Effects of platform rotation on STAP performance

The effects of platform rotation, and in particular antenna rotation, on the performance of space-time adaptive processing (STAP) in clutter limited, forward looking airborne radar applications are considered. It is shown that there are two principal mechanisms. One involves the change of shape of the clutter surface in angle-Doppler space as the antenna rotates. STAP appears much more resilient to roll than yaw when this mechanism is dominant, although the problems of yaw can be alleviated by the application of motion compensated phase delay steering. The other mechanism involves the presence of discontinuous sharp transitions across a STAP data vector, for which one possible cause is non-ideal motion compensated steering of the antenna. These discontinuities effectively increase the bandwidth and can result in significant performance deterioration.