In addition to the bulk motion induced by constant velocity or uniform acceleration

the target or any structure on it may undergo micro-motion dynamics

such as mechanical rocking

vibrations

or rotations.The traditional range model approximated by second-order polynomials is not suitable for describing the range from a radar to the micro-motion targets.In this paper

combining with Paired Echo Principle and Range-Doppler(R-D) algorithm in synthetic aperture radar(SAR)

we derive the vector expression which indicates the multi-channel echo of the ground moving micro-motion target in image domain on the basis of setting up its geometrical model

and analyze the azimuth defocusing in single-channel and the interferometric phase between channels induced by micro Doppler.The normalization of the amplitude of the echo of different ghost points and the correlation coefficient of the spatial steering vectors between each ghost point and clutter are introduced.The result of simulation demonstrates that making use of the ghost points to detect the ground moving target has good improvement factor in strong clutter background.