基于FPGA冲击脉冲探地雷达信号采集系统的研究

发布时间：2018-04-10 21:07

本文选题：冲击脉冲探地雷达 + FPGA　；参考：《沈阳航空航天大学》2015年硕士论文

【摘要】：探地雷达是一种利用高频电磁脉冲对地下物质进行信息获取的探测方法，根据接收到回波信号的变化信息，对地下介质的结构、位置、形态进行合理推断。冲击脉冲探地雷达以其速度快、分辨率高、频带宽、无损性等优点成为当前市场中应用最为广泛的探测设备，其回波信号携带大量的地下信息，获取的信息越多，所探测未知区域越清晰。因此，对冲击脉冲探地雷达采集系统的研究具有重要的价值和意义。本文首先介绍了冲击脉冲探地雷达的工作原理，根据其脉冲信号的特性和参数的要求对冲击脉冲探地雷达的结构进行系统研究，在此基础上利用高速ADC芯片设计一种对冲击脉冲探地雷达回波信号的采集方案。采集系统以FPGA为核心，，控制系统中各部分工作，对于高速信号要以差分的方式进行采集，以保证信号的稳定性。采集到的高速数据利用FPGA内部丰富的RAM块资源自定制FIFO进行多级缓存降速处理，最终以低于采样频率几倍的速率通过USB总线传至上位机，以便于后续的数据处理工作。系统利用FPGA及USB接口，使数据采集达到实时性的效果。本文研究的是冲击脉冲探地雷达信号采集系统，其核心的部分是利用FPGA控制高速ADC采集和数据的缓存存储。系统通过对硬件电路和软件部分的调试，得到了FPGA设计部分正确的仿真，实现了对占空比较低的窄脉冲信号和高频正弦信号的采集测试以及原始波形和频谱的恢复。本系统方案设计合理，能够实现对冲击脉冲探地雷达回波信号的正确采集与存储。
[Abstract]:Ground penetrating radar (GPR) is a method to detect the information of underground material by using high frequency electromagnetic pulse. According to the change information of echo signal, the structure, position and shape of underground medium are reasonably inferred.Impulse GPR has become the most widely used detection equipment in the current market because of its high speed, high resolution, frequency bandwidth, nondestructive and so on. Its echo signal carries a lot of underground information, and the more information it gets, the more information it acquires.The clearer the unknown region is detected.Therefore, the research of impulse GPR acquisition system is of great value and significance.In this paper, the working principle of Impulse GPR is introduced, and the structure of Impulse GPR is systematically studied according to the characteristics and parameters of pulse signal.On the basis of this, a high speed ADC chip is used to design a method for collecting the echo signal of impulse ground penetrating radar.The acquisition system takes FPGA as the core, and the control system works in every part of the system. The high speed signal should be collected in a differential way to ensure the stability of the signal.The collected high speed data is processed by using the rich RAM block resource of FPGA to customize the FIFO for multilevel buffer speed reduction, and finally it is transmitted to the host computer by USB bus at a rate several times lower than the sampling frequency, so as to facilitate the subsequent data processing.The system makes use of FPGA and USB interface to achieve real-time effect of data acquisition.In this paper, the Impulse GPR signal acquisition system is studied, the core of which is to use FPGA to control high-speed ADC acquisition and data cache storage.Through debugging the hardware circuit and software, the FPGA design part is simulated correctly, and the acquisition and test of the narrow pulse signal and the high frequency sinusoidal signal with low duty cycle are realized, as well as the original waveform and the recovery of the frequency spectrum.The scheme of this system is reasonable and can realize the correct acquisition and storage of the echo signal of Impulse GPR.
【学位授予单位】：沈阳航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN791;TN957.51

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