A fast phase space method for computing creeping rays
2006 (English)In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 219, no 1, 276-295 p.Article in journal (Refereed) Published
Creeping rays can give an important contribution to the solution of medium to high frequency scattering problems. They are generated at the shadow lines of the illuminated scatterer by grazing incident rays and propagate along geodesics on the scatterer surface, continuously shedding diffracted rays in their tangential direction. In this paper, we show how the ray propagation problem can be formulated as a partial differential equation (PDE) in a three-dimensional phase space. To solve the PDE we use a fast marching method. The PDE solution contains information about all possible creeping rays. This information includes the phase and amplitude of the field, which are extracted by a fast post-processing. Computationally, the cost of solving the PDE is less than tracing all rays individually by solving a system of ordinary differential equations. We consider an application to mono-static radar cross section problems where creeping rays from all illumination angles must be computed. The numerical results of the fast phase space method and a comparison with the results of ray tracing are presented.
Place, publisher, year, edition, pages
2006. Vol. 219, no 1, 276-295 p.
creeping rays, high frequency wave propagation, scattering problems, numerical methods, geometrical theory of diffraction, eikonal equation, finite-difference calculation, high-frequency, wave-propagation, travel-time, level set, computation, equation, optics, rcs
IdentifiersURN: urn:nbn:se:kth:diva-16154DOI: 10.1016/j.jcp.2006.03.024ISI: 000242332500018ScopusID: 2-s2.0-33750342435OAI: oai:DiVA.org:kth-16154DiVA: diva2:334196
QC 201005252010-08-052010-08-052010-11-19Bibliographically approved