机载高波段SAR大斜视角大场景成像算法研究

该文基于合成孔径雷达(SAR)斜视成像模式，分析了机载成像处理中斜距展开和二维解耦合近似相位误差与波长、斜视角、分辨率和测绘带宽度等参数的关系，证明二阶近似可满足常规高波段SAR大斜视角成像要求，但改进RD算法的聚集深度问题限制了成像方位孔径，常规CS算法未考虑二次距离压缩(SRC)的空变性，其大场景成像效果均不佳，只有NCS算法考虑了SRC随距离的线性变化，大场景高波段SAR成像聚焦性能最优。对毫米波SAR点目标成像的计算机仿真结果证明了上述分析结果。

Algorithms for the Application of High Squint Large Region Image Formation to Hi-Band Airborne SAR

Based on the squinted mode Synthetic Aperture Radar (SAR), this paper describes the relationship between system parameters (wavelength, squint angle, resolution, swath) and phase errors, which caused by the approximation of slant range and 2-D frequency domain decoupling. The secondary approximation is proven to be accurate enough in normal Hi-band high squint SAR image formation. But, range-focus problem with time domain range walk correction limits the azimuth aperture of the Refined Range Doppler (RRD) algorithm; and the variant space Secondary Range Compression (SRC) causes degradation in the performance of normal Chirp Scaling (CS) algorithms. So with the consideration of variant space SRC, the Nonlinear CS algorithm is suitable for large region high squint imaging. Simulations of a MMW-band SAR system demonstrate the convolution.