Ground Penetrating Radar (GPR) attribute analysis for archaeological prospection

We evaluate the applicability and the effectiveness of the GPR attribute analysis for archaeological purposes and we test the attribute analysis on GPR data obtained in the river harbor area of the Aquileia Archaeological Park, NE Italy, where cultural heritage of the Roman imperial period is buried at different depths beneath a silty loam layer at an average depth not greater than 3–4 m. A multi-attribute approach is used to characterize the subsurface through several attribute categories, including instantaneous, section and volume attributes applied to quantities related not only to the reflection amplitude, but also to frequency and phase or other more complex parameters. The results allow the identification of different buried archaeological remains, from brick walls to isolated stone chunks also in a very complex environment characterized by several interconnected or superimposed archaeological remains.     

3D GPR measurements for archaeological application with interpretation aided by numerical modelling

The paper presents the results of georadar investigations carried out in the area of the monastery at Tyniec near Cracow for archaeological purposes. The georadar profiles were designed on the abbey courtyard in a regular grid, which covered the area of the buildings that currently do not exist. The aim of the measurements was to produce a 3D visualization of former buildings’ foundation. The results of the geophysical measurements were correlated with the information obtained from archaeological investigations. The georadar surveys confirmed the location of foundations documented by archeologists and new underground structures were discovered. To aid the interpretation, numerical modelling of the electromagnetic wave field was performed. Computer modelling allowed to determine the kind and condition of underground structures.     

High resolution 3D ERT to help GPR data interpretation for researching archaeological items in a geologically complex subsurface

Muro Leccese (Lecce) contains one the most important Messapian archaeological sites in southern Italy.The archaeological interest of the site arises from the discovery of the remains of Messapian walls, tombs, roads, etc. (4th–2nd centuries BC) in the neighbourhood. The archaeological remains were found at about 0.3 m depth.At present the site belongs to the municipality, which intends to build a new sewer network through it. The risk of destroying potentially interesting ancient archaeological structures during the works prompted an archaeological survey of the area. The relatively large dimensions of the area (almost 10,000 m²), together with time and cost constraints, made it necessary to use geophysical investigations as a faster means to ascertain the presence of archaeological items. Since the most important targets were expected to be located at a soil depth of about 0.3 m, a ground-penetrating radar (GPR) survey was carried out in an area located near the archaeological excavations. Unfortunately the geological complexity did not allow an easy interpretation of the GPR data.Therefore a 3D electrical resistivity tomography (ERT) scan was conducted in order to resolve these interpretation problems.A three-way comparison of the results of the dense ERT measurements parallel to the x axis, the results of the measurements parallel to the y axis and the combined results was performed.Subsequently the synthetic model approach was used to provide a better characterization of the resistivity anomalies visible on the ERT field data.The 3D inversion results clearly illustrate the capability to resolve in view of quality 3D structures of archaeological interest. According to the presented data the inversion models along one direction (x or y) seems to be adequate in reconstructing the subsurface structures.Naturally field data produce good quality reconstructions of the archaeological features only if the x-line and y-line measurements are considered together. Despite the increased computational time required by the 3D acquisition and 3D inversion schemes, good quality results can be produced.     

3D geoelectric tomography and archaeological applications1

Following a previous paper in which the principles of a 3D ground-surface tomographic processing of self-potential data were established, we extend the method to active source geoelectric surveying. The main purpose of the new tomographic approach is to obtain a physical image reconstruction of the induced electric charges distributed over buried resistivity discontinuities. The information is produced in a probabilistic sense, as the mathematical formulation underlying the method treats only the intrinsic physical nature of the generated electric field underground and the method of its ground-surface detection, independently of the geometry of the unknown structures. In practice, a 3D tomography is realized by cross-correlating a set of distributed electric-field ground-surface data with a scanning function, representing a unit positive point charge located anywhere in the lower half-space. The resolution of the method is tested on the synthetic response of a 3D structural simulation of an archaeological target, consisting of an infinitely resistive prismatic body immersed in a half-space, including surface inhomogeneities and layering. Finally, the field response of a 3D structure consisting of a hypogeal dromos-chamber tomb inside the Sabine Necropolis at Colle del Forno, close to Rome, is presented and discussed.     

