A GB-SAR image three-dimensional registration and accuracy evaluation method and system

Abstract

The present invention relates to a GB-SAR image three-dimensional registration and accuracy evaluation method and system, which can automatically register GB-SAR images and three-dimensional terrain coordinates with high accuracy through mining three-dimensional point cloud data collection, rail control point measurement and coordinate compensation; rail control point and image coordinate encoding based on GB-SAR coordinate system and equipment parameters; projection transformation of three-dimensional point cloud coordinates based on azimuth and distance invariant features; four-parameter conversion calculation of GB-SAR coordinate system and mining coordinate system; implicit function three-dimensional coordinate interpolation based on two-dimensional equal azimuth and distance feature coordinates; three-dimensional visualization analysis of slope deformation and registration accuracy evaluation. The method and system can not only automatically register GB-SAR images and three-dimensional terrain coordinates with high accuracy, but also realize three-dimensional visualization analysis and registration accuracy evaluation of GB-SAR slope monitoring results.

Description

Technical Field

[0001] The invention relates to the technical field of slope engineering deformation monitoring, and in particular to a GB-SAR image three-dimensional registration and accuracy evaluation method and system. Background Art

[0002] Real-time safety monitoring of open-pit mines is an important guarantee for the safe operation of open-pit mines. Ground-based synthetic aperture radar (GB-SAR) has the technical advantages of all-day, real-time, continuous and high-precision, and has become one of the main monitoring methods for slope instability. However, GB-SAR uses two-dimensional imaging. Even though the deformation monitoring accuracy is very high, it still has the limitation of insufficient dimension in deformation analysis visualization. Especially when the monitored slope or terrain is more complex, the texture of two-dimensional imaging and three-dimensional imaging is quite different, and the accurate position of the deformation area cannot be located. Once the three-dimensional position judgment or registration of the deformation area is wrong, the warning of the dangerous area will fail, thereby causing greater economic losses to the mine.

[0003] Therefore, the three-dimensional accurate registration and accuracy evaluation of GB-SAR are particularly important. At present, the research on mapping GB-SAR two-dimensional images to three-dimensional point clouds still has certain limitations, such as insufficient coordinate correspondence accuracy, large matching errors only relying on the nearest neighbor range, inaccurate matching feature information extraction, and inability to effectively evaluate the registration accuracy. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a GB-SAR image three-dimensional registration and accuracy evaluation method and system.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A GB-SAR image three-dimensional registration and accuracy evaluation method, comprising:

[0007] Acquiring measurement parameters; the measurement parameters include three-dimensional point cloud data of the mine, three-dimensional coordinates of the antenna center point and the guide rail control point of the GB-SAR, and image pixels of the GB-SAR;

[0008] Performing position compensation and optimization on the guide rail control point according to the center point of the antenna to obtain the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine and the nominal length of the guide rail;

[0009] A GB-SAR coordinate system is established with the center of the guide rail as the origin, the horizontal direction as the x-axis, and the direction of the same horizontal plane perpendicular to the guide rail as the y-axis, and the guide rail control points and image pixels are encoded with GB-SAR coordinates based on the nominal length of the guide rail and the GB-SAR system parameters to obtain the coordinates of the guide rail control points and image pixels in the GB-SAR two-dimensional coordinate system;

[0010] Convert the three-dimensional coordinates of the three-dimensional point cloud data into coordinates in a two-dimensional coordinate system of a mine, and establish an implicit mapping relationship of the coordinates;

[0011] Determine the coordinate conversion parameters of the mine two-dimensional coordinate system and the GB-SAR coordinate system based on the coordinates of the guide rail control point in the mine two-dimensional coordinate system and the coordinates of the guide rail control point in the GB-SAR coordinate system;

[0012] The conversion parameters convert the encoded GB-SAR two-dimensional coordinates of the image pixel into the two-dimensional coordinates of the mine, and interpolate and align the three-dimensional coordinates of the image pixel according to the implicit mapping relationship of the coordinates to obtain the interpolated three-dimensional coordinates of the image pixel;

[0013] The accuracy is evaluated based on the three-dimensional coordinates of the image pixels after interpolation.

[0014] Preferably, the obtaining of the measurement parameters comprises:

[0015] Scanning the open-pit mine in the three-dimensional coordinate system of the mine using a three-dimensional laser scanner to obtain the three-dimensional point cloud data;

[0016] A GB-SAR is set on the slope of the open-pit mine, and a reflector is installed at the center position of the antenna of the GB-SAR and the position of the guide rail control point; the guide rail control point includes the left end point and the right end point of the guide rail;

[0017] Using the GB-SAR to collect the image pixels;

[0018] The antenna center point, the left endpoint and the right endpoint are measured respectively by using a total station to obtain the three-dimensional coordinates of the antenna center point, the left endpoint and the right endpoint.

[0019] Preferably, the position compensation and optimization of the guide rail control point according to the antenna center point to obtain the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine and the nominal length of the guide rail include:

[0020] Determine the elevation data of the antenna center point and the guide rail control point according to the three-dimensional coordinates of the antenna center point and the guide rail control point, determine the inclination of the guide rail relative to the horizontal plane based on the elevation difference between the three, and continuously adjust the elevation positions of the two ends of the guide rail until the elevation deviation of the two end points meets the tolerance limit;

[0021] Compensating the elevation data of the guide rail control point according to the elevation data of the antenna center point so that the elevations of the three are equal, and obtaining the three-dimensional coordinates of the compensated guide rail control point;

[0022] Determine the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine according to the three-dimensional coordinates of the compensated guide rail control point;

[0023] The nominal length of the guide rail is determined according to the coordinates of the guide rail control points in the two-dimensional coordinate system of the mine.

[0024] Preferably, a GB-SAR coordinate system is established, and the guide rail control points and image pixels are GB-SAR coordinate encoded based on the nominal length of the guide rail and the GB-SAR system parameters to obtain the coordinates of the guide rail control points and image pixels in the GB-SAR two-dimensional coordinate system, including:

[0025] A GB-SAR two-dimensional coordinate system is established with the center point of the antenna as the origin; the x-axis of the GB-SAR two-dimensional coordinate system is parallel to the straight line connecting the guide rail control points, and the y-axis of the GB-SAR two-dimensional coordinate system is perpendicular to the horizontal plane formed by the guide rail control points and the origin;

[0026] The coordinates of the guide rail control points and the image pixels in the GB-SAR two-dimensional coordinate system are encoded to obtain the coordinates of the guide rail control points and the image pixels in the GB-SAR two-dimensional coordinate system.

[0027] Preferably, the converting the three-dimensional coordinates of the three-dimensional point cloud data into coordinates in a two-dimensional coordinate system of a mine comprises:

[0028] Respectively calculating the spatial distance and horizontal distance between the three-dimensional point cloud data and the central coordinates of the guide rail control point;

[0029] Projection calculation is performed on the three-dimensional point cloud data according to the spatial distance and the horizontal distance to convert the three-dimensional coordinates of the three-dimensional point cloud data into two-dimensional coordinates.

