一种正前视宽扇区高分辨雷达扫描成像方法

A High-resolution Radar Scan Imaging Method with Right Forward-looking and Wide Sector

合成孔径雷达(Synthetic Aperture Radar,SAR)只有照射到飞行方向左、右两侧的感兴趣成像区域时才能处理出高分辨率SAR图像,飞行方向正前方的成像区域就成为了SAR成像的固有盲区。三通道(和、方位差、俯仰差)毫米波单脉冲成像雷达能够实现对正前视场景的二维成像,获取单脉冲图像。提出对SAR/单脉冲图像进行图像配准和融合拼接的方法:首先利用多尺度多方向二维Gabor滤波器组分别对SAR/单脉冲图像进行特征提取,然后对两组特征矩阵进行归一化互相关匹配,对匹配好的图像进行像素级融合处理,得到完整的正前视宽扇区高分辨雷达图像。试验数据成像处理结果表明,所提复合成像算法能够对飞行正前方宽扇区范围内进行高分辨成像,有效解决了工程实际中碰到的正前视高分辨成像盲区的难题,对于前视雷达成像侦察、弹载雷达目标区域景象匹配、飞行器夜航、盲降等具有一定的工程实际意义。

Synthetic aperture radar(SAR)can process out high resolution SAR images by illuminating the interesting imaging area on the left or right side of the flight direction only,while the right forward-looking area in front of the flight direction is the inherent blind area of SAR imaging.Three-channel(sum,azimuth error,elevation error)millimeter-wave monopulse imaging radar can implement 2-dimensional(2D)imaging on the right forward looking scene and get monopulse images.An image matching and merging method is proposed for SAR and monopulse images.First,feature extraction on SAR and monopulse images is implemented by using multi-scale and multi-direction 2D Gabor filter banks.Then,normalized cross correlation(NCC)matching is used on the two groups of characteristic matrix and pixel mergence on the matched images is taken,so the completely right forward looking and wide sector high resolution radar image is obtained.The imaging results of the experiment data show that the proposed compound imaging method can implement high resolution imaging on the right forward looking and wide sector area of the flight direction.It has effectively resolved the blind area problem of right-forward high-resolution imaging in the engineering practice.It has some practical significance of engineering in forward-looking radar imaging reconnaissance,target area image matching of missile-borne radar,night flight and blind landing of aircraft,etc.