大斜视弹载合成孔径雷达信号特性研究

Study on signal properties of missile-borne highly squint SAR

针对大斜视模式下弹载合成孔径雷达(SAR)的运动轨迹特点,分析了该模式下的回波信号特性,基于此建立了信号模型及距离方程,讨论了大斜视弹载SAR系统的多普勒特性、距离徙动特性和距离方程近似精度。仿真结果表明,大斜视弹载SAR回波信号具有大距离走动、小距离弯曲和二阶距离近似误差较大的特点;通过时域去走动、频域去耦合方法,可以获得较好的大斜视弹载SAR成像效果。

The echo signal properties of the missile-borne synthetic aperture radar（SAR） under the highly squint mode are analyzed based on its trajectory characteristics, and the signal model and range equation are proposed. The Doppler centroid, the range cell migration and the slant range ap- proximation accuracy are discussed. The simulation results show that the echo signal of the missile- borne highly squint-mode SAR has the larger range walking, the smaller range curve and serious errors of the second-order approximation, and the missile-borne highly squint SAR can be focused by removing the range walking in time domain and reducing the range-azimuth coupling in the 2-D frequency domain.