95 results about "Horizontal and vertical" patented technology

The invention discloses a landslide deformation mode recognition method based on InSAR multi-dimensional observation, and belongs to the technical field of geological disaster dynamic recognition and monitoring, in the method, a two-dimensional deformation decomposition formula can convert InSAR observation data of different incident angles into actual deformation rates of the earth surface in the horizontal direction and the vertical direction. By introducing topographic information and incident angle parameters, sight line displacement is converted into displacement in the horizontal direction and the vertical direction, so that the real deformation characteristics of the landslide are reflected more accurately, the thickness of a soil landslide mass is inverted by using a mass conservation equation, and the landslide form is obtained by combining the topographic information. The shape and distribution characteristics of the sliding surface can be further analyzed, and more comprehensive information is provided for landslide mode recognition. The landslide deformation mode can be judged more accurately by integrating the landslide shape and the two-dimensional displacement distribution characteristic inversion landslide mode, so that a more reliable basis is provided for landslide early warning and disaster prevention and control, and the landslide disaster risk is effectively reduced.

The invention discloses a method for scheduling the section position of a storage yard, and the method comprises the steps: building a two-dimensional geodetic coordinate system, and obtaining the node coordinates of each grid in different sites; establishing a corresponding site coordinate system for each site; calculating a center coordinate of each grid in a geodetic coordinate system; after the subsection is transported to the position near the designated position, whether the sizes of all grids in the site where the subsection is located are consistent or not is judged, if yes, the distance between the center coordinate of the subsection and the center coordinates of the surrounding grids under the geodetic coordinate system is calculated, and the subsection is transported to the closest grid; if not, converting the coordinates of the subsection and the grid in the site coordinate system into coordinates in the geodetic coordinate system, then comparing the relation between the center coordinate of the subsection and the node coordinates of each grid under the geodetic coordinate system, and if the horizontal and vertical coordinates of the subsection are located between the maximum value and the minimum value of the horizontal and vertical coordinates of the four-point coordinates of a certain grid, judging that the subsection is not consistent with the grid. And transporting to the grid section by section. The field utilization rate and the production efficiency can be improved.

The invention relates to the technical field of geotechnical engineering, in particular to a slip crack surface calculation method for a limited-width soil body in an active non-limit state. Comprising the following steps: step 1, determining a gradual exertion rule of a limited soil body internal friction angle and cohesion between the rigid gravity type retaining wall and an existing bedrock, a wall-soil external friction angle and wall-soil interface cohesion developing along with the displacement of the retaining wall, and establishing mathematical characterization of limited soil body non-limit state strength parameters developing along with the displacement of the retaining wall; step 2, establishing a relationship among the horizontal stress, the interlayer shear stress and the average vertical stress; step 3, establishing a balance equation of the rectangular area and the triangular area in the horizontal and vertical directions; 4, solving the slip crack surface inclination angle meeting the plastic upper limit theorem by adopting a numerical method; and 5, calculating the resultant force of the horizontal active soil pressure and the upsetting moment of the horizontal active soil pressure on the wall heel. The method provides a theoretical calculation basis for the design of the soil retaining structure under the working condition of the limited-width soil body.

The invention belongs to the technical field of ultra-precise angle measurement, and discloses a three-dimensional angle measurement device and method based on wavefront interference fringes. According to the invention, two wavefront interference light spots are generated by using two paths of detection laser in a single interference measuring head with only a single coordinate reference, the spatial frequencies of respective fringe images in the horizontal and vertical directions are respectively calculated, and simultaneous decoupling is carried out so as to accurately measure the pitching, deflection and rolling angle deviations of the reflector. According to the three-dimensional angle measurement device, point-to-point three-dimensional angle measurement can be achieved, the measurement resolution is high, the measurement result can be directly traced to the laser wavelength, and the requirement of high-end equipment for ultra-precise three-dimensional angle measurement is met.

The utility model discloses a cable strand steel wire positioning device. The positioning device consists of a frame body, a fixing piece and a shaft, the shaft consists of a vertical shaft and a transverse shaft; the vertical shaft and the transverse shaft are respectively fixed by a bearing seat and a bearing on the inner side of the frame body and are arranged in a self-rotating manner; a wire penetrating hole is formed between the vertical shaft and the transverse shaft. And the top edge and the side edge of the frame body are provided with corresponding horizontal and vertical coordinate marks corresponding to the threading holes. The horizontal coordinate and the vertical coordinate are arranged on the device, the steel wire penetrates through the device in a positioning mode according to a coordinate comparison table, the steel wire is prevented from being misplaced, twisted and abraded in operation when the main cable strand is manufactured, and the production efficiency and the product quality of the main cable strand are effectively improved.

