83 results about "Triangular grid" patented technology

The invention relates to the technical field of computer-aided manufacturing, and provides a staged processing real-time cutting simulation method and system.The method comprises the steps that S1, initialization modeling is conducted, specifically, a blank voxel grid model, a tool body voxel grid and a triangular grid are built; s2, performing a first simulation stage of low-precision real-time cutting dominated by voxel grids, judging a space overlapping relationship between the tool body voxel grids and the blank voxel grids in real time so as to determine a voxel region to be removed, and deleting blank voxels in the overlapping region through Boolean operation; s3, in the execution process of the first simulation stage, monitoring a preset multi-dimensional switching trigger condition in real time, and when any condition or a combination of multiple conditions is met, entering a second simulation stage; and S4, a second simulation stage of high-precision real-time cutting with the triangular network as the dominant is carried out, the voxel grid intermediate workpiece is converted into a transition triangular grid, and high-precision cutting calculation is carried out based on the triangular grid. And the efficiency-precision contradiction is broken through through a staged strategy.

The utility model discloses a silicon capacitor electrode structure and a silicon capacitor, which can further improve the capacitance of a capacitor in a limited space by nesting, combining and arranging a plurality of groups of element arrays distributed in a triangular grid mode more reasonably and precisely, so that the capacitor can store more charges.

The invention relates to the technical field of computer graphics, in particular to a three-dimensional geological section real-time cutting method and system and a storage medium, and the method comprises the steps: constructing a BVH tree to accelerate the cutting of a three-dimensional geological model, and calculating the projection of intersecting line segments on a cutting surface two-dimensional coordinate system to obtain a projection line segment set; constructing an undirected graph structure based on the projection line segment set; and extracting a closed profile contour based on the undirected graph structure, subdividing a triangular grid, and rendering and displaying. The implementation of the scheme can break through the traditional preprocessing dependence, and improve the profile generation efficiency and the visualization integrity.

The invention provides an intelligent grading identification method for a potential infiltration risk area of a drainage pipe network, and relates to the technical field of risk identification of the drainage pipe network. Establishing spatial relation mapping between triangular grid units of the surface water-underground water coupling model and pipe sections of the drainage pipe network model, calculating hourly liquid level difference time sequence data by utilizing underground water level time sequence data and corresponding pipe section liquid level time sequence data which are obtained through simulation calculation, and constructing risk indexes according to the hourly liquid level difference time sequence data; and then constructing an uncertainty scene sample set and respectively inputting the two models to obtain corresponding simulation calculation results, calculating to obtain a risk index corresponding to each pipe section, and judging a grading result of a potential infiltration risk area according to the risk indexes. Simulation calculation and intelligent diagnosis analysis are fused, and efficient identification of the potential infiltration risk area of the drainage pipe network is achieved on the premise that large-scale sensor deployment is not needed.

The invention relates to the technical field of intelligent power transmission and distribution line emergency lighting and unmanned aerial vehicle dynamic deployment optimization, and discloses a power transmission and distribution line emergency repair lighting system and method based on wireless networking unmanned aerial vehicle lighting. Establishing a two-dimensional coordinate and an equilateral triangle mesh, and taking a center coordinate; setting the upper limit and height of the unmanned aerial vehicle, establishing an illumination cone, obtaining a light spot radius according to an opening angle, and comparing a grid distance with the radius to judge that irradiation can be performed; the illuminance is accumulated and compared with a threshold value to reach the standard; taking a substandard proportion as a target and setting an overlapping proportion and a safety center distance as constraints; assuming the candidate points one by one, deploying the maximum gain, heightening or adjusting the angle of the gap area and rechecking the constraint; calculating a link threshold according to field parameters to construct an ad hoc network, and selecting a relay to recover disconnection; performing balanced scheduling by using the average deviation and the neighborhood positive gap after the global standard is reached; and finally activating the recording parameters and summarizing the situation map.

