【作者】 应申；

【导师】 李霖；

【作者基本信息】 武汉大学 ， 地图制图学与地理信息工程， 2005， 博士

【摘要】 地理信息系统的重要应用之一在于其空间分析能力,在国内外一直都备受关注,但却始终处于薄弱环节。GIS研究的是地理对象,它依赖于地理空间的地域性。而这种地域性受人类的感觉或视觉范围所限制,尽管现代技术一定程度上能帮助我们。人们通过视觉可视来对地理环境进行观测、认识和建模。观察和认识地理环境是空间可视分析的最本质的内容,在手段上其强调人们对地理空间可视的广度和粒度,这是认识和分析地理空间的基础。 人类对世界的认识主要依靠视觉,因此地理认知和分析主要处于这种可视空间下。基于地理空间的思考,论文探讨了视觉和心理空间,提出可视问题的概念和分类,该概念致力于解释可视问题的本质和内在联系。 空间可视分析和认知是分不开的,作为自然界主体的人是空间可视分析的基础,论文首先探讨人的视觉生理机能,进而分析视觉可视分析中的感知和认知,这是我们认识地理空间的根源。特别是空间视感中视域和分辨率,尽管在计算时处理的方法不同,但它们是研究空间可视分析计算的基础。视觉可视分析和空间感知与认知是密不可分的,一定外延上空间可视分析涵盖了视觉地理空间分析的全部内容,或者说两者是等价的。这是论文第二章研究的重要内容。 空间可视分析在可定量分析上表现为空间广度和空间粒度,而这是属于空间尺度的范畴。论文以空间尺度作为可视分析的理论基础,详细探讨了地理信息科学领域中的空间尺度问题。空间尺度问题出现在各种空间分析中,被认为是空间信息学科中一个最模糊和基本的方面。尺度是我们观察世界和研究世界的纽带,其核心问题是尺度依赖和尺度相关的自然性问题。任何依赖尺度的分析和推理都受被研究对象的广度和粒度约束。在可视分析中,尺度有两个类似意义。论文将尺度集成到空间可视分析中。其中涉及到空间视觉认知、方法论、过程或现象的概念框架等。本研究的目的是对空间尺度进行特征化、概念化,理解空间尺度在空间可视分析和制图表达中的效用,试图揭示空间尺度和制图综合的本质联系。论文探讨了空间尺度内在蕴涵的定义,包括认知尺度、空间广度、空间粒度、比例尺等,它们之间是互为影响和约束的,同时论文也探讨了对空间尺度在不同的分析层次上所研究的内容和关系。 空间可视分析的技术主要体现在可视性和视域的计算上。平面上表现为多边形环境中的视域计算,因其在应用中多描述为监视问题,因此也称之为平面监视问题。根据视点的位置、路径、运动和多边形环境的不同,平面监视问题表现为多种形式:多边形顶点监视、内部点监视、动态和路径监视、多点优化监视等。论文以典型的艺术馆问题为例论述了顶点监视的描述、求解方法。其核心是多边形分割和着色问题,难点或特殊点在于它是求解最差最优解。论文重点探讨了顶点监视、内部监视问题,探讨了基于视线运动的多边形分割情况,提出了沟的关键事件方法,并给出了具体的解决方法,能有效地探索多边形环境中的视域,其广泛地应用于各种监控领域和应用设计领域,如楼宇监视、路径规划等。同时简要论述了动态和路径监视,其求解的本质是一致的。 地形作为GIS空间分析的主要研究对象,同时也是空间可视分析的对象。三维地形可视分析由于其影响因素众多和地形特征的复杂性,在具体可视计算时,方法和手段也不尽相同。论文在第四章首先分析地形可视分析的影响因素,有客观自然的,也有主观人为的,主要有:地形特点、基础高程数据情况、视点的选择、高程值的获取方法、视点与目标点以及LOS的特点、数值计算特征、可视参数控制等等。这些影响因素是具体分析和应用时必须考虑的,要结合情况进行具体的处理。地形可视计算包括可视性LOS计算和可视域计算,通常可视性计算是视域计算的基础,但新的方法可以直接进行视域的计算(如多个体模拟)。论文具体探讨了可视性计算和视域计算的原理和方法。寻找合适的方法来进行可视分析的计算,减少计更多还原

