A High-Resolution Spotlight Imaging Algorithm via Modified Second-Order Space-Variant Wavefront Curvature Correction for MEO/HM-BiSAR

被引：0

作者：

Ren, Hang ^{[1
]}

Lu, Zheng ^{[2
]}

Li, Gaopeng ^{[1
]}

Zhang, Yun ^{[1
]}

Yang, Xueying ^{[1
]}

Guo, Yalin ^{[3
]}

Li, Long ^{[1
]}

Qi, Xin ^{[4
]}

Hua, Qinglong ^{[1
]}

Ding, Chang ^{[5
]}

Mu, Huilin ^{[6
]}

Du, Yong ^{[7
]}

机构：

[1] School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin,150001, China

[2] Institute of Remote Sensing Satellite, China Academy of Space Technology, Beijing,100094, China

[3] School of Mathematics and Statistics, Beijing Institute of Technology, Beijing,100081, China

[4] Beijing Institute of Astronautical Systems Engineering, Beijing,100076, China

[5] Shaanxi Key Laboratory of Artificially Structured Functional Materials, Air Force Engineering University, Xi’an,710051, China

[6] Air Defense and Antimissile School, Air Force Engineering University, Xi’an,710051, China

[7] China Mobile Chengdu Institute of Research and Development, Chengdu,610213, China

来源：

Remote Sensing | 2024年 / 16卷 / 24期

基金：

中国国家自然科学基金; 中国博士后科学基金;

关键词：

Forward error correction - Signal to noise ratio - Thermography (imaging) - Tropics;

D O I：

10.3390/rs16244768

中图分类号：

学科分类号：

摘要：

A bistatic synthetic aperture radar (BiSAR) system with a Medium-Earth-Orbit (MEO) SAR transmitter and high-maneuvering receiver (MEO/HM-BiSAR) can achieve a wide swath and high resolution. However, due to the complex orbit characteristics and the nonlinear trajectory of the receiver, MEO/HM-BiSAR high-resolution imaging faces two major challenges. First, the complex geometric configuration of the BiSAR platforms is difficult to model accurately, and the ‘non-stop-go’ effects should also be considered. Second, non-negligible wavefront curvature caused by the nonlinear trajectories introduces residual phase errors. The existing spaceborne BiSAR imaging algorithms often suffer from image defocusing if applied to MEO/HM-BiSAR. To address these problems, a novel high-resolution imaging algorithm named MSSWCC (Modified Second-Order Space-Variant Wavefront Curvature Correction) is proposed. First, a high-precision range model is established based on an analysis of MEO SAR’s orbital characteristics and the receiver’s curved trajectory. Based on the echo model, the wavefront curvature error is then addressed by two-dimensional Taylor expansion to obtain the analytical expressions for the high-order phase errors. By analyzing the phase errors in the wavenumber domain, the compensation functions can be designed. The MSSWCC algorithm not only corrects the geometric distortion through reverse projection, but it also compensates for the second-order residual spatial-variant phase errors by the analytical expressions for the two-dimensional phase errors. It can achieve high-resolution imaging ability in large imaging scenes with low computational load. Simulations and real experiments validate the high-resolution imaging capabilities of the proposed MSSWCC algorithm in MEO/HM-BiSAR. © 2024 by the authors.

引用

共 1 条

[1] Space-variant filtering for correction of wavefront curvature effects in spotlight-mode SAR imagery formed via polar formatting
Jakowatz, CV
Wahl, DE
Thompson, PA
Doren, NE
ALGORITHMS FOR SYNTHETIC APERTURE RADAR IMAGERY IV, 1997, 3070 : 33 - 42

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