A hexagonal grid construction method for remote sensing satellite regional observation task

Abstract

The application discloses a hexagon grid construction method for remote sensing satellite regional observation tasks, and the steps include: 1) constructing a spherical icosahedron-based spherical hexagon map grid subdivision model of a digital earth, wherein the 0th layer of the spherical hexagon map grid subdivision model is used for subdividing the earth surface through n hexagons and H p pentagonal grid units, so as to obtain the 0th layer digital grid map of the digital earth, the center point coordinates and the vertex coordinate values of each hexagon grid and pentagonal grid are fixed, and the side lengths of the hexagon grid and the pentagonal grid are equal; then, the center point coordinates and the vertex coordinate values of the hexagon grid and the pentagonal grid in each layer digital grid map from the first layer to the highest layer of the spherical hexagon grid subdivision model are calculated according to a set rule, so as to obtain the digital grid map of the corresponding layer of the digital earth; 2) establishing a spherical hexagon grid space index; and 3) generating a large-range regional grid quickly.

Description

Technical Field

[0001] This invention relates to the field of grid map construction technology related to aerospace system simulation, specifically a hexagonal grid construction method for remote sensing satellite regional observation missions. Background Technology

[0002] Spherical hexagonal mesh generation is a spatial information data model for constructing and managing global multi-scale representations. It primarily studies how to recursively divide the Earth's (reference ellipsoid) surface into a series of mesh graphics with approximately equal area and shape, possessing a multi-resolution hierarchical structure. It has been widely applied in cartography, regional addressing, and route calculation. As can be seen from the concept and applications of spherical hexagonal mesh generation, this method is a core research area, especially in the field of aerospace system simulation. It plays a crucial role in how to uniformly divide the target area to be observed and form a hierarchical mesh structure based on Earth observation satellite regional imaging missions.

[0003] The paper (CHEN, Mengyun, MENG, Xin, PENG, Xiaodong. Method of Geometry Clipmap based on icosahedron [J]. Journal of Remote Sensing, 2014: 1059-1071.) proposes a spherical terrain subdivision and rendering method based on Geometry Clipmap. This method is based on constructing an icosahedral spherical hexagonal mesh, dividing the icosahedron into ten rhombic regions. Using this rhombic mesh subdivision, the surrounding mesh of each rhombic region is re-subdivided and combined to form a virtual 3x3 large rhombic region, expanding the active range of the Clipmap and, to some extent, solving the problem of Clipmap crossing boundaries, such as... Figure 3 As shown. However, its advantages are not obvious in terms of grid representation of target areas at large and multi-scale scales, and address encoding representation of spherical continuous space, which is insufficient to cope with regional imaging tasks of Earth observation satellites.

[0004] The literature (Ben Jin et al. Algorithm for generating hexagonal discrete grid systems based on regular octahedrons [J]. Geographic Information Science, 2015, 17(7):789-797.) studies an algorithm for generating hexagonal discrete grid systems based on regular octahedrons. It belongs to a type of hexagonal grid system generation algorithm, which combines adjacent triangular faces on a regular octahedron into a "quadrilateral logical structure." By establishing a three-axis discrete oblique coordinate system, it describes the multi-resolution grids generated by different hexagonal subdivisions, such as... Figure 4 As shown.

[0005] Compared to other polyhedra, the octahedron has a simpler relative position to the Earth, making coordinate calculation easier; it has fewer triangular faces, making it easier to stitch together elements at the boundaries of adjacent faces; and the even number of triangular faces sharing a vertex is more conducive to establishing a grid measurement system. However, the hexagonal grid system based on the regular octahedron suffers from significant geometric deformation during the mapping process from the polyhedron surface to the sphere, which reduces the accuracy of data processing and representation. Although this can be improved by refining the mapping method or increasing the subdivision level to meet the accuracy requirements of applications, this requires a significant amount of time for algorithm improvement and adaptation. Similarly, its practical value is limited in rapidly generating large-area grid subdivisions for regional imaging missions of Earth observation satellites.

