Unmanned aerial vehicle aeromagnetic measurement real-time inversion method and system

Abstract

The invention provides a real-time inversion method and system for aeromagnetic measurement of an unmanned aerial vehicle, and relates to the field of geophysics, and the method comprises the steps: carrying out the mesh generation of an underground space of a target region, and obtaining all subdivided meshes; calculating a weighting matrix for inversion according to the position information of the subdivision grid; acquiring aeromagnetic data of the current observation point in real time and preprocessing the aeromagnetic data to obtain magnetic anomaly data; calculating a kernel vector according to the position information of the current observation point; incorporating the kernel vector into a kernel matrix; determining an initial model of a current observation point through a real-time inversion magnetic body model obtained at a previous observation point; and performing real-time inversion through the initial model, the weighting matrix and the kernel matrix to obtain a real-time inversion magnetic body model of the current observation point, and performing visual display to complete the real-time imaging of the magnetic distribution result of the underground space. According to the technical scheme of the invention, the method achieves the real-time and rapid inversion function under the condition of guaranteeing the inversion accuracy.

Description

Technical Field

[0001] The present application relates to the field of geophysics, and in particular to a real-time inversion method and system for unmanned aerial vehicle aeromagnetic measurement. Background Art

[0002] UAV aeromagnetic survey is a fast, efficient and economical geophysical exploration method. The aeromagnetic data obtained by UAV measurement can be used to invert magnetic anomalies and obtain the distribution of magnetic field sources, which is of great significance for the detection and positioning of hidden targets.

[0003] During inversion, the underground space is divided into several discrete units. It is assumed that the magnetization intensity or magnetic susceptibility of each discrete unit is uniform. The kernel matrix is ​​calculated, and the observed magnetic anomaly data is input. The magnetization intensity or magnetic susceptibility distribution of the underground space can be calculated through inversion.

[0004] At present, aeromagnetic anomaly inversion is usually carried out after the aircraft aeromagnetic survey is completed. Data measurement and data inversion are carried out independently, which leads to the inability to timely evaluate the aeromagnetic anomaly observation results and obtain inversion results in real time, which is not conducive to improving detection efficiency and accuracy. Summary of the invention

[0005] The purpose of the present invention is to provide a real-time inversion method and system for UAV aeromagnetic measurement in order to solve the problem that the existing aeromagnetic anomaly inversion method is difficult to perform real-time inversion of measured aeromagnetic data and cannot take into account both detection efficiency and detection accuracy.

[0006] The above-mentioned purpose of the present application is achieved through the following technical solutions: S1: Grid the underground space of the target area to obtain grids; S2: Calculate the weight matrix used for inversion based on the position information of the subdivided grid; S3: Acquire the aeromagnetic data of the current observation point in real time and perform preprocessing to obtain magnetic anomaly data; S4: Calculate the kernel vector according to the position information of the current observation point; merge the kernel vector into the kernel matrix; S5: Determine the initial model of the current observation point through the real-time inversion magnetic body model obtained from the previous observation point; perform real-time inversion through the initial model, weighted matrix and kernel matrix to obtain the real-time inversion magnetic body model of the current observation point and display it visually, completing the real-time imaging of the magnetic distribution results of the underground space.

[0007] Optionally, step S3 includes: Preprocessing includes compensation, correction and filtering.

[0008] Optionally, step S4 includes: The kernel matrix is ​​as follows:

[0009] In the formula For the The kernel matrix of the real-time inversion of observation points, The observation point is the current observation point; For the The kernel matrix of the real-time inversion of observation points, The observation point is the previous observation point; For the The kernel vector of real-time inversion of each observation point is used to calculate the magnetic anomaly response of the grid with unit magnetization intensity or magnetic susceptibility to the current observation point.

[0010] Optionally, step S5 includes: S51: Set The initial model for each observation point is , Equal to Real-time inversion of magnetic body model at each observation point times, that is ,in ; S52: Using the initial model And the kernel matrix is ​​inverted in real time to obtain the Real-time inversion magnetic body model of each observation point; S53: Visualize the real-time inversion magnetic body model to complete the real-time imaging of the magnetic distribution results of the underground space.

