Computerized ray optics method of calculating average value radar cross section

Abstract

In attempting to estimate the radar cross section of airborne vehicles, it is often only necessary to consider average values of the radar returns. A method of providing a quick estimate of the average bistatic radar cross section of the vehicle components would be useful. Ray optics provides a method of predicting the radar cross section of electrically large, perfectly conducting, simply curved, convex bodies such as spheres, ogives, ellipsoids, etc. This paper extends the method of ray optics to the case of an arbitrary body, which may be concave and/or convex, on which doable reflection and depolarization can occur. The incident radiation on the scattering body is represented by a large number <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(10^{5}-10^{6})</tex> of rays. The rays reflected in a given direction with a given polarization are collected at infinity and combined by phasor addition. For the bodies investigated, this method yields results within <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\pm2</tex> dB of measured results except in small angular regions where trapped waves contribute significantly to the radar return.