The RSMI algorithm for airborne MTI radar

We introduce a new space-time adaptive processing (STAP) algorithm for clutter mitigation in airborne MTI radar systems. The algorithm, named RSMI, is order-recursive and allows data processing in the fast-time, an idle period for most algorithms (data acquisition period). We show that the RSMI optimum output converges in the mean-square sense to the SMI optimum output as the number of pulses increases from 1 to the SMI order, always with smaller computational cost. We also show that the whole CPI may not be required to obtain satisfactory performance. Thus, the new algorithm opens the possibility of real-time adaptation to further reduce complexity