Research On Image Algorithm Of Chaotic Penetrating Radar

With the improvement of urban infrastructure construction,the underground pipe network becomes more and more complicated,which brings a lot of inconvenience to urban management and maintenance.For historical factors,the missing or incomplete pipes information can cause the pipes to be cut off in the excavation work.And this damage can lead to shut-down of water and electricity,even explosion.Therefore,the accurate information of underground pipe location is an important task in the daily maintenance.As a nondestructive detection method,ground penetrating radar(GPR)has the advantages of high measurement accuracy and simple operation.It is widely used in pipe detection.Through the GPR imaging,the position of underground pipe can be directly displayed.This is convenient for the interpretation of the underground pipe.The classic backward projection imaging algorithm has the disadvantage of serious clutter interference in imaging.To suppress the clutter interference,a correlation weighted back projection imaging algorithm is proposed and is applied to chaotic ground penetrating radar to locate underground pipe.The main work and results are summarized as follows.(1)The classic back projection imaging algorithm and different improved back projection algorithms are summarized and analyzed.In this paper,a correlation weighted back projection imaging algorithm is proposed.It is further applied into chaotic ground penetrating radar.(2)A simulation model of underground pipe location by using chaotic ground penetrating radar is set up.The chaotic signal is used as the transmitting signal and its timing,autocorrelation and power spectrum characteristics are analyzed.The locating principle and data preprocessing method of chaotic ground penetrating radar are described.The proposed correlation weighted back projection imaging algorithm is also explained in detail.Applied the correlation weighted back projection method into the chaotic ground penetrating radar,the theoretical results verify the feasibility of this imaging algorithm.(3)A chaotic ground penetrating radar based on the chaotic pulse position modulation signal is set up.And combined with the correlation weighted back projection method,experiments for underground pipe location are carried out.Compared with different improved back projection imaging algorithms,the correlation weighted back projection method can significantly suppress the interference of clutter.Applied this imaging algorithm into the stepped frequency continuous wave ground penetrating radar,the result proves that the proposed imaging method has the potential to be applied to other radar systems.Furthermore,under the same detection conditions,the chaotic radar has the ability to detect deeper targets compared with the stepped frequency continuous wave ground penetrating radar.