The invention discloses a bridge deck slab wet joint fine finite element simulation method based on three-dimensional scanning, and relates to the technical field of bridge engineering, and the method comprises the steps: carrying out on-site three-dimensional scanning to obtain wet joint chiseling interface morphology contour data, and obtaining three-dimensional point cloud data; performing data restoration on the three-dimensional point cloud data; curved surface splicing optimization is carried out based on the point cloud data, the number and size adjustment of triangular grids is simplified, and a three-dimensional curved surface model is reconstructed; performing curved surface closing and repairing on the three-dimensional curved surface model, and converting the three-dimensional curved surface model into a three-dimensional solid model; carrying out finite element modeling and analysis on the three-dimensional solid model; obtaining a finite element result of the bridge deck concrete wet joint interface, and evaluating the cracking risk of the concrete wet joint according to a calculation result; according to the method, the actual cracking and damage conditions of the joint interface can be accurately reflected by adopting the real appearance modeling of the wet joint, and the method has important guiding significance on the crack resistance evaluation and optimization design of the wet joint of the bridge deck slab.

The application discloses an aircraft grid generation method and device based on conformal mapping and topological segmentation, equipment and a storage medium, relates to the technical field of computational fluid dynamics, and comprises the following steps: generating a surface unstructured grid according to an aircraft model, conformally mapping the surface unstructured grid to a parameter domain plane grid through Ricci flow, and calculating the compression rate of the parameter domain plane grid; if the compression rate is less than a first threshold value, extracting an isoline corresponding to a second threshold value; locating a triangular grid corresponding to an isoline discrete point in the parameter domain plane grid by using a spatial partition algorithm, inserting the discrete point into the grid according to the vertex distance and edge distance relationship, forming a closed internal boundary through a one-dimensional boundary recovery operation, and determining a corresponding region; inversely mapping the region back to a three-dimensional surface, updating the surface grid, and repeating the mapping and judging steps until the compression rate meets the requirement, and setting the parameter domain plane grid as a target aircraft grid, so that the efficiency of generating the aircraft grid is improved.

The invention relates to the technical field of urban flood simulation, in particular to an urban flood simulation method based on a physical information neural network and multi-GPU calculation. The method comprises the following steps that a computational domain in urban flood simulation is divided into triangular grids, a data matrix is established, a solving process is divided into reconstruction calculation, flux calculation, bottom slope and friction source item calculation and flux updating, and then a two-dimensional shallow water equation finite volume solving process is constructed; a physical information neural network is used for replacing a numerical calculation step in a finite volume solving process of a two-dimensional shallow water equation, a simulation prediction model is obtained through training of the physical information neural network, and the simulation prediction model is used for rapid calculation of a surface runoff process; simulation coupling is carried out on the urban pipe network drainage process and the surface runoff process in urban flood simulation, and a drainage calculation model is constructed. According to the invention, rapid, stable and extensible simulation of large-scale urban flood is realized through an urban flood simulation technology.

This invention relates to the field of orchard navigation technology, specifically a 3D method for orchard operations based on a grid map. The method includes: constructing an orchard point cloud map using a mapping algorithm; filtering the acquired 3D point cloud map and constructing a triangular grid map of the orchard, embedding the orchard's GPS information into the triangular grid map; based on the triangular grid map with GPS information, performing ICP registration between the point cloud data scanned by the LiDAR and the points on the triangular grid map using the RMCL 3D positioning algorithm, outputting the 3D pose of the operation robot in the orchard; updating the 3D pose of the operation robot in the orchard using GNSS information; planning the navigation path of the operation robot using grid navigation based on the GPS information of the target point; and controlling the operation robot to dynamically avoid obstacles and navigate to the target point. This invention enables precise positioning and autonomous navigation of the operation robot in hilly orchards, allowing it to complete tasks such as orchard inspection, plant protection, harvesting, and transportation.