[0006] The literature (Gao Zhen et al. Generation of Voronoi Diagrams in Heterogeneous Space Based on Regular Hexagonal Grid [J]. Geography and Geographic Information Science, 2019, 35(5):52-59.) studies a Voronoi Diagram (VD) based on a regular hexagonal grid. VD is a spatial partitioning geometric structure, which means that each generator must acquire its own space. The competition between adjacent generators for the distribution range causes the space to be divided equally (without considering the differences in the properties of generators, distribution space, etc.), forming a set of spatial spheres of influence of each generator, such as Figure 5 As shown.

[0007] Voronoi diagrams (VDs) possess important characteristics such as spatial proximity, competitive spatial partitioning, and duality with Delaunay triangulation. They are widely used in GIS for spatial analysis, spatial querying, and spatial big data modeling. VDs are often generated based on square grids, but squares lack isotropy, which degrades the accuracy of the generated results and the spatial data modeling capability. This paper employs a heterogeneous spatial Voronoi diagram generation algorithm based on regular hexagonal grids. By improving the grid structure and active pixel growth process, and integrating constraints such as block attributes, generator weights, and external forces, preliminary experiments demonstrate the superiority of regular hexagonal grids in spatial modeling, the effectiveness of heterogeneous spatial VDs in simulating natural phenomena such as forest fire spread, and the algorithm's universality. However, the grid is difficult to recursively partition hierarchically, thus failing to meet the requirements for rapid local updates of spatial data and multi-scale spatial data analysis and related processing. Summary of the Invention

[0008] The technical problem to be solved: In satellite regional imaging, there are problems such as uneven grid granularity and long grid generation time when decomposing the observation area into map grids. To solve these problems, this invention proposes a hexagonal grid construction method for remote sensing satellite regional observation tasks. This map grid construction method is a global, large-scale, deformation-free, and non-overlapping spherical hexagonal map grid generation method. It can quickly construct and generate map grids for large-scale target areas by combining satellite orbit and payload-related constraints, and ensures uniform grid granularity. It is suitable for satellite regional imaging task coverage calculation, regional hotspot division, etc., and mainly serves satellite regional imaging tasks.

[0009] The technical solution of the present invention: A hexagonal grid construction method for remote sensing satellite regional observation missions, the process is as follows: Figure 4 As shown, The steps are as follows: (1) Construct a spherical hexagonal mesh model In GIS (Geographic Information System) applications, the Earth's surface is typically divided into equally spaced square grids according to latitude and longitude. Then, map projection transformations are used to tile these grids onto the Earth's surface, such as... Figure 5 As shown, the areas enclosed by these grids are not equal. For the grids near the North and South Poles, due to the curvature of the Earth, the area of ​​these grids is much smaller than that of the grids near the equator.

[0010] In designing the map grid subdivision model, this invention abandons the aforementioned subdivision model and instead adopts a method of directly covering the Earth's surface with a hexagonal grid. The configuration selected is a scheme with an aperture of 7 from the Discrete Global Grid Systems (DGGS) (usually classified into aperture schemes of aperture 3, aperture 4, and aperture 7). That is, a hexagon is uniformly and recursively subdivided into 7 sub-hexagons of equal side length, such as... Figure 6 As shown. This configuration is based on dividing the Earth into a spherical icosahedron, as... Figure 7 As shown, each face of the spherical icosahedron is a spherical triangle, uniformly covering the Earth's surface, totaling 20 faces.

[0011] This invention, based on the aforementioned spherical icosahedron, recursively divides each spherical triangular face into sub-hexagonal meshes according to the same rules. The initial hexagonal mesh level is defined as layer 0, and the initial hexagonal mesh side length is approximately 1000 kilometers. This results in a spherical hexagonal mesh subdivision model scheme with fewer subdivision levels and shorter generation time. Even at the finest granularity, i.e., when the average hexagonal mesh side length is approximately 1 meter, the subdivision level is only 14 layers, with parent-child unit levels as follows: Figure 8 As shown.

