共查询到20条相似文献，搜索用时 31 毫秒
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Ground penetrating radar (GPR) is an effective geophysical method for environmental and engineering exploration. However, significant background interference occurs around most work sites, which increases the difficulty of analyzing and interpreting GPR profiles. For time-distance profile analyses, more accurate results can be obtained using the instantaneous parameters of the analytic signals. In this study, these instantaneous parameters are extracted and compared using 1D model waveform and 2D model strong interference profiles. The results show that the instantaneous amplitude gradient effectively reflects the model information, even under strong interference. The instantaneous amplitude gradient is applied to GPR survey data from a study site, and the results indicate that the technique reflects the underground structure information of the survey area. Drilling verification further confirms that the instantaneous amplitude gradient accurately reflects the underground structure information. 相似文献
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Ground penetrating radar (GPR) is widely used for non-invasive examination of man-made structures, especially to determine the depth of pipes buried underground. Unfortunately, shallower objects may obscure GPR raw data that is reflected from deeper ones. This study introduces a signal processing technique, called the discrete wavelet transform (DWT), to filter and enhance the GPR raw data in order to obtain higher quality profile images. Laboratory experiments were conducted and the locations of buried pipes under different conditions were analyzed. The buried pipes were made of plastic and metal, and both single and two parallel horizontal pipes are discussed. The experimental results indicate that the DWT profiles can provide more information than the traditional GPR profile. The images of the diameter and position of pipes, even two pipes of different materials and in horizontal alignment, can be enhanced by using the DWT profile. 相似文献
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不同地质雷达测量参数对数据采集效果的影响 总被引：4，自引：0，他引：4
地质雷达探测技术是近年来适应快速、准确、无损的探测地下障碍物及对地下工程质量评价而迅速发展的方法技术。而这门方法的一个根本环节就是数据采集。本文通过结合工程实例来探讨不同的地质雷达测量参数对数据采集效果的影响。 相似文献
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Ground Penetrating Radar (GPR) investigation tools are increasingly used for real-time detection of underground utilities. Background noise is an annoying problem, because it sometimes masks the reflection from objects of interest. This study introduces an efficient background removal algorithm, which is so simple that it can be incorporated into GPR logging devices. The algorithm is based on the recently published outliers-out algorithm for stacking seismic data. Experiments conducted on both synthetic and field GPR data show that proposed background removal algorithm yields much better results than the commonly used average trace subtraction algorithm in a relatively comparable computational time. 相似文献
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Arabian Journal of Geosciences - The incessant expansion of megacities is usually associated with the extension of different underground utilities underneath these cities. In recent years, the need... 相似文献
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混凝土体内钢筋位置检测实例：高频地质雷达应用效果 总被引：4，自引：0，他引：4
通过高频雷达对混凝土体内钢筋位置检测的实例,展示其作为一种地下不明障碍物进行无损检测或评价地下工程质量的高新技术,具有良好的应用效果。 相似文献
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针对探地雷达(Ground Penetrating Radar,GPR)信号信噪比低、背景杂波强,事先对探测目标的信息所知甚少,近乎处于“盲”状态,因而实际处理难度大等实际问题,提出了将独立分量分析(In-dependent Component Analysis,ICA)这种盲信号处理技术应用于GPR信号处理,并利用ICA中的Fast-ICA算法,对ICA法在GPR信号处理中的应用进行了初步探索,实现了GPR信号中弱目标信号和强背景杂波的有效分离,并初步解决了对所分离目标信号的正确排序,以及由ICA方法本身带来的所分离目标独立分量信号符号的不确定性等问题,使GPR信号信噪比大幅提高,从而使GPR的目标检测性能也得以显著改善。在对诸如地雷、地下管线等局部目标的时域有限差分法(Finite-dif-ference Time-domain,FDTD)、仿真GPR数据和室外试验观测GPR数据进行ICA处理后,都取得了理想的结果。 相似文献