[0030] Preferably, the conversion parameters are determined according to the coordinates of the guide rail control points in the mine two-dimensional coordinate system and the coordinates of the guide rail control points in the GB-SAR coordinate system, including:

[0031] By using the least squares method, coordinate conversion parameters are estimated according to the coordinates of the guide rail control points in the mine two-dimensional coordinate system and the coordinates of the guide rail control points in the GB-SAR coordinate system to obtain the first conversion parameter, the second conversion parameter, the third conversion parameter and the fourth conversion parameter.

[0032] Preferably, the coordinates of the image pixels are converted, interpolated and registered according to the conversion parameters and the implicit coordinate mapping relationship to obtain the interpolated three-dimensional coordinates of the image pixels, that is, the registered three-dimensional coordinates, including:

[0033] The coordinates of the image pixel in the GB-SAR two-dimensional coordinate system are converted according to the conversion parameters to obtain the coordinates of the image pixel in the mine two-dimensional coordinate system;

[0034] Establishing a Delaunay triangulation network based on the two-dimensional coordinates of the mine of the three-dimensional point cloud data;

[0035] According to the spatial relationship of the coordinates in the Delaunay triangulation, the attribute values ​​corresponding to the coordinates of the image pixels in the two-dimensional coordinate system of the mine are calculated by inverse distance weighted calculation to obtain the three-dimensional coordinates of the interpolated image pixels, that is, the three-dimensional coordinates of the image pixels after registration.

[0036] Preferably, the accuracy evaluation is performed according to the three-dimensional coordinates of the interpolated image pixels, including:

[0037] Calculating the Euclidean distance between the three-dimensional coordinates of the image pixel and the central coordinates of the guide rail control point;

[0038] The theoretical distance is calculated based on the GB-SAR image acquisition method;

[0039] Determining distance registration accuracy according to the theoretical distance and the Euclidean distance;

[0040] A plurality of corner reflectors are evenly arranged in the monitoring area of ​​the slope; each of the corner reflectors points to the center point of the antenna;

[0041] Identifying the pixel position of the corner reflector based on the backscatter intensity of the image pixel, and extracting the three-dimensional coordinates of the corner reflector after registration;

[0042] Determining a three-dimensional registration accuracy according to the pixel position and the registered three-dimensional coordinates;

[0043] The registration effect is evaluated according to the distance registration accuracy and the three-dimensional registration accuracy.

[0044] A GB-SAR image three-dimensional registration and accuracy evaluation system, comprising:

[0045] An acquisition module is used to acquire measurement parameters; the measurement parameters include three-dimensional point cloud data of the mine, three-dimensional coordinates of the antenna center point and the guide rail control point of the GB-SAR, and image pixels of the GB-SAR;

[0046] A compensation module, used to perform position compensation on the guide rail control point according to the center point of the antenna, and obtain the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine and the nominal length of the guide rail;

[0047] An encoding module, used for performing GB-SAR coordinate encoding on the guide rail control points and image pixels based on the nominal length of the guide rail and the GB-SAR system parameters, to obtain the coordinates of the guide rail control points and image pixels in the GB-SAR two-dimensional coordinate system;

[0048] A mapping module, used to convert the three-dimensional coordinates of the three-dimensional point cloud data into coordinates in a two-dimensional coordinate system of a mine, and establish an implicit mapping relationship of the coordinates;

[0049] A conversion module, used for determining coordinate conversion parameters based on the coordinates of the guide rail control point in the mine two-dimensional coordinate system and the coordinates of the guide rail control point in the GB-SAR coordinate system;

[0050] An interpolation module, used for converting, interpolating and registering the coordinates of the image pixel according to the coordinate implicit mapping relationship and the conversion parameters to obtain the three-dimensional coordinates of the image pixel after interpolation;

[0051] The evaluation module is used to perform accuracy evaluation based on the three-dimensional coordinates of the interpolated image pixels.

[0052] Preferably, the acquisition module specifically includes:

[0053] A scanning unit, used for scanning the open-pit mine in the three-dimensional coordinate system of the mine using a three-dimensional laser scanner to obtain the three-dimensional point cloud data;

[0054] A setting unit is used to set the GB-SAR on the slope of the open-pit mine, and install a reflector at the center position of the antenna of the GB-SAR and the position of the guide rail control point; the guide rail control point includes the left end point and the right end point of the guide rail;

[0055] An acquisition unit, used for acquiring the image pixels using the GB-SAR;

[0056] The measuring unit is used to measure the center point of the antenna, the left endpoint and the right endpoint respectively by using a total station to obtain the three-dimensional coordinates of the center point of the antenna, the left endpoint and the right endpoint.

[0057] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0058] The present invention provides a GB-SAR image 3D registration and accuracy evaluation method and system, which can automatically register GB-SAR images and 3D terrain coordinates with high accuracy through the acquisition of mine 3D point cloud data, measurement of guide rail control points and coordinate optimization compensation; encoding of guide rail control points and image coordinates based on GB-SAR coordinate system and equipment parameters; projection transformation of 3D point cloud coordinates based on azimuth and distance invariant features; four-parameter conversion calculation of GB-SAR coordinate system and mine coordinate system; 3D coordinate interpolation based on implicit functions of 2D equal azimuth and distance feature coordinates; 3D visualization analysis of slope deformation and registration accuracy evaluation. The method and system can also realize 3D visualization analysis and registration accuracy evaluation of GB-SAR slope monitoring results. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0060] Figure 1 A flowchart of the GB-SAR image three-dimensional registration and accuracy evaluation method in the embodiment provided by the present invention;

[0061] Figure 2 A schematic diagram of the registration evaluation process in the embodiment provided by the present invention;

[0062] Figure 3 A three-dimensional deformation visualization effect diagram in the embodiment provided by the present invention;

[0063] Figure 4 This is a distance error evaluation diagram in the embodiment provided by the present invention. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0066] The terms "first", "second", "third" and "fourth" in the specification and claims of the present application and the drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a series of steps, processes, methods, etc. are not limited to the listed steps, but may optionally include steps that are not listed, or may optionally include other step elements inherent to these processes, methods, products or devices.

[0067] The purpose of the present invention is to provide a GB-SAR image three-dimensional registration and accuracy evaluation method and system, which can automatically perform high-precision registration of GB-SAR images and three-dimensional terrain coordinates, and can realize three-dimensional visualization analysis and registration accuracy evaluation of GB-SAR slope monitoring results.

[0068] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0069] Figure 1 Flow chart of the GB-SAR image 3D registration and accuracy evaluation method in the embodiment provided by the present invention, as shown in FIG. Figure 1 As shown, the present invention provides a GB-SAR image three-dimensional registration and accuracy evaluation method, comprising:

[0070] Step 100: Acquire measurement parameters; the measurement parameters include the three-dimensional point cloud data of the mine, the three-dimensional coordinates of the antenna center point and the guide rail control point of the GB-SAR, and the image pixels of the GB-SAR.

