Local-DoFs of clutter for arbitrary linear array STAP of airborne radar

Space-time adaptive processing (STAP) technique can mitigate airborne radar clutter and detect moving targets effectively. Based on adaptive radar theory, the degrees-of-freedom (DoF) of a STAP processor should be larger than that of the received clutter. In this article, the local-DoFs of clutter for reduced-dimensional STAP (RD-STAP) methods with arbitrary positioned linear array are studied. The proposed formulas show that the local-DoF of clutter can be approximated by the product of the equivalent clutter bandwidth with the equivalent sampling interval. The results are verified by simulations.