The invention relates to the technical field of intelligent agriculture, and discloses an agricultural machinery driving track identification method based on deep learning, which comprises the following steps: step 1, extracting operation data from agricultural machinery intelligent equipment, and arranging all the data according to a time sequence to form a data source set C; 2, traversing the set C, extracting longitude and latitude data, recording the longitude and latitude data into a new set C1, and converting spherical coordinates into horizontal and vertical coordinates (x, y) in a rectangular plane coordinate system by using a Gaussian projection method to obtain a set C2; and step 3, adopting a DBSCAN density clustering algorithm to classify the set C2. The method depends on GPS latitude and longitude coordinate data, does not need to additionally use a high-precision sensor, then fundamentally reduces the dependence on hardware equipment, and compared with a scheme which highly depends on a sensor in the prior art, the method avoids errors caused by sensor damage and insufficient precision, improves the system stability, and reduces the agricultural production cost at the same time.

The invention discloses a 2D / 3D visual calibration plate for industrial manufacturing, which comprises a calibration plate body, a plurality of target patterns are arranged on the calibration plate body, the target patterns comprise circular patterns and / or square patterns, and the circular patterns are used for calculating an ellipse center point under imaging perspective deformation of an industrial robot camera; the checkered pattern comprises cross lines and digital labels and is used for calibrating the tail end of the industrial robot, and calibration comprises calculation of a coordinate transformation relation between a camera coordinate system and a robot coordinate system. According to the method, the calibration is more precise through the structural optimization of the calibration plate, the calibration process is simplified through the three-point method, the calculated amount is extremely small, the calibration precision and efficiency are remarkably improved, the coordinate axis orientation is assisted through the arrangement of the asymmetric pattern, the horizontal and vertical coordinate axes are judged through the assistance of the grid pattern, and the robustness is improved.

The invention relates to the technical field of geological survey and surveying and mapping, and discloses an inclination angle measurement auxiliary mechanism in surveying and mapping engineering and a measurement method.The mechanism comprises a mounting base and a load-bearing base, a drop hammer located in a hollow cavity of a telescopic connecting rod is arranged on the side, facing the load-bearing base, of the bottom of the mounting base, and a first emitter is arranged at the bottom of the drop hammer; a first detector is arranged in the center of the bearing base; at least three groups of pressure sensors are uniformly distributed in the hollow cavity of the telescopic connecting rod and are relatively positioned on the peripheral side of the drop hammer; a second emitter is arranged on the first rigid supporting rod, and second detectors are arranged at the positions, corresponding to the second emitter, of the second rigid supporting rod and the third rigid supporting rod; the inclination angle measurement auxiliary mechanism is used in cooperation with a geological compass, a surveying and mapping marker post or a geodetic surveying and mapping device, leveling in the horizontal direction and the vertical direction can be automatically achieved, a user does not need to manually operate in the inclination angle measurement process or do not need to subjectively feel to adjust the compass, the measurement workload is reduced, and the measurement precision is improved.

The invention discloses a navigation satellite signal coming direction simulation method based on a hybrid clustering algorithm. The navigation satellite signal coming direction simulation method comprises the steps that 1, satellite coordinate values in a geodetic coordinate system are calculated; 2, projecting to an east-north-sky coordinate system, and calculating the distance between any two satellites; 3, setting a cluster number, an azimuth angle threshold value and a distance threshold value; step 4, clustering is carried out by using a DBSCAN algorithm; 5, calculating horizontal and vertical coordinate values of the central point of each cluster; step 6, clustering each satellite point by using a K-means algorithm; step 7, determining an optimized clustering result; 8, judging whether the maximum value of the azimuth angle difference value is smaller than or equal to the azimuth angle threshold value or not, and if yes, entering the step 9; otherwise, updating and optimizing the clustering result by using a K-means algorithm, and returning to the step 8; and step 9, outputting a current optimization clustering result. According to the invention, the incident angle difference between the false satellite signal and the real satellite signal can be significantly reduced, the state of the navigation satellite can be simulated more truly, and the possibility of identifying the false satellite signal is reduced.