The invention belongs to the field of earthquake and stress distribution calculation, and particularly relates to an earthquake deformation and stress distribution calculation method and system based on a Green function. The method comprises the following steps: acquiring a triangular mesh and a to-be-measured point of a fault; constructing an earth fixed coordinate system, a triangular dislocation coordinate system and an angular dislocation coordinate system based on the triangular mesh of the fault; determining a transformation matrix to obtain a coordinate system; calculating interior angles of three vertexes of the triangular mesh in the coordinate system and corresponding supplementary angles, selecting equivalent configuration based on the supplementary angles, calculating barycentric coordinates of orthogonal projection of the to-be-measured point on the triangular dislocation plane, and selecting configuration based on a partition inequality of the barycentric coordinates; according to configuration, a Burgers function is obtained through calculation by using a solid angle formula, incomplete displacement contributions of all angular dislocations are superposed, and a complete displacement field containing slip continuity correction is obtained; a stress field is calculated based on a complete displacement field or through a Green function of strain. And the seismic deformation and stress distribution calculation performance is obviously improved.

The invention discloses a terrain generation and import system and method based on geographic raster data. The system comprises a raster format data analysis module used for extracting an elevation matrix and size parameters of TIFF format digital elevation model data; the three-dimensional grid generation module is used for generating a regular triangular grid based on the elevation matrix; the file standard format export module is used for serializing the grid data into an OBJ format and generating a matched MTL material file; and the dynamic import module is used for analyzing an OBJ file through an Assimp library and creating interactive terrain assets in an unreal engine 5. The problems of low efficiency, precision loss, lack of real-time performance and complex operation in traditional topographic data processing are solved, and real-time visualization of topographic data is realized by automatically analyzing TIFF format DEM data, converting the TIFF format DEM data into an OBJ format three-dimensional model and dynamically importing the OBJ format three-dimensional model in an unreal engine 5. The system improves the automation degree and application efficiency of terrain processing, and is suitable for the fields of geographic information systems, game development, virtual simulation and the like.

The application discloses a kind of soil organic carbon three-dimensional space mapping methods of fusing ground visible near infrared spectrum, it is related to soil property prediction technical field, in the method: based on the range of study area setting sampling point, extracts training set sampling point surface field ground visible near infrared spectrum principal component data, application Kennard-stone algorithm optimization reduces training set sampling point to one fourth, then obtain the field ground visible near infrared spectrum and soil organic carbon data of different depth of sampling point profile, and determine the best triangular grid parameter;Then construct SPDE model and solve using finite element method, make Gaussian Markov random field as spatial random effect, the principal component data of field ground visible near infrared spectrum of different depth of each sampling point profile as environmental covariate, application INLA model is carried out soil organic carbon three-dimensional space prediction, obtain the posterior distribution estimate, and soil organic carbon three-dimensional space mapping is carried out accordingly.The application can quickly obtain field ground visible near infrared spectrum, improve data acquisition efficiency, while fusing field ground visible near infrared spectrum principal component data, improve model prediction accuracy.

The invention provides an electromagnetic scattering modeling method based on a learnable primary function, and relates to the technical field of radar detection and remote sensing imaging, and the method comprises the steps: carrying out the parameter analysis of a discrete triangular mesh on the surface of an electromagnetic scattering three-dimensional conductor target, and obtaining an initial feature set composed of mesh edge features, surface patch geometric features and geometric and incident parameters; based on the learnable basis function, constructing a current prediction model by using the local branch layer, the global branch layer and the feature fusion layer; based on a residual error loss function, training a current prediction model by using the initial feature set to obtain a trained current prediction model, and completing electromagnetic scattering modeling; the trained current prediction model is used for analyzing the discrete triangular mesh to obtain a plurality of induced current distribution of each patch. The electromagnetic scattering modeling method solves the problems that an existing electromagnetic scattering modeling method depends on specific physical approximation and is high in calculation complexity.

