基于探地雷达的LNAPL污染土壤探测及成像算法研究

发布时间：2018-01-02 02:31

本文关键词：基于探地雷达的LNAPL污染土壤探测及成像算法研究　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着城市中加油站和储油设施的增加,由于各类因素导致部分石油类产品渗入地下环境的情况时有发生。而这些物质深入地下后将累积集聚,成为一个威胁周围环境和地下水资源的污染源。因此探测在这些地点发生的油污染的环保意义巨大。由于渗入地下的油污染有一定的流动性,传统的物理探测手段会使污染区域的地下结构发生改变,导致油污染再次迁移发生二次污染,因此,无损的电磁探测方法(如探地雷达)更适用于此类污染物的探测。传统的探地雷达对于这种介电常数较小且与周围环境混合的油污染物的分辨能力有限,成像结果较为一般。为了更好的获得地下的油污染信息,并对其进行较高分辨率的成像,本文引入了全极化探地雷达和相应的极化偏移算法技术。全极化探地雷达通过收发天线的不同极化组合,获取地下介质的极化散射特性,并用散射矩阵表示。不同的基矩阵反映不同类型的地下目标,为提高探地雷达的探测能力提供可能。极化偏移算法是将Pauli极化分解技术和Krichhoff偏移算法相结合开发出一种新算法。本文将极化偏移算法应用于轻非水相液体(LNAPL)污染土壤的探测研究。采用石英砂作为土壤,柴油作为LNAPL污染物,在实验室建立LNAPL污染土壤模型。然后利用全极化探地雷达系统对污染土壤进行探测。对预处理后的数据进行极化偏移成像后,LNAPL污染范围可以被清晰地识别。通过对包含极化特征的信息进行重构和成像,提高了探地雷达的探测能力。同时结合GPRmax正演模拟的污染模型结果进行验证确认,建立了对地下LNAPL污染的处理一套方法。
[Abstract]:With the increase of the city gas station and storage facilities, due to various factors lead to part of petroleum products into the underground environment occurs. And these substances will accumulate deep underground after agglomeration, become a source of pollution is a threat to the surrounding environment and groundwater resources. So the detection occurred in these locations of oil pollution in environmental protection great. Because of the underground oil pollution into a certain fluidity, the traditional physical detection method will make the underground structure pollution area change, cause the oil pollution again transfer two pollution, therefore, non-destructive method of electromagnetic detection (such as GPR) detection is more suitable for such pollutants. The traditional ground the radar for the smaller dielectric constant and the surrounding environment and oil mixed dye resolution imaging results are generally limited. In order to get better underground oil pollution information High resolution imaging, and on it, this paper introduces the radar polarization technology and corresponding algorithm of polarimetric detection. Different polarization combinations of polarimetric GPR with antenna, obtain the polarization scattering characteristics of underground medium, and is represented by the scattering matrix. Matrix reflects the different underground objects of different types. May be provided to improve the detection capability of GPR. The polarization offset algorithm is Pauli decomposition technique and Krichhoff migration algorithm is developed combining a new algorithm. This algorithm is applied to the polarization of light non-aqueous phase liquid (LNAPL) detection of contaminated soil. As the soil using quartz sand, diesel as LNAPL pollutants the establishment of LNAPL, soil pollution model in the laboratory. And then use the full polarimetric GPR system to detect contaminated soil. The preprocessed data for polarization imaging After the LNAPL pollution range can be clearly identified. Reconstruction and imaging based on polarization characteristics contains information, improve the detection capability of GPR. Combined with the model of pollution GPRmax simulation results verify, established a set of methods for processing LNAPL underground pollution.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P631.3;X833

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