Water-land integrated all-terrain DEM surveying method and system based on UAV-USV-GIS

Abstract

The invention discloses a water-land integrated all-terrain DEM surveying method and system based on UAV-USV-GIS, and belongs to the field of terrain surveying. The method comprises the steps of determining a research area range, planning an unmanned aerial vehicle route, and laying image control points; performing aerial survey on the planned route by using an unmanned aerial vehicle to obtain ground point cloud data and images, and respectively processing the ground point cloud data and images into a land DEM and an orthoimage; the boundaries of the subsidence water area are extracted through the orthoimages, the measurement route of the unmanned ship is planned, and underwater topographic data are measured; processing the underwater topographic data, generating a water area DEM, uniformly selecting inspection points by using RTK and sounding equipment to carry out sampling measurement on the underwater elevation, and verifying the accuracy of the water area DEM underwater topographic data; and fusing the land DEM and the water area DEM to generate a complete water-land integrated all-terrain DEM. The technical bottlenecks that the efficiency is low, the data at the junction of water and land is not accurate, and only the elevation data of a single area of the land or the water can be obtained in the subsidence water area terrain modeling by a traditional single measurement means are effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of terrain surveying, and in particular relates to a UAV-USV-GIS-based water-land integrated all-terrain DEM survey method and system. Background Art

[0002] Large-scale coal mining is causing surface subsidence. In mining areas with high groundwater levels, the intersection of the groundwater level and the elevation of the bottom of the subsidence basin can easily lead to the formation of large areas of subsidence. These areas, characterized by irregular boundaries, destructive topography, and dynamic water level fluctuations, not only threaten the ecological environment of mining areas but also pose severe challenges to land reclamation, disaster assessment, and engineering management. High-precision, full-terrain elevation data is urgently needed to support scientific decision-making.

[0003] Unmanned aerial vehicle (UAV) technology has become an important means of monitoring surface deformation due to its flexible maneuverability and high-resolution data acquisition capabilities. By equipping it with a laser radar (Light Detection And Ranging, LiDAR) and a high-definition camera, it can quickly acquire surface point cloud data and orthophotos, enabling subsidence range extraction, surface elevation modeling, and vegetation cover analysis. Its monitoring accuracy can reach the centimeter level, significantly superior to traditional manual measurement methods. Unmanned surface vessels (USVs) are equipped with sonar depth sounding systems and high-precision positioning equipment, which can efficiently detect the underwater topography of subsidence waters. Compared with traditional ship measurements, unmanned vessels have the advantages of strong shallow water operation capabilities, flexible obstacle avoidance, and a high degree of data collection automation. They can obtain high-density underwater point cloud data, providing key data support for the depth distribution of subsidence waters, reservoir capacity calculation, and inundation prediction.

[0004] Currently, monitoring of subsidence waters mostly uses independent operation modes of drones and unmanned boats, which have the following problems: drones cannot obtain underwater terrain data, and unmanned boats have difficulty covering the water-land transition zone; manual planning of survey lines is inefficient and cannot dynamically avoid surface obstacles; and water level fluctuations cause inconsistent water and land elevation benchmarks. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a UAV-USV-GIS-based water-land integrated all-terrain DEM survey method and system to solve the problems in the prior art.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A UAV-USV-GIS-based integrated land-water all-terrain DEM survey method includes the following steps:

[0008] Determine the scope of the study area, plan the drone route, and deploy image control points;

[0009] According to the planned drone route, use drones to conduct aerial surveys, obtain ground point cloud data and images, and process them into land DEM and orthophoto images respectively;

[0010] Extract the boundary of the submerged water area, use the orthophoto to determine the scope of the submerged water area, and plan the measurement route of the unmanned vessel in combination with the actual terrain to measure underwater terrain data;

[0011] Process underwater terrain data to generate a water area DEM. Use RTK and bathymetric equipment to evenly select checkpoints for sampling measurements of bottom elevation to verify the accuracy of underwater terrain data in the water area DEM.

[0012] The land DEM and water DEM are merged to generate a complete land-water integrated full-terrain DEM.

[0013] Furthermore, the drone is equipped with a lidar and a camera to acquire ground point cloud data and images, respectively;

[0014] The ground point cloud data is processed through static data processing, POS solution, flight strip clipping, point cloud filtering, and elevation accuracy verification to finally generate a land DEM;

[0015] The image is first homogenized, and then image control points and aerial triangulation operations are performed to obtain an orthophoto.