地震属性技术在四维地震监测中的应用

四维地震(4D seimic)主要是指利用重复三维地震测量资料进行油藏动态监测。在油田开发过程中,由于储层特性变化所引起的地震振幅异常、频率变化以及反射同相轴下拖现象等均可作为注蒸汽波及范围四维地震监测的良好识别标志。由于叠后地震资料中常常存在动校正速度不准、动校正拉伸畸变、剩余静校正误差、以及CDP道集中各道波形的差异性等多方面的问题,这会对叠后地震资料所反映出的四维地震异常特性产生影响,造成解释结果的差异性和不确定性。为此,本文尝试开展叠前地震属性反演研究,利用瞬时频率、瞬时频率梯度、能量衰减85%时的频率、最大振幅频率、最大振幅、总能量等多种衰减属性的叠前剖面及其差值剖面来定性解释四维地震实验区的注入蒸汽在剖面上的反映。     

大港油田三维可视化解释技术的应用实例分析

三维可视化解释技术是一项全新的地震解释技术,与传统的地震资料解释有着本质的不同,它是从三维可视化显示出发,以地质体或三维研究区块为单元,采用点、线、面和体相结合的数据体空间可视化解释。该技术结合相干体技术可进行复杂断层的解释与组合;应用空间域层位自动追踪技术能够准确落实构造形态;采用目标雕刻技术,利用反演数据体可实现立体透视岩性体的空间展布及厚度趋势。将该技术应用在大港油田官西地区复杂断块构造解释和歧南西斜坡隐蔽油气藏储层预测两项实际工作中,取得了良好效果,表明可视化解释技术在石油勘探中具有广阔的应用前景,是提高勘探效率和勘探成功率的有效技术手段。     

Application examples of 3D visual interpretation technology in Dagang Oilfield

3D visualization technology is a new seismic interpretation technology that is completely different from traditional seismic data interpretation technologies. This method takes geologic bodies or any 3D region of interest as a unit and integrates the points, lines, and planes of the bodies to make a 3D visual interpretation. This technology can be integrated with the coherence technique to interpret complex faults. Spatial domain automatic horizon tracing can accurately determine structural features. Target sculpting can determine the spatial dimensions and depth extent of perspective 3D lithology bodies using inversion data. I applied this technology to the interpretation of the complex block structures in the Guanxi area of Dagang Oilfield and the prediction of subtle reservoirs in the western slope of the Qinan sag with good results. This study indicated that the visual interpretation technology can be widely and effectively applied in oil field development and to improve the exploration success ratio.     

探地雷达属性技术进展

探地雷达属性技术经过近十年的发展,其重要性已得到众多学者的逐渐认可,应用领域也越来越广泛,为了使该技术能进一步的深入发展,对其进行较全面的总结、评价和分析十分必要.本文通过对国内外资料的收集和分析,总结探地雷达属性技术中的成果,回顾了其发展历史,列举了目前常用的属性,阐述了具体研究方法,介绍了该技术应用领域,并对今后的发展进行了展望,认为探地震达属性技术拥有良好的应用前景.     

Photographing layer thicknesses and discontinuities in a marble quarry with 3D GPR visualisation

