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Algebraic encoding scheme for aperture 3 hexagonal discrete global grid system 被引量:5
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作者 BEN Jin LI YaLu +2 位作者 ZHOU ChengHu WANG Rui DU LingYu 《Science China Earth Sciences》 SCIE EI CAS CSCD 2018年第2期215-227,共13页
Discrete Global Grid Systems(DGGSs) are spatial references that use a hierarchical tessellation of cells to partition and address the entire globe. They provide an organizational structure that permits fast integratio... Discrete Global Grid Systems(DGGSs) are spatial references that use a hierarchical tessellation of cells to partition and address the entire globe. They provide an organizational structure that permits fast integration between multiple sources of large and variable geospatial data sufficient for visualization and analysis. Despite a significant body of research supporting hexagonal DGGSs as the superior choice, the application thereof has been hindered owing in part to the lack of a rational hierarchy with an efficient addressing system. This paper presents an algebraic model of encoding scheme for the Aperture 3 Hexagonal(A3H) DGGS. Firstly, the definition of a grid cell, which is composed of vertices, edges, and a center, is introduced to describe fundamental elements of grids. Secondly, by identifying the grid cell with its center, this paper proves that cell centers at different levels can be represented exactly using a mixed positional number system in the complex plane through the recursive geometric relationship between two successive levels, which reveals that grid cells are essentially special complex radix numbers. Thirdly, it is shown that through the recursive geometric relationship of successive odd or even levels, the mixed positional number system can also be applied to uniquely represent cell centers at different levels under specific constraint conditions, according to which the encoding scheme is designed. Finally, it is shown that by extending the scheme to 20 triangular faces of the regular icosahedron,multi-resolution grids on closed surfaces of the icosahedron are addressed perfectly. Contrast experiments show that the proposed encoding scheme has the advantages of theoretical rigor and high programming efficiency and that the efficiency of cross-face adjacent cell searching is 242.9 times that of a similar scheme. Moreover, the proposed complex radix number representation is an ideal formalized description tool for grid systems. The research ideas introduced herein can be used to create a universal theoretical framework for DGGSs. 展开更多
关键词 Discrete global grid system HEXAGON Positional number system Algebraic encoding
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GIScience research challenges for realizing discrete global grid systems as a Digital Earth 被引量:5
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作者 Majid Hojati Colin Robertson +1 位作者 Steven Roberts Chiranjib Chaudhuri 《Big Earth Data》 EI 2022年第3期358-379,共22页
Increasing data resources are available for documenting and detecting changes in environmental,ecological,and socioeconomic processes.Currently,data are distributed across a wide variety of sources(e.g.data silos)and ... Increasing data resources are available for documenting and detecting changes in environmental,ecological,and socioeconomic processes.Currently,data are distributed across a wide variety of sources(e.g.data silos)and published in a variety of formats,scales,and semantic representations.A key issue,therefore,in building systems that can realize a vision of earth system monitoring remains data integration.Discrete global grid systems(DGGSs)have emerged as a key technology that can provide a common multi-resolution spatial fabric in support of Digital Earth monitoring.However,DGGSs remain in their infancy with many technical,conceptual,and operational challenges.With renewed interest in DGGS brought on by a recently proposed standard,the demands of big data,and growing needs for monitoring environmental changes across a variety of scales,we seek to highlight current challenges that we see as central to moving the field(s)and technologies of DGGS forward.For each of the identified challenges,we illustrate the issue and provide a potential solution using a reference DGGS implementation.Through articulation of these challenges,we hope to identify a clear research agenda,expand the DGGS research footprint,and provide some ideas for moving forward towards a scaleable Digital Earth vision.Addressing such challenges helps the GIScience research community to achieve the real benefits of DGGS and provides DGGS an opportunity to play a role in the next generation of GIS. 展开更多
