共查询到20条相似文献，搜索用时 504 毫秒
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空间直角坐标的协因数阵转换到高斯平面上的计算公式 总被引：5，自引：0，他引：5
导出了由空间直角坐标的协因数阵向大地坐标的协因数阵；由大地坐标的协因数阵向高斯平面直角坐标的协因数阵转换的计算公式。在此基础上，导出了直接由空间角坐标的协因数阵计算高斯平面直角坐标的因数阵的简便公式。 相似文献
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论测量平差中的协因数计算 总被引：1，自引：0，他引：1
平差教材中关于协因数的计算采用逐步递推的方式,不利于教学和学生学习,而采用统一变量计算很方便直接。着重讨论协因数的统一变量简明计算及协因数矩阵的三阶求逆方法。 相似文献
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直接从GPS基线向量法方程系数阵入手,利用修正的Gram-Schmidt算法对法方程系数阵进行三角分解实现最小二乘求解,导出了基于修正的Gram-Schmidt算法求解法方程系数阵广义逆的数学公式和计算步骤,给出了通过广义逆表示的未知数解向量及其协因数阵的数学表达式.计算过程不仅避免了对矩阵的求逆,并从理论上解决了Gr... 相似文献
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阐述用方差协方差数据绘制莫尔圆，以及用莫尔圆表示点位误差椭圆各元素的方法。对用莫尔圆表征坐标中误差特性的几何意义作了探讨，取得了概念清楚、直观的效果。 相似文献
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论测量平差中的权和权阵 总被引：1，自引：0，他引：1
平差教材中关于权和权阵的论述分散在第三、四两章中,不利于教学和学生复习。先给出观测向量的方差阵,由方差阵定义协因数阵、协因数,再由协因数阵定义权阵,将更宜于教学和学习。 相似文献
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非线性观测值函数的协方差和协因数传播及其权倒数 总被引：10，自引：1，他引：10
将非线性观测值函数在其近似值处泰勒级数展开，取至二次项，得到线性－二次项形式。利用线性空间［Ｌ，Ｑ］＾Ｎ的概念和性质，将它表示成［α，β］的向量形式。定义广义协方差算子和广义协因数算子，导出了线性－二次项的非线性观测值函数的广义协方差和广义协因数传播律。在此基础上，给出了非线性平差值函数和未知数函数的权倒数公式。 相似文献
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闫伟新 《测绘与空间地理信息》2019,42(11)
针对目前隧道洞外GPS控制网横向贯通误差严密计算方法在理论上的不足,本文基于坐标转换模型和协因数传播定律推导了隧道独立坐标协因数阵的计算公式,研究了基于验后单位权中误差和隧道独立坐标协因数阵的隧道洞外GPS网引起的横向贯通误差严密计算方法。之后,以某特长铁路隧道工程洞外GPS控制网实测数据作为研究对象,阐述了横向贯通误差严密计算的技术流程。研究成果为控制隧道工程准确贯通提供了参考。 相似文献
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刘新洪 《测绘与空间地理信息》2012,35(9):167-169
最初给出的灵敏度准则是用来解决监测网中单点移动的情况,本文分析了由此产生的几种处理多点、多块移动方法的不合理性。在此基础上,提出多点、多块移动必须用相应的坐标差协因数子矩阵求最弱检测方向或某给定方向的灵敏度数值,并举例进行论证。 相似文献
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《制图学和地理信息科学》2013,40(2):184-191
The role of art in relation to maps is being reappraised on the basis of a perceived ability to depict aspects of a place that maps alone cannot. Many as opposed to one perspective on a place communicates more fully the essence of that place (with art as a valuable source of qualitative geospatial data) and so maps and art should be presented in the same visualization package. This paper outlines the development and implementation of an interface where a scanned painting forms the mode of access to an embedded sequence of maps. The interface is used to represent the history and habitat extent of the kea (alpine parrot) in New Zealand from pre human colonization times through to their present, limited range to a speculation on their future habitat. The painting and the map (in what has been termed in the literature as an anti-map / map combination) are in their own separate layers and joined by an interactive link. The interface harnesses the ability of visual art to aggregate multiple themes, locations and times into a single cohesive image, coupled with map composition and symbology that complements the painting. The ability to contain many temporal instances is close to the comic strip frame (and instances of Renaissance art) in particular, with, in this case, an implicit time frame from left to right on the painting. The use of an artistic image minimizes use of text to depict events, due to the visual and narrative power of the painting. 相似文献
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选取1996年～2004年9年间陕西省县域农民人均纯收入作为研究对象,采用GIS空间分析方法对其空间分异规律进行研究。结果表明,农民收入水平呈现明显的空间正相关,并且相关性不断提高,地域分异十分明显。 相似文献
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建立适用于多类型植被场景的热辐射方向性模型是进行地表热辐射方向性研究的一种手段。利用真实植株几何及生理参数的统计平均值来刻画理念植株,并给定其空间分布特征,进行不同生长期植被冠层的描述。基于冠层双向孔隙率思想构建了冠层热辐射方向性3维模型,模型继承了孔隙率模型在计算冠层热辐射方向性上的简洁优势同时以几何光学的思想考虑了冠层空间异质性对冠层热辐射方向性的影响。以玉米冠层为例,进行了不同生长期玉米冠层热辐射方向亮温的模拟,通过与实地测量数据的比对表明,本文发展的模型能够较准确地模拟不同生长期玉米植被场景的方向亮温变化规律,模拟误差主要来自理念株的刻画误差、玉米叶片形状的近似以及忽略了多次散射贡献等3个方面。模型的构建方法对稀疏植被场景、浓密植被场景、多类型植被的混合场景均可适用,不同观测几何下的植被场景4组份面积比计算结果有望应用于复杂地表条件下地表返照率的研究。 相似文献
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Wasim Shoman 《国际地球制图》2017,32(12):1352-1366