[0071] Step 200: Perform position compensation on the guide rail control point according to the antenna center point to obtain the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine and the nominal length of the guide rail.

[0072] Step 300: Based on the nominal length of the guide rail and the GB-SAR system parameters, the guide rail control points and image pixels are encoded in GB-SAR coordinates to obtain the coordinates of the guide rail control points and image pixels in the GB-SAR two-dimensional coordinate system.

[0073] Step 400: converting the three-dimensional coordinates of the three-dimensional point cloud data into coordinates in a two-dimensional coordinate system of a mine, and establishing an implicit mapping relationship of the coordinates.

[0074] Step 500: Determine conversion parameters based on the coordinates of the guide rail control points in the mine two-dimensional coordinate system and the coordinates of the guide rail control points in the GB-SAR coordinate system.

[0075] Step 600: transform, three-dimensionally interpolate and align the coordinates of the image pixel according to the coordinate implicit mapping relationship and the conversion parameters to obtain the three-dimensional coordinates of the image pixel after interpolation.

[0076] Step 700: Evaluate the registration accuracy based on the interpolated three-dimensional coordinates of the image pixels.

[0077] Figure 2 Schematic diagram of the registration evaluation process in the embodiment provided by the present invention, such as Figure 2 As shown, the registration evaluation process in this embodiment includes:

[0078] S1. Mine 3D point cloud data acquisition, guide rail control point measurement and coordinate compensation.

[0079] S2. Coding of track control points and image coordinates based on GB-SAR coordinate system and equipment parameters.

[0080] S3. Projection transformation of three-dimensional point cloud coordinates based on orientation and distance invariant features.

[0081] Four-parameter transformation calculation of S4, GB-SAR coordinate system and mine coordinate system.

[0082] S5. Three-dimensional coordinate interpolation based on implicit functions of two-dimensional equal-azimuth and equal-distance characteristic coordinates.

[0083] S6. Three-dimensional visualization analysis of slope deformation and evaluation of registration accuracy.

[0084] Among them, the necessary parameters in this embodiment include: the coordinates of the left endpoint of the GB-SAR guide rail, the coordinates of the right endpoint of the GB-SAR guide rail, the coordinate compensation coefficient, and the four parameters of the coordinate system conversion Δx, Δy, α, and k.

[0085] Preferably, the step 100 specifically includes:

[0086] Scanning the open-pit mine in the three-dimensional coordinate system of the mine using a three-dimensional laser scanner to obtain the three-dimensional point cloud data;

[0087] A GB-SAR is set on the slope of the open-pit mine, and a reflector is installed at the center position of the antenna of the GB-SAR and the position of the guide rail control point; the guide rail control point includes the left end point and the right end point of the guide rail;

[0088] Using the GB-SAR to collect the image pixels;

[0089] The antenna center point, the left endpoint and the right endpoint are measured respectively by using a total station to obtain the three-dimensional coordinates of the antenna center point, the left endpoint and the right endpoint.

[0090] Preferably, the step 200 specifically includes:

[0091] Determine the elevation data of the antenna center point and the guide rail control point according to the three-dimensional coordinates of the antenna center point and the guide rail control point, determine the inclination of the guide rail relative to the horizontal plane based on the elevation difference between the three, and continuously adjust the elevation positions of the two ends of the guide rail until the elevation deviation of the two end points meets the tolerance limit;

[0092] Compensating the elevation data of the guide rail control point according to the elevation data of the antenna center point so that the elevations of the three are equal, and obtaining the three-dimensional coordinates of the compensated guide rail control point;

[0093] Determine the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine according to the three-dimensional coordinates of the compensated guide rail control point;

[0094] The nominal length of the guide rail is determined according to the coordinates of the guide rail control points in the two-dimensional coordinate system of the mine.

[0095] Specifically, step S1 is as follows:

[0096] S10. First, use a 3D laser scanner to scan the open-pit mine in the mine's 3D coordinate system to obtain the mine's 3D point cloud data, and then install the slope monitoring equipment GB-SAR. When installing GB-SAR, keep the GB-SAR rail parallel to the xoy plane of the registration coordinate system. Paste Leica high-precision reflectors at the center of the edges of both sides of the GB-SAR rail (the left and right endpoints of GB-SAR) and the center of the antenna, and use a high-precision Leica total station to measure the coordinates of the three. The coordinates of the left endpoint of GB-SAR are (x l ,y l ,h l ), the coordinates of the right endpoint of GB-SAR are (x r ,y r ,h r ), the antenna center coordinates are (x a ,y a ,h a ).

[0097] S11. Let the center elevation of the radar antenna be h a The elevation coordinates of the two end points are h l ,h r , the three must meet the following requirements:

[0098] |h l -h r |<3mm,|h l -h a |<2mm,|h r -h a |<2mm;

[0099] After the above requirements are met, the elevation of the rail control point is compensated according to the antenna elevation, and the coordinates of the rail control point are accurately obtained as (x l ,y l ,h a ) and (x r ,y r ,h a ), and the coordinates of the guide rail control point in the mine two-dimensional coordinate system can be defined as (x l ,y l ) and (x r ,y r ).

[0100] S12. Due to the measurement error and the guide rail length error, the nominal length of the guide rail does not match the actual length. Therefore, the nominal length of the guide rail needs to be corrected. Suppose the nominal length of the guide rail is l t , then l t The calculation formula is:

[0101]

[0102] Optionally, in step S1 of the present embodiment, a three-dimensional laser scanner is first used to obtain three-dimensional point cloud data of the mine, and then a total station is used to obtain the three-dimensional coordinates of the two ends and the center point of the GB-SAR guide rail in the three-dimensional coordinate system of the mine. The coordinates of the control points at both ends of the guide rail are measured and the height difference between the two ends is ensured to be within the limit, and then the coordinate elevation of the center of the guide rail is assigned to the coordinate elevation of the two ends to complete the coordinate compensation, laying the foundation for the four-parameter coordinate conversion.

[0103] Preferably, the step 300 specifically includes:

[0104] A GB-SAR two-dimensional coordinate system is established with the center point of the antenna as the origin; the x-axis of the GB-SAR two-dimensional coordinate system is parallel to the straight line connecting the guide rail control points, and the y-axis of the GB-SAR two-dimensional coordinate system is perpendicular to the plane formed by the guide rail control points and the origin;

[0105] Coordinate encoding is performed on the coordinates of the image pixel in the GB-SAR two-dimensional coordinate system to obtain the coordinates of the image pixel in the GB-SAR two-dimensional coordinate system.

