70 results about "Triangulated irregular network" patented technology

Method includes calculating a mean z coordinate value for points within the point cloud. An initial set of points is selected which have z coordinate values which deviate from the mean by at least an initial value. Thereafter, a triangulated irregular network (TIN) is constructed using the initial set of points. The method continues by determining if there is a significant point that exists among the points contained within an x, y extent of each triangle. If so, the TIN is updated to include the initial set of points and any significant points determined to exist within the triangles that form the TIN. Thereafter, the method continues by repeating the determining and the updating steps until there are no additional significant points found within the triangles.

The invention discloses an intelligent filtering method for airborne laser point cloud data. The method comprises the following steps of: reading laser point cloud data to ensure that points contained in laser point cloud data of a grid index organization generate one dense point cloud grid and a sparse point cloud grid; classifying the sparse point cloud grid to obtain an urban area and a mountain area; dividing the urban area and the maintain area by using different windows respectively to extract the local lowest point of each window; extracting to obtain an initial ground point by using the local lowest point as a seed point by area growing-based intelligent division; and establishing a triangulated irregular network (TIN) model according to the initial ground point so as to progressively encrypting the TIN model and iteratively extract ground points. In the processing process, manual intervention is not required, the interference of noise points can be effectively avoided, and the processing efficiency and filtering accuracy of the airborne laser-point cloud data can be improved. The excellent intelligent filtering method for the airborne laser-point cloud data can be widely applied to surveying and mapping industry.

A method, apparatus, and article of manufacture provide the ability to produce a smooth triangulated irregular network (TIN) surface. A TIN surface is obtained in a drawing on a GIS / CAD application. Thereafter, a surface smoothing technique is selected, such as Kriging or natural neighbor interpolation (NNI). Once interpolation output parameters are specified, additional surface points are interpolated in accordance with the selected surface smoothing technique and interpolation output parameters. The interpolated points may then be used to smooth the TIN surface.

The invention discloses a method for filling an isoline of a petroleum seismotectonic map, wherein the isoline of the petroleum seismotectonic map is built by using cross-sectional data after analysis and interpretation of seism and by using a triangulated irregular network. The method comprises the following steps: creating the isoline of the petroleum seismotectonic map by a common method of generating the isoline by using grids, building the triangulated irregular network by the Delaunay triangle principle, extracting a skeleton line, traversing a triangle by taking a line segment between every two points on the isoline as a restriction, extracting and deleting all the triangles intersecting with the line segment, locally rebuilding the triangulated network, and directly filling each triangle at equal intervals or gradually to generate the seismotectonic map. The method can fill an area between two optional isolines by filling each triangle, and has the advantages of high speed and precision when compared with the traditional coverage type filling method.

The invention relates to a design method of a three-dimensional simulation system for mining, which overcomes the defects that a three-dimensional simulation technology is low in quality, precision and intelligent mapping degree in the mining process. The design method comprises the following steps of: manufacturing an earth surface entity by a topographic mapping method using a rotary mating TIN (Triangulated Irregular Network) and distance and included angle biweight interpolation method; manufacturing a geological map of a surveying area by a geological surveying method of directly manufacturing a geological surveying result plan and an elevation by a disclination maneuvering network non-section method; synthesizing a three-dimensional visual model of mining geology; performing stripping design on a strip mine, or design on shaft building, advancement and exploitation of an underground mine, obtaining the position and direction of an intersecting line of two flats of broken mines (rocks) at a fault according to original geological data in shaft building, excavation or stripping, and adding the position and direction to the three-dimensional visual dynamic model, a sinking and driving engineering layout plan and a mine (rock) stratum (body) seam floor contour (isopach) map for mining geology and exploitation engineering; and establishing a mining geology and exploitation management module.

The invention discloses a geological interface three-dimensional morphological analysis method based on TIN (triangulated irregular network), which comprises the following steps: based on the use of a three-dimensional TIN model to simulate the geological interface, using the principles of space geometry and computer graphics to calculate general geometrical morphology parameters (gradient, angle and the like) and distance fields of the geological interface; using space interpolation and trend residual analysis technology to extract the morphology trend and fluctuation of the geological interface in a grading way; and finally applying a geological interface three-dimensional morphological analysis result to the simulation of ore-controlled geological factor fields and the concealed ore body forecasting. The method can precisely and efficiently analyze and extract all morphology parameters of the geological interface and expresses ore-controlled geological factors quantificationally and has significance in concealed ore body three-dimensional quantitative forecasting.

