Arc orbit slope radar deformation map and unmanned aerial vehicle topographic survey registration method

Abstract

The application discloses a kind of circular arc track slope radar deformation map and unmanned aerial vehicle topographic survey terrain registration method, it is related to slope radar technical field, its technical solution key point is: registration slope radar, input center point A and antenna point B coordinates;Read deformation map, store as two-dimensional matrix;Cyclic slope point cloud file, obtain each three-dimensional point P;Generation vector AB and vector AP, utilize vector cross product, by the positive and negative of calculation result, determine whether P point is in the left side or right side of vector AB;S5.Calculate cos ∠BAP using vector method;Using arccos function calculates out ∠BAP radian value and converts into angle;Select angle value, go to two-dimensional deformation map and match best angle;Calculate the three-dimensional distance of point A and point P, go to two-dimensional deformation map and match best distance;From two-dimensional matrix search matched azimuth and slant range, the application is based on the method for calculating the azimuth of three-dimensional point relative to the axis of slope radar, can adapt to the case of axis in any orientation in slope radar.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of slope radar, more particularly, it relates to a method for registering a circular arc track slope radar deformation map and an unmanned aerial vehicle topographic survey terrain. BACKGROUND

[0002] Slope-SAR is a short form of Ground-Based Synthetic Aperture Radar (GB-SAR) system applied in the field of slope deformation monitoring. Slope-SAR realizes two-dimensional imaging through track movement of the antenna: high range resolution is obtained through wideband electromagnetic wave signals in the range direction, and high azimuth resolution is obtained through synthetic aperture technology in the azimuth direction. The system obtains time-series radar deformation maps through repeated observation of a specific scene, and sub-millimeter level deformation data can be extracted using phase information, forming a high-precision deformation monitoring system that is all-weather and all-day. In typical application scenarios, the observation area usually has an independent three-dimensional coordinate system, and high-precision terrain data can be obtained through unmanned aerial vehicle topographic survey and three-dimensional laser scanning. In order to realize the spatial registration of the radar deformation map coordinate system and the three-dimensional coordinate system of the observation scene, and accurately map the three-dimensional spatial position of the deformation area, it is necessary to establish a geometric mapping relationship between the radar deformation map and the terrain data.

[0003] The current mainstream method is to construct a spatial conversion model of the radar deformation map coordinate system and the geographic coordinate system, realize the deep fusion of scattering characteristics and terrain features, generate a comprehensive image with three-dimensional geographic coordinates and radar scattering features, and intuitively display the terrain structure of the deformation area, providing an accurate spatial reference for deformation quantitative analysis. The specific approach is to match based on slant range and azimuth angle. In the radar deformation map, the azimuth angle of each pixel relative to the axis of the image is read, the azimuth angle of each three-dimensional point relative to the axis of the radar is calculated in three-dimensional space, and matching is made based on a certain tolerance. Yang Jun published a paper entitled "Geometric Mapping Three-Dimensional Matching Method of Ground-Based SAR Image and Terrain Data" in Journal of University of Chinese Academy of Sciences, which uses the inverse sine algorithm to calculate the azimuth angle of the three-dimensional point relative to the slope radar. However, in fact, the orientation of the slope radar in three-dimensional space is not always due south or due north. As shown in Figure 1 , using the inverse sine algorithm will result in errors. In view of this, the present application provides a method for registering a two-dimensional deformation map of a slope radar and a three-dimensional real scene terrain. SUMMARY

[0004] The purpose of the present application is to provide a method for registering a circular arc track slope radar deformation map and an unmanned aerial vehicle topographic survey terrain, which solves the above problems.

[0005] The above technical purpose of the present application is realized by the following technical scheme:

[0006] The first aspect of the present application provides a circular arc track slope radar deformation map and unmanned aerial vehicle photogrammetry terrain registration method, comprising the following steps:

[0007] S1. Start registering the slope radar, input the center point A and the antenna point B coordinates;

[0008] S2. Read the two-dimensional deformation map and store it as a two-dimensional matrix;

[0009] S3. Input the three-dimensional slope point cloud file, and loop to parse the three-dimensional slope point cloud file to obtain each three-dimensional point P;

[0010] S4. Generate vectors AB and AP, ignore the elevation, use vector cross product, and determine whether the P point is on the left side or the right side of the vector AB by calculating the positive or negative of the result;

[0011] S5. Calculate cos ∠BAP using vector method;

[0012] S6. Calculate the radian value of ∠BAP and convert it to an angle;

[0013] S7. Based on the judgment in step S4, select the angle value within 180 or the angle value outside 180, and use the bisection method to match the best angle in the two-dimensional deformation map;

[0014] S8. Calculate the three-dimensional distance between points A and P, and use the bisection method to match the best distance in the two-dimensional deformation map;

[0015] S9. Search for the matching azimuth and slant range from the two-dimensional matrix, and loop to calculate the azimuth and slant range of each three-dimensional point P.