[0011] Optionally, step S52 includes: S52a: Set ;like ,but ,otherwise ; S52b: Calculation ,in represents aeromagnetic observation data, Indicates The fitted data after iterations, Indicates The data residual after iterations; S52c: If Less than the preset error , then output the optimal solution , and obtain the real-time inversion magnetic body model; like , then execute step S52d; S52d: Order ,in Indicates The model increment of the iteration; S52e: Order ,in represents the weighted iteration direction, represents the weighting matrix used for inversion, ;like , then let , otherwise let , , represents the iteration step length; S52f: Order

[0012]

[0013]

[0014]

[0015] in represents the intermediate variable of the iterative process, represents the iteration step length; S52g: If Less than the preset error , execute step S52h; like , then let , execute step S52e; S52h: ,right Apply upper and lower bound constraints, i.e. , The distribution represents the minimum and maximum values ​​of the upper and lower bounds; make , execute step S52b.

[0016] A real-time inversion system for UAV aeromagnetic measurement, the system comprising: a data acquisition module, a data preprocessing module, an inversion module and a display module; The data acquisition module, the data preprocessing module, the inversion module and the display module are connected in sequence; The data acquisition module is used to obtain the aeromagnetic data of the current observation point in real time; The data preprocessing module is used to preprocess the aeromagnetic data to obtain magnetic anomaly data; The inversion module is used to grid the underground space of the target area to obtain each grid; The inversion module is also used to calculate a weighted matrix for inversion according to the position information of the subdivided grid; The inversion module is also used to calculate the kernel vector according to the position information of the current observation point; and incorporate the kernel vector into the kernel matrix; The inversion module is also used to determine the initial model of the current observation point through the real-time inversion magnetic body model obtained at the previous observation point; perform real-time inversion through the initial model, weighted matrix and kernel matrix to obtain the real-time inversion magnetic body model of the current observation point; The display module is used to visualize the real-time inversion magnetic body model and complete the real-time imaging of the magnetic distribution results of the underground space.

[0017] Optionally, the data acquisition module includes: a drone and a magnetometer; The magnetometer is arranged on the drone; The magnetometer is used to obtain aeromagnetic data of the current observation point.

[0018] A computer-readable storage medium stores instructions. When the instructions are executed, a real-time inversion method for unmanned aerial vehicle aeromagnetic measurement is performed.

[0019] The beneficial effects of the technical solution provided by this application are: The present invention proposes a method for real-time inversion during the aeromagnetic measurement of a UAV. When the aeromagnetic system of the UAV completes the aeromagnetic data measurement of a measuring point, the kernel matrix is ​​immediately updated through the aeromagnetic data, and then the real-time inversion model after the observation of the previous measuring point is used as the initial model for iterative inversion, so as to obtain the real-time inversion magnetic body model of the current measuring point and perform visual display, so as to perform real-time evaluation on the magnetic anomaly observation results and improve the efficiency and accuracy of the aeromagnetic detection of the UAV. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present application will be further described below with reference to the accompanying drawings and embodiments, in which: Figure 1 is a flow chart in an embodiment of the present application; Figure 2 is a system module diagram in an embodiment of the present application; Figure 3 is a magnetization intensity distribution diagram in an embodiment of the present application; Figure 4 This is a real-time inversion result diagram of the 10th data in the embodiment of the present application; Figure 5 This is a real-time inversion result diagram of the 20th data in the embodiment of the present application; Figure 6 This is a real-time inversion result diagram of the 30th data in the embodiment of the present application; Figure 7 This is a real-time inversion result diagram of the 40th data in the embodiment of the present application; Figure 8 This is a real-time inversion result diagram of the 50th data in the embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation methods of the present application are now described in detail with reference to the accompanying drawings.

[0022] An embodiment of the present application provides a real-time inversion method for unmanned aerial vehicle aeromagnetic measurement.

