Research On Ground Penetrating Radar Numerical Simulation And Model Test Inversion

As the geological conditions of various projects in my country have become more complex in recent years,and the difficulty of construction has continued to increase,in order to ensure the safety of various projects,it is particularly important to ensure the reliability and validity of the underground structure survey data during the survey and construction.The traditional drilling method is difficult to meet the engineering needs because of its low detection efficiency,one-sided acquisition of geological data,and destructive testing.As an exploration method with the advantages of low cost,high efficiency and non-destructive testing,the ground penetrating radar method can realize the detection of large-scale underground space in a short time,which is becoming more and more popular in various engineering fields.In practical engineering exploration,due to the influence of surrounding environment,terrain conditions,equipment itself and human factors,the echo signal of GPR will be interfered by direct wave,underground inhomogeneous medium clutter and surrounding random noise,and the useful signal will be covered up,which may lead to the interpretation deviation of radar profile,then cause misjudgment of the geological information of the underground target.In order to improve the effectiveness and accuracy of data interpretation,this paper first provides a reference for the image interpretation of measured data through numerical simulation,and studies the clutter suppression processing in radar echo signal,so as to enhance the quality of target reflection signal and ensure the reliable geological information of underground target:(1)Based on the finite-difference time-domain method,this paper uses GPRMAX software to establish different shapes,different buried depths,different sizes,different antenna center frequencies and different filling types of underground target models,studies the propagation rules of electromagnetic wave in different models,Summarize the influence of the shape,depth and size of the target body on the echo signal and its reflection on the profile.The structure information of the underground target can be judged by the reflected wave signal,which provides a reference for the detection and identification of the actual engineering underground target.(2)In this paper,mean filtering method,median filtering method and wavelet threshold denoising method are used to process the radar echo signal.The results show that wavelet threshold denoising has better noise filtering effect,which can retain the target reflection signal,filter out clutter,improve the quality of radar profile image,and provide help for accurate reading of underground target information.(3)Finally,the measured radar data are denoised by wavelet threshold,which has a good suppression effect on the clutter signal.By comparing the measured radar profile with the numerical simulation image,it is found that the two results are consistent,which indicates that the numerical simulation results have a certain guiding significance for the actual measurement results.Figure [52] table [5] reference [57]...