论文部分内容阅读
利用地质雷达(GPR)提前识别、探明裂隙对于认识岩体结构、预防岩体灾变十分重要,由于多次反射、绕射等问题,地质雷达对于较复杂裂隙网络的探测结果识别解译困难,后向投影(BP)算法能够获得高分辨的雷达成像,但是传统BP算法成像中杂波干扰严重,降低了地质雷达成像效果和分辨率。据此提出了改进BP算法,利用待成像点在各道上的雷达响应值之间的相关性,通过2次快速互相关操作增强了对其他点的干扰的抑制作用,并采用电磁波衰减补偿系数对地质雷达成像结果进行补偿,实现提高地质雷达的成像效果的目的。针对几种典型的岩体裂隙网络开展了地质雷达正演模拟和基于改进BP算法的成像仿真,同时利用物理模型试验进行了验证,发现利用基于改进的BP算法可以实现对裂隙网络的位置和形态进行成像,与传统的BP算法相比具有更强的干扰抑制效果。
It is very important to identify and detect the fissures by using the GPR in advance to recognize the rock mass structure and prevent the rock mass catastrophe. Due to the multiple reflection and diffraction problems, the GPR can not recognize and interpret the exploration results of the complex fracture network. Back-projection (BP) algorithm can obtain high-resolution radar imaging, but the clutter interference in the traditional BP algorithm is serious, reducing the imaging effect and resolution of the GPR. Based on this, an improved BP algorithm is proposed, which utilizes the correlation between the radar response values of the spots to be imaged on each track and enhances the suppression of the interference to other spots through two fast cross-correlation operations, and uses the electromagnetic wave attenuation compensation coefficient pair Geological radar imaging results to compensate, to achieve the purpose of improving the imaging effect of geological radar. For several typical rock fracture network, GPR forward modeling and imaging simulation based on improved BP algorithm are carried out. At the same time, the physical model test is used to verify that the location and shape of the fracture network can be achieved by using improved BP algorithm. Imaging, compared with the traditional BP algorithm has a stronger interference suppression.