关键词 DGGS discrete global grid systems GISCIENCE Digital Earth
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Intelligent geospatial maritime risk analytics using the Discrete Global Grid System 被引量:4
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作者 Andrew Rawson Zoheir Sabeur Mario Brito 《Big Earth Data》 EI 2022年第3期294-322,共29页
Each year,accidents involving ships result in significant loss of life,environmental pollution and economic losses.The promotion of navigation safety through risk reduction requires methods to assess the spatial distr... Each year,accidents involving ships result in significant loss of life,environmental pollution and economic losses.The promotion of navigation safety through risk reduction requires methods to assess the spatial distribution of the relative likelihood of occurrence.Yet,such methods necessitate the integration of large volumes of heterogenous datasets which are not well suited to traditional data structures.This paper proposes the use of the Discrete Global Grid System(DGGS)as an efficient and advantageous structure to integrate vessel traffic,metocean,bathymetric,infrastructure and other relevant maritime datasets to predict the occurrence of ship groundings.Massive and heterogenous datasets are well suited for machine learning algorithms and this paper develops a spatial maritime risk model based on a DGGS utilising such an approach.A Random Forest algorithm is developed to predict the frequency and spatial distribution of groundings while achieving an R2 of 0.55 and a mean squared error of 0.002.The resulting risk maps are useful for decision-makers in planning the allocation of mitigation measures,targeted to regions with the highest risk.Further work is identified to expand the applications and insights which could be achieved through establishing a DGGS as a global maritime spatial data structure. 展开更多
关键词 Maritime risk Discrete global grid system big data machine learning
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Spatial prediction of sparse events using a discrete global grid system;a case study of hate crimes in the USA 被引量:2
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作者 Michael Jendryke Stephen C.McClure 《International Journal of Digital Earth》 SCIE 2021年第6期789-805,共17页
Spatial prediction of any geographic phenomenon can be an intractable problem.Predicting sparse and uncertain spatial events related to many influencing factors necessitates the integration of multiple data sources.We... Spatial prediction of any geographic phenomenon can be an intractable problem.Predicting sparse and uncertain spatial events related to many influencing factors necessitates the integration of multiple data sources.We present an innovative approach that combines data in a Discrete Global Grid System(DGGS)and uses machine learning for analysis.A DGGS provides a structured input for multiple types of spatial data,consistent over multiple scales.This data framework facilitates the training of an Artificial Neural Network(ANN)to map and predict a phenomenon.Spatial lag regression models(SLRM)are used to evaluate and rank the outputs of the ANN.In our case study,we predict hate crimes in the USA.Hate crimes get attention from mass media and the scientific community,but data on such events is sparse.We trained the ANN with data ingested in the DGGS based on a 50%sample of hate crimes as identified by the Southern Poverty Law Center(SPLC).Our spatial prediction is up to 78%accurate and verified at the state level against the independent FBI hate crime statistics with a fit of 80%.The derived risk maps are a guide to action for policy makers and law enforcement. 展开更多
