Generalized Persistent Polar Format Algorithm for Fast Imaging of Airborne Video SAR

Abstract

As a cutting-edge research direction in the field of radar imaging, video SAR has the capability of high-resolution and persistent imaging at any time and under any weather. Video SAR requires high computational efficiency of the imaging algorithm, and PFA has become the preferred imaging algorithm because of its applicability to the spotlight mode and relatively high computational efficiency. However, traditional PFA also has problems, such as low efficiency and limited scene size. To address the above problems, a generalized persistent polar format algorithm, called GPPFA, is proposed for airborne video SAR imaging that is applicable to the persistent imaging requirements of airborne video SAR under multitasking conditions. Firstly, the wavenumber domain resampling characteristics of video SAR PFA are analyzed, and a generalized resampling method is proposed to obtain higher efficiency. Secondly, for the problem of scene size limitation caused by wavefront curvature error, an efficient compensation method applicable to different scene sizes is proposed. GPPFA is capable of video SAR imaging at different wavebands, different slant ranges, and arbitrary scene sizes. Point target and extended target experiments verify the effectiveness and efficiency of the proposed method.

PP-ISEA: An Efficient Algorithm for High-Resolution Three-Dimensional Geometry Reconstruction of Space Targets Using Limited Inverse Synthetic Aperture Radar Images

“…Owing to high-frequency band and wide bandwidth, direct application of the range-Doppler (RD) algorithm for imaging may lead to migration through range cells (MTRC) and resultant defocusing [ 34 , 35 ]. To address this issue, the polar formatting algorithm (PFA) can correct MTRC, enhance image quality [ 36 , 37 ], and facilitate improved reconstruction outcomes.…”

An Extended Polar Format Algorithm for Joint Envelope and Phase Error Correction in Widefield Staring SAR with Maneuvering Trajectory

“…Although time domain imaging algorithms such as back-projection algorithm (BPA) and its modifications can be used for SAR imaging of any complex trajectory and work mode [23][24][25], they have strict requirements for navigation systems and digital signal processing systems, making them challenging to apply for real-time processing. The wavenumber domain polar format algorithm (PFA) is a typical spotlight SAR imaging method that eliminates spectrum aliasing through Deramp processing and achieves two-dimensional focusing through wavenumber spectrum resampling [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. In addition, the implicit keystone transform in PFA can partly alleviate the range cell migration (RCM) caused by radar platform jitter and target motion, which can still effectively correct the RCM even with low inertial navigation accuracy or moving targets [28].…”

FCCD-SAR: A Lightweight SAR ATR Algorithm Based on FasterNet

“…SAR achieves high-resolution imaging through linear FM signals and matched filtering techniques for distance direction, while the azimuth direction employs motion-based virtual aperture synthesis. It possesses remarkable attributes such as all-day [ 6 ], all-weather operability [ 7 ], high penetration capability [ 8 ], long-range observation [ 9 ], and high-resolution ground imaging [ 10 ]. The wealth of surface electromagnetic scattering information offered by SAR has contributed to its widespread adoption in various domains, including ocean exploration [ 11 ], forestry census [ 12 ], topographic mapping [ 13 ], land resource survey, and traffic control, as well as military applications like battlefield reconnaissance, radar guidance, and strike effect evaluation [ 14 ].…”