基于机载LiDAR数据的海地地震震后建筑物信息提取与三维建模

机载激光雷达技术(LiDAR)可以直接获取地表高精度三维信息,载有LiDAR设备的飞机可深入到震后交通遭受严重破坏的重灾区,快速对大范围区域进行数据采集及数据分析,为灾情信息获取与评估以及震后救援提供技术支撑。本文对获得的海地雅克梅勒(Jacmel)地区震后LiDAR点云数据进行了处理和分析,通过提取建筑物矢量,生成数字地表模型(DSM),探索了震后建筑物信息提取及三维建模方法,创建了真实可量测的三维建筑物模型。结果表明,由于雅克梅勒地区距离震中较远、建筑物破坏程度较低,震后大部分建筑物完好,基于激光点云数据的震区建筑物三维重建效果较好。     

Lidar点云数据中建筑物的快速提取

Lidar技术可快速获取地表的高精度三维点云数据, 目前对此类数据的分类却是速度慢、精度低, 尤其是城市区域建筑物和树木靠得较近时更是难以准确提取建筑物.介绍了一种基于点云数据生成距离影像, 而后引入对比度纹理辅助的点云数据建筑物快速提取方法.结果证明, 该方法不需要其他辅助数据就能实现点云数据中建筑物的快速提取.      

煤矿巷道三维激光扫描关键技术及工程实践

智能化、无人化开采是煤炭行业发展的必然趋势,精准地质信息探测是当前智慧煤矿建设中的重点研发方向之一,其中巷道信息的精准探测和巷道三维模型的快速获取是地质透明化的重要数据来源。对比分析传统巷道建模方法及其优缺点,提出利用三维激光扫描重建技术构建高精度透明工作面巷道模型的技术思路。在分析煤矿井下工况环境长距离三维激光扫描面临的技术难题的基础上,研究三维激光扫描原理和空间点坐标计算方法,并提出透明工作面巷道三维激光扫描重建技术流程,其关键技术包括:三维激光扫描系统动态标定和坐标转换方法;点云预处理技术中基于统计滤波法的大尺度噪声滤波方法和基于移动最小二乘的小尺度噪声滤波算法;点云关键点提取与特征描述技术中SIFT特征检测算法和FPFH特征描述算法;点云配准技术中基于FPFH特征描述算法的粗配准技术和基于迭代最近点算法的精配准技术。以准格尔煤田唐家会煤矿某工作面为研究对象,利用自主研发的移动式三维激光扫描系统从三维激光扫描施工流程、巷道点云数据采集、边界轮廓线提取、巷道与工作面联合建模等方面进行实践应用。结果表明,提出的基于三维激光扫描技术的工作面巷道三维重建思路在技术上是可行的,能为复杂巷道的快速三维扫描、重建提供一条可行的技术路径。      

三维激光扫描技术在滑坡物理模型试验中的应用

大型滑坡物理模型试验中常采用高精度的特征点监测,缺少整体变形资料;而三维激光扫描技术可以高精度、快速、完整地扫描实物,获得海量的点云数据,构建实物的数字化模型,从而详细描述表面细部状况。将三维激光扫描技术引入到滑坡物理模型试验坡体表面整体变形监测中,通过数字仿真试验对点云数据4种变形测量方式进行了对比和评价,推导了点云数据单个扫描点的空间位置精度的评价模型,对点云密度进行了理论分析。通过滑坡物理模型试验实例,采用点云比较、重心法、点云叠加方法测量模型的整体变形和单个监测点的位移,对滑坡不同演化阶段变形特征进行了综合分析。研究表明:空间位置精度的评价模型、点云密度模型为三维激光扫描变形监测的测量成果评定,测量方案的优化设计提供了必要的理论基础。点云叠加、点云比较为面测量,可以获得整个模型坡面的变形和位移情况,测量模型的变形趋势和变形量级,重心法、拟合法则属于点测量,可以获得单个监测点准确的位移量。基于三维激光扫描技术坡面监测是结合点测量和面测量的优势,在保证高精度特征点监测同时,获得模型坡面的整体变形和位移。     

