scholarly journals CONVOLUTION BACK-PROJECTION IMAGING ALGORITHM FOR DOWNWARD-LOOKING SPARSE LINEAR ARRAY THREE DIMENSIONAL SYNTHETIC APERTURE RADAR

2012 ◽  
Vol 129 ◽  
pp. 287-313 ◽  
Author(s):  
Xueming Peng ◽  
Weixian Tan ◽  
Yanping Wang ◽  
Wen Hong ◽  
Yirong Wu
Keyword(s):  
Synthetic Aperture Radar ◽  
Linear Array ◽  
Three Dimensional ◽  
Synthetic Aperture ◽  
Back Projection ◽  
Imaging Algorithm ◽  
Sparse Linear Array ◽  
Aperture Radar

scholarly journals Precision Downward-Looking 3D Synthetic Aperture Radar Imaging with Sparse Linear Array and Platform Motion Parameters Estimation

2018 ◽  
Vol 10 (12) ◽  
pp. 1957 ◽  
Author(s):  
Qiyong Liu ◽  
Ying Luo ◽  
Qun Zhang ◽  
Wen Hong ◽  
Tat Yeo
Keyword(s):  
Synthetic Aperture Radar ◽  
Linear Array ◽  
Three Dimensional ◽  
Synthetic Aperture ◽  
Platform Motion ◽  
Yaw Rate ◽  
Sparse Linear Array ◽  
Sar Imaging ◽  
Cross Track ◽  
Aperture Radar

The downward-looking sparse linear array three-dimensional synthetic aperture radar (DLSLA 3D SAR) has attracted a great deal of attention, due to the ability to obtain three-dimensional (3D) images. However, if the velocity and the yaw rate of the platform are not measured with enough accuracy, the azimuth signal cannot be compressed and then the 3D image of the scene cannot be obtained. In this paper, we propose a method for platform motion parameter estimation, and downward-looking 3D SAR imaging. A DLSLA 3D SAR imaging model including yaw rate was established. We then calculated the Doppler frequency modulation, which is related to the cross-track coordinates rather than the azimuth coordinates. Thus, the cross-track signal reconstruction was realized. Furthermore, based on the minimum entropy criterion (MEC), the velocity and yaw rate of the platform were accurately estimated, and the azimuth signal compression was also realized. Moreover, a deformation correction procedure was designed to improve the quality of the image. Simulation results were given to demonstrate the validity of the proposed method.

scholarly journals Focusing High-Squint Synthetic Aperture Radar Data Based on Factorized Back-Projection and Precise Spectrum Fusion

2019 ◽  
Vol 11 (24) ◽  
pp. 2885
Author(s):  
Lei Ran ◽  
Zheng Liu ◽  
Rong Xie ◽  
Lei Zhang
Keyword(s):  
Synthetic Aperture Radar ◽  
Real Data ◽  
Radar Data ◽  
Synthetic Aperture ◽  
Back Projection ◽  
Motion Error ◽  
Synthetic Aperture Radar Data ◽  
Imaging Algorithm ◽  
Polar Coordinate ◽  
Aperture Radar

This paper presents a microwave imaging algorithm for high-squint airborne synthetic aperture radar (SAR), which combines back-projection and spectrum fusion together. Two spectrum center functions are proposed for linear and nonlinear trajectories respectively, which are the main contributions of this paper, and not considered in conventional work for high-squint SAR. For linear trajectory, the whole aperture data is first divided into sub-apertures with equal length, and the sub-aperture data is backprojected to a unified polar coordinate to generate multiple low-resolution sub-images. Then, these sub-images are corrected by an accurate spectrum center function, which is caused by the presence of squint angle. After spectrum center correction, spectrums of these sub-images can be coherently connected in cross-range wavenumber domain, generating the whole aperture spectrum. Next, the full-resolution image can be obtained by cross-range Fourier transform. For nonlinear trajectory, the deviations introduce extra spectrum shift, which degrades the focusing performance. Another spectrum center function is proposed according to angular-variant motion-error model, which helps to perform precise spectrum fusion. The proposed imaging algorithm is called high-squint accelerated factorized back-projection (HS-AFBP), and it helps to improve the focusing precision. Both the simulation and real data experiments validate the effectiveness of the proposed HS-AFBP algorithm.

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