基于SVG的空间数据多尺度表达

基于空间数据格式的多异性和兼容性较差的特点,以及地理空间数据互操作的要求,分析了空间数据的多尺度的特征,提出基于可缩放矢量图(SVG)文件格式组织空间数据,对不同分辨率的空间数据采取分级表达,并描述不同尺度空间数据的关联关系。     

基于不完全四叉树的数字水深模型多尺度表达

空间数据的多尺度表达问题是GIS领域研究的重点和难点问题之一。以数字水深模型(DDM)为研究对象,从DDM的几何形态角度出发,通过挖掘水深点之间的空间几何关系,构建了基于不完全四叉树的DDM多尺度表达模型。实验证明,该模型在符合DDM多尺度表达基本原则的前提下,能较好地保持DDM的基本地形特征,同时具有较高的计算效率。     

基于OGSA-DAI的地理空间数据服务的发布

分布式多源异构地理空间数据的访问与集成一直是 GIS(地理信息系统)领域研究的重点。 OGSA-DAI 是专门用于网络(网格)环境下数据访问与集成的网格中间件,在国内外得到了广泛的应用。 对 OGSA-DAI 软件作了详细的介绍,并研究了 OGSA-DAI 的扩展技术,使之支持地理空间数据。 最后阐述了以 OGSA-DAI 为基础的地理空间数据服务发布的方法。     

基于聚类过程的多比例尺GIS空间数据模型设计

在面向对象的数据模型的构造基础上,提出一种基于聚类过程的多比例尺空间数据模型,并得到尺度依赖的空间数据表达。以图斑数据为实例,通过空间分布与距离信息的聚类过程,建立了图斑数据的多比例尺分层分区的数据模型,从而由数据本身实现多尺度表达与综合的模型化,降低或消除了制图综合过程中的主观影响和不稳定性,改进和提高了多尺度表达与综合的效果和质量。     

基于Lustre文件系统的分布式地理数据存储系统的研究

随着测绘领域获取地理数据的手段不断进步,以及目前对存储模式的安全性和稳定性的要求越来越高, 传统的数据存储模式已经不能够满足用户的需求。 针对这一问题,通过对 Lustre 文件系统的结构和优越性进行的分析和总结,提出了应用基于 Lustre 的多文件系统用来存储地理数据,并给出了具体的地理空间数据的存储和管理的组织方法。 最后通过实验验证了这种组织方法的有效性。     

多尺度耦合经验正交分解法反演海洋次表层温盐结构

针对提升利用卫星观测海面信息重构三维温盐场精度的问题, 本文提出了一种基于多尺度耦合正交分解的三维温盐场重构方法。该方法利用多尺度耦合正交分解对历史温盐剖面进行从大尺度到小尺度的迭代分解, 以分层提取不同尺度三维温盐场的特征信息, 然后分别建立海洋表面卫星观测与不同尺度的三维温盐场特征信息的重构模型, 从而达到三维温盐场重构的目的。本文分别利用多尺度耦合正交分解法与单层正交分解法进行三维温盐场重构, 结果显示, 多尺度耦合正交分解优于单层正交分解法, 且随着分解的层次不断细化, 重构温盐场的精度及其垂直梯度精度均呈现明显的提升, 其中组合4精度提升程度最高, 分别提升了25.57%和27.58%; 同时, 对比HYCOM模式数据, 多尺度耦合正交分解重构方法能有效地捕捉次表层海洋的空间特征信息。总体上, 本文耦合经验正交分解法反演的温盐场与Argo温盐场偏差较小, 反演精度较好, 在空间分布上趋于一致。     

基于ECDIS的多数据源支持技术分析

利用多源地理空间数据集成和融合理论,研究了基于ECDIS的多数据源支持技术。介绍了常用的多源海图数据及其使用原则,分析了ECDIS多数据源支持技术的特点及内涵,总结了国内外常用多源海图数据集成方法,从数据可用性角度探讨了提高国产电子海图系统适用性的措施。     

地理信息系统中的数字化质量控制

地理信息系统(GIS)中涉及的数据是具有丰富地理特征的地理数据集合。这些数据信息量大、来源复杂,只有建立完善的质量控制体系,才能使数据的采集和存贮规范化,从而建立起高质量的GIS地理数据库。数字化作为地理信息系统有关图形图件数据采集的重要方式,是获取空间数据的重要手段,尤其要对其进行严格的质量控制。     

