Space-time adaptive processing from an airborne early warning radar perspective

Technology improvements over the last decade have made it feasible to consider digital space time adaptive processing, STAP, with associated sophisticated adaptive weight generation algorithms, for airborne early warning (AEW) radar The performance advantages to an AEW radar are significant because of the difficult interference environment it must operate in with large ground clutter returns combined with jamming and casual EMI. As an introduction, the unique aspects of the AEW radar clutter and jamming environment are described. A brief summary of AEW radar trades is presented in order to focus the discussion to specific STAP architectures of interest for the carrier based AEW radar problem. Two specific STAP architectures, pre-Doppler and PRI-staggered post-Doppler; are compared from an implementation and performance perspective. The performance comparisons are made quantitatively with the aid of actual broadband antenna element data and detailed STAP simulations. The paper concludes with a summary of the challenges that lay ahead for the next generation STAP AEW radars.