[0106] Specifically, the method for encoding the track control points and image coordinates based on the GB-SAR coordinate system and equipment parameters in step 2 is as follows:

[0107] Guide rail control point coding: based on the corrected guide rail nominal length l t Define the two-dimensional coordinates of the two end points of the guide rail in the GB-SAR coordinate system, where the left end point is (-x gl , 0), the right endpoint is (x gr ,0),x gl and x gr The calculation method is:

[0108]

[0109] Image coordinate encoding: First, the GB-SAR coordinate system is established with the center of the GB-SAR antenna as the origin, the direction of the guide rail as the x-axis, and the direction perpendicular to the guide rail in the horizontal plane xoy as the y-axis. The azimuth resolution of the GB-SAR system is set to a mrad, the range resolution is rm, the starting sampling distance is r0, and the image size is m*n (range direction * azimuth direction). If n is an even number, the image coordinates are encoded according to the following rules:

[0110]

[0111]

[0112]

[0113] If n is an odd number, the image coordinates are encoded according to the following rules:

[0114]

[0115]

[0116]

[0117] Optionally, in step S2 of this embodiment, the image pixels collected by the GB-SAR and the two end points of the GB-SAR track are assigned GB-SAR coordinates according to the equipment parameters, laying the foundation for four-parameter coordinate transformation.

[0118] Preferably, the step 400 specifically includes:

[0119] Respectively calculating the spatial distance and horizontal distance between the three-dimensional point cloud data and the central coordinates of the guide rail control point;

[0120] Projection calculation is performed on the three-dimensional point cloud data according to the spatial distance and the horizontal distance to convert the three-dimensional coordinates of the three-dimensional point cloud data into two-dimensional coordinates.

[0121] Specifically, the projection transformation method of the three-dimensional point cloud coordinates based on the orientation and distance invariant features in step 3 includes the following sub-steps:

[0122] S30, calculate the spatial distance l from the point cloud data to be registered to the center coordinates of the GB-SAR guide rail i,s and horizontal distance l i,h :

[0123]

[0124]

[0125] S31. Based on the following formula, the equidistant projection with the invariant characteristics of orientation and distance is completed, that is, the distance in the three-dimensional space is stretched to the horizontal xoy plane by an equal amount, and the angle between the projection of the spatial straight line to the horizontal plane and the xy axis is kept unchanged, and the three-dimensional coordinates are converted into two-dimensional coordinates:

[0126]

[0127]

[0128] S32, project the three-dimensional coordinates of all point cloud data to the two-dimensional coordinates of the xoy surface based on the orientation and distance invariant features, and establish the following coordinate implicit mapping relationship:

[0129]

[0130] Specifically, in this embodiment, step S3 is to realize the conversion of the three-dimensional point cloud of the mine to be registered into two-dimensional coordinates in the mine coordinate system based on the distance and azimuth invariant features. The coordinate dimension is consistent with the coordinate dimension of the GB-SAR coordinate system in step 2, both of which are two-dimensional, but the information such as the direction of the coordinate axis is inconsistent.

[0131] Preferably, the step 500 specifically includes:

[0132] By using the least square method, the coordinates of the guide rail control point in the mine two-dimensional coordinate system and the coordinates of the guide rail control point in the GB-SAR coordinate system are estimated to obtain the first conversion parameter, the second conversion parameter, the third conversion parameter and the fourth conversion parameter.

[0133] Preferably, the step 600 specifically includes:

[0134] The coordinates of the image pixel in the GB-SAR two-dimensional coordinate system are converted according to the conversion parameters to obtain the coordinates of the image pixel in the mine two-dimensional coordinate system;

[0135] Establishing a Delaunay triangulation network according to the two-dimensional coordinates of the three-dimensional point cloud data;

[0136] According to the spatial relationship of the coordinates in the Delaunay triangulation network, an inverse distance weighted calculation is performed on the attribute values ​​corresponding to the coordinates of the image pixels in the two-dimensional coordinate system of the mine to obtain the three-dimensional coordinates of the interpolated image pixels.

[0137] At present, it is known that the coordinates of the control points at both ends of the GB-SAR track are in the mine coordinate system and the GB-SAR coordinate system respectively. Therefore, step S4 in this embodiment can be performed, that is, the coordinate conversion parameters are calculated according to the four-parameter conversion method of the coordinate system to realize the conversion of the image pixel coordinates in the GB-SAR coordinate system to the mine coordinate system.

[0138] Specifically, the three-dimensional coordinate interpolation process of the implicit function based on the two-dimensional equal orientation and distance characteristic coordinates in step 5 is as follows:

[0139] First, calculate and convert the four parameters according to step 4. The process is as follows:

[0140] According to the left end point coordinates (x l ,y l ), right endpoint coordinates (x r ,y r ) and the left endpoint coordinates in the GB-SAR coordinate system (-x gl ,0), right endpoint coordinates (x gr , 0), the least squares algorithm is used to estimate the four conversion parameters Δx, Δy, α, k, and the conversion of GB-SAR image coordinates to mine coordinates is realized:

[0141] (xc 矿 ,yc 矿 )=f (Δx,Δy,α,k) (x GB-SAR ,y GB-SAR ).

[0142] According to the established implicit functional relationship Establish mapping relationships between x, y, h and xc, yc respectively:

[0143]

[0144]

[0145]

[0146] Based on the known mine point cloud, a Delaunay triangulation network is established to extract the vertex coordinates of the triangular mesh where the matching point is located, and the corresponding three-dimensional coordinates are interpolated based on the inverse distance weighted algorithm. The formula is as follows:

[0147]

[0148] x g =p1f1(x1)+p2f1(x2)+p3f1(x3)

[0149] y g =p1f2(y1)+p2f2(y2)+p3f2(y3).

[0150] h g =p1f3(h1)+p2f3(h2)+p3f3(h3)

[0151] Where p1, p2, p3 are the weights of the triangle mesh vertices, l1, l2, l3 are the distances from the interpolation points to the vertices, and x g ,y g ,h g are the interpolated three-dimensional coordinates, x1, y1, x2, y2, x3, y3 are the vertex coordinates of the triangle mesh.

[0152] In this embodiment, after obtaining the coordinates of the image pixel in the mine coordinate system in step S5, the coordinate system of the image pixel and the two-dimensional coordinates after the three-dimensional coordinates of the point cloud are consistent. Since the three-dimensional coordinates of the mine point cloud and the two-dimensional coordinates have an implicit function mapping relationship, an interpolation function can be established to calculate the three-dimensional coordinates corresponding to the image pixel.

[0153] Preferably, the step 700 includes:

[0154] Calculating the Euclidean distance between the three-dimensional coordinates of the image pixel and the central coordinates of the guide rail control point;

[0155] The theoretical distance is calculated based on the GB-SAR image acquisition method;

[0156] Determining distance registration accuracy according to the theoretical distance and the Euclidean distance;

[0157] A plurality of corner reflectors are evenly arranged in the monitoring area of ​​the slope; each of the corner reflectors points to the center point of the antenna, and the three-dimensional coordinates of the mine of each corner reflector are collected at the same time;

[0158] Identifying the pixel position of the corner reflector based on the backscatter intensity of the image pixel, and extracting the three-dimensional coordinates of the corner reflector after registration;

[0159] Determining the three-dimensional registration accuracy according to the three-dimensional coordinates of the mine of the corner reflector and the registered three-dimensional coordinates;

[0160] The registration effect is evaluated according to the distance registration accuracy and the three-dimensional registration accuracy.