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阻抗反演是利用波阻抗与介电常数关系开展地下介质参数估计的重要技术,在探地雷达以及叠后地震资料解释中具有广泛的应用。常规阻抗反演需要钻孔或测井曲线作为约束项,约束项信息直接影响阻抗反演的估计精度。在缺少钻孔数据的实际应用中,如何开展探地雷达阻抗反演是该方法研究的重要内容之一。基于上述问题,本文提出了基于速度分析的探地雷达阻抗反演方法。其基本思想是基于多偏移距雷达数据开展速度谱分析和Dix反演,以获得不同深度的速度信息作为阻抗反演的约束项;同时,采用K-means方法自动拾取速度谱信息,大大降低了常规人工拾取误差,提高了计算效率。通过典型随机土壤介质模型,验证了本文方法在无钻孔条件下仍然可以获得较好的介电常数估计结果,并测试噪声适应能力强。最后通过美国密歇根州Wurtsmith AFB,in Oscoda区域的探地雷达数据测试了本文提出方法在探地雷达实测数据参数估计中具有较好的应用效果。 相似文献
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探地雷达是利用超高频脉冲电磁波探测地下介质分布的一种浅层地球物理勘探方法,探地雷达超高频、宽频带脉冲电磁波在地下有耗介质中的衰减特性是一个十分复杂的过程。本文从电磁波传播的麦克斯韦方程出发,较为系统地研究和分析了雷达脉冲电磁波在有耗介质中传播的衰减特性,对研究雷达脉冲电磁波在地下有耗介质中的传播机制有指导意义。 相似文献
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探地雷达因其快速、准确、无损、高分辨率等优势而被广泛应用于冰川学领域。以天山托木尔峰青冰滩72号冰川为例,着重介绍了探地雷达在冰川厚度及冰下地形探测中的应用。通过对雷达图像的处理和解译,获取了高精度的冰川厚度数据,恢复了冰下地形,计算了冰储量,并分析了冰川厚度变化对气候变化的响应。结果表明:冰舌厚度为0～148 m;冰储量为0.055 860 km3,折合成水为0.050 274 km3。近50年来,该冰川呈现强烈消融,与冰川区气温快速上升有直接关系,雷达探测为研究此响应机制提供了定量化的科学依据。 相似文献
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探地雷达(GPR)噪声信号通常具有非稳态、非线性特征,为去除这些噪声提高GPR图像解译的准确性,对利用HHT方法去噪进行了研究。首先阐述HHT的基本理论,然后通过对探地雷达数值模拟信号中噪声的去除验证基于HHT方法的可行性,最后将该方法用于探地雷达隧道地质超前预报的数据处理中。通过研究表明:该方法可以用于探地雷达信号的去噪,通过Hilbert变换得到三特征参数图像与EMD分解后合成图像进行对比验证,从而达到提高GPR信号解译精度的目的。 相似文献
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In the current research, the ground-penetrating radar (GPR) method has been employed to identify physical and geometrical parameters of buried cylindrical structures using the pattern recognition approach. To achieve this goal, the well-established mathematical relationships between geometrical parameters of cylindrical target (radius, burial depth, and horizontal location) and the associated GPR hyperbolic response characteristics are employed using the template matching method. In order to validate the applicability of the template matching method in providing estimates of such parameters, the method is first examined on GPR responses of synthetic models with known geometrical parameters followed by applying on real data using two different similarity criteria including 2-D spatial convolution and normalized cross correlation in the wave number domain. In the first step, the GPR responses of 71 synthetic models encompassing one, two, and three horizontal cylinders were produced using the improved 2-D finite difference in frequency domain. Then, appropriate preprocessing sequences to reduce random noise caused by forward modeling were applied on synthetic data. The proposed algorithm applied on several synthetic model responses could estimate the known geometrical parameters of the buried cylinders with acceptable accuracy (maximum error of 15%). The template matching algorithm was also used to extract geometrical parameters of water and wastewater pipes buried in Imam Hossein Square, Isfahan city, as real GPR data. Depending on environmental conditions and subsurface host formation, the real GPR data normally contain a variety of noises; therefore, a series of appropriate objective preprocessing and processing stages were designed in order to apply on real GPR images before deploying template matching algorithm. The applicability of the template matching algorithm on real data and validity of the estimated parameters were proved based on assessing the accuracy of the estimated geometrical parameters of respective pipes through GPR response versus the measured parameters. The proposed algorithm was designed in such a way that all steps of estimating geometrical parameters of buried cylindrical targets are automatically carried out. 相似文献
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用高阶统计量方法对探地雷达数据进行处理,基本思路是采用信号识别与检测中的高阶统计量参数,对不同模型的探地雷达数据记录进行处理与重构,结果表明不同模型具有不同阶数的高阶统计量特征。模型实验与实际应用都表明,高阶统计量对压制背景噪声和多次反射波有较好的效果。 相似文献