TABLE OF CONTENTS Definition of radar cross section (RCS)
The RCS of a sphere
RCSs of some simple shapes based on simple theory
Wavelength dependence of RCS
Optical, resonance, and Rayleigh regions
Effect of polarization
Mitigating polarization effects
RCS of dipoles and clouds of dipoles (chaff)
The RCS of various types of clutter
Clutter fences
Inferring physical characteristics from RCS (radar signature)
Radar cross section (RCS) is a measure of the electromagnetic energy intercepted and reradiated at the same wavelength by any object. The dimensions are those of an area, usually square meters (m 2) or decibels relative to a square meter (dBsm). The relationship between square meters and dBsm is given in Equation (4.1). The RCS of an object is a complex combination of multiple factors: size, shape, material, edges, wavelength, and polarization. Simple objects tend to have a single, or few, scattering sources. Complex objects (such as airplanes) tend to have multiple scattering sources (e.g., nose, fuselage, inlet, wing root, wing, and so forth). Thus, for complex objects, the RCS is the complex (amplitude and phase) combination of contributions from each scattering source.
The understanding of RCS concepts generally starts with an idealized object that is large with respect to a wavelength, has an intercept area of one square unit, is perfectly conducting, and reradiates isotropically. It is easy to build an object with these characteristics; a copper sphere is an example. Providing it is large with respect...
