Slope radar data accurate visualization method, readable storage medium and equipment

Abstract

The invention relates to the technical field of geological disaster monitoring and early warning, in particular to a slope radar data accurate visualization method, a readable storage medium and equipment. The method comprises the following steps: acquiring a data set by radar; performing data preprocessing; converting the coordinate values of the three-dimensional terrain points into a two-dimensional polar coordinate space to obtain polar coordinates corresponding to the three-dimensional terrain points; and the slope radar distinguishing unit is matched with the three-dimensional topographic points, and three-dimensional space coordinates corresponding to the slope radar distinguishing unit are calculated. According to the method, three-dimensional space is mapped to polar coordinates, three-dimensional topographic points near a slope radar resolution unit are preliminarily screened in combination with a buffer area, then the nearest three-dimensional topographic points in the upper, lower, left and right directions are secondarily screened out, and finally accurate three-dimensional space coordinates of the slope radar resolution unit are estimated through an inverse distance weighted interpolation method. One-to-one correspondence and accurate mapping of two-dimensional polar coordinates and three-dimensional space coordinates of radar monitoring data are realized, and a basis is provided for subsequent data visualization and monitoring early warning analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of geological disaster monitoring and early warning, and in particular to a method for accurately visualizing slope radar data, a readable storage medium and a device. Background Art

[0002] With the development of remote sensing technology, slope radar and lidar technology have been widely used in the field of geological disaster monitoring and early warning. In actual use, the data obtained by slope radar is usually two-dimensional polar coordinate data, which needs to be displayed in three-dimensional geographic space in order to better visualize slope radar data and conduct disaster analysis.

[0003] At present, the data of ground-based synthetic aperture radar (slope radar) is two-dimensional polar coordinate data, which consists of two dimensions (r, θ), where r is the distance in three-dimensional space and θ is the plane rotation angle. Due to the lack of vertical rotation angle φ, the data of ground-based radar cannot be converted into three-dimensional space, and the process of converting the two-dimensional data (r, θ) of ground-based radar into three-dimensional space (x, y, z) is a nonlinear calculation. Therefore, it is impossible to simply achieve a one-to-one correspondence between slope radar data and three-dimensional terrain points.

[0004] The existing technology generally directly uses two-dimensional polar coordinates to display the monitoring data of the slope radar, or sets a target (corner reflector) at the monitoring site, determines the three-dimensional geographic space coordinates of the target, and then searches for the corresponding radar data according to the target's transmission signal, and corresponds it to the three-dimensional space coordinates for visualization. In addition, some algorithms realize the three-dimensional visualization of radar monitoring data by normalizing the point cloud data of the three-dimensional laser radar to the two-dimensional polar coordinate space of the slope radar, and then establishes the corresponding relationship between the point cloud and the slope radar resolution unit. Although this method realizes the three-dimensional display of radar monitoring data by establishing the corresponding relationship between the three-dimensional point cloud and the two-dimensional slope radar resolution unit, the calculation efficiency of the method of searching the point cloud one by one for calculation is relatively low due to the large amount of three-dimensional point cloud data. Moreover, since the terrain data obtained by the three-dimensional laser radar is discrete, the result of its calculation is a rough correspondence, and it is not an accurate calculation of the three-dimensional rectangular coordinate value of the slope radar resolution unit in the three-dimensional geographic space. In the subsequent calculation of the boundary and area of ​​the large deformation area, it is difficult to obtain accurate results, which not only affects the speed of visualization, but also affects the early warning analysis. However, the method of directly displaying two-dimensional polar coordinate data or displaying limited target monitoring data fails to take advantage of the massive data of slope radar monitoring, and the display effect is not intuitive enough.

