地面三维激光扫描仪测量精度的评价分析

针对地面三维激光扫描仪用于城市轨道交通变形监测的精度评价,本文研究了三维激光扫描仪本身、外界环境和被扫描目标3个误差源,对三维激光扫描仪的测距和测角精度进行了评定,并通过试验分析了三维激光扫描技术用于轨道交通变形监测可行性。     

自定位手持式三维激光扫描仪精度测试与分析

三维激光扫描技术是一种高精度高效率的测绘新技术,在逆向工程、三维可视化、虚拟现实等领域被广泛使用。手持式三维激光扫描仪是三维激光扫描仪的一种,其便携性和高精度的特点使其在文物考古、医学等领域具有独特的优势。但在应用过程中,实际获取的扫描数据精度往往会受到仪器自身、扫描目标及外界环境的影响。本文对手持式三维激光扫描仪的误差来源进行了分类,并针对各个误差来源进行分析,然后以EXAscan手持式三维激光扫描仪为例,设计了相应的试验方案并对其精度进行了测试与分析。     

地面三维激光扫描仪的检校与测量精度评定

针对地面三维激光扫描仪的测量精度评定问题,提出了利用比长基线检定场进行测距精度评定,利用多齿分度台进行水平角精度评定,利用室内检校场进行垂直角和点位精度评定。采用比长基线检定场方法,每个观测点布设稳固,且有强制对中装置,能够较好地减少其他误差的影响。采用多齿分度台利用全圆组合比较法进行水平角精度评定,该方法所用的角度标准器精度高,可溯源。基于Riegl VZ-1000的试验结果表明,本文所提出的方法对地面三维激光扫描仪进行性能评定可靠性好、稳定性强,对地面三维激光扫描仪的检校研究具有一定的参考和应用价值。     

三维激光扫描仪在建筑立面测绘中的应用

三维激光扫描技术以其高效、高精度的特点,成为建筑立面测绘的新方式.本文介绍了基于徕卡RTC360三维激光扫描仪的建筑物立面测绘技术流程,结合工程实例,对建筑立面测绘成果进行了精度评定,验证了将三维激光扫描仪应用于建筑立面测绘的可行性.     

地面三维激光扫描点位精度评定

通过建立高精度控制网作为室外检校场,借助标靶对Leica ScanStation2型三维激光扫描仪进行实地测试,并对达到的点位精度进行分析与评定,得出该仪器扫描距离为40 m、80 m时,点位精度分别为±4.7 mm和±6.3 mm.研究结果可为三维激光扫描技术的进一步应用提供经验和借鉴.     

地面三维激光扫描仪测距检校与精度评定

作为一项新的数据获取技术,地面三维激光扫描技术正被越来越多地应用于多个领域,同时也对该技术测量精度提出了更高的要求。本文根据六段解析模型设计合理有效的试验过程,拟对徕卡C10三维激光扫描仪的测距检校与精度进行评定,为提高今后地面三维激光扫描仪测量精度提供参考。     

重载铁路检测装备中三维与二维激光扫描仪检校方法

重载铁路的线路运输量大、承受载荷大、线路磨损劣化快,为保障运输安全,需要高频次、常态化地对线路进行静态检查和测量。基于轨道的移动三维激光系统可快速扫描、高效获取铁路通道三维实况,是一种新型的重载铁路基础设施测量检测的手段,但受限于三维激光数据精度低、无法满足对轨道轮廓进行精准测量,本文设计了一种集成三维相位式激光扫描仪和二维线激光扫描仪的重载铁路检测装备,提出了三维与二维激光扫描仪的检校方法。试验结果表明,该方法可实现三维激光数据与二维线激光数据优于2 mm的精准融合,为后续基于毫米高精度三维激光的铁路基础设施一体化综合测量与分析奠定了良好的数据基础。     

天宝三维激光扫描仪在防空洞测量中的应用

采用三维激光扫描仪对防空洞进行测量的目的是实现防空洞的3D立体化表达,把防空洞的空间位置、四至、走向等直观精确地表现出来,从而提高防空洞空间体积计算的精度,并在很大程度上提高非专业管理人员对防空洞的管理能力.采用天宝SX10三维激光扫描仪对现场进行导线布设、三维扫描等,获得了高精度防空洞点云数据,并对点云数据进行精度验...     