The invention relates to an aircraft flight path planning method based on inertial navigation, and the method comprises the steps: obtaining the coordinates of M route points on the total flight path of an aircraft, the total flight path of the aircraft comprises the flight path of M + 1 segments, and each segment is provided with a plurality of sub-segments; constructing an independent variable of a target function according to an item representing a remaining voyage corresponding to a point on the track of the segment, an item representing a remaining voyage corresponding to a starting end point of the track of the target segment, and an item representing a remaining voyage corresponding to an ending end point of the track of the target segment; constructing the target function according to the independent variable of the target function, the item representing the coefficient of the segment and the item representing the primary function; according to the coordinates of the M waypoints, based on the inter-segment transition condition of the objective function, solving a total coefficient set including the coefficient set of each segment; and according to the objective function and the total coefficient set, determining a horizontal and vertical coordinate corresponding relation set of each segment so as to determine the track of each segment.

The invention relates to the technical field of data processing, in particular to a method for determining a maximum information coefficient and a method for judging data relevancy, which comprises the following steps of: in an X-axis direction, taking two sections with a being equal to 2 to divide Q in equal depth; arranging the scatter points in a descending order in the Y-axis direction, connecting the scatter points into a scatter line, taking an intersection point of the scatter line and the division line in the X-axis direction as a division point in the Y-axis direction, and taking a corresponding value in the Y-axis direction as the division P in the Y-axis direction; solving a maximum mutual information value; calculating a feature matrix MX (D) under X-axial isometric division; interchanging horizontal and vertical coordinates, and repeating the steps to form a characteristic matrix MY (D) of Y-axis equal-depth division; and taking the maximum element in the feature matrix MX (D) and the feature matrix MY (D) as the final maximum information coefficient value of the two variables. By means of the determination method and the data relevancy judgment method, the calculation amount of the maximum information coefficient solving process can be reduced.

The application discloses a metal detection method for real-time correction of product state, comprising: collecting a detection point set of a measured product when the product passes through a probe and calculating a geometric center; extracting a main feature vector and a secondary feature vector orthogonal to the main feature vector based on an Euclidean distance; rotating and aligning in the direction of the main vector and extracting main / secondary direction components after rotation, taking the components and an angle between the main vector as features for recording and caching; calculating an effective average rotation angle and horizontal and vertical judgment thresholds based on a number of qualified records in the cache; translating the point set of a product to be measured and rotating to an aligned coordinate system according to the effective average angle, and comparing the point set after rotation with the effective threshold to determine whether the product is qualified or not. The method realizes online adaptive updating of the threshold based on the nearest qualified sample, can correct in real time under the condition of no shutdown along with the slow change of the product state, reduces false positives and maintains detection sensitivity.

The present invention relates to the technical field of ship navigation operations, and provides a three-dimensional route monitoring method and system. The method includes determining the current segment based on the horizontal and vertical distances between two waypoints in the segment; calculating the horizontal deviation distance and the intersection point of the underwater vehicle and the current segment, and calculating the depth deviation distance and the three-dimensional deviation distance based on the intersection point; detecting whether there is an obstacle hazard using a fan-shaped detection azimuth interval method; obtaining the current water depth based on grid terrain data or nautical chart data, and calculating the true water depth based on tidal data and the current water depth; calculating the depth of the underwater vehicle from the water bottom based on the true water depth, and detecting whether there is a depth hazard based on the depth from the water bottom. The present invention solves the problem that traditional two-dimensional segment judgment cannot adapt to the three-dimensional underwater environment. It enables the vehicle to accurately identify the current segment even in complex sea conditions, grasp the true water depth of the current position in real time, effectively avoid dangers such as collisions with submarine mountains, and improve the safety of deep-sea navigation.

The invention relates to the technical field of numerical control, and discloses a digital twin numerical control platform of paving equipment. According to the invention, the chute bottom plate is used as a bottom plate part of the chute track, and the guide groove plate, the sliding insertion shaft and the bearing base which are connected with the side surface of the chute bottom plate together form a motion assembly for driving detection scanning. A lifting assembly formed by the lifting device shell, the lifting motor, the threaded shaft, the traction sleeve and the connecting rod together is used for driving the scanning head to move up and down and on the horizontal plane. By means of the frame structure formed by the components, an operator can input the terrain used for scanning and completing modeling on a certain basis, data errors caused by manual operation and preliminary screening and leveling of data in the horizontal direction and the vertical direction are avoided, and modeling is greatly facilitated.