[0016] Furthermore, the process of extracting the boundary of the subsidence water area is as follows: using multi-scale image segmentation, calculating the difference vegetation index, the difference water index between the standard deviation and the average value of the blue band, and extracting the boundary of the subsidence water area through threshold segmentation.

[0017] Furthermore, underwater terrain data processing includes: after smoothing and filtering to eliminate errors, the underwater terrain data directly measured by the unmanned vessel is extracted with a point spacing of 5m to obtain plane coordinates, water surface elevation, water depth and bottom elevation values.

[0018] Furthermore, the steps of merging land DEM and water DEM include:

[0019] S51, unify the coordinate system and elevation datum of land DEM and water DEM

[0020] S52 establishes a buffer zone at the junction of the water area and the land area, and uses the weighted average method to fuse the elevation of the buffer zone;

[0021] S53, after the buffer zone elevation is fused, the other areas are fused with the land DEM obtained by the drone and the water DEM obtained by the unmanned boat through the mosaic to new grid function in the GIS software to generate a complete water-land integrated all-terrain DEM.

[0022] Furthermore, the calculation formula for the elevation H after buffer zone fusion is:

[0023] H=αH A +(1-α)H S

[0024] Where: H is the elevation after buffer zone fusion; H A The surface elevation measured by the drone; H S is the bottom elevation measured by the unmanned vessel; α is the weight coefficient.

[0025] A UAV-USV-GIS-based integrated land-water all-terrain DEM survey system, including:

[0026] UAV route planning module: determine the scope of the study area, plan the UAV route, and deploy image control points;

[0027] Land DEM generation module: Based on the planned UAV route, the UAV is used for aerial survey to obtain ground point cloud data and images, which are then processed into land DEM and orthophoto images respectively;

[0028] Underwater terrain data measurement module: extract the boundary of the submerged water area, use the orthophoto to determine the scope of the submerged water area, and plan the measurement route of the unmanned vessel in combination with the actual terrain to measure the underwater terrain data;

[0029] Water area DEM generation module: processes underwater terrain data to generate water area DEM. Using RTK and bathymetric equipment, it evenly selects checkpoints for sampling measurements of bottom elevation to verify the accuracy of underwater terrain data in the water area DEM.

[0030] And, DEM fusion module: fuses land DEM and water DEM to generate a complete water-land integrated all-terrain DEM.

[0031] A computer storage medium stores a readable program, which can execute the above-mentioned UAV-USV-GIS-based water-land integrated all-terrain DEM survey method when the program is running.

[0032] An electronic device comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus;

[0033] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the above-mentioned UAV-USV-GIS-based water-land integrated all-terrain DEM survey method.

[0034] A computer program product includes computer instructions, which instruct a computing device to perform operations corresponding to the above-mentioned UAV-USV-GIS-based water-land integrated all-terrain DEM survey method.

[0035] Beneficial effects of the present invention:

[0036] 1. The present invention provides a UAV-USV-GIS-based water-land integrated all-terrain DEM survey method, which can achieve high-precision water-land integrated all-terrain Digital Elevation Model (DEM) measurement. Through multi-platform collaborative measurement and intelligent data fusion mechanism, it effectively solves the technical bottlenecks of traditional single measurement methods in subsidence water terrain modeling, such as low efficiency, inaccurate data at the water-land interface, and only being able to obtain elevation data of a single land or water area.

[0037] 2. The present invention uses drone orthophotos as the data basis for unmanned ship route planning, which can significantly reduce the manual planning cost of water obstacle avoidance measurement; adopts the heterogeneous data collaborative acquisition mode of LiDAR drones and unmanned ship sonars to obtain the water-land integrated full-terrain DEM of the subsidence area, and achieves a smooth transition of the water-land boundary by weighted elevation fusion at the water-land boundary; cooperates with RTK to verify the accuracy of the water-land integrated full-terrain DEM, and can evaluate the elevation accuracy of the overall DEM. This technology can be used to collect elevation information in water-containing areas, obtain specific subsidence conditions in areas such as subsidence waters, and provide an efficient and reliable technical solution for water-land integrated full-terrain three-dimensional modeling. The generated water-land integrated full-terrain DEM can be used for analysis of subsidence waters, disaster warning, resource assessment and other applications in multiple fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0039] Figure 1 This is a flow chart of the water-land integrated all-terrain DEM survey method based on UAV-USV-GIS technology of the present invention;

