on the cloud density, the target size, and the system's optical parameters. The difference is shown to originate in the off-axis forward scattering caused by the cloud droplets, and the implications of the results on the measurement of the atmospheric extinction by reflection (lidar) techniques are discussed.

© 1986 Optical Society of America

Extinction coefficient determination using target reflectance measurements

R. Brent Smith, A. l. Carswell, A. Ulitsky, and J. D. Houston
Appl. Opt. 28(19) 4064-4070 (1989)

Backscatter and extinction measurements in cloud and drizzle at CO₂ laser wavelengths

S. G. Jennings
Appl. Opt. 25(15) 2499-2505 (1986)

Transmitted beam profiles, integrated backscatter, and range-resolved backscatter in inhomogeneous laboratory water droplet clouds

Luc R. Bissonnette, R. B. Smith, A. Ulitsky, J. D. Houston, and Allan I. Carswell
Appl. Opt. 27(12) 2485-2494 (1988)

Determination of cloud microphysical properties by laser backscattering and extinction measurements

R. H. Dubinsky, A. I. Carswell, and S. R. Pal
Appl. Opt. 24(11) 1614-1622 (1985)

Cloud extinction profile measurements by lidar using Klett’s inversion method

Walter Carnuth and Reinhold Reiter
Appl. Opt. 25(17) 2899-2907 (1986)