[0005] In summary, there is an urgent need for a method that can quickly and accurately convert radar two-dimensional polar coordinate data into three-dimensional geographic spatial coordinate data to solve the problems existing in the prior art. Summary of the invention

[0006] The present invention aims to provide a slope radar data accurate visualization method, a readable storage medium and a device that can realize the rapid and accurate conversion of radar two-dimensional polar coordinate data into three-dimensional geographic spatial coordinate data. The specific technical scheme is as follows:

[0007] A method for accurately visualizing slope radar data comprises the following steps:

[0008] Step 1: Use radar to obtain data sets;

[0009] Step 2: preprocess the data set obtained in step 1 to obtain the coordinate values ​​of the three-dimensional terrain points;

[0010] Step 3: Based on the coordinate values ​​of the three-dimensional terrain point obtained in step 2, the coordinate values ​​are converted into the two-dimensional polar coordinate space to obtain the polar coordinates (r c ,θ c );

[0011] Step 4: Match the slope radar resolution unit with the three-dimensional terrain point and calculate the three-dimensional spatial coordinates corresponding to the slope radar resolution unit, specifically including:

[0012] Step S4.1: Assume the coordinates of the slope radar resolution unit to be (r target ,θ target ), the polar coordinates corresponding to the three-dimensional terrain points obtained from step 3 (r c ,θ c ) to preliminarily select the point pts1 near the slope radar resolution unit, which satisfies the following formula:

[0013] r δ ≤|r c -r target | and θ δ ≤|θ c -θ target |;

[0014] Where: r δ ,θ δ is the size of the buffer, r δ ≥2×RngRes,θ δ ≥2×AngRes, RngRes is the range resolution of the slope radar, AngRes is the angle resolution of the slope radar;

[0015] Step S4.2, find out the nearest neighboring points pt1, pt2, pt3 and pt4 of the slope radar resolution unit from the initially screened pts1;

[0016] Step S4.3, using the inverse distance weighted interpolation method based on the four points pt1, pt2, pt3 and pt4 selected in step S4.2, calculate the slope radar resolution unit (rtarget ,θ target ) corresponds to the three-dimensional space coordinate (x target ,y target , z target ).

[0017] Preferably, the step S4.2 comprises:

[0018] Filter from pts1 that satisfy θ c -θ target >0 point set pts up , then from pts up Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt1, its corresponding two-dimensional polar coordinates are (r1, θ1) and its three-dimensional spatial coordinates are (x1, y1, z1);

[0019] Filter from pts1 to satisfy θ c -θ target Point set pts ≤ 0 down , then from pts down Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt2, its corresponding two-dimensional polar coordinates are (r2, θ2), and its three-dimensional spatial coordinates are (x2, y2, z2);

[0020] Filter from pts1 to meet r c -r target >0 point set pts right , then from pts right Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt3, its corresponding two-dimensional polar coordinates are (r3, θ3) and its three-dimensional spatial coordinates are (x3, y3, z3);

[0021] Filter from pts1 to meet r c -r target Point set pts ≤ 0 left , then from pts left Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt4 has corresponding two-dimensional polar coordinates (r4, θ4) and three-dimensional space coordinates (x4, y4, z4).

[0022] Preferably, the three-dimensional space coordinates (xtarget ,y target , z target ) are as follows:

[0023]

[0024] Where: 1≤i≤4; ω is the weight, weight function γ i =|θ i -θ target |, α and β are the weight factors of distance and angle, respectively, α ≥ 1, 0.01 ≤ β ≤ 0.5.

[0025] Preferably, in step 2: the three-dimensional coordinates of the point P1 where the slope radar itself is located are (x r ,y r , z r ); The three-dimensional coordinates of the angle starting point P2 of the slope radar (x s ,y s , z s ), the angle θ of the slope radar is The angle of clockwise rotation, the value range of θ is [0, 2π].

[0026] Preferably, in step three:

[0027] Assume the coordinates of the three-dimensional terrain point P3 are (x c ,y c , z c );

[0028] Then the polar coordinates (r c ,θ c ) is calculated using the following formula:

[0029]

[0030] Among them: vector vector P1P2·P1P3 is a vector and The dot product of P1P2·P1P3=(x s -x r )(x c -x r )+(y s -y r )(y c -y r ); |P1P2| and |P1P3| are vectors and The model, P1P2×P1P3 is a vector and The outer product of P1P2×P1P3=(x s -x r )(y c -y r )-(y s -y r )(x c -x r ).

