Space-time Adaptive Fir Filtering with Staggered Pri

Space-time least squares FIR filters have proven excellent clutter rejection performance at extremely low computational load so that ground moving target indication (GMTI) kann be carried out in real-time. Staggering the pulse repetition interval (PRI) is an appropriate way of avoiding Doppler ambiguities and blind velocities. Fully adaptive space-time processors can cope well with staggered echo data. FIR filtering techniques are based on constant PRI and, therefore, will suffer some degradation if the radar pulses are staggered. In this contribution the concept of re-adaptation of the FIR filter coefficients at each PRI is put forward. It is shown by simulations that the total loss caused by staggering the PRI is of the order of magnitude of a few dB. However, applying a constant FIR filter to staggered data results in dramatic losses in signal-to-clutter+noise ratio.