【Abstract】 The ability of spatial analysis is one of the most important implementations of GIS, which is widely regarded by many scholars in the world. However, it is still a weak part in most GIS systems. The objects of GIS, geographic objects, depend on geospatial regional differences. The regional differences are limited by human being’s perception and visual scope even though the modern technologies can help us to some extent. We always observe, cognize and modeling geographic environment through our visibility. The observation and cognition of geographic environments are the primary contents in spatial visibility analysis, which emphasize on the geospatial visibility extend and resolution in methods. This is fundamental for perceiving and analyzing geo-space. Based on the research of geo-space, this paper discusses visual and psychological space, and advances the concepts and classification of visibility. The concepts are used to interpret the essence and internal relations of visibility.As a principal part for natural space, human are the fundamental parts in spatial visibility analysis. The paper first discusses the human visual physical enginery, and furthermore analyzes conception and cognition in visibility analysis, as they are the root of the way that we conceive the geo-space. Though they are different in the process approaches, the viewshed and resolution in spatial vision are especially fundamental in the study of spatial visibility. In certain extension we can say spatial visibility analysis includes all the contents of visual geospatial analysis. And we will discuss the above contents in chapter 2.Spatial visibility analysis is expressed as spatial extension and spatial resolution in the quantitative analysis, which is in the scope of spatial scale. The paper discusses in detail about spatial scale in the field of geographical information science. The problem of spatial scale is the confusion but fundamental aspect in GIScience. The issue of spatial scale is present in all forms of spatial analysis and has been identified as one of the most ubiquitous and fundamental aspects of spatial research. Scale provides the required link between what is studied and the observation. The core of the problem is the nature of scale dependency and scale-linkage. Any research dependent on scale is constrained by the spatial extension and resolution of the observed objects. The objective of the study is to conceptualize, characterize and interpret scale effects in spatial visibility and cartographic representation, to reveal the essence of linkage between of spatial of scale and cartographic generalization. The definitions and meanings involved in the scale discussed in this paper are delivered, such as cognitive scale, spatial extend, spatial resolution and map scale. Then it discussed the content and relationships of scale from different analytical levels.The main calculations of spatial visibility analysis are visibility and viewshed. On a plane they refer to viewshed analysis in the polygon environment and as it is described as surveillance problem in practice. Due to different position, route, movement and polygon environment of viewpoints, plane surveillance can be expressed in many formats. The paper discusses the description and solution methods of the vertex supervisor in typical art gallery problems (AGP) for example. The core problems of AGP are polygon segmentation and vertex coloring, difficulty and particularity lie on its solution for optimize the worst. The paper concentrates on the problems about vertex supervisor and internal supervisor, and discusses polygon segmentation problem based on the sight movement, presents key events method about channel and even its concrete solution, which can effectively explore the viewshed in the polygon environment. And finally we simplydiscuss dynamic and route planning.Terrain is another important study object of GIS spatial visibility. The calculation methods and approaches of 3D relief visibility analysis are different because the differences in the factors and complexities about the terrain characteristics. The chapter 4 will firstly analyze the objective and subjective factors of terrain visibility analysis such as relief characteristics, fundamental elevation data, the choice of viewpoint and capture methods of elevation values, the characteristics of LOS, the characteristics of numerical value, visual parameters control and so on. Those factors will be deal in the practice combined with different circumstances. Terrain visibility calculation consists of LOS calculation and viewshed calculation. Generally speaking visibility calculation is the foundation of viewshed calculation and still there are many new approaches to calculate viewshed directly such ad multi-agent simulation. The paper discusses the principle of visibility and viewshed calculation. The paper delivers an incremental method to calculate terrain visibility with comparison of elevation difference using increments base on grid size. The method is more simple, lower complexity and easier to realize.Visibility analysis depends mostly on the methods that we process data, so the result will be a little different. In this paper the fuzzy and accuracy of the result will be discussed. LOS visibility and viewshed is the basic visual expression of relief, and we provide different analytical results through different visibility analysis to satisfy different demands and take their implementations in martial affairs as examples. In chapter 4 we also discussed the relationship between terrain visibility analysis and perception and behavior decisions. And after analyzing the relationship between visibility and terrain characteristics, we found they are non-high correlation.Spatial visibility analysis is tightly relative to human vision, and the techniques of visibility analysis are used to plan, analyze and evaluate the visual landscape, such as urban landscape, road landscape, scene landscape and archeology landscape. The paper takes Mt. Mo resort as an example in fifth chapter, calculates the viewshed of viewpoints in Mt. Mo to estimate the scope, characteristics of viewshed to see whether it can browse other viewpoints and scenes. The paper uses the integration of GIS data to estimate the connectivity of viewpoints. In order to stand out the effects of viewpoints and give us the personally perceptions on the scene, we construct the virtual Mr. Mo landscape system, through which we can browse the beautiful scenes. Landscape system is an efficient tool to predict and estimate urban landscape system, and the paper uses the spatial visibility analysis to protect mountain landscape during urban construct and discusses the estimate methods of urban landscape based on visibility analysis.When the results of spatial visibility analysis feed back to human, they will affect our behaviors and decisions, which is related with human cognition. In urban space, we move in streets and the results of visibility can be presented in two ways: how much we can see and how long we can see. And naturally we may have certain trend to move or take direction. Spatial visibility analysis is a novel method in urban morphology and spatial configuration, which is an important tool in space syntax. The paper first discusses the concepts of visibility centricity, and quantifies the parameters of visibility analysis on viewpoints to explore urban morphology of street network with pedestrian movement. The paper takes wuhan zhongnan district as an example. This method of pedestrian flow with visibility can be expended to other urban group, such as car flow, bike flow. Urban morphology determines the urban flow, and urban group affect inversely the configuration and layout of urban infrastructures, such as garden, plaza.Since spatial scale is foundation of spatial visibility analysis, which mainly embodies in spatialextend and resolution, what is the coherent constraints and what is the intrinsic relationships between them, how do they response to geographic space? We discuss these content about visibility analysis and multi-scale in seventh chapter. The paper first make known that spatial resolution of visibility is the criterion when we percept and cognize our geographic environment. We have different cognition level with different resolution, then gain different spatial pattern, which is the essence of scale in map generalization geographic landscape. The paper discusses constrains between extend and resolution is the potential standard of analysis and process of geodata, which is completely accord with human vision system.更多还原