机载LiDAR点云和倾斜摄影影像数据融合处理技术流程

机载LiDAR点云和倾斜摄影影像是两种新型测绘地理信息数据,可以用来制作DEM、DOM和建筑三维模型。在分析点云数据和倾斜数据基础上,阐述点云和影像数据融合处理的关键步骤和方法。对点云配准、航带裁切、三维建模以及正射影像制作流程进行了详细阐述,开创了两种数据源融合处理的新模式。     

基于移动摄影测量的水泥混凝土路面整板换装检测

针对水泥混凝土路面整板换装技术过程中采用的传统测量方式对信息尤其是对错台量信息获取的不足,本文利用移动摄影测量方式获取摄影距离和影像重叠度相对规范化的影像信息,通过影像匹配和平差解析出所有待定点的空间信息,这些大量的三维数据的点集称为点云。并以点云数据为基础提出了一种改进的错台量批量计算方法。实验结果表明,移动摄影测量方法在满足目标精度的前提下,具有相对较高的综合效率和数据质量,且提供的点云数据结果可以批量快速计算错台量数据。     

基于综合相干系数的小数据集PS点选取算法

PS(Permanent Scatterer)点选取是PS-InSAR技术中的关键技术,SAR影像数量是影响PS点选取的重要因素。本文通过将实例数据分成不同影像数的组合,分析了影像数量对经典PS点选取算法的影响,并在此基础上提出了一种适合于小数据集PS-InSAR技术的选点算法。通过对不同数据组合的选点精度分析实验证明,相比较经典算法,本文算法充分利用了时间相干信息和空间相干信息,不仅受影像数量影响很小,而且保持了较高的选点精度和分辨率,为小数据集条件下的点目标选取提供了一种可行方法。     

基于国产高分遥感影像的城镇生活垃圾监管方法研究

就社会广泛关注的"垃圾围城"现象,本课题基于国产高分遥感影像数据参数研究城镇周边垃圾堆放点的空间、光谱等特征,建立垃圾堆放点提取模型,利用多期国产高分遥感影像数据生产相关专题产品,在太湖流域重点城市开展示范验证,建立基于国产高分遥感影像数据的城镇生活垃圾监管方法,为城镇垃圾处理管理提供新的思路和方法。     

基于AIMS航摄仪的正射影像图制作研究——以常州市为例

航空摄影测量伴随着航摄仪的快速迭代进化而不断向前发展。基于常州全市域航空摄影和正射影像图制作项目,采用AIMS航空集成多传感器航摄仪,同步获取下视影像、倾斜影像、激光点云和高光谱数据,综合运用TerraSolid和自主研发的P3C软件对点云进行分类处理,获取地表点生成DEM,对下视影像进行空三解算,利用DEM对影像进行数据微分纠正获得正射影像图。项目通过多源数据同步获取、融合处理,提高了传统3D产品的生产效率。     

数字近景摄影测量辅助三维激光影像扫描的建筑物表面数据采集系统

根据三维激光影像扫描技术和数字近景摄影测量的特点，以完整地采集复杂建筑物表面的三维坐标数据为目标，提出数字近景摄影测量与三维激光影像扫描测量相结合进行建筑物表面的三维点的采集方案，并根据设计方案和数学模型编制相关程序，初步实现相应的数据采集步骤。     

基于倾斜摄影测量点云与影像匹配的像控点坐标自动提取方法研究

近年来,激光点云与光学影像数据融合应用成为城市测绘领域一项重要的研究内容,如何利用点云数据辅助摄影测量,提高航空摄影测量的效率和精度成为研究难点。本文研究了一种基于倾斜摄影测量点云与影像匹配的像控点坐标自动提取方法,通过三维点云生成投影图,与光学影像进行匹配的方式,实现了像控点位置高精度、自动化提取,大大提升了作业效率。实验表明：利用本文方法提取像控点,并与实测像控点坐标进行较差,本文方法提取像控点坐标在X、Y、Z方向的平均误差分别为0.01 m、-0.11 m和-0.05 m。     

基于透视强度影像特征的点云配准算法

针对大规模测绘项目,靶标的布设和定位通常耗费大量人力.本文提出基于透视强度影像特征的点云配准算法,对于站-站配准,首先利用点云数据生成待配准点云的透视强度影像;其次,从强度影像中提取角点,通过特征匹配的方法确定同名点,并将同名点的像点坐标转换为物方三维坐标;最后,依据同名点的三维坐标,基于奇异值分解方法估计站-站之间的...     

