Synthesis of a Digital Clutter Generator for Radar Applications

The radar return from a group of distributed scatterers exhibits a fluctuating nature whose intensity and rate of change appear to be a function of the frequency of the radiation and the motion of the scatterers. Because of their appearance on radar displays, the fluctuating echo signals are referred to as clutter. A digital computer synthesis of a simulated ground clutter signal is presented in which the clutter is characterized by its power spectral density and probability density functions. The output of a random number generator producing uniformly distributed white noise is shaped to yield a sequence of numbers having a Gaussian probability density function. The Gaussian, white noise is then filtered to yield the desired power spectral density. Equations are derived which relate the noise statistics to the shaping and filtering operators. Experimental results are presented to illustrate the clutter characteristics that have been obtained utilizing an available noise generator.