关键词 Discrete global grid system geospatial data integration artificial neural network spatial prediction sparse events hates crimes
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A novel method of determining the optimal polyhedral orientation for discrete global grid systems applicable to regionalscale areas of interest 被引量:2
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作者 Jianbin Zhou Jin Ben +3 位作者 Rui Wang Mingyang Zheng Xiaochuang Yao Lingyu Du 《International Journal of Digital Earth》 SCIE 2020年第12期1553-1569,共17页
The polyhedral discrete global grid system(DGGS)is a multi-resolution discrete earth reference model supporting the fusion and processing of multi-source geospatial information.The orientation of the polyhedron relati... The polyhedral discrete global grid system(DGGS)is a multi-resolution discrete earth reference model supporting the fusion and processing of multi-source geospatial information.The orientation of the polyhedron relative to the earth is one of its key design choices,used when constructing the grid system,as the efficiency of indexing will decrease if local areas of interest extend over multiple faces of the spherical polyhedron.To date,most research has focused on global-scale applications while almost no rigorous mathematical models have been established for determining orientation parameters.In this paper,we propose a method for determining the optimal polyhedral orientation of DGGSs for areas of interest on a regional scale.The proposed method avoids splitting local or regional target areas across multiple polyhedral faces.At the same time,it effectively handles geospatial data at a global scale because of the inherent characteristics of DGGSs.Results show that the orientation determined by this method successfully guarantees that target areas are located at the center of a single polyhedral face.The orientation process determined by this novel method reduces distortions and is more adaptable to different geographical areas,scales,and base polyhedrons than those employed by existing procedures. 展开更多
关键词 Discrete global grid systems single polyhedral face convex polygons rotate and translate cost function
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EASE-DGGS:a hybrid discrete global grid system for Earth sciences 被引量:2
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作者 Jeffery A.Thompson Mary J.Brodzik +2 位作者 Kevin A.T.Silverstein Mason A.Hurley Nathan L.Carlson 《Big Earth Data》 EI 2022年第3期340-357,共18页
Although we live in an era of unprecedented quantities and access to data,deriving actionable information from raw data is a hard problem.Earth observation systems(EOS)have experienced rapid growth and uptake in recen... Although we live in an era of unprecedented quantities and access to data,deriving actionable information from raw data is a hard problem.Earth observation systems(EOS)have experienced rapid growth and uptake in recent decades,and the rate at which we obtain remotely sensed images is increasing.While significant effort and attention has been devoted to designing systems that deliver analytics ready imagery faster,less attention has been devoted to developing analytical frameworks that enable EOS to be seamlessly integrated with other data for quantitative analysis.Discrete global grid systems(DGGS)have been proposed as one potential solution that addresses the challenge of geospatial data integration and interoperability.Here,we propose the systematic extension of EASE-Grid in order to provide DGGS-like characteristics for EOS data sets.We describe the extensions as well as present implementation as an application programming interface(API),which forms part of the University of Minnesota’s GEMS(Genetic x Environment x Management x Socioeconomic)Informatics Center’s API portfolio. 展开更多
关键词 Discrete global grid systems DGGS EASE grid coordinate reference systems
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Construction of rhombic triacontahedron discrete global grid systems 被引量:1
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作者 Xiaoyu Liang Jin Ben +3 位作者 Rui Wang Qishuang Liang Xinhai Huang Junjie Ding 《International Journal of Digital Earth》 SCIE EI 2022年第1期1760-1783,共24页
