Geometric correction method and device for placement error of unmanned aerial vehicle radar

Abstract

The present invention provides a method for geometrically correcting the placement error of an unmanned aerial vehicle (UAV) radar, comprising: arranging a plurality of reflective markers in a calibration field, and arranging reference points and checkpoints outside the calibration field; obtaining the coordinates of each reflective marker based on the reference points and the checkpoints; controlling an unmanned aerial vehicle (UAV) equipped with a laser radar to fly back and forth along a preset route through the plurality of reflective markers, and obtaining the attitude information and position information of the UAV; obtaining the slant distance and beam splitting angle from an emission point of the laser radar to a ground reflection point; constructing an error equation according to the coordinates of the reflective marker, the slant distance, the beam splitting angle, the attitude information and the position information based on the position offset and rotational geometric relationship between the laser radar and an integrated navigation system; solving the error equation to obtain the systematic error of the placement angle of the UAV-mounted radar; and geometrically correcting the placement angle using the systematic error of the placement angle.

Description

Technical Field

[0001] The present invention relates to the field of laser radar technology, and in particular to a method and device for geometrically correcting placement errors of unmanned aerial vehicle-borne radar. Background Art

[0002] Unmanned Aerial Vehicle Light Detection and Ranging (UAVLR) is an active remote sensing technology that can quickly obtain three-dimensional spatial information of terrain surfaces. It integrates high-precision laser scanners, position and attitude measurement systems, power supply and distribution modules, and integrated control and storage modules. Different from traditional optical imaging mechanisms, the acquisition of target ground data by UAV LIDAR can be independent of lighting conditions.

[0003] The unmanned aerial vehicle laser radar is composed of multiple payloads such as the position and attitude measurement system and the laser scanner. In theory, strict alignment between multiple sensors should be ensured during system integration. However, due to technical limitations, there are certain placement errors between the component systems. The system placement angle error is mainly caused by the non-parallelism between the laser scanning coordinate system and the inertial platform coordinate system, including pitch angle error, roll angle error and yaw angle error. The existence of placement error will not only affect the absolute accuracy of the point cloud coordinates, but also cause three-dimensional spatial offset between the same-name features in overlapping flight strips, affecting the subsequent processing and application of point cloud data. Therefore, it is particularly important to remove the system placement angle error through the rigorous geometric imaging model of the unmanned aerial vehicle laser radar, so as to accurately extract the subsequent point cloud information.

[0004] In the process of realizing the concept of the present invention, the inventors found that the calibration accuracy of the UAV-mounted LiDAR system using methods such as manual calibration, flight track adjustment or establishing a system error model in the prior art is not high and needs to be improved. Summary of the invention

[0005] In view of this, the present invention provides a method for geometric correction of radar placement errors on unmanned aerial vehicles, comprising: arranging multiple reflective markers in a calibration field, and arranging reference points and check points outside the calibration field; obtaining the coordinates of each reflective marker based on the reference points and the check points; controlling an unmanned aerial vehicle equipped with a laser radar to fly back and forth along a preset route through the multiple reflective markers to obtain attitude information and position information of the unmanned aerial vehicle; obtaining the slant distance and beam splitting angle from the laser radar emission point to the ground reflection point; constructing an error equation based on the position offset and rotational geometric relationship between the laser radar and the integrated navigation system according to the coordinates of the reflective marker, the slant distance, the beam splitting angle, the attitude information and the position information; solving the error equation to obtain the systematic error of the placement angle of the unmanned aerial vehicle radar; and using the systematic error of the placement angle to geometrically correct the placement angle.

[0006] According to an embodiment of the present invention, the acquiring the coordinates of each reflective marker based on the reference point and the checkpoint includes: taking the reference point as a survey station and the checkpoint as an orientation point, and using a total station to acquire the coordinates of each reflective marker respectively.

[0007] According to an embodiment of the present invention, the step of obtaining the attitude information and position information of the drone includes: setting up a GPS base station at the reference point; using the reference point as the base station and adopting GPS post-differentiation to perform combined navigation solution to obtain the attitude information and the position information.

[0008] According to an embodiment of the present invention, the step of constructing a geometric verification model based on the position offset and rotational geometric relationship between the laser radar and the integrated navigation system and according to the slant range, the beam splitting angle, the attitude information and the position information includes: constructing the error equation based on the principle of minimizing the distance residual of the slant range.

