Improving 3D Reconstruction with Airborne Array-InSAR Images using a Capon-Based Sidelobe Reduction

2D SAR image suffers from distortions such as layover, foreshortening and shadow. These distortions can be well resolved if the surface elevation is determined. However, traditional single-pass InSAR is limited by the phase continuity assumption, which can be mitigated by using the multi-baseline observations. Fortunately, airborne array-InSAR system acquires the multi-baseline in a single flight, but side-lobe will significantly affect the performance of 3D reconstruction. Sparse radar imaging is an efficient way to suppress the sidelobe. In this paper, a capon-based approach is used to reduce the sidelobe and improve the quality of 3D reconstruction. In the practical application, the performance of sidelobe reduction and weak signal protection is contradictory. A trade-off is made by using the similar indicators to get the optimal subaperture size. Experimental results by the real airborne array-InSAR images show that the reducing sidelobe improve the coherence of the weak scatterers, improving the performance of 3D reconstruction.