SAR/GMTI is one of the stresses in SAR field.Crucial technique for SAR/GMTI is suppressing the main beam clutter

for the ground-moving target echo is often shaded by main beam clutter (echo from stationary background).First we point out the difference between clutter-suppression method studied (called RDATI) and the traditional SAR/GMTI algorithms (called DPCA)

the former is space-frequency procession and the latter is space-time procession.Space-Frequency filter for RDATI is given out.Next we analyze the system parameters that will influence the clutter residue after RDATI suppression.In the third part we analyze the principle and the degree that moving targets echo can be retained after RDATI procession.