[0012] Due to the geometric properties of hexagons, when the Earth is divided into hexagonal grids, the surface cannot be completely covered, resulting in gaps and discontinuities in some areas. To ensure the dynamic continuity of the global grid, this invention introduces a fixed number of regular pentagons with the same side length as hexagons. That is, the number of regular pentagons remains constant at any level of division, always 12. This is because at each vertex of a spherical icosahedron, five spherical triangles intersect at that vertex. If each face is designed as a triangle at this vertex (with the same side length as a hexagon), a pentagon will be formed at the vertex. In other words, the triangles at the three vertices of each spherical triangle in the icosahedron are 1 / 5 the length of a pentagon, so each spherical triangle has 3 / 5 of a pentagon, resulting in 12 pentagons in the icosahedron. (See diagram below.) Figure 9 As shown.

[0013] In summary, the spherical hexagonal mesh partitioning model constructed in this invention consists of 110 hexagonal and 12 pentagonal meshes in the 0th layer (initial layer). The coordinates of the center points and vertices of these hexagons / pentagons are fixed (and serve as the calculation basis for subsequent layer partitioning), and the side lengths of the hexagonal and pentagonal meshes are equal. Starting from the 1st layer, since a mesh cell in a certain layer may belong to multiple mesh cells in the previous layer, this invention solves the problem of mesh layer attribution by treating the parent cell (upper layer) that generates the child cell (lower layer) differently. In this structure, one type is called the central parent cell, and the other is called the vertex parent cell, such as... Figure 10 As shown, the specific definition is: if the current unit (with) Figure 10 Taking the "central sub-unit" as an example, the center point of the sub-unit is related to a parent unit in the next higher level ( Figure 10 If the center points of the current unit (the "central parent unit") coincide, then that parent unit is called the central parent unit of the current unit, and the other 6 hexagons adjacent to the central parent unit are called vertex parent units; if ... Figure 10 Taking the "central parent unit" as an example, the center point of the parent unit and a child unit in the next level ( Figure 10If the center points of the "central sub-units" coincide, then the sub-unit is called the central sub-unit of the current unit, and the other 6 hexagons adjacent to the central sub-unit are called vertex sub-units.

[0014] For hexagonal / pentagonal meshes from layer 1 to other layers (the highest layer in this invention is 14), the mesh is partitioned according to the following principles: Taking a hexagonal mesh as an example (the pentagonal mesh is similar), only the mesh of the central parent unit can generate vertex child units, that is, the central parent unit can generate 1 central child unit and 6 vertex child units, while the mesh of the vertex parent unit can only generate 1 central child unit. In continuing the partitioning to the next layer, all central child units become central parent units, and all vertex child units become vertex parent units.

[0015] Taking a hexagonal mesh with 3 levels as an example, the mesh cell in level 0 (the initial mesh cell) is treated as the central parent cell. Following the above processing principle, in the second level, this cell can be divided into 7 sub-cells: 1 central cell and 6 vertex cells. The mesh cells in the second level are then further subdivided downwards. In the third level, the central cell in the second level is further subdivided into 7 sub-cells: 1 central cell and 6 vertex cells. The 6 vertex cells in the second level will generate 6 central cells. In the third level, there are a total of 13 mesh cells, with the innermost mesh cell being the central cell, the surrounding 6 cells being vertex cells, and the outermost 6 cells being central cells.