The invention discloses an arc scanning type construction scheme of a triangular irregular network containing edge topological information and relates to a technology for constructing the triangular irregular network (TIN) which is required for data processing of a geographical information system (GIS) and a laser radar (LiDAR), in particular to a fast construction technology of the triangular irregular network containing the edge information. In the scheme, a data structure containing directed edges and a topological relation thereof is used. The scheme comprises the following steps: firstly calculating distances and azimuth angles of all points in a point set relative to a certain selected reference center, sequencing the point set according to the distances to the reference center, joining discrete points into the triangular network one by one through the circular arc scanning way from inside to outside according to the sequence, and simultaneously performing local optimization on a newly generated triangle through the recursion way. In the method, a double circular linked list is combined with a storage bucket which is divided according to the azimuth angles for managing and retrieving all the edges on a convex border on the outer side of the existing triangular network. When each point is jointed into the triangular network, the guide function of the storage bucket is utilized for fast finding out the edges being in line with the networking conditions so as to construct the new triangle. The method has the characteristics of fast network construction speed, simple concept, easiness in realization and clear topological relation of the triangular network, thereby providing the effective method for constructing the triangular irregular network and performing the data processing thereof based on massive data of the LiDAR.

The invention discloses a large endangered wildlife monitoring method based on unmanned plane technology, and the method is as follows: first, a large endangered wildlife urgently to be studied in a natural protection area is selected, and a gathering area of the large endangered wildlife is determined; then a suitable unmanned plane landing area is selected by field survey, an aerial photography range is delimited, and an air route is formulated by the principle of the maximum of the aerial photography area; latitude and longitude and altitude data recorded by an airborne GPS (global position system) is transferred into a triangulated irregular network (TIN) for combining with aerial photographs to restore the real scene of an aerial photography area so as to obtain the altitude, trajectory, species composition and quantity for living of the large endangered wildlife. The method can realize the real-time large endangered wildlife monitoring and better understanding of large endangered wildlife living habits so as to improve the efficiency of large endangered wildlife protection and further promote the unmanned plane technology in the application of the large endangered wildlife protection field.

The embodiment of the invention provides a three-dimensional geographic scene model construction method and device based on a stereoscopic remote sensing image. The method comprises the following steps: carrying out image preprocessing on an original satellite remote sensing image, and acquiring a digital elevation model image and a digital orthoimage; conducting slicing according to a preset image slicing rule to obtain a digital elevation model image tile and a digital orthoimage tile; establishing a three-dimensional terrain model by using a triangulated irregular network construction technology, and mapping landform texture to the three-dimensional terrain model based on a texture coordinate mapping technology to obtain a partitioned three-dimensional geographic scene model; and finally, storing the partitioned three-dimensional geographic scene model according to tile row and column numbers to obtain a three-dimensional geographic scene model corresponding to the original three-dimensional satellite remote sensing image. Compared with a traditional modeling method, the technical scheme of the invention has the advantages of large modeling scale, high efficiency and high automation degree, and greatly improves the model construction efficiency and the like while ensuring modeling precision and the sense of reality.

The invention provides an unmanned aerial vehicle aerial photography image automatic generating line drawing method based on a desert area. The method comprises the following steps: designing a flightroute of an unmanned aerial vehicle; arranging an automatic identification type image control point or an automatic identification type target in a measuring area; an unmanned aerial vehicle carriedcamera or radar flying and acquiring images according to a preset airline; importing the images into aerial triangulation software to carry out aerial triangulation, and generating an LAS data file; importing the LAS data file into point cloud processing software to carry out point cloud processing and generating a TIN (Triangulated Irregular Network); performing point cloud resampling on the TINaccording to a mapping scale, editing a resampled terrain point, and importing the edited data into topographic map mapping software to automatically carry out contour line drawing and generating measuring area line drawing. According to the method in the invention, the unmanned aerial vehicle is used for measuring a target area, after the images are spliced, the method is not performed accordingto the traditional unmanned aerial vehicle mapping process, the cloud data processing flow is combined to directly generate the images into point cloud, the point cloud is resampled, an elevation point is plotted so as to manufacture a DLG (Digital Line Graphic), the precision is higher, and the efficiency is higher.

