作为永久散射体雷达干涉测量技术的延伸,多基线SAR层析成像技术能够分离单个SAR像素内的多重散射体信号,精确地获取人工地物目标的三维位置和形变信息,突破城市地区形变监测中叠掩效应的制约,实现城市动态形变监测。尤其是新代高分辨军SAR卫星发射成功后,为城市动态形变监测研究提供了大量高分辨军高精度数据源。本文首先介绍SAR层析技术的理论模型,然后归纳了现有的层析算法和应用领域,最后探讨了该技术发展面临的关键问题并展望了其广阔发展前景。
Multi-baseline SAR tomography is an extension of permanent scatterer SAR interferometry (PS-InSAR), in which the distribution of scatterers in the elevation direction and the corresponding reflectivity inside one resolution cell can be retrieved. In this way, TomoSAR aims to provide real and unambiguous 3D SAR imaging; i.e., imaging also in the third coordinate: elevation. In addition to the 3D positions of the superimposed point scatterers, the deformation velocity of each scatterer can also be retrieved using differential SAR tomogFaphy. This new technology can solve the problem of layover effect in urban environments; consequently, deformation surveillance of urban infrastructure becomes possible. Since the launch of the new generation of high-resolution SAR satellites, a huge amount of high-resolution SAR data have been provided for use in urban deformation surveillance. This article illustrated the basic principles of multi-baseline SAR tomogFaphy, and also the development of SAR tomography algorithms and applications, before considering the existing problems associated with SAR tornography research, and the future development of urban deformation surveillance.