[0016] (2) Establish a spherical hexagonal grid spatial index Based on step (1), it is necessary to represent the spatial coordinates of each hexagonal / pentagonal grid in the hierarchy, that is, how to construct the spherical hexagonal grid spatial index (constructing the coding scheme). This invention adopts a self-developed coding scheme, which combines the expression method of XYZ coordinates of the geometric plane (the included angle between the XY, YZ, and ZX coordinate axes is 120 degrees, such as...). Figure 11 As shown in the diagram, to highlight the interrelationship between levels, each hexagonal / pentagonal mesh in this invention contains the XYZ coordinate values ​​of all hexagonal / pentagonal mesh cells in its parent levels (up to level 0). This way, only the construction of the sub-mesh of a single mesh needs to be considered, and the coordinates of all meshes can be obtained recursively (the coordinates of each mesh in the initial layer, i.e., level 0, are known). During encoding, the XYZ coordinate sequence of each hexagonal / pentagonal mesh is represented as follows: Figure 11As shown in the figure, the numbers 0 to 6 represent the sequence number of the cell when constructing or calculating the XYZ coordinates. Unlike the conventional understanding of numbering them one by one in clockwise or counterclockwise order, this is because the orientation of adjacent grid cells is rotated. In order to ensure the hierarchy of the address codes, the relative position of the grid address codes remains unchanged in odd / even layers, which facilitates fast calculation.

[0017] In this invention, the spatial coordinates (XYZ values) of the spherical hexagonal grid are represented in a computer using 16-bit hexadecimal values, occupying 64 bits. This can be represented by a 64-bit long integer type, with the structure shown below: Bits 1-4: Used as grid cell markers. All 0s indicate an invalid grid; 1 indicates a hexagonal grid; 2 indicates a pentagonal grid.

[0018] 5-8 bits: Represent the level number, with a value range of 0-7.

[0019] Bits 9-15: Indicates the index value of this grid belonging to the 0th layer grid, with a value range of 0-127.

[0020] 16-64 bits: Represents the XYZ coordinate values ​​of this grid. It consists of the XYZ coordinate values ​​of itself and all parent level units (up to level 0). For grids with a small number of levels, the empty bits are 0 to facilitate compression.

[0021] (3) Rapid generation of large-area grids In step (2), the above-mentioned spherical hexagonal mesh partitioning model and mesh spatial index construction were completed. Next, multi-scale, deformation-free, and non-overlapping spherical hexagonal meshes for global and large-scale target areas will be generated. The basic parameters need to be initialized according to different application methods. The coordinate information of the generated hexagonal mesh map will be stored in a vector format file for easy visualization and rendering by GIS graphics processing software. The details are as follows.

[0022] Global hexagonal grid map: Only the grid level k needs to be provided (the level and the hexagonal grid side length L have a fixed mapping relationship). The level determines the resolution of the map. The functional relationship between the number of hexagonal grids to be generated to construct the k-th layer map and the map level k is H(k), as shown in formula (1). Wherein, Hp is the number of pentagonal grids (fixed to 12 for any level), and n is the initial number of hexagonal grids. In this invention, n=110, so that the suitable subdivision level is less and the efficiency is higher. Because the value of n affects the initial hexagonal grid side length L value of the spherical hexagonal grid subdivision model, which in turn affects the subsequent deep recursive subdivision and ultimately determines the resolution of the map. (1) For a target region within a defined area: in addition to providing the grid level k, it is also necessary to specify the boundary point information (a set of closed intervals enclosed by latitude and longitude coordinates) P of the region. Then, the area enclosed by set P is... Equivalent calculations can be performed by considering the number of hexagonal meshes included. It equals the area of ​​a hexagon in level k multiplied by the total number of hexagons enclosed by set P, calculated as in formula (2): (2) in, Let P be the number of hexagonal grids enclosed by set P, k be the map level, and L be the side length of the hexagonal grids at level k. (Since the coordinates and side lengths of the level 0 cells are fixed and the maximum number of levels is determined, there is a fixed mapping relationship between the level and the hexagonal grid side length L. Therefore, when performing the k-th level subdivision, only the level k value needs to be specified as an external input parameter variable.) Generally, the area enclosed by set P is not directly calculated. Instead, it uses the number of hexagonal grids it contains. Substitute the values ​​into the formula for calculating the coverage area. For details, please refer to formula (3).

