Equivalent phase center error bound in MIMO-SAR based on image quality evaluation

The image quality of novel multi-input multi-output synthetic aperture radar (MIMO-SAR) may be degraded with a series of "spurious peaks" in the cross-range direction due to equivalent phase center error. The influence of "spurious peaks" on image quality was analyzed by evaluating SAR image quality using the guidelines of spurious side lobe ratio,integral side lobe ratio and peak power loss. The equivalent phase center error bound in MIMO-SAR was then determined,which benefits MIMO-SAR system design and signal processing. The results show that the equivalent phase center error should be compensated to meet conventional guideline requirements when the error is more than 0.2 rad. Compared with an airborne system,a spaceborne system is more favorable to equivalent phase center processing,usually with the error compensation neglected.