安(阳)林(州)铁矿整装勘查区控制测量中RTK高程精度的探讨

随着GPS-RTK在矿区测量中大范围的普及应用,鉴于RTK高程测量精度的不确定性,结合实际工程中测量数据的统计、分析结果,针对影响RTK高程测量精度的各种因素,提出了提高RTK高程精度的具体措施,得出了在一定测区范围内RTK高程测量的精度能满足图根高程的结论。     

静态GPS测量与RTK测量实例分析

结合嘉兴市一个四等GPS测量控制网、RTK动态测量的实例,分析实际应用中的若干问题。数据分析表明:在平面、高程检核标准分离的原则下,严格控制GPS基线网中高程闭合差,合理选择分布较好、精度较高的高程拟合点,可使GPS静态网的高程拟合接近或达到四等水准精度;动态RTK测量中,采用双基准站双采样(或多采样)的方法,可有效消除基准站坐标误差对RTK采样点平面坐标的系统影响,削弱对流层随机变化对RTK高程测量的影响,从而使RTK平面坐标测量满足城市一级导线测量的需要,使RTK高程测量接近或达到四等水准测量的精度。     

GPS网络RTK流动站的对流层内插改正分析

介绍网络RTK常规内插模型,分析内插法的精度,从单站上分析高程对天顶距延迟的影响,分析高程差异对双差对流层延迟的影响,利用网络RTK内插法只可消除其中大部分的误差.这对利用网络RTK算法生成流动站的误差改正数具有重要的参考价值.     

基于SDCORS的网络RTK在工程测量中的精度分析

针对基于SDCORS网络RTK测量精度进行研究,通过实验分别对两种GPS接收机安置方式的测量精度进行对比,并对网络RTK测量精度的时间变化进行分析,结果表明:1)网络RTK平面控制测量时应该使用三脚架安置GPS接收机。对于高程测量,利用三脚架与对中杆安置GPS接收机对大地高程测量精度影响较小;2)网络RTK测量偶有大误差测量结果出现,应取多次观测结果进行成果检核;3)网络RTK测量相近历元的观测误差具有相关性,如果有条件,最好在不同时间段多次测量取平均值。     

基于RTK的水文地质勘察测量研究

在水文地质勘察中需要测量水文地质观测点的平面坐标与高程,RTK测量可以满足其平面坐标精度,而能否满足、怎样满足其高程精度值得探讨。将RTK测高技术应用于水文地质勘察测量中,通过对测量成果统计与检核,发现只要采取一定的质量控制措施,满足RTK测量条件,在测量过程中注意检核,RTK高程就可满足水文地质勘察测量的精度要求,并明显提高了工作效率。     

新疆基础测绘工作中GPS RTK技术高程精度的分析研究

通过对生产中得到的原始数据进行归纳统计,对GPS RTK技术施测像片控制点的高程精度进行分析研究,对GPS RTK技术施测像片控制点高程的精度保障措施进行归纳总     

复杂条件下提高RTK观测高程精度的研究与分析

贵阳二戈寨测区1:2 000像控点联测,在不增加其他设备的情况下,从影响RTK高程精度的因素分析入手,通过对该地区部分像控点的观测数据的试验,按1:500像控点联测高程的精度要求,在山地和林区等复杂观测条件下,提出提高RTK观测高程精度的措施,得出有益的结论.     

长距离网络RTK区域电离层延迟实时改正

针对网络RTK基线过长时电离层延迟的相关性就会减弱的问题,本文提出了一种长距离网络RTK区域电离延迟改正模型。首先利用已知载波值和确定的非差参考模糊度计算基准站的电离层延迟,进而传播至流动站,最后内插计算流动站电离层延迟,得到电离层延迟改正。通过实测CORS数据进行验证,结果表明,该算法可使长距离网络RTK达到厘米级精度的定位结果。     

网络RTK在平原微丘区线路测量中的应用

与传统的单基站RTK相比,网络RTK具有覆盖面广、定位精度高、可靠性高、响应快速、成本低廉、推广容易的优势,可有效提高线路工程测量的效率。阐述网络RTK在平原微丘区线路测量中的应用方法,通过应用实例分析验证网络RTK的测量精度。结果表明,为确保线路测量的高程精度,应满足测量点距最近控制点的距离不大于2 km的要求,并加强外部检核;对可能存在高程检核不符情况,可根据检核结果进行高程改正,能有效消除系统误差的影响。     

北京城镇航测1∶500成图若干问题探讨

北京东部地区地面沉降每年约5,在观测条件不良时网络RTK高程测量数据会出现粗差。地面沉降降低了高程起算点的精度,网络RTK高程粗差影响地形图高程注记点的高程精度。空域控制限制了1∶500地形图摄影的飞行高度,影响摄影比例尺的选择。城镇现代建筑的三维趋势,引起航测内业采集的线不是建筑物与地面的交线,造成地形图平面精度的降低。结合实例,叙述了应用数字航空摄影测量测绘1∶500地形图的作业流程。探讨了减少地面沉降对高程起算点和地形图的影响的方法,以及加大野外精确测量保证成图质量的措施。     

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。     

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...     

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.     

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.     

使用FME与VBA提取机场方格网高程数据

因受机场工程设计软件的测量数据容量限制,基于LiDAR采集、点云分类后得到的地面点云数据LAS不能完整应用于目前设计软件进行设计计算。本文通过对拟选技术方案的筛选,提出了利用FME Workbench数据处理功能,结合VBA编程获取外部方格网平面数据的方法。该方法在FME Workbench中实现了地面点云数据构建TIN、采用逐点内插方法从TIN中提取方格网高程数据、等高线生成及相应图形处理与成果输出。最终通过实际算例证明了该方法的有效性。     

“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。