Discrete Global Grid System(DGGS)is a new multi-resolution geospatial data modeling and processing scheme for the digital earth.The icosahedron is commonly regarded as an ideal polyhedron for constructing DGGSs with s... Discrete Global Grid System(DGGS)is a new multi-resolution geospatial data modeling and processing scheme for the digital earth.The icosahedron is commonly regarded as an ideal polyhedron for constructing DGGSs with small distortions;however,the shape of its face is triangular,making it difficult to incorporate the matrix structure used for geospatial data storage and parallel computing.To overcome this limitation,this study utilizes the rhombic triacontahedron(RT)as the basic polyhedron to construct DGGSs.An equal-area projection between the surface of RT and the sphere is developed and used to design a grid-generation algorithm for the aperture 4 hexagonal DGGS based on RT.Compared with the equal-area DGGS based on the icosahedron,the proposed scheme results in smaller angular projection distortions,with the mean and standard deviation decreasing by 41.6%and 30.9%,respectively.The grid cells of the RT DGGS also achieve more optimized geometric characteristics in shape compactness,length deviation,and angle deviation than those in the icosahedron DGGS.Additionally,the cross-surface computation efficiency provides advantages in code conversion to latitude and longitude and proximity queries.Furthermore,the use of RT offers a new and better framework within the context of DGGS research and application. 展开更多
关键词 Discrete global grid system rhombic triacontahedron equal-area projection HEXAGON
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An open-source web service for creating quadrilateral grids based on the rHEALPix Discrete Global Grid System
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作者 David Bowater Emmanuel Stefanakis 《International Journal of Digital Earth》 SCIE 2020年第9期1055-1071,共17页
The foundation of modern Digital Earth frameworks is the Discrete Global Grid System(DGGS).To standardize the DGGS model,the Open Geospatial Consortium(OGC)recently created the DGGS Abstract Specification,which also a... The foundation of modern Digital Earth frameworks is the Discrete Global Grid System(DGGS).To standardize the DGGS model,the Open Geospatial Consortium(OGC)recently created the DGGS Abstract Specification,which also aims to increase usability and interoperability between DGGSs.To support these demands and aid future research,open implementations are necessary.However,several OGC conformant DGGSs are not available for researchers to use.This has motivated us to develop an open-source web service that allows users to create quadrilateral grids based on the rHEALPix DGGS.In this paper,we describe the implementation of the web service,including issues and limitations,and demonstrate how discrete global grids and regional grids can be created.Lastly,we present examples that show how vector data sets can be modeled and integrated at different levels of resolution–a key benefit of the DGGS model. 展开更多
关键词 Quadrilateral grid rHEALPix Discrete global grid system Digital Earth web service
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On the isolatitude property of the rHEALPix Discrete Global Grid System
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作者 David Bowater Emmanuel Stefanakis 《Big Earth Data》 EI 2019年第4期362-377,共16页
Digital Earth frameworks provide a way to integrate,analyze,and visualize large volumes of geospatial data,and the foundation of such frameworks is the Discrete Global Grid System(DGGS).One approach in particular,the ... Digital Earth frameworks provide a way to integrate,analyze,and visualize large volumes of geospatial data,and the foundation of such frameworks is the Discrete Global Grid System(DGGS).One approach in particular,the rHEALPix DGGS,has the rare property of distribution of cell nuclei along rings of constant latitude(or isolatitude rings).However,this property is yet to be explored.In this paper,we extend existing work on the rHEALPix DGGS by proposing a method to determine the isolatitude ring on which the nucleus of a given cell falls by converting a cell identifier to isolatitude ring without recourse to geodetic coordinates.In addition,we present an efficient method to calculate the geodetic latitude of a cell’s nucleus via its associated isolatitude ring.Lastly,we use the proposed methods to demonstrate how the isolatitude property of the rHEALPix DGGS can be utilized to facilitate latitudinal data analysis at multiple resolutions. 展开更多
