Research And Simulation Design Of Frequency Stepping Ground Penetrating Radar Signal Source And Signal Processing

Ground Penetrating Radar(GPR)is a non-destructive detection technology that utilizes the reflection and scattering of radar signals between different underground media to achieve geological structure imaging,underground target positioning,and underground target detection.Due to the characteristics of high-precision,high-efficiency,and non-destructive detection,ground penetrating radar(GPR)detection is currently mainly used in archaeology,mineral exploration,disaster geological investigation,geotechnical engineering investigation,engineering quality testing,building structure testing,and military target detection.In addition,using ground penetrating radar to remotely detect outer planets has become a new technology hotspot in recent years.The Mars Express probe has carried a MARSIS scanning stepper radar to complete in orbit ground penetrating exploration of Mars.China has also used the Yutu and Tianwen spacecraft to carry ground penetrating radars to explore the moon and Mars.Currently,space-based ground penetrating radar systems typically have several characteristics: the using of pulse signals for detection,the need for large instantaneous bandwidth and transmission power to achieve high resolution,high-speed analog-to-digital conversion(ADC),and so on.Due to the fact that such radars are typically used for deep space exploration,the programs burned on their hardware are immutable,and the hardware is not maintainable.At the same time,due to the limitations of the weight of the payload,requirements for such ground penetrating radars such as small weight and simple hardware structure are proposed.This thesis uses stepped frequency signals as signal sources,and targets a software based stepped frequency ground penetrating radar based on Universal Software Radio Peripherals(USRP).The radar signal system,system architecture,and data processing methods are designed,and the design is verified by simulation.In order to reduce the requirements on the instantaneous bandwidth of the radar while obtaining high transmission power and high spatiotemporal resolution,the radar signal adopts stepped frequency continuous wave(SFCW),which is processed to synthesize a range profile with high resolution.In this study,based on the physical model of radar signal transmission and the mathematical model of signal system,a MATLAB simulation program was developed to numerically simulate the ranging function of frequency stepping signals,and the feasibility of applying frequency stepping continuous wave to ground penetrating radar was analyzed.On this basis,the design and development of a software based radar architecture based on the GNU Radio software radio platform and closed-loop experiments have been completed,and the radar data processing methods have been designed.Based on GRPMAX,simulation tests have been conducted on the radar’s signal processing and data processing,especially its functions such as interference removal,target detection,image offset,and wave velocity estimation.The test results show that the design can achieve high spatiotemporal resolution underground structure detection based on stepped frequency continuous wave and software radar architecture.This study lays the foundation for the subsequent implementation of a ground penetrating radar system based on the general software radio platform.