The application discloses a gradient coil design method and device, electronic equipment and a storage medium, applied to the technical field of superconducting magnetic resonance imaging systems, in order to solve the problems of large coil inductance and decreased magnetic field climbing rate, the gradient coil is an axisymmetric gradient coil, the method can obtain a triangular grid corresponding to the skeleton surface by discretizing the skeleton surface to be wired, then further performs flow function calculation according to the triangular grid, determines the corresponding initial flow function distribution, minimizes the flow function extreme value as a first objective function, and combines the first preset boundary condition to perform first nonlinear programming on the initial flow function distribution to obtain a new flow function distribution; and the parameter information of the gradient coil is determined according to the new flow function distribution. In the application, the flow function extreme value is taken as the first objective function, the flow function distribution is optimized, the inductance is minimized, the linearity of the gradient magnetic field is improved, and the demand of the fast imaging scene is better met.

The application provides a CAD model reconstruction method and device for topology optimization results, and relates to the technical field of computer modeling. The method comprises the following steps: grid preprocessing, component type grid segmentation, sheet type grid segmentation, obtaining at least two sub-grid sheets, parameterizing each sub-grid sheet to obtain a final parameterization result, performing uniform interpolation sampling based on the final parameterization result to obtain sampling points, generating a spline surface by using the sampling points, assembling the spline surface, and generating a reconstructed CAD model corresponding to the three-dimensional topology optimization result. The grid model reconstruction method has the advantages of high automation degree, strong realizability, simple operation, etc., is not limited to a tubular topology optimization structure, has no obvious difference in processing tubular and non-tubular model characteristics, has stronger universality, can adapt to the diversity demand of industrial structure optimization, and can improve the reconstruction efficiency and reconstruction effect of the triangular grid model to the CAD model.

The application belongs to the field of finite element grid encryption, and specifically provides a two-dimensional finite element grid non-conformal h-type adaptive encryption method to overcome the shortcoming that the traditional finite element method cannot perform non-conformal encryption. The application adopts a normalized edge-based function to process a non-conformal area in a triangular grid, so that the finite element method can solve unknown electric field intensity by using a non-conformal grid, and then calculate a numerical solution of a radar scattering cross section by using the obtained electric field intensity. In combination with an error estimation method, the application can freely encrypt a grid with a large error contribution, and can efficiently reduce the error between the numerical solution and the true solution. The application effectively avoids the increase of distorted grids in the encryption process without introducing additional unknown quantities, and ensures the grid quality. Meanwhile, the application realizes grid adaptive encryption, and can reduce unknown quantities and improve the solving precision compared with uniform encryption.

The invention discloses a triangular mesh shape-finding optimization method based on GH and fluid dynamics. The method comprises the following steps: step 1, storing a triangular mesh needing shape-finding optimization in a tool of a Grasshopper parameterization process in a datamation form; step 2, applying a force to each side of the triangular unit to homogenize the triangular unit; and 3, restoring the plurality of triangular optimization units into the triangular mesh to form the triangular mesh after shape finding optimization. The invention relates to the technical field of building external envelope engineering, and can solve the problems that in the prior art, triangular grid units are not uniform in side length, and triangular geometrical shapes are classified in multiple types.

A radar cover uniform variable thickness inner surface modeling method based on finite element grid thickness mapping, comprising: obtaining the thickness-coordinate discrete point set of the radar cover outer shape surface and at least two main sections; fitting to obtain the thickness distribution function of each main section; performing finite element triangular grid division on the outer shape surface to obtain the center point coordinates and normal vector of each unit; according to the center point spatial coordinates and the thickness distribution function, interpolating to calculate the design thickness value of the point; offsetting the design thickness value along the unit normal direction to generate the three-dimensional point cloud corresponding to the inner surface; and finally reconstructing the continuous and smooth inner surface curve through reverse engineering. The present application ensures that the actual wall thickness is highly consistent with the design thickness through three-dimensional normal offset, avoiding the normal error of the traditional two-dimensional section method; based on the point cloud reverse reconstruction, the G1 / G2 continuous high-quality inner surface can be obtained, significantly improving the modeling accuracy and efficiency, and being suitable for the digital modeling of various complex variable thickness radar covers.

