Application of RTDF to particles with curved surfaces

Abstract

Special issue on XI Conference on Electromagnetic and Light Scattering by Non-Spherical Particles: 2008. Original article can be found at: http://www.sciencedirect.com/science/journal/00224073 Copyright Elsevier B.V. DOI: 10.1016/j.jqsrt.2009.01.011The applicability of the ray tracing with diffraction on facets model is extended to particles with curved surfaces. This allows tests against T-matrix calculations for larger size parameters and modelling of light scattering by more realistic particle shapes, such as ice crystals with rounded edges

Modelling diffraction by facetted particles

“…[12][13][14], external diffraction is approximated by Fraunhofer diffraction on the projected cross section by applying Babinet's principle. Macke [12,13] employed the Kirchhoff approximation to model diffraction by polygonal apertures at perpendicular incidence.…”

“…It is commonly used to calculate the contribution of diffraction to scattering in geometric optics ray-tracing codes (e.g. [12][13][14]). However, in this approach it is wrongly assumed that the propagation direction of the incident wave would be parallel to the normals of the facets containing the edges contributing to the contour of the projected cross section.…”

Electromagnetic scattering by a morphologically complex object: Fundamental concepts and common misconceptions

“…Besides the simplest version of the GOM combining the Snell-Fresnel ray tracing with diffraction on the particle projection, several more sophisticated versions of the GOM have been proposed, such as the GTD and the socalled Kirchhoff approximation (see, e.g., [4,5,29,[39][40][41] and references therein). Like with any phenomenological approach, the range of applicability of these and similar techniques is not well defined, and their quantitative applicability should be extensively examined versus numerically-exact results [41][42][43][44][45][46][47].…”

“…Like with any phenomenological approach, the range of applicability of these and similar techniques is not well defined, and their quantitative applicability should be extensively examined versus numerically-exact results [41][42][43][44][45][46][47].…”

Comprehensive T-matrix reference database: A 2006–07 update

“…[25,70,138,189,190,191]. [27,34,54,68,69,78,85,102,103,109,131,152,167,202,210,[212][213][214]216,218,221,223,236,238,244,249,250]. [23,102].…”