Publications Details
Analysis of Electromagnetic Scattering From a Dihedral Cut Into a Sphere Using Vector Spherical Harmonics
Proper calibration or verification of the calibration of fully - polarimetric radar requires more than a simple specular target, such as a conducting sphere or corner reflector. The dihedral reflector is a useful radar - scattering target for calibrating the polarization response of a radar system, because it possesses the ability to change the direction of the scattered electric - field vector in a special way, while a sphere or trihedral target does not. However, the scattered electromagnetic field of a sphere can be computed with arbitrary precision using the well - known Mie series, which is obtained by expanding the scattered field as a series of vector spherical harmonics. In contrast, the computation of the scattered electromagnetic field of dihedral reflectors typically relies on numerical methods or various approximate solutions of Maxwell's equations. Precision calibration of wide - bandwidth polarimetric radar has not been adequately achieved for some applications using this approach. This report describes a method for computing the scattered electromagnetic field of a specially shaped dihedral, derived through the application of a series expansion in vector spherical harmonics, with the goal of achieving the same precision that is available for the sphere.