An important problem of marble-quarry management is assessing the quality and the homogeneity of quarry blocks before excavation. In this study, we decided to image the limestone, which we studied in a marble quarry, in terms of layer thickness, discontinuities and cavities using the ground-penetrating-radar (GPR) method. The method was successfully applied to detect and map the fractures with the cavities in a marble layer according to depth in the Ankara City Polatli Town (Turkey) region, which represents upper Miocene–Pliocene lacustrine carbonate rocks.This paper is based on interactive transparent 3D visualisation of the 2D GPR profiles to determine changes in layer thickness and discontinuities. In addition, this paper indicates the importance of the appropriate opacity-function construction to obtain transparent 3D visualisation. Firstly we acquired and processed parallel 2D GPR profile data, then we assigned two different amplitude–colour ranges using a limited number of colours to determine the layer thickness and its discontinuities separately. We obtained a 3D volume using parallel 2D GPR data and displayed a limited amplitude range by arranging an opacity function. Therefore, we obtained transparent 3D blocks for thickness and discontinuities, and we formulated an interactive 3D display to image the horizontal, vertical and inclined discontinuities and their directions in the x–y plane versus depth. The GPR results were compared with the petrographical investigation on the basis of textural and mineralogical compositions. The vesicular textures within carbonate platform were supported by the GPR results.     

路用探地雷达的应用技术研究进展

有效、无损、快捷、简便是公路检测技术发展的方向，当前国内外先进的浅层勘探技术——路用探地雷达检测，以其无损、快捷以及浅层高分辨率的优势被迅速应用于公路检测。本文对近年来路用探地雷达技术的发展及应用情况进行了介绍，详细分析了探地雷达的工作原理、系统组成结构。就探地雷达在公路建设、维护过程中的应用情况进行了系统总结。     

探地雷达在探测隐伏活动断层中的应用

以东昆仑断裂带东部采用探地雷达探测隐伏活动断层为例。 在浅覆盖区, 利用合理的采集参数和数据处理流程; 雷达剖面图像能够清晰地显示出隐伏断层的形态特征和岩土分层; 结合沉积序列, 可以分析和评价断层的活动性。 实验证明, 探地雷达是一种有效探测浅覆盖区隐伏活动断层的方法。     

基于地震属性各向异性的火山机构识别技术

本文通过对地震资料的分方位处理,分别提取各方位的地震属性,筛选出最具代表性的地震属性,通过属性方位椭圆拟合,求取该属性椭圆的"扁率",用椭圆"扁率"来表征储层的各向异性,并在此基础上识别火山机构.本文提出了基于地震属性各向异性的火山机构识别方法,利用叠前地震资料分方位提取地震属性,并对方位地震属性值进行椭圆拟合,利用椭圆扁率来表征各向异性的大小,并基于此来识别火山机构.本文对方法的流程进行了详细阐述,对方法的适用条件作了简要的说明,并用实际地震资料进行了效果检验,对检验结果进行了对比分析,取得了较好的效果.     

EM and GPR investigations of contaminant spread around the Hoc Mon waste site,Vietnam

This paper is presenting the results from near-surface geophysical surveys near the waste site of Hoc Mon in southern Vietnam where leachate contamination has been recognized at the surface. Using EM and GPR surveys, we were able to determine the lateral extent of a contaminated area of high electrical conductivity and have identified channels that concentrate the contaminant flow. The simple relationship between the electrical resistivity and the leachate concentration is suggested and estimated the in situ leachate concentration from the inversion of the EM data; values are as high as 40%. Thanks to a permeability barrier leachate flow is confined to the shallow subsurface, making it easier to apply possible site remediation projects.     

基于地震属性融合技术的火山通道识别研究

长岭龙凤山火山岩为多机构、多期次喷发叠合分布的一套火山岩地层,火山通道识别是成藏分析和油气运移等研究工作的基础,同时也影响储量计算和开发井的部署.针对深层地震资料品质较差,且难以对火山通道进行准确刻画的问题,开展针对火山通道的地震属性优选.该地区火山岩具有"低频强振幅"的特点,通过地震属性优选,提取10 Hz单频体、纹...     

