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1.
移动地图的自适应模型研究   总被引:6,自引:0,他引:6  
作为一种新的电子地图应用模式,移动地图的制图模型和应用模式都不同于其他类型的地图。在分析移动地图特点的基础上给出移动地图自适应要素的数据模型与组件结构,将自适应要素划分为时空要素、操作要素、技术要素、信息要素、用户要素以及使用环境要素等。移动地图自适应模型的研究可以指导移动地图的设计,实现其服务的个性化和智能化。  相似文献   

2.
基于数据库存储方案的高性能瓦片地图服务研究   总被引:1,自引:0,他引:1  
实时渲染与网络传输是影响WebGIS性能的两大因素,瓦片技术是改进系统性能的最佳选择,它通过对地图数据预先渲染、切片,有效减轻服务器处理压力,减少网络负载和响应延迟,但瓦片数据量庞大,磁盘存储碎片化,影响IO性能,数据可迁移性差,无论是数据备份、迁移或是恢复都耗时漫长。该文设计实现了一种新的基于文件数据库的瓦片存储方案,并将分布式缓存系统Memcached作为缓存支持集成在方案中,不仅克服了传统瓦片储存的缺陷,还在性能方面取得了优异的表现,是构建高性能瓦片地图服务的有益尝试。  相似文献   

3.
我国近期移动地图与互联网地图发展综述   总被引:1,自引:0,他引:1  
我国移动地图与互联网地图逐渐成为地理信息与电子地图应用的主流趋势.该文从地图数据的组织与传输机制、可视化技术、在线地图服务以及导航各行业拓展应用等方面,总结了我国近期移动与互联网地图的研究进展,点评了目前发展中存在的若干问题,结合我国实际情况展望了其发展前景.  相似文献   

4.
地图可视化研究   总被引:25,自引:6,他引:19  
建立在计算机技术基础上的地图可视化是现代地图学的核心内容之一。文章从分析地图可视化的含义出发,提出了地图可视化研究的一个基本框架,同时简要分析了地图可视化的特点。认为地图可视化的主要研究领域有:可视化变量研究、可视化分类研究、时空数据结构研究、视觉感受与视觉效果研究、虚拟现实研究、空间认知与信息传输研究等 6个方面。最后,就北京地区地形三维可视化实践作了简单介绍。  相似文献   

5.
近年来随着计算机技术的发展,特别是增强现实技术的出现,使纸质地图的“增强”表达和交互分析成为可能。文章探讨了基于增强现实技术的纸质地图增强表达与交互分析流程方法,认为纸质地图增强表达和交互功能的关键技术在于:纸质地图标识的计算机识别,增强地图的空间匹配方法,增强地图的显示和交互方法;同时通过实验研发了原型系统并予以实现。利用增强现实技术扩展了纸质地图的可视化表达方法,把丰富的地理信息和纸质地图结合起来,打破了传统地图可视化的静态表现形式,提供了丰富的人机交互方式,能增强人对地理信息的多维动态感知能力,也增强补充了地图对现实世界的描述。  相似文献   

6.
地貌演化等地表过程的分析模拟实时产生系列地形数据,该动态过程的可视化对性能要求较高,传统基于预处理的方法计算量大、绘制延迟明显。面向大规模动态地形可视化,提出一种LOD预处理与实时更新相结合的混合调度技术,基于场景图对动态地形LOD建模与组织,建立多线程模型实现地形瓦片的动态更新和绘制。对于每次迭代计算产生的新地形,该方法以LOD瓦片的动态调度替代传统的静态预处理方法,与地表过程计算同步更新瓦片,且仅重新计算和渲染当前视域和分辨率下地形发生变化的局部瓦片,通过LOD的局部动态更新避免可视化数据的全局重新生成,显著降低过程模型计算和结果更新对渲染过程的影响,提高整体的可视化性能。  相似文献   

