提高线性调频连续波探地雷达厚度检测分辨率的信号处理方法

线性调频连续波探地雷达 (LFMCWGPR)用于检测路面厚度时要具有较高的垂向分辨率 ,而由于经典谱估计法固有的缺点 ,限制了分辨率的提高。利用Burg最大熵法和修正协方差法对探地雷达信号进行了处理 ,计算机模拟和室内实测信号处理的结果表明 ,这两种方法均能有效地提高LFMCW探地雷达的分辨率 ,使功率谱的主瓣变窄、旁瓣幅度降低。在对计算量无严格要求的情况下 ,修正协方差法的功率谱估计效果更好 ,它能克服使用Burg最大熵法出现的谱峰频率偏移和谱峰分裂的缺点。

Digital signal processing methods used for increasing thickness resolution of ground penetrating radar with linear frequency-modulated continuous wave

The ground penetrating radar with a linear frequency modulated continuous wave (LFMCW GPR) may have a high resolution when it is used to measure the concrete thickness of the highways or airports. However, the required thickness resolution could not be achieved using the classical power spectrum density estimating methods. The power spectrum density of the signal received by LFMCW GPR was treated using the Burg method and the modified covariance method. The simulation on computer and the experimental results show that these two methods can increase the resolution obviously and make main lobe peak narrower and side lobe peak lower. The comparison between the Burg method and the modified covariance method shows that the latter can reduce the frequency deviation and eliminate the spectrum split which occur easily for the former when the received signal is too short, or when there is an initial phase.