[0031] The application of the technical solution of the present invention has the beneficial effect that the method for accurate visualization of slope radar data disclosed in the present invention includes the following steps: using laser radar to obtain a data set; performing data preprocessing to obtain coordinate values ​​of three-dimensional terrain points; converting the obtained three-dimensional terrain point coordinate values ​​into two-dimensional polar coordinate space to obtain polar coordinates corresponding to the three-dimensional terrain points; matching the slope radar resolution unit with the three-dimensional terrain points to calculate the three-dimensional space coordinates corresponding to the slope radar resolution unit. The solution of the present invention maps the three-dimensional space to polar coordinates, combines the buffer zone to preliminarily screen the three-dimensional terrain points near the slope radar resolution unit, and then screens the nearest three-dimensional terrain points in the four directions of up, down, left and right for a second time, and finally estimates the accurate three-dimensional space coordinates of the slope radar resolution unit through the inverse distance weighted interpolation method, realizing the one-to-one correspondence and accurate mapping between the two-dimensional polar coordinates and the three-dimensional space coordinates of the radar monitoring data, providing a basis for subsequent data visualization and monitoring and early warning analysis.

[0032] The present invention also discloses a readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned method for accurately visualizing slope radar data is implemented.

[0033] The present invention also discloses a device, comprising: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the above-mentioned method for accurate visualization of slope radar data by executing the executable instructions.

[0034] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail with reference to the embodiments below. DETAILED DESCRIPTION

[0035] The following is a detailed description of embodiments of the present invention, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0036] Example:

[0037] A method for accurately visualizing slope radar data, comprising the following steps:

[0038] Step 1: Use slope radar to obtain data sets;

[0039] Preferably in this embodiment, the three-dimensional geographic coordinates (x, y, z, r, g, b) collected by equipment such as laser radar, (x, y, z) are the three-dimensional spatial coordinates of the terrain point, and (r, g, b) are the color values ​​corresponding to the terrain point.

[0040] Step 2: preprocess the data set obtained in step 1 to obtain the coordinate values ​​of the three-dimensional terrain points.

[0041] In this embodiment: read the slope radar data parameters, assuming that the three-dimensional coordinates of the point P1 where the slope radar itself is located is (x r ,y r , z r ), the range resolution of the slope radar is RngRes, the angle resolution of the slope radar is AngRes, and the three-dimensional coordinates of the angle starting point P2 of the slope radar (x s ,y s ,z s ), the angle θ of the slope radar is The angle of clockwise rotation, the value range of θ is [0, 2π].

[0042] Step 3: Based on the coordinate values ​​of the three-dimensional terrain point obtained in step 2, the coordinate values ​​are converted into the two-dimensional polar coordinate space to obtain the polar coordinates (r c ,θ c ), specifically:

[0043] Assume the coordinates of the three-dimensional terrain point P3 are (x c ,y c , z c );

[0044] Then the polar coordinates (r c ,θ c ) is calculated using the following formula:

[0045]

[0046] Among them: vector vector P1P2·P1P3 is a vector and The dot product of P1P2·P1P3=(x s -x r )(x c -x r )+(y s -y r )(y c -y r ); |P1P2| and |P1P3| are vectors and The model, P1P2×P1P3 is a vector and The outer product of P1P2×P1P3=(x s -x r )(y c -y r )-(y s -y r )(x c -x r ).

