激光反射断层成像是一种新型的远距离高分辨率成像手段。反射回波可以近似视作发射脉冲和目标反射系数投影分布的加噪卷积,因此发射脉冲的展宽将显著影响重建图像的分辨率。现有的滤波反投影方法不能有效解决这个问题,而脉冲压缩和解卷积可以从回波中还原目标反射率分布投影,进而提高重建图像质量。基于多角度测量的相似性,提出了一种多帧迭代盲解卷积逼近方法,对一维回波信号进行解卷积,并在实际激光雷达上进行了实验,重建结果表明,此算法能显著提高成像的分辨率和细节,并能对发射脉冲给出参考。
Laser reflective tomography imaging is a new approach of long-range and high-resolution imaging. Reflective echo can be approximately considered as the adding noise convolution of transmitted pulse and target reflectance projection distribution. Hence, the broadening of transmitted pulse has significantly effect on resolution of reconstruction image. The existing filtering back-projection algorithm is insufficient to solve this problem effectively, while the pulse compression and deconvolution method can extract target reflectance distribution projection from echo, which will enhance the quality of reconstruction images. Based on the similarity of multi-angle detection, the blind deconvolution of one- dimensional echo signal is proposed based on multi-frame iterative approximation. Experiments are conducted on real laser radar, the reconstructed results show that the proposed method can significantly enhance the resolution and details of imaging, and give reference for the transmitted pulse.