[0161] Specifically, the step S6 also includes the following method:

[0162] The three-dimensional visualization analysis method of slope deformation is as follows: based on the three-dimensional point cloud interpolation result, the result is assigned to the image pixel through image coordinates to complete the registration, and the registered three-dimensional coordinates are drawn into three-dimensional terrain, and the deformation solution result is mapped to the corresponding position of the three-dimensional terrain, and the size of the displacement is represented by color.

[0163] The accuracy after registration can be evaluated from two aspects: distance registration accuracy and three-dimensional registration accuracy. The method is as follows:

[0164] Distance registration accuracy: First, the Euclidean distance L between the three-dimensional coordinates of the pixel and the center coordinates of GB-SAR can be calculated. o , and then the theoretical distance L can be calculated according to the GB-SAR image acquisition method r , the formula is as follows:

[0165]

[0166]

[0167] Where x, y, and z are the three-dimensional coordinates of the pixel, x G ,y G , z G is the center coordinate of GB-SAR, y p The distance to the pixel coordinate.

[0168] The distance registration accuracy is evaluated according to the following formula:

[0169]

[0170] Where ΔL is the distance registration error, and m and n are the image sizes.

[0171] Three-dimensional registration accuracy: Six corner reflectors are evenly arranged in the slope monitoring area and aligned with the center of the GB-SAR antenna. The 3D coordinates of the center of the corner reflector are accurately measured using RTK. The pixel position of the corner reflector in the image is identified based on the backscattering intensity of the GB-SAR image, and the 3D coordinates of the corner reflector after registration are extracted. The 3D registration accuracy can be calculated using the following formula:

[0172]

[0173] Where a is the number of corner reflectors, Δx, Δy, and Δh are the registration accuracy in three dimensions.

[0174] Optionally, in step S6 of this embodiment, the theoretical sampling distance of the image is first calculated according to the GB-SAR parameters, and then the distance after registration is calculated by the three-dimensional coordinates of the GB-SAR antenna center and the image pixel, and the difference between the two can be used to evaluate the registration accuracy.

[0175] It should be noted that: the step 1 of collecting three-dimensional point cloud data of mines, measuring guide rail control points and coordinate compensation method includes the following sub-steps:

[0176] First, a 3D laser scanner is used to scan the open-pit mine in the 3D coordinate system of the mine to obtain the 3D point cloud data of the mine. Then, the slope monitoring equipment GB-SAR is installed. When installing GB-SAR, the GB-SAR rail is kept parallel to the xoy plane of the registration coordinate system. Leica high-precision reflectors are pasted at the center of the edges of both sides of the GB-SAR rail (the left and right endpoints of GB-SAR) and the center of the antenna. The coordinates of the three are measured using a high-precision Leica total station. The coordinates of the left endpoint of GB-SAR are (x l ,y l ,h l ), the coordinates of the right endpoint of GB-SAR are (x r ,y r ,h r ), the antenna center coordinates are (x a ,y a ,h a ).

[0177] Assume the center elevation of the radar antenna is h a The elevation coordinates of the two end points are h l ,h r , the three must meet the following requirements:

[0178] |h l -h r |<3mm,|h l -h a |<2mm,|h r -h a |<2mm;(1)

[0179] After meeting the above requirements, the elevation of the guide rail control point is compensated according to the antenna elevation. The compensation method is that when the elevation of the two end points meets the tolerance requirements, the two end points and the center point can be considered to be at the same elevation. The elevation of the center point is used to replace the elevation of the two end points, and the three-dimensional coordinates of the guide rail control point in the mine three-dimensional coordinate system are accurately obtained as (x l ,y l ,h a ) and (x r ,y r ,h a ), and the coordinates of the guide rail control point in the mine two-dimensional coordinate system can be defined as (x l ,y l ) and (x r ,y r(This step is to obtain the three-dimensional coordinates of the control points at both ends of the rail, and then calculate the length of the rail, which is used for the subsequent two-dimensional coordinate calculation and four-parameter coordinate transformation of the control points at both ends of the rail in the GB-SAR two-dimensional coordinate system).

[0180] The guide rail control point and image coordinate encoding method of step 2 in this embodiment is as follows:

[0181] Guide rail control point coding: based on the corrected guide rail nominal length l t Define the two-dimensional coordinates of the two end points of the guide rail in the GB-SAR coordinate system, where the left end point is (-x gl , 0), the right endpoint is (x gr ,0),x gl and x gr The calculation method is:

[0182]

[0183] Image coordinate encoding: First, take the center of the GB-SAR antenna as the origin, the direction of the guide rail as the x-axis, and the direction perpendicular to the guide rail in the horizontal plane xoy as the y-axis to establish the GB-SAR coordinate system, encode the coordinates of the GB-SAR image pixels in the GB-SAR two-dimensional coordinate system, and obtain the coordinates of the GB-SAR image pixels in the GB-SAR two-dimensional coordinate system. At the same time, use the three-dimensional coordinates of the control points obtained in step 1 to calculate the length of the guide rail, and encode the coordinates of the two end points of the GB-SAR guide rail in the GB-SAR two-dimensional coordinate system to obtain the coordinates of the two end points of the GB-SAR guide rail in the GB-SAR two-dimensional coordinate system. After that, the coordinates of the two end points of the GB-SAR guide rail in the mine two-dimensional coordinate system and the GB-SAR coordinate system are known respectively, and four-parameter calculation can be performed to obtain the conversion parameters of the mine two-dimensional coordinate system and the GB-SAR coordinate system. Then, the coordinates of the GB-SAR image pixels in the GB-SAR coordinate system are converted to the coordinates in the mine two-dimensional coordinate system. At this time, the coordinates of the GB-SAR image pixels in the mine two-dimensional coordinate system are known, which lays the foundation for the subsequent three-dimensional coordinate interpolation calculation.

[0184] Assume that the azimuth resolution of the GB-SAR system is a mrad, the range resolution is rm, the starting sampling distance is r0, and the image size is m*n (range direction*azimuth direction). If n is an even number, the image coordinates are encoded according to the following rules:

[0185]

[0186]

[0187]

[0188] Where θ is the GB-SAR scanning deflection angle, x i,j and i,j It is the coordinates of GB-SAR image pixels encoded in the GB-SAR coordinate system.

[0189] If n is an odd number, the image coordinates are encoded according to the following rules:

[0190]

[0191]

[0192]

[0193] In step 3 of this embodiment, the three-dimensional point cloud coordinate system is projected and transformed based on the invariant characteristics of orientation and distance, that is, the formula for converting the three-dimensional coordinates of the mine point cloud into two-dimensional coordinates is:

[0194]

[0195]

[0196]

[0197]

[0198] Where l i,s is the Euclidean distance from the 3D point cloud to the center of the GB-SAR antenna, l i,h is the Euclidean distance from the 3D point cloud to the center of the GB-SAR antenna after being projected onto the 2D plane, x i ,y i ,h i is the three-dimensional coordinate, xc i and yc i It is the two-dimensional coordinate after the projection transformation of the three-dimensional point cloud coordinate system based on the invariant characteristics of orientation and distance.