关键词 rHEALPix Discrete global grid system isolatitude property latitudinal data analysis Digital Earth geospatial big data
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An optimized hexagonal quadtree encoding and operation scheme for icosahedral hexagonal discrete global grid systems
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作者 Long Zhao Guoqing Li +2 位作者 Xiaochuang Yao Yue Ma Qianqian Cao 《International Journal of Digital Earth》 SCIE EI 2022年第1期975-1000,共26页
Although research on the discrete global grid systems (DGGSs) has become an essential issue in the era of big earth data,there is still a gap between the efficiency of current encoding and operation schemes for hexago... Although research on the discrete global grid systems (DGGSs) has become an essential issue in the era of big earth data,there is still a gap between the efficiency of current encoding and operation schemes for hexagonal DGGSs and the needs of practical applications. This paper proposes a novel and efficient encoding and operation scheme of an optimized hexagonal quadtree structure (OHQS) based on aperture 4 hexagonal discrete global grid systems by translation transformation. A vector model is established to describe and calculate the aperture 4 hexagonal grid system. This paper also provides two different grid code addition algorithms based on induction and ijk coordinate transformation. We implement the transformation between OHQS codes and geographic coordinates through the ij,ijk and IJK coordinate systems. Compared with existing schemes,the scheme in this paper greatly improves the efficiency of the addition operation,neighborhood retrieval and coordinate transformation,and the coding is more concise than other aperture 4 hexagonal DGGSs. The encoding operation based on the ijk coordinate system is faster than the encoding operation based on the induction and addition table. Spatial modeling based OHQS DGGSs are also provided. A case study with rainstorms demonstrated the availability of this scheme. 展开更多
关键词 Discrete global grid systems HEXAGON quadtree encoding
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Assessment of Crop Yield in China Simulated by Thirteen Global Gridded Crop Models
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作者 Dezhen YIN Fang LI +3 位作者 Yaqiong LU Xiaodong ZENG Zhongda LIN Yanqing ZHOU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第3期420-434,共15页
Global gridded crop models(GGCMs) have been broadly applied to assess the impacts of climate and environmental change and adaptation on agricultural production. China is a major grain producing country, but thus far o... Global gridded crop models(GGCMs) have been broadly applied to assess the impacts of climate and environmental change and adaptation on agricultural production. China is a major grain producing country, but thus far only a few studies have assessed the performance of GGCMs in China, and these studies mainly focused on the average and interannual variability of national and regional yields. Here, a systematic national-and provincial-scale evaluation of the simulations by13 GGCMs [12 from the GGCM Intercomparison(GGCMI) project, phase 1, and CLM5-crop] of the yields of four crops(wheat, maize, rice, and soybean) in China during 1980–2009 was carried out through comparison with crop yield statistics collected from the National Bureau of Statistics of China. Results showed that GGCMI models generally underestimate the national yield of rice but overestimate it for the other three crops, while CLM5-crop can reproduce the national yields of wheat, maize, and rice well. Most GGCMs struggle to simulate the spatial patterns of crop yields. In terms of temporal variability, GGCMI models generally fail to capture the observed significant increases, but some can skillfully simulate the interannual variability. Conversely, CLM5-crop can represent the increases in wheat, maize, and rice, but works less well in simulating the interannual variability. At least one model can skillfully reproduce the temporal variability of yields in the top-10 producing provinces in China, albeit with a few exceptions. This study, for the first time, provides a complete picture of GGCM performance in China, which is important for GGCM development and understanding the reliability and uncertainty of national-and provincial-scale crop yield prediction in China. 展开更多
