Dem data loading method and system for drone flight area and storage medium

Abstract

The application provides a method and system for loading DEM data of a flight area of a UAV and a storage medium. The method comprises the following steps: slicing global DEM data according to a preset size of a latitude-longitude grid to generate a plurality of tiles and independently saving the tiles as tif files in a disk; obtaining a flight area of the UAV, and expanding the flight area to obtain a rectangular target area; finding tiles with an overlapping area in global tiles according to the target area, and loading corresponding tif files from the disk into a memory; splicing the loaded tif files to obtain target area DEM data; and cutting the target area DEM data according to the flight area to obtain flight area DEM data. The DEM data slicing storage strategy, spatial indexing mechanism and minimum data transmission mechanism of the application reduce DEM data transmission redundancy, significantly improve the loading efficiency of DEM data, and the overall architecture is lightweight, which is suitable for embedded platforms of the UAV.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of digital elevation model data processing, in particular to a DEM data loading method and system for a flight area of an unmanned aerial vehicle and a storage medium. BACKGROUND

[0002] With the development of automatic flight, terrain following flight, low-altitude simulation and obstacle avoidance technology of unmanned aerial vehicles, higher requirements are put forward for real-time acquisition, management and loading efficiency of terrain data (DEM, digital elevation model) in the flight task area.

[0003] The traditional method generally uses PostgreSQL + PostGIS to store DEM raster data and relies on spatial indexes (such as GiST, R-Tree) for querying. Although this method has spatial query capability, it relies on a complex GIS tool chain, and the system deployment and maintenance are complex. In addition, the spatial index method has high technical complexity and resource consumption in the scene of small-area flight area or light use, causing waste of bandwidth and memory, and is especially not suitable for embedded platforms or light task systems. SUMMARY

[0004] In order to solve the above technical problems, the application provides a DEM data loading method and system for a flight area of an unmanned aerial vehicle and a storage medium.

[0005] According to a first aspect of the application, a DEM data loading method for a flight area of an unmanned aerial vehicle is provided, comprising:

[0006] Slicing global DEM data according to a preset size of a latitude and longitude grid to generate a plurality of tiles and independently saving the tiles as tif files in a disk;

[0007] Obtaining a flight area of the unmanned aerial vehicle, and expanding the flight area to obtain a rectangular target area;

[0008] According to the target area, finding tiles with overlapping areas in the global tiles, and loading corresponding tif files from the disk into memory;

[0009] Splicing the loaded tif files to obtain target area DEM data;

[0010] According to the flight area, cutting the target area DEM data to obtain flight area DEM data.

[0011] Preferably, the method further comprises:

[0012] constructing a tile index table for finding tiles with overlapping regions and their corresponding tif file names according to the boundary information of the input spatial object;

[0013] finding tiles with overlapping regions in the global tiles according to the target region and loading the corresponding tif file from the memory, comprising:

[0014] finding tiles with overlapping regions in the global tiles and their corresponding tif file names according to the target region through the tile index table, and loading the corresponding tif file from the disk.

[0015] Preferably, the tile index table is constructed for finding tiles with overlapping regions and their corresponding tif file names according to the boundary information of the input spatial object, comprising:

[0016] The tile index table is constructed based on a relational database, and the tile index table is used to find tiles with overlapping regions through spatial indexing according to the boundary information of the input spatial object, and find the tif file name corresponding to the tile;

[0017] finding tiles with overlapping regions in the global tiles according to the target region and loading the corresponding tif file from the disk, comprising:

[0018] finding tiles with overlapping regions in the global tiles according to the boundary information of the target region through the spatial indexing of the tile index table, finding the tif file name corresponding to the tile, and then loading the corresponding tif file from the disk.

[0019] Preferably, the tile index table is constructed based on a MySQL database, and the structure of the tile index table comprises:

[0020] primary key, tif file name, minimum latitude of tile coverage area, maximum latitude of tile coverage area, minimum longitude of tile coverage area, maximum longitude of tile coverage area, and tile boundary information;

[0021] The tif file name is stored through the filename field and file retrieval is performed through the field. A spatial index is created on the geometry field for storing tile boundary information to support fast query based on spatial relationship.

