High-Resolution 3-D and 4-D SAR Imaging-The Case Study of Shenzhen

As an extension of synthetic aperture radar (SAR), SAR tomography (TomoSAR) has the ability of three-dimensional (3-D) reflection reconstruction and multi-scatterers separation, and hence obtains the high-resolution 3-D image of focused target. Differential SAR tomography (D-TomoSAR) extends the synthetic aperture principle into the height direction and the time direction, simultaneously. Different from TomoSAR, it can obtain not only the 3-D structure, but also the deformation information of the observed target, which makes four-dimensional (4-D) SAR imaging become possible. Nowadays, it has proved that it is feasible to achieve 3-D and 4-D imaging of urban buildings. However, the performance of TomoSAR and D-TomoSAR still needs to be further improved, especially when the number of used baselines is limited. In this letter, we introduce compressive sensing (CS) technique into TomoSAR and D-TomoSAR imaging. Using 19 meter-resolution spaceborne TerraSAR-X complex image data, we have achieved TomoSAR and D-TomoSAR imaging of artificial targets, and obtained the high-resolution 3-D and 4-D SAR image of representative buildings in Shenzhen.