[0199] In step 4 of this embodiment, in the four-parameter conversion calculation between the GB-SAR coordinate system and the mine coordinate system, the left end point coordinates (x l ,y l ), right endpoint coordinates (x r ,y r ) and the left endpoint coordinates in the GB-SAR coordinate system (-x gl ,0), right endpoint coordinates (x gr , 0), and use the least squares algorithm to estimate the four conversion parameters Δx, Δy, α, and k. The specific formula is as follows:

[0200]

[0201] in:

[0202]

[0203] According to the least squares theory:

[0204] X=(B T PB) -1 B T PL (15)

[0205] Where P is the unit matrix, x n and x o The control point coordinates of the transformed coordinate system and the original coordinate system respectively.

[0206] Substituting the control points at both ends of the guide rail into the above formula, the four parameters Δx, Δy, α, and k can be calculated. The estimated four parameters can be used to realize the conversion of GB-SAR image coordinates to mine coordinates:

[0207] (xc 矿 ,yc 矿 )=f (Δx,Δy,α,k) (x i,j ,y i,j ) (16) Specifically:

[0208]

[0209] In step 5 of this embodiment, the three-dimensional coordinate interpolation based on the implicit function of the two-dimensional equal orientation and distance feature coordinates is specifically based on the two-dimensional coordinates (xc i , yc i ) to establish a Delaunay triangulation network. At this time, the pixel coordinates of the converted GB-SAR image (xc 矿 , yc 矿 ) will fall inside each triangle in the triangulation network, and the two coordinates belong to the same coordinate system. The two-dimensional coordinates (xc i , yc i ) and three-dimensional coordinates (x i ,y i ,h i ), so the values ​​of each dimension of the three-dimensional coordinates can be used as the three implicit function attribute data of the two-dimensional coordinates. At this time, the attribute values ​​corresponding to the two-dimensional coordinates of the GB-SAR image pixels can be calculated by inverse distance weighting according to the spatial relationship of the coordinates in the triangulation network, and finally the corresponding three-dimensional coordinate data can be obtained. The calculation method for interpolating the corresponding three-dimensional coordinates based on the inverse distance weighted algorithm is:

[0210]

[0211]

[0212] Where p1, p2, p3 are the weights of the triangle mesh vertices, l1, l2, l3 are the distances from the interpolation points to the vertices, and x g ,y g ,h g are the interpolated three-dimensional coordinates, x1, y1, x2, y2, x3, y3 are the vertex coordinates of the triangle mesh.

[0213] In step 6 of this embodiment, the three-dimensional visualization analysis of slope deformation is the registration accuracy evaluation, and the distance registration error calculation formula is:

[0214]

[0215] Where ΔL is the distance registration error, and m and n are the image sizes.

[0216] The calculation formula of the three-dimensional registration error in this embodiment is:

[0217]

[0218] Where a is the number of corner reflectors, Δx, Δy, and Δh are the registration accuracy in three dimensions.

[0219] This embodiment also includes the following steps:

[0220] A) Guide rail control point measurement:

[0221] When installing GB-SAR during the monitoring process, keep the GB-SAR rail and the xoy plane of the registration coordinate system parallel, paste Leica high-precision reflectors on the center positions of the two side edges of the GB-SAR rail (the left and right end points of GB-SAR) and the center position of the antenna, and use a high-precision Leica total station to measure the coordinates of the three.

[0222] B) Guide rail length compensation:

[0223] Due to measurement errors and guide rail length errors, the nominal length of the guide rail does not match the actual length, so the nominal length of the guide rail needs to be corrected.

[0224] C) Image Coordinate Encoding

[0225] GB-SAR images record echo data in a two-dimensional matrix of distance and azimuth. The scanning area corresponds to a sector-shaped area and has no elevation information. Therefore, in order to complete three-dimensional registration, it is necessary to encode the coordinates of the control points at both ends of the guide rail and the image pixels according to information such as the GB-SAR system parameters.

[0226] D) 2D projection transformation of 3D point cloud coordinates

[0227] The slope only retains the azimuth and distance information during the imaging process of GB-SAR images, so the three-dimensional point cloud coordinates need to be converted into two-dimensional coordinates during coordinate registration.

[0228] E) Four-parameter coordinate transformation calculation

[0229] After converting the three-dimensional coordinates into two-dimensional coordinates based on equal distance and orientation, the image coordinates and the two-dimensional coordinates are at the same scale, but the origin and direction of the coordinate system are different. Therefore, the coordinate system conversion parameters are calculated based on the least squares algorithm and the control point coordinates, and the conversion from image coordinates to two-dimensional coordinates is completed based on the calculated four parameters.

[0230] F) Image 3D coordinate interpolation

[0231] According to the correspondence between the three-dimensional coordinates and their two-dimensional projection coordinates, an implicit function mapping between the two can be established. The image coordinates after coordinate conversion and the two-dimensional projection coordinates belong to the same coordinate system. Therefore, the three-dimensional coordinates corresponding to the image pixel coordinates can be interpolated according to the implicit function relationship. The specific method is to establish a Delaunay triangulation network with the two-dimensional projection coordinates, and perform three-dimensional coordinate interpolation on the converted image pixel coordinates in the network based on inverse distance weighting to achieve three-dimensional image registration.

[0232] G) Registration accuracy evaluation

[0233] First, the Euclidean distance L between the three-dimensional coordinates of the pixel and the center coordinates of GB-SAR can be calculated. o , and then the theoretical distance L can be calculated according to the GB-SAR image acquisition method r .

[0234] Six corner reflectors are evenly arranged in the slope monitoring area and aligned with the center of the GB-SAR antenna. The 3D coordinates of the mine at the center of the corner reflector are accurately measured using RTK. The pixel position of the corner reflector in the image is identified based on the backscattering intensity of the GB-SAR image, and the 3D coordinates of the corner reflector after registration are extracted to obtain the 3D registration accuracy.

[0235] The following is an example of GB-SAR slope monitoring of the Nanfen open-pit iron ore mine in Benxi City, which is a rock slope. First, GB-SAR image data and the three-dimensional point cloud of the mine slope are collected, and the three-dimensional registration is realized based on the equidistant projection GB-SAR image three-dimensional registration method, and the distance registration accuracy is evaluated to verify the effect of the present invention.

[0236] 1) GB-SAR monitoring data acquisition and rail coordinate measurement compensation

[0237] First, GB-SAR was installed in a stable area of ​​the Nanfen open-pit iron ore mine in Benxi City, keeping the GB-SAR rail parallel to the xoy plane of the registration coordinate system. Leica high-precision reflectors were pasted at the center of the edges of both sides of the GB-SAR rail (the left and right endpoints of GB-SAR) and the center of the antenna, and the coordinates of the three were measured and compensated using a high-precision Leica total station. At the same time, GB-SAR and laser scanners were used to collect image data and point cloud data, and GB-SAR was processed to obtain slope deformation.

