Research On Key Technology Of Controllable Pulse Ground Penetrating Radar Based On FPGA

Ground Penetrating Radar(GPR)is a non-destructive geophysical measurement device that uses high-frequency electromagnetic waves to acquire information from underground materials.Ground penetrating radar is widely used in engineering inspection,cultural relics archaeology,disaster relief and other fields due to its advantages of fast speed,high precision,and non-destructiveness.With the development of radar technology,people's requirements for ground penetrating radar are getting higher and higher,and the application scenarios of ground penetrating radar are becoming more and more abundant.Therefore,the research on pulse controllable ground penetrating system has important application value and significance.The main contents of this thesis are as follows:Firstly,through the investigation of various documents at home and abroad,first of all,a brief introduction to the ground penetrating radar technology,analysis and summary of the development history of the ground penetrating radar and the development status of the ground penetrating radar technology at home and abroad.Then it introduces the working principle of shock pulse ground penetrating radar,analyzes the signal characteristics of the pulse signal,summarizes the detection parameters of the ground penetrating radar,and proposes a pulse controllable ground penetrating radar scheme on this basis.Secondly,analyze and study the key technology of pulse controllable ground penetrating radar in the process of realization.The analysis shows that the controllable pulse signal has the characteristics of controllable frequency bandwidth and signal parameters.Therefore,FPGA with high transmission rate,large data throughput and strong reconfigurability is selected as the control platform.In the specific system implementation process,FPGA is used to generate a controllable pulse signal based on Direct Digital Synthesizer(DDS)technology;a multi-stage amplifier cascade is supplemented with a controllable attenuator to achieve high dynamics of the signal transmission and reception link Scope;use high-speed ADC chip to effectively collect echo signals;use JESD204 B high-speed communication interface to realize data transmission between FPGA and high-speed DAC and data collection with high-speed ADC.Thirdly,device selection and circuit design of the FPGA control board,high-speed ADC,high-speed DAC,and transceiver link involved in the hardware circuit part of the solution;The pulse generation,high-speed data sending and receiving interface,data buffer and data communication involved in FPGA logic design are implemented and simulated.Finally,according to the design scheme of this thesis,the hardware circuit part of the system was made in kind and the various modules of the system were tested separately.The test results show that the ground penetrating radar system designed in this thesis can effectively transmit and receive controllable pulse signals.After integrating the system,field tests were conducted in the field to verify its ability to detect underground targets.The design of this system is reasonable.The controllable pulse ground penetrating radar system based on FPGA has the characteristics of strong reconfigurability,high transmission rate,large data throughput and controllable pulse signal.