Sparse Three-dimensional Imaging Based on Hough Transform for Forward-looking Array SAR in Low SNR
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摘要: 低信噪比下压缩感知稀疏重构的性能不佳,使得前视阵列SAR稀疏3维成像的质量大大降低。为此,该文结合散射系数矢量在原始的距离向和斜距离向2维空间中的连续性特征,借鉴信号检测中常用的直线检测思路和方法,提出基于霍夫变换的压缩感知稀疏重构算法,有效提高压缩感知稀疏重构的性能。同时,仿真实验结果表明,该方法有效实现了低信噪比下前视阵列SAR的稀疏3维成像。Abstract: The performance of sparse reconstruction algorithm of compressive sensing in low Signal-to-Noise Ratio (SNR) is lower, and the quality of sparse three-dimensional imaging for forward-looking array synthetic aperture radar in low SNR is reduced greatly. To solve this problem, a validate method of reconstruction algorithm of compressive sensing based on Hough transform is proposed, in which the continuity of the scattering coefficient vector in the two-dimensional space of range direction and slant range direction and the straight line detection method of Hough transform is used, and thus the reconstruction quality of compressive sensing is increased effectively. Also, the simulation experiments indicate that this method can improve the sparse three-dimensional imaging for forward-looking array SAR in low SNR effectively.
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表 1 前视阵列SAR系统仿真参数
Table 1. Simulation parameters for forward-looking array SAR system
参数 数值 中心波长(mm) 3 脉冲带宽(MHz) 100 脉冲时宽(μs) 1 采样频率(MHz) 120 合成总带宽(GHz) 1 平台速度(m/s) 50 场景中心斜距(km) 1 发射天线高度(m) 499.75 接收天线高度(m) 500.25 跨航向天线长度(m) 6 接收阵元间距(cm) 3 波束中心俯仰角(°) 60 波束中心方位角(°) 0 沿航向合成孔径长度(m) 30 子测绘带波束宽度(°) 3 距离向分辨率(m) 0.15 沿航向分辨率(m) 0.2 跨航向分辨率(m) 0.5 -
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