A design of three-dimensional spatial data model and its data structure in geological exploration engineering

The key to develop 3-D GISs is the study on 3-D data model and data structure. Some of the data models and data structures have been presented by scholars. Because of the complexity of 3-D spatial phenomenon, there are no perfect data structures that can describe all spatial entities. Every data structure has its own advantages and disadvantages. It is difficult to design a single data structure to meet different needs. The important subject in the3-D data models is developing a data model that has integrated vector and raster data structures. A special 3-D spatial data model based on distributing features of spatial entities should be designed. We took the geological exploration engineering as the research background and designed an integrated data model whose data structures integrats vector and raster data byadopting object-oriented technique. Research achievements are presented in this paper.     

An integrated data model in three dimensional GIS

The current GIS can only deal with 2-D or 2.5-D information on the earth surface. A new 3-D data structure and data model need to be designed for the 3-D GIS. This paper analyzes diverse 3-D spatial phenomena from mine to geology and their complicated relations, and proposes several new kinds of spatial objects including cross-section, column body and digital surface model to represent some special spatial phenomena like tunnels and irregular surfaces of an ore body. An integrated data structure including vector, raster and object-oriented data models is used to represent various 3-D spatial objects and their relations. The integrated data structure and object-oriented data model can be used as bases to design and realize a 3-D geographic information system.     

地勘工程3维空间数据模型及其数据结构设计

3维现象随着研究领域的不同，描述空间实体的方法存在较大差异，不可能设计一种数据模型来适合所有的应用领域，应根据研究领域空间实体分布特征，设计出专用的3维空间数据模型。本文对传统的3维数据模型进行了分析，以地质勘探工程的各种3维空间对象为研究背景，提出了适合地质勘探工程的矢量与栅格集成的面向对象混合数据模型，以复杂体－体－面－线－点对象之间的逻辑关系来建立对象之间的拓扑关系，设计了部分对象的数据结构，并以一玢岩型铁矿床为例，对数据结构进行了描述。     

A new trapezoidal-mesh based data model for spatial operations

This paper presents a new spatial data model based on trapezoidal-mesh for implementing spatial operations within geographical information systems (GIS). Based only on the solid foundation of spatial operations, diversified application models can be established to bridge the gap between Digital Earth models and the real world with its real-world problems (‘connecting through location’). In this paper, the involved polygon features are decomposed into a series of trapezoidal-meshes. Then, geo-processing operations are employed on these meshes rather than the original polygon features, resulting in a relatively simple spatial computation. As a kind of model designed by integrating raster with vector, the model presented here has advantages over other models when carrying out spatial operations insofar as providing a solid foundation for achieving the grand goal of Digital Earth. The concept of this data model and the two extensive examples of its application in spatial operations are elaborated upon in this article. As a result, this article and the research that supports it, proves that the adoption of the trapezoidal-mesh model greatly improves the efficiency of spatial operations in GIS.     

面向目标的栅格矢量一体化三维数据模型

首先对现有的三维空间数据模型进行了讨论 ,分析了栅格、矢量和混合数据模型的特点 ,提出了一种面向目标的栅格矢量一体化数据模型。该模型将栅格数据以矢量方式进行组织 ,从而同时具有矢量和栅格数据模型的优点 ,也克服了目前普遍应用的混合模型所存在的缺点。还提出了一种三维空间的三级栅格划分和行次序编码方法。该方法存储空间小 ,便于快速索引和计算。最后 ,给出了具体的数据结构     

Algorithms for Tetrahedral Network(ten) generation

The Tetrahedral Network(TEN) is a powerful 3-D vector structure in GIS, which has a lot of advantages such as simple structure, fast topological relation processing and rapid visualization. The difficulty of TEN application is automatic creating data structure. Although a raster algorithm has been introduced by some authors, the problems in accuracy, memory requirement, speed and integrity are still existent. In this paper, the raster algorithm is completed and a vector algorithm is presented after a 3-D data model and structure of TEN have been introducted. Finally, experiment, conclusion and future work are discussed.     

Algorithms for Tetrahedral Network(ten) generation

1 IntroductionA fulI 3-D GIS is needed in rnany gerecience ap-plication fields, such as goology, mine, oil and en-virorunental engineering, etc. Not only medelingand visualization but also rnanipulation are requiredin these applications. But the traditional 2-D GIShas difficulty in satisfying these fequirements, es-pecially in the representation of vertical infOrma-tion. Although a number Of studies have been dOneby researchers in the world (Molenaar, 1992; RaPerand Kelk, 199l; Li Rong…     

栅格数据坐标变换模型在数据集成中的应用

在数据转换过程中如何尽可能地保证空间数据的完整性和准确性成为限制GIS发展的瓶颈问题。本文针对GIS矢量数据在数据转换过程中选点难,转换之后出现几何位置差异的问题,提出基于栅格数据坐标变换模型,采用图像数据转换时的控制点,将矢量数据纠正到标准的目标构件图库中,达到矢量空间数据有效匹配的效果。进行矢量数据变换时,针对仿射变换、多项式模型等变换模型的限制性,基于Delaunay三角网对平面进行剖分,将纠正误差进行局部控制。最后,以ShapeFile为例实现了几何纠正算法。     

梯形面片数据模型及其空间运算应用

提出一种新的基于梯形面片的空间运算方法,该方法将多边形要素预先分解成一系列的梯形面片,后续的空间运算将不再基于原始多边形要素进行操作,而是对分解产生的梯形面片进行更为简便的计算处理。梯形面片模型结合了常见矢量数据模型数据精度高、栅格数据模型运算简单等优点,在执行相关空间运算中与常见矢量和栅格模型相比具有优势。详述了该数据模型,并以点面包含分析和多边形叠置分析等实例探讨了其在空间运算中的应用,测试与分析表明该方法兼具数据精度高、算法实现简单等优点,能较有效地提高空间运算的执行效率。     

