利用ArcGIS转换HPD源数据库中航海物标空间数据   总被引：2，自引：0，他引：2  

李颖  徐进  李家  张安民  卫国兵  杨龙 《测绘科学》2013,38(5):141-142,145

我国海事测绘部门自2008年开始引进CARIS HPD海道产品数据库系统,其空间数据共享转换方法一直是无法解决的难题。本文从CARIS HPD物标源数据库和Shapefile文件数据存储结构入手,详细阐述了CARIS HPD航海物标源数据空间信息获取方法和ArcGIS Shapefile文件生成方式,并提出将物标空间数据从HPD源数据库转换至Shapefile文件的解决方案。  相似文献   

Mathematical basis for large scale GIS and terrestrial digital products     

Hu Yuju  Hu Peng  Wu Yanian  Yang Chuanyong  Li Guojian 《地球空间信息科学学报》2013,16(3):35-41

The problem of spatial mathematical basis has been encountered by both large scale GIS and spatial digital products theoretically and practically. It is also a basic problem in the development of the whole geo-information science. After analyzing the status quo and the limitations of the space mathematical base of GIS, this paper points out definitely that the geodetic coordinate system is uniform, which can show the location of any point of the global exactly and uniquely in form of (B, L, H) and is the most proper reference system of largescale GIS and Digital Earth. Moreover, this paper also puts forward a set of practical model of the standard “map projection”. Finally, this paper introduces a DRG system based on this model.  相似文献   

Seven possible states of geospatial data with respect to map projection and definition: a novel pedagogical device for GIS education     

Steven E. Greco 《地球空间信息科学学报》2013,16(4):288-293

ABSTRACT

Conceptually, the theory and implementation of “map projection” in geographic information system (GIS) technology is difficult to comprehend for most introductory students and novice users. Compounding this difficulty is the concept of a “map projection file” that defines map projection parameters of geo-spatial data. The problem of the “missing projection file” appears ubiquitous for all users, especially in practice where data is widely shared. Another common problem is inadvertent misapplication of the “Define Projection” tool that can result in a GIS dataset with an incorrectly defined map projection file. GIS education should provide more guidance in differentiating the concepts of map projection versus projection files by increasing understanding and minimizing common errors. A novel pedagogical device is introduced in this paper: the seven possible states of GIS data with respect to map projection and definition. The seven possible states are: (1) a projected coordinate system (PCS) that is correctly defined, (2) a PCS that is incorrectly defined, (3) a PCS that is undefined, (4) a geographic coordinate system (GCS) that is correctly defined, (5) a GCS that is incorrectly defined, (6) a GCS that is undefined, and (7) a non-GCS. Recently created automated troubleshooting tools to determine a missing map projection file are discussed.  相似文献   

Unification and harmonization in true color image city map     

Zhao Xi  Pang Xiaoping  Zhang Shengli  Zhang Xiang 《地球空间信息科学学报》2013,16(1):75-78

True color image city map is a sort of new-style map which combines the high resolution image and map symbols and shows both advantages in visualization. At the same time, the map unification and harmonization should be taken into account during the design process, since some visual conflicts appear when map symbols overlaid on the true color image. The objective of this research is to explore the rules in the process of true color image city map design based on chromatic and aesthetic knowledge. At the end, taking the Image Atlas of Guangzhou as an example, image color adjustment, road network presentation, and symbol designing issues will be discussed in the application.  相似文献   

Advected fields in maps: II. Dynamo action in the stretch–fold–shear map     

Andrew D. Gilbert 《地球物理与天体物理流体动力学》2013,107(3):241-269

The growth of magnetic field is considered in the stretch–fold–shear map in the limit of weak diffusion. Numerical results are given for insulating, perfectly conducting and periodic boundary conditions. The resulting eigenvalue branches and magnetic fields are related to eigenvalue branches for perfect dynamo action, obtained for zero diffusion using a complex variable formulation.

The effect of diffusion on these perfect dynamo modes depends on their structure, growth rate and the diffusive boundary conditions employed. In some cases, the effect of diffusion is a small perturbation, giving a correction going to zero in the limit of weak diffusion, with a scaling exponent given analytically. In other cases weak diffusion can entirely destroy a perfect dynamo branch. Diffusive boundary layers can also generate entirely new branches.