[0022] Preferably, the flight area of the unmanned aerial vehicle is obtained, and a rectangular target region is obtained by expanding the flight area, comprising:

[0023] The flight area of the unmanned aerial vehicle is obtained, and the minimum longitude, minimum latitude, maximum longitude and maximum latitude covered by the flight area are determined;

[0024] Determining a first boundary point based on the minimum longitude and minimum latitude covered by the flight area, and determining a second boundary point based on the maximum longitude and maximum latitude covered by the flight area;

[0025] A minimum rectangular target area is determined based on the first boundary points and the second boundary points.

[0026] Preferably, the step of splicing the loaded tif files to obtain the DEM data of the target area includes:

[0027] When searching for a tile through the tile index table, the minimum latitude, maximum latitude, minimum longitude and maximum longitude of the tile coverage area are recorded simultaneously;

[0028] According to the recorded longitude and latitude information, the loaded tif files are spliced ​​in the preset order to obtain the DEM data of the target area.

[0029] Preferably, the step of splicing the loaded tif files to obtain the DEM data of the target area includes:

[0030] The tif file name of each tile is named in the format of the latitude and longitude information of the area it covers;

[0031] When loading a tif file, read the file's internal metadata to obtain the latitude and longitude information;

[0032] The loaded tif files are spliced ​​in a preset order according to the latitude and longitude information to obtain the DEM data of the target area.

[0033] According to the second aspect of the present application, a DEM data loading system for a UAV flight area is proposed, comprising:

[0034] Slicing unit, configured to slice the global DEM data according to the pre-set latitude and longitude grid, generate multiple tiles and save them independently as tif files to disk;

[0035] an expansion unit configured to obtain a flight area of ​​the UAV and expand the flight area to obtain a rectangular target area;

[0036] A loading unit configured to find tiles with overlapping areas in the global tiles according to the target area, and load the corresponding tif files from the disk into the memory;

[0037] The splicing unit is configured to splice the loaded tif files to obtain the DEM data of the target area;

[0038] The clipping unit is configured to clip the target area DEM data according to the flight area to obtain the flight area DEM data.

[0039] According to a third aspect of the present application, an electronic device is provided, comprising: one or more processors; a memory for storing one or more programs, which when executed by the one or more processors, cause the electronic device to implement the DEM data loading method of a UAV flight area as provided in any of the embodiments of the first aspect above.

[0040] According to a fourth aspect of the present application, a computer readable storage medium is provided, which stores a computer program, which when executed by a processor, implements the DEM data loading method of a UAV flight area as provided in any of the embodiments of the first aspect above.

[0041] The present application provides a DEM data loading method, system and storage medium of a UAV flight area, which slices global DEM data based on a small range of latitude and longitude grid and saves it in a tif file in a disk, without relying on a spatial database, and supports caching, distribution and incremental updating of DEM data, which can significantly improve data processing efficiency. A tile index table is constructed using a common relational database, the target area of the minimum rectangle is obtained by expanding the flight area, the tile index table can quickly locate the tile with overlapping area with the target area, only the necessary tif file in the disk is loaded into the memory, and finally the flight area DEM data is obtained by file splicing and cutting. The spatial indexing mechanism and the minimum data transmission mechanism of the present application reduce the DEM data transmission redundancy, significantly improve the loading efficiency of the DEM data, and the overall architecture is lightweight, which is suitable for embedded platform of UAV. BRIEF DESCRIPTION OF DRAWINGS

[0042] The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the application. Other embodiments and many of the intended advantages of the present application will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

[0043] Figure 1 is a DEM data loading method flowchart of a UAV flight area according to an embodiment of the present application;

[0044] Figure 2 is a field structure diagram of a tile index table according to an embodiment of the present application;

[0045] Figure 3 is an index diagram of a tile index table according to an embodiment of the present application;

[0046] Figure 4 is a DEM data loading service logic diagram of a UAV flight area according to one specific embodiment of the present application;

[0047] Figure 5 is a schematic diagram of a DEM data loading system of a UAV flight area according to one embodiment of the present application;

[0048] Figure 6 is a schematic diagram of an electronic device according to one specific embodiment of the present application. DETAILED DESCRIPTION

[0049] The features and exemplary embodiments of various aspects of the present application will be described below in detail, in order to make the purposes, technical solutions and advantages of the present application more clear and apparent, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present application, and are not configured to limit the present application. The present application can be implemented without some of these specific details by those skilled in the art. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application.