基于多源数据融合技术的古墓室内外三维建模方法研究

为解决单一数据源建模中存在的信息不完整、粘连等问题,本文研究提出了一种基于多源数据融合技术的建模方法。其基本原理在于将地面激光点云与空地影像进行坐标融合,通过坐标转换,实现航摄影像坐标向激光点云所在的局部坐标系中的转换,确保点云与影像特征点成功匹配,进而完成三维模型重建工作。文章结合洞耳村蒙元墓的三维重建工作,深入分析了融合多源数据建模方法的数据采集、三维建模等关键问题。同时,本文采取可靠的成果评价体系,对最终成果进行精度评定,数据结果表明:基于地面激光点云与空地影像融合技术构建的三维模型具备更高的精度、完整性及真实性。     

三维激光扫描装置设计与数据处理

三维激光扫描仪克服了传统的单点测量方式,可以方便地对实物进行复制建立立体模型。笔者简单介绍了三维激光扫描仪构造及其实现的原理,利用自行购买的激光雷达、相机和电控平台等部件搭建三维激光扫描平台,利用串口通讯实现对激光雷达、相机和电控平台等硬件控制,进一步完成三维激光扫描点云生成及图像获取,并对生成的点云进行了精度校正,最后基于特征点拼接多幅扫描图像并成功地实现了扫描点云和图像的匹配融合,其中点云精度和图像融合效果较好。     

三维激光扫描技术获取高精度DTM的应用研究

三维激光扫描技术又被称为实景复制技术,是测绘领域继GPS技术之后的又一次技术革命,它突破了传统的单点测量方法,具有高效率、高精度的独特优势。三维激光扫描技术能够提供扫描物体表面的三维点云数据,因此可以用于获取高精度高分辨率的数字地形模型。本文将以一工程边坡为例讨论利用三维激光扫描技术快速获取数字地形模型的方法,着重论述三维点云数据的获取、拼接、坐标校正、去噪及数字高程模型的生成方法,由此得出在一定空间范围内利用三维激光扫描技术快速获取高精度高分辨率的数字地形模型具有可行性。     

基于点云数据的黄土公路边坡病害识别

公路边坡病害巡查是高速公路安全运维的重要工作之一。鉴于当前人工巡查的局限性,提出了一种基于无人机倾斜摄影技术实现三维重建和点云数据分析的公路边坡坡面病害巡查方法。研究结果表明:无人机倾斜摄影可以快速获得研究区的实景影像和点云数据,通过三维模型重建和点云数据分析,能够高效定量地识别出坡面变形、冲沟以及排水沟淤堵等边坡病害;点云数据对比算法对边坡病害识别结果有较大影响,相比最邻近点云比较方法和基于法向量的点云比较方法,点云网格比较方法更适用于公路边坡坡面病害识别。该方法提高了边坡巡查的效率,弥补了人工巡查的不足。     

基于综合改进ICP算法的三维激光扫描技术在露天矿边坡测绘中的应用

以先后发生过两次大规模滑坡的中煤平朔公司东露天矿边坡为研究背景,利用三维激光扫描技术测绘速度快、测量精度高、数据量大的特点,对该露天矿边坡进行三维激光扫描,尤其是对发生过滑坡的两个重点区域进行精细扫描。基于综合改进ICP算法,将扫描得到的多站点云数据进行拼接处理,完成了长约2 km的露天矿边坡三维模型重建。研究结果表明,三维激光扫描结果符合工程实际特征,是一种快速建立矿山边坡数字模型的有效手段。      

基于激光测量和FKM聚类算法的隧洞岩体结构面的模糊群聚分析

岩体隧洞结构面的数量、产状和发育情况是评价隧洞透水性和稳定性的重要指标。采用三维激光测量技术可以快速获取隧洞周围岩体激光点云数据和结构面的几何信息。提出了基于柱面投影和Delaunay生长算法的激光点云的三角网重构技术,利用构建的三角网平面方程的法向向量计算出单个三角网平面的产状,并应用FKM聚类算法进行隧洞岩体结构面产状的模糊群聚分类。该方法可以快速得到不同组的优势产状,且分类结果可用不同颜色进行空间显示。最后运用自主研发的FSS软件对某隧洞的岩体结构面优势产状进行了研究,研究结果表明：1）基于柱面投影和Delaunay生长法的点云构网方法特别适合于隧洞工程,构网速度快、效率高,重构得到的三角网表面与被采样的岩体表面拓扑差别最小;2）FKM模糊群聚方法对隧洞岩体结构面的群聚分类结果可靠、合理,具有较强的通用性和推广性。     

