锁模相干激光雷达距离-多普勒成像识别仿真

传统激光相干探测系统中，一般采用单频激光作为发射源，实现目标测量或跟踪；而在国外典型应用中，采用锁模脉冲串与相干接收方式融合，可实现目标距离-多普勒成像（简称R-D成像）。因此，此文重点针对基于锁模CO2激光的R-D成像展开仿真分析。首先建立锁模脉冲串激光模型；其次对频谱混叠进行展开，并结合自旋运动中的目标模型开展回波信号的匹配滤波处理；最后通过相应FFT和IFFT运算，可获得目标的R-D图像，并给出含有噪声情况下、自旋目标在不同转动角速度以及不同脉冲回波相叠加所获的成像质量改善的R-D图。经过相应仿真分析可知，采用基于锁模脉冲串的成像方法，可利用一个大脉冲获得一幅目标R-D图，可作为弹道目标诱饵识别的运动指纹特征。

Range-Doppler imaging recognition simulation of the mode-locked coherent ladar

The emitted laser is a single frequency source in the traditional coherent detection, and this system can be used in the field of objects measuring and tracking. But in the typical ladar system abroad, it can be used in Range-Doppler(R-D) imaging through the mode-locked pulse burst combined with coherent receiving method. Therefore, the numerical simulation of R-D imaging based on the mode-locked laser pulse burst was analyzed. Firstly, the numerical model of the mode-locked pulse burst was built up. Secondly, the unfolded frequency spectral of the laser pulse was given and the matched filter of the echo signal was designed through the spinned-target model. At last, the FFT and IFFT were adopted in the processing while the R-D image can be obtained with different rotating angular speed. On the other hand, the SNR can be enhanced with many frame accumulations based on the R-D image output. From the simulation analysis of R-D imaging, the fingerprint image of the spinned-target with a macro-pulse(including many micro pulses) was obtained, it is very important in the target discrimination of the ballistic missile defense.