地球物理信号处理技术的研究及进展

从数字信号处理的原理、应用、发展过程及前景等方面对数字信号处理技术作了概述，重点总结了应用地球物理方法中和的信号处理方法和技术。对探地雷达技术中常用的数据处理技术作了详细阐述，并简要介绍了作者研制的信号处理软件。     

基于弹性波CT与GPR的岩体综合病害识别及三维地质建模

本文以地铁深基坑岩体边坡为研究对象,采用弹性波CT初步判断基坑岩体病害的类型及空间分布并辅以地质雷达进行验证;进而用分水岭算法分析弹性波CT获得的波速分布,以提取病害处的细部声速变化,圈定病害范围;在此基础上,以弹性波CT三维空间波速数据库的坐标信息为基础,结合分水岭算法得到的空间坐标信息获得建模数据库,导入GOCAD...     

三维地震属性技术在湖区的应用效果

微山湖湖区表层地震地质条件十分复杂,芦苇丛生,三维地震勘探野外数据采集采用自行研制的钻井平台加套管护壁的成孔工艺,沼泽检波器加上加长尾椎,提高了检波器的耦合效果,获取了高信噪比的三维地震数据。资料解释应用了三维可视化、相干数据体、地震属性技术进行三维构造精细化解释,明显提高了地震解释识别地下小地质构造及地震异常体的能力,它完善和发展了三维高分辨率地震勘探技术,扩大了地震勘探的应用范围,为解决煤矿开采阶段所遇到的构造、煤层等地质问题提供了一种综合应用的解释方法,在湖区的勘探开发中,取得了明显的地震地质效果。     

CT扫描技术在岩心三维重建中的应用

岩石是具有复杂空间几何分布和不同孔隙尺寸的多孔介质,复杂的孔隙结构不仅影响着岩石的物理性质,同时也为石油天然气等能源的开采带来困难。本文介绍一种基于三维数字岩心的新方法CDPRM,CDPRM利用CT扫描高精度、高分辨率等优点构建类似真实岩心的三维模型,利用3-matic软件将数字岩心转化为数据模型STL文件,导入3D打印机打印岩样并用于实验,同时用HYPERMESH软件对三维孔隙模型进行网格划分并导入有限元软件进行数值模拟。以砂岩为例,对CDPRM的数值模拟应用进行了初步探索。最后对CDPRM的发展做了展望,认为3D打印制作材料混合使用和其他技术（如：光弹性技术）相结合应用将是主要研究方向。     

ActiveX技术在三维地震资料可视化中的应用

文章在介绍了三维地震资料可视化原理的基础上,利用SGI的OpenInventor实现了：(1)三维地震数据体的切片(主测线、联络测线、水平方向)显示;(2)数据体切片的移动、缩放、旋转;(3)视觉效果可以选择,可以调节数据体的透明度、颜色;(4)地震“电影”的功能.结合ActiveX技术,将以上功能实现封装为ActiveX控件,嵌入到PowerPoint中,实现了地质汇报中三维地震资料的动态显示与控制.     

GPS在探地雷达探测城市道路塌陷隐患中的应用研究

在城市道路塌陷隐患探测中,回溯定位探地雷达剖面中病害异常的现场位置是对其进行复测验证及处治修复的关键.测距轮属于相对定位技术,具有难以消除的累积误差,且探地雷达剖面越长,其累积误差越大,回溯定位病害异常的现场位置越难,而GPS测量定位属于绝对坐标定位技术,没有累积误差,但在复杂的城市环境中,其干扰因素较多,测量误差较大,影响病害现场回溯定位的精度和准确性.联合采用测距轮和GPS对探地雷达进行跟踪测量定位,测距轮按照固定道间距触发探地雷达和GPS同步采集、同步存储,使每一道探地雷达数据与GPS经纬度坐标一一对应、彼此关联、相互追溯;通过绘制GPS路径轨迹,直观形象展示探地雷达实测剖面的测线位置及其工作量完成情况;采用移动平均法对GPS原始数据进行平滑去噪处理,修正测量误差,消除局部突变点,使GPS路径轨迹更平顺,更符合探地雷达检测车实际行驶的路径轨迹,由此计算得到的路径轨迹长度稳定性更高、一致性更好,更符合探地雷达实测剖面长度,同时可以有效提高病害现场回溯定位的精度,显著加快病害异常点加密复测验证工作进度.