When using active-illumination systems for directed-energy and remote-sensing applications, more often than not a highly coherent laser beam propagates from the source through the atmosphere resulting in partially coherent beam illumination on the target. Interestingly enough, not much literature exists pertaining to the scattering of partially coherent light from rough surfaces. In an effort to bridge this gap, this paper develops a wave-optics simulation approach to the problem at hand. Specifically, the analysis uses two separate phase screens. The first phase screen is located in the source plane and accounts for the size and coherence properties of the incident illumination. Through multiple phase-screen realizations and far field-field propagation from the source plane to the target plane, the first phase screen allows for the generation of spatially partially coherent beam illumination with a Gaussian Schell-model (GSM) form. The second phase screen is located in the target plane and accounts for the surface parameters, i.e., the surface height standard deviation and correlation length. Through multiple phase-screen realizations in the target plane and far field-field propagation to the observation plane, the second phase screen accounts for the interaction of the incident GSM beam with a perfectly reflecting rough surface. This allows for the formulation of the average scattered irradiance and normalized autocorrelation function in the far field. Initial results show that this wave-optics simulation approach compares well with a previously validated 2D scalar-equivalent solution [Hyde et al., Opt. Express 21, 6807 (2013)].

Date Published: 5 September 2014
PDF: 18 pages
Proc. SPIE 9205, Reflection, Scattering, and Diffraction from Surfaces IV, 92050J (5 September 2014); doi: 10.1117/12.2060895

Published in SPIE Proceedings Vol. 9205:
Reflection, Scattering, and Diffraction from Surfaces IV
Leonard M. Hanssen, Editor(s)