Errors in the retrieval of thin-cloud optical parameters obtained with a two-boundary algorithm

Year: 1998

Authors: Del Guasta M.

Autors Affiliation: Italian National Research Council, Istituto di Ricerca sulle Onde Elettromagnetiche, Via Panciatichi 64, Firenze, 50127, Italy

Abstract: The effect of various errors on the retrieval of optical depth, integrated backscatter, and extinction-tobackscatter ratio in optically thin clouds by use of a two-boundary algorithm is discussed. Uncertainties regarding aerosol loading at the cloud base and top lead to relevant errors that are often larger than those produced by signal noise. Formulas expressing the errors in the lidar-derived optical quantities dependent on optical depth and aerosol uncertainties at the base and top are derived for different fitting procedures. A method for the reduction of errors in the case of consecutive cloud measurements is explored, consisting of the fitting of the retrieved optical-depth-integrated backscatter data to obtain a correct extinction-to-backscatter ratio.

Journal/Review: APPLIED OPTICS

Volume: 37 (24)      Pages from: 5522  to: 5540

KeyWords: Algorithms; Approximation theory; Atmospheric aerosols; Attenuation; Backscattering; Clouds; Curve fitting; Graph theory; Light propagation; Measurement errors; Optical radar; Spurious signal noise, Extinction to backscatter ratio; Klett method; Lidar equation; Molecular backscatter, Atmospheric optics
DOI: 10.1364/AO.37.005522