Weibull-distributed weather clutter in the frequency domain

It is pointed out that the Doppler information of radar-received signals has recently been used to improve target detectability in various types of clutter. Thus, a digital signal processor, named the moving target detector (MTD), has been designed to reject ground clutter, rain clutter, 'angels' (birds) and interference. Irabu et al. (1980) have proposed a two-dimensional clutter rejection system. The technique makes use of a Discrete Fourier Transform (DFT) unit, which is cascaded with the aid of range-sweep correlation processing and a conventional cell-averaging LOG/CFAR system in the radial direction. The conventional LOG/CFAR technique is effective only in the case of a Rayleigh distribution. In the present investigation it is shown that Weibull-distributed weather clutter obeys a Weibull distribution in the DFT signal processing. For this reason, the new Weibull/CFAR, discussed by Sekine et al. (1980), should be considered in a two-dimensional clutter rejection system.