For airborne interferometric synthetic aperture radar (InSAR) data processing, it is essential to achieve precise motion compensation to obtain high-quality digital elevation models (DEMs). In this paper, a novel InSAR motion compensation method is developed, which combines the backprojection (BP) focusing and the multisquint (MSQ) technique. The algorithm is two-fold. For SAR image focusing, BP algorithm is applied to fully use the navigation information. Additionally, an explicit mathematical expression of residual motion error (RME) in the BP image is derived, which paves a way to integrating the MSQ algorithm in the azimuth spatial wavenumber domain for a refined RME correction. It is revealed that the proposed backprojection multisquint (BP-MSQ) algorithm exploits the motion error correction advantages of BP and MSQ simultaneously, which leads to significant improvements of InSAR image quality. Simulation and real data experiments are employed to illustrate the effectiveness of the proposed algorithm.

Target three-dimensional (3D) reconstruction is a hot topic and also a challenge in remote sensing applications. In this paper, a new reconstruction algorithm is proposed to reconstruct the 3D surface of the stable attitude target from its multi-view radar image sequence. Uniform explicit expression of the radar and optical imaging geometries is derived to bridge the 3D target structure and these two sorts of observation images. In this way, the visual hull of the target is reconstructed by exploiting the multiview stereo techniques to the silhouette information extracted from the radar image sequence. Meanwhile, the target absolute attitude is also determined. Furthermore, we analyze the primary difficulty of the method induced from the limited radar observation view in a typical application, the 3D reconstruction of an in-orbit satellite. Then, an extended algorithm is proposed with the feature fusion of the radar and optical images to achieve dramatic performance enhancement of the reconstruction in this condition. The feasibility of the proposed algorithm is confirmed in the experiment part, and some conclusions are drawn to guide the future work about extended applications of the proposed algorithm as well.INDEX TERMS Radar imaging, geometrical projection, three-dimensional reconstruction, feature fusion of the radar and optical images.

Forward-looking synthetic aperture radar is an essential tool in modern remote sensing applications, but its imaging is a challenging task. Few existing methods consider the curve trajectory. Aiming at the difficulty of resolution and the Doppler ambiguity in forward-looking SAR under the curve trajectory, this paper establishes a forward-looking multi-channel SAR system model and proposes a novel approach for the forward-looking SAR imaging under the curve trajectory. The approach is implemented by a two-step process: 1) The Doppler ambiguity under forward-looking mode is solved by adaptive beam-forming processing; and 2) A sparsity-driven optimization imaging algorithm is developed to enhance the azimuth angle resolution in the forward-looking direction, where the resolution gain aroused by the curve trajectory is exploited. The extensive simulation confirms the validity of the proposed approach.

No abstract

No abstract