Method includes calculating a mean z coordinate value for points within the point cloud. An initial set of points is selected which have z coordinate values which deviate from the mean by at least an initial value. Thereafter, a triangulated irregular network (TIN) is constructed using the initial set of points. The method continues by determining if there is a significant point that exists among the points contained within an x, y extent of each triangle. If so, the TIN is updated to include the initial set of points and any significant points determined to exist within the triangles that form the TIN. Thereafter, the method continues by repeating the determining and the updating steps until there are no additional significant points found within the triangles.

The invention relates to a mean elevation plane triangulated irregular network-based topographic map elevation sparsing algorithm. The sparsing algorithm comprises the following steps of constructinga triangulated irregular network; obtaining a mean elevation plane; setting a threshold; reconstructing the triangulated irregular network; calculating an elevation gradient; screening feature elevation points; obtaining an extreme value of the elevation points; setting a height difference and a distance threshold; and deleting the triangulated irregular network, wherein the triangulated irregularnetwork (TIN) refers to the triangulated irregular network generated by adopting a Delaunay triangulated network. According to the triangulated irregular network-based topographic map elevation pointsparsing algorithm, the elevation points capable of remarkably reflecting topographic relief change are reserved as far as possible, and the topographic change in a sparsing range is better expressed; the elevation points can be averagely distributed in a map, and the local topographic relief condition with remarkable and tiny height difference change is better reflected; and by utilizing methodsof the mean elevation plane, the elevation gradient and the like, the elevation points are screened and sparsed to achieve a reasonable topographic map downsizing effect.

In order to obtain high-quality Digital Orthophoto Map (DOM), consistency processing of colors between images in the production process of the DOM is an indispensable technical link. In order to simplify a color processing step and further optimize an image uniform light and color effect, the invention discloses a consistency processing technology of colors between orthoimages on the basis of Triangulated Irregular Network (TIN). According to the technology, on the basis of image light-uniforming processing, through combinations with a mosaic line and an image after light uniforming, a target gray average and a variance of images are interpolated on the basis of the TIN, and then color consistency between the images is achieved by utilizing a Wallis conversion. Through a lot of experiments, an algorithm can obtain an ideal color consistency processing effect, extra overlap area color consistency processing are not needed after light- and color-uniforming processing; and the color consistency processing step is simplified, the whole processing does not rely on an external reference image, and the automatic degree of the color consistence processing is further improved.

The invention provides a creating device of a petroleum seismic structural map. The device creates isolines of the petroleum seismic structural map according to the profile data of seismic information, a triangulated irregular network is established according to the discrete data of the isolines, the position relation between adjacent isolines of the isolines is acquired and a point to be inserted is positioned in a triangle of the triangulated irregular network according to the topological structure of the triangulated irregular network; any two of three peaks beside the common point of three adjacent triangles of the triangle in which the point to be inserted is positioned are selected to be combined with the common point, and a quadric surface passing by the common point is acquired by the following formula: f (x, y) = a + bx + cy + dx2 + ey2, wherein a, b, c, d and e are natural numbers, and (x, y) is the coordinate of the common point; then accumulation average operation is carried out on the plurality of acquired quadric surfaces so as to obtain a quadric surface trend surface passing by the common point; and then the change of the area between adjacent isolines is restrained according to the quadric surface trend surface and the empty circumcircle property and the maximum and minimum angle properties of the triangulated irregular network.