The invention provides a detection mechanism installation and adjustment method applied to PCB blind hole detection. An existing scanning camera is installed on a detection rack in advance, then a detection strip is detected through the linear array scanning camera to form a detection image of the detection strip, and the detection image is compared with a preset image of the detection strip to determine the horizontal deviation angle of the linear array scanning camera. The horizontal angle of the linear array scanning camera is adjusted according to the horizontal deviation angle of the linear array scanning camera, so that the linear array scanning camera is parallel to the horizontal direction of the horizontal plane, and then the vertical deviation angle of the linear array scanning camera is determined according to the included angle between the shooting point of the linear array scanning camera and the point where the actual axis is located. Therefore, the linear array scanning camera is ensured to be perpendicular to the detection plane, the angle micro-adjustment of the linear array scanning camera in the horizontal direction and the vertical direction can be conveniently realized, the linear array scanning camera is ensured to be reliably mounted in the horizontal plane, and the accuracy of subsequent testing is ensured.

The utility model provides a test device for simulating connection channel pipe-jacking method construction, the test device comprises a model box, a main tunnel model and a connection channel model, the main tunnel model is arranged in the model box, one side of the main tunnel model is provided with a through hole, the connection channel model is located in the main tunnel model, and the through hole is arranged in the connection channel model. A soil body is filled between the interior of the model box and the main tunnel model; a supporting device, a pushing device and a detection device are arranged in the main tunnel model, the supporting device is used for applying pre-supporting force to the pipe wall of the main tunnel model in the horizontal direction and the vertical direction, one end of the pushing device is connected with the supporting device, and the other end of the pushing device is used for pushing the connection channel model to enter the soil body through the through hole; the detection device is used for detecting strain and stress of the main tunnel model in real time. According to the utility model, actual construction conditions can be simulated, and the influence of different jacking forces and pre-supporting forces on the main tunnel structure can be researched.

The invention relates to the technical field of intelligent driving, and discloses a map lane line transverse and longitudinal error evaluation method, which comprises the following steps: S10, obtaining lane line data of a true-value lane line L1 and a to-be-measured lane line L2, the lane line data comprising geographic positions; s20, carrying out equidistant data point acquisition on the L2; s30, the true value lane line L1KD-tree is subjected to structuring, and the true value lane line L1KD-tree is obtained; s40, calculating the point-to-broken line distance from the midpoint of L2 to L1, and normalizing the distance according to the number of m points to obtain a final result d (L1, L2), the formula being # imgabs0 #, m being the sampling number of L1, p being a two-dimensional space point expressed by horizontal and vertical coordinates, and d (L1, L2) being the distance between L1 and L2; the final result d (L1, L2) is a transverse and longitudinal absolute error of L2 relative to L1.

The present invention discloses a coordinate compensation method for non-centered reference point components in AOI automatic programming, which includes the following steps: determining non-centered reference point components in the PCBA that require coordinate compensation; calculating the horizontal and vertical coordinate compensation values of the non-centered reference point components; using the compensation values to calculate the horizontal and vertical coordinates of the geometric center of the non-centered reference point components; updating the coordinates of the non-centered reference point components in the PCBA with the geometric center coordinates, and using this data as input to carry out automatic programming of the automatic optical inspection instrument and inspection of the PCBA. The present invention solves the problem that the inspection frame of the non-centered reference point component is offset from the physical assembly position.

This invention discloses a method for evaluating the quality of marine controlled-source electromagnetic data, belonging to the field of data quality evaluation technology. The method includes: projecting the acquired marine controlled-source electromagnetic data onto a two-dimensional plane, whereby the real and imaginary parts of the data signal are projected onto the horizontal and vertical coordinates to obtain the data distribution; performing cluster statistics on the data distribution using the K-medoids clustering method to obtain cluster centers; and using the cohesion (CP) calculation formula to perform aggregation degree analysis on the data distributed according to the cluster centers to obtain the data quality assessment result. This invention can directly quantify and evaluate data based on the cohesion of the electromagnetic data distribution characteristics, without defining empirical functions, requiring no specific data volume, and is unaffected by fly-spot data, thus improving the applicability and accuracy of the evaluation method.

