Aiming at dealing with the problem of azimuth prefiltering during the interferometric processing procedures

this paper proposed an improved method for InSAR azimuth prefiltering.Based on the theoretic analysis of the InSAR imaging geometry and the principles of coherence

this paper proposes that only the radar echoes coming from the space sampling positions with the same azimuth angles are coherent

i.e.

available for interferometric process.Then an improved method for InSAR azimuth prefiltering is proposed according to the same azimuth angle extension.Finally

The computer simulation and practical examples analysis are shown to prove that the proposed algorithm can improve the coherence between complex SAR images while preserving the coherent information effectively.