A differential stratified SAR imaging method based on a subset of small baselines

Differential SAR Tomography (D-TomoSAR) combines D-InSAR and TomoSAR techniques to achieve imaging in the height-deformation velocity (s-v) domain. This method not only addresses the layover problem in SAR imaging but also retrieves the elevation and deformation velocity of individual scatterers within a pixel. It is primarily applied in urban areas with severe layover issues. The quality of elevation imagery and deformation velocity indices in D-TomoSAR data is closely linked to baseline distribution. This study introduces baseline optimization by integrating the small baseline subset (SBAS) technique with D-TomoSAR for the first time. Using the Bao’an District Transportation Administration Bureau in Shenzhen as an example, four-dimensional imaging of urban buildings is realized. Finally, the resolution and reconstruction estimation performance are evaluated through theoretical analysis and case studies.