单脉冲前视成像技术通过单脉冲测角来提高角分辨率。但是当多个目标处于同一分辨单元时,单脉冲测角只能得到等效散射中心的角度,从而导致目标无法分辨,成像质量变差。针对该问题本文建立了关于多目标到达角的似然函数,通过求解似然函数极值来估计多目标的到达角,实现对目标的准确定位,从而进行准确能量投影。最后,通过仿真实验验证了该方法估计同一距离单元多目标到达角的有效性,实现了不同方位目标角度分辨,并将估计结果应用于前视成像仿真实验,有效改善了图像的质量。
Forward-looking imaging of monopulse angle estimation is a kind of method to improve angle resolution by mono- pulse angle estimation. However, if several targets fall in the same radar beam and the same range bin, monopulse angle estimation can only measure the equivalent angle of all the scatterers. As a result, the angle errors lead to a bad image quality. In this paper, a maximum likelihood function in terms of angles of targets is established to resolve several targets in the same resolution cell and improve the precision of orientation, which enable an accurate projection of targets. By simula- tion, the method is proved to discriminate angles of up to four targets which fall in the same radar beam and range bin, after resolving the maximum likelihood function and applying the algorithm to forward-looking imaging, we can see that the quali- ty of image can be improved effectively.