Summary form only given. A plane electromagnetic wave impinges obliquely upon an electrically long cylindrical target of arbitrary cross section and electrical properties, and scatters from it. The cross-sectional geometry is characterized by a length L, such as a maximal diameter, and the length of the cylinder is H. A two-step hybrid method, which essentially exploits L approximately lambda H has been developed. First, it is assumed that the cylinder is infinite in length; this makes is possible to reduce the problem to a two-dimensional boundary value problem for two unknown scalar potentials. This two-dimensional problem is efficiently solved using a finite-difference scheme with an unstructured grid. From the numerical values of the potentials the three-dimensional electromagnetic fields are reconstructed. Then the scatterer is enclosed by a fictitious circular cylinder which lies far enough away from the target so that the fields behave as outgoing cylindrical waves. Finally, a near-field-to-far-field transformation, is used to extract the radar cross section in the far field.
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