A New Structure-Based Coregistration Method for Near-Field Ground-Based MIMO Tomographic SAR

Image coregistration is a key step in tomographic SAR (TomoSAR) signal processing, and the quality of coregistration directly determines the tomographic results. Traditional coregistration is performed based on the far-field assumption, where the scattering characteristics remain constant with different look angles and distances. However, for near-field TomoSAR observation, the traditional coregistration method will fail because of the mismatch caused by the change of scattering characteristics. In this study, we propose a new structure-based coregistration method for near-field ground-based MIMO TomoSAR. Corse coregistration based on the structure and fine coregistration combining correlation function and singular modification are conducted to achieve coregistration accurately and robustly. The validity of the presented approach is validated by real data.