[0040] Figure 2 This is the route planning and image control point layout diagram of the study area of the present invention;

[0041] Figure 3 It is the land DEM map of the study area of this invention;

[0042] Figure 4 It is the DEM map of the water area in the study area of this invention;

[0043] Figure 5 It is a water-land integrated full-topography DEM map of the study area of this invention. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] Example 1

[0046] A UAV-USV-GIS-based integrated land-water all-terrain DEM survey method includes the following steps:

[0047] S1, determine the scope of the study area, plan the UAV route, and deploy image control points;

[0048] S11, determine the scope of the study area based on historical data and field surveys;

[0049] The scope of the study area should include water areas and their surrounding land areas, and cover as much as possible all areas that may be affected by subsidence.

[0050] S12, plan suitable drone routes based on the distribution of water areas in the study area;

[0051] Among them, when dividing the route into zones, the project should try to divide it into rectangles to facilitate the connection of the survey area. In addition, the terrain height difference within the aerial photography area should not be greater than 1 / 6 of the aerial photography altitude, and areas with large height differences should be divided into zones.

[0052] S13, image control point layout;

[0053] Image control points should be evenly distributed on the ground within the study area. After using high-precision GPS equipment to correct the coordinates through high-level control points near the mining area, the coordinates of the image control points should be measured for image geo-registration and coordinate accuracy verification to ensure the coordinate accuracy of the aerial survey data.

[0054] S2, according to the route planned in S1, uses drones to conduct aerial surveys, obtains point cloud data and images, and processes them into land DEM and orthophotos respectively;

[0055] The specific steps are:

[0056] S21, pre-flight inspection;

[0057] Aerial photography operations require checking system parameters and air damper control accuracy before takeoff. During flight, the ground station monitors the flight status in real time and handles abnormalities.

[0058] S22, GPS base station connected to the drone;

[0059] A GPS static observation station is set up at a known coordinate point, and observations are made simultaneously during the UAV's flight, so that the elevation data obtained by the UAV has accurate geographic information.

[0060] S23, drone data collection;

[0061] The drone is equipped with LiDAR (laser radar) and a high-resolution camera for simultaneous data collection. The LiDAR scans the ground using laser pulses to obtain ground point cloud data, while the camera captures images of the study area, providing visual data support.

[0062] S24, point cloud data processing;

[0063] The point cloud data collected by LiDAR is processed through software such as Hi-Target Business Center, Inertial Explorer, EPiCloud Center, and MicroStation CONNECT Edition. The main steps of point cloud data internal processing include static data processing, POS solution, flight strip clipping, point cloud filtering, elevation accuracy verification, etc., and finally a land DEM is generated.

[0064] S25, orthophoto generation;

[0065] After using software such as Photoshop to even out the light on the image, software such as Pix4Dmapper is used to perform operations such as image point control and aerial triangulation encryption. The drone aerial photography images are processed into products such as orthophotos (DOM) and digital surface models (DSM), and accuracy tests are performed.

[0066] S3, extract the boundary of the subsidence water area, use the orthophoto of the study area obtained in S2 to determine the scope of the subsidence water area, and plan the measurement route of the unmanned vessel based on the actual terrain to measure the underwater terrain data;

[0067] The specific steps are:

[0068] S31, extraction of subsidence water boundary;

[0069] Using multi-scale image segmentation, we calculated the difference vegetation index (VDVI) and the blue band standard deviation and mean difference water index (BSMW). We then extracted the boundaries of the subsidence area through threshold segmentation, and then optimized them using mathematical morphological filtering. This step ensured the precise determination of the boundaries of the water area, providing a basis for route planning for subsequent unmanned vessel water monitoring.

[0070] The calculation formula of the difference vegetation index VDVI is:

[0071]

[0072] Where: ρ green is the reflectivity of the green band, ρ red is the reflectivity of the red band, ρ blue is the reflectance of the blue band.

[0073] The calculation formula of the water body index BSMW, which is the difference between the standard deviation and the mean value of the blue band, is:

[0074]

[0075] Where: m represents the average value of the blue band in the image, std (blue) Represents the standard deviation of the blue band in the image.