[0023] When constructing a hexagonal grid map of a ground area, determining whether a hexagonal grid cell is within the target area to be observed is the primary problem to be solved. Generally, there are five cases where hexagonal grid cells and closed regions are included in the detection, such as... Figure 12 As shown, the general approach is to detect the containment relationship between the center point of the hexagonal grid and the closed region. Many algorithms exist for determining whether a point is within a closed planar region; this paper uses the ray method. This involves drawing a ray from any point outside the closed region to the point to be determined, and then checking the parity of the number of intersections between the ray and the closed region. If the number is odd, the point is inside the polygon; otherwise, the point is outside. In summary, in cases (a), (d), and (e), the grid cells are displayed within the visible area of ​​the plane; in cases (b) and (c), the grid cells are removed from the visible area.

[0024] During satellite Earth observation operations, the strip area within the target region scanned by the satellite over a certain period can be determined by obtaining strip boundary information based on the swath width information constrained by the satellite orbit and payload. Then, the aforementioned calculations can be performed. The method for obtaining the number of hexagonal grids in the strip region of satellite scanning Therefore, the percentage of coverage area of ​​the target region observed by the satellite within a certain time window can be calculated. This can be done by equivalent conversion using the number of hexagonal grids. Thus, the percentage of coverage area... The calculation is shown in formula (3); where, This represents the number of hexagonal grids contained within a target area. The number of hexagonal grids contained in the target area scanned by the satellite; (3) Where k is the map level.

[0025] The present invention also provides a server, characterized in that it includes a memory and a processor, the memory storing a computer program configured to be executed by the processor, the computer program including instructions for performing the steps of the above-described method.

[0026] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the steps of the above-described method.

[0027] The beneficial effects of this invention are: This invention focuses on map grid construction in satellite regional imaging missions. It improves the efficiency of uniform grid granularity partitioning of ground target areas and calculation of effective satellite coverage areas based on existing satellite imaging constraints. Furthermore, the hexagonal grid map construction process ensures uniformity, continuity, no deformation, and no overlap, simplifying satellite regional imaging coverage calculations and thus improving the execution efficiency of satellite missions. In addition, the long integer address encoding scheme used in this invention is computationally faster than other grid map partitioning schemes because it does not require spatial data preprocessing, such as creating a dedicated index. This invention can consistently represent globally equal-area regions, enabling efficient storage and transmission. Simultaneously, since the hexagonal grid has the largest coverage area for the same side length, and the distance from the center of the hexagon to the center of adjacent cells is always equal, it provides faster and smoother visualization rendering effects. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the Geometry Clipmap spherical drawing for the global subdivision model of a regular icosahedron.

[0029] Figure 2 A schematic diagram of the algorithm for generating a hexagonal discrete grid system for a regular octahedron.

[0030] Figure 3 A schematic diagram illustrating the generation of Voronoi diagrams in heterogeneous spaces based on regular hexagonal lattice. (a) Heterogeneous VD map generated under constraints, (b) Heterogeneous VD map of the studied region.

[0031] Figure 4 This is a flowchart of a hexagonal grid construction method for remote sensing satellite regional observation missions.

[0032] Figure 5 This is a schematic diagram of an equally spaced latitude and longitude square grid.

[0033] Figure 6 This is a schematic diagram of a meshing scheme with an aperture of 7.

[0034] Figure 7 This is a schematic diagram of a spherical icosahedron.

[0035] Figure 8 This is a schematic diagram of the arrangement of parent and child units in a hexagonal grid.

[0036] Figure 9 This is a schematic diagram of the spherical triangular mesh partitioning.

[0037] Figure 10 This is a schematic diagram of a hexagonal mesh parent-child unit.

[0038] Figure 11 A schematic diagram showing the XYZ coordinate sequence.

