激光铅垂仪向上投点在地铁隧道工程中进行联系测量的实践     

高绍伟 《北京测绘》2008,(2):57-60

盾构法地铁隧道施工测量中,提高联系测量对隧道贯通起着决定的作用。本文对地铁施工测量贯通测量的误差来源进行了分配,对二井定向利用激光铅垂仪向上投点方案进行了精度分析,并和钢丝投点法的计算成果进行了比较,提出了激光铅垂仪向上投点法方案措施。  相似文献   

基于普通数码相机的近景摄影测量方法与精度的试验研究   总被引：3，自引：0，他引：3  

张慧鑫  李非栗  雷巨光 《北京测绘》2008,(4)

普通数码相机由于体积小、重量轻、价格低廉、像素几何位置精度高、影像可直接输入计算机进行处理等优点备受人们青睐。随着数字摄影测量技术的发展,数码相机分辨率的不断提高,人们开始考虑能否将普通数码相机应用于工程实践。本文以普通数码相机作为影像信息的获取手段,就控制点的数量、分布、精度、影像获取及其量测方法、数据处理解算方法、解算精度等问题进行了研究。  相似文献   

The Differentiation of Point Symbols using Selected Visual Variables in the Mobile Augmented Reality System     

Łukasz Halik  Beata Medyńska-Gulij 《The Cartographic journal》2017,54(2):147-156

On the basis of initial studies devoted to a better understanding of how the public user (a pedestrian in the city) perceives cartographic symbols in the mobile augmented reality system, we present an attempt to determine the threshold values of differentiation for three visual variables. The variables of size, transparency, and focus were implemented into image point symbols representing five types of objects. The set of symbols was designed in accordance with the rules of cartographic design taking into consideration an analysis of 19 professional tourist works. The symbols were presented on the screen of a mobile device in a system imitating the augmented reality system against four different backgrounds: white, a wall, and two typical urban landscapes. The results of an internet survey conducted using a tablet at four locations in Poznan (Poland) allowed us to determine the following: threshold differentiation values for the analysed variables, indication of the dependence on the type of background displayed on the mobile device in augmented reality, and the advantage of using a combination of visual variables.  相似文献   

BDS/GPS组合天顶对流层延迟的精度分析     

陈振国  唐龙江 《测绘工程》2017,26(9)

在现有的精密轨道和钟差条件下,选取8个MGEX跟踪站2014年6—9月的观测数据,详细分析利用BDS/GPS组合PPP法在未固定跟踪站坐标和固定跟踪站坐标情况下估计ZTD的效果,并与IGS提供的对流层产品对比分析。实验分析表明,利用PPP法估计ZTD,BDS ZTD现阶段的STD优于34mm,GPS ZTD与BDS/GPS组合现阶段的STD相当,均优于14mm。与未固定跟踪站情形下估计的BDS ZTD相比,固定跟踪站坐标的方式虽然可以提高利用BDS估计ZTD的稳定性,但不能提高精度。  相似文献   

对流层投影函数对精密单点定位精度的影响分析     

李施佳  蔡昌盛  李佳霖  易志鹏 《全球定位系统》2013,(5):22-26

对流层延迟误差是GPS定位中的一项重要的误差源,随着精密单点定位（PPP）技术的不断发展,该误差影响并制约着GPS精密单点定位精度的进一步提高。基于GPS观测值,比较分析了各种对流层投影函数模型对GPS精密单点定位精度的影响,得出了有益的结论。  相似文献   

Deconstructing Galbraith: A Geostatistical Analysis of Cartographic Intent     

《The Cartographic journal》2013,50(3):218-233

Abstract

This study uses cartometric techniques to reveal cartographic design considerations operative in Frank H. Galbraith’s 1897 railway mail service training maps. Galbraith’s maps make extensive use of humorous cartouches intended to serve as mnemonic devices for learning railway mail service routes. Poisson and quadrat point pattern analyses are performed on all eight maps in the series to determine whether the mimetic symbols are clustered along the railway mail routes or dispersed throughout the mapped spaces to achieve better graphic balance. Evidence overwhelmingly indicates that the placement of the mnemonic symbols was primarily driven by design considerations. The study therefore proves that it is possible to use cartometric techniques to deconstruct the map document to determine the cartographic design principles operative during the map's construction.  相似文献   

Mapping Everest     

none 《The Cartographic journal》2013,50(1):33-44

Abstract

From its inception in the middle of the 19th century, the Royal Geographical Society (RGS) took a keen interest in the exploration and mapping of the Everest region. This formed an integral part of the many Everest expeditions, some of which had individual surveyors or survey parties attached to them. Many mountaineers took part in this work, particularly those with a scientific background. But it was not until 1961 that a comprehensive map was produced of the Everest region.  相似文献   

市县区行政区划图的标准化研究     

周伟 《测绘与空间地理信息》2013,(12):236-237

从市县区行政区划图的编制内容、流程与地图图示方面进行了探讨,为建立市县区行政区划图的标准和制作规范提供了参考。  相似文献   

彩色扫描地图点状符号的自动识别     

骆剑承  周成虎  赵千钧  万庆 《地球信息科学学报》1999,1(2):57-62

本文初步探讨了彩色扫描地图上点状符号自动识别的方法及软件设计的模型和框架.彩色扫描地图上规则符号的主要视觉特征是颜色、形状及大小.识别符号建立在符号模式库的基础上,根据模式库中提供的颜色类型,通过颜色分层方法去寻找彩色扫描地图上的目标,然后提取其轮廓线,获取形状和大小等特征量,最后用符号特征相量与模式库中的特征相量相匹配,对符号进行判别分类,并通过坐标转换,输出符号的中心点地理坐标及符号的其他对应属性.本文最后以彩色地图上电信号强度符号的识别为实例,论述了具体应用系统的设计和开发.  相似文献   

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吴江飞  黄珹 《大地测量与地球动力学》2008,28(1):96-100

??????GPS???????λ?е?3??????????????????UofC???????????????????3???????????????GPS???????????????????У??????????????????????????????????3???????????????????????????????????????????????  相似文献