[0050] It should be noted that, in this paper, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the elements defined by the statement "include" do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0051] The present application proposes a DEM data loading method for a UAV flight area. Figure 1 A DEM data loading method flow chart for a UAV flight area according to one specific embodiment of the present application is shown, as shown in Figure 1 The method comprises the following steps:

[0052] Step S101: Slice the global DEM data according to the preset size of the latitude and longitude grid to generate a plurality of tiles and save them as tif files independently to the disk.

[0053] In a specific embodiment, the global DEM data is divided into a fixed grid of 0.2°×0.2° longitude and latitude, and a small tile is cut out of each grid and saved as an independent tif file in a folder on the disk, named N25E141_141.6_25.0.tif. In this way, DEM data storage does not need to rely on a spatial database and supports multi-version management, incremental updates and caching.

[0054] It's important to note that tile sizes can be customized based on actual needs. Larger tiles increase data transmission redundancy, but tiles within the same latitude and longitude range occupy less disk space. Smaller tiles decrease data transmission redundancy, but tiles within the same latitude and longitude range occupy more disk space. This is because each individual file contains metadata, and the amount of space occupied by metadata for each file is roughly the same.

[0055] Step S102: constructing a tile index table, which is used to find tiles with overlapping areas and their corresponding tif file names according to the boundary information of the input spatial objects.

[0056] In a specific embodiment, a tile index table is constructed based on a relational database. The tile index table is used to find tiles with overlapping areas in global tiles through spatial indexes according to boundary information of input spatial objects, and to find the tif file name corresponding to the tile.

[0057] In a specific embodiment, a tile index table is constructed based on a MySQL database. The tile index table construction statement is as follows:

[0058] CREATE TABLE flight_dem_tile_info (

[0059] id INT AUTO_INCREMENT PRIMARY KEY COMMENT 'primary key id',

[0060] filename VARCHAR(255) NOT NULL COMMENT 'TIF file name',

[0061] min_lat DOUBLE NOT NULL COMMENT 'The minimum latitude of the tile coverage area (south boundary)',

[0062] max_lat DOUBLE NOT NULL COMMENT 'The maximum latitude (northern boundary) of the tile coverage area',

[0063] min_lon DOUBLE NOT NULL COMMENT 'The minimum longitude (west boundary) of the tile coverage area',

[0064] max_lon DOUBLE NOT NULL COMMENT 'The maximum longitude (eastern boundary) of the tile coverage area',

[0065] tile_bounds GEOMETRY NOT NULL COMMENT 'Tile boundary information (spatial geometry object)',

[0066] SPATIAL INDEX sp_index_tile_bounds (tile_bounds)

[0067] ) ENGINE = InnoDB;

[0068] Figure 2 FIG. 1 shows a field structure diagram of a tile index table according to a specific embodiment of the present application. Figure 2 As shown in the figure, the tile index table structure includes: primary key, tif file name, minimum latitude of the tile coverage area, maximum latitude of the tile coverage area, minimum longitude of the tile coverage area, maximum longitude of the tile coverage area and tile boundary information. Among them, the tif file name is stored in the filename field and file retrieval is performed through this field; a spatial index sp_index_tile_bounds is created on the geometry field tile_bounds that stores tile boundary information to support fast queries based on spatial relationships.

[0069] Figure 3 FIG. 4 shows an index diagram of a tile index table according to a specific embodiment of the present application. Figure 3 As shown, by inputting the boundary information of the spatial object, the tile index table can quickly find tiles with overlapping areas and find the corresponding tif file names, and then quickly find the corresponding tif files on the disk.

[0070] Step S103: Acquire the flight area of ​​the UAV, and expand the flight area to obtain a rectangular target area.