[0009] According to an embodiment of the present invention, the error equation is:

[0010]

[0011] in:

[0012]

[0013]

[0014]

[0015] in, is the distance residual of the slant range ρ, ρ x , y , z are the components of the slant distance in the x, y, and z directions in the WGS-84 spatial rectangular coordinate system, ρ x0 , y0 , z0 They are ρ x , y , z The initial value of is the coordinate of the i-th reflection mark in the WGS-84 space rectangular coordinate system, is the coordinate of the antenna phase center corresponding to the i-th reflector in the WGS-84 space rectangular coordinate system, [ΔX Ai_IMU ΔY Ai_IMU ΔZ Ai_IMU ] T is the linear offset between the laser emission reference center corresponding to the i-th reflective mark and the inertial unit reference center, R wgs84is the transformation matrix from the Northwest High coordinate system to the WGS-84 space rectangular coordinate system; R ENU is the transformation matrix from the north-eastern coordinate system to the north-west coordinate system; R H is the instantaneous azimuth attitude rotation matrix of the inertial measurement unit; R P is the instantaneous pitch attitude rotation matrix of the inertial measurement unit; R R is the instantaneous roll attitude angle rotation matrix of the inertial measurement unit, R M is the placement angle rotation matrix between the laser emission reference center and the inertial unit reference center, ω, κ is the azimuth attitude angle, pitch attitude angle and roll attitude angle respectively, α is the angle between the projection of the laser emission light path on the XOY plane of the body coordinate system and the positive direction of the X axis, β is the angle between the laser emission light path and its projection line on the XOY plane, dω, dκ are ω, κ is the correction value of κ, and dρ is the correction value of the distance residual corresponding to ρ.

[0016] According to an embodiment of the present invention, the solving of the error equation to obtain the system error of the UAV-borne radar installation angle includes: solving the error equation that is less than a preset threshold. The corresponding dω, dκ, dρ are regarded as the systematic errors of the installation angle.

[0017] According to an embodiment of the present invention, the error equation is solved by an iterative solution method.

[0018] According to an embodiment of the present invention, the geometric correction of the installation angle by using the system error of the installation angle comprises: dκ and dρ are respectively added to the ω and κ and ρ are the installation angles after geometric correction.

[0019] On the other hand, the present invention provides a geometric correction device for the placement error of an unmanned aerial vehicle (UAV) radar, comprising: a deployment module, used to deploy multiple reflective markers in a calibration field, and to deploy reference points and check points outside the calibration field; a first acquisition module, used to acquire the coordinates of each reflective marker based on the reference points and the check points; a second acquisition module, used to control an unmanned aerial vehicle (UAV) equipped with a laser radar to fly back and forth along a preset route through the multiple reflective markers, and acquire the attitude information and position information of the UAV; a third acquisition module, used to acquire the slant distance and beam splitting angle from the laser radar emission point to the ground reflection point; a construction module, used to construct an error equation based on the position offset and rotational geometric relationship between the laser radar and the integrated navigation system, according to the coordinates of the reflective marker, the slant distance, the beam splitting angle, the attitude information and the position information; a calculation module, used to solve the error equation and obtain the systematic error of the placement angle of the UAV-mounted radar; and a correction module, used to perform geometric correction on the placement angle using the systematic error of the placement angle.

[0020] According to the geometric correction method for the placement error of the unmanned aerial vehicle radar provided by the present invention, a plurality of ground control points are arranged, ground reflection marks are used as geometric control points, and an error equation corresponding to the placement angle error of the unmanned aerial vehicle radar is constructed based on the principle of minimum residual of the distance from the laser radar emission point to the ground geometric control point. The system error parameters of the placement angle are solved by the least squares iterative calculation method, and the optimal solution for the placement error of the airborne laser radar can be achieved, thereby improving the three-dimensional accuracy of the laser radar point cloud, and ultimately improving the accuracy of the application of point cloud data in other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0022] Figure 1 The flowchart of the method for geometric correction of placement error of a UAV-mounted radar according to an embodiment of the present invention is schematically shown.

[0023] Figure 2 The design layout of the reflective mark according to the embodiment of the present invention is schematically shown.

[0024] Figure 3 The design layout of reference points and check points according to an embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are 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.

