多投影间地图投影变换实现的途径与优化

针对多种地图投影间自由变换的需求,综合对比地图投影变换的主要方法及其特点,该文认为反解变换是解决多种投影间投影变换的最佳途径。以此为基础,具体探讨了地图投影变换计算机的实现的主要过程,讨论了地图投影体系、投影参数、算法优化和误差控制等投影变换计算机实现中的关键问题。     

多投影间地图投影变换实现的途径与优化

针对多种地图投影间自由变换的需求 ,综合对比地图投影变换的主要方法及其特点 ,该文认为反解变换是解决多种投影间投影变换的最佳途径。以此为基础 ,具体探讨了地图投影变换计算机实现的主要过程 ,讨论了地图投影体系、投影参数、算法优化和误差控制等投影变换计算机实现中的关键问题     

浅析地图投影的选择与应用

地图投影作为地图学的重要组成部分和建立地图的数学基础,其投影的选择至关重要,本文通过研究和探讨地图投影理论,并结合本人工作实际中曾遇到的有关投影问题,浅析地图投影的数学基础和地图投影的选择与应用中应注意的技术问题,以求为国民经济建设提供更为准确、优质的测绘服务保障。     

海洋小比例尺地图精确测量及计算方法

针对传统的欧式测量方法在海洋小比例尺地图长度、面积等计算时存在精度差的问题,通过对WGS1984投影、墨卡托投影、兰勃托投影和阿尔伯斯投影等特性的研究,利用ArcEngine技术实现海洋小比例尺地图投影的精确测量及计算,论述在不规则地球椭球体下如何精确量算海洋距离、面积等信息,为我国海洋资源探测和军事战略方面提供基础服务.     

二战期间美国地缘战略空间观念变迁 ——基于地图投影的视角

在地图投影变换影响下,得益于多样化的地图服务,二战期间美国地缘战略空间观念经历了从孤立主义向干涉主义的转变,推动了美国的参战与具体战略展开。这一空间逻辑在战时地图投影的选择上表现为从圆柱投影下的二维“矩形世界”向等距方位投影下的“圆形世界”和正射投影下的三维“球体世界”“鸟瞰世界”转变,折射出空中时代下的全球一体观。通过不同投影下“地图空间”的调整,二战期间美国地缘战略空间观念逐渐接近现实地球空间,这无疑增强了美国参战的合理性和战略决策的正确性。作为认知话语和实践话语的统一,地图投影通过地图服务反映并参与到了二战的地缘政治发展进程。伴随着美国地缘战略空间观念的变迁,美国也由此从世界舞台的边缘走向国际体系的中心。在当前中国和平崛起和全球地缘调整的大背景下,地图投影创新也为今后的地缘关系研究提供了诸多启示。     

南极地区常用地图投影及其应用

南极地区常用的地图投影方式有 :极方位立体投影、横轴墨卡托投影、兰伯特正形圆锥投影等三种等角投影。本文在介绍了所有等角投影应满足的一般条件的基础上 ,分别详述了上述三种投影在南极地区的具体应用。并对卫星影像的投影作了探讨。     

地图投影与地缘政治理论构建——以麦金德地缘政治思想为例

地缘政治理论的提出和发展深刻烙印了地图的影响。在地缘政治发展史中,不同地图投影既服务于各思想家的理论提出,也深入到各思想家在不同时期对自身理论的动态修正。地图投影到底是如何参与到地缘政治理论构建过程中的?本文在既有地缘政治地图研究的基础上,从空间性和文本性两大地图基本属性出发,通过阐释并沟通地图的空间分析与话语分析功能,探讨地图投影与地缘政治理论构建间的关系。一方面,地图投影变形抽象后的心象地图框架为构建地缘政治理论提供了空间依托;另一方面,地图投影通过地图变形在复杂情境中聚集了丰富的文本性含义。在地图投影各层次文本性的互文（互补性叙事）下,新的地图话语得以产生并渗透进心象地图,具象式推动了地缘政治理论核心概念的生成和逻辑关系的构建。综合考虑麦金德的地图观影响,本文对麦金德“心脏地带”地缘政治思想变迁各阶段（1904年、1919年、1943年）地图投影透视的分析验证了该关系框架的解释力。这启示该分析框架在其他地缘政治理论研究中的潜在适用性,更期待在百年变局和复兴全局等交织下的复杂情境中,基于地图投影创新互文下的中国地缘政治理论构建。     

地图编制与应用

P282.12007043672中国海岸带专用地图投影设计=Map projection design forChina coastal zone/韩雪培,李满春…∥测绘学报.—2006,35(4).—395~399地图投影是各类海岸带信息的空间定位框架要素之一,通过对目前我国海岸带常用的各种地图投影现状分析,设计并实现全国海岸带专用投     

《福建省自然地图集》的编制特点

本文介绍了《福建省自然地图集》的有关幅面设计、地图投影、内容安排几个方面的特点,并阐述了图集中各图组通过地图符号、色彩设计等内容,向读者传递丰富自然资源信息的特点。     

一本简明的高校教学用书——介绍孙达、蒲英霞编著的《地图投影》

代表地球形状的地球椭球面(或球面)是不可展曲面,而地图通常是表示在平面上,在解决地球曲面与地图平面的矛盾中产生的一门学科———地图投影,是用数学方法将地球曲面上的经纬线描写到平面或可展曲面上建立对应的经纬网以确定地面物体的地理位置。地图投影既是一门独立的学科,同时又是地图制图学的重要组成部分,所以它从地图的生产到使用都是不可缺少的数学基础和地图要素。由南京大学城市与资源学系孙达、蒲英霞编著的《地图投影》一书,最近已由南京大学出版社出版发行了。两位作者都先后在该系承担地图投影课程的教学任务,其中孙达教授来南京大学任教之前在总参测绘局从事地图编辑工作十多年,对投影的实际运用和后来的教学实践都有着丰     

A new pseudocylindrical equal-area projection for adaptive composite map projections

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.     