This paper introduces a new hierarchy for cartographic generalisation processes, applied in street networks. The aims of implementing this hierarchy are to emphasise on significant street features, and to provide more free spaces between street features. The hierarchy is obtained from the functional classes of the features and four centrality measures in a street network, i.e. betweenness, reach, straightness and closeness extracted from a primary graph. The values of centrality measures change in every zoom level by calculating a radius parameter, which depends on the users’ field of view. The coefficients for the measures are constructed using a decision-making technique called fuzzy analytical hierarchy process (FAHP). The weights for each of the centrality measures are computed and normalised to form the proposed hierarchy. The hierarchy is applied and used later in the thinning process to omit insignificant features from the street network in medium scales. 相似文献
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《The Cartographic journal》2013,50(4):300-307
Abstracttitle/>The use of soundscapes on digital maps in order to enrich our experience of the map use has been recognized as a part of other multimedia components in several previous research projects. The study described in this paper was conducted as part of ongoing research projects aiming to develop mobile and web applications for outdoor activities. The research describes the aims of finding new kinds of ways of communicating spatial information, even to those who are visually impaired, and, in general, to provide map users with a profounder use experience. The paper reviews previous studies and describes the sonic map implementations accomplished to date. The implementation examples presented cover a hiking use case in a national park. Sonic maps can help the users to plan their hike in advance and further provide those who are not able to visit the park with a multimodal experience of the atmosphere. Finally, conclusions are given and possible improvements for the future are discussed. 相似文献
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以1999-2004年间中国西部地区近650个GPS站点的观测资料为基础,采用二维“高张力样条”函数内插算法获得了连续地壳形变场。结果表明,相对于稳定欧亚参考框架,中国西部现今地壳运动西强东弱,北向运动从西向东逐渐减弱,东向运动逐渐增强,青藏高原东缘及附近地区是东向运动的消减区带;主应变从西向东由压缩应变转变为拉伸应变;最大剪应变主要位于喜马拉雅地块及其东部地区;中国西部地区地震活动在空间分布上似乎集中发生在印度板块北东向挤压欧亚板块的两条共扼带内,与地壳形变场有一定对应关系,地壳形变的高应变率区为中强地震多发地带。 相似文献
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Diwakar Paudel Jay Krishna Thakur Sudhir Kumar Singh Prashant K. Srivastava 《国际地球制图》2015,30(2):218-241
Soil is a vital part of the natural environment and is always responding to changes in environmental factors, along with the influences of anthropogenic factors and land use changes. The long-term change in soil properties will result in change in soil health and fertility, and hence the soil productivity. Hence, the main aim of this paper focuses on the analysis of land use/land cover (LULC) change pattern in spatial and temporal perspective and to present its impact on soil properties in the Merawu catchment over the period of 18?years. Post classification change detection was performed to quantify the decadal changes in historical LULC over the periods of 1991, 2001 and 2009. The pixel to pixel comparison method was used to detect the LULC of the area. The key LULC types were selected for investigation of soil properties. Soil samples were analysed in situ to measure the physicochemical soil properties. The results of this study show remarkable changes in LULC in the period of 18?years. The effect of land cover change on soil properties, soil compaction and soil strength was found to be significant at a level of <0.05. 相似文献
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The main focus of this paper is the effectiveness of dynamic point symbols in the presentation of quantitative data. Such symbols are of particular use in the design of animated maps and computer games. The authors examine three existing techniques of using dynamic point symbols to present quantitative data: blinking, pulsation, and rotation. The aim of the study is to compare their effectiveness with that of classical cartographic animation techniques. The results of the study show that in animated map design, dynamic point symbols might be used to present not only qualitative but also quantitative data with comparable effectiveness. The results may serve as the basis for designing dynamic point symbols to be as effective as the classical techniques used in animated cartography. 相似文献