These different cases are elucidated, and within the framework of the asymptotic approximations used (which do not constitute a rigorous proof), it is seen that for all three boundary conditions employed, the stretch–fold–shear map is a fast dynamo.  相似文献   

Spatial and temporal change in landslide hazard by future climate change scenarios using probabilistic-based frequency ratio model     

Lee Moung-Jin  Song Won-Kyong  Won Joong-Sun  Park Inhye 《国际地球制图》2013,28(6):639-662

The aims of this study were to apply, verify and compare a frequency ratio model for landslide hazards, considering future climate change and using a geographic information system in Inje, Korea. Data for the future climate change scenario (A1B), topography, soil, forest, land cover and geology were collected, processed and compiled in a spatial database. The probability of landslides in the study area in target years in the future was then calculated assuming that landslides are triggered by a daily rainfall threshold. Landslide hazard maps were developed for the two study areas, and the frequency ratio for one area was applied to the other area as a cross-check of methodological validity. Verification results for the target years in the future were 82.32–84.69%. The study results, showing landslide hazards in future years, can be used to help develop landslide management plans.  相似文献   

关于国土资源“一张图”建设的思考     

屈晓波  赵根 《国土资源信息化》2013,(4):12-15

国土资源＂一张图＂建设作为国土资源信息＂十二五＂的重要工作,目前正在全国各级国土资源管理部门中如火如荼的开展,但对于国土资源＂一张图＂的定义和建设方法,全国并无统一的界定和设计,本文在对目前全国各地国土资源＂一张图＂建设进行综合分析的基础上,提出了作者自己关于国土资源＂一张图＂建设的思考。  相似文献   

Do choropleth maps linked with parallel coordinates facilitate an understanding of multivariate spatial characteristics?     

Tomasz Opach  Jan Ketil Rød 《制图学和地理信息科学》2013,40(5):413-429

Our study has three objectives. We want to investigate (1) whether choropleth maps linked with parallel coordinates help people understand the locations of vulnerable places and the factors making these places vulnerable, (2) whether sparklines that imitate the polylines from a parallel coordinate plot support the understanding of the information provided in that plot, and (3) whether a multiple-view geovisualization approach might be intuitive and useful also for nonexperts. Although we base our work on the functionalities available in the tool called ‘ViewExposed,’ we intend to outline more general conclusions on whether multiple linked views facilitate the understanding of multivariate spatial characteristics. An empirical study with 53 individuals was conducted to obtain insights on these objectives. Our task-based assessment considered the ways in which participants understood the dynamic linking capabilities. Some of the key findings are as follows: (1) even nonexpert users are able to use parallel coordinates linked with choropleth maps; however, only those with extensive inference-making abilities will do so efficiently; (2) parallel coordinates sparklines work as an independent component facilitating the understanding of multivariate data; and (3) the intuitive nature of a multiple-view geovisualization tool is not enough to encourage people to use it.  相似文献   

An experimental analysis of three methods for highlighting colorful pictographic symbols     

Jari Korpi  Andreas Hall  Paula Ahonen-Rainio 《制图学和地理信息科学》2013,40(1):27-36

Highlighting is one of the key functionalities of any interactive visualization environment. Yet, there is little research on highlighting methods. This article focuses on highlighting of colorful pictographic symbols. Three strategies for highlighting were tested by implementing three highlighting methods that were suggested suitable in the literature on attention, perceptual grouping, and motion detection. An experimental design measuring response times and accuracy was used and subjective opinions were collected. The three available strategies for applying the highlighting effect to a subset of visually salient (i.e., colorful) symbols are: (1) to decrease the saliency of the non-highlighted symbols, (2) to increase the saliency of the highlighted symbols, and (3) to add a connecting element for grouping the highlighted symbols. Of these strategies, adding a connecting element was found to be the least efficient based on the response times, whereas both methods for tuning the saliency difference between the highlighted and non-highlighted symbols were found to be equally efficient. However, decreasing the saliency of the non-highlighted symbols was clearly preferred in the subjective evaluation.  相似文献   

互联网地图初探     

刘全义  王德峰  丁林可  王娟 《地理空间信息》2013,(3):158-159

以"数字河南"公众地图网为例,深入分析和探讨了互联网地图的现状及建设思路,为加强互联网地图数据库及其数据的管理,推进数据完整、信息规范的互联网地图数据库建设,提升互联网地图管理工作的水平,满足社会对互联网地图信息需求,提供了可行性技术依据。  相似文献