[0023] Please refer to Figure 1 , Figure 1 : is a flow chart of a real-time inversion method for UAV aeromagnetic measurement in an embodiment of the present application, comprising: S1: Grid the underground space of the target area to obtain grids; S2: Calculate the weight matrix used for inversion based on the position information of the subdivided grid; S3: Acquire the aeromagnetic data of the current observation point in real time and perform preprocessing to obtain magnetic anomaly data; Step S3 includes: Preprocessing includes compensation, correction and filtering.

[0024] As an embodiment, aeromagnetic data of an observation point is collected by using a drone, and the aeromagnetic data is sequentially input into a compensation system, a correction system, and a filtering system to obtain corrected magnetic anomaly data.

[0025] S4: Calculate the kernel vector according to the position information of the current observation point; merge the kernel vector into the kernel matrix; Step S4 includes: The kernel matrix is ​​as follows:

[0026] In the formula For the The kernel matrix of the real-time inversion of observation points, The observation point is the current observation point; For the The kernel matrix of the real-time inversion of observation points, The observation point is the previous observation point; For the The kernel vector of real-time inversion of each observation point is used to calculate the magnetic anomaly response of the grid with unit magnetization intensity or magnetic susceptibility to the current observation point.

[0027] S5: Determine the initial model of the current observation point through the real-time inversion magnetic body model obtained from the previous observation point; perform real-time inversion through the initial model, weighted matrix and kernel matrix to obtain the real-time inversion magnetic body model of the current observation point and display it visually, completing the real-time imaging of the magnetic distribution results of the underground space.

[0028] Step S5 includes: S51: Set The initial model of the observation point is , Equal to Real-time inversion of magnetic body model at each observation point times, that is ,in ; S52: Using the initial model And the kernel matrix is ​​inverted in real time to obtain the Real-time inversion magnetic body model of each observation point; Step S52 includes: S52a: Set ;like ,but ,otherwise ; S52b: Calculation ,in represents aeromagnetic observation data, Indicates The fitted data after iterations, Indicates The data residual after iterations; S52c: If Less than the preset error , then output the optimal solution , and obtain the real-time inversion magnetic body model; like , then execute step S52d; S52d: Order ,in Indicates The model increment of the iteration; S52e: Order ,in represents the weighted iteration direction, represents the weighting matrix used for inversion, ;like , then let , otherwise let , , represents the iteration step length; S52f: Order

[0029]

[0030]

[0031]

[0032] in represents the intermediate variable of the iterative process, represents the iteration step length; S52g: If Less than the preset error , execute step S52h; like , then let , execute step S52e; S52h: ,right Apply upper and lower bound constraints, i.e. , The distribution represents the minimum and maximum values ​​of the upper and lower bounds; make , execute step S52b.

[0033] S53: Visualize the real-time inversion magnetic body model to complete the real-time imaging of the magnetic distribution results of the underground space.

[0034] Please refer to Figure 2 , Figure 2 It is a module diagram of a real-time inversion system for UAV aeromagnetic measurement in an embodiment of the present application, wherein the system comprises: a data acquisition module, a data preprocessing module, an inversion module and a display module; The data acquisition module, the data preprocessing module, the inversion module and the display module are connected in sequence; The data acquisition module is used to obtain the aeromagnetic data of the current observation point in real time; The data preprocessing module is used to preprocess the aeromagnetic data to obtain magnetic anomaly data; The inversion module is used to grid the underground space of the target area to obtain each grid; The inversion module is also used to calculate a weighted matrix for inversion according to the position information of the subdivided grid; The inversion module is also used to calculate the kernel vector according to the position information of the current observation point; and incorporate the kernel vector into the kernel matrix; The inversion module is also used to determine the initial model of the current observation point through the real-time inversion magnetic body model obtained at the previous observation point; perform real-time inversion through the initial model, weighted matrix and kernel matrix to obtain the real-time inversion magnetic body model of the current observation point; The display module is used to visualize the real-time inversion magnetic body model and complete the real-time imaging of the magnetic distribution results of the underground space.

