基于包络检波和STFT谱分析的探地雷达土壤分层信息识别

土壤分层信息,特别是表土层结构,对土地生产力具有重要影响,是评价土壤质量的一个重要指标。为了快速、准确地获取土壤分层信息,本文利用探地雷达对分层土壤进行了回波信号采集,并分别在时域和频域分析土壤层位置和层厚信息。首先在信号预处理的基础上,借助包络检波方法确定在土壤分层界面在时域上的位置;然后获取电磁波速度,得到土壤分层厚度。考虑到土壤介电常数与电磁波在土壤中传播速度的相关性,采用短时傅里叶变换方法（Short-time Fourier Transform,STFT）获取各土壤层时频域特征值,并利用回归分析建立特征值与介电常数之间的数学关系,实现对各土壤层的介电常数估算,从而计算出电磁波传播速度,进而确定土壤各层厚度。为验证算法的有效性,分别对理想模拟实验环境和农田环境进行了探地雷达实验,结果表明利用包络检波对探地雷达回波信息进行分析,土壤层检出率达到94.5%,借助STFT谱分析进行探地雷达回波速度估计,对于70 cm深度以上土层厚度计算误差大都保持在10%以下,但随着土壤深度的增加,误差变大。总体来说,本方法能有效识别浅层土壤的分层信息,可应用于实际生产中耕层厚度的估测。     

探地雷达在探测岩溶中的应用

介绍了探地雷达的基本原理,总结出雷达波在不同介质中的传播特性。并通过工程实例证明了探地雷达探测岩溶的可行性和有效性。     

水泥稳定粒料基层的压实度控制

道路水泥稳定粒料基层压实度控制的好坏,直接影响到整条道路的质量。文章介绍运用试验路法确定最大干密度,能有效地控制路面基层的压实度,使道路质量得到明显提高。     

探地雷达方法在特殊含油污水管道渗漏探测中的应用

基于含油污水管道内输送液体温度高、无压和检测区域面层为硬化混凝土的特点,对某厂区含油污水铸铁管道地下渗漏问题,利用探地雷达方法进行了探测.分析表明,污染物在地层中的扩散形态、污染物与孔隙水的导电性和综合介电常数是影响探测结果的主要因素,而这些因素又受到土层孔隙度、饱和度和污染物与孔隙水的相互作用影响,从而改变了土壤污染...     

探地雷达在地下考古遗存探测中的实验与应用

近年来,探地雷达被越来越多地应用于考古探查中。由于反演多解性问题的存在,雷达图像上的异常既可能是考古目标引起的,也可能是由于地下环境介质的不连续性引起的,所以探究不同类型的考古遗存在探地雷达图像上的典型异常响应,有助于准确识别雷达图像上的“真”异常,剔除一些“假”异常。首先,本文基于西北干旱-半干旱区文物埋藏环境,在河北省怀来县遥感综合试验站试验区设计实施了地下目标体探地雷达探测实验,分析了不同材质的小尺度目标体及夯土结构在探地雷达图像上的响应特征;然后,进一步将探地雷达应用于悬泉置遗址地下城墙基址的探测,对城墙在雷达图像上的响应特征进行了分析。实践表明,探地雷达技术在埋藏浅、小尺度、物性差异不大的考古探查中具有很好的效果,得到并解释了点状、线状、面状等不同考古目标体在探地雷达图像上的响应规律。     

探地雷达技术在岩溶探测中的应用

以黄河万家寨库区右岸岩溶探测为例,论述了雷达探测方法的技术及其工作原理,并结合岩溶探测实例,分析了岩溶地质现象所产生的雷达波场异常的空间展布特征,划定了该测区溶洞、溶蚀裂缝等岩溶地质异常的空间展布范围,验证结果表明:探地雷达技术在浅层岩溶探测中的有效性.     

让土地更有价值 让乡村更值向往——兰溪市聚焦“治、管、育”三个关键点全力推进土地整治

<正>近年来,兰溪市大力践行"绿水青山就是金山银山"理念,通过全域土地整治,有效发挥土地在推动乡村振兴战略中的支撑保障作用,促进耕地集中连片建设,提升耕地质量、优化耕地空间布局,实现土地增值、生态更优、乡村更美。近五年来,全市面上共有150个土地整治项目完成验收,其中,垦造耕地新增5940亩,旱改水新增4451亩。100个建设用地复垦项目验收,新增耕地面积达1703亩,其中水田755亩。2020年兰溪乡村全域土地综合整治与生态修复获浙江省政府正向激励。2021年灵洞乡洞源村全域土地综合整治与生态修复工程被评为省级精品工程。     