无人机倾斜摄影三维城市模型研究

本研究旨在探讨无人机倾斜摄影技术在三维城市模型构建中的应用,采用无人机搭载多台相机,从不同角度获取地面影像,结合影像处理和点云生成技术,构建高精度的三维点云数据。借助多项式曲面拟合和机器学习算法,将点云数据转化为连续的三维表面模型,实现模型的精细化和真实性。研究结果表明,无人机倾斜摄影技术能够快速获取高分辨率的地面影像,并通过自动化算法实现影像匹配和点云生成,有效提高模型构建的效率和精度。通过进一步优化模型,结合虚拟现实和增强现实技术,实现对三维城市模型的沉浸式和交互式展示,为城市规划、建设和管理提供了重要的决策支持。因此,无人机倾斜摄影技术在三维城市模型研究中具有广阔的应用前景,可为城市智能化发展提供技术支持和决策参考。     

基于遥感数据与PS-InSAR的城市桥梁形变量的监测研究

本文提出一种新的监测城市桥梁形变的方法,利用遥感数据与PS-In SAR技术来监测桥梁的形变量。首先通过基于面向对象的影像提取方法,对高分2号的高分辨率遥感影像进行桥梁提取,将影像分割成由同质像元组成的影像对象,利用对象的光谱特征及空间特征进行分类提取,将影像分为陆地与河流两大类,在将陆地单独提取为一个面要素图层,同时对分类后的河流和陆地两大类别进行二值化处理,再经腐蚀膨胀开闭运算,从而得到连通的河流对象,再将河流单独提取为一个矢量图层;最后将河流与陆地两个矢量图层进行求交的空间运算获得桥梁面。其次通过合成孔径雷达干涉测量技术得到研究区大范围的地表形变矢量(shapefile)点数据。最后利用GIS空间运算将提取的桥梁面数据与形变点数据做空间叠加运算得到桥梁面内的形变点数据,然后通过反距离权重差值,获得高分辨的沉降速率图。通过对形变量的量化分析,最终得出桥梁的安全级别。     

基于倾斜影像密集匹配点云的数字高程模型更新方法研究

针对数字高程模型(DEM)更新时传统航空摄影测量方法效率低和激光雷达点云方法成本高的问题,提出了一种基于倾斜影像密集匹配点云的DEM更新方法.将倾斜影像生成密集匹配点云,然后对地形变化区域进行滤波并与未变化区域历史DEM反生成的点云合并,对合并后更新区域和接边问题进行处理后得到更新后的DEM成果.该方法更新的DEM既具...     

提取平面标靶及配准点云的自动化实现

点云配准是三维激光扫描数据处理过程中不可或缺的一个环节,利用标靶进行配准是经典的手段之一,此类方案在单独扫描标靶的基础上进行半自动化配准。本文给出一种自动配准策略,用中心投影原理将单站扫描的点云转换为深度影像,借助数字图像处理技术完成标靶的自动提取,拟合获得标靶中心点的坐标,并借用摄影测量学的知识实现点云的自动化配准。实验证明了本文方法的可靠性。     

Modeling Road Centerlines and Predicting Lengths in 3-D Using LIDAR Point Cloud and Planimetric Road Centerline Data

Abstract:   Transportation is one of a few engineering domains that work with linear objects—roads. Accurate road length information is critical to numerous transportation applications. Road lengths can be obtained via technologies such as ground surveying, global positioning systems (GPS), and Distance Measurement Instruments (DMI). But using these methods for data collection and length determination is time-consuming, labor intensive, and costly. The purpose of this study was to assess the accuracy and feasibility of an alternative. This article reports on a study that provides an alternative to obtaining road centerline lengths by measurement; instead it proposes using geographic information systems (GIS) and light detection and ranging (LIDAR) point cloud data. In this study, a three-dimensional (3-D) vector model based on linear referencing systems (LRS) concepts was developed to represent road centerlines in a 3-D space and to predict their 3-D lengths. A snapping approach and an interpolation approach to obtain 3-D points along lines when working with LIDAR point clouds were proposed and discussed. Quality control measures were initiated to validate the approach. The accuracy of the predicted 3-D distances was evaluated via a case study by comparing them to distances measured by DMI. The results were also compared to road lengths obtained by draping planimetric road centerlines on digital elevations models (DEMs) constructed from LIDAR points. The effects of the average density of 3-D points on the accuracy of the predicted distances were evaluated. This study concluded that the proposed 3-D approach using LIDAR data was efficient in obtaining 3-D road lengths with an accuracy that was satisfactory for most transportation applications.     