[0026] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0027] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the description of the present invention, it should be understood that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the subsystem or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present invention. The shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual size, proportion, and actual positional relationship. In addition, in the present invention, any reference symbol between brackets should not be constructed as a limitation to the present invention.

[0030] Similarly, in order to simplify the present invention and help understand one or more of the various disclosed aspects, in the above description of exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. The description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0032] Aiming at the existing problems in the calibration of the installation angle of UAV-mounted LiDAR, a method of eliminating the installation error of UAV-mounted LiDAR by arranging multiple reflective markers on the ground is proposed, based on an in-depth study of the data acquisition mechanism of airborne LiDAR and the influence of the installation angle error between multiple sensors on the LiDAR point cloud data. The ground target is used as the geometric control point, and the installation angle error of the scanner on the UAV-mounted platform and the integrated navigation system is corrected by least squares iterative calculation. Finally, the installation angle error is brought into the solution model of the UAV-mounted LiDAR to realize the geometric calibration of the installation error parameters of the UAV-mounted LiDAR.

[0033] Figure 1 The flowchart of the method for geometric correction of placement error of a UAV-mounted radar according to an embodiment of the present invention is schematically shown.

[0034] like Figure 1 As shown, the remote sensing image target extraction method may include, for example, operations S101 to S106.

[0035] In operation S101 , a plurality of reflective markers are arranged in a calibration field, and reference points and check points are arranged outside the calibration field.

[0036] In an embodiment of the present invention, an area is demarcated on a flat ground to form a calibration field, a plurality of control points are arranged at equal intervals on the calibration field, a reflective marker is arranged on each control point, and a reference point and a check point are arranged outside the control points.

[0037] Figure 2The design layout of the reflective mark according to the embodiment of the present invention is schematically shown.

[0038] Figure 3 The design layout of reference points and check points according to an embodiment of the present invention is schematically shown.

[0039] like Figure 2 As shown in the figure, for example, 16 control points A1, A2, ... A16 are arranged at equal intervals on a flat ground, a 1cm*1cm strong reflective mark is arranged on each control point, and a reference point B1 and a check point B2 are arranged outside the 16 control points. It should be understood that the number of control points can be selected according to actual needs, and the present invention does not limit it.

[0040] In operation S102 , the coordinates of each reflective marker are acquired based on the reference point and the check point.

[0041] In the embodiment of the present invention, firstly, the coordinates of the reference point B1 and the check point B2 in the WGS84 space rectangular coordinates are obtained by using the method of joint measurement with the known control points. and

[0042] Then, using the reference point B1 as the measuring station and the check point B2 as the orientation point, the coordinates of the reflection marks of the control points are obtained by using a total station. For example, the coordinates of the reflection marks of 16 control points A1, A2, ..., A16 are obtained.

[0043] In operation S103, the drone equipped with the laser radar is controlled to fly back and forth along a preset route passing through a plurality of reflective markers to obtain attitude information and position information of the drone.

[0044] In the embodiment of the present invention, firstly, a GPS base station may be set up on the reference point B1 for static observation.

[0045] Then, the laser radar device is mounted on the drone, and the drone is controlled to fly back and forth along a fixed route passing through all control points. Point B1 is used as the base station, and GPS post-differential technology is used for combined navigation solution to obtain the drone's attitude and position information.

[0046] In operation S104, the slant distance and beam splitting angle from the laser radar emission point to the ground reflection point are obtained.

[0047] In the embodiment of the present invention, the slant distance refers to the slant distance from the laser radar system emission point to the ground reflection point (laser foot point), and the beam splitting angle includes the angles α and β between the laser and the XOY plane of the scanner.

[0048] In operation S105, based on the position offset and rotational geometric relationship between the laser radar and the integrated navigation system, an error equation is constructed according to the coordinates, slant range, beam splitting angle, attitude information and position information of the reflection mark.

[0049] First, establish the point cloud coordinates of the reflector in the forward and return routes, as follows:

[0050]

[0051] in, is the coordinate of the target in the WGS-84 rectangular coordinate system; is the coordinate of the antenna phase center in the WGS-84 rectangular coordinate system, R wgs84 is the transformation matrix from the Northwest High coordinate system to the WGS-84 space rectangular coordinate system; R ENU is the transformation matrix from the north-eastern coordinate system to the north-west coordinate system; R H is the instantaneous azimuth attitude rotation matrix of the inertial measurement unit; R P is the instantaneous pitch attitude rotation matrix of the inertial measurement unit; RR is the instantaneous roll attitude rotation matrix of the inertial measurement unit, R M is the placement angle rotation matrix of the laser emission reference center and the inertial unit reference center, α is the angle between the projection of the laser emission light path on the XOY plane of the body coordinate system and the positive direction of the X axis, β is the angle between the laser emission light path and its projection line on the XOY plane, and ρ is the slant distance.