The application discloses a cross-scale large-scale electromagnetic surface grid generation method with periodic fine features, comprising the following steps: reading a cross-scale electromagnetic geometric model with periodic fine features, setting a replication direction and a number; setting a periodic boundary condition of the electromagnetic geometric model, determining a source surface and a target surface of the replication direction, extracting a boundary line, and establishing a mapping relationship between the source surface, the target surface and the boundary line; discretizing the electromagnetic geometric model to generate a discrete background triangular grid; generating a size field of the overall geometry according to the periodic fine features and the cross-scale features of the electromagnetic geometric model; generating and merging surface grids of the source surface, the target surface and the remaining surfaces according to the discrete background triangular grid and the size field and the mapping relationship; and batch replicating and merging the surface grids according to the replication direction and the number to generate a cross-scale large-scale electromagnetic surface grid with periodic fine features.

The application discloses a kind of based on neural shader's fast reconstruction textured three-dimensional model method, comprising the following steps: step S1, a group of images are photographed at different angles around the object to be reconstructed, and the foreground image, camera pose and internal parameter are obtained by pre-processing image as training data, step S2, establish initial triangular grid, step S3, establish differentiable renderer, it contains rasterization and neural shader two parts vertex and texture of the model of the application are divided into two optimizers, model is successively differentiable rasterization and differentiable neural shader, obtain rendering chart, calculate loss with original chart and back propagation, compared with the ray step of implicit function of other reconstruction methods, the time of rasterization is significantly shorter, since the application of neural shader, the model obtained can be used to paste texture with trained neural shader, so that fast reconstruction textured three-dimensional model is realized.

The application provides a three-dimensional complex fault model construction method based on deduction and related equipment, including: determining fault data of a target area, and extracting and analyzing the fault data to determine attribute data, planar fault discrete points and profile elevation data; determining a first fault throw and a discrete point throw change type, and determining hanging wall discrete point coordinates and footwall discrete point coordinates according to the first fault throw and the discrete point throw change type; determining a stratigraphic layer spacing, determining a second fault throw change range and a second fault throw according to the stratigraphic layer spacing and the first fault throw; prioritizing the faults, determining a priority order, and performing intersection deduction according to the priority order to determine a first stratigraphic model; performing intersection deduction on the faults and special geological structures to determine a second stratigraphic model; encrypting the discrete points of each fault in the stratigraphic model to determine a discrete point set, and performing Delaunay triangular grid subdivision on the discrete points to generate a fault surface model.

This invention discloses a GPU-based method, device, and medium for rapid 3D orebody inversion, relating to the field of 3D orebody inversion technology. The method includes importing multi-source exploration data, generating observation data in a unified coordinate system, establishing a 3D voxel grid, and acquiring a data acquisition configuration package; performing multiphysics forward modeling to generate normalized prediction vectors and normalized residual vectors, establishing the forward and transpose interfaces of sensitivity operators, constructing update direction vectors, and generating a pre-projection parameter field; sequentially performing box-constrained projection, total variation projection, and wavelet sparse projection on the pre-projection parameter field to obtain a sparse parameter field and generate the final parameter field; generating a 3D grade voxel array, calculating grade segmentation thresholds, extracting the orebody connected body set, generating a orebody triangular grid and an orebody existence probability voxel array, and acquiring a digital twin base data package. This method shortens computation time, reduces storage pressure, and improves the accuracy and practicality of the inversion.

