Ray optics approximation for Gaussian random cylinders

We study light scattering by Gaussian random cylinders in the ray optics ap proximation. The random shape is fully described by the covariance function , which can be conveniently modelled by three statistical parameters: the s tandard deviation of radius and the correlation lengths of angular and axia l variations. We present a Fourier-series method for generating sample Gaus sian cylinders and, by studying the total curvature, develop a criterion fo r the validity of the ray optics approximation. We outline a ray tracing al gorithm that can be adapted to almost arbitrary, mathematically star-like p articles in the cylindrical geometry. We study the scattering and absorptio n properties of Gaussian cylinders much larger than the wavelength by syste matically varying their statistical parameters. (C) 1999 Elsevier Science L td. All rights reserved.