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Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geography & Geographic Information Science is the property of Geography & Geo-Information Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: The discrete global grid system (DGGS) is a preferred solution in supporting the fusion processing of multi-source geospatial information. The research of hexagonal gird systems has raised wide academic concern. Compared with global grids, the requirements for regional-scale grid application are more extensive, which has been one of the important issues in current hexagonal DGGS research. It combines two adjacent triangle facets of an icosahedron into a logical quad structure, and based on this structure, an algorithm of generating the multi-aperture hexagonal grid systems with regional-scale is proposed.Methods: Firstly, the grid type is analyzed to establish a discrete integer coordinate system and the spatial location of the multi-aperture hexagonal grid cell is described. Secondly, the regional-scale is split based on the logical quad structure on the surface of the spherical icosahedron to create sub-areas. Thirdly, according to the boundary of the sub-area, an external minimum logical quad structure algorithm is designed to eliminate irrelevant cells on the logical quad structure. Finally, the minimum logical quad structure is traversed to generate a multi-aperture partial grid.Results and Conclusions: The comparative experimental results show that the proposed algorithm has the advantages of better flexibility and higher efficiency. The generated grid is used for the organization of raster data, which can significantly reduce the amount of data and has good application potential. [ABSTRACT FROM AUTHOR]

Vector is an important type of geospatial data, discretization is an important link for its fusion with raster data, and the generation of the discrete line is the basic problem. In view of the shortcomings of discrete line generation algorithm of triangular grid, this paper proposes a mathematical model for establishing the equivalent triangle grid discrete line mathematical model by means of the weak duality hexagonal grid and solving it by dimensionality reduction. Firstly, according to the weak duality relationship between the triangular grids and the hexagonal grids, an equivalent triangular grid discrete line model is established based on the hexagonal grids. Then, using the dimension reduction method, the two‐dimensional discrete line model is equivalently transformed into a one‐dimensional closed path solution. Finally, a discrete triangle conversion generation algorithm for planar triangular grids is designed and implemented. The experimental results show that the proposed algorithm is ingenious and rigorous in theory and beneficial to the programming. The operation efficiency is about 9‐10 times of the similar algorithms, with a better result. This algorithm can be applied to vector data in real‐time grid transformation, terrain modeling, spatial analysis, simulation and other fields,with broad application prospects. [ABSTRACT FROM AUTHOR]

Discrete global grid systems(DGGS) are digital reference models with multi‐resolution for earth and its structure supports the fusion processing of multi ‐ source geospatial information. The icosahedral DGGS have aroused wide attention for their excellent geometric properties and the research difficulty is the code operation scheme for the spherical hexagonal grid system currently. It is proved that DGGS based on the regular polyhedrons are topologically equivalent to the relative regular polyhedral grid systems and their schemes for code operation are topologically equivalent as well. According to this, combining the characteristics of the aperture 4 hexagonal grid system on the surface of the icosahedron， this paper defines vertex tile and face tile based on hexagon lattice quad tree and proposes the code operation scheme for the icosahedral aperture 4 hexagonal grid system. This scheme realizes the cross‐face operation of cells using code operation with high efficiency and overcomes the drawback of existing schemes brought by the use of floating numbers for cross‐face operation with low efficiency. In addition， the search efficiency for cross‐face adjacent cells is about 19.6 times that of hexagonal quad balanced structure. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)