scholarly journals Near-Field 3D SAR Imaging Using a Scanning Linear MIMO Array With Arbitrary Topologies

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 6782-6791 ◽  
Author(s):  
Bo Fan ◽  
Jing-Kun Gao ◽  
Hong-Jun Li ◽  
Zhi-Jie Jiang ◽  
Yan He
Keyword(s):  
Near Field ◽  
Sar Imaging

RCS Calculation based on Near-Field L1-Regularized SAR Imaging

2021 ◽  
Author(s):  
Yangyang Wang ◽  
Yang Li ◽  
Xiaoling Zhang
Keyword(s):  
Near Field ◽  
Sar Imaging

CBP-based multichannel autofocus for near-field SAR imaging

2011 ◽  
Author(s):  
Hyun Jeong Cho ◽  
David C. Munson, Jr.
Keyword(s):  
Near Field ◽  
Sar Imaging

scholarly journals Unified Approach For Multiscale Radar Cross-Section Measurement by Synthetic Aperture Imaging

2021 ◽  
Author(s):  
Takuma Watanabe ◽  
Hiroyoshi Yamada
Keyword(s):  
Cross Section ◽  
Integral Transformation ◽  
Near Field ◽  
Radar Cross Section ◽  
Synthetic Aperture ◽  
Far Field ◽  
Unified Approach ◽  
Reconstruction Process ◽  
Sar Imaging ◽  
Airborne Sar

<div><div>*This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible.</div></div><div><br></div>In this study, we present an improved and unified approach for image-based radar cross-section (RCS) measurement by 2-D synthetic aperture radar (SAR) imaging with an arbitrary curved antenna scanning trajectory. Because RCS is a quantity defined in the far-field distance of an object under test, direct RCS measurement of an electrically large target is often infeasible owing to the spatial limitation of the measurement facility. The method proposed in this study belongs to the class of techniques referred to as the image-based near-field to far-field transformation (NFFFT) to convert the near-field data of scattering experiment into the far-field RCS. In a previous study, we have developed an NFFFT based on 3-D SAR imaging with an arbitrary antenna scanning surface. However, the previous approach is only applicable to the surface scanning which is impossible for a certain case such as measurement using airborne SAR or vehicle-borne SAR. Therefore, one requires an alternative method that can accommodate an arbitrary scanning curve, which is the subject of this study. We derive a generalized correction factor for image-based NFFFT which is designed to ensure the integral transformation in the image reconstruction process be self-consistent for electrically small scatterers. We provide a series of numerical simulations, an indoor experiment, and an airborne SAR experiment to validate that the proposed scheme can be utilized for various situations ranging from near-field to far-field distance.

scholarly journals High-Resolution Squinted SAR Imaging Algorithm Applied in the Near-Field Environment

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Shijia Wang ◽  
Shibo Wang ◽  
Wanli Liu
Keyword(s):  
Cell Migration ◽  
Near Field ◽  
Synthetic Aperture ◽  
Distortion Compensation ◽  
Imaging Algorithm ◽  
Field Environment ◽  
Imaging Result ◽  
Range Cell ◽  
Sar Imaging ◽  
Range Cell Migration

In the squinted synthetic aperture radar (SAR) imaging of the near-field environment, range-dependent characteristic of squint angle cannot be ignored, which causes azimuth-dependent range cell migration (RCM) after linear range walk correction (LRWC). In this study, an efficient SAR imaging algorithm applied in the near-field environment is proposed. In the processing of the range focusing, LRWC is firstly used to remove the linear RCM. Then, the residual LRCM is expanded into azimuth-invariant and azimuth-variant terms in consideration of the residual LRCM of azimuth-dependent. Range cell migration azimuth scaling (RCMAS) is designed to remove the azimuth-variant term before secondary range compression (SRC) and range compression (RC). In the azimuth focusing, azimuth distortion compensation (ADC) is performed to compensate the azimuth distortion, following which azimuth nonlinear chirp scaling (ANCS) is applied to equalize the frequency modulation (FM) rate for azimuth compression (AC). The simulated results show that more accurate and improved imaging result can be obtained with the proposed algorithm.

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