The invention provides a terrain multi-scale TIN (Triangulated Irregular Network) online visualization method oriented to the virtual earth. The method comprises the following steps of global multi-scale TIN scale parameter mathematical model construction, terrain multi-scale TIN automatic construction and virtual segmentation under characteristic constraints, the online visualization of a multi-scale TIN topography spherical surface and real-time crack elimination, wherein the step of the terrain multi-scale TIN automatic construction and virtual segmentation under characteristic constraintsis realized as follows; the step of the online visualization of the multi-scale TIN topography spherical surface comprises the step of carrying out calculation to obtain visual terrain blocks of different levels according to point-of-sight information; and the step of the real-time crack elimination comprises the following step of carrying out quick decoding during real-time visualization to finish the edge connection of the adjacent boundary of terrain blocks of different levels. By use of the method, while the structural flexibility of the TIN is kept, the multi-scale irregular modeling andthe quadtree segmentation of a large-scale terrain are realized, meanwhile, the seamless real-time rendering of a mixed scale TIN terrain is supported, the terrain data processing and expression accuracy of the virtual earth can be greatly improved, a seamless fusion ability for irregular GF spatial data is also greatly improved, so that the high-fidelity expression requirement of a geographical environment can be met, and each category of reliable geographical analysis application can be supported.

The invention discloses a multiresolution multilayer successive point adding LiDAR (Light Detection and Ranging) filtering algorithm. The algorithm comprises the steps of three-layer filtering: in an initial layer: selecting part of ground points as seed points by virtue of a local minimum method, constructing a DEM (Digital Elevation Model) with certain resolution by virtue of a multi-surface function interpolation algorithm, re-calculating the elevation difference between each sampling point and a corresponding DEM net point, labeling the point with the elevation difference less than an initial set threshold as the ground point, repeating the process till no sampling point is divided into the ground point; in the filtering of a second layer and a third layer: doubling the resolution of the DEM based on the anterior layer, increasing a corresponding residual error threshold, repeating the calculation process of the anterior layer till no sampling point is labeled as the ground point, stopping iteration, and outputting ground point data. The average calculation accuracy of the algorithm is slightly higher than that of a self-adapting TIN (Triangulated Irregular Network) algorithm, much higher than those of seven filtering algorithms developed before 2004, and higher than those of nonparametric successive filtering algorithms and the like developed in recent years.

The invention discloses a catchment area dividing method based on a triangle patch, which comprises: 1) a confluence path extracting method based on a plane-point-side-point confluence mode that water of the triangle patch converges at the lowest point and then converges at the maximum side along slope; 2) a dividing method for marking a first-level catchment area of an upstream triangle based on the plane-point-side-point confluence mode; and 3) a multi-level catchment area dividing method for filling low-lying vertex in the catchment area based on the elevation of a catchment area water outlet. The catchment area dividing method based on the triangle patch can be applied to basin characteristic analysis of confluence path extraction, catchment area (multi-level) division and water outlet judgment of digital earth surface (comprising complex earth surface based on CD-triangulated irregular network (CD-TIN)) represented by the TIN, provides a new method for TIN-based digital elevation model (DEM) basin characteristic analysis, and can develop the corresponding software for the digital hydrological field (applied to urban waterlogging flood process simulation and simulated analysis).

The invention relates to a light detection and ranging (LiDAR) point cloud filtering method, in particular to a progressive triangulated irregular network point cloud filtering method based on voxel, which is applicable to airborne and ground-based radar point cloud data processing and belongs to the technical field of LiDAR point cloud data processing. The method comprises the following steps: loading LiDAR point cloud data; preprocessing the LiDAR point cloud data, and organizing and managing the point cloud data in a segmented way; determining a mathematical expression of LiDAR point cloud voxelization, and voxelizing point cloud; determining LiDAR point cloud multi-echo information, and retaining single echo and the last echo point in multiple echo; determining a mathematical expression of a LiDAR point cloud progressive triangulated irregular network, and filtering point cloud; and determining LiDAR point cloud multi-echo information, and retaining single echo and the last echo point in multiple echo. The method of the invention is applicable to complex terrain surfaces, is sensitive to detection of dense vegetation areas, steep slopes and irregular fracture zones, and can be used to generate a high-precision digital elevation model (DEM).

A navigation system has a database which stores index data for, respectively, a tile of a tiling. The index data includes, for each one of plural cells of a grid which is superimposed on the tile, respectively an identifier for each triangular face of a triangulated irregular network which at least partially overlaps with the respective cell. The plural cells of the grid are defined so as to cover the respective tile. A processing device of the navigation system is configured to use the index data to determine a triangular face on which a map feature having given lateral coordinates is located, in order to determine a height coordinate of the map feature.