泰安市岩溶塌陷特征及探测方法研究

泰安市岩溶塌陷点主要集中在城区水源地与旧县水源地,对当地居民生产生活造成严重影响,急需查明已知塌陷点范围及隐伏溶洞位置,进行针对性治理。本文通过应用地质雷达、高密度电法与浅层地震,对已知土洞、隐伏溶洞及已知塌陷点进行探测,对东羊娄村与羊西村探测异常进行钻探验证,结果吻合较好。经分析研究认为:地质雷达能较好地分辨浅部土洞的位置;浅层地震探测深度较大,可以较准确地分辨覆盖层厚度与隐伏溶洞的空间位置,但对浅层土洞的分辨率较低;浅层土洞与隐伏溶洞在高密度电法电阻率断面图上有明显的反映,其分辨率不如地质雷达与浅层地震。根据不同物探方法的优点,结合研究区地质情况,提出了综合物探方法探测隐伏岩溶的最优化方案,以供参考。     

一切为了确保土地整治项目高质量——汝阳县国土资源局重拳砸向土地整治施工方

3月25日,汝阳县国土资源局土地整治指挥部重拳出击,出动大型机械,对该县正在实施的土地整治项目区内2个违规施工标段工程进行了强制拆除,共拆除田间道路120米、农用井2座,整改田间道路496米,并将2个标段违规施工情况向所有施工单位进行通报,警示其他施工单位引以为戒,高质量、高标准完成土地整治任务。目前,汝阳县正在实施2个土地综合整治项目。蔡店等4个乡(镇)土     

基于AHP模糊综合评价法的全域土地整治综合评价

全域土地综合整治是在目前农村土地综合整治的基础上,通过实施全域土地综合整治与生态修复工程,对农村生态、农业、建设空间进行全域优化布局,对“田水林路村”进行全要素综合整治,对高标准农田进行连片提质建设,对存量建设用地进行集中盘活,对美丽乡村和产业融合发展用地进行集约精准配置,对农村人居环境进行修复治理,逐步形成农田集中连片、建设用地集中集聚、空间形态高效节约的土地利用新格局。科学、有效、全面地推进全域土地整治工程,对开展全域土地整治工作具有很重要的意义。目前对工作考核评价通常做法是事先设计一套打分规则,考核时候根据规则对工作完成情况进行打分,最后分数汇总。这种考核评价方法比较简单,但在实施过程中存在不能全面考虑各要素之间的权重比例关系或者出现根据新情况简单调整考核指标,最后考核达不到预期效果。本文采用层次分析法和模糊数学综合评价法,通过构建全域整治评价指标,对台州市A县全域整治进行综合评价。     

工程物探在岩溶地区地质勘察中的应用——以费县电厂为例

结合费县电厂工程地质条件,运用高密度电阻率法和探地雷达勘察法,进行岩溶地区工程勘察,对2种方法的勘察结果进行比较分析,在此基础上进一步钻探验证。证实工程物探能迅速查明岩溶区的工程地质条件,勘察过程高效快速,达到地质勘察效果。最后针对岩溶区的拟建场地进行地基评价并提出地基处理方案。     

Measurements of sea ice thickness and its subice morphology analysis using ice-penetration radar in the Arctic Ocean

1　IntroductionSeaice ,asanimportantcomponentoftheArcticclimatesystem ,hasdrawnsignifi cantscientificinterest.Seaicethicknessanditsmorphologyhavedramaticimpactsono cean atmosphere iceinteractions(Wadhams 1 994;Barryetal.1 993 ;Dickson 1 999;PadhamsandNorman 2 0 0 0 ) ,whichdirectlyaffecttheexchangeprocessandspeedofheatandmassbetweentheoceanandtheatmosphere ,dominatethephysicalmechanicsfea turesofseaice ,andaffecttheseaicemovement&deformationaswellasicefreezing&meltingprocess(Hollandetal.1 99…     

Subsurface target recognition in Utopia Planitia of Mars by Tianwen-1 FP-SPR simulation

As a cold and dry planet, Mars contains water resources in the form of water ice, so that the electromagnetic waves can be transmitted to the deep underground to get the information of the topography and subsurface geological structure. Subsurface penetrating radar(SPR) can be widely used in deep space exploration for a long time because of its non-destructive detection mode and its working characteristics not limited by visible light. It is an important type of equipment for detecting the subsurface structure of planets. Orbiter radar is mainly used in Mars exploration. However, because of its low resolution, it is difficult to describe the near surface structure, so there is a lack of radar data which can reflect the shallow information. In this paper, a three-dimensional near surface model of Utopia Planitia on Mars is established. In order to make the simulation results more reasonable, the key factors such as topographic relief, subsurface rocks and water ice, and the variation of dielectric constant in different layers are taken into account. Then the full polarization forward modeling is carried out by using the three-dimensional finite-difference time-domain method. The acquired full polarimetric subsurface penetrating radar(FP-SPR) data with noise is preprocessed and further processed by Pauli decomposition. The underground reflection can be picked up more clearly from the Pauli decomposition results. This work is helpful to identify more details of subsurface structures and provides a reference for the measured data in the future.     

