The relative merits of pre/post-Doppler STAP

When considering possible implementations of space-time adaptive processing (STAP) techniques, it is apparent that there are two principal approaches; STAP before Doppler filtering (pre-Doppler STAP) and STAP after Doppler filtering (post-Doppler STAP). The two approaches are founded on very different and partly contradicting arguments. This paper tries to collect all these viewpoints. The aim is to give the application engineer, who is not familiar with the details of STAP, a guideline of the basic problem and criteria of choice between pre and post Doppler STAP architectures.