Research On Ground-Penetrating Radar Denoising Based On Wavelet Adaptive Thresholding Method

With the development of science and technology,people’s demand for the detection of underground structures and underground targets is increasing.As an efficient nondestructive detection technology,ground penetrating radar has received more attention and research.Ground penetrating radar uses the characteristics of different propagation speeds and refraction and reflection of electromagnetic waves in different media,transmits electromagnetic waves through the transmitting antenna,receives electromagnetic waves with the receiving antenna,and uses the processor for processing and imaging,which is convenient for researchers to observe.Therefore,the development prospect of this efficient and lossless technology is very broad.In this paper,the Gpr Max software based on the time domain finite difference method is used to carry out forward modeling simulation to provide stable ground penetrating radar data,and to study the signal processing method of radar data.First,combined with the basic working principle of ground penetrating radar and related knowledge of electromagnetic waves,Gpr Max software is used for simulation modeling,and different simulation models are obtained by writing different input files,so as to provide a stable and reliable data source for ground penetrating radar signal processing research.Then,the ground penetrating radar will be subject to various interferences during the detection process,including: surface direct waves,coupled waves,external noise,etc.So for these noise signals,this paper proposes a denoising method based on wavelet adaptive threshold.By improving the wavelet threshold selection method and threshold function,the threshold is determined by using the sub-band lengths of different layers of wavelet transform to realize adaptive and accurate quantification of the threshold,and more accurate and smooth denoising of ground penetrating radar signals.Through experimental simulation and result analysis,compared with the traditional method,this method can better remove the background noise in the ground penetrating radar signal.Finally,in order to better maintain the details of the target signal and remove background noise at a deeper level,the target signal is clearer and easier to identify.The EEMD algorithm is combined again to decompose and denoise the target signal.Utilizing the EEMD algorithm’s excellent decomposition ability and correlation coefficient screening ability for non-stationary models,the components of different frequencies of the GPR signal can be decomposed and screened,and the main components are processed by wavelet adaptive threshold and reconstructed.The experimental results show that the EEMD joint wavelet adaptive threshold denoising algorithm can greatly improve the denoising ability,better display the details of the ground penetrating radar target signal,and greatly improve the clarity.