[0016] In combination with the first aspect, the present application is further provided that: in step S1, the radar is a straight track slope radar, a circular arc track slope radar, and an array slope radar.

[0017] In combination with the first aspect, the present application is further provided that: in step S1, the radar is a circular arc track slope radar.

[0018] In combination with the first aspect, the present application is further provided that: in step S2, the two-dimensional matrix contains pixel azimuth and slant range information.

[0019] In combination with the first aspect, the present application is further provided that: in step S4, the cross product of vectors AB and AP is

[0020]

[0021] When ∠BAP < 180°, the calculation result is positive, and when ∠BAP > 180°, the calculation result is negative.

[0022] In combination with the first aspect, the application further provides that in step S5, the cos ∠BAP is calculated by the following specific steps:

[0023]

[0024] S5.1, first, calculate the modulus of vectors and .

[0025] S5.2, calculate the dot product of vectors and .

[0026] S5.3, then, divide the result of the dot product by the product of the modulus of the two vectors to obtain the cos included angle:

[0027] The second aspect of the application also provides a device / equipment / system for registering a circular arc track slope radar deformation map and an unmanned aerial vehicle aerial survey terrain, comprising a memory, a processor and a computer program stored in the memory, and the processor executes the computer program to implement the steps of any of the above methods.

[0028] The third aspect of the application also provides a computer readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the steps of any of the above methods.

[0029] The fourth aspect of the application also provides a computer program product comprising a computer program / instruction, which, when executed by a processor, implements the steps of any of the above methods.

[0030] In summary, the application has the following beneficial effects:

[0031] The method for calculating the azimuth angle of a three-dimensional point relative to the central axis of a slope radar based on the vector method can adapt to the case where the central axis of the slope radar is in any orientation. The positive and negative signs of the vector can quickly determine the quadrant in which the three-dimensional point is located in the slope radar coordinate system. At the same time, this method can adapt to linear track slope radars, circular arc track slope radars and array slope radars. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is the actual state of the azimuth angle calculation;

[0033] Figure 2 is a flow chart of the method for registering a circular arc track slope radar deformation map and an unmanned aerial vehicle aerial survey terrain in the embodiment of the application;

[0034] Figure 3is a 360 radar registration map in the embodiment of the present application;

[0035] Figure 4 is a radar deformation map of a circular arc track slope and a registration effect of a UAV aerial survey terrain in the embodiment of the present application Figure 1 ;

[0036] Figure 5 is a radar deformation map of a circular arc track slope and a registration effect of a UAV aerial survey terrain in the embodiment of the present application Figure 2 ;

[0037] Figure 6 is a radar deformation map of a circular arc track slope and a registration effect of a UAV aerial survey terrain in the embodiment of the present application Figure 3 ;

[0038] Figure 7 is a radar deformation map of a circular arc track slope and a registration effect of a UAV aerial survey terrain in the embodiment of the present application Figure 4 ;

[0039] Figure 8 is a 360 radar registration effect check in the embodiment of the present application. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] Embodiment 1:

[0042] A circular arc track slope radar deformation map and a UAV aerial survey terrain registration method, as shown in Figure 2 , includes the following steps:

[0043] S1. Start registering the slope radar, input the center point A and the antenna point B coordinates, in the embodiment, a circular arc track slope radar (360 radar) is adopted, Figure 3 is registered for the 360 radar, but the method is applicable to linear track slope radars and array slope radars;

[0044] S2. Read the two-dimensional deformation map and store it as a two-dimensional matrix, which contains pixel azimuth angle and slant range information;

[0045] S3. Input the three-dimensional slope point cloud file, and loop to parse the three-dimensional slope point cloud file to obtain each three-dimensional point P;

[0046] S4. Generate vector AB and vector AP, ignore the height for simplification, use vector cross product to determine whether P is on the left or right side of vector AB,

[0047]

[0048] That is, when ∠BAP < 180° (the result is positive); when ∠BAP > 180° (the result is negative).