The invention relates to the field of digital cartography technology, in particular to a threshold-irrelative point cloud filtering method and device for an airborne laser radar. The technical scheme comprises the following steps: 1) segmenting point cloud data and constructing triangulated irregular network (TIN) of the initial ground; 2) generating point cloud-ground altitude difference data; and 3) conducting filter processing based on the statistics of point cloud-ground altitude difference. The threshold-irrelative point cloud filtering method and device has the beneficial effects that by utilizing the integral statistical characteristics, the method and device is not necessary to adopt thresholds directly related to geometric characteristics of the point cloud data such as the altitude difference and slope to realize airborne Lidar point cloud data filtering process, so that the manual intervention of the whole filtering data processing course is reduced, and the working efficiency of the whole airborne Lidar point cloud data processing is improved.

The invention provides a multi-granularity calculation method for hybrid scene airborne laser point cloud classification. The multi-granularity calculation method comprises the following steps: selecting a classification neighborhood point set and a scene neighborhood point set by taking a sampling point as a center; training a point cloud global feature extraction model in an unsupervised learning mode to realize coarse-grained scene perception; a feature fusion strategy based on an attention mechanism is adopted, space context information is embedded in a point cloud semantic segmentation model, a multi-task loss function considering the terrain clearance and the category is defined, the category and the terrain clearance of each point in a classified neighborhood point set are supervised, and fine-grained point cloud semantic segmentation and terrain clearance prediction are achieved; through point cloud segmentation based on graph cut optimization and iterative adsorption of a ground triangulated irregular network, fine-grained ground classification result refinement is realized. According to the method, the classification problem of the mixed scene point clouds is decomposed into a combination of three relatively single problems, the complexity of the whole problem is effectively reduced, and robust and fine classification of the point clouds of different complex scenes can be realized.

A navigation device for a vehicle comprises a database storing, for a plurality of tiles of a tiling, at least one triangulated irregular network (TIN) defining a three-dimensional surface, and, for a plurality of triangular faces of the at least one TIN, control information defining a nested bounding sphere for the respective triangular faces. The navigation device comprises a processor coupled to the database configured to calculate a screen-space error for the plurality of triangular faces based on the respective control information and based on at least one of the following: a viewing angle of an electronic map view, a virtual camera position of the electronic map view. The processor is configured to predict whether a triangular face is visible in the electronic map view based on the calculated screen-space error.

The invention discloses a method for accurately calculating morphology change of a gully head and a gully wall of a gully with a washing hole. The method comprises the following steps of: firstly, importing the determined gully terrain grid data into GIS (Geographic Information System) software and setting a coordinate projection system; secondly, cutting the terrain data of the gully into three parts according to a water collecting area, a gully wall and a gully bed boundary; importing terrain data of the gully wall into a file which can execute data operation and respectively rotating spatial coordinates around a Z axis and an X axis according to the certain angle; secondarily importing the rotated gully wall data into the GIS software and extracting a boundary point position of the gully wall in a GIS software environment to generate a face file; then generating TIN (Triangulated Irregular Network) by using the rotated space point position and the boundary file; converting the TIN into a DEM (Digital Elevation Model) with proper size of grids; and subtracting the DEMs at different stages to finally obtain the terrain change processes of different stages. The method disclosed by the invention can be used for generating the DEM accurately and quickly, is simple in operation and does not need complex three-dimensional space conversion operation.

The invention discloses a multi-scale triangulated irregular network (TIN) library coupled storage method, which comprises the following steps of: preprocessing multi-scale data, namely comparing and replacing points and reducing the data storage capacity; encoding points and edges so as to provide information during multi-scale display; and finally performing associated storage on the multi-scale points and edges. The method supports one-off joint update of a multi-scale TIN digital elevation model (DEM) net based on characteristic points, lines and planes, the production efficiency of the DEM is improved, the storage space is saved, the effective utilization rate of space is improved, and great convenience is provided for three-dimensional multilevel visualization of the multi-scale TINDEM net due to TIN DEM net association.