Identifying soil structure along headwater hillslopes using ground penetrating radar based technique

Soil structure plays an important role in understanding soil attributes as well as hydrological processes. Effective method to obtain high quality soil map is therefore important for both soil science research and soil work ability improvement. However, traditional method such as digging soil pits is destructive and time-consuming. In this study, the structure of headwater hillslopes from Hemuqiao catchment (Taihu Basin, China) have been analyzed both by indirect (ground penetrating radar, GPR) and direct (excavation or soil auger) methods. Four transects at different locations of hillslopes in the catchment were selected for GPR survey. Three of them (#1, #2, and #3) were excavated to obtain full-scale soil information for interpreting radar images. We found that the most distinct boundary that can be detected by GPR is the boundary between soil and underlain bedrock. In some cases (e.g., 8–17m in transect #2), in which the in situ soil was scarcely affected by colluvial process, different soil layers can be identified. This identification process utilized the sensitive of GPR to capture abrupt changes of soil characteristics in layer boundaries, e.g., surface organic layer (layer #1) and bamboo roots layer (layer #2, contain stone fragments), illuvial deposits layer (layer #3) and regolith layer (layer #4). However, in areas where stone fragments were irregularly distributed in the soil profile (highly affected by colluvial and/or fluvial process), it was possible to distinguish which part contains more stone fragments in soil profile on the basis of reflection density (transect #3). Transect #4 (unexcavated) was used to justify the GPR method for soil survey based on experiences from former transects. After that, O horizon thickness was compared by a hand auger. This work has demonstrated that GPR images can be of a potential data source for hydrological predictions.     

复频探地雷达在未爆弹探测中的应用

使用搭载200&400 MHz复合天线的LTD系列探地雷达,对埋设的未爆弹进行探测试验,并运用克希霍夫积分偏移法及三维插值算法对探地雷达数据进行三维成像。试验结果能准确地反映出浅埋未爆弹的位置信息,可指导排爆人员进行精确的开挖及排除。     

713天气雷达数字化系统

本文介绍了用IBM-PC/XT(AT)实现的天气雷达数字化系统的众多功能,分析了系统的工作原理。对于几个关键的技术问题——高速数据录取、软件数字视频积分、地物杂波抑制、座标变换及图象传输,分别给出了解决的方法和详尽的程序方框图。     

动态权重约束下的农村机耕路提取方法

宽度窄、路面材质与农田差异性低是农村机耕路的特点,也是导致现有模板匹配方法自动化程度低的主要因素.本文针对这一问题,提出动态权重约束下的农村机耕路提取方法.该方法首先通过改进多尺度线段方向直方图(Multi-Scale Line Segment Orientation Histogram,MLSOH)模型,对机耕路局部...     

Research on weak signal extraction and noise removal for GPR data based on principal component analysis

The ground penetrating radar( GPR) detection data is a wide band signal,always disturbed by some noise,such as ambient random noise and multiple reflection waves. The noise affects the target identification of underground medium seriously. A method based on principal component analysis( PCA) was proposed to extract the target signal and remove the uncorrelated noise. According to the correlation of signal,the authors get the eigenvalues and corresponding eigenvectors by decomposing the covariance matrix of GPR data and make linear transformation for the GPR data to get the principal components( PCs). The lower-order PCs stand for the strong correlated target signals of the raw data,and the higher-order ones present the uncorrelated noise.Thus the authors can extract the target signal and filter uncorrelated noise effectively by the PCA. This method was demonstrated on real ultra-wideband through-wall radar data and simulated GPR data. Both of the results show that the PCA method can effectively extract the GPR target signal and remove the uncorrelated noise.     

工程物探在S244省道K9+500～K10+100采空区的应用

山东省S244省道K9+500～K10+100段存在较严重的采空塌陷隐患,如何准确查清采空区的空间分布特征,对于道路的安全运营非常重要。根据以往类似工程经验,采用单一的物探方法,在准确探测采空塌陷形状、埋深等空间分布特征时存在较大难度,工程钻探可以比较直观的揭露采空塌陷的情况,但需要施工大量钻孔,在经济、时间等方面不可取,综合采用多种物探方法是一种准确有效的工作方法。以该工程为例,通过采用浅层地震反射波法和高密度电阻率法等工程物探方法,准确查明了该路段采空区空间分布特征,并通过比较直观的工程钻探对上述方法进行验证,效果良好。