一种改进的滤除探地雷达直耦波的算法

An improved filter algorithm of direct arrive wave for GPR

探地雷达具有高效、快速、无损、抗干扰能力强等优点,成为浅层勘探的有力工具.雷达探测的准确性与资料处理有重要关系,处理技术将直接影响探测结果的准确性和可信度,本文主要对探地雷达信号直耦波的滤波处理技术进行了研究.典型的规则噪声直耦波具有强相关、能量强、呈水平状、出现早等特点,传统的滤波方法是采用KL变换.KL变换是对记录道在整个时间轴上的分析,不具备局部时间范围内的分析能力,KL变换滤波在提高剖面横向分辨率的同时,在垂向上会出现干扰,降低垂向分辨率.如果在KL变换基础上结合小波分时分频的特点,可以很好地解决上述问题.因此针对滤除直耦波及水平波,本文提出了小波域KL变换法,经模型实验与实际应用验证了改进后的滤波不仅横向分辨率较KL变换有明显的提高,而且垂向上也克服了KL变换的缺点,没有产生干扰波.

Ground penetrating radar is a geophysical exploration method which detects the underground structure and characteristics. Because of the advantages such as high efficiency, quick speed, undamaged, and strong antb noise features, it has been applied to every aspect in engineering domain, and it is a powerful tool of shallow layer exploration. Precision of GPR exploration has important connect with data processing, processing technique which is not fit is negative to detecting result directly. With information technique and electron technique rapid development, collecting data is more various, traditional GPR processing technique is not obviously sufficient. This thesis studied the filter techniques of direct arrive wave for GPR. Because of the features of direct arrive wave that has strong correlation, strong power, horizontal, first arrival, to this traditional filter method is KL transform, it is found that KL transform is only description to information of record trace＇ s whole time axis after study KL transform＇ s theory, not to time axis＇ s the information, namely while KL transform filter has improved image＇s horizontal resolution, there is interference in vertical resolution to reduce of vertical resolution. Combining with features of wavelet＇s parted time and frequency, it is better to resolve part questions. Therefore, this thesis bring forward wavelet＇s KL transform to filter direct arrive and horizontal wave, this algorithm is not only more improve horizontal resolution than KL transform, but also overcome disadvantage of KL transform in vertical axis that is not interference.