Planning the Migration to OS MasterMap in the UK Legal Deposit Libraries

Abstract

This paper describes the process confronting the UK Legal Deposit Libraries of selecting a system architecture and hosting for their store of digital cartographic data for the nation. These institutions have a mission not only to collect the published output of the national mapping agency, Ordnance Survey, but also to make it accessible to the public and ensure, via sound archival practices, that it be available in perpetuity. Considerations include how other institutions and agencies are handling similar issues, software and hardware to support the new GML file format, hosting to serve the application and data to the six libraries, and methods of archiving and preservation.     

Framework for Entropy-based Map Evaluation

The automation of map design is a challenging task for both researchers and designers of spatial information systems. A main problem in automation is the quantification and formalization of the properties of the process to be automated. This article contributes to the formalization of some steps in the processes involved in map design and demonstrates how the Shannon information theory (Shannon and Weaver 1964) can be used to compute an evaluation index of a map, i.e., a parameter which measures the efficiency of the map. Throughout this article, the term "information" is mostly used in a narrow sense and the application of information theory is restricted to the syntactic level of cartographic communication. Information sources for map entropy computations are identified and elaborated on. A special class of map information sources are defined and termed "orthogonal map information sources". Further, a strategy to consider spatial properties of a map in entropy computations is presented. At the end of the article, some examples demonstrate how the channel capacity and other entropy related measures can be computed and used to control automated processes for map design or map generalization.     

Distinctive Recent Maps

Successful implementation of an intelligent system for automated map generalization requires formalization of cartographic principles that are, in many cases, only intuitively understood. Formalizing these principles requires acquisition and re-expression in the form of semantic nets, frames, production rules, or similar formalization methods. The various techniques for cartographic knowledge acquisition have been discussed on a theoretical basis; however, little empirical research has been conducted. This paper reports on empirical acquisition of cartographic knowledge by reverse engineering; that is, on trying to recapitulate decisions made on published documents or maps. The work is based on a computer-assisted multi-scale inventory of the Austrian National Topographic Map Series. Queries of the relational database, within which inventory data are stored, lead to the formulation of prototype production rules for modifying map symbols during automatic scale changes. Components of map generalization expressed in such rules include the selection behavior of settlement, transportation, and hydrographic objects, and the degree of simplification of settlement domains and building clusters. The acquired cartographic knowledge reveals quantitative relations between map elements and the changes in these relations that occur with scale transition. These insights can guide subsequent knowledge refinement using other acquisition methods. This paper provides, in addition, a conceptual framework by which other topographic map series may be compared at multiple scales.     

Use of Graph Theory to Support Map Generalization

In the generalization of a concept, we seek to preserve the essential characteristics and behavior of objects. In map generalization, the appropriate selection and application of procedures (such as merging, exaggeration, and selection) require information at the geometric, attribute, and topological levels. This article highlights the potential of graph theoretic representations in providing the topological information necessary for the efficient and effective application of specific generalization procedures. Besides ease of algebraic manipulation, the principal benefit of a graph theoretic approach is the ability to detect and thus preserve topological characteristics of map objects such as isolation, adjacency, and connectivity. While it is true that topologically based systems have been developed for consistency checking and error detection during editing, this article emphasizes the benefits from a map-generalization perspective. Examples are given with respect to specific generalization procedures and are summarized as a partial set of rules for potential inclusion in a cartographic knowledge-based system.     

Solving Space Conflicts in Map Generalization: Using a Finite Element Method

A finite element method was developed to handle conflicts during the generalization of maps. The method is holistic and solves conflict problems for the entire map surface simultaneously. When a generalized object changes size, the method immediately causes displacements in surrounding objects. Boundary constraints were introduced which make it possible to maintain the shape of objects, and simultaneously change the size of the objects. An iterative solution procedure for the Finite Element problem was shown to give solutions that better fulfill topological requirements than a direct solution of the problem.     

Spatial Knowledge Acquisition with Mobile Maps,Augmented Reality and Voice in the Context of GPS-based Pedestrian Navigation: Results from a Field Test

GPS-based pedestrian navigation systems have become increasingly popular. Different interface technologies can be used to communicate/convey route directions to pedestrians. This paper aims to empirically study the influence of different interface technologies on spatial knowledge acquisition in the context of GPS-based pedestrian navigation. A field experiment was implemented to address this concern. Firstly, the suitability of the evaluation methods in assessing spatial knowledge acquisition was analyzed empirically (focusing on the ability of differentiating “familiar” and “unfamiliar” participants). The suitable methods were then used to compare the influence of mobile maps, augmented reality, and voice on spatial learning. The field test showed that in terms of spatial knowledge acquisition, the three interface technologies led to comparable results, which were not significantly different from each other. The results bring some challenging issues for consideration when designing mobile pedestrian navigation systems.     

