Target detection and angle estimation using 3 channel ΣΔ STAP

ΣΔ STAP which uses sum and difference beams of an antenna has significant practical advantages in clutter suppression. On the other hand, when we use ΣΔ STAP for target detection, we use mono-pulse strategy to estimate off-axis target angle. However, signals used for target estimation are contaminated by clutter and induce erroneous result. The conventional ΣΔ STAP is modified to estimate target angle accurately and to improve target detectability, simultaneously.