[0238] 2) Guide rail control point and image coordinate encoding

[0239] The GB-SAR coordinate system is established with the center of the GB-SAR antenna as the origin, the direction of the guide rail as the x-axis, and the direction perpendicular to the guide rail in the horizontal plane xoy as the y-axis. The coordinates of the guide rail control points and image pixels are encoded according to the encoding rules of step C based on the GB-SAR system parameters to obtain the encoded coordinates.

[0240] 3) 2D projection transformation of 3D point cloud coordinates

[0241] Based on the equal-angle rule, the Euclidean distance from the three-dimensional point cloud coordinates to the center of the GB-SAR antenna is projected onto the horizontal xoy plane, and the projected two-dimensional coordinates are calculated based on the equidistance projection.

[0242] 4) Four-parameter coordinate transformation calculation

[0243] Firstly, the coordinates of both ends of the guide rail in the two-dimensional coordinate system of the mine and the GB-SAR coordinate system are determined respectively. Then, the two end points are used as known control points for coordinate transformation. The four parameters of plane coordinate transformation are calculated based on the least squares algorithm. Then, the four parameters are used to transform the encoded GB-SAR coordinates to obtain the two-dimensional coordinates of the image pixels in the mine coordinate system.

[0244] 5) Image 3D coordinate interpolation

[0245] According to the correspondence between the three-dimensional coordinates and their two-dimensional projection coordinates, an implicit function mapping is established between the two, and the two-dimensional projection coordinates are used to establish a Delaunay triangulation network. The formula in step F is used to interpolate the three-dimensional coordinates of the converted image pixel coordinates in the network based on inverse distance weighting to achieve three-dimensional image registration.

[0246] 6) Deformation 3D visualization and registration accuracy evaluation

[0247] The deformation corresponding to the pixel is matched with the three-dimensional coordinates, and then a three-dimensional point cloud is drawn. The displacement size is represented by color to achieve three-dimensional visualization and analysis of the deformation. The effect is as follows Figure 3As shown in FIG. 1 , the registration accuracy is evaluated by using two indicators, namely, the distance registration accuracy based on system parameters and the three-dimensional registration accuracy based on corner reflectors. The distance registration accuracy after registration using the present invention can reach the centimeter level. Figure 4 shown.

[0248] This embodiment also provides a GB-SAR image three-dimensional registration and accuracy evaluation system, including:

[0249] An acquisition module is used to acquire measurement parameters; the measurement parameters include three-dimensional point cloud data of the mine, three-dimensional coordinates of the antenna center point and the guide rail control point of the GB-SAR, and image pixels of the GB-SAR;

[0250] A compensation module, used to perform position compensation on the guide rail control point according to the center point of the antenna, and obtain the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine and the nominal length of the guide rail;

[0251] An encoding module, used for encoding the guide rail control points and image pixels in the GB-SAR coordinate system to obtain the coordinates of the guide rail control points and image pixels in the GB-SAR two-dimensional coordinate system;

[0252] A mapping module, used to convert the three-dimensional coordinates of the three-dimensional point cloud data into coordinates in a two-dimensional coordinate system of a mine, and establish an implicit mapping relationship of the coordinates;

[0253] A conversion module, used to determine conversion parameters according to the coordinates of the guide rail control point in the mine two-dimensional coordinate system and the coordinates of the guide rail control point in the GB-SAR coordinate system;

[0254] An interpolation module, used for converting, interpolating and registering the coordinates of the image pixel according to the coordinate implicit mapping relationship and the conversion parameters to obtain the three-dimensional coordinates of the image pixel after interpolation;

[0255] The evaluation module is used to perform accuracy evaluation based on the three-dimensional coordinates of the interpolated image pixels.

[0256] Preferably, the acquisition module specifically includes:

[0257] A scanning unit, used for scanning the open-pit mine in the three-dimensional coordinate system of the mine using a three-dimensional laser scanner to obtain the three-dimensional point cloud data;

[0258] A setting unit is used to set the GB-SAR on the slope of the open-pit mine, and install a reflector at the center position of the antenna of the GB-SAR and the position of the guide rail control point; the guide rail control point includes the left end point and the right end point of the guide rail;

[0259] An acquisition unit, used for acquiring the image pixels using the GB-SAR;

[0260] The measuring unit is used to measure the center point of the antenna, the left endpoint and the right endpoint respectively by using a total station to obtain the three-dimensional coordinates of the center point of the antenna, the left endpoint and the right endpoint.

[0261] The beneficial effects of the present invention are as follows:

[0262] (1) The present invention can effectively improve the registration accuracy of GB-SAR and three-dimensional point clouds and accurately map deformation information into three-dimensional space.

[0263] (2) The present invention can perform three-dimensional visualization analysis of deformation information through registration to achieve accurate positioning and delineation of dangerous areas, thus providing guarantee for safe operation of mines.

[0264] (3) Based on the registration error assessment method, the present invention can quantitatively and accurately evaluate the registration accuracy of GB-SAR images and three-dimensional point clouds.

[0265] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0266] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A GB-SAR image three-dimensional registration and accuracy evaluation method, characterized in that: include: Acquiring measurement parameters; the measurement parameters include three-dimensional point cloud data of the mine, three-dimensional coordinates of the antenna center point and the guide rail control point of the GB-SAR, and image pixels of the GB-SAR; Performing position compensation on the guide rail control point according to the center point of the antenna to obtain the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine and the nominal length of the guide rail; Based on the nominal length of the guide rail and the GB-SAR system parameters, the guide rail control points and the image pixels are encoded with GB-SAR coordinates to obtain the coordinates of the guide rail control points and the image pixels in the GB-SAR two-dimensional coordinate system; Convert the three-dimensional coordinates of the three-dimensional point cloud data into coordinates in a two-dimensional coordinate system of a mine, and establish an implicit mapping relationship of the coordinates; Determining conversion parameters based on the coordinates of the guide rail control point in the mine two-dimensional coordinate system and the coordinates of the guide rail control point in the GB-SAR coordinate system; The coordinates of the image pixel are converted, interpolated and registered according to the coordinate implicit mapping relationship and the conversion parameters to obtain the three-dimensional coordinates of the image pixel after interpolation; The accuracy is evaluated based on the three-dimensional coordinates of the image pixels after interpolation.

2. The GB-SAR image three-dimensional registration and accuracy evaluation method according to claim 1, characterized in that: The obtaining of the measurement parameters comprises: Scanning the open-pit mine in the three-dimensional coordinate system of the mine using a three-dimensional laser scanner to obtain the three-dimensional point cloud data; A GB-SAR is set on the slope of the open-pit mine, and a reflector is installed at the center position of the antenna of the GB-SAR and the position of the guide rail control point; the guide rail control point includes the left end point and the right end point of the guide rail; Using the GB-SAR to collect the image pixels; The antenna center point, the left endpoint and the right endpoint are measured respectively by using a total station to obtain the three-dimensional coordinates of the antenna center point, the left endpoint and the right endpoint.