[0047] Step 4: Match the slope radar resolution unit with the three-dimensional terrain point and calculate the three-dimensional spatial coordinates corresponding to the slope radar resolution unit, specifically including:

[0048] Step S4.1: Assume the coordinates of the slope radar resolution unit to be (r target ,θ target ), the polar coordinates corresponding to the three-dimensional terrain points obtained from step 3 (r c ,θ c ) to preliminarily select the point pts1 near the slope radar resolution unit, which satisfies the following formula:

[0049] r δ ≤|r c -r target | and θ δ ≤|θ c -θ target |;

[0050] Where: r δ ,θ δ is the size of the buffer, r δ ≥2×RngRes,θ δ ≥2×AngRes;

[0051] Step S4.2, find the nearest neighboring points pt1, pt2, pt3 and pt4 of the target resolution unit from the initially screened pts1. The detailed operation is:

[0052] Filter from pts1 that satisfy θ c -θ target >0 point set pts up , then from pts up Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt1, its corresponding two-dimensional polar coordinates are (r1, θ1) and its three-dimensional spatial coordinates are (x1, y1, z1);

[0053] Filter from pts1 to satisfy θc -θ target Point set pts ≤ 0 down , then from pts down Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt2, its corresponding two-dimensional polar coordinates are (r2, θ2), and its three-dimensional spatial coordinates are (x2, y2, z2);

[0054] Filter from pts1 to meet r c -r target >0 point set pts right , then from pts right Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt3, its corresponding two-dimensional polar coordinates are (r3, θ3) and its three-dimensional spatial coordinates are (x3, y3, z3);

[0055] Filter from pts1 to meet r c -r target Point set pts ≤ 0 left , then from pts left Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt4 has corresponding two-dimensional polar coordinates (r4, θ4) and three-dimensional space coordinates (x4, y4, z4).

[0056] Step S4.3, using the inverse distance weighted interpolation method based on the four points pt1, pt2, pt3 and pt4 selected in step S4.2, calculate the slope radar resolution unit (r target ,θ target ) corresponds to the three-dimensional space coordinate (x target ,y target , z target ), as follows:

[0057]

[0058] Where: 1≤i≤4; ω is the weight, weight function d i =|r i -r target |, γ i =|θ i -θ target|, α and β are weight factors of distance and angle, respectively, which are used to control the strength of weighting. In this embodiment: α determines the influence of distance in weight calculation, α≥1, and the weight of closer points is greater; β is used to adjust the influence of angle difference in interpolation calculation, 0.01≤β≤0.5.

[0059] The technical solution of this embodiment is specifically:

[0060] The key to the solution of this embodiment is to effectively and accurately align the two-dimensional polar coordinate data of the radar with the three-dimensional terrain data, and use a suitable interpolation method to estimate the precise three-dimensional spatial coordinates of the slope radar resolution unit. The method proposed in this embodiment is simple and easy to implement with high accuracy. It maps the three-dimensional space to polar coordinates, combines the buffer zone to preliminarily screen the three-dimensional terrain points near the slope radar resolution unit, and then secondary screens the nearest three-dimensional terrain points in the four directions of up, down, left and right. Finally, the precise three-dimensional spatial coordinates of the slope radar resolution unit are estimated by the inverse distance weighted interpolation method, realizing the one-to-one correspondence and precise mapping between the two-dimensional polar coordinates and the three-dimensional spatial coordinates of the radar monitoring data, providing a basis for subsequent data visualization and monitoring and early warning analysis.

[0061] This embodiment also discloses a readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned method for accurately visualizing slope radar data is implemented.

