GIS中的模糊形态运算

空间数据的不确定性是当前GIS领域的研究难点之一。为了描述空间数据的模糊性,把模糊集理论引入GIS,以加强GIS对模糊现象建模的能力,因而产生了模糊数据。但现有GIS缺乏对模糊数据分析和处理的能力。该文把模糊集理论引入数学形态学,提出能处理模糊数据的模糊形态运算,并给出模糊形态运算的隶属函数,使传统的数学形态学能够处理模糊数据且容易在计算机上实现。     

Fuzzy information representation and processing in conventional GIS software: database design and application

Currently used methods for representing geographical information are inadequate because they do not tolerate imprecision. This leads to information loss and inaccuracy in analysis. Such expressive inadequacy is largely due to the underlying membership concept of classical set theory. To improve information processing in GIS research and application, an alternative membership concept is required. In this paper, we explore the inadequacy imposed upon geographical information representation by classical set theory and address the problems of information loss. A fuzzy relational data model is defined which is more representative for geographical information. A GIS database for agricultural land resource management is created by using the data model and a new technique for assessing land suitability is developed. The fuzzy representation largely facilitates data analysis in this GIS. The methods are tested with data from North Java, Indonesia using a vector-based GIS software package, Arc Info, and the analysis results are presented.     

A formal framework for the representation of stack-based terrains

This paper presents a formal framework for the representation of three-dimensional geospatial data and the definition of common geographic information system (GIS) spatial operations. We use the compact stack-based representation of terrains (SBRT) in order to model geological volumetric data, both at the surface and subsurface levels, thus preventing the large storage requirements of regular voxel models. The main contribution of this paper is fitting the SBRT into the geo-atom theory in a seamless way, providing it with a sound formal geographic foundation. In addition we have defined a set of common spatial operations on this representation using the tools provided by map algebra. More complex geoprocessing operations or geophysical simulations using the SBRT as representation can be implemented as a composition of these fundamental operations. Finally a data model and an implementation extending the coverage concept provided by the Geography Markup Language standard are suggested. Geoscientists and GIS professionals can take advantage of this model to exchange and reuse geoinformation within a well-specified framework.     

Spatial video and GIS

GIS elemental unit representations of spatial data are often defined in terms of points, lines and areas. However, another type of spatial data that is becoming frequently captured, but as yet is largely ignored in GIS, is that of video. While digital video recording is a commonly encountered medium in modern society and encompasses many forms, from simple personal camcorders through to sophisticated survey and surveillance systems, its geographical representation in a GIS has not been fully examined or realised. In the majority of cases the video footage is usually captured while the device and/or the objects being viewed are in motion. What is of particular interest is when video streams can be, or have been, associated with spatial data such as location and orientation to create geographically referenced videographic data, which, for simplicity, will be defined as spatial video. Fundamentally, the nature of video is to record space, so when spatial properties can be accurately acquired and associated with this footage, an important geographical element can be considered for integration and analysis within a GIS.

Existing spatial video systems, both commercial and research, are predominantly used in survey or LBS roles and are usually bespoke and application specific. These systems do not model spatial video to any recognised standards that is generalised to be both data and platform independent. They do not support GIS integration and/or analysis from a purely spatial content perspective. A video-image/remote-sensing centric approach prevails where usage options range from simple visualisation interfaces to interactive computer vision systems. What has been largely overlooked is a spatial approach where the inherent geographical extent recorded in each video frame can be modelled and used in a geo-spatial analysis context. While this modelling approach has not been fully realised, it does exist in a GIS form based on Open Geospatial Consortium standards, where the spatial context of video is defined in a structure called a ViewCone. However, a ViewCone only defines a 2D model of the geographical extent of each frame and is restricted to a three-or-five sided polygon representation.

Thus, this article examines the potential of modelling spatial video through the use of elemental data types within GIS; gives some examples of using this approach; describes some problems in using spatial video within GIS; and then demonstrates how these problems are being solved. This is done in three stages: Firstly, a detailed overview of spatial video in its current GIS role is provided – this is achieved through a complete introduction to the distinct elements of spatial video followed by a review of its use in both commercial and academic application areas. Secondly, a brief theoretical overview of an alternative GIS-constrained ViewCone data structure is given that defines a more flexible spatial video model for both 2D and 3D GIS analysis and visualisation. Thirdly, a selective sample of results is presented based on an implementation of this approach being applied to a constrained spatial video data source in a specific study area.     

