Grating lobes suppression method for stepped frequency GB-SAR system

A grating lobes suppression method for chirp-subpulse stepped frequency (CSSF) signals is proposed, which is applied to deformation monitoring using the ground based synthetic aperture radar (GB-SAR) system. This method is based on accurate estimation and correction of the phase and amplitude error along two dimensions (range and azimuth), i.e., the error estimation inside the subpulse (in-subpulse error) and across the stepped frequency subpulses (cross-subpulse error) of transmitted CSSF signals. Validated both with simulated data and experimental data recorded in the deformation monitoring campaign, it can be seen that the method as well as the relative conclusions can be fully and effectively applied to most of the stepped frequency systems.