[0039] Figure 12 This is a schematic diagram illustrating the detection relationship between grid cells and enclosed regions. (a) A hexagonal mesh is closed within the region, (b) A hexagonal mesh is closed outside the region, (c) A hexagonal mesh intersects with the closed region but its center point is outside the closed region, (d) A hexagonal mesh intersects with the closed region but its center point is inside the closed region, (e) A hexagonal mesh intersects with the closed region but its center point is inside one of the vertices of the closed region.

[0040] Figure 13 Flowchart for generating center point data for a spherical hexagonal grid map.

[0041] Figure 14 The process for creating spatial coordinate indexes for spherical hexagonal grids and generating grid vector data.

[0042] Figure 15 The visualization rendering process for a hexagonal grid map of a certain area in the 7th layer. Detailed Implementation

[0043] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0044] In the specific implementation of this invention, taking a certain region in China as the observation area for a satellite imaging mission as an example, the map grid construction method of this invention is used to generate a map grid for the observation area. During implementation, a graphics workstation equipped with an Intel Xeon processor is used for real-time grid map construction. When constructing the hexagonal grid map in real time, the workstation employs multi-threaded parallel processing technology to recursively calculate the hexagonal grid map data in real time, and uses open-source GIS graphics processing software to visualize and render the generated grid map.

[0045] The first step is to set the basic parameters of the grid map. In this experiment, the grid map is set to level 7, corresponding to a side length L≈1km for the hexagonal / pentagonal grid. The observation area is selected as a region (the latitude and longitude coordinates can be obtained from the vector map file or by clicking on the map with the mouse), with an area approximately 34,000 square kilometers. The multi-level grid map constructed in this experiment is used for mission coverage calculations by Earth observation satellites. The map resolution should be adapted to the resolution required by the satellite payload; this experiment uses the highest level 7 map resolution. For example... Figure 13 The diagram shows the process for generating center point data for a spherical hexagonal grid map.

[0046] The second step, according to the invention content, is to generate a total of approximately 98 million spherical hexagonal / pentagonal grids covering the entire globe in the 7th layer. Then, according to the invention content (3) Figure 12 The target area clipping rules listed result in approximately 7000 hexagonal / pentagonal grid maps for a given area. Furthermore, the vertex data of the hexagonal / pentagonal grid maps generated by this invention all use a proprietary 64-bit long integer encoding format (see invention content (2) for details). To facilitate the display of the grid maps in GIS graphics processing software, it is necessary to establish hexagonal grid address codes and latitude / longitude coordinate conversion rules, as follows: The conversion of hexagonal / pentagonal grid address codes to latitude and longitude coordinates begins by establishing grid coordinate codes relative to the center of the previous grid layer, starting from the current level (level 7 in this implementation). The relative offset of the coordinate point in each level is recursively calculated upwards using the grid address codes. Finally, all offsets are added together to obtain the absolute offset, i.e., the point's position in the initial grid (level 0). Then, using the known initial grid (level 0) coordinates and inverse Schneider projection transformation, the latitude and longitude coordinates of each hexagonal / pentagonal grid vertex in level 7 are calculated. The conversion of latitude and longitude coordinates to hexagonal / pentagonal grid address codes first uses Schneider projection transformation to convert latitude and longitude into Cartesian coordinates on a plane. Then, based on the maximum subdivision level (level 7 in this implementation), the distance and azimuth from the coordinate point to the coordinate center are calculated recursively, starting from the initial grid (level 0), to determine the address code of the hexagonal grid. For example... Figure 14The diagram shows the process of creating a spherical hexagonal / pentagonal grid spatial coordinate index and generating grid vector data.

[0047] The third step involves writing the spatial coordinates (latitude and longitude) of the spherical hexagonal / pentagonal grid generated in the second step into a file according to a specific map file format. Then, GIS graphics processing software is used to display the grid map. At this point, the construction of a uniform, continuous, distortion-free, and non-overlapping grid map is complete. Figure 15 The image shows the visualization rendering process of a hexagonal / pentagonal grid map of a certain area in the 7th layer.