Representing Complex Geographic Phenomena in GIS

Conventionally, spatial data models have been designed according to object- or field-based conceptualizations of reality. Conceptualization of complex geographic phenomena that have both object- and field-like properties, such as wildfire and precipitation, has not yet been incorporated into GIS data models. To this end, a new conceptual framework is proposed in this research for organizing data about such complex geographic phenomena in a GIS as a hierarchy of events, processes, and states. In this framework, discrete objects are used to show how events and processes progress in space and time, and fields are used to model how states of geographic themes vary in a space-time frame. Precipitation is used to demonstrate the construction and application of the proposed framework with digital precipitation data from April 15 to May 22, 1998, for the state of Oklahoma, U.S.A. With the proposed framework, two sets of algorithms have been developed. One set automatically assembles precipitation events and processes from the data and stores the precipitation data in the hierarchy of events, processes, and states, so that attributes about events, processes, and states are readily available for information query. The other set of algorithms computes information about the spatio-temporal behavior and interaction of events and processes. The proposed approach greatly enhances support for complex spatio-temporal queries on the behavior and relationships of events and processes.     

基于粒计算的制图综合知识获取模型研究

提出了一个基于粒计算的制图综合选取知识获取模型,旨在探讨从范例数据中获取制图对象之间内在关联知识的途径,为制图综合选取推理提供决策规则。并以河流选取为例,对基于粒计算的制图综合选取的知识获取模型和方法进行了讨论。     

Semi-automatic Process for Hybrid DTM Generalization based on Structural Elements Multi-analysis

Abstract

The generalization of digital terrain models (DTMs) is a tool of great potential for simultaneous cartographic and photogrammetry generation processes at different scales, the main object of which is to feed different geographic information systems (GIS). These GIS enable multi-scale analysis and visualization through different data bases. This research proposes a semi-automatic DTM generalization process conditioned by a series of predefined parameters resulting in the generation of hybrid DTMs at different scales starting from a single cloud of points obtained through large-scale massive data acquisition processes. The generalization results obtained, applied on different areas of different relief, offer specific application ranks for each parameter with great precision, in contrast with DTMs obtained directly in each scale.     

MacLeod,MI4, and the Directorate of Military Survey 1919–1943

Abstract

The organization lineage of the UK Defence Geographic and Imagery Intelligence Agency can be traced back to the seventeenth century. For much of this time the organization, bearing a succession of different titles, formed only a very small section of the armed forces, and, until the World War of 1914–1918, its main duties were the creation and maintenance of a map collection and the acquisition of geographical data of foreign countries. The survey and mapping innovations made during the war greatly enlarged the remit of what was now termed the Geographical Section General Staff (MI4). This paper outlines the work of MI4 in the inter-war years taking account of the principal personalities involved, and traces the controversial background to the creation in 1943 of the Directorate of Military Survey — the immediate predecessor of the DGIA.     

Map Generalization with a Triangulated Data Structure

Automation of map generalization requires facilities to monitor the spatial relationships and interactions among multiple map objects. An experimental map generalization system has been developed which addresses this issue by representing spatial objects within a simplicial data structure (SDS) based on constrained Delaunay triangulation of the source data. Geometric generalization operators that have been implemented include object exaggeration, collapse, amalgamation, boundary reduction and displacement. The generalization operators exploit a set of primitive SDS functions to determine topological and proximal relationships, measure map objects, apply transformations, and detect and resolve spatial conflicts. Proximal search functions are used for efficient analysis of the structure and dimensions of the intervening spaces between map objects. Because geometric generalization takes place within a fully triangulated representation of the map surface, the presence of overlap conflicts, resulting from individual operators, can be detected due to the introduction of singularities in the triangulation, the structure of which is used to generate displacement vectors to resolve the conflict. Examples of the application of the implemented operators are described and illustrated using large scale topographic map data.     

Complex Coastline Generalization

A combination of procedural algorithms and predicate logic formalisms is proposed to generalize complex coastlines. The advantage of this combined strategy is to cover both the geometric and conceptual aspects of the generalization process. The geometric part is dedicated to simplification and displacement operations for graphical presentation. The conceptual part handles the problem of river selection based on geometrical and semantic criteria. The derivation of a hierarchical model reflecting the hierarchical structure of the bay/river network of the coastline is a requirement for river selection. A case study was carried out, and results show an improvement over more conventional procedural approaches. The idea of building a hierarchical model to prepare the ground for feature selection can be applied to other hierarchically structured objects such as road networks or nested buildings in urban areas.     

