极化混沌雷达实现非金属管道的高灵敏探测

Underground pipeline detection is an essential work in the construction of urban underground engineering. In various detection methods, Ground penetrating radar (GPR) has been widely used, because it can obtain the pipeline information of unknown region without destroying the surface structure. The GPR can detect the metallic pipeline easily, because the difference of dielectric constant between the metal pipeline and surrounding environment is obvious. However, the GPR is extremely difficult to detect the non-metal pipeline for the difference of the dielectric constant between the non-metal pipeline and surrounding environment is small. The weak echo signal is submerged in the noise signal.. This project proposes a method of polarization chaotic radar for non-metallic pipeline detection. Utilized the polarization chaotic signal as the probe signal, the location of the non-metal pipeline can be realized with the correlation method. The chaotic signal has good anti-jamming capability. And by adjusting the polarization state of the antennas can also suppressed the jamming of the system. Thus, anti-jamming ability of the system is greatly improved, which improves the signal-to-noise ratio of the system and the detection sensitivity of the non-metal pipeline. Furthermore, as the polarization contains information in each direction, the target scattering information is more complete, and it is helpful for the targets recognition.. The implementation of this project is expected to develop a new radar detection technology based on polarization chaos, which provides a new method for the detection of urban underground non-metal pipeline.

地下管线探测是城市地下工程建设的必须环节。在其各种探测方法中，探地雷达因在不破坏地表结构的情况下即可获知地下未知区域的管线信息，极具应用前景。金属管线因与周围环境的介电常数差异明显，因此利用探地雷达可以实现高灵敏探测；而探地雷达对非金属管线的探测率低，原因是非金属与周围环境介电常数差异小，微弱的回波被干扰信号淹没。. 本项目提出一种面向非金属管道检测的极化混沌雷达法。拟采用极化混沌信号作为探测信号，利用相关法实现对非金属管线的定位。由于混沌信号抗干扰能力强，而通过调整天线的极化状态同样能够抑制干扰，使得系统的抗干扰能力得到了显著地提高，进而提高了系统的信噪比和对非金属管道的探测灵敏度。此外，由于回波中包含了各个方向的极化信息，获得的目标散射信息更加完整，有助于提高对目标的识别率。. 本方案的实现有望发展一种新的基于极化混沌的雷达检测技术，为城市地下非金属管道探测提供新的方法。

地下管线探测是城市地下工程建设的必须环节。在其各种探测方法中，探地雷达因在不破坏地表结构的情况下即可获知地下未知区域的管线信息，极具应用前景。金属管线因与周围环境的介电常数差异明显，因此利用探地雷达可以实现高灵敏探测；而探地雷达对非金属管线的探测率低，原因是非金属与周围环境介电常数差异小，微弱的回波被干扰信号淹没。本项目围绕如何提高雷达的抗干扰性能，进而提高对非金属管线的检测率开展研究，主要包括：宽带混沌信号的产生机理与优化设计，基于宽带混沌探地雷达的地下管线探测，混沌信号的噪声抑制算法以及雷达系统的优化。针对上述三项研究内容获得以下结果：. 1）研制了宽带混沌信号发生器，产生了具有理想相关特性、高斯型零均值和速率可调混沌信号作为探测信号。. 2）利用宽带混沌雷达，并结合均值滤波算法和后向投影成像算法，实现对地下管线的探测。该方法同脉冲体制雷达、步进频率体制雷达相比，提高了系统的抗干扰性能，进而提高了对非金属管线的探测率。. 3）优化雷达系统，采用宽带格雷互补码作为雷达探测信号，显著地提高了系统的信噪比，提高了对弱目标的识别能力。. 项目成果显著提升了非金属管线的探测率，为城市地下管线的信息化建设以及城市管线的规划、建设和管理提供可靠的依据，从而减轻、减少管线事故。项目执行期间，在本项目的资助下共计发表论文15篇，其中SCI、EI论文14篇；申请国家发明专利12项，其中已授权专利7项；培养6名博士和硕士研究生。