海堤隐患雷达探测图像的小波处理及解释

Wavelet Processing and Its Explanation on the GPR Image of Hidden Seawall Hazard

海堤隐患雷达探测的成效有赖于雷达反射图像中隐患信息的准确识别。本文在介绍小波变换原理和MATLAB平台小波计算流程的基础上,阐述了某海堤隐患的雷达探测实例。各阶小波细节图变化趋势表明作为高频特征的隐患信息主要显示在低阶细节图上。从实际探测雷达图像的处理前后对比可见,小波分析方法可使图像中的隐患信息和分层信息更清晰、解释结果更准确。实际工程渗漏探测成果与注浆时反映情况符合较好,加固注浆过程中发现隐患地段的注浆量明显比其它地段要大,表明雷达探测成果较好地指导了防渗处理工作。

The effect of GPR exploration on hidden seawall hazard relies on the recognition of hazard information from GPR image. This paper describes the basic principle of wavelet transform( WT) and the computation flow based on MATLAB platform. The changes of the character on wavelet details image of different order show that the hidden hazard was a high frequency information,and mainly reflected in the lower order wavelet details map. The GPR images before and after processing by means of wavelet transform were compared. The results indicated that wavelet transform method was able to make the hazard information more obvious and the interpretation result more precise.The GPR image analysis result of practical case was consistent with the grouting result. The grouting quantity around the interpreted hazard location was more than that in other zones.