[0076] S32: Use orthophotos of the study area to determine the extent of the subsidence waters and design the survey route of the unmanned vessel based on the actual terrain;

[0077] To ensure coverage of all submerged waters, a remotely controlled unmanned vessel should be manually operated to conduct a survey around the edge of the submerged area before designing the survey route. This will confirm the unmanned vessel's data range and refine the route measurement data. Furthermore, when setting the unmanned vessel's route, obstacles such as buildings above the water or structures protruding from the water should be avoided.

[0078] S33, underwater topographic data measurement

[0079] The unmanned boat is equipped with a sonar depth sounding system and GPS equipment to collect underwater terrain data such as water surface elevation, water depth and bottom elevation in real time; and through RTK technology combined with equipment such as measuring ropes or depth sounders, sampling inspection points are evenly selected, their water surface elevation and water depth are measured, and the bottom elevation of the sampling points is calculated, which is used as supplementary data for subsequent verification.

[0080] S4, processing the underwater topographic data to generate a water area DEM, and using the bottom elevation data of the sampling points to verify the accuracy of the underwater topographic data in the water area DEM;

[0081] The steps to generate a water area DEM include:

[0082] S41, underwater terrain data processing;

[0083] Through data processing software such as AutoPlanner and HydroSurvey, after smoothing and filtering to eliminate errors, the underwater terrain data directly measured by the unmanned vessel is used to extract plane coordinates, water surface elevation, water depth and bottom elevation values at a point spacing of 5m.

[0084] S42, generate water area DEM;

[0085] Based on underwater terrain data such as plane coordinates, water surface elevation, water depth and bottom elevation, the plane range of the water area DEM is determined by the water edge line, and the vertical benchmark is set in combination with the water surface elevation; the underwater terrain TIN is constructed using the bottom elevation data, and then the water area DEM is generated through operations such as raster clipping and terrain rendering.

[0086] S43, water area DEM data verification;

[0087] In order to ensure the accuracy of the water area DEM, the underwater elevation data of the sampling checkpoints are used to verify the accuracy of the underwater topography to ensure the reliability of the measurement results.

[0088] S5, merge the land DEM and the water DEM to generate a complete land-water integrated full-terrain DEM.

[0089] The steps for fusing land DEM and water DEM include:

[0090] S51, data registration;

[0091] Unify the coordinate systems and elevation datums of the land DEM and the water DEM to ensure that the land DEM and the water DEM have the same spatial reference

[0092] S52, fusion method establishment;

[0093] After fusion, the water area DEM is used for the water area; a 100 cm buffer zone is established at the junction of the water area and the land area, and the elevation of the buffer zone is fused using the weighted average method. The elevation H after buffer zone fusion is calculated as follows, and the Laplacian smoothing algorithm is applied to eliminate splicing traces;

[0094] H=αH A +(1-α)H S

[0095] Where: H is the elevation after buffer zone fusion, unit is m; H A is the surface elevation measured by the drone, in meters; H S is the bottom elevation measured by the unmanned vessel, in meters; α is the weight coefficient, which is 0.5.

[0096] S53, water-land elevation data fusion;

[0097] After the buffer zone elevation is fused, the land DEM obtained by drones in other areas and the water DEM obtained by unmanned boats are fused through the mosaic to new raster function in GIS software such as ArcGIS and QGIS to generate a complete water-land integrated all-terrain DEM.

[0098] S54, fusion data accuracy verification;

[0099] Verification points are evenly distributed in water areas and ground areas to test the accuracy of the integrated water-land all-terrain DEM.

[0100] Based on similar inventive concepts, an embodiment of the present invention also provides a computer storage medium storing a readable program, which, when the program is running, can execute the above-mentioned UAV-USV-GIS-based water-land integrated all-terrain DEM survey method.

[0101] Based on similar inventive concepts, an embodiment of the present invention provides an electronic device, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus;

[0102] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the above-mentioned UAV-USV-GIS-based water-land integrated all-terrain DEM survey method.

[0103] Based on similar inventive concepts, an embodiment of the present invention also provides a computer program product, including computer instructions, which instruct a computing device to perform operations corresponding to the above-mentioned UAV-USV-GIS-based water-land integrated all-terrain DEM survey method.

[0104] Example 2

[0105] In this example, a study area is used as an example. There are subsidence areas caused by mining in this area. It is difficult to obtain a water-land integrated full-terrain DEM using only drones and unmanned boats. In this implementation case, UAV-USV-GIS technology is used for surveying. The specific steps are as follows:

[0106] Step 1: Setting the scope of the study area and planning the UAV route.