[0048] Although specific embodiments of the invention have been disclosed for illustrative purposes to aid in understanding and implementing the invention, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the invention should not be limited to the content disclosed in the preferred embodiments, and the scope of protection claimed by the invention is defined by the claims.

Claims

1. A hexagonal grid construction method for remote sensing satellite regional observation missions, comprising the following steps: 1) Constructing a spherical hexagonal mesh partitioning model: A spherical hexagonal map mesh partitioning model based on digital earth is constructed. The map mesh partitioning model selects a scheme with an aperture of 7 in the discrete global grid system. The 0th layer of the spherical hexagonal map mesh partitioning model is constructed through n hexagons and H. p The Earth's surface is divided into pentagonal grid cells to obtain the 0th layer digital grid map of the digital Earth. The center point coordinates and vertex coordinates of each hexagonal and pentagonal grid are fixed, and the side lengths of the hexagonal and pentagonal grids are equal. Then, according to the set rules, the center point coordinates and vertex coordinates of each hexagonal and pentagonal grid in each layer of the digital grid map from the first layer to the set highest layer of the spherical hexagonal grid subdivision model are calculated as the digital grid map of the corresponding layer of the digital Earth. The setting rules are as follows: Each grid in the k-th layer digital grid map is used as a central parent unit. Each central parent unit in the k-th layer digital grid map generates one central child unit and multiple vertex child units in the (k+1)-th layer digital grid map. If the central child unit is a pentagon, five corresponding vertex child units are generated; if the central child unit is a hexagon, six corresponding vertex child units are generated. The center position of the central parent unit in the k-th layer digital grid map coincides with the center position of its generated central child unit. The center point position of the adjacent unit of the central parent unit in the k-th layer digital grid map coincides with the center position of one of its generated vertex child units. Then, each central child unit in the (k+1)-th layer digital grid map is used as a central parent unit to generate the grid in the (k+2)-th layer digital grid map. The pentagonal grids in each layer of the digital grid map are all H... p indivual; 2) Establish a spherical hexagonal grid spatial index: Establish an index for each digital grid map cell in each layer; based on the center point coordinates and vertex coordinates of each grid in layer 0, and the parent-child hierarchical relationship between adjacent layers, recursively calculate the coordinates of each grid cell in the k-th layer digital grid map; based on the coordinates of each grid cell in the k-th layer digital grid map and the coordinates of its parent grid cell, generate the coded value of the corresponding grid cell in the k-th layer digital grid map as the grid index value; 3) Rapid generation of large-scale regional grids: Generate a global hexagonal grid map based on the constructed spherical hexagonal grid subdivision model, or retrieve the spherical hexagonal grid subdivision model based on the coordinates of the target area, and generate a hexagonal grid map of the target area according to the retrieval results; then store the coordinate information of the generated hexagonal grid map in a file with a set vector format for visualization rendering using GIS graphics processing software.

2. The method according to claim 1, characterized in that, The functional relationship between the number of hexagonal grids H(k) to be generated for the k-th layer digital grid map of the spherical icosahedron spherical hexagonal mesh partitioning model described in step 1) and the map layer k is as follows:

3. The method according to claim 1 or 2, characterized in that, n=110,H p =12。 4. The method according to claim 1 or 2, characterized in that, The encoded value mentioned in step 2) is represented in the computer using a 64-bit long integer type. Its structure is as follows: bits 1-4 are grid cell markers, bits 5-8 represent the grid level number, bits 9-15 represent the grid number of the 0th level, and bits 16-64 represent the XYZ coordinates of this grid, including its own and the XYZ coordinates of all parent level cells.

5. The method according to claim 1, characterized in that, The results of the rapid generation of the large-area mesh described in step 3) are stored in a file with a specific vector format.

6. A server, characterized in that, It includes a memory and a processor, the memory storing a computer program configured to be executed by the processor, the computer program including instructions for performing each step of the method of any one of claims 1 to 5.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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