The Equal Earth map projection

The Equal Earth map projection is a new equal-area pseudocylindrical projection for world maps. It is inspired by the widely used Robinson projection, but unlike the Robinson projection, retains the relative size of areas. The projection equations are simple to implement and fast to evaluate. Continental outlines are shown in a visually pleasing and balanced way.     

A compromise aspect-adaptive cylindrical projection for world maps

There are two problems with current cylindrical projections for world maps. First, existing cylindrical map projections have a static height-to-width aspect ratio and do not automatically adjust their aspect ratio in order to optimally use available canvas space. Second, many of the commonly used cylindrical compromise projections show areas and shapes at higher latitudes with considerable distortion. This article introduces a new compromise cylindrical map projection that adjusts the distribution of parallels to the aspect ratio of a canvas. The goal of designing this projection was to show land masses at central latitudes with a visually balanced appearance similar to how they appear on a globe. The projection was constructed using a visual design procedure where a series of graphically optimized projections was defined for a select number of aspect ratios. The visually designed projections were approximated by polynomial expressions that define a cylindrical projection for any height-to-width ratio between 0.3:1 and 1:1. The resulting equations for converting spherical to Cartesian coordinates require a small number of coefficients and are fast to execute. The presented aspect-adaptive cylindrical projection is well suited for digital maps embedded in web pages with responsive web design, as well as GIS applications where the size of the map canvas is unknown a priori. We highlight the projection with a height-to-width ratio of 0.6:1, which we call the Compact Miller projection because it is inspired by the Miller Cylindrical projection. Unlike the Miller Cylindrical projection, the Compact Miller projection has a smaller height-to-width ratio and shows the world with less areal distortion at higher latitudes. A user study with 448 participants verified that the Compact Miller – together with the Plate Carrée projection – is the most preferred cylindrical compromise projection.     

雪龙船实时航迹图中的技术处理方法

采用新编《系列世界地图》成果,结合GIS和计算机网络技术,于2004年11月首次实现了我国南极考察“雪龙”船航迹的网上实时跟踪服务。本文详细论述了“实时航迹图”的投影转换原理、图幅坐标与屏幕坐标的映射、航迹线剪裁、网上建立“实时航迹图”及利用可视化组件实现网上“实时航迹图”web应用几个关键技术问题,并给出了解决这些问题的具体方法。     

Graphical design of world map projections

The design of new map projections has up until now required mathematical and cartographic expertise that has limited this activity to a small group of specialists. This article introduces the background mathematics for a software-based method that enables cartographers to easily design new small-scale world map projections. The software is usable even by those without mathematical expertise. A new projection is designed interactively in an iterative process that allows the designer to graphically and numerically assess the graticule, the representation of the continents, and the distortion properties of the new projection. The method has been implemented in Flex Projector, a free and open-source application enabling users to quickly create new map projections and modify existing projections. We also introduce new tools that help evaluate the distortion properties of projections, namely a configurable acceptance index to assess areal and angular distortion, a derived acceptance visualization, and interactive profiles through the distortion space of a projection. To illustrate the proposed method, a new projection, the Cropped Ginzburg VIII projection, is presented.     

南大洋海冰影像地图投影变换与瓦片切割应用研究

南大洋海冰分布是南极考察过程中影响破冰船航行的重要因素,也是南极研究的重要内容之一。目前国际上不同机构发布的南大洋海冰分布图,大多是球面投影,不能直接用于主流的瓦片地图发布。将极方位立体投影海冰图转换为目前主流的网络墨卡托投影地图,并利用合适的图像重采样方法,按照不同级别比例尺进行瓦片切割和编号存储,最终实现海冰影像地图的发布共享是本文的主要研究内容。笔者对不同的图像重采样方法进行了比较,分析了最邻近点采样方法、双线性内插和双三次卷积重采样方法的优劣,针对本文的研究优选双线性内插方法进行影像地图瓦片的切割,并最终叠加融合在Google地图上,实现了Google底图、准实时海冰影像图与破冰船走航位置的集成显示,为雪龙船的冰区航行提供了重要的数据支撑。     

Volume 111 Index

Abstract

Concepts related to alternative map projections can be difficult to explain to students given the diversity and complexity of available projections. Students frequently have trouble understanding how distortions caused by the choice of a projection can affect map readability and comprehension. Programs available for personal computers now provide geography and cartography instructors with a method for interactively educating students concerning the distortions associated with alternative map projections. Such software can be incorporated into laboratory assignments in introductory geography courses or in more advanced courses that deal with map design or thematic cartography.     

Quasi indicatrix approach for distortion visualization and analysis for map projections

Tissot’s indicatrix or ellipse of distortion is a diagram that is the projection of an infinitesimal circle on the original surface. It is normally an ellipse of which elongation depends on the amount of distortion caused by map projection. It provides a medium for analyzing existing projections and developing new ones. The ellipse can be scaled and depicted on the map for visualization purposes. This paper presents an alternative approach, in which the projection of a finite small circle on the sphere is used. Its projection is normally an ellipse that can be very close to Tissot’s indicatrix, and is called quasi indicatrix, here. Its parameters can be derived from the forward projection equations without using partial derivatives. Therefore, it is a useful and practical approach from a programmer’s point of view. The quasi indicatrix approach is also numerically tested on Aitoff–Hammer projection with a set of points. The indicatrix parameters obtained by using this approach deviate 0.5% from the ground truths at most, being the average less than 0.2%.