Relational spatial topologies for historical geographical information

Abstract

Research on time and data models for Geographical Information Systems (GIS) has focused mainly in the representation of temporal geographical entities and implementation of temporal databases. Many temporal GIS database structures have been proposed but most of them just provide principles, not the recipe for the design. Owing to the manipulation of the large quantity of geographical information and the slow response time, few implementations exist. This paper presents a relational method of storing and retrieving spatial and temporal topologies. Two-level state topologies are proposed: a state topology for a set of geographical entities and a state topology for a single geographical entity.

From a temporal perspective, these two-level state topologies may also be viewed as two-level time topologies: a time topology for all geographical entities in a GIS database and a time topology for a single geographical entity. Based on these state and time topologies, a detailed storage approach for historical geographical information is provided.     

Topology revisited: representing spatial relations

Topology is a central, defining feature of geographical information systems (GIS). The advantages of topological data structures are that data storage for polygons is reduced because boundaries between adjacent polygons are not stored twice, explicit adjacency relations are maintained, and data entry and map production is improved by providing a rigorous, automated method to handle artifacts of digitizing. However, what explains the resurgence of non-topological data structures and why do contemporary desktop GIS packages support them? The historical development of geographical data structures is examined to provide a context for identifying the advantages and disadvantages of topological and non-topological data structures. Although explicit storage of adjacent features increases performance of adjacency analyses, it is not required to conduct these operations. Non-topological data structures can represent features that conform to planar graph theory (i.e. non-overlapping, space-filling polygons). A data structure that can represent proximal and directional spatial relations, in addition to topological relationships is described. This extension allows a broader set of functional relationships and connections between geographical features to be explicitly represented.     

Database design for a multi-scale spatial information system

Abstract

Growth in the available quantities of digital geographical data has led to major problems in maintaining and integrating data from multiple sources, required by users at differing levels of generalization. Existing GIS and associated database management systems provide few facilities specifically intended for handling spatial data at multiple scales and require time consuming manual intervention to control update and retain consistency between representations. In this paper the GEODYSSEY conceptual design for a multi-scale, multiple representation spatial database is presented and the results of experimental implementation of several aspects of the design are described. Object-oriented, deductive and procedural programming techniques have been applied in several contexts: automated update software, using probabilistic reasoning; deductive query processing using explicit stored semantic and spatial relations combined with geometric data; multiresolution spatial data access methods combining poini, line, area and surface geometry; and triangulation-based generalization software that detects and resolves topological inconsistency.     

基于场所的GIS研究

探讨从地理空间认知出发,实现基于场所的GIS（PB—GIS）的相关问题。PB—GIS以场所为核心,显式表达地理空间知识,并遵循特定规则进行定性空间推理,从而服务于空间行为决策。比较PB—GIS与基于坐标的GIS（CB—GIS）之间的差异和适合解决的问题,并描述定性空间推理的特点及其在PB—GIS中的应用。在分析实现PB—GIS的关键技术基础上,采用三层架构设计了一个PB-GIS的概念体系结构。     

Fuzzy representation of geographical boundaries in GIS

Abstract

Polygon boundaries on thematic maps are conventionally considered to be sharp lines representing abrupt changes of phenomena. However, in reality changes of environmental phenomena may also be partial or gradual. Indiscriminate use of sharp lines to represent different types of change creates a problem of boundary inaccuracy. Specifically, in the context of vector-based GIS, use of sharp lines to represent gradual or partial changes may cause misunderstanding of geographical information and reduce analysis accuracy.

In this paper, the expressive inadequacy of the conventional vector boundary representation is examined. A more informative technique—the fuzzy representation of geographical boundaries—is proposed, in which boundaries describe not only the location but also the rate of change of environmental phenomena. Four methods of determining fuzzy boundary membership grades from different kinds of geographical data are described. An example of applying the fuzzy boundary technique to data analysis is presented and the advantages of the technique are discussed.     