面向过程的海洋时空数据分布式存储与并行检索

海洋现象特征数据是一类带有过程性质的时空数据,具有多样性、多态性、海量性和时变性等特点,广泛服务于海洋灾害预报、船舶航行规划、台风路径追踪、海洋与大气环流等领域。本文根据海洋现象特征,建立海洋现象过程的对象表达和数据组织模型,设计三维空间海洋时空数据分片策略和R树空间数据索引方法,以提高海洋现象过程时空数据的查询效率。实验通过构建海洋现象过程时空数据分布式存储与并行检索系统测试算法的执行效率。实验结果表明,面向过程的海洋时空数据分布式并行检索算法能够实现数据的高效检索,验证了海洋现象过程对象数据组织模型的合理性,为研究海洋现象过程多要素的关联机制提供了有效的方法和理论基础。     

基于多尺度小波特征的高光谱影像亚像素目标识别

提出了一种基于多分辨率小波高频特征系数的高光谱遥感影像亚像素目标识别方法。首先利用多尺度小波变换将光谱信号分解为不同尺度的高频特征信号,然后借助接收操作特性曲线(ROC)和马氏距离投影寻踪求取一维最佳识别特征,最后通过高斯最大似然决策函数求解亚像素目标的存在概率。通过38种小波函数的高光谱数据实验证明,该方法对亚像素目标的识别效果较好。     

Mapping Submerged Aquatic Vegetation with GIS in the Caloosahatchee Estuary: Evaluation of Different Interpolation Methods

This article evaluates different spatial interpolation methods for mapping submerged aquatic vegetation (SAV) in the Caloosahatchee Estuary, Florida. Data used for interpolation were collected by the Submersed Aquatic Vegetation Early Warning System (SAVEWS). The system consists of hydro-acoustic equipment, which operates from a slow-moving boat and records bottom depth, seagrass height, and seagrass density. This information is coupled with geographic location coordinates from a Global Positioning System (GPS) and stored together in digital files, representing SAV status at points along transect lines. Adequate spatial interpolation is needed to present the SAV information, including density, height, and water depth, as spatially continuous data for mapping and for comparison between seasons and years. Interpolation methods examined in this study include ordinary kriging with five different semivariance models combined with a variable number of neighboring points, the inverse distance weighted (IDW) method with different parameters, and the triangulated irregular network (TIN) method with linear and quintic options. Interpolation results were compared with survey data at selected calibration transects to examine the suitability of different interpolation methods. Suitability was quantified by the determination coefficient (R2) and the root-mean-square error (RMSE) between interpolated and observed values. The most suitable interpolation method was identified as the one yielding the highest R2 value and/or the lowest RMSE value. For different geographic conditions, seasons, and SAV parameters, different interpolation methods were recommended. This study identified that kriging was more suitable than the IDW or TIN method for spatial interpolation of all SAV parameters measured. It also suggested that transect data with irregular spatial distribution patterns such as SAV parameters are sensitive to interpolation methods. An inappropriate interpolation method such as TIN can lead to erroneous spatial representation of the SAV status. With a functional geographic system and adequate computing power, the evaluation and selection of interpolation methods can be automated and quantitative, leading to a more efficient and accurate decision.     

Mapping Submerged Aquatic Vegetation with GIS in the Caloosahatchee Estuary: Evaluation of Different Interpolation Methods

This article evaluates different spatial interpolation methods for mapping submerged aquatic vegetation (SAV) in the Caloosahatchee Estuary, Florida. Data used for interpolation were collected by the Submersed Aquatic Vegetation Early Warning System (SAVEWS). The system consists of hydro-acoustic equipment, which operates from a slow-moving boat and records bottom depth, seagrass height, and seagrass density. This information is coupled with geographic location coordinates from a Global Positioning System (GPS) and stored together in digital files, representing SAV status at points along transect lines. Adequate spatial interpolation is needed to present the SAV information, including density, height, and water depth, as spatially continuous data for mapping and for comparison between seasons and years. Interpolation methods examined in this study include ordinary kriging with five different semivariance models combined with a variable number of neighboring points, the inverse distance weighted (IDW) method with different parameters, and the triangulated irregular network (TIN) method with linear and quintic options. Interpolation results were compared with survey data at selected calibration transects to examine the suitability of different interpolation methods. Suitability was quantified by the determination coefficient (R2) and the root-mean-square error (RMSE) between interpolated and observed values. The most suitable interpolation method was identified as the one yielding the highest R2 value and/or the lowest RMSE value. For different geographic conditions, seasons, and SAV parameters, different interpolation methods were recommended. This study identified that kriging was more suitable than the IDW or TIN method for spatial interpolation of all SAV parameters measured. It also suggested that transect data with irregular spatial distribution patterns such as SAV parameters are sensitive to interpolation methods. An inappropriate interpolation method such as TIN can lead to erroneous spatial representation of the SAV status. With a functional geographic system and adequate computing power, the evaluation and selection of interpolation methods can be automated and quantitative, leading to a more efficient and accurate decision.     