Terrain Generalization with Multi-scale Pyramids Constrained by Curvature

This paper presents a method for terrain generalization using Laplacian pyramids. The method pre-processes digital terrain for generating cartographically generalized 3D maps. Map authors can attenuated or amplify selected frequency bands of the terrain with a graphical interface imitating an audio equalizer. Ridge lines and valley lines are localized by curvature indices, and their characteristic shapes are preserved or emphasized using additional sets of equalizer controls. Frequency bands are adjusted separately for the foreground and the background to remove visually disturbing terrain detail in the background. This is relevant for 3D maps in central perspective projection that considerably compresses distant terrain features. The proposed generalization method was implemented in Terrain Equalizer, a free and open-source application providing a graphical interface with interactive 3D previews (available at http://www.terraincartography.com/). Using this application, disturbing high frequency details can be easily removed and major mountain forms can be accentuated. The level of generalization can be adjusted seamlessly from the foreground to the background of the 3D map. Topographic break lines, such as ridge or valley lines, are successfully preserved, which is important for conveying the characteristic shape of a generalized terrain.     

Adapting Generalization Tools to Physiographic Diversity for the United States National Hydrography Dataset

This paper reports on generalization and data modeling to create reduced scale versions of the National Hydrographic Dataset (NHD) for dissemination through The National Map, the primary data delivery portal for USGS. Our approach distinguishes local differences in physiographic factors, to demonstrate that knowledge about varying terrain (mountainous, hilly or flat) and varying climate (dry or humid) can support decisions about algorithms, parameters, and processing sequences to create generalized, smaller scale data versions which preserve distinct hydrographic patterns in these regions. We work with multiple subbasins of the NHD that provide a range of terrain and climate characteristics. Specifically tailored generalization sequences are used to create simplified versions of the high resolution data, which was compiled for 1:24,000 scale mapping. Results are evaluated cartographically and metrically against a medium resolution benchmark version compiled for 1:100,000, developing coefficients of linear and areal correspondence.     

基于制图综合知识的空间数据检查

基于制图综合知识的空间数据检查是GIS和制图综合中迫切需要研究的问题。首先,分析数据检查的重要性和制图综合知识在数据检查中的作用。其次,对制图综合知识的归纳进行阐述:在分析国内外研究的基础上,定义一套基于模糊型知识和精确型知识为基础的知识分类模式;并据此提出一种制图综合知识的结构化描述方式;然后提出知识属性的概念,阐述知识属性在知识中扮演的重要作用,定义知识属性的详细指标。第三,进行基于制图综合知识的数据检查:在对数据进行重要性排序的基础上,提出基于模糊型知识的人机协同的数据检查方法,和基于精确型知识的自动数据检查方法,并给出详细的数据检查程序流程。最后,给出相应的例子。从数据检查的结果来看,提出的知识归纳方法能够满足当前制图综合的多种需求,基于知识的数据检查方法能够为进一步实施制图综合提供强有力的信息和依据。     

基于数据库的保质设计制图综合知识库研究

建立基于数据库的保质设计制图综合知识库,并对该知识库中的基本表结构、制图综合知识库的建立与维护、推理机制的实现分别进行阐述。其特点在于对质量知识的有效管理,使制图综合知识的作用不仅仅局限于综合开始阶段针对不同目标进行综合处理方法的选择,而是在综合的各个阶段能够进行质量的自动引导与控制,同时在表结构设计中对保质设计中的质量功能配置进行考虑,能够实现自动推理机制,从而在整个制图综合过程中发挥质量控制的作用。     

Use of Cartographic Analysis for Determining the Morphometric Features of Selected Groups of Glacial Configuration Forms

Abstract

Using a hypsometric map, an analysis was performed of selected morphometric features of topographic profiles differing in terms of origin. The research was based on uniform source materials, namely topographic maps of Poland on a scale of 1:10 000. The spatial distribution of morphometric features has been presented using geometrical cartograms. Summary cartograms, based on normalised and summed up values of individual features, were also developed. A comparative analysis of cartograms was performed in order to establish dominant features. It was established that each of the researched genetic topographic profile types has characteristic morphometric features. Getting its meaning may be helpful when determining the origin and age of topographic profiles. It was also demonstrated that when analysing the morphometry of terrain, it is sufficient to consider dominant features only.     

地形图自动综合知识库的建立方法

本文以地形图自动综合为目的,讨论了如何利用数据库技术建立地形图综合知识库,这种方法能提高知识库中规则的匹配速度。     

基于MRF的航空影像理解的知识获取

讨论了基于MRF影像理解的3种知识——同类影像的距离最短、近邻像元个别特征参数的显著性和影像的方向性在航空影像理解中如何获取和应用。通过航空影像试验,表明影像理解的正确率大大提高。