用多方向飞行的全极化SAR图像可能提取特定三维目标的高度与位置信息,进而实现目标物的几何立体重构。全极化SAR图像数据与单极化SAR相比,可以选择多种极化组合数据,提供对于特定目标几何特征敏感的数据类型,通过多方向飞行SAR图像反演该目标或目标群的高度与位置信息。本文用两幅相向飞行的PI-SAR(日本机载极化与干涉SAR,X波段、1.5m分辨率)图像,提取日本仙台电视塔高度、日本东北大学建筑物群的立体重构。

Synthetic aperture radar(SAR) imagery is one of the most advanced technologies in recent two decades in microwave remote sensing.As the resolution reaches a meter order,reconstruction of the 3D stereo objects on the terrain surface from all-weather SAR image becomes more feasible.Due to some technical limitations,conventional radar measurements are mostly restricted to classifying,inverting and reconstructing the stereo objects.It remains for further study via fully polarimetric SAR imagery with high resolution.Since pioneer experiments of SIR-C in 1994,some airborne and satellite-borne polarimetric SAR have been developed.The satellite-borne ALOS phase array polarimetric SAR at L band was launched in January 2006.Canadian Radarsat-2 polarimetric SAR at C band will be in orbit in 2007.How to effectively implement broad applications of polarimetric SAR images has become an extensive topic.The PI-SAR is a Japanese airborne polarimetric and interferometric SAR with two independent radar systems(L band-1.27 GHz,3m resolution,and X band-9.55GHz,1.5m resolution).Interferometric data at X band and only polarimetric data at L band can be obtained.Fully polarimetric data from the square loop flights of PI-SAR over Sendai city,Japan in 2004 becomes available.Multi-directional flights can see the 3D objects in different angles and lead to reconstruction of those stereo objects.In this paper,the images of coherency matrix components derived from polarimetric PI-SAR images of two converse flights at X band,are employed which are mostly characterized by double bounce scattering between the building sides and ground surface,a feasible approach to reconstruct the 3D stereo objects,such as a TV tower and campus buildings is developed.Reconstructions of the building targets are validated by the real ground truth.