[0071] In one specific embodiment, the UAV ground station determines the minimum longitude, minimum latitude, maximum longitude and maximum latitude of the flight area covered by the flight route data (i.e. the boundary values of the flight area in the east-west-north-south four directions), then determines a first boundary point according to the minimum longitude and the minimum latitude of the flight area covered, determines a second boundary point according to the maximum longitude and the maximum latitude of the flight area covered, and expands the first boundary point and the second boundary point to obtain a target area of a minimum rectangle. Finally, the ground station sends the boundary information of the target area to the backend server.

[0072] Step S104: According to the target area, find the tiles with overlapping areas in the global tiles, and load the corresponding tif files from the disk into the memory.

[0073] In one specific embodiment, the backend server finds the tiles with overlapping areas in the global tiles according to the boundary information of the target area through the sp_index_tile_bounds spatial index of the tile index table, and finds the tif file name corresponding to the tile through the filename field of the tile index table, and then loads the corresponding tif file from the tile folder on the disk into the memory.

[0074] It should be noted that the conventional DEM data loading method generally uses PostgreSQL + PostGIS to store DEM data, which can handle complex spatial objects and large amounts of data, but the overall storage is bloated and depends on a spatial database, and the deployment is complex and the running resources are consumed, which is difficult to use in resource-limited devices, and is not suitable for embedded platforms or lightweight task systems.

[0075] The present application tiles and slices the DEM data and saves it in the form of files in the folder on the disk, and the DEM data storage method is more concise and does not depend on a spatial database. By expanding the complex flight area of the UAV into a simple rectangular target area, only simple rectangular spatial objects need to be processed during spatial indexing, so the spatial index of the ordinary relational database MySQL can still perform well when processing simple objects, and the loading efficiency of the DEM data can be significantly improved in a simple scenario, and the overall system is more lightweight.

[0076] Step S105: Splice the loaded tif files to obtain the target area DEM data.

[0077] Specifically, spatial indexing through the tile index table may hit multiple tiles, and after the backend server loads the tif files from the tile folder on the disk, it needs to be spliced in order to obtain complete target area DEM data.

[0078] In one specific embodiment, the splicing process is as follows: when a tile is found by searching the tile index table, the minimum latitude, maximum latitude, minimum longitude and maximum longitude of the tile coverage area are recorded at the same time; according to the recorded longitude and latitude information, the loaded tif file is spliced according to the preset order of longitude and latitude, and the target area DEM data is obtained.

[0079] In another specific embodiment, the splicing process is as follows: the tif file name of each tile is named in the format of the longitude and latitude information (minimum latitude, maximum latitude, minimum longitude, maximum longitude) of its coverage area to improve program readability; the longitude and latitude information is obtained by reading the internal metadata of the file when the tif file is loaded; according to the longitude and latitude information, the loaded tif file is spliced according to the preset order of longitude and latitude, and the target area DEM data is obtained.

[0080] Step S106: According to the flight area, the target area DEM data is cut to obtain the flight area DEM data.

[0081] Specifically, after the backend server loads the spliced target area DEM data, the target area DEM data is cut according to the actual size of the flight area to obtain the flight area DEM data, and then the flight area DEM data is returned to the ground station, and the ground station transmits the flight area DEM data to the flight control through the TERRAIN_DATA message of the MAVLink protocol to execute the unmanned aerial vehicle flight task.

[0082] Figure 4 The DEM data loading business logic diagram of the flight area of the unmanned aerial vehicle according to one specific embodiment of the application is shown in FIG. 1. Figure 4 As shown in FIG. 1, the overall business logic is as follows:

[0083] 1) The ground station expands the flight area of the unmanned aerial vehicle to obtain a target area;

[0084] 2) The ground station sends the boundary information (longitude and latitude range) of the target area to the backend server;

[0085] 3) The backend server queries the tiles that have overlapping areas with the target area in the global tiles through the MySQL tile index table;

[0086] 4) The MySQL tile index table returns the list of hit tile files to the backend server;

[0087] 5) The backend server loads the corresponding tif file into the memory from the tile folder on the disk;

[0088] 6) The backend server obtains the final flight area DEM data through DEM data splicing and cutting;

[0089] 7) The backend server returns the flight area DEM data to the ground station;

[0090] 8) The ground station transmits the flight area DEM data to the flight control through sending TERRAIN_DATA message of MAVLink protocol.