[0062] This embodiment also discloses a device, including: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the above-mentioned method for accurate visualization of slope radar data by executing the executable instructions.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for accurate visualization of slope radar data, characterized in that: The steps include: Step 1: Use radar to obtain data sets; Step 2: preprocess the data set obtained in step 1 to obtain the coordinate values ​​of the three-dimensional terrain points; Step 3: Based on the coordinate values ​​of the three-dimensional terrain point obtained in step 2, the coordinate values ​​are converted into the two-dimensional polar coordinate space to obtain the polar coordinates (r c ,θ c ); Step 4: Match the slope radar resolution unit with the three-dimensional terrain point and calculate the three-dimensional spatial coordinates corresponding to the slope radar resolution unit, specifically including: Step S4.1: Assume the coordinates of the slope radar resolution unit to be (r target ,θ target ), the polar coordinates corresponding to the three-dimensional terrain points obtained from step 3 (r c ,θ c ) to preliminarily select the point pts1 near the slope radar resolution unit, which satisfies the following formula: r δ ≤|r c -r target |and the δ ≤|θ c -θ target |; Where: r δ ,θ δ is the size of the buffer, r δ ≥2×RngRes,θ δ ≥2×AngRes, RngRes is the range resolution of the slope radar, AngRes is the angle resolution of the slope radar; Step S4.2, find the nearest neighboring points pt1, pt2, pt3 and pt4 of the target resolution unit from the initially screened pts1; Step S4.3, using the inverse distance weighted interpolation method based on the four points pt1, pt2, pt3 and pt4 selected in step S4.2, calculate the slope radar resolution unit (r target ,θ target ) corresponds to the three-dimensional space coordinate (x target ,y target ,z target ).

2. The method for accurate visualization of slope radar data according to claim 1, characterized in that: The step S4.2 comprises: Filter from pts1 that satisfy θ c -θ target >0 point set pts up , then from pts up Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt1, its corresponding two-dimensional polar coordinates are (r1, θ1) and three-dimensional space coordinates are (x1, y1, z1); Filter from pts1 to meet θ c -θ target Point set pts ≤ 0 down , then from pts down Calculate the distance (r) point by point target ,θ target The nearest point, The smallest point pt2, its corresponding two-dimensional polar coordinates are (r2, θ2), and its three-dimensional spatial coordinates are (x2, y2, z2); Filter from pts1 to meet r c -r target >0 point set pts right , then from pts right Calculate the distance (r) point by point target ,θ target The nearest point, The smallest point pt3, its corresponding two-dimensional polar coordinates are (r3, θ3) and three-dimensional spatial coordinates are (x3, y3, z3); Filter from pts1 to meet r c -r target Point set pts ≤ 0 left , then from pts left Calculate the distance (r) point by point target ,θ target ) nearest point, i.e. The smallest point pt4 has corresponding two-dimensional polar coordinates (r4, θ4) and three-dimensional space coordinates (x4, y4, z4).

3. The method for accurate visualization of slope radar data according to claim 2, characterized in that: The three-dimensional space coordinates (x target ,y target ,z target ) are as follows: Where: 1≤i≤4; ω is the weight, weight function d i =|r i -r target |, γ i =|θ i -θ target |, α and β are the weight factors of distance and angle, respectively, α ≥ 1, 0.01 ≤ β ≤ 0.

5.

4. A method for accurately visualizing slope radar data according to any one of claims 1 to 3, characterized in that: In step 2: the three-dimensional coordinates of the point P1 where the slope radar itself is located are (x r ,y r ,z r ); The three-dimensional coordinates of the angle starting point P2 of the slope radar (x s ,y s ,z s ), the angle θ of the slope radar is The angle of clockwise rotation, the value range of θ is [0,2π].

5. The method for accurate visualization of slope radar data according to claim 4, characterized in that: In the step three: Assume the coordinates of the three-dimensional terrain point P3 are (x c ,y c ,z c ); Then the polar coordinates (r c ,θ c ) is calculated using the following formula: Among them: vector vector P1P2·P1P3 is a vector and The dot product of P1P2·P1P3=(x s -x r )(x c -x r )+(y s -y r )(y c -y r ); |P1P2| and |P1P3 are vectors and The model, P1P2×P1P3 is a vector and The outer product of P1P2×P1P3=(x s -x r )(y c -y r )-(y s -y r )(x c -x r ).

6. A readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for accurately visualizing slope radar data according to any one of claims 1 to 5 is implemented.

7. A device, characterized in that: include: processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the method for accurate visualization of slope radar data according to any one of claims 1 to 6 by executing the executable instructions.

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