三维激光扫描的龙柱倾斜观测方法

针对城市高耸建筑物倾斜观测作业时间长、信息量少的问题,将三维激光扫描技术应用到城市高耸建筑物变形监测领域,探讨对无观测标志、不可或不便攀登的城市高耸建筑物进行倾斜观测的施测方法。以龙柱为例,制定了可行的测量方案,并采用高斯曲面拟合算法对其表面进行拟合,精确计算出龙柱的倾斜量,且与全站仪倾斜观测结果进行对比。结果表明,该方法可以快速、全面的获取观测对象的整体信息,且能够满足高耸建筑物倾斜观测的精度要求。     

逆向工程技术在建筑物倾斜测量中的应用

针对目前传统倾斜测量方法不能够全面反映建筑物倾斜变形的问题,提出一种新的基于逆向工程技术的倾斜观测方法,该方法能够较全面地反映建筑物各个部位的倾斜变形情况。基于烟囱倾斜测量的实验结果表明,所提方法不仅可以快速获取监测物体的三维点云数据,还能够准确计算出建筑物的重点监测部位。研究结果可应用于一般建筑物和塔形建筑物的倾斜观测。论文将逆向工程技术引入到倾斜测量领域中,可以更加全面、直观、形象地反映建筑物的倾斜情况。     

倾斜摄影技术在城市“三旧”改造中的应用

为验证倾斜摄影测量技术在城市“三旧”改造中的可行性,本文通过无人机倾斜摄影测量技术在东莞市石碣镇“三旧”改造中的应用实例,从影像获取、像片控制测量、空中三角测量和成果应用等环节,提出了一套利用倾斜摄影技术服务于城市“三旧”改造中的具体技术流程和方法,测试结果表明：基于无人机倾斜摄影成果,完全可以满足“三旧”城市改造中1∶500数字化地形图数据采集、土地利用现状和宗地权属调、“三旧”区域城市风貌及古建筑三维模型构建、房产面积测算及建筑密度、容积率计算等业务需求,为倾斜摄影测量技术在城市“三旧”改造中的应用提供了完整的解决方案和思路。     

无人机倾斜摄影测量技术在古建筑保护中的应用

随着社会经济的不断发展,全国各地的古建筑在不同程度上受到破坏,历史悠久的建筑文化遗址正在面临着严峻的考验,古建筑的保护工作成为当下关注的焦点。基于对古建筑预防性保护的目的,本文采用无人机倾斜摄影测量技术,以西藏某区域藏传佛教寺庙为例,阐述了无人机倾斜摄影测量的基本原理及其在古建筑保护中的应用流程,并通过实测古建筑特征点和特征边长,对构建的古建筑三维模型进行了精度分析。结果表明：通过无人机倾斜摄影测量技术生成的古建筑三维模型具有高精度的空间信息和丰富的纹理信息,模型精度达到了厘米级,对于古建筑保护工作具有较高的参考价值。     

应用湖泊中心点作为控制点实现大区域遥感影像的配准

在进行北美阿拉斯加地区多期影像湖泊变化分析过程中,由于该区域长期被冰雪及湖泊覆盖,几乎没有较明显的地面标志点可作为影像配准控制点,给影像的配准工作带来困难。在分析长时相区域湖泊形状变化的基础上,认为湖泊中最稳定的点为湖泊的中心点,该点位置随湖泊面积的变化不大,可以作为影像配准的控制点。与多边形质心相比,多边形的最大内圆圆心始终位于多边形的内部,且以该点为圆心的内圆半径最大(对应的内圆即为最大内圆),其计算方法可以应用矢量多边形的Voronoi图来求得。本文在分析简单多边形Voronoi图性质及其计算方法的基础上,提出了一种面向复杂多边形的最大内圆圆心点查找方法,给出了其算法实现流程与算法的复杂度分析。通过北美阿拉斯加地区湖泊最大内圆圆心查找的测试实例,表明本文提出的方法能够较好地计算出各种复杂矢量多边形的最大内圆圆心点,并达到较高的计算效率,且以多边形最大内圆圆心点作为配准点实现的影像间配准效果也较好。     

地基GPS倾斜路径水汽计算方法研究

介绍了倾斜路径水汽的计算原理及微波辐射计探测水汽的方法,利用GPS与微波辐射计WVR的并址观测站2002年5月26日的观测数据进行实验,证明利用地基GPS可以实现倾斜路径上可降水汽量(SWV)的计算,其与WVR观测值的偏差平均值为1.83 mm,均方根误差为4.23 mm.实验同时证明:倾斜路径水汽含量与卫星高度角有很强的关系,高度角较低时,误差较大,高度角较低时,误差较小.     

复杂多边形快速融合算法与实现

空间矢量数据结构复杂且信息丰富,复杂多边形作为矢量数据的重要组成部分,可由多个外环链和内环链组合而成,复杂的拓扑关系给相应算法的实现带来了极大困难。多边形快速融合作为GIS的基本功能,需要快速实现对任意、多个、复杂多边形的融合处理。根据多边形重心进行行列划分,利用排斥实验和多线程技术,实现了对任意多个复杂多边形的快速合并。算法已在生产实践中得到应用。     

高层建筑物倾斜观测的一种新方法

结合具体的高层建筑物倾斜观测项目的特点,提出了一种新的建筑物倾斜观测的方法—自由双视线法,阐述了该方法的观测和计算方法、精度分析以及归算方法。自由双视线法相对于传统建筑物倾斜观测方法具有很明显的优越性,对类似的项目具有一定的借鉴意义。     

顾及几何形状相似性的简单多边形最近距离计算方法

提出简单多边形距离计算方法,在计算简单多边形最近距离的同时,可以求得多边形之间彼此面对的线段链.针对多边形之间不同位置关系,给出不同的最近距离和多边形之间彼此面对线段链的计算算法.     

交错导线闭合环中观测角度总和理论值的计算和公式的推证

笔者在矿山井下做过多年矿山测量工作 ,多次碰到交错导线闭合网的测量情况。在计算交错导线闭合网角度总和的理论值时 ,发现交错导线闭合网角度总和理论值 ,用多边形外角和 180°(n+2 )及多边形内角和 180°(n- 2 )分别计算 ,虽可计算出来 ,但分辨内角多边形和外角多边形时 ,角度易混淆出错 ,可能造成整个交错导线闭合网角度理论总和不符 ,且分别计算次数多。后来经过图形研究和参阅资料 ,找到了正确的一次计算方法 ,并对计算公式作了推证。现将它介绍给同行们 ,供参考。先分别计算具有内角和外角图形角度理论总和。如图 1所示 ,角度观测值…     

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.     

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.     

GIS空间数据的采集误差及其分析

本文详细阐述了GIS数据采集过程中的误差来源，重点分析了通过地图、遥感和摄影测量等方式采集数据所产生的误差及其特性，分析了其对GIS数据的影响与消减方法。     

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。