一种基于面向对象辅以DSM的建筑物提取方法

基于面向对象技术并辅以DSN的方法来快速提取建筑物信息,从LiDAR点云数据生成的DSM中提取到坡度信息,并根据对象的高度信息来提取到建筑物的大致轮廓,然后分割建筑物轮廓外的对象,依据已分建筑物对象的空间信息、形状信息及光谱信息来优化建筑物轮廓。实验结果表明,提取到的对象的正确率为97. 9%,完整率为96. 4%。     

A catalog of star-forming regions in the galaxy

This Catalog of Star-Forming Regions in the Galaxy contains coordinates and fluxes of young objects in the radio and infrared, as well as data on the radial velocities of recombination and molecular lines, for more than three thousand star-forming regions. In addition to photometric and kinematic data, we present information on diffuse and reflecting nebulae, dark and molecular clouds, and other objects related to young stars. The catalog consists of two parts. The main catalog lists star-forming regions in order of Galactic longitude and is supplemented by analogous information for star-forming regions in complexes of dark clouds with large angular sizes that are closest to the Sun. The main catalog is located at http://www.strasbg.-u.fr/pub/cats. In our preliminary study of the catalog data using a formal classification of the star-forming regions, we subdivided these objects into several classes and characterized them as being populated primarily by massive or low-mass stars at early or late stages of the star-formation process. We also distinguish between relatively nearby and distant complexes.     

利用GEOSIS软件平台建立三维地质可视模型——以典型岩溶流域湖南洛塔为例

探讨了洛塔典型岩溶流域在缺乏钻孔资料的情况下,利用系列地质剖面、地质图、DEM等现有资料建立三维地质模型的建模方法及模型的应用。其中地质剖面数据的获取采用了计算机自动提取地形高程、地层界线、地下河位置等信息制图,精确快速。三维建模过程使用Geo SIS三维地质建模软件平台,以超体元实体模型、断层数学模型、褶皱几何模型等进行建模,模型形象逼真。建好的三维模型可以进行任意方向、角度的切割;进行地下漫游、放大、三维观察地层与断层之间的关系;进行揭层三维显示及单层三维显示; 进行任意形状的开挖显示。从建模的角度考虑,该方法对仅有地形图、水文地质图和极少量钻孔资料的情况下建立三维地质模型,具有普遍推广的意义。      

城镇地籍基础地理数据建库方法探讨

通过对第二次全国土地调查城镇地籍调查数据建库标准的分析,提出一套基于大比例尺城镇地形图开展基础地理数据建库的方法,探讨利用数据建库成果地形图图式的符号化回放,既满足城镇地形图的出图效果又满足基础地理数据GIS方法管理的需求.     

The potential of point clouds for the analysis of rock kinematics in large slope instabilities: examples from the Swiss Alps: Brinzauls,Pizzo Cengalo and Spitze Stei

Landslides - Lidar measurements and UAV photogrammetry provide high-resolution point clouds well suited for the investigation of slope deformations. Today, however, the information contained in...     

3D modelling strategy for weather radar data analysis

Weather radar data, which have obvious spatial characteristics, represent an important and essential data source for weather identification and prediction, and the multi-dimensional visualization and analysis of such data in a three-dimensional (3D) environment are important strategies for meteorological assessments of potentially disastrous weather. The previous studies have generally used regular 3D raster grids as a basic structure to represent radar data and reconstruct convective clouds. However, conducting weather radar data analyses based on regular 3D raster grids is time-consuming and inefficient, because such analyses involve considerable amounts of tedious data interpolation, and they cannot be used to address real-time situations or provide rapid-response solutions. Therefore, a new 3D modelling strategy that can be used to efficiently represent and analyse radar data is proposed in this article. According to the mode by which the radar data are obtained, the proposed 3D modelling strategy organizes the radar data using logical objects entitled radar-point, radar-line, radar-sector, and radar-cluster objects. In these logical objects, the radar point is the basic object that carries the real radar data unit detected from the radar scan, and the radar-line, radar-sector, and radar-cluster objects organize the radar-point collection in different spatial levels that are consistent with the intrinsic spatial structure of the radar scan. Radar points can be regarded as spatial points, and their spatial structure can support logical objects; thus, the radar points can be flexibly connected to construct continuous surface data with quads and volume data with hexahedron cells without additional tedious data interpolation. This model can be used to conduct corresponding operations, such as extracting an isosurface with the marching cube method and a radar profile with a designed sectioning algorithm to represent the outer and inner structure of a convective cloud. Finally, a case study is provided to verify that the proposed 3D modelling strategy has a better performance in radar data analysis and can intuitively and effectively represent the 3D structure of convective clouds.     