不同空间数据格式的数据量实验研究

针对一些通用的空间数据的数据交换格式进行了研究，并就不同数据格式的数据量进行了对比实验。结果表明，在栅格数据中，．bmp格式的数据量最大，.jpg格式和．gif格式的数据量较小；矢量格式的数据量的大小与空间数据的属性有关，在几种常用的矢量格式中，．e00格式的数据量最大。     

矢量与栅格集成的三维数据模型

以矿山地质为背景，深入分析三维空间信息系统所涉及到的空间对象以及它们之间的联系，提出了几种新的空间对象类型。探讨用矢量与栅格混合的数据结构，以及面向对象的数据模型来表达各类三维空间对象，以此作为设计和建立三维地理信息系统的基础     

工程地质三维空间建模技术及其应用研究

对工程地质研究的主要三维空间对象(勘探区域三维地质剖面体)进行了规范化的构造描述，对当前主流三维空间建模方法进行了综合分析。在此基础上，结合专业建模对象的构造特点及三维数据模型适用表达对象的不同特性，融合单元分解表示(CE)、构造实体几何(CSG)和边界表示(B-Reps)三种数据模型的建模思想，以及栅格模型的基本体元划分机制和数据组织方式，以不规则五面体为基本分析单元，采用面向对象方法构造模型内各娄对象，提出了一种面向对象的三维矢量与栅格混合模型，实现了勘探区域三维地质剖面体的惟一性拓扑表达，并给出了可视化方案。分析了几例基于此模型的工程地质应用，借以验证该模型在工程地质领域内应用的合理性和可操作性。     

多尺度空间数据索引方法研究

以多尺度空间数据为研究对象,讨论其混合索引结构的建立方法。对于多尺度矢量空间数据提出基于多层次网格与R 树混合索引结构,栅格数据进行分块并建立四叉树索引结构。利用双向链表结构连接同尺度下的矢栅空间数据,实现矢栅之间的无缝转化;并用地理数据编码及双向链表结构连接不同尺度下的同一空间对象,实现多尺度空间对象的纵向无缝连接。进而实现多尺度空间数据的快速可视化及空间对象的纵向无缝查询。     

3D GIS技术研究发展综述

回顾了3DGIS的发展进程,从三维空间数据获取,三维数据模型,三维空间数据管理和分析以及三维可视化技术4个方面综述了3DGIS技术的发展。探讨了目前研究3DGIS的4个热点问题:①数据源集成快速获取数据的方法;②不同数据模型的集成;③支持空间分析的面向对象的数据模型;④城市三维模型。     

矢栅一体化拓扑关系的度量描述研究

首先,借助传统的9交模型确定了矢栅一体化数据模型拓扑关系的定性表达;其次,利用重叠部分的栅格数目占各个目标的比率来确定交叠分量,同时根据栅格的统计量来描述两目标接近程度的邻近分量;最终,将定性的拓扑关系、用以度量化描述的交叠分量及邻近分量以三元组的形式来描述目标间的拓扑关系,从而更加有效地实现了多类型地理目标拓扑关系的度量化描述。     

地学栅格格网数据质量评价指标与方法

栅格格网数据在GIS空间分析中具有巨大优势,但是其质量优劣很大程度上影响着这些基础数据的应用能力。本文结合地球系统科学数据共享网(科学数据共享工程试点)中栅格格网数据现状,提出该数据质量评价的指标和方法。具体指标包括图形、属性、时间和元数据四个大的要素集,通过与精度、逻辑一致性与完整性的匹配,组成一个的评价指标矩阵。基于缺陷扣分法和加权平均法设计了数据质量评价技术路线,并以地球系统科学数据共享试点中的栅格格网数据为实例,验证了本技术方法。     

三维空间数据模型集成的概念框架研究

本文对三维空间数据模型的研究与发展进行了总结,分析了三维空间数据的特点以及数据模型集成的必要性。结合三维ＧＩＳ在城市、地质、海洋等领域的具体应用,提出三种三维空间数据模型集成：用于城市三维构模基于ＴＩＮ和ＣＳＧ的集成模型;用于地质,海洋等领域的基于八叉树和四面体格网的混合模型;具有一般性的矢量栅格集成的三维空间数据模型。     

The CNSDTF topological vector model and structure

Geo-Spatial Data Transfer Standard is an important part of “National Spatial Data Infrastructure (NSDI)”, as well as a necessary means for data sharing. “Chinese National Geo-Spatial Data Transfer Format (CNSDTF)” was approved by National Quality Technology Supervise Bureau in 1999 with the standard serial number of 17798-1999. It is designed to support vector and raster spatial data. This paper describes the vector part of CNSDTF, including design ideas, main characters, conceptual model, definition of spatial object, and file structure.     

The CNSDTF topological vector model and structure

Geo-Spatial Data Transfer Standard is an important part of "National Spatial Data Infrastructure(NSDI)" ,as well as a necessary means for data sharing. "Chinese National Geo-Spatial Data Transfer Format (CNSDTF)" was approved by National Quality Technology Supervise Bureau in 1999 with the standard serial number of 17798-1999. It is designed to support vector and raster spatial data. This paper describes the vector part of CNSDTF, including design ideas, main characters, conceptual model, definition of spatial object, and file structure.