The invention relates to the technical field of satellite navigation, in particular to a GNSS (Global Navigation Satellite System) suppressing interference coverage rate evaluation method and system based on an irregular triangular grid, and the method comprises the steps: dividing a to-be-evaluated region into a determined region, a fuzzy region and a non-important region according to a maximum interference distance; selecting key feature points from the digital terrain surface model of the to-be-analyzed area by using a high-pass filter, and constructing an irregular triangular grid; judging an area to which each grid point in the triangular grid belongs, taking a GNSS interference source erection point as a starting point, carrying out visual field analysis on the to-be-evaluated area, adjusting the importance of each grid point through an interference scale factor, and updating the irregular triangular grid; and sampling the grid points, determining the disturbed state of each grid point, calculating the area of the grid points in the disturbed state, and obtaining the GNSS suppression interference coverage rate of the to-be-evaluated region based on the area of the grid points in the disturbed state and the area of the to-be-evaluated region. According to the method, the evaluation efficiency and the accuracy can be well balanced.

The invention discloses a water body rendering method, system and device for a reservoir and a medium, and the method is characterized in that the method comprises the steps: obtaining the ground height and initial water surface depth of each grid unit in a simulation domain grid of the reservoir; determining a water surface height difference value corresponding to each grid unit on the basis of the ground height and the initial water surface depth, determining an adjacent height difference value between each grid unit and a plurality of adjacent grid units on the basis of each water surface height difference value, and determining a water surface height difference value between each grid unit and the plurality of adjacent grid units on the basis of the adjacent height difference value and a preset pipeline parameter, according to the initial water surface depth, calculating to obtain water flow flux, obtaining a water body volume variation corresponding to each grid unit in a preset time period based on the water flow flux, calculating to obtain an update value based on the water body volume variation, and determining a target water surface depth based on the update value and the initial water surface depth; and rendering the target water surface depth to the surface of the triangular mesh to obtain a water body rendering result of the reservoir. According to the method and the device, rapid water body rendering can be realized at the Web end.

The invention provides a three-dimensional model construction method and system for topographic survey, and belongs to the technical field of model construction, and the method comprises the steps: segmenting a satellite image of a target survey region based on the topographic complexity, and obtaining a complex topographic region and an open topographic region; acquiring laser scanning data of the complex terrain area and low-altitude image data of the open terrain area; performing data fusion on the laser scanning data and the low-altitude image data to obtain a target data set corresponding to the target survey area; constructing a regular grid model corresponding to the target survey area based on the target data set; constructing an irregular triangular grid model corresponding to the target surveying area based on the laser scanning data; and fusing the regular grid model and the irregular triangular grid model to obtain a three-dimensional model of the target surveying area. According to the three-dimensional model construction method and system for topographic survey provided by the invention, the modeling precision can be improved.

The invention discloses a tunnel overall large deformation measurement method and device based on laser scanning, and relates to the technical field of laser ranging and tunnel deformation measurement, and the method comprises the steps: S1, collecting the point cloud data of a multi-stage tunnel primary support section through laser scanning, and constructing a three-dimensional triangular mesh model Mp of each stage; s2, constructing a reference three-dimensional triangular mesh model M0 of a tunnel primary support section; s3, calculating a grid vertex normal vector and a grid vertex normal vector straight line of the reference three-dimensional triangular grid model M0; s4, obtaining an intersection relation list of the grid vertex normal vector straight line of M0 and Mp through a hierarchical bounding box detection algorithm; s5, calculating the deformation of the Mp according to the intersection relation list; and S6, subtracting the deformation of the three-dimensional triangular mesh model in other periods from the deformation of the M1 to obtain the relative deformation of each period. According to the hierarchical bounding box detection algorithm, the large-scale point cloud data processing precision is improved, the deformation analysis efficiency is effectively improved, and the tunnel deformation measurement cost is reduced.