Extracting the damaging effects of the 2010 eruption of Merapi volcano in Central Java, Indonesia

This research focuses on providing information related to the damaging effects of the 2010 eruption of Merapi volcano in Central Java, Indonesia. This information will be used to help emergency responders to assess losses more timely and efficiently, and to monitor the progress in emergency response and recovery. The objectives of this research are: (a) to generate a map of pyroclastic deposits based on activities pre- and post-volcano eruption of 2010 in the research area, (b) to investigate the impact of volcano eruption on the environment, and (c) to assess the impact of volcano eruption on landuse. ALOS PALSAR remote sensing data pre- and post-disaster were used in this research for mapping the volcano eruption. Topographic and geomorphological maps were analyzed for profiling and field orientation, which were used to investigate the impact of volcano eruption on the environment. SPOT 4 satellite images were used in this research for updating landuse information from the topographic map. The result of the landuse updated data was used for assessment of the volcano eruption’s impact on landuse with the GIS raster environment. The volcanic eruption that occurred in 2010 is estimated to have an impact of 133.31 ha for settlements, 92.32 ha for paddy fields, 235.60 ha for dry farming, 570.98 ha for plantations, 380.86 ha for bare land, and 0.12 ha for forest areas. An estimate of the number of buildings damaged due to the volcano eruption in 2010 was carried out by overlaying a map of pyroclastic deposits and the information point of the building sites from the topographic map. The total number of buildings damaged is estimated to be around 12,276 units.     

浅海海底表层速度建模技术及其应用研究

浅海海底起伏和速度变化对OBC资料成像质量产生较大影响。建立浅海海底表层速度模型不仅能够解决OBC资料的静校正问题,也可用于海底反射系数计算、双检资料合并、多次波压制等,但是,目前针对浅海海底表层速度建模的研究还不多。文中提出了针对浅海地区OBC资料的海底表层速度建模的三维初至走时反演技术,主要包括:(1)震源位置校正技术。根据地震波在海水中传播特征,把在海水中激发的震源位置校正至海底,使震源和接收点都位于海底,利于初至走时反演计算;(2)快速三维初至走时反演方法。利用回折波走时和射线方程,形成了高效率初至走时反演方法。将该技术应用于胜利油田莱州湾浅海区海底OBC资料的处理中,建立了三维海底表层速度模型,用此速度模型进行静校正,取得了良好的应用效果。     

Automatic identification of continuous or non-continuous evolution of landslides and quantification of deformations

Landslides - Nowadays, the 3D modelling of surfaces is widely used to provide point clouds in geosciences. To study the evolution of landslides, many point clouds are available but post-processing...     

Corner points localization in electronic topographic maps with deep neural networks

Digitized topographic maps normally have to go through the geometric calibration before practical utilization. Nowadays, the reference points for the calibration are still manually assigned. Corner points (graticule intersections) in a map are usually good candidates in favor of the reference points. This paper proposes an algorithm for automatically locating the corner points in the electronic topographic maps by detecting the specific rectangle objects in the map corners. It assigns the probabilities to each row and column in the region of interests (RoIs) to provide information regarding the location of the objects. In order to facilitate the object detection with high level visual features, the deep neural networks (DNNs) are employed in the proposed algorithm. For the object proposal, the sliding window scheme is adopted. The experimental results indicate that the proposed approach outperforms the conventional bounding-box regression method in both detection and localization accuracy. For the proposed algorithm, the average F1 score in the object detection is 0.91, which is 12% higher than the conventional model. The mean Euclidean distance between the predicted corner points and the ground-truth by the proposed algorithm is 2.22 pixels, 35.8% lower compared with the regression based model.