Design Of Ground-penetrating Radar Acquisition System Based On Random Equivalent Sampling

In this paper,a ground-penetrating radar acquisition system based on random equivalent sampling is designed to address the problems of low measurement accuracy and unsynchronized transceiver system,which uses ADC+FPGA to achieve the acquisition and recovery of echo signals.The main research contents are as follows.(1)Acquisition system receiving module design.The ground-penetrating radar signal reception principle and echo signal characteristics are analyzed and studied,and a data reception module design scheme based on programmable logic chip and high-speed ADC is designed to complete the acquisition of nanosecond echo signals.(2)Research on the correction method of time spreading circuit.The time spreading circuit is the core module of the random equivalent sampling system to realize the data recovery of the acquisition system,but the time spreading circuit is highly sensitive and vulnerable to the harsh environment of the well.A time spreading circuit calibration method is designed to correct the time spreading circuit and improve the random equivalent sampling measurement accuracy.(3)Data reconstruction system design for acquisition system.Using the high integration and reliability of FPGA,we design a ground-penetrating radar data reconstruction system based on random equivalent sampling to recover and process the echo signals acquired by ADC,and transfer the processed data to the upper computer.Finally,through the fabrication and debugging of each circuit,a random equivalent sampling system with real-time sampling rate of 100kSPS,equivalent sampling rate of 2GSPS and resolution of 12bit is finally realized,which realizes the acquisition and reconstruction of ground-penetrating radar echo signals.