Preliminary study of STAP on spaceborne sparse array radar for AMTI

Air moving target indication (AMTI) is an important and challenging application for spaceborne sparse radar. The distributed sparse array radar can achieve larger maximum functional range by power synthesis and higher spatial resolution by aperture synthesis. However, the undersampling of sparse array brings grating lobes and high sidelobes in the synthesized pattern, which will cause the blind-zone and angle-ambiguity problems of detection. In the meantime, the high-speed of air moving target will bring range walk within the long coherent processing interval (CPI), which will lead to degradation of detection performance of STAP. These problems can be mitigated by using multi-carrier-frequency technique. The paper presents preliminary simulations to show that the fast air moving target can be detected by a spaceborne sparse array radar using multi-carrier-frequency technique.