Dealing with target nulling and clutter inhomogeneities in STAP

Ground Moving Target Indication (GMTI) is a key feature of modern airborne radar systems. For multichannel phased array radar systems, the GMTI performance can be improved by employing Space-Time Adaptive Processing (STAP) for clutter suppression. If targets are present in the secondary data used for estimating the adaptive weights, STAP performance will be degraded, as the homogeneity assumption on the clutter is violated, and even target nulling may occur. This paper presents and analyzes techniques for dealing with target nulling and clutter inhomogeneities in STAP.