7.
针对目前三维仿真城市地图展示中单一视角因视线遮挡造成信息丢失的问题,提出了一种多视角三维仿真地图方法,即通过多个可以互相切换的视角对三维仿真城市地图数据进行发布与展示,多视角三维仿真地图具有信息量大、色彩鲜明、形象立体的优点。该文在分析多视角三维仿真地图数据的基础上,给出了数据组织模型,提出了三维仿真地图的多视角逻辑坐标与地理坐标的转换方法,实现了多视角三维仿真城市地图的可视化。  相似文献   

8.
地图数据缩编更新的模式分类与选择   总被引:4,自引:0,他引:4  
地图数据缩编更新模式是缩编更新技术流程设计及软件模块开发的基础。根据缩编和更新对象的不同归纳了缩编更新的4种模式,结合当前地图自动综合理论技术水平与数据组织管理现状,认为现阶段最合理的模式为新旧数据叠加缩编更新模式。基于该模式分析道路数据缩编更新的技术流程并开发了相应的软件模块,应用于国家1∶5万地理信息系统中道路数据的更新,从而验证了该模式的可行性。  相似文献   

9.
为解决LBS技术中组件式地理信息服务在车辆监控应用中研发成本和应用门槛较高的问题,基于第三方地图服务,研究分别从数据层、中间处理层与用户交互层出发,实现坐标系统转换、空间数据筛选与图形叠加等监控数据地图可视化关键技术,将数据层中不同源空间数据筛选转换成用户层中图形可视化交互信息。研究实现实时位置追踪与车辆行驶轨迹等基础功能,验证了监控数据地图可视化技术的可行性;并测试空间数据筛选技术的有效性,数据筛选率最高为30%。  相似文献   

10.
海量栅格地理数据的组织与调度   总被引:2,自引:0,他引:2  
针对目前海量栅格地理数据量大、结构复杂且难于管理与维护的现状,通过分析传统金字塔模型中瓦片的划分及编码方式,提出多金字塔混合组织模型,即在一个主体金字塔中,可任意包含多个子金字塔,各子金字塔模型相互独立且可部署在不同主机,从而便于数据独立制作与管理。分析子金字塔的标识及其瓦片编码,在数据组织的基础上,讨论栅格数据在显示过程中位于不同数据组织模型及不同操作下的具体调度方式。  相似文献   

11.
Visualizations of flood maps from simulation models are widely used for assessing the likelihood of flood hazards in spatial planning. The choice of a suitable type of visualization as well as efficient color maps is critical to avoid errors or bias when interpreting the data. Based on a review of previous flood uncertainty visualization techniques, this paper identifies areas of improvements and suggests criteria for the design of a task-specific color scale in flood map visualization. We contribute a novel color map design for visualizing probabilities and uncertainties from flood simulation ensembles. A user study encompassing 83 participants was carried out to evaluate the effects of this new color map on user’s decisions in a spatial planning task. We found that the type of visualization makes a difference when it comes to identification of non-hazardous sites in the flood risk map and when accepting risks in more uncertain areas. In comparison with two other existing visualization techniques, we observed that the new design was superior both in terms of task compliance and efficiency. In regions with uncertain flood statuses, users were biased toward accepting less risky locations with our new color map design.  相似文献   

12.
Along with the advances in computer sciences in recent years, visualization has been developed to embrace new functions. The electronic map in a spatial information visualization system is an electronic tool of human spatial cognition and has more advantages in supporting human spatial cognition than a printed map. Investigations on the ability of human spatial cognition are increasingly drawing attention of cartographers. In this background, map spatial cognition research is attached importance to cartographers again. Cognition-based visualization systems are intelligent systems that serve human spatial cognition efficiently. Developing adaptive multi-perspective visualization systems of spatial information as one kind of these systems is a main goal of our research. This paper discusses the necessity and the characteristics of map spatial cognition research. The cognitive issues involved in spatial information visualization and major contents of cognitive research in the design of adaptive visualization system are presented. Finally, the experimental methods of electronic map visual cognition are introduced.  相似文献   