[0052] in:

[0053]

[0054]

[0055]

[0056]

[0057] Then, based on the above relationship, the error equation is constructed with the principle of minimizing the distance residual from the laser emission center to the ground reflection mark in the three-dimensional direction (slant distance).

[0058] Specifically, the equation is formulated based on the principle of minimizing the three-dimensional residual error from the laser emission center to the true coordinates of the ground reflection mark:

[0059]

[0060]

[0061]

[0062] Substitute the initial values ​​of the angle α0, β0 and the coordinates of the ground truth point X A_GCP , Y A_GCP and Z A_GCP Generate initial distance value ρ x0 , y0 , z0 , the error equation is listed and linearized based on the principle of minimizing the three-dimensional residual error from the laser emission center to the ground reflection mark real coordinates:

[0063]

[0064]

[0065]

[0066] Next, during the adjustment, the distance between the laser emission center and the ground foot point is calculated at the same time, and the correction value of the slope distance ρ is introduced.

[0067]

[0068]

[0069]

[0070] Then use the indirect adjustment formula to perform the least squares adjustment. According to the conditional formula V = AX-L, the error equation can be listed:

[0071]

[0072] in, is the distance residual of the slant range ρ, ρ x , y , z are the components of the slant distance in the x, y, and z directions in the WGS-84 spatial rectangular coordinate system, ρ x0 , y0 , z0 They are ρ x , y , z The initial value of is the coordinate of the i-th reflection mark in the WGS-84 space rectangular coordinate system, is the coordinate of the antenna phase center corresponding to the i-th reflector in the WGS-84 space rectangular coordinate system, [ΔX Ai_IMU ΔY Ai_IMU ΔZ Ai_IMU ] T is the linear offset between the laser emission reference center corresponding to the i-th reflective mark and the inertial unit reference center, R wgs84is the transformation matrix from the Northwest High coordinate system to the WGS-84 space rectangular coordinate system; R ENU is the transformation matrix from the north-eastern coordinate system to the north-west coordinate system; R H is the instantaneous azimuth attitude rotation matrix of the inertial measurement unit; R P is the instantaneous pitch attitude rotation matrix of the inertial measurement unit; R R is the instantaneous roll attitude angle rotation matrix of the inertial measurement unit, R M is the placement angle rotation matrix between the laser emission reference center and the inertial unit reference center, ω, κ is the azimuth attitude angle, pitch attitude angle and roll attitude angle respectively, α is the angle between the projection of the laser emission light path on the XOY plane of the body coordinate system and the positive direction of the X axis, β is the angle between the laser emission light path and its projection line on the XOY plane, dω, dκ are ω, The correction value of κ, dρ is the correction value of the distance residual corresponding to ρ, They are ρ x , y , z Yes The partial derivative of κ.

[0073] According to the least squares indirect adjustment principle, the above error equation is converted into the normal equation:

[0074] (A T PA)X=A T PL

[0075] Where P is the unit weight matrix of the observation value;

[0076]

[0077]

[0078]

[0079] List expressions for the solutions to the normal equation:

[0080]

[0081] In operation S106, an error equation is solved to obtain a systematic error of the installation angle of the UAV-borne radar, and the installation angle is geometrically corrected using the systematic error of the installation angle.

[0082] In the embodiment of the present invention, the error equation can be solved by iterative solution to obtain a value less than a preset threshold. The corresponding dω, dκ and dρ are the systematic errors of the installation angle.

[0083] Specifically, first, determine dω, Substitute the initial values ​​of dκ and dρ into the expression of the solution of the normal equation to solve the X matrix.