3. The GB-SAR image three-dimensional registration and accuracy evaluation method according to claim 1, characterized in that: The position compensation of the guide rail control point according to the center point of the antenna to obtain the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine and the nominal length of the guide rail includes: Determine the elevation data of the antenna center point and the guide rail control point according to the three-dimensional coordinates of the antenna center point and the guide rail control point; Compensating the elevation data of the guide rail control point according to the elevation data of the antenna center point to obtain the three-dimensional coordinates of the compensated guide rail control point; Determine the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine according to the three-dimensional coordinates of the compensated guide rail control point; The nominal length of the guide rail is determined according to the coordinates of the guide rail control points in the two-dimensional coordinate system of the mine.

4. The GB-SAR image three-dimensional registration and accuracy evaluation method according to claim 1, characterized in that: The encoding of the image pixel based on the coordinates of the guide rail control point in the mine two-dimensional coordinate system to obtain the coordinates of the image pixel in the GB-SAR two-dimensional coordinate system includes: A GB-SAR two-dimensional coordinate system is established with the center point of the antenna as the origin; the x-axis of the GB-SAR two-dimensional coordinate system is parallel to the straight line connecting the guide rail control points, and the y-axis of the GB-SAR two-dimensional coordinate system is perpendicular to the plane formed by the guide rail control points and the origin; GB-SAR coordinate encoding is performed on the guide rail control points and image pixels to obtain the coordinates of the guide rail control points and image pixels in the GB-SAR two-dimensional coordinate system.

5. The GB-SAR image three-dimensional registration and accuracy evaluation method according to claim 1, characterized in that: The step of converting the three-dimensional coordinates of the three-dimensional point cloud data into coordinates in a two-dimensional coordinate system of a mine includes: Respectively calculating the spatial distance and horizontal distance between the three-dimensional point cloud data and the central coordinates of the guide rail control point; Projection calculation is performed on the three-dimensional point cloud data according to the spatial distance and the horizontal distance to convert the three-dimensional coordinates of the three-dimensional point cloud data into two-dimensional coordinates.

6. The GB-SAR image three-dimensional registration and accuracy evaluation method according to claim 1, characterized in that: Determining conversion parameters based on the coordinates of the guide rail control point in the mine two-dimensional coordinate system and the coordinates of the guide rail control point in the GB-SAR coordinate system includes: By using the least square method, the coordinates of the guide rail control point in the mine two-dimensional coordinate system and the coordinates of the guide rail control point in the GB-SAR coordinate system are estimated to obtain the first conversion parameter, the second conversion parameter, the third conversion parameter and the fourth conversion parameter.

7. The GB-SAR image three-dimensional registration and accuracy evaluation method according to claim 1, characterized in that: The step of converting, interpolating and registering the coordinates of the image pixel according to the coordinate implicit mapping relationship and the conversion parameters to obtain the three-dimensional coordinates of the image pixel after interpolation includes: The coordinates of the image pixel in the GB-SAR two-dimensional coordinate system are converted according to the coordinate implicit mapping relationship and the conversion parameters to obtain the coordinates of the image pixel in the mine two-dimensional coordinate system; Establishing a Delaunay triangulation network according to the two-dimensional coordinates of the three-dimensional point cloud data; According to the spatial relationship of the coordinates in the Delaunay triangulation network, an inverse distance weighted calculation is performed on the attribute values ​​corresponding to the coordinates of the image pixels in the two-dimensional coordinate system of the mine to obtain the three-dimensional coordinates of the interpolated image pixels.

8. The GB-SAR image three-dimensional registration and accuracy evaluation method according to claim 1, characterized in that: The step of performing accuracy evaluation based on the interpolated three-dimensional coordinates of the image pixel comprises: Calculating the Euclidean distance between the three-dimensional coordinates of the image pixel and the central coordinates of the guide rail control point; The theoretical distance is calculated based on the GB-SAR image acquisition method; Determining distance registration accuracy according to the theoretical distance and the Euclidean distance; A plurality of corner reflectors are evenly arranged in the monitoring area of ​​the slope; each of the corner reflectors points to the center point of the antenna and collects its three-dimensional coordinates of the mine; Identifying the pixel position of the corner reflector based on the backscatter intensity of the image pixel, and extracting the three-dimensional coordinates of the corner reflector after registration; Determining a three-dimensional registration accuracy according to the pixel position and the registered three-dimensional coordinates; The registration effect is evaluated according to the distance registration accuracy and the three-dimensional registration accuracy.

9. A GB-SAR image three-dimensional registration and accuracy evaluation system, characterized in that: include: An acquisition module is used to acquire measurement parameters; the measurement parameters include three-dimensional point cloud data of the mine, three-dimensional coordinates of the antenna center point and the guide rail control point of the GB-SAR, and image pixels of the GB-SAR; A compensation module, used to perform position compensation on the guide rail control point according to the center point of the antenna, and obtain the coordinates of the guide rail control point in the two-dimensional coordinate system of the mine and the nominal length of the guide rail; An encoding module, used for performing GB-SAR coordinate encoding on the guide rail control points and image pixels based on the nominal length of the guide rail and the GB-SAR system parameters, to obtain the coordinates of the guide rail control points and image pixels in the GB-SAR two-dimensional coordinate system; A mapping module, used to convert the three-dimensional coordinates of the three-dimensional point cloud data into coordinates in a two-dimensional coordinate system of a mine, and establish an implicit mapping relationship of the coordinates; A conversion module, used to determine conversion parameters based on the coordinates of the guide rail control point in the mine two-dimensional coordinate system and the coordinates of the guide rail control point in the GB-SAR coordinate system; An interpolation module, used for converting, interpolating and registering the coordinates of the image pixel according to the coordinate implicit mapping relationship and the conversion parameters to obtain the three-dimensional coordinates of the image pixel after interpolation; The evaluation module is used to perform accuracy evaluation based on the three-dimensional coordinates of the interpolated image pixels.

10. The GB-SAR image three-dimensional registration and accuracy evaluation system according to claim 9, characterized in that: The acquisition module specifically includes: A scanning unit, used for scanning the open-pit mine in the three-dimensional coordinate system of the mine using a three-dimensional laser scanner to obtain the three-dimensional point cloud data; A setting unit is used to set the GB-SAR on the slope of the open-pit mine, and install a reflector at the center position of the antenna of the GB-SAR and the position of the guide rail control point; the guide rail control point includes the left end point and the right end point of the guide rail; An acquisition unit, used for acquiring the image pixels using the GB-SAR; The measuring unit is used to measure the center point of the antenna, the left endpoint and the right endpoint respectively by using a total station to obtain the three-dimensional coordinates of the center point of the antenna, the left endpoint and the right endpoint.

Images