[0107] Step 1.1: Determine the scope of the study area. The scope of the study area should be determined by analyzing historical data and field surveys. The study area should include the water area and its surrounding land areas, and should cover all areas that may be affected by subsidence as much as possible.

[0108] Step 1.2: Drone route planning. Design a suitable drone route based on the distribution of water in the study area. In this case, the drone's lateral overlap is set to 60%, the flight speed is set to 8m / s, and the flight altitude is designed to be 106m.

[0109] When zoning routes, the project should prioritize rectangular divisions to facilitate the alignment of survey areas. Furthermore, the terrain height difference within the aerial photography area should not exceed 1 / 6 of the aerial photography altitude. Areas with large height differences should be divided into zones. In this implementation case, nine flights were set for the photography area.

[0110] Step 1.3: Layout of image control points. Image control points should be evenly distributed on the ground within the study area, such as Figure 2 As shown, after using high-precision GPS equipment to correct coordinates at high-level control points near the mining area, the coordinates of the image control points are measured for image georegistration and coordinate accuracy verification to ensure the coordinate accuracy of the aerial survey data. In this implementation case, 11 image control points are set.

[0111] Step 2: LiDAR UAV aerial survey and data acquisition

[0112] Step 2.1, Pre-flight Check. Aerial photography operations require checking system parameters and damper control accuracy before takeoff. During flight, the ground station monitors the flight status in real time and handles any anomalies.

[0113] Step 2.2: Connect the GPS base station to the drone. Set up a GPS static observation station at a known coordinate point and observe it while the drone is in flight, ensuring that the elevation data obtained by the LiDAR drone has accurate geographic information.

[0114] Step 2.3: UAV data collection. The drone is equipped with a LiDAR system and a high-resolution camera for simultaneous data collection. The LiDAR system scans the ground using laser pulses, generating ground point cloud data; the camera captures images of the study area, providing visual data support.

[0115] Step 2.4, point cloud data processing. LiDAR point cloud data is processed through software such as Hi-Target Business Center, Inertial Explorer, EPiCloud Center, and MicroStation CONNECT Edition. The main steps of internal data processing include static data processing, POS solution, flight strip clipping, point cloud filtering, elevation accuracy verification, etc., and finally a land DEM is generated. Figure 3 This is the land DEM of a certain study area. It can be seen that the elevation of the land area changes significantly, while the water area in the middle has a gentle elevation fluctuation because it is generated based on a small amount of water surface elevation monitored by drones.

[0116] Step 2.5: Generate orthophotos. After image uniformity is performed using software such as Photoshop, image point manipulation and aerial triangulation are performed using software such as Pix4Dmapper. The drone aerial images are then processed into orthophotos (DOMs) and digital surface models (DSMs), and accuracy tests are performed.

[0117] Step 3: Unmanned vessel depth measurement and data collection;

[0118] Step 3.1: Extract the boundaries of the submerged waters. Using multi-scale image segmentation, we calculated the difference vegetation index (VDVI) and the blue band standard deviation and mean difference water body index (BSMW). We then extracted the water boundaries using threshold segmentation. This was then optimized using mathematical morphological filtering. This step ensured the precise determination of the water boundaries, providing a basis for route planning for subsequent unmanned vessel water monitoring.

[0119]

[0120] Where: ρ green is the reflectivity of the green band, ρ red is the reflectivity of the red band, ρ blue is the reflectance of the blue band.

[0121]

[0122] Where: m represents the average value of the blue band in the image, std ( bl ue ) represents the standard deviation of the blue band in the image.

[0123] Step 3.2: Unmanned vessel route planning: Use the orthophoto of the study area to determine the extent of the subsidence waters, and design the unmanned vessel's survey route based on the actual terrain.

[0124] Among them, in order to ensure that all subsidence waters are covered, before designing the measurement route, the unmanned boat should be manually remotely controlled to sail and measure around the edge of the subsidence area to determine the data range of the unmanned boat and improve the route measurement data.

[0125] Among them, when setting up unmanned boat routes, obstacles such as buildings above the water surface or structures exposed to the water surface should be avoided.

