Use of a Rician Distribution for Modeling Aspect-Dependent RCS Amplitude and Scintillation

A generalized model based on the Rician distribution is proposed as a more inclusive description of a broader variety of targets than can be modeled using the Swerling types. In this approach, both the mean and scintillation of the target RCS can be represented as aspect angle and frequency dependent. The Rician pdf is expressed as a function of two parameters, the fractional contribution of the fixed-amplitude component to the target RCS with the remainder as Rayleigh and the total RCS. The pdf of the RCS of Swerling 3 targets is shown to closely agree with the pdf of a target with 75% of the RCS from a fixed-amplitude scatterer. A parameter estimation procedure for the new model is given and the application of the new model is illustrated with a hollow cylindrical tank and double-ended cone.