Theoretical and Experimental Study of Propagation in 3D Tunnels

Kazunori UCHIDA  Hidetoshi NOSE  Hiroshi MAEDA  Toshiaki MATSUNAGA  

IEICE TRANSACTIONS on Communications   Vol.E87-B   No.10   pp.3044-3049
Publication Date: 2004/10/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Antennas and Propagation
propagation,  closed space,  ray tracing,  reflection,  diffraction,  

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This paper is concerned with the application of ray tracing method (RTM) to field analysis in bended and branched tunnels. On the line of sight, direct wave from a source and reflected waves at the tunnel walls are dominant compared with diffracted waves, but off the line of sight, diffraction can not be ignored especially beyond an abrupt bending. As a result, a detailed attention should be focused on the RTM analysis when dealing with propagation in the region off the line of sight. In this paper, we take into account of the diffraction rays which are originally reflection rays, next diffracted at a bending edge, and again converted to reflection rays. It is shown that numerical results are in good agreement with the experimental data.