关键词 global gridded crop model historical crop yield China multi-model evaluation
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Construction of quality evaluation indicator system for diamond discrete global grid systems
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作者 Fuli Luo Shupeng Gao +3 位作者 Xinpeng Wang Aimei Chen Zheng Wang Yalu Li 《International Journal of Digital Earth》 SCIE EI 2023年第1期3637-3660,共24页
Although the uniformity of diamond discrete global grid is essential for calculations and searches,geometric deformations increase with the level of divisions.The Good child Criteria provides a basis for evaluating th... Although the uniformity of diamond discrete global grid is essential for calculations and searches,geometric deformations increase with the level of divisions.The Good child Criteria provides a basis for evaluating the quality of the global grid.However,some indicators in the criteria are redundant and contradictory,and the existing indicator system has limitations.Directly using the indicator system may render the evaluation of the diamond grid unreliable.In this study,we summarized the evaluation indicators for grid quality basedon the Good child Criteria,calculated the correlations between these indicators using different diamond grid systems,and constructed reliable evaluation systems based on similarities and differences.The selected grid systems are classified into two groups:non-equal-area and equal-area grids.Their quality evaluation systems are composed of Size-Shape-Topology Factor and Geometry-Topology Factor,respectively.The proposed quality evaluation systems utilize a minimal number of indicators selected from each factor to provide a comprehensive description of the diamondgrid’s characteristics.This approach simplifies the complexity of the evaluations while improving their reliability and credibility. 展开更多
关键词 discrete global grid goodchild criteria CORRELATION factor analysis diamond grid
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Global Multi-resolution Half-Honeycomb Trapezoid Grid
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作者 XIE Wen-jun LU Jing-ting LIU Xiao-ping 《Computer Aided Drafting,Design and Manufacturing》 2014年第4期14-19,共6页
In order to break through the limitationof thelatitude/longitudegrid and hexagon grid, a new subdivision unit, Half-honeycomb Trapezoid, is proposed. Based on the summarization of the geometric properties and subdivis... In order to break through the limitationof thelatitude/longitudegrid and hexagon grid, a new subdivision unit, Half-honeycomb Trapezoid, is proposed. Based on the summarization of the geometric properties and subdivision performance of Half-honeycomb Trapezoid, a new discrete global topographic grid system is established, and its compatibility with hexagonal grid is analyzed. At last, the visualization of multi-resolution global grid is achieved. 展开更多
关键词 discrete global grid MULTI-RESOLUTION half-honeycomb trapezoid
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Global GIS及其关键技术 被引量:11
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作者 孙敏 赵学胜 赵仁亮 《武汉大学学报(信息科学版)》 EI CSCD 北大核心 2008年第1期41-45,71,共6页
Global GIS(全球性地理信息系统,GGIS)的研究近年来变得日益重要,基于对目前研究现状所做的分析和评述,指出了构建基于统一三维地心参考系并以地球椭球体模型为依托的多层次格网框架是GGIS研究的基础,并且在全球性多源多尺度空间数据集... Global GIS(全球性地理信息系统,GGIS)的研究近年来变得日益重要,基于对目前研究现状所做的分析和评述,指出了构建基于统一三维地心参考系并以地球椭球体模型为依托的多层次格网框架是GGIS研究的基础,并且在全球性多源多尺度空间数据集成、三维椭球面空间数据表达以及多层次格网编码与索引技术等方面均存在着一系列理论与技术问题有待解决,分析了这些问题的难点所在,并给出了一些参考性的解决方案。 展开更多
关键词 globalGIS GIS 球面格网 统一地心参考系
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A Novel Architecture of Metadata Management System Based on Intelligent Cache 被引量:1