[0049] S5. Calculate the cos value of ∠BAP by using vector method;

[0050] Calculation and The cos of the angle in two-dimensional space can use the following steps:

[0051] S5.1 First, calculate the modulus of vector and :

[0052] S5.2 Calculate the dot product of vector and :

[0053] S5.3 Then use the dot product result divided by the product of the modulus of the two vectors to get the cos of the angle:

[0054] S6. Calculate the radian value of ∠BAP by using arccos function and convert it to angle;

[0055] S7. Based on the judgment in step S4, select the angle value within 180 or the angle value outside 180 to match the best angle in the two-dimensional deformation map by using bisection method;

[0056] S8. Calculate the three-dimensional distance of point A and point P, and match the best distance in the two-dimensional deformation map by using bisection method;

[0057] S9. Search the matching azimuth and slant range from the two-dimensional matrix and return to loop to calculate the azimuth and slant range of each three-dimensional point P.

[0058] The second aspect of the application also provides a device / equipment / system for registering a slope radar two-dimensional deformation map and a real scene three-dimensional terrain, comprising a memory, a processor and a computer program stored in the memory, and the processor executes the computer program to realize the steps of any method described above.

[0059] The third aspect of the present application also provides a computer readable storage medium, which stores computer programs / instructions, and the computer programs / instructions are executed by a processor to realize the steps of any of the above-mentioned methods.

[0060] The fourth aspect of the present application also provides a computer program product, which comprises computer programs / instructions, and the computer programs / instructions are executed by a processor to realize the steps of any of the above-mentioned methods.

[0061] The registration effect is shown as Figure 4 , Figure 5 , Figure 6 and Figure 7 . Figure 8 The registration effect is checked for 360 radars.

[0062] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the foregoing detailed description of the present application is made with reference to the foregoing embodiments, for those skilled in the art, it still can be modified to the technical solutions recorded in the foregoing embodiments, or equivalent replacement of some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for registering radar deformation maps of circular arc track slopes with UAV aerial survey terrain, characterized by: Includes the following steps: S1. Start registering the slope radar, input the coordinates of the center point A and the antenna point B; S2. Read the two-dimensional deformation diagram and store it as a two-dimensional matrix; S3. Input a 3D slope point cloud file and parse the 3D slope point cloud file in a loop to obtain each 3D point P; S4. Generate vectors AB and AP, ignoring elevation, and use the cross product of vectors to determine whether point P is to the left or right of vector AB by calculating the sign of the result; S5. Calculate cos∠BAP using the vector method; S6. Calculate the radian value of ∠BAP and convert it to degrees; S7. Based on the judgment in step S4, select an angle value within 180 degrees or an angle value outside 180 degrees, and use the bisection method to match the best angle in the two-dimensional deformation diagram. S8. Calculate the three-dimensional distance between point A and point P, and use the bisection method to find the optimal distance in the two-dimensional deformed graph; S9. Search for matching azimuth and slope distance from the two-dimensional matrix, and return the azimuth and slope distance of each three-dimensional point P in a loop.

2. The method for registering radar deformation maps of circular arc track slopes with UAV aerial survey terrain according to claim 1, characterized in that: In step S1, the slope radar is a circular track slope radar, a straight track slope radar, or an array-type slope radar.

3. The method for registering radar deformation maps of circular arc track slopes with UAV aerial survey terrain according to claim 1, characterized in that: In step S2, the two-dimensional matrix contains pixel azimuth angle and slant distance information.

4. The method for registering radar deformation maps of circular arc track slopes with UAV aerial survey terrain according to claim 1, characterized in that: in In step S4, the cross product of vectors AB and AP is: When ∠BAP < 180°, the calculation result is positive; when ∠BAP > 180°, the calculation result is negative.

5. The method for registering radar deformation maps of circular arc track slopes with UAV aerial survey terrain according to claim 1, characterized in that: in In step S5, the specific steps for calculating cos∠BAP are as follows: S5.1 First calculate the vector and Modulus length: S5.2 Calculate Vectors and dot product: S5.3 Then, using the result of the dot product, divide it by the product of the magnitudes of the two vectors to obtain the cosine angle:

6. A device / equipment / system for registering radar deformation maps of circular arc track slopes with UAV aerial survey terrain, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1-5.

7. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that... When the computer program / instruction is executed by the processor, it implements the steps of the method described in any one of claims 1-5.

8. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method described in any one of claims 1-5.

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