地理信息系统在海岸海洋地貌研究中的应用

随着现代海洋观测技术的发展,通过海岸海洋地貌调查获得的数据急剧增长。运用地理信息系统(GIS)将不同学科、不同来源、不同格式的数据进行集成管理、分析和表达已成为当前海岸海洋地貌研究的重点。系统介绍了GIS技术在海岸海洋地貌研究中新的方法体系,包括数据获取、数据处理、数据分析和数据表达四个部分,重点研究了GIS空间技术、海底地形建模和用三维可视化技术解译海洋地学,探索陆海交互作用中隐含信息的方法,并将其应用到沿海城市规划、海港选址、大陆架岛礁地貌环境研究的具体实例中,研究范围从陆到海涵盖整个海陆交互作用带,为海岸海洋社会发展、经济建设及外交权益提供科学基础和决策支持。通过上述方法体系与应用研究说明,以GIS为核心建立的多源地理空间信息平台使传统海岸海洋地貌研究的范围、内容及方法都发生了重大变化,但多源数据信息的精确解译和成功应用必须同时具有空间信息学和地貌学专家知识。     

完备格上的表现定理及其应用

在完备格的条件下讨论了Ｌ集合套的性质,给出了表现定理,最后指出了表现定理在ＬＦ代数理论中的应用。     

Naval Mine Impact Burial Prediction using Seafloor Database,Experiment, and GIS Technologies

The possibility of naval mines buried in the seafloor poses difficulties for navies concerned with port and seaway operations. To devise countermeasures, predictions of degrees of impact burial over wide areas of seabed must be made. Under ideal conditions, this is done with a knowledge of local seabed shear strengths, but in practice, such data are rarely available.

We describe an alternative prediction method. Probabilistic predictions of mine impact burial are made across areas of variable seafloor by combining data on sedimentary character directly with experimental impact burial results. The most useful seafloor characteristics are mud content and consolidation. The predictions are relatively accurate (SD 1–22%), and are computable in detail over wide geographic areas. They are of a form immediately useful for naval operations (including calculations of risk) and are easily displayed in geographic information systems (GIS). An example is shown for the northern Gulf of Mexico.     

Naval Mine Impact Burial Prediction using Seafloor Database, Experiment, and GIS Technologies

The possibility of naval mines buried in the seafloor poses difficulties for navies concerned with port and seaway operations. To devise countermeasures, predictions of degrees of impact burial over wide areas of seabed must be made. Under ideal conditions, this is done with a knowledge of local seabed shear strengths, but in practice, such data are rarely available.

We describe an alternative prediction method. Probabilistic predictions of mine impact burial are made across areas of variable seafloor by combining data on sedimentary character directly with experimental impact burial results. The most useful seafloor characteristics are mud content and consolidation. The predictions are relatively accurate (SD 1-22%), and are computable in detail over wide geographic areas. They are of a form immediately useful for naval operations (including calculations of risk) and are easily displayed in geographic information systems (GIS). An example is shown for the northern Gulf of Mexico.     

渤海区域地质信息管理系统数据模型

以渤海区域地质信息管理系统数据模型为例,阐述了基于GIS的海洋地学管理信息系统中数据的组织方法,包括数据分类、分层方案、命名及编码规则、空间数据库和属性数据库的建设以及两者之间的关系.通过设置基础表,解决了系统中说明性信息难以代码化的难题,并在此基础上设计了系统的数据模型.     

基于转换模式的多源数字海图融合研究

数据融合是实现多源数字地图共享利用的途径之一,从制图要素空间位置融合、地理实体分类分级编码融合、数字地图空间数据模型融合等三个方面对基于转换模式的多源数字海图融合理论和方法做出分析与探讨。     

南海诸岛地理实体及其名称研究

分析了南海诸岛地名的历史和现状,通过比对历史资料和现代精细化海洋测量数据,发现了南海诸岛地理实体特征与其名称关系匹配存在的不足.归纳总结了4个方面问题:①地名指代地理实体的范围不明确或不合理;②部分地理实体名称未对外公布;③新发现的地理实体未被命名;④部分不存在的地理实体未被销名.通过列举多个地名的使用情况,基于精细化...