A new synthetic aperture radar autofocusing approach

Uncompensated phase errors presented in synthetic aperture radar (SAR) signals can have a disastrous effect on reconstructed image quality. We present a new method by which arbitrary phase errors can be corrected. The proposed technique is based on a continuous wavelet transform (CWT) analysis of the SAR signal. An approximate explicit expression for CWT is derived under the condition of the radar signal and the mother wavelet being constricted in asymptotic forms. It is demonstrated that the frequency modulation information, which can be used for refocusing the SAR image, can be obtained from the arguments or the moduli of the wavelet coefficients. Finally some simulation results are presented in order to validate the proposed technique.