基于TerrSolid对机载雷达DEM重提取方法研究     

王瑚  周光耀  周海龙 《测绘与空间地理信息》2020,(3):127-130

DEM的提取是激光雷达数据采集的重要用途之一,但由于目前算法的局限性,无法高精度地自动分类,如何在算法分类的基础上重新进行人工分类,以一定的原则和标准进行重提取从而得到更高精度的DEM,仍然是专业领域的一大难题。本文对某.LAS数据重提取,极大提高了其DEM的精度,为今后相关单位和个人使用TerrSolid软件对机载雷达DEM重提取提供一些经验。  相似文献   

利用GLAS激光测高数据评估DSM产品质量及精度优化   总被引：2，自引：0，他引：2  

胡柳茹  唐新明  李国元  付冬暇  窦显辉  赵世湖 《测绘通报》2019,(11):39-43

提出了一种利用卫星激光测高数据直接优化提升数字表面模型（DSM）产品精度的方法。选取境外中亚地区的资源三号DSM开展试验，通过采用多准则约束方法提取激光高程控制点，分别利用偏度、中值、线性、二次多项式等进行DSM误差修正，发现4种模型均能有效消除DSM系统误差，其中基于二次多项式的方法更适用于平地和丘陵地貌，线性模型更适用于高山地貌。试验验证了采用卫星激光测高数据优化境外DSM技术流程的可行性，最终可提高DSM的绝对高程精度。  相似文献   

Novel Hybrid Integration Approach of Bagging-Based Fisher’s Linear Discriminant Function for Groundwater Potential Analysis     

Chen  Wei  Pradhan  Biswajeet  Li  Shaojun  Shahabi  Himan  Rizeei  Hossein Mojaddadi  Hou  Enke  Wang  Shengquan 《Natural Resources Research》2019,28(4):1239-1258

Natural Resources Research - Groundwater is a vital water source in the rural and urban areas of developing and developed nations. In this study, a novel hybrid integration approach of...  相似文献   

基于正交匹配追踪的声层析方法   总被引：2，自引：0，他引：2  

李倩倩  史娟  李整林  罗宇  阳凡林  张凯 《海洋学报(英文版)》2019,38(11):149-157

声速剖面的变化会对声传播产生较大的影响，经验正交函数模型经常用来实现对声速剖面数据的简化描述。然而在内波、湍流等海水不均匀性存在时，这种正则化操作会造成声速重构精度的大幅降低。本文利用字典学习生成声速剖面的非正交原子，在稀疏编码时采用正交匹配追踪（OMP，Orthogonal Matching Pursuit）算法，更新字典则使用KSVD （Kernel Singular Value Decomposition）的字典更新算法。由于字典学习不需要强制使用正交条件，对于训练数据更加灵活，从而可以使用少数的原子组合达到更高的重构精度。利用一次浅海声学实验多次测量的声速剖面研究了海水声速剖面的经验正交函数表示和字典学习，研究表明：相比于正交函数表示，学习字典可以利用少数原子（甚至一个原子）更好的解释声速剖面扰动。字典学习可以提高声速剖面的稀疏性，从而提高声速剖面的反演精度。  相似文献   

空地技术结合地形图测图方法研究     

方秋生  王宵雷  刘如飞  马新江 《测绘与空间地理信息》2020,(3):37-40

车载移动测量系统可以快速、高精度地对测区进行三维激光扫描,但是因地物遮挡、视角限制,使得点云数据存在缺失;无人机航测具有高效率、高灵活性和低成本等优势,但是稳定性差,受天气影像严重,易导致影像不清晰或精度低。无人机航测技术可以弥补车载移动测量技术的采集盲区,后者可以发挥高精度的优点,二者技术联合应用,将极大提高测绘精度及生产效率。本文以某小区为例,进行了相关方法实验,对建筑物顶部或植被茂密处等扫描盲区,采用无人机航测补测,通过高精度激光点云对航摄影像进行纠正匹配,综合利用激光点云与航摄影像进行大比例尺测图。  相似文献   

三维地理信息网络服务的发展现状及思考     

孙阳  周海龙  徐爽  董莉 《测绘与空间地理信息》2020,(1):160-162

随着信息技术的发展和GIS的实际发展需求的增加,GIS逐渐转向了三维地理信息网络服务方向。在满足GIS服务发展需求的基础上,三维地理信息网络服务为空间信息的高效集成的实现作出了重要贡献。本文综述了三维地理信息网络服务的发展情况,并提出了存在的问题及相应的建议,以供参考。  相似文献   

Exploration prospects of oil and gas in the Northwestern part of the Offshore Indus Basin,Pakistan     

《China Geology》2020,3(4):633-642

Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now. In this study, the onshore-offshore stratigraphic correlation and seismic data interpretation were conducted to determine the oil and gas resource potential in the Offshore Indus Basin, Pakistan. Based on the comprehensive analysis of the results and previous data, it is considered that the Cretaceous may widely exist and three sets of source rocks may be developed in the Offshore Indus Basin. The presence of Miocene mudstones has been proven by drilling to be high-quality source rocks, while the Cretaceous and Paleocene–Eocene mudstones are potential source rocks. Tectonic-lithologic traps are developed in the northwestern part of the basin affected by the strike-slip faults along Murray Ridge. Furthermore, the Cretaceous and Paleocene–Eocene source rocks are thick and are slightly affected by volcanic activities. Therefore, it can be inferred that the northwestern part of Offshore Indus Basin enjoys good prospects of oil and gas resources.  相似文献   