手持式三维激光扫描仪在文物保护中的应用

手持式三维激光扫描仪适合建立高精度的模型,建立的模型常常被作为文物复制和修复的基准,被广泛应用于文物保护中。以VIUSCAN为例介绍了手持式三维激光扫描仪的特点和测量原理,对手持式激光扫描仪在文物逆向重建中的应用进行详细的阐述,通过与传统激光扫描仪对比分析,验证手持式三维激光扫描仪在文物保护中的优势。并提出了解决手持式三维激光扫描仪在文物三维重建中问题的有效措施。     

利用移动最小二乘法进行点云变形分析的研究

三维激光扫描仪能够高精度快速翔实地获得变形体的空间信息,同时诸多变形体的变形情况也需要完整的描述和分析。为此,本文通过三维激光扫描仪获取变形体变形前后的点云数据,并利用移动最小二乘法进行均匀格网拟合内插来提取变形信息。通过模拟简支梁加载试验和上述方法进行变形分析,并与TS30高精度测量机器人的测量结果进行对比,结果表明两者精度相当,能够探测到毫米级变形。     

阿克苏河-塔里木河水系水质污染遥感监测与评价

 采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的 污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体 污染变化曲线,得出污染物浓度随着远离上游而增加。     

Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data

The hard-rock hilly Aravalli terrain of Rajasthan province of India suffers with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. In the present study, detailed analysis of meteorological and hydrological data of the Aravalli region has been carried out for the years 1984–2003. Standardised Precipitation Index (SPI) has been used to quantify the precipitation deficit. Standardised Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) and Vegetation Health Index (VHI) have been computed using NDVI values obtained from Global Vegetation Index (GVI) and thermal channel data of NOAA AVHRR satellite. Detailed analyses of spatial and temporal drought dynamics during monsoon and non-monsoon seasons have been carried out through drought index maps generated in Geographic Information Systems (GIS) environment. Analysis and interpretation of these maps reveal that negative SPI anomalies not always correspond to drought. In the Aravalli region, aquifer-stress shifts its position time to time, and in certain pockets it is more frequent. In comparison to hydrological stress, vegetative stress in the Aravalli region is found to be slower to begin but quicker to withdraw.     

Landslide risk analysis between Giri and Tons Rivers in Himachal Himalaya (India)

The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies.     

Gravity Changes Before Large Earthquakes in China: 1998-2005

Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200...     

GNSS系统及其技术的发展研究

阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议.     

“4D”技术及其应用

介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。     

Virtual Australia: its key elements – know,think, communicate

Abstract

Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised.     

地理数据库的关系模型及其实现

本文从以图论观点分析地理实体入手,系统阐述了地理数据库关系模型的设计法和过程。作者于1984年4～9月间在微型机上设计建立了关系型地理数据库的实方验系统(RGDB)。该系统采用了本文提出的关系模型,采用了可动态扩库的子库组合结构,这种结构具有灵活性和提高空间利用率的优点。RGDB含有多种功能的数据操作命令,除了具有一般检索功能外,还能进行“开窗”选取和十分“自由”的映象选取。本文对RGDB系统的主要性能和实现途径作了扼要介绍。     

Toward seamless indoor-outdoor applications: Developing stakeholder-oriented location-based services

Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders.     

基于WebGL的三维智慧管网系统的设计与实现

随着城市面貌日新月异,地下管网的建设也在持续推进,作为城市的地下“神经网络”,全天24 h保障城市的正常运转和发展。本文以实现城市管网管理系统的高可用、无插件、智能化为目标,采用“地上地下一体”“二三维一体”的设计理念,研究基于WebGL的三维智慧管网系统的关键技术,实现了管线设施管理的信息数字化、空间化与图形化。