[0091] In summary, the DEM data loading method for the flight area of the unmanned aerial vehicle provided in the present application slices the global range DEM data based on a small range latitude and longitude grid, and saves the DEM data in tif files in the disk. The DEM data storage is more concise, does not need to rely on a spatial database, and supports the caching, distribution and incremental updating of the DEM data, and can significantly improve the data processing efficiency. A tile index table is constructed using a common relational database MySQL, the target area of the minimum rectangle is obtained according to the flight area expansion, the tile index table of the MySQL can quickly query the tiles that exist in the overlapping area with the target area in the global tile, only the necessary tif files in the disk are loaded into the memory, and finally the flight area DEM data is obtained through file splicing and cutting. The DEM data tiling slicing storage strategy, spatial index mechanism and minimum data transmission mechanism of the present application reduce the DEM data transmission redundancy, significantly improve the DEM data loading efficiency, and the overall architecture is lightweight, which is suitable for the embedded platform of the unmanned aerial vehicle.

[0092] According to the DEM data loading method for the flight area of the unmanned aerial vehicle, based on the same inventive concept, the present application further provides a DEM data loading system for the flight area of the unmanned aerial vehicle, Figure 5 A schematic diagram of the DEM data loading system for the flight area of the unmanned aerial vehicle according to an embodiment of the present application is shown, as Figure 5 shown, the system comprises:

[0093] The slicing unit 201 is configured to slice the global range DEM data according to the preset size of the latitude and longitude grid, generate a plurality of tiles and independently save the tiles as tif files in the disk.

[0094] The index unit 202 is configured to construct a tile index table, and the tile index table is used to find the tiles and their corresponding tif file names that exist in the overlapping area according to the boundary information of the input spatial object.

[0095] The expansion unit 203 is configured to obtain the flight area of the unmanned aerial vehicle, and expand the target area of the rectangle according to the flight area.

[0096] The loading unit 204 is configured to find the tiles that exist in the overlapping area in the global tile according to the target area, and load the corresponding tif files in the disk into the memory.

[0097] The splicing unit 205 is configured to splice the loaded tif file to obtain the target area DEM data.

[0098] The cropping unit 206 is configured to crop the target area DEM data according to the flight area to obtain the flight area DEM data.

[0099] According to the DEM data loading method for the flight area of the unmanned aerial vehicle, based on the same inventive concept, the present application further provides an electronic device. Figure 6 A schematic diagram of an electronic device according to an embodiment of the present application is shown as follows. Figure 6 As shown in the figure, the electronic device comprises:

[0100] one or more processors 301, a memory 302, a bus 303 and a communication interface 304. Among them, the one or more processors 301, the memory 302 and the communication interface 304 are connected through the bus 303. The memory 302 is used to store one or more programs, when the one or more programs are executed by the one or more processors 301, the electronic device realizes the DEM data loading method for the flight area of the unmanned aerial vehicle provided by any one of the above embodiments.

[0101] According to the DEM data loading method for the flight area of the unmanned aerial vehicle, based on the same inventive concept, the present application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the DEM data loading method for the flight area of the unmanned aerial vehicle provided by any one of the above embodiments.

[0102] In the embodiments of the present application, it should be understood that the disclosed technical contents can be implemented by other ways. Among them, the above described device / system / method embodiment is only schematic, for example, the division of the unit can be a logical function division, and actual implementation can have another division way, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the coupling or direct coupling or communication connection between the displayed or discussed each other can be through some interface, indirect coupling or communication connection between units or modules, which can be electrical or other forms.

[0103] The unit described as a separate component can or can not be physically separated, and the component shown as a unit can or can not be a physical unit, that is, it can be located in one place, or it can be distributed to multiple units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0104] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software function unit.

