Abstract: The incoming radar signals to a constant false alarm rate (CFAR) processor, having some known cumulative distribution function F(X) or probability density function f(X), are transformed into new signals Y according to the equationY=.sigma.[-1n {1-F.sub.x (X)}].sup.1/Kwhere .sigma. and K are a scale parameter and shape parameter, respectively, and can be arbitrarily set. The threshold to which the processed signal is compared in the CFAR processing is variable in accordance with the selected value of K.

Abstract: In an MTI radar receiver, a clutter suppressor (46, 47, 48) is switched (72), under the control of a discriminating device (71) responsive either to the shape parameter .eta. of the Weibull distribution or an average level of a clutter suppressed signal, to be selectively operable as a Weibull and a Rayleigh clutter suppressor for best possible LOG/CFAR processing with simple cell averaging circuitry. The suppressor may comprise a first processor (61) combined with an .eta. parameter calculator (48) for converting the Weibull clutter to the Rayleigh clutter, a second processor (89) for timing, and a simple suppressor (62) for the Rayleigh clutter. (FIG. 6).

Abstract: A moving target indication radar rejects clutter by employing a suppressor having a threshold level variable in accordance with the detected shape parameter .eta. of the Weibull distribution.

Abstract: A moving target indication radar (MTI) having a high azimuthal position detection accuracy. The received radar return signal is separated into quadrature components which are each converted to a series of digital samples. A continuous discrete fast Fourier transform is then performed on groups of samples corresponding to a predetermined number of contiguous azimuthal units of identical range producing an equal number of output Doppler frequency components which represent the relative speeds of stationary and moving objects within the contiguous azimuthal units. A new separate transform operation is performed for each new sample received. The transform outputs are processed to separately detect the stationary and moving objects.

Abstract: A moving target indication radar is disclosed in which the zero-Doppler-speed components of the radar return signal are eliminated by correlation processing in the azimuthal direction. In some cases, a similar correlation processing is concurrently performed in the range direction. The moving target indication radar has both a radar signal analog processing portion and a radar signal digital processing portion. The received pulse returns are processed by quadrature phase detectors to provide outputs which are in phase and quadrature phase analog data signals representing real and imaginary parts of the Doppler frequency data. These signals are converted to corresponding digital words which are then divided into a plurality of digital Doppler frequency components by a discrete Fourier transform circuit. A buffer memory is connected to store the outputs of the discrete Fourier transform circuit.