Long synthetic aperture is required in high squint SAR imaging

which is severely influenced by the nonstationarity of airplanes.Therefore

motion compensation is crucial in high squint SAR data processing.A motion compensation approach integrated with the imaging algorithm is proposed.Firstly

the expression of instantaneous Doppler chirp rate is given according to the image geometry model of high squint SAR.Then

the components of motion errors are separated and estimated

using the Doppler chirp rate estimated from measured data and the parameters of inertia navigation system (INS).After that

the envelope and phase corrections are performed in high squint SAR data through the obtained motion errors.The effectiveness of the proposed approach can be verified by the imaging results of simulation data and measured data.