粤西沿海震动图的生成和研究

震动图是描绘地震产生的地面运动和可能破坏情况的有效工具,主要包括峰值地面速度(PGV)等值线图、峰值地面加速度(PGA)等值线图和仪器烈度分布图等.基于华南数字地震台网记录到的2010年7月9日MS3.7级阳江地震的数据资料,利用SAC和GMT软件从记录到的地震波形数据提取地面运动参数,生成了PGV和PGA等值线图,并...     

提高城市大比例尺地形图转换到CGCS2000精度的探讨

针对在进行城市坐标系中的大比例尺地形图转换到CGCS2000中,采用统一区域坐标转换模型进行整体转换,将会使地形图在转换后的精度不能满足成图精度要求,提出了通过对区域内的所有控制点进行兼容性检测,剔除不能满足精度要求的点后,对所有控制点构建TIN,然后采用仿射变换模型分块对各三角形内的大比例尺地形图进行转换,从而实现提...     

MicroStation在数字专题地图中的应用

MicroStation制图系统不仅具有良好的图形化作业环境,而且能够管理图形的各种数据信息。它有着丰富而强大的专题地图制作功能以及性能稳定的二次开发环境,从根本上改善和优化了传统的地图生产工艺,实现了数字地图的出版与空间数据生产一体化,从而提高了制图效率和现有数据利用率。     

Narrative Cartography: From Mapping Stories to the Narrative of Maps and Mapping

Abstract

This paper provides an overview of the multiple ways of envisioning the relationships between maps and narratives. This is approached from a map making perspective. Throughout the process of editing this special issue, we have identified two main types of relationships. Firstly, maps have been used to represent the spatio-temporal structures of stories and their relationships with places. Oral, written and audio-visual stories have been mapped extensively. They raise some common cartographic challenges, such as improving the spatial expression of time, emotions, ambiguity, connotation, as well as the mixing of personal and global scales, real and fictional places, dream and reality, joy and pain. Secondly, the potential of maps as narratives and the importance of connecting the map with the complete mapping process through narratives is addressed. Although the potential of maps to tell stories has already been widely acknowledged, we emphasize the increasing recognition of the importance of developing narratives that critically describe the cartographic process and context in which maps unfold - the core idea of post-representational cartography. Telling the story about how maps are created and how they come to life in a broad social context and in the hands of their users has become a new challenge for mapmakers.     

不同Klobuchar模型参数的性能比较

对于GPS单频用户而言,电离层延迟是最重要的误差来源之一。GPS系统使用Klobuchar模型对电离层延迟进行改正,其改正数从370组常数中选取。目前全球分布的GPS测站可以获得高精度的全球电离层监测结果,GPS为什么不发播采用实测数据计算得到的Klobuchar模型参数呢？本文针对这一问题进行分析。首先对欧洲定轨中心CODE提供的全球电离层图GIM预报COPG电离层进行精度评估,然后根据COPG电离层进行Klobuchar模型参数拟合并利用IGS提供的事后高精度电离层图进行精度分析,最后将不同的电离层模型参数应用于单点定位以评估其对单频用户的影响。分析结果表明：受8参数的Klobuchar模型本身结构限制,采用全球实测数据计算的电离层模型参数与导航电文中发播的电离层模型精度相当,为55%左右。而仅采用地磁纬度45oS以北的数据拟合得到的模型参数,其电离层改正精度有明显提升,可达65%左右,但其对单频用户定位精度改善不明显。本文研究结果为我国全球电离层建模提供参考。     

基于 ArcGIS 的电子地图数据制作研究

以基于ArcGIS的电子地图制为研究对象,探讨了在地理信息公共服务平台中进行电子地图制作的技术流程及方法,详细阐述了电子地图制作中的数据提取,数据组织与电子地图数据展示中的相关关键技术,实现了地理信息公共服务平台在线地图展示、浏览和标注。     

AutoCAD VBA在地形图批处理中的应用

AutoCAD VBA是一种简单易上手的编程工具,通过设计批处理程序能显著提高作业效率。本文基于AutoCAD VBA平台进行程序设计,针对地形图生产中九宫格修改的具体问题,编程进行批量修改,在实践基础上形成一种基于AutoCAD VBA的通用地形图批处理方法。实践证明,该方法能明显提高测绘生产部门的工作效率。     

城镇化区域变迁轨迹与地形图使用情况关系探讨

地形图广泛应用在城市规划、城市市政、轨道交通、城市建筑等领域,是开展设计和施工工作重要的参考资料。本文通过研究,将北京市地形图服务库使用情况数据转换到空间数据库,利用统计分析和制图技术,绘制了北京市近十年地形图使用情况数据分布图,同时结合北京城市建设历史情况进行对比,发现地形图使用情况真实反映了城市建筑时间节点的历史特点,一定程度上记录了北京城镇化区域变迁轨迹。     

Placing dots in dot maps

Dot mapping is a cartographic representation method to visualise discrete absolute values and their spatial distribution. To achieve this, dots equal in size and represented value are used. According to the dot value, a certain number of dots are used to depict a data value. These dots usually form dot clusters. The data value needs to be rounded to a multiple of the dot value. It is possible to roughly determine the visualised data value by counting the dots and multiplying this number with the dot value. As there are many parameters – dot size, dot value, map scale – to consider when designing a dot map, the manual way is very complex and time consuming. This paper presents a method to automatically create a dot representation of a dot map from given statistical data that needs no cartographic expertise. The dot representation may be combined with other elements, such as a topographic background, to form a complete map. So the algorithm can easily be integrated into the map design process. The paper refines the basic approach of automated dot mapping published earlier. The dot placement and arrangement have been improved compared to the basic method.     

Excel与MapGIS结合在地质制图中的应用

采用MapGIS软件绘制地质图件时,经常遇到需要批量输入点线等数据问题,如果直接逐个输入,不但效率低下,且容易输错,利用Excel的编制函数功能编写MapGIS明码文件,来说明如何实现MapGIS点线文件的批量输入,使地质图件的绘制更加快速、准确、高效。