The invention discloses a surface topography detection probe device and method based on active deflection compensation, and the device comprises an up-down displacement measurement module which is used for carrying out the measurement of the vertical displacement of a contact probe through a split type multi-polar-plate capacitive sensor structure; the up-and-down force balance control module and the up-and-down displacement measurement module form a second closed-loop control system and are used for controlling the contact force between the contact pin and the surface of the sample to be constant; the front and back deflection measurement module is used for detecting the deflection amount of the contact pin in the scanning direction; the front-back deflection control correction module and the front-back deflection measurement module form a first closed-loop control system and are used for calculating required correction torque through a closed-loop control algorithm and applying reverse driving force to counteract deflection caused by shearing force, and the two closed-loop systems work cooperatively to control the probe in the horizontal direction and the vertical direction. The problems that when an existing probe scans a complex shape, a track deviates due to shearing force, and the signal-to-noise ratio of displacement measurement is insufficient are solved.

The invention discloses a virtual gift guiding method and system fusing AR navigation and LBS, particularly relates to the technical field of augmented reality, and is used for solving the problem that a user is difficult to position targets at different height levels due to lack of guidance in the vertical direction in a complex three-dimensional space in existing augmented reality navigation. Height data of a user and a target position are obtained and fused, a height difference is calculated, and the matching degree between the change trend of the height difference and the vertical motion intention of the user is analyzed, so that joint reasoning is intelligently triggered; further identifying a channel connected with a vertical layer, and evaluating the visual discoverability of the channel and the spatial cognitive state of the user; and finally, dynamically selecting a visual coding strategy based on an evaluation result, and generating and rendering a composite virtual guidance element which integrates horizontal and vertical direction guidance in an augmented reality interface, so that visual and accurate full-dimensional space navigation is realized.

The present invention proposes an optimization method for the inspection AUV model of a water conveyance tunnel. An applicable coordinate system is established according to the working environment, and then the six-degree-of-freedom motion equation of the AUV is established from the perspectives of rigid body and fluid force, and decomposed into horizontal and vertical plane motions to establish kinematic and dynamic models. The tunnel inspection AUV model is simplified. Finally, from the perspective of a new type of wing plate, computational fluid dynamics analysis is carried out according to the working conditions of the water conveyance tunnel, laying a foundation for energy consumption modeling, energy-saving operation planning, and energy-saving control.

This invention discloses an automatic finite element modeling method and system based on construction drawings. The method includes: automatically outputting unannotated construction drawings as annotated ones using a computer vision-based construction drawing recognition module; assigning horizontal and vertical axis numbers and 3D coordinate information to each building component on the annotated construction drawings using a grid dimension recognition module; automatically recognizing and fusing the dimensional information of each building component on the annotated construction drawings with their assigned horizontal and vertical axis numbers and 3D coordinate information using a large language model as an automatic modeling module; naming and assigning material properties to each building component in the 3D geometric model; and automatically creating a visualized finite element model based on the construction drawings by assigning support constraint information and load information to the 3D geometric model. This invention has the advantages of high modeling efficiency, high quality, and replacement of manual labor.

This invention discloses a coordinate transformation method for lane line recognition. Based on a high-quality image acquisition system and the analysis and derivation of the world coordinate transformation algorithm in lane line recognition, it further analyzes and derives the transformation method between the image coordinate system and the camera coordinate system regarding the horizontal and vertical coordinates, and points out existing problems and optimization directions in the coordinate transformation algorithm. To simplify the coordinate transformation calculation, a coordinate transformation method based on tanγ0 calibration is derived. Six methods for tanγ0 calibration are proposed, and the optimal method is selected for calibration. Substituting the tanγ0 calibration value into the transformation formula achieves the coordinate transformation function for lane line recognition. Finally, the transformation method is tested, and hardware installation suggestions for improving coordinate transformation accuracy are given, effectively improving the accuracy and real-time performance of coordinate transformation, thereby improving the accuracy of automatic lane line recognition.

The present application relates to the technical field of safety monitoring of water conservancy and hydropower projects, and in particular to an arch dam displacement monitoring device and method based on laser alignment and ranging, wherein the device comprises: a relative displacement measuring component for obtaining horizontal and vertical displacements perpendicular to a target direction between adjacent measuring points of a plurality of measuring points of the arch dam, and obtaining horizontal displacements along the target direction between adjacent measuring points; a displacement coordinate conversion component for converting the obtained horizontal and vertical displacements into relative horizontal and relative vertical displacements in a target coordinate system based on a preset geometric projection relationship; an arch dam displacement monitoring component for calculating the absolute three-dimensional displacement of each measuring point by stepwise superposition based on the relative horizontal and relative vertical displacements, and obtaining the actual displacement of the arch dam according to the absolute three-dimensional displacement of each measuring point. Thus, the present application solves the problems in the related art such as the need to build an observation room to protect the instrument, high implementation cost, and poor adaptability to the terrain on both sides of the dam.

