Forward and Backscatter of RF Waves by Spherical Overdense Clouds for Several Electron Density Distributions


  • Milton M. Klein


A determination, in geometric optics approximation, of the forward and backscatter characteristics of spherical overdense clouds having (1) a Gaussian decrease with distance from the center, (2) a sech2, or exponential, decay, and (3) an inverse-square decrease, showed that the backscatter cross section for the inverse-square distribution is always larger than for the other two distributions. As the center-point density increases, the backscatter cross section obtained with the Gaussian sphere most rapidly takes on the characteristics of a conducting sphere, that of the sech2 distribution lags slightly behind, but that of the inverse-square sphere never gets close to the result for a conducting sphere. In forward scatter, the inverse-square distribution shows the largest cross section and a fairly rapid increase with center-point density, the sech2 distribution has an essentially constant cross section, and the Gaussian, which has the lowest forward scatter cross section, shows a slight decrease with center-point density.