摄影测量与遥感学科发展现状与趋势

近年来,随着多种新型传感器和遥感平台的出现与成熟,遥感数据获取的能力得到了显著地增强,也为遥感数据的处理与应用带来了新的机遇与挑战。利用多传感器集成与各种影像、点云等数据之间的融合技术,能够有效地提高遥感数据的精度与可靠性,已成为摄影测量与遥感领域的重要发展趋势。本文分别从摄影测量和遥感两个方面对本领域的最新研究进展进行论述。其中摄影测量部分主要对各种新型传感器与平台的发展与应用进行探讨,其中包括：无人机系统、高分辨率遥感卫星、航空数码相机、机载与地面激光雷达系统以及移动测图系统,同时也对数字摄影测量处理平台、激光点云与光学影像的融合等技术进行深入分析。遥感部分则从基础物理与建模、合成孔径雷达、高光谱遥感、分类与变化检测算法等角度进行阐述。在文章的最后,对摄影测量与遥感整个学科的发展前景进行了展望。     

Using close range terrestrial digital photogrammetry for 3-D rock slope modeling and discontinuity mapping in the United States

Close range terrestrial digital photogrammetry has evolved into a useful remote characterization tool for rock slope practitioners, particularly in situations where manual discontinuity measurement may be impractical or dangerous. The primary products are high-resolution 3-D photographic surface models that have several advantages over terrestrial laser scanner point clouds, including cost, equipment portability and the ability to include discontinuities that appear as linear traces rather than flat planar surfaces. Models can be made with currently available off-the-shelf digital cameras while commercially available software provides virtual mapping capabilities that allow practitioners to identify, map, and quickly calculate the orientation of modeled discontinuities using the same experience-based logical process used by traditional fieldworkers. Comparison of manually measured and model-derived discontinuity orientations shows good agreement both between individual discontinuities and entire sets of discontinuities. Application of the technique is illustrated using five recent mining and civil engineering projects in the United States.      

A state-of-the-art review of automated extraction of rock mass discontinuity characteristics using three-dimensional surface models

In the last two decades, significant research has been conducted in the field of automated extraction of rock mass discontinuity characteristics from three-dimensional (3D) models. This provides several methodologies for acquiring discontinuity measurements from 3D models, such as point clouds generated using laser scanning or photogrammetry. However, even with numerous automated and semi-automated methods presented in the literature, there is not one single method that can automatically characterize discontinuities accurately in a minimum of time. In this paper, we critically review all the existing methods proposed in the literature for the extraction of discontinuity characteristics such as joint sets and orientations, persistence, joint spacing, roughness and block size using point clouds, digital elevation maps, or meshes. As a result of this review, we identify the strengths and drawbacks of each method used for extracting those characteristics. We found that the approaches based on voxels and region growing are superior in extracting joint planes from 3D point clouds. Normal tensor voting with trace growth algorithm is a robust method for measuring joint trace length from 3D meshes. Spacing is estimated by calculating the perpendicular distance between joint planes. Several independent roughness indices are presented to quantify roughness from 3D surface models, but there is a need to incorporate these indices into automated methodologies. There is a lack of efficient algorithms for direct computation of block size from 3D rock mass surface models.     

一种城市三维建模的新途径

本文介绍了一种新的三维建模途径,主要的数据来源是:基于“车载式近景目标三维测量系统(3D-Surs)”采集的建筑物立面点云数据和纹理图像,以及基于低空摄影测量技术获取的数据。实验表明,该建模方法具有速度快、模型的精度高、逼真度好等优点,具有较高的应用推广价值。     

基于LIDAR技术的城乡三维数据获取研究

对航空激光扫描技术进行了阐述,结合秦皇岛市测区概况,对其资料进行了分析,利用LIDAR技术对秦皇岛测区进行遥感数据采集,并产生相应的高分辨率DEM,DOM,指出LIDAR技术在基础测绘DEM,DOM生产、数字城市规划、建设、管理等领域具有广泛的应用前景。     

Accuracy of Light Detection and Ranging Derived Terrain Data for Highway Location

Abstract:   Surface terrain information is required to economically site new or relocate existing infrastructure facilities and make final design plans. Currently, ground surveying and photogrammetric mapping are the methods used by Departments of Transportation (DOTs) to acquire these data. Both the methods are time and resource intensive as they require significant data collection and reduction to provide the level of detail necessary for facility location. Additionally, conventional surveying entails data collection entirely in the field and may require personnel to be located on or near heavily traveled roadways. The research presented compares surface elevation data from Light Detection and Ranging (LIDAR) to that obtained from traditional photogrammetry and Global Positioning System (GPS) data collection for use in highway location and design. A pilot area previously mapped by the Iowa Department of Transportation was selected for evaluation. A comparison of the elevational accuracy and data quality of LIDAR with respect to two comparable collection methods is presented .     

离子液体处理油基钻屑的研究

石窟寺数字化工程中获取了大量的数据,包括：点云数据、三维模型、纹理数据以及各种图件等。针对这些数据的管理,本文提出基于文件与数据库的混合管理方法,设计并实现了具有普适性的石窟寺数字化工程数据管理系统。该系统目前已经应用在宝顶山大佛湾石刻数字化工程中。实践结果表明,采用文件与数据库混合管理方法可以有效地管理石窟寺数字化工程数据,同时,系统的应用能够提高数据的查询和使用效率。