[0126] Step 3.3: Underwater topography data measurement. The unmanned vessel is equipped with a sonar depth sounding system and GPS equipment to collect underwater topography data in real time. Using RTK technology combined with equipment such as a measuring rope or depth sounder, sampling points are evenly selected, and their water surface elevation and depth are measured. The bottom elevation of the sampling points is calculated and used as supplementary data for subsequent verification.

[0127] Step 4: underwater terrain data processing.

[0128] Step 4.1: Underwater topographic data processing. Using data processing software such as AutoPlanner and HydroSurvey, after smoothing and filtering to eliminate errors, extract the plane coordinates, water surface elevation, water depth, and bottom elevation of the original data at a 5-meter point spacing.

[0129] Step 4.2, generate water area DEM. Extract water depth value of water edge line, build water depth terrain TIN, clip grid, render terrain and other operations to generate water area DEM, such as Figure 4 As shown, it can be seen that this method can measure the underwater terrain.

[0130] Step 4.3: Verify the water area DEM data. To ensure the accuracy of the water area DEM, use the bottom elevation data of the sampling checkpoints to verify the accuracy of the underwater topography and ensure the reliability of the measurement results.

[0131] Step 5: Data fusion and final model generation.

[0132] Step 5.1: Data registration. To ensure that the land DEM and the water DEM have the same spatial reference, unify their coordinate systems and elevation datums.

[0133] Step 5.2: Establish the fusion method. Use the water area DEM for the water area. Create a 100cm buffer zone at the interface between the water area and the ground area. Use the weighted average method for fusion, as shown below. Apply the Laplacian smoothing algorithm to eliminate splicing artifacts.

[0134] H=αH A +(1-α)H S

[0135] Where: H is the elevation after buffer zone fusion; H A The surface elevation measured by the drone; H S is the bottom elevation measured by the unmanned vessel. α is the weight coefficient, which is set to 0.5.

[0136] Step 5.3: Fusion of water-land elevation data. After the elevation of the water boundary area is fused, the other areas are fused by mosaicking the land DEM obtained by the drone with the water DEM obtained by the unmanned boat through the mosaicking function in GIS software such as ArcGIS or QGIS to generate a complete water-land integrated full-terrain DEM. Figure 5 As shown in the figure, it can be seen that the land-water integrated full-terrain DEM can display the elevation of land areas and water areas.

[0137] Step 5.4: Verify the accuracy of the fused data. Verify the accuracy of the integrated land-water DEM by evenly distributing verification points in the water and ground areas.

[0138] Example 3

[0139] Based on the UAV-USV-GIS-based water-land integrated all-terrain DEM survey method proposed in Example 1, this embodiment proposes a UAV-USV-GIS-based water-land integrated all-terrain DEM survey system, including:

[0140] UAV route planning module: determine the scope of the study area, plan the UAV route, and deploy image control points;

[0141] Land DEM generation module: Based on the planned UAV route, the module uses UAVs for aerial surveying to obtain point cloud data and images, and processes them into land DEM and orthophotos respectively;

[0142] Underwater terrain data measurement module: extract the boundary of the submerged water area, use the orthophoto to determine the scope of the submerged water area, and plan the measurement route of the unmanned vessel in combination with the actual terrain to measure the underwater terrain data;

[0143] Water area DEM generation module: processes underwater terrain data to generate water area DEM. Using RTK and bathymetric equipment, it evenly selects checkpoints for sampling measurements of bottom elevation to verify the accuracy of underwater terrain data in the water area DEM.

[0144] And, DEM fusion module: fuses land DEM and water DEM to generate a complete water-land integrated all-terrain DEM.

[0145] The method of the present invention can be implemented in hardware, firmware, or as software or computer code that can be stored in a recording medium (such as a CDROM, RAM, floppy disk, hard disk or magneto-optical disk), or as computer code that is originally stored in a remote recording medium or a non-temporary machine-readable medium downloaded over a network and will be stored in a local recording medium, so that the method described herein can be stored in such software processing on a recording medium using a general-purpose computer, a special-purpose processor or programmable or special-purpose hardware (such as an ASIC or FPGA). It will be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component (e.g., RAM, ROM, flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by a computer, a processor or hardware, the method described herein is implemented. In addition, when a general-purpose computer accesses the code for implementing the method shown here, the execution of the code converts the general-purpose computer into a special-purpose computer for executing the method shown here.

