High-Resolution Imaging of Multi-Channel Forward-Looking Synthetic Aperture Radar Under Curve Trajectory

Abstract

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.

Curvilinear Flight Synthetic Aperture Radar (CF-SAR): Principles, Methods, Applications, Challenges and Trends

“…With the gradual implementation of these multi-channel SAR systems, the problem of multi-channel SAR signal processing under a curvilinear trajectory is bound to be an urgent challenge to be solved. To the best of our knowledge, there are very few studies on multi-channel CF-SAR at present, and most of them focus on forward-looking imaging [82,83]. Nevertheless, some common issues of multi-channel SAR, such as efficient signal reconstruction [84], channel calibration [85], more flexible channel configurations [86][87][88][89][90][91], more novel imaging modes [91][92][93][94], etc., also need to be solved in the research corresponding to CF-SAR, making it even more difficult for CF-SAR to be solved.…”

Spatial-Variant SAR Range Cell Migration Correction Using Subaperture Strategy

“…The highly squinted operating model [ 1 , 2 ] is widely used in the practical application of airborne synthetic aperture radar (SAR) [ 3 ], which has the advantages of higher mobility and flexibility to observe the areas of interest. However, the signal coupling of the range and azimuth in the highly squinted mode is more serious than that in the broadside mode, which also brings more problems for signal processing.…”

High-Precision Imaging Algorithm for Highly Squinted SAR With 3D Acceleration

“…By the employment of motion compensation [7], a modified nonlinear chirp scaling (MNLCS) was adopted in [5] to handle the 3D acceleration problems, while it has a limited scope of application. Lu et al [8] proposed a multi-antenna approach for the forward-looking high-resolution SAR imaging under the curve trajectory. Liu et al [9] analyzed the error of the nonlinear trajectory.…”