山东莱芜盆地碳酸盐岩热液溶蚀特征及水文地质意义   总被引：1，自引：0，他引：1  

刘元晴  周乐  李伟  王新峰  马雪梅  吕琳  邓启军  陈晨 《现代地质》2020,34(1):199-206

鲁中山区莱芜盆地在燕山期发生大规模岩浆侵入活动,岩浆岩体外围碳酸盐岩区分布有水源地、富水块段等岩溶发育富水区,且靠近岩体含水层多发生大理岩化。富含CO₂、H₂S等酸性成分的岩浆热液流体,能对碳酸盐岩产生明显的溶蚀作用。基于岩石样品化学组分分析、水文地质调查及数据统计分析、热液溶蚀地质点详细观测,构建热液溶蚀模式,对莱芜盆地及外围热液溶蚀特征及机理进行研究。结果表明:高温高压岩浆侵入使得接触带碳酸盐岩发生热液变质大理岩化;沿渗透性断裂、裂缝以及不整合面等运移的热液流体,对碳酸盐岩地层产生酸性热液溶蚀和混合溶蚀作用,形成不同规模溶蚀孔洞,构成地下水富集空间,为寻找城镇地下水后备水源地提供新方向。  相似文献   

多层砂土地基扩底桩单桩抗压模型试验及颗粒流模拟研究     

李飞  杨俊杰  宋琦  孙涛 《中国海洋大学学报(自然科学版)》2020,(2):116-125

利用室内半模试验和颗粒流数值模拟,揭示多层砂土地基扩底桩单桩抗压承载特性及变形特征。结果表明,通过对比分析极限承载力与H_h/D(持力层厚度与扩大头直径之比)的关系可以看出,单桩的抗压极限承载力随H_h/D逐渐增加,当H_h/D超过2.0时,极限承载力基本不再增加,此时的单桩抗压极限承载力稳定在300.01~303.25 N,是H_h/D=0.5时极限承载力(183.83 N)的1.65倍。扩大头下部土体发生局部压缩-剪切破坏,破坏面从扩大头底面边缘向斜下方扩展,在水平方向影响范围达到最大后逐渐向桩内侧收缩;荷载作用越大,地基破坏区域越大,相应的极限抗压承载力也越大;持力层厚度增加,扩大头分担的荷载比例增大,分担的荷载达到稳定需要的桩顶位移也越大,H_h=0.5 D试验扩大头分担的荷载比例稳定时为60%,对应的桩顶位移约为29 mm;桩顶位移达到33 mm后,H_h=1.0~3.0 D试验稳定在63%~65%之间;通过细观颗粒流理论对砂土移动特性的研究发现,持力层厚度从0.5 D增大至2.0 D,破坏面的起始扩展角度从31°增大至42°。数值模拟研究结果与模型试验数据吻合效果良好,证明该方法分析多层砂土地基扩底桩单桩抗压荷载传递机理是可行的。  相似文献   

Provenance and tectonic settings of the Late Paleozoic sandstones in central Inner Mongolia,NE China: Constraints on the evolution of the southeastern Central Asian Orogenic Belt     

《Gondwana Research》2020

Late Paleozoic sedimentary strata outcrop extensively in central Inner Mongolia, and are a key to understanding the tectonic evolution of the southeastern Central Orogenic Belt. A combined analysis of petrography, whole-rock major and trace element, and Nd isotope is carried out on representative sandstones from the Late Paleozoic sedimentary strata (420–270 Ma). The sandstones are mainly wackes and litharenites in lithology, with low SiO₂/Al₂O₃ of 2.85–9.47 (averagely 5.22) and poor textural and compositional maturities, implying short sediment transportation between the depositional basins and provenances. The trace element compositions are generally comparable to that of the average upper continent crust (UCC), with negatively-sloping chondrite-normalized rare earth element distribution patterns ((La/Yb)_N = 3.43–11; averagely 6.94) and flat UCC-normalized trace element distribution patterns. The Nd isotopic compositions show great variation (Ԑ_Nd(t) = −5.01 to 5.35) with depositional time of the sandstones, and coincide well with the arc magmatic phases in central Inner Mongolia. The geochemical signatures of the sandstones indicate that the dominant provenances are intermediate to felsic arc magmatic rocks that have ages approximating the deposition, although old, recycled sediments may have made a minor contribution. An active continental arc setting during the Late Paleozoic in central Inner Mongolia, controlled by the northward subduction of the Paleo-Asian oceanic slab, was the most likely depositional tectonic setting of the sandstones. This active continental arc setting continued to at least 270 Ma, implying that the final closure of the Paleo-Asian Ocean along the Solonker suture zone most likely occurred sometime during the Late Permian to Early Triassic. The northward subduction of the Paleo-Asian Ocean is likely of West Pacific-style, in which the present-day Baolidao arc has a close genetic link with the South Mongolian microcontinent and, likely, the former originally formed as the arc margin of the latter.  相似文献