The present invention provides a method for diagnosing the spatial stability of underwater structures based on three-dimensional through-scanning. The method comprises: S11, performing a bidirectional scan of the underwater structure to extract point cloud data; S12, generating a three-dimensional structure model based on the point cloud data to obtain the buried depth of the underwater structure; S13, obtaining the lateral settlement difference based on the buried depth of the underwater structure, and calculating the inclination angle between the horizontal axis of the underwater structure and the horizontal plane; S14, obtaining the longitudinal elevation deviation based on the buried depth of the underwater structure, and calculating the angle between the longitudinal axis of the underwater structure and the horizontal plane; S15, setting the intersection point of the horizontal and vertical tangents along the direction of the underwater structure as A, finding an arbitrary point on the horizontal tangent as B, and finding an arbitrary point on the vertical tangent as C, and given the coordinates of the three points, calculating the angle at point A; S16, comparing the angle at point A with a preset threshold to determine the stability of the underwater structure. The stability diagnosis method provided by the present invention improves the safety and service life of underwater structures.

A system is provided.SOLUTION: A system comprising means for collecting position information (latitude, longitude, and altitude) every hour from a plurality of base stations installed all over the country, means for comparing the collected position information with previous position information and calculating horizontal and vertical displacement of the ground, means for inputting the calculated displacement data of the ground to a generative AI model and analyzing correlation with past earthquake data to predict an earthquake, means for notifying a self-governing body or a weather forecast service provider of a prediction result, and means for storing the prediction result in a database and archiving it in an analyzable form later.SELECTED DRAWING: Figure 1

This invention relates to the field of pattern recognition technology, specifically to a method and system for identifying the state of porcelain insulators. The method includes the following steps: collecting pixel features from the surface of the porcelain insulator, screening and establishing a bright coordinate sequence, extracting a set of stripe center points, linearly fitting the horizontal and vertical coordinates to generate an ideal projection reference, comparing the deviation span with the damage boundary, locating surface defects, and obtaining the identification result. In this invention, by screening pixel features according to a set boundary to establish a bright coordinate sequence, integrating the sequence to extract a set of stripe center point coordinates, performing linear fitting on the horizontal and vertical coordinates of the center points to generate an ideal stripe projection reference, comparing the deviation span of each coordinate from the reference, and filtering out two-dimensional row and column coordinates exceeding the judgment limit, the comparison mechanism of directly constructing an ideal projection reference from the bright feature structure of the porcelain insulator effectively avoids external background interference and the drawbacks of overall texture averaging, enhancing the sensitivity of porcelain insulator state identification and achieving accurate location of the actual distribution of surface defects.

Provided is a method of calculating high-resolution three-dimensional wind numerical information considering detailed topographic information, the method performing, when the wind numerical data of the operational LDAPS model is calculated (S100), a downscaling process based on the detailed topographic information using the wind numerical data as an input data, wherein the downscaling process performs a preprocessing process of converting a coordinate system and interpolating horizontal and vertical numerical data (S200), performs a process of adjusting roughness lengths (S300), correcting heights (S400), and correcting a subgrid-scale terrain drag effect (S500) on the basis of the detailed topographic information, and finally generating data that has gone through each of the processes as high-resolution wind numerical data (S600).

The invention discloses a bare soil extraction method based on a remote sensing two-dimensional spectral index, and the method comprises the steps: taking SAVI and NDRGI as horizontal and vertical coordinates to construct a two-dimensional index scatter diagram of each agricultural area, adjusting the size of a confidence ellipse of each land coverage category, namely a confidence region, enabling the confidence ellipse of an impervious surface and the confidence ellipse of cultivated land in a bare soil period to intersect, and enabling the confidence ellipse of the impervious surface and the confidence ellipse of cultivated land in a bare soil period to intersect; therefore, extraction thresholds of different agricultural areas can be obtained, bare soil distribution of the different agricultural areas can be accurately extracted, and bare soil distribution of research areas constructed by the different agricultural areas can be accurately extracted.