13.
Simulation and subsequent visualization in a network environment are important to glean insights into spatiotemporal processes. As computing systems become increasingly diverse in hardware architectures, operating systems, screen sizes, human–computer interactions and network capabilities, effective simulation and visualization must become adaptive to a wide range of diverse devices. This paper focuses on the optimization of simulation and visualization analysis of the dam-failure flood spatiotemporal process for diverse computing systems. First, an adaptive browser/server architecture of the dam-failure simulation application was designed to fill the hardware performance and visualization context gap that exists within diverse computing systems. Second, a data flow and an optimization method for multilevel time-series flood data were given to provide more support to network simulation, visualization and analysis on diversified terminals. Finally, a user interaction friendly and plugin-free prototype system was developed. The experiment results demonstrate that the methods addressed in this paper can cope with the challenge in simulation, visualization and interaction of a dam-failure simulation application on diversified terminals.  相似文献   

14.
15.
中国电子地图发展中的可视化问题   总被引:2,自引:0,他引:2  
1IntroductionSpatial data can be visualized and explored in various ways. Developments in hardware and software have led to and will surely continue to stimulate novel methods for visualizing spatial data and creation of electronic atlas information syste…  相似文献   

16.
体绘制技术在地学3D GIS 可视化中的应用研究   总被引:1,自引:0,他引:1  
体绘制技术是目前科学计算可视化研究的一个重要组成部分,对地质体内部属性分布的可视化有重要意义。该文针对地学研究中几何建模和属性建模同样重要的特点,基于一种矢栅一体化的混合数据模型,对地质体表面采用三角面片描述几何形状,对地质体内部采用基于八叉树的自适应网格剖分技术描述内部属性特征。对网格剖分后的体数据,采用体元投射的体绘制技术进行地质体内部属性可视化,显示出很好的效果,具有实际应用意义。  相似文献   

17.
In this paper, we discuss the development of electronic atlas in China, with focus on the issues of visualization. We particularly categorise this development into four periods, and then analyse the characters in each period and discuss the visualization issues. The four periods are highlighted: 1) Infant period (<1990) characterized as computer assisted mapping with products of screen maps; 2) Starting period (1991-1995) characterized as object-oriented mapping with products of interactive maps/atlases; 3) Advancing period (1996-2000) characterized as integrated mapping with products of multimedia cartographic maps; 4) New era (> 2001) characterized as web mapping and adaptive map design with products of Internet maps and atlas as well as adaptive maps. It is obvious that the development follows the logical way from static to dynamic, and even real time visualization, from single user to multiple users, from presentation to exploration for effective communication and knowledge construction. Current research and development projects are focused on customisation of atlas information systems for real-time tasks, Internet operability, small displays and mobile environments. The major challenges involved in each of such customisation processes are identified and commented in relation to the further development of visualization.  相似文献   

18.
The recently introduced adaptive composite map projection technique changes the projection to the geographic area shown on a map. It is meant as a replacement for the commonly used web Mercator projection, which grossly distorts areas when representing the entire world. The original equal-area version of the adaptive composite map projection technique uses the Lambert azimuthal projection for regional maps and three alternative projections for world maps. Adaptive composite map projections can include a variety of other equal-area projections when the transformation between the Lambert azimuthal and the world projections uses Wagner’s method. To select the most suitable pseudocylindrical projection, the distortion characteristics of a pseudocylindrical projection family are analyzed, and a user study among experts in the area of map projections is carried out. Based on the results of the distortion analysis and the user study, a new pseudocylindrical projection is recommended for extending adaptive composite map projections. The new projection is equal-area throughout the transformation to the Lambert azimuthal projection and has better distortion characteristics then small-scale projections currently included in the adaptive composite map projection technique.  相似文献   

19.
Abstract

This paper describes a new joint Dutch research initiative ‘GIS-cartography’, combining the research efforts of the cartographers of Utrecht University, Delft University of Technology and the International Institute for Aerospace Survey and Earth Sciences (ITC) in Enschede. The research initiative focuses on the quantification and visualization of data quality, which will be placed in the context of providing automated visual decision support in specific map use strategies. As these map use strategies can only be performed if the relevant cartographic images can be created, studies of both physical access to the data, user interfaces and the provision of sufficient support to allow the user to understand and to derive sensible conclusions from the data are included in the project. Before modules automatically visualizing data quality can be implemented, data documentation, standardization and integration have to be effected, therefore these issues are also covered.  相似文献   

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