This invention discloses a GPU-based method, device, and medium for rapid 3D orebody inversion, relating to the field of 3D orebody inversion technology. The method includes importing multi-source exploration data, generating observation data in a unified coordinate system, establishing a 3D voxel grid, and obtaining a data acquisition configuration package; performing multiphysics forward modeling to generate normalized prediction vectors and normalized residual vectors, establishing the forward and transpose interfaces of the sensitivity operator, constructing update direction vectors, and generating a pre-projection parameter field; sequentially performing box-constrained projection, total variation projection, and wavelet sparse projection on the pre-projection parameter field to obtain a sparse parameter field and generate the final parameter field; generating a 3D grade voxel array, calculating the grade segmentation threshold, extracting the orebody connected body set, generating a orebody triangular grid and an orebody existence probability voxel array, and obtaining a digital twin base data package. This method shortens computation time, reduces storage pressure, and improves the accuracy and practicality of the inversion.

The invention discloses a curved surface flattening method and system for inhibiting size distortion of a specific area, a medium, equipment and a product in the technical field of computer graphics. The method comprises the following steps: rasterizing a narrow-band region A of a curved surface p1 to obtain 2 (k-1) triangular grids; fitting a space curve S1 according to the centroid coordinate points of all the triangular grids, uniformly sampling N points on the space curve S1, and vertically projecting each point to the triangular grid closest to the point as a projection point of the triangular grid; traversing all the triangular grids, and obtaining a mapping point set of the triangular grids according to projection points, closest to the specified end of the narrow-band region A, on the triangular grids; and sequentially rotating each triangular grid and the mapping point set thereof as a whole by utilizing a spatial transformation method under the condition of keeping the common edge and the common vertex of every two adjacent triangular grids coincide, keeping the normal vector directions of all the triangular grids after rotation to be the same, and completing curved surface flattening.

The invention discloses a self-shielding coil design method based on a finite element method, relates to the technical field of high-precision magnetic field control, and solves the problems that when a compensation coil is designed in a closed magnetic shielding structure (such as a permalloy cylinder), the external stray magnetic field of the coil is coupled with the wall of the magnetic shielding cylinder to induce eddy current, so that the compensation magnetic field is distorted, and the background noise is increased. Meanwhile, high-precision magnetic field generation of a target area needs to be realized in a limited space. According to the technical scheme, finite element triangular mesh discretization is carried out on the surfaces of a main coil and a shielding coil; constructing a target function; and solving the minimum value of the function to obtain the optimal solution of the flow function psi of all grid nodes, calculating the current density of each triangular grid unit according to the optimal solution, and finally generating a closed-loop wire wiring structure of the main coil and the shielding coil along an equal-flow function line. The method is mainly used for scenes, such as a biological magnetic measurement system, magnetic resonance imaging and the like, which are limited in space and need to suppress external magnetic field coupling, and collaborative optimization of a high-precision target magnetic field and active self-shielding is realized.

The application discloses a kind of degenerative farmland soil organic matter three-dimensional mapping methods of fusing remote sensing, near-ground sensing and historical data, it is related to digital soil mapping technical field, the method is based on INLA-SPDE three-dimensional model framework, fusing remote sensing, near-ground sensing and historical data realizes high-precision three-dimensional mapping, steps are as follows: collecting soil profile different depth organic matter data and near-sensing visible near-infrared reflectance spectrum data in each sampling point of study area, then screening and organic matter significantly related visible near-infrared reflectance spectrum characteristic band, collect and integrate historical data, and complete standardization processing to remote sensing, near-ground sensing data;Divide modeling set and verification set, determine the triangular grid parameter based on semi-variogram and construct SPDE model;Near-sensing, remote sensing data are used as covariant and are incorporated into INLA-SPDE three-dimensional model, generate soil organic matter three-dimensional spatial distribution map after model fitting and quantify uncertainty.The application overcomes the problem that traditional method cannot accurately simulate the vertical variation of soil properties, realizes the high-precision, high-efficiency three-dimensional mapping of regional scale soil organic matter in horizontal and vertical dimensions.