Imaging and parameter estimation of moving targets in airborne single-antenna high-resolution SAR system is affected by motion errors,which cause defocusing and dislocation of moving targets.Motion errors involve platform flight deviation and unknown target velocity,and most previous studies treat the two parts as a whole.In that case all motion errors must be compensated together,which overburdens phase estimation,especially in UAV systems.Another challenge for imaging of moving targets is range cell migration correction(RCMC),which mainly includes range walk correction and range curvature correction.Keystone transform is usually used to correct the range walk without knowing radial velocity of the target,but the method is invalid when radial velocity is so high that the shift doppler frequency exceeds azimuth sampling frequency.Quadratic range curvature is often corrected by the flight velocity,neglecting the along-track velocity of the moving target.However,range curvature caused by the along-track velocity becomes significant and cannot be neglected in the high-resolution SAR system.