A model for EM propagation through dense clouds of wire dipoles

The scattering of electromagnetic energy by a cloud of wire dipoles, or chaff, is characterized by the radar cross section (RCS) of the cloud. For sparse randomly distributed chaff, the backscatter RCS is the sum of the average uncoupled RCS of the individual dipoles. When the inter-particle distances are small, computations must also account for inter-dipole coupling which is a local effect, and for shielding which is a global effect. Although numerical methods may provide solutions for clouds consisting of a small number of dipoles, they are impractical for application to large dense clouds. In what follows, a new approach is described for computing EM propagation through a chaff cloud of any density, so that coupling and shielding are included. Good agreement with numerical calculations is presented for a case to which numerical techniques may be applied