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作者 SONG Baoyan ZHAO Hongwei +2 位作者 WANG Yan GAO Nan XU Jin 《Wuhan University Journal of Natural Sciences》 CAS 2006年第5期1222-1226,共5页
This paper introduces a novel architecture of metadata management system based on intelligent cache called Metadata Intelligent Cache Controller (MICC). By using an intelligent cache to control the metadata system, ... This paper introduces a novel architecture of metadata management system based on intelligent cache called Metadata Intelligent Cache Controller (MICC). By using an intelligent cache to control the metadata system, MICC can deal with different scenarios such as splitting and merging of queries into sub-queries for available metadata sets in local, in order to reduce access time of remote queries. Application can find results patially from local cache and the remaining portion of the metadata that can be fetched from remote locations. Using the existing metadata, it can not only enhance the fault tolerance and load balancing of system effectively, but also improve the efficiency of access while ensuring the access quality. 展开更多
关键词 data grid global name system (GNS) intelligent cache ntegration data web services resource framework (WSRF)
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地理空间数据等积全球格网多模式三维扩展方法 被引量:1
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作者 周建彬 丁俊杰 +2 位作者 贲进 陈艺航 梁启爽 《测绘学报》 EI CSCD 北大核心 2024年第1期173-188,共16页
全球离散格网系统是新型地理空间数据组织框架,等面积格网由于在采样和空间分析方面的独特优势而备受关注,但相关研究囿于地球表面,缺乏扩展至三维广域空间的一般方法。本文首先提出将等积球面格网系统扩展为球体格网系统的多种剖分模式... 全球离散格网系统是新型地理空间数据组织框架,等面积格网由于在采样和空间分析方面的独特优势而备受关注,但相关研究囿于地球表面,缺乏扩展至三维广域空间的一般方法。本文首先提出将等积球面格网系统扩展为球体格网系统的多种剖分模式,并实现其统一数学描述和详细数学证明;然后引入体积和紧致度指标定量评价不同剖分模式的体元性质,并与球体退化八叉树格网(SDOG)、大圆弧八叉树格网(SGOG)作对比;最后初步探索了本文方法的应用案例,讨论了不同应用需求下选择剖分模式的原则。对比试验结果表明,退化剖分的体元各项指标均优于规则剖分,等体积和退化剖分的体积性质优于SDOG,紧致度性质优于SGOG。本文多剖分模式三维扩展方法不仅符合国际标准等体积的要求,而且兼顾常规剖分设计选项,为不同应用需求提供了参考依据。 展开更多
关键词 等面积 全球离散格网系统 三维扩展 剖分 等体积 紧致度
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电网机械终端防跌落抖动的滑膜控制方法研究
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作者 付佳佳 刘彩霞 胡毅 《自动化仪表》 CAS 2024年第8期27-31,共5页
由于自动兼容式电网的结构复杂,机械终端轨迹到达滑动模态面后难以严格沿着滑动模态面向平衡点滑动,导致电压和功率突变跌落而产生抖动。对此,提出自动兼容式电网机械终端防跌落抖动的滑膜控制方法。构建机械终端数学模型,分析产生跌落... 由于自动兼容式电网的结构复杂,机械终端轨迹到达滑动模态面后难以严格沿着滑动模态面向平衡点滑动,导致电压和功率突变跌落而产生抖动。对此,提出自动兼容式电网机械终端防跌落抖动的滑膜控制方法。构建机械终端数学模型,分析产生跌落抖动问题的原因。提出基于扩张观测器的滑膜控制方法,设计扩张观测器,以获取机械终端系统内部扰动信息。将观测结果用作电流前馈补偿,以优化抗干扰性。结合滑膜控制方法设计滑膜控制器,通过该控制器实现自动兼容式电网机械终端滑膜控制。试验结果表明,该方法的电流功率突变动态波动情况平稳,电网电压跌落85%后恢复至正常电压的速度较快。该方法缓解了跌落抖动程度,有效提高了动态响应波动稳定性,并促进了配电网的发展。 展开更多
关键词 自动兼容式电网 机械终端系统 滑膜控制 扩张观测器 全局滑动模态
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球面等积网格系统生成算法与软件模型研究 被引量:22
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作者 贲进 童晓冲 +1 位作者 张永生 陈荣国 《测绘学报》 EI CSCD 北大核心 2007年第2期187-191,共5页
利用全球离散网格系统管理海量空间信息是一种受到普遍关注的新途径,具有等积特性的网格系统在大范围遥感影像数据处理方面具有重要的理论意义和应用前景。文中论述的算法在二十面体展开图上建立坐标系描述不同剖分产生的多分辨率网格,... 利用全球离散网格系统管理海量空间信息是一种受到普遍关注的新途径,具有等积特性的网格系统在大范围遥感影像数据处理方面具有重要的理论意义和应用前景。文中论述的算法在二十面体展开图上建立坐标系描述不同剖分产生的多分辨率网格,利用施奈德多面体投影映射到球面。针对算法特点设计具有网络模拟功能的软件模型。实验结果表明,该软件模型具有较好的扩展性。 展开更多
关键词 等积 球面网格系统 算法 软件模型
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基于全球离散网格框架的局部网格划分 被引量:18
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作者 童晓冲 贲进 +1 位作者 秦志远 张永生 《测绘学报》 EI CSCD 北大核心 2009年第6期506-513,共8页
从全球离散网格系统的应用需求出发,分析全球框架下建立局部网格的重要性,在此基础上提出全球离散网格系统下同构化的局部网格生成的基本思路,详细分析局部网格的复杂球面边界问题,从点与球面三角形的位置关系入手,讨论点与任意球面多... 从全球离散网格系统的应用需求出发,分析全球框架下建立局部网格的重要性,在此基础上提出全球离散网格系统下同构化的局部网格生成的基本思路,详细分析局部网格的复杂球面边界问题,从点与球面三角形的位置关系入手,讨论点与任意球面多边形的相对位置关系,研究基于球面任意多边形的边缘简化算法、判断点与球面任意多边形相互关系的算法、考虑跨面问题的网格区域裁减以及网格数据的层次生成算法。通过实验证明这些方法的效率和准确性。 展开更多
关键词 全球离散网格系统 局部网格 区域裁减 层次数据
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全球多分辨率六边形网格剖分及地址编码规则 被引量:17
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作者 童晓冲 贲进 张永生 《测绘学报》 EI CSCD 北大核心 2007年第4期428-435,共8页
首先介绍全球网格系统的应用需求,讨论采用正多面体剖分的基本要素。在此基础上,提出一种新型的便于存储,具有多分辨率层次索引、管理能力的六边形剖分全球网格系统的设计思路、产生步骤和生成算法。分析现有六边形索引机制的缺陷,给出... 首先介绍全球网格系统的应用需求,讨论采用正多面体剖分的基本要素。在此基础上,提出一种新型的便于存储,具有多分辨率层次索引、管理能力的六边形剖分全球网格系统的设计思路、产生步骤和生成算法。分析现有六边形索引机制的缺陷,给出一种新的球面六边形网格层次结构,在该结构的基础上设计网格的层次化编码方式,成功建立网格的编码空间,详细探讨经纬度坐标与网格地址编码的转换问题,给出并实现基于递归层次离散网格坐标系统的互换算法,严格保证计算的准确性和可靠性。该结构能够无缝地表达和处理不同分辨率的全球网格空间数据。 展开更多
关键词 全球网格系统 分辨率 编码空间 层次结构
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