[0146] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A UAV-USV-GIS-based integrated land-water all-terrain DEM survey method, characterized in that: The following steps are involved: Determine the scope of the study area, plan the drone route, and deploy image control points; According to the planned drone route, use drones to conduct aerial surveys, obtain ground point cloud data and images, and process them into land DEM and orthophoto images respectively; Extract the boundary of the submerged water area, use the orthophoto to determine the scope of the submerged water area, and plan the measurement route of the unmanned vessel in combination with the actual terrain to measure underwater terrain data; Process underwater terrain data to generate a water area DEM. Use RTK and bathymetric equipment to evenly select checkpoints for sampling measurements of bottom elevation to verify the accuracy of underwater terrain data in the water area DEM. The land DEM and water DEM are merged to generate a complete land-water integrated full-terrain DEM.

2. The method for land-water integrated all-terrain DEM survey based on UAV-USV-GIS according to claim 1 is characterized in that: The drone is equipped with a lidar and a camera to acquire ground point cloud data and images respectively; The ground point cloud data is processed through static data processing, POS solution, flight strip clipping, point cloud filtering, and elevation accuracy verification to finally generate a land DEM; The image is first homogenized, and then image control points and aerial triangulation operations are performed to obtain an orthophoto.

3. The method for land-water integrated all-terrain DEM survey based on UAV-USV-GIS according to claim 1 is characterized in that: The process of extracting the boundary of the subsidence water area is as follows: using multi-scale image segmentation, calculating the difference vegetation index, the difference water index between the standard deviation and the average value of the blue band, and extracting the boundary of the subsidence water area through threshold segmentation.

4. The method for land-water integrated all-terrain DEM survey based on UAV-USV-GIS according to claim 1 is characterized in that: Underwater terrain data processing includes: after smoothing and filtering to eliminate errors, the underwater terrain data directly measured by the unmanned vessel is extracted with a point spacing of 5m to obtain the plane coordinates, water surface elevation, water depth and bottom elevation values.

5. The method for land-water integrated all-terrain DEM survey based on UAV-USV-GIS according to claim 1 is characterized in that: The steps for fusing land DEM and water DEM include: S51, unify the coordinate system and elevation datum of land DEM and water DEM S52 establishes a buffer zone at the junction of the water area and the land area, and uses the weighted average method to fuse the elevation of the buffer zone; S53, after the buffer zone elevation is fused, the other areas are fused with the land DEM obtained by the drone and the water DEM obtained by the unmanned boat through the mosaic to new grid function in the GIS software to generate a complete water-land integrated all-terrain DEM.

6. The method for land-water integrated all-terrain DEM survey based on UAV-USV-GIS according to claim 5 is characterized in that: The calculation formula for the elevation H after buffer zone fusion is: H=αH A +(1-α)H S Where: H is the elevation after buffer zone fusion; H A The surface elevation measured by the drone; H S is the bottom elevation measured by the unmanned vessel; α is the weight coefficient.

7. A UAV-USV-GIS-based integrated land-water all-terrain DEM survey system, characterized by: include: UAV route planning module: determine the scope of the study area, plan the UAV route, and deploy image control points; Land DEM generation module: Based on the planned UAV route, the UAV is used for aerial survey to obtain ground point cloud data and images, which are then processed into land DEM and orthophoto images respectively; Underwater terrain data measurement module: extract the boundary of the submerged water area, use the orthophoto to determine the scope of the submerged water area, and plan the measurement route of the unmanned vessel in combination with the actual terrain to measure the underwater terrain data; Water area DEM generation module: processes underwater terrain data to generate water area DEM. Using RTK and bathymetric equipment, it evenly selects checkpoints for sampling measurements of bottom elevation to verify the accuracy of underwater terrain data in the water area DEM. And, DEM fusion module: fuses land DEM and water DEM to generate a complete water-land integrated all-terrain DEM.

8. A computer storage medium storing a readable program, characterized in that: When the program is running, it can execute the water-land integrated all-terrain DEM survey method based on UAV-USV-GIS as described in any one of claims 1 to 6.

9. An electronic device, characterized in that: include: A processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the UAV-USV-GIS-based water-land integrated all-terrain DEM survey method according to any one of claims 1 to 6.

10. A computer program product comprising computer instructions, characterized in that The computer instructions instruct the computing device to perform operations corresponding to the UAV-USV-GIS-based water-land integrated all-terrain DEM survey method as described in any one of claims 1 to 6.

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