基于场所的GIS中的不确定性问题及分类框架

基于场所的GIS直接表达人类地理空间知识的管理和加工过程,而不确定性是人类智能的基本特点,因此GIS的智能化需要研究其中的不确定性问题。与传统的GIS相比,基于场所的GIS中的不确定性问题更为丰富,既包括随机性,也包括含糊性,而不确定性的主体既可以是地理要素、场所和空间关系,也包括命题和规则。该文介绍该领域相关的研究成果,基于不确定性主体、类型、表达手段及相关的活动4个视角,建立了基于场所的GIS中所涉及的不确定性框架,从而为相关的不确定性建模提供指导。     

“面向区域”的GIS控件的设计与使用

本文提出了一个“面向区域”GIS控件的概念———即以特定的地理区域为对象,将基础地理信息连同有关的GIS功能操作融合为一个可重用的程序模块,以Microsoft的COM(即“组件对象模型”)技术为基础,组织为“GIS化”的ActiveX控件。这种GIS控件,将面向对象技术中的“对象”扩展到了整个特定的地理区域空间,其核心思想是不仅封装了GIS的数据模型,必要的功能操作,而且封装了所有的基础地理信息。由于省去了对空间数据的处理,因而这种GIS控件可被广大非GIS专业的信息系统开发者灵活、简便地用于各种管理信息系统、办公自动化系统和决策支持系统的GIS功能扩充,也可用于构建一般的地理信息系统,因而有利于GIS技术应用的普及。文章最后给出了有关陕西省的应用实例     

GIS作为新一代地理学语言的特征(英文)

Language plays a vital role in the communication, sharing and transmission of information among human beings. Geographical languages are essential for understanding, investigating, representing and propagating geo-spatial information. Geographical languages have developed and evolved gradually with improvements in science, technology and cognitive levels. Concerning the theoretical progress from geographical information ontology, epistemology and linguistic theory, this paper firstly puts forward the concept of a GIS language and discusses its basic characteristics according to changes in the structures, functions and characteristics of geographical languages. This GIS language can be regarded as a system of synthetic digital symbols. It is a comprehensive representation of geographical objects, phenomena and their spatial distributions and dynamic processes. This representation helps us generate a universal perception of geographical space using geographical scenarios or symbols with geometry, statuses, processes, spatio-temporal relationships, semantics and attributes. Furthermore, this paper states that the GIS language represents a new generation of geographical language due to its intrinsic characteristics, structures, functions and systematic content. Based on the aforementioned theoretical foundation, this paper illustrates the pivotal status and contributions of the GIS language from the perspective of geographical researchers. The language of GIS is a new geographical language designed for the current era, with features including spatio-temporal multi-dimension representation, interactive visualization, virtual geographical scenarios, multi-sensor perception and expedient broadcasting via the web. The GIS language is the highest-level geographical language developed to date, integrating semantic definitions, feature extraction, geographical dynamic representation and spatio-temporal factors and unifying the computation of geographical phenomena and objects. The GIS language possesses five important characteristics: abstraction, systematicness, strictness, precision and hierarchy. In summary, the GIS language provides a new means forpeople to recognize, understand and simulate entire geo-environments. Therefore, exploration of the GIS language’s functions in contemporary geographical developments is becoming increasingly important. Similarly, construction of the conceptual model and scientific systems of the GIS language will promote the development of the disciplines of geography and geographical information sciences. Therefore, this paper investigates the prospects of the GIS language from the perspectives of digital technology, geographical norms, geographical modeling and the disciplinary development of geography.     

