基于外差探测的合成孔径激光雷达成像模拟

Image simulation of synthetic aperture ladar based on the heterodyne detection

根据线性调频信号的特点和光外差探测的原理,推导了合成孔径激光雷达外差探测的输出信号表达式。针对点阵目标模拟了条带工作模式时的数据图像,先对距离向进行傅里叶变换后校正剩余视频项,再对方位向进行相关运算,进而实现了目标图像的重构。推导得到了目标图像在距离向和方位向的解析表达式,分析了目标图像在距离向和方位向的强度分布曲线的特点及其对成像的影响。分析了影响图像分辨率的因素和改进方法,为优化算法和系统设计提供了参考。

Based on the LFM（linear frequency modulation） signal and the principle of the heterodyne, the expression of the output of the heterodyne detection in synthetic aperture ladar was induced in detail. The data image of the array target was simulated in a strip-map mode sequentially. The object image was reconstructed by the method that Fourier transform and some emendation were used in the range direction while the correlation operation was used in the azimuth direction. The analytical expression of the object image was induced in both the range direction and the azimuth direction, so that the intensity distribution of the object image were analyzed in the azimuth direction and the range direction separately. Therefore, many improving methods were advanced by analyzing the factors on the image quality, which may provide many references for further optimization.