机载SAR成像信号处理研究和实践

Study and Practice of Imaging Signal Processing for Airborne SAR

成像信号处理是合成孔径雷达 ( SAR)的核心 ,必须根据 SAR系统战技指标的要求 ,设计先进、合理和实用的成像信号处理方案和算法。某型机载 SAR旁视成像模式综合运用二维可分离成像算法、预处理和运动补偿 ,前斜视成像模式综合运用线性距离多普勒成像算法、天线扫描和运动补偿 ,满足了全数字化、机上实时成像的要求。样机试飞中 ,在国内首次获得高清晰度 3 m分辨率的旁视 SAR图像和首次实现高分辨率前斜视 SAR成像。试飞数据在地面处理后 ,在国内首次获得方位分辨率优于 0 .5

Imaging signal processing plays a key role in synthetic aperture radar (SAR). A rational and advanced signal processing scheme is designed according to tactical and technical specifications of the system. This paper deals with a type of airborne SAR operated in side looking and squint looking modes. In the side looking mode, prefiltering, motion compensation and two-dimensional separable image formation algorithm are employed. While in the squint looking mode, antenna scanning, motion compensation, and linear range-Doppler algorithm are used. In test campaign, high quality SAR imageries of 3 m×3 m resolution are achieved in real time on board with full digitization processing. After the test, the azimuth resolution of SAR imageries is higher than 0 5 m, in off-line processing.