Design procedure for improving the usable bandwidth of an MTI radar signal processor

A technique is presented for improving the bandwidth throughout which a radar return can be detected while keeping the ground-clutter power rejection below an acceptable level. The processor employs a high-pass digital filter which has been designed in accordance with the McClellan-Parks algorithm with the pass-band lower edge selected in an optimum fashion when the other filter design parameters are specified. Conventional approaches to the design of a moving-target indicator (MTI) filter such as the three-pulse canceller and the covariance design method typically improve the signal-to-noise ratio over less than 50% of the range between dc and the pulse-repetition frequency whereas this technique extends the usable bandwidth to 80% or more. A design example is included which utilizes parameter values from a C-band radar and demonstrates the interactive influence of such filter parameters as the number of weights, passband ripple and bandedge, and stopband attenuation and cut-off.