[0084] Then, substitute the X matrix into the error equation to get the residual vector matrix

[0085] Next, determine the residual vector matrix Is it greater than the preset threshold? If it is less than the preset threshold, the currently solved dω, dκ and dρ are respectively added to the ω and κ, ρ are used as the placement angle after geometric correction. If it is greater than the preset threshold, according to: ω′=ω+dω, κ′=κ+dκ、ρ′=ρ+dρ, respectively added to the ω, κ, ρ to update the new ω′, κ′, ρ′, and the new ω′, κ′ and ρ′ are used as initial values, and the residual vector matrix is ​​recalculated This iteration continues until the residual vector matrix If it is less than the preset threshold, the iteration is stopped and the currently calculated dω, dκ and dρ are respectively added to the parameters ω and κ and ρ are the installation angles after geometric correction.

[0086] To sum up, the geometric correction method for the placement error of the unmanned aerial vehicle radar provided by the present invention, by deploying multiple ground control points, taking the ground reflection mark as the geometric control point, constructs the error equation corresponding to the placement angle error of the unmanned aerial vehicle radar based on the principle of minimum residual error of the distance from the laser radar emission point to the ground geometric control point, and solves the system error parameters of the placement angle by the least squares iterative calculation method, which can achieve the optimal solution of the airborne laser radar placement error, thereby improving the three-dimensional accuracy of the laser radar point cloud, and ultimately improving the accuracy of the application of point cloud data in other aspects.

[0087] The embodiment of the present invention further provides a geometric correction device for the placement error of a radar mounted on a drone, comprising:

[0088] The deployment module is used to deploy multiple reflective markers in the calibration field and to deploy reference points and checkpoints outside the calibration field.

[0089] The first acquisition module is used to acquire the coordinates of each reflective mark based on the reference point and the check point.

[0090] The second acquisition module is used to control the UAV equipped with the laser radar to fly back and forth along a preset route passing through multiple reflective markers to obtain the attitude information and position information of the UAV.

[0091] The third acquisition module is used to obtain the slant distance and beam splitting angle from the laser radar emission point to the ground reflection point.

[0092] The building module is used to build the error equation based on the position offset and rotation geometry relationship between the laser radar and the integrated navigation system, according to the coordinates, slant range, beam splitting angle, attitude information and position information of the reflector.

[0093] The calculation module is used to solve the error equation to obtain the systematic error of the installation angle of the UAV-mounted radar; the correction module is used to perform geometric correction on the installation angle using the systematic error of the installation angle.

[0094] It should be noted that the specific implementation details and technical effects brought about by the device embodiment part and the method embodiment part provided in the embodiments of the present invention are similar. The device embodiment part can refer to the method embodiment part and will not be repeated here.

[0095] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present invention may be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments of the present invention may be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All of these combinations and / or combinations fall within the scope of the present invention.

[0096] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A geometric correction method for the placement error of an unmanned aerial vehicle radar, comprising: Arrange a plurality of reflective markers in the calibration field, and arrange reference points and check points outside the calibration field; Acquire the coordinates of each reflective marker based on the reference point and the check point; Controlling a drone equipped with a laser radar to fly back and forth along a preset route passing through the multiple reflective markers to obtain attitude information and position information of the drone; Obtaining the slant distance and beam splitting angle from the laser radar emission point to the ground reflection point; Based on the position offset and rotational geometric relationship between the laser radar and the integrated navigation system, an error equation is constructed according to the coordinates of the reflective mark, the slant range, the beam splitting angle, the attitude information and the position information; Solving the error equation, the system error of the UAV-mounted radar installation angle is obtained; Performing geometric correction on the installation angle using a systematic error of the installation angle; Wherein, the error equation is: in: ； ； ； in, , , The slope distance The distance residual, , , are the components of the slant distance in the x, y, and z directions in the WGS-84 spatial rectangular coordinate system, , , They are , , The initial value of is the coordinate of the i-th reflection mark in the WGS-84 space rectangular coordinate system, is the coordinate of the antenna phase center corresponding to the i-th reflection mark in the WGS-84 space rectangular coordinate system, is the linear offset between the laser emission reference center corresponding to the i-th reflective mark and the inertial unit reference center, It is the transformation matrix from the Northwest High coordinate system to the WGS-84 space rectangular coordinate system; is the transformation matrix from the north-eastern coordinate system to the north-west coordinate system; is the instantaneous azimuth attitude rotation matrix of the inertial measurement unit; is the instantaneous pitch attitude angle rotation matrix of the inertial measurement unit; is the instantaneous roll attitude angle rotation matrix of the inertial measurement unit, is the placement angle rotation matrix between the laser emission reference center and the inertial unit reference center, , , They are azimuth attitude angle, pitch attitude angle and roll attitude angle, is the angle between the projection of the laser emission light path on the XOY plane of the body coordinate system and the positive direction of the X axis, is the angle between the laser emission light path and its projection line on the XOY plane, , , They are , , The correction value of for The corresponding correction value of the distance residual.