[0105] When the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0106] Obviously, those skilled in the art can make various modifications and changes to the embodiments of the present application without departing from the spirit and scope of the present application. In this way, if these modifications and changes are within the scope of the claims of the present application and their equivalents, the present application also intends to cover these modifications and changes. The word "comprises" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are described in mutually different dependent claims does not mean that the combination of these measures cannot be used to advantage. Any reference signs in the claims should not be considered as limiting the scope.

Claims

1. A method for loading DEM data of a UAV flight area, characterized by: include: Slice the global DEM data according to the preset latitude and longitude grid, generate multiple tiles and save them independently as tif files to disk; Construct a tile index table, which stores the boundary information of each tile. The tile index table is used to find tiles with overlapping areas and their corresponding tif file names according to the boundary information of the input spatial geometric objects; Obtaining the flight area of ​​the UAV, and expanding the flight area to obtain a rectangular target area; According to the boundary information of the target area, find the tiles with overlapping areas and their corresponding tif file names in the global tiles through the tile index table, and load the corresponding tif files from the disk; Splice the loaded tif files to obtain the DEM data of the target area; According to the flight area, the DEM data of the target area is clipped to obtain the DEM data of the flight area; The tile index table is constructed based on the MySQL database, and the tile index table structure includes: Primary key, tif file name, minimum latitude of tile coverage area, maximum latitude of tile coverage area, minimum longitude of tile coverage area, maximum longitude of tile coverage area and tile boundary information; The filename field is used to store the tif file name and to retrieve the file. A spatial index is created on the geometry field that stores tile boundary information to support fast queries based on spatial relationships. The loaded tif files are spliced ​​to obtain the DEM data of the target area, including: The tif file name of each tile is named in the format of the latitude and longitude information of the area it covers; When loading a tif file, read the file's internal metadata to obtain the latitude and longitude information; The loaded tif files are spliced ​​in a preset order according to the latitude and longitude information to obtain the DEM data of the target area.

2. The method according to claim 1, characterized in that The obtaining of the flight area of ​​the UAV and the expansion of the rectangular target area according to the flight area include: Obtaining a flight area of ​​the UAV, and determining the minimum longitude, minimum latitude, maximum longitude, and maximum latitude covered by the flight area; Determining a first boundary point based on the minimum longitude and minimum latitude covered by the flight area, and determining a second boundary point based on the maximum longitude and maximum latitude covered by the flight area; A minimum rectangular target area is determined based on the first boundary points and the second boundary points.

3. A DEM data loading system for UAV flight areas, characterized by: include: Slicing unit, configured to slice the global DEM data according to the pre-set latitude and longitude grid, generate multiple tiles and save them independently as tif files to disk; An indexing unit is configured to construct a tile index table, wherein the tile index table stores boundary information of each tile, and is used to find tiles with overlapping areas and their corresponding tif file names based on the boundary information of the input spatial geometric objects. The tile index table is constructed based on a MySQL database, and the tile index table structure includes: a primary key, a tif file name, the minimum latitude of the tile coverage area, the maximum latitude of the tile coverage area, the minimum longitude of the tile coverage area, the maximum longitude of the tile coverage area, and tile boundary information; the tif file name is stored in a filename field and file retrieval is performed through this field; a spatial index is created on the geometry field storing the tile boundary information to support fast queries based on spatial relationships; an expansion unit configured to obtain a flight area of ​​the UAV and expand the flight area to obtain a rectangular target area; A loading unit configured to find tiles with overlapping areas and their corresponding tif file names in the global tiles according to the boundary information of the target area through the tile index table, and load the corresponding tif files from the disk; The splicing unit is configured to splice the loaded tif files to obtain the DEM data of the target area, including: naming the tif file name of each tile in the format of the latitude and longitude information of the area it covers; reading the internal metadata of the file to obtain the latitude and longitude information when loading the tif file; splicing the loaded tif files in a preset order according to the latitude and longitude information to obtain the DEM data of the target area; The clipping unit is configured to clip the target area DEM data according to the flight area to obtain the flight area DEM data.

4. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs, which, when executed by the one or more processors, enables the electronic device to implement the method according to any one of claims 1 to 2.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 2 is implemented.

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