The invention provides a cone structure characteristic parameter detection method based on a point cloud data processing technology. Firstly, high-precision scanning is carried out on the cone in three-dimensional space, the point cloud data are acquired, and a Delaunay grid partitioning method is used to build a TIN (Triangulated Irregular Network) grid model for the obtained point cloud data of the cone; then, the least square fitting method is used to calculate each point in the nearest neighborhood point set of each space point in the point cloud data of the cone, and the nearest neighborhood plane normal vector of each space point in the point cloud data of the cone is acquired; a distribution law of the nearest neighborhood plane normal vector of each space point in the point cloud data of the cone in normal vector space is further acquired; and then, whether a tested model is a cone model is judged, and if yes, the tested model is extracted, that is, the cone structure characteristic parameters comprising a cone angle, a cone height and a bottom radius are extracted.

A navigation device for a vehicle comprises a database storing, for a plurality of tiles of a tiling, at least one triangulated irregular network (TIN) defining a three-dimensional surface, and, for a plurality of triangular faces of the at least one TIN, control information defining a nested bounding sphere for the respective triangular faces. The navigation device comprises a processor coupled to the database configured to calculate a screen-space error for the plurality of triangular faces based on the respective control information and based on at least one of the following: a viewing angle of an electronic map view, a virtual camera position of the electronic map view. The processor is configured to predict whether a triangular face is visible in the electronic map view based on the calculated screen-space error.

The invention relates to a ball, cylinder and elliptic cone model recognition method based on a point cloud data processing technology. The method comprises the following steps: a high-precision three-dimensional scanner is used to scan ball, cylinder and elliptic cone models and point cloud data of the ball, cylinder and elliptic cone models are acquired; a Delaunay grid partitioning method is used to process the acquired point cloud data of the ball, cylinder and elliptic cone models, and thus, a TIN (Triangulated Irregular Network) grid model for the point cloud data of the ball, cylinder and elliptic cone models is acquired; and a least square fitting method is used to calculate each point in the nearest neighborhood point set of each space point on the TIN grid model for the acquired ball, cylinder and elliptic cone models, and thus, a distribution law of a nearest neighborhood plane normal vector of each space point in the acquired point cloud data of the ball, cylinder and elliptic cone models in normal vector space is further acquired.

The invention provides a three-dimensional complex modeling method utilizing a rotating TIN (triangulated irregular network) and a distance and included angle dual-weight interpolation method, and relates to a three-dimensional modeling method. The shortcomings that dispersibility and alternativity among data in a data structure of an existing three-dimensional complex modeling method are insufficient, echo matched degree is also insufficient, and influence of an include angle between each two adjacent triangular planes formed by adjacent data is not directly considered in an existing algorithm are overcome. The three-dimensional complex modeling method comprises the following steps of arranging sampling points at joints of the rotating network; adjusting a certain sampling point to a new position if the sampling point in the rotating TIN can be used as a feature point of a modeling body after the sampling point is adjusted within a range , which is centered at the sampling point, of 0.15 times of the side length of a basic square; adding other feature points according to features of the modeling body; connecting each added feature point with three vertexes of a triangle with the feature point to form a local secondary encryption network; performing feature value interpolation by utilizing the distance and included angle dual-weight interpolation method; making contour lines; and making a three-dimensional perspective drawing of the modeling body.

Disclosed is a polygonal image digitizing method utilizing a rotating TIN (triangulated irregular network). The polygonal image digitizing method aims to overcome the shortcoming that echoes and matching of existing pixels are insufficient. The polygonal image digitizing method comprises the following steps of determining the side length of a basic square according to a Shannon's sampling theorem; arranging one sampling point at each of four vertexes of the basic square, and arranging 3 sampling points in the basic square in a scattered manner to form a basic unit; counterclockwise rotating the basic unit to form a primary unit body, a secondary unit body and a tertiary unit body; splicing the basic unit, the primary unit body, the secondary unit body and the tertiary unit body to form a square assorted unit; utilizing the assorted unit as a replication unit, and performing translation replication repeatedly to form a sampling network covering an image; and utilizing control points in the sampling network as centers to relatively uniformly divide the area in the range of the sampling network into polygons by straight lines, utilizing the areas of the small polygons as sampling units, utilizing brightness values of feature points as brightness values of the sampling units when the feature points are arranged in the sampling units, and utilizing brightness values of the control points in the sampling units as brightness values of the sampling units so as to finish digitization of an image when the feature points are not arranged in the sampling units.