2. The geometric correction method for the placement error of the UAV-mounted radar according to claim 1, wherein: The acquiring the coordinates of each reflective mark based on the reference point and the check point comprises: The reference point is used as the measuring station, the check point is used as the orientation point, and the coordinates of each reflective mark are respectively obtained using a total station.

3. The geometric correction method for the placement error of the UAV-mounted radar according to claim 1, wherein: The step of obtaining the attitude information and position information of the drone includes: Setting up a GPS base station at the reference point; The reference point is used as a base station, and GPS post-differentiation is used to perform combined navigation solution to obtain the attitude information and the position information.

4. The geometric correction method for the placement error of the unmanned aerial vehicle radar according to claim 1, wherein: The constructing of a geometric verification model based on the position offset and rotational geometric relationship between the laser radar and the integrated navigation system according to the slant range, the beam splitting angle, the attitude information and the position information comprises: The error equation is constructed based on the principle that the distance residual of the slope distance is minimized.

5. The geometric correction method for the placement error of the UAV-mounted radar according to claim 1, wherein: The systematic error of the UAV-borne radar installation angle obtained by solving the error equation includes: Solve the problem that the , , Corresponding , , , as the systematic error of the installation angle.

6. The geometric correction method for the placement error of the UAV-mounted radar according to claim 5, wherein: The error equation is solved by an iterative solution method.

7. The geometric correction method for the placement error of the UAV-mounted radar according to claim 6, wherein: The geometric correction of the installation angle by using the system error of the installation angle comprises: The currently solved , , , Add them to the previous solution , , , As the installation angle after geometric correction.

8. A geometric correction device for the placement error of an unmanned aerial vehicle radar, comprising: A deployment module, used to deploy multiple reflective markers in the calibration field, and to deploy reference points and checkpoints outside the calibration field; A first acquisition module, configured to acquire the coordinates of each reflective mark based on the reference point and the check point; A second acquisition module is used to control the drone equipped with the laser radar to fly back and forth along a preset route passing through the multiple reflective markers to acquire the attitude information and position information of the drone; A third acquisition module is used to obtain the slant distance and beam splitting angle from the laser radar emission point to the ground reflection point; A construction module, for constructing an error equation based on the position offset and rotational geometric relationship between the laser radar and the integrated navigation system, according to the coordinates of the reflection mark, the slant range, the beam splitting angle, the attitude information and the position information; A calculation module, used to solve the error equation to obtain the system error of the installation angle of the UAV-mounted radar; A correction module, used for geometrically correcting the installation angle using a systematic error of the installation angle; Wherein, the error equation is: in: ； ； ； in, , , The slope distance The distance residual, , , are the components of the slant distance in the x, y, and z directions in the WGS-84 spatial rectangular coordinate system, , , They are , , The initial value of is the coordinate of the i-th reflection mark in the WGS-84 space rectangular coordinate system, is the coordinate of the antenna phase center corresponding to the i-th reflection mark in the WGS-84 space rectangular coordinate system, is the linear offset between the laser emission reference center corresponding to the i-th reflective mark and the inertial unit reference center, It is the transformation matrix from the Northwest High coordinate system to the WGS-84 space rectangular coordinate system; is the transformation matrix from the north-eastern coordinate system to the north-west coordinate system; is the instantaneous azimuth attitude rotation matrix of the inertial measurement unit; is the instantaneous pitch attitude angle rotation matrix of the inertial measurement unit; is the instantaneous roll attitude angle rotation matrix of the inertial measurement unit, is the placement angle rotation matrix between the laser emission reference center and the inertial unit reference center, , , They are azimuth attitude angle, pitch attitude angle and roll attitude angle, is the angle between the projection of the laser emission light path on the XOY plane of the body coordinate system and the positive direction of the X axis, is the angle between the laser emission light path and its projection line on the XOY plane, , , They are , , The correction value of for The corresponding correction value of the distance residual.

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