A new geographical language：A perspective of GIS

Language plays a vital role in the communication, sharing and transmission of information among human beings. Geographical languages are essential for understanding, investigating, representing and propagating geo-spatial information. Geographical languages have developed and evolved gradually with improvements in science, technology and cognitive levels. Concerning the theoretical progress from geographical information ontology, epistemology and linguistic theory, this paper firstly puts forward the concept of a GIS language and discusses its basic characteristics according to changes in the structures, functions and characteristics of geographical languages. This GIS language can be regarded as a system of synthetic digital symbols. It is a comprehensive representation of geographical objects, phenomena and their spatial distributions and dynamic processes. This representation helps us generate a universal perception of geographical space using geographical scenarios or symbols with geometry, statuses, processes, spatio-temporal relationships, semantics and attributes. Furthermore, this paper states that the GIS language represents a new generation of geographical language due to its intrinsic characteristics, structures, functions and systematic content. Based on the aforementioned theoretical foundation, this paper illustrates the pivotal status and contributions of the GIS language from the perspective of geographical researchers. The language of GIS is a new geographical language designed for the current era, with features including spatio-temporal multi-dimension representation, interactive visualization, virtual geographical scenarios, multi-sensor perception and expedient broadcasting via the web. The GIS language is the highest-level geographical language developed to date, integrating semantic definitions, feature extraction, geographical dynamic representation and spatio-temporal factors and unifying the computation of geographical phenomena and objects. The GIS language possesses five important characteristics: abstraction, systematicness, strictness, precision and hierarchy. In summary, the GIS language provides a new means for people to recognize, understand and simulate entire geo-environments. Therefore, exploration of the GIS language’s functions in contemporary geographical developments is becoming increasingly important. Similarly, construction of the conceptual model and scientific systems of the GIS language will promote the development of the disciplines of geography and geographical information sciences. Therefore, this paper investigates the prospects of the GIS language from the perspectives of digital technology, geographical norms, geographical modeling and the disciplinary development of geography.     

过程地理信息系统框架基础与原型构建

GIS的发展正在从基于空间状态的“静态”基础走向基于时空过程的”动态”基础。作者提出了过程地理信息系统(PGIS)的概念及其理论框架体系。本文剖析了PGIS中过程所在的时空范畴,阐述了过程在PGIS中的含义及其结构,并探讨了PGIS基本空间框架、体系结构和过程仓库的理论基础。在此基础上,定义了PGIS的基本时空处理分析功能范畴,从过程的时空特性出发,结合所研发的海洋地理信息系统平台MaXplorer,阐述了PGIS不同于传统GIS的相关功能,即过程管理、可视化、特征化、对象化、逻辑运算和符号化等。     

A transformational approach to GIS operations

GIS research has a continuing thread devoted to classifying the operations performed by analytical software. Prior efforts to classify GIS operations have limitations and inconsistencies, often arising from an attempt to establish overly direct links between geographic procedures and arithmetical operations. The transformational view of cartography provides a more solid basis for classifying GIS operations. This paper presents a new scheme for geographical transformations based on measurement frameworks as the principal distinction. Transformations between measurement frameworks can be summarized in terms of a spatial neighbourhood and a rule to process attribute information. This scheme organizes most analytical GIS operations by their geometric and attribute assumptions.     

GIS作为新一代地理学语言的特征

地理学语言是人类理解、研究、表达与传播地理信息的重要工具, 它随着人类科学技术的进步与认识水平的提高而不断演进。本文根据地理学语言在结构、功能及其特征方面所发生的变化, 结合地理信息本体论、认知论和语言学理论, 总结了GIS 语言的定义与基本属性, 阐述了GIS作为新一代地理学语言的本质特征、结构、功能以及内容体系, 明确了其在地理学研究中的地位与作用。GIS语言实现了地理对象的语义定义、特征抽象、行为表达和时空运算处理过程的高度统一, 是地理学语言的高级形态;通过分析GIS 语言所具有的抽象性、系统性、严密性、确切性、层次性等基本特征。认为GIS语言的概念与体系结构的形成, 将推动地理学及地理信息科学的发展。文中从数字技术的影响、学科范式的转变、发展导向和地理表达能力四个方面对GIS语言的研究作了展望。     

地理空间意像模式的Voronoi模型

提出用Voronoi空间模型来表达意像模式，Voronoi模型无岐义空间邻近关系，构建能封装对象间空间关系的拓扑网络，使用该模型将各种空间介词映射为不同的拓扑结构，GIS采用该模型，可按自然语言中空间介词描述的定性空间关系查询检索模糊地理信息。     

A spatial analytical perspective on geographical information systems

Abstract

The field of geographical information systems (GIS) is reviewed from the viewpoint of spatial analysis which is the key component of the familiar four-part model of input, storage, analysis and output Input is constrained by the limits of manual methods and problems of ambiguity in scanning. The potential for developments in output is seen to be limited to the query mode of GIS operation, and to depend on abandoning the cartographic model. Discussion of storage methods is organized around the raster versus vector debate and the need to represent two spatial dimensions in one. A taxonomy of GIS spatial analysis operations is presented together with a generic data model. Prospects for implementation are discussed and seen to depend on appropriate scales of organization in national and international academic research.