基于3维的基础测绘成果客户选图服务系统研究

探讨了GeoGlobe3维GIS技术在基础测绘成果客户选图服务中的应用,主要包括系统框架设计和具体功能。     

基于移动终端的位置地图服务研究综述

位置信息服务已经成为目前现代服务业的重要构成之一,也是未来移动应用的发展方向之一。作为位置信息服务中的位置地图成为支撑位置服务业发展的关键。本文重点对位置地图服务中涉及的移动终端、移动地理信息和移动地图三个关键技术问题进行了研究分析,总结了目前研究中存在的问题,并提出了今后发展趋势和研究方向,为移动位置服务,尤其是移动位置地图的研究,提供重要的借鉴和参考。     

兵棋地图的演进与评述

兵棋是对作战过程进行逻辑推演研究和评估的军事科学工具,是作战模拟的一种重要方法和手段。兵棋地图作为兵棋的三大组成要素之一,其表达内容、表达方式及表达精度对兵棋推演的结果有着重要的影响。回顾兵棋地图的演进,有助于把握兵棋发展的历史脉络,加深对战场环境模拟的认识。以兵棋地图出现的时间为依据,将兵棋地图的演进过程分为三个阶段：原始兵棋地图阶段、经典兵棋地图阶段和现代兵棋地图阶段,并从表达内容、表达方式和表达精度三个方面对每个阶段的兵棋地图进行了分析。     

地质图数据坐标转换工作流程——以K51E011016铁岭县幅为例

为了加速2000国家大地坐标系的推广进程,中国地质调查局要求各地勘单位将其他坐标系下的地质图数据转换为2000国家大地坐标系。本文根据K51E011016（铁岭县幅）数据转换工作的一些经验和体会．总结了地质图数据转换的工作流程,希望本文对即将从事该项工作的同行们有所借鉴。     

Monitoring thickness and volume changes of the Dongkemadi Ice Field on the Qinghai-Tibetan Plateau (1969–2000) using Shuttle Radar Topography Mission and map data

Abstract

This paper presents the first measurement of multi-decadal thickness and volume changes (1969–2000) of the Dongkemadi Ice Field (DIF) in the Tanggula Mountains, central Qinghai-Tibetan Plateau, China, using multi-source remote sensing data. These include the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) acquired in February, 2000, a DEM generated by digitising analogue topographic maps from 1969, and Landsat ETM+ imagery from 2000. Digital glacier outlines and GIS-based processing were used to calculate an elevation difference map to evaluate the relative elevation error of these two DEMs over ice-free areas. This method was also used to identify regions of glacier elevation thinning and thickening corresponding to glacier mass loss and gain. Analysis of 67,520 points on flat grass and rock terrain surrounding the DIF, with a slope less than 25°, showed a mean elevation difference of –0.90 m and a standard deviation of 5.58 m. A thickness change error within ±6 m was estimated. Between 1969 and 2000, 76.51% of the whole DIF area appeared to be thinning while 23.49% showed thickening. The average glacier surface thinning was –12.58 m with a standard deviation of 18.29 m and the estimated volume loss was 1.17 km³. The standard deviation of volume change was 0.0006 km³ over the DIF. A thinning rate up to 0.41±0.194 m a^?1 or 0.038 km³ a^?1 for the volume loss was observed for the whole ice field, which seems to be evidence for the ongoing retreat of glaciers on the Qinghai-Tibetan Plateau. It was found that the spatial thickness change pattern derived from the remote sensing method was consistent with the thickness change results of the Small Dongkemadi Glacier (SDG) from field measurements. The estimated error of the annual thickness change rate was on the order of 5%. The relationship between elevation change and absolute glacier elevation over typical glaciers was also analysed, showing considerable variability. These changes have possibly resulted from increased temperature and decreased precipitation in this region.     

Blending Aggregation and Selection: Adapting Parallel Coordinates for the Visualization of Large Datasets

Abstract

Many of the traditional data visualization techniques, which proved to be supportive for exploratory analysis of datasets of moderate sizes, fail to fulfil their function when applied to large datasets. There are two approaches to coping with large amounts of data: data selection, when only a portion of data is displayed, and data aggregation, i.e. grouping data items and considering the groups instead of the original data. None of these approaches alone suits the needs of exploratory data analysis, which requires consideration of data on all levels: overall (considering a dataset as a whole), intermediate (viewing and comparing collective characteristics of arbitrary data subsets, or classes), and elementary (accessing individual data items). Therefore, it is necessary to combine these approaches, i.e. build a tool showing the whole set and arbitrarily defined subsets (object classes) in an aggregated way and superimposing this with a representation of arbitrarily selected individual data items.

We have achieved such a combination of approaches by modifying the technique of parallel coordinate plot. These modifications are described and analysed in the paper.     

Mastering the Niger. James MacQueen’s African Geography and the Struggle Over Atlantic Slavery

Abstract

Since the publication of the first waterway map in 1990, the Inland Waterways of Britain series has expanded to a total of twenty three individual maps, a national route planning map, the first ring atlas and a directory of the inland waterways which explores aspects of preservation, restoration and heritage. Many of the titles have featured in walking guides, directories, promotional literature and web sites. This paper outlines the development of the series from the first map, describing the maps themselves, tracking the evolution of production methodologies, defining marketing and sales strategies and discussing the decision-making processes behind the publication and introduction of new titles.     

Harveys and Walking Maps

Abstract

Geographical information is connected to everyday life in many ways. Web cartography has made geospatial data more available to the public. In the next few years, the average age of the population will be over 51 years, with more than 15% of the population over the age of 65 years. The fact that the senior population is increasing suggests that online mapping and map viewer design should be aware of the senior population’s visual restrictions, as well as restrictions of other potential map users, including colour-vision-impaired users. This paper describes the senior population’s visual restrictions that can be compared with colour-vision-impaired users and provides guidelines with regard to online mapping and map viewer design for this growing segment of the elderly population.     

An Empirical User Study for Measuring the Influence of Colour Distance and Font Size in Map Reading Using Eye Tracking

Abstract

An assessment of British responses to a pan-European questionnaire conducted during the summer of 2003.     

The National Archives and Public Records

Abstract

The article provides an overview of the huge cartographic holdings of The National Archives (TNA). It continues by outlining the procedures by which records are selected for permanent preservation by TNA.