[0035] The data acquisition module includes: a drone and a magnetometer; The magnetometer is arranged on the drone; The magnetometer is used to obtain aeromagnetic data of the current observation point.

[0036] As an example, suppose the total number of drone aeromagnetic observation points is , the measurement interval is 20 m, and the total length of the required measurement profile is 1000 m. The specific steps of real-time inversion are: Step 1: Divide the underground space into 50 × 25 = 1250 rectangular grid units. The size of each rectangle is 20 m × 20 m. ; Step 2: Using the location information of the mesh , calculate the weight matrix P:

[0037] Where C is a constant used to adjust the weight matrix value. is the magnetic anomaly decay rate constant; Represents the identity matrix.

[0038] Step 3: Acquire the aeromagnetic data of the current observation point in real time and preprocess it to obtain magnetic anomaly data; calculate the kernel vector according to the position information of the current observation point; and incorporate the kernel vector into the kernel matrix; Step 4: Set the current Initial model at observation points Equal to the previous real-time inversion result times, that is , Take 0.9, if at this time ,Pick Using the initial model Constrain the previous real-time inversion result and calculate the smooth solution of the model The maximum number of iterations is set to 20, and the allowable error and Set to 0.001 and 0.01, set the maximum allowed magnetization intensity to 100 A / m and the minimum to 0 A / m.

[0039] Step 5: Display real-time inversion results ,make And return to step 3.

[0040] As an example, Figure 3 is the distribution diagram of the real magnetization intensity; Figure 4 Measure the 10th data for the drone ( = 200 m) after compensation, correction and filtering of total field measurement data and real-time inversion results; Figure 5 Measure the 20th data for the drone ( = 400 m) after compensation, correction and filtering of total field measurement data and real-time inversion results; Figure 6 Measure the 30th data for the drone ( = 600 m) after compensation, correction and filtering of total field measurement data and real-time inversion results; Figure 7 Measure the 40th data for the drone ( = 800 m) after compensation, correction and filtering of total field measurement data and real-time inversion results; Figure 8 When the drone measurement is completed (the 50th data, = 1000 m) total field measurement data after compensation, correction and filtering and the result of real-time inversion; the present invention can perform real-time magnetic anomaly inversion based on the observed magnetic anomaly data.

[0041] As an example, Figure 5 As shown, when the drone measurement data is incomplete but has a certain amount, the method of this patent invention can obtain an inversion result close to the real geological model. It can be seen that the real-time inversion method of drone aeromagnetic anomaly data in this application realizes the function of real-time rapid inversion while ensuring the accuracy of inversion, which is conducive to real-time evaluation of drone-observed magnetic anomalies, and real-time adjustment and optimization of drone observation systems, thereby improving the efficiency and accuracy of drone aeromagnetic detection.

[0042] The present application also discloses a computer-readable storage medium storing a plurality of instructions suitable for loading by a processor to execute the above-mentioned real-time inversion method for unmanned aerial vehicle aeromagnetic measurement.

[0043] The above are only exemplary embodiments of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure.

[0044] This application is intended to cover any variation, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art not described in the present disclosure. The description and examples are to be regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A real-time inversion method for UAV aeromagnetic measurement, characterized in that: The method comprises the following steps: S1: Grid the underground space of the target area to obtain grids; S2: Calculate the weight matrix used for inversion based on the position information of the subdivided grid; S3: Acquire the aeromagnetic data of the current observation point in real time and perform preprocessing to obtain magnetic anomaly data; S4: Calculate the kernel vector according to the position information of the current observation point; merge the kernel vector into the kernel matrix; S5: Determine the initial model of the current observation point through the real-time inversion magnetic body model obtained from the previous observation point; perform real-time inversion through the initial model, weighted matrix and kernel matrix to obtain the real-time inversion magnetic body model of the current observation point and display it visually, completing the real-time imaging of the magnetic distribution results of the underground space.

2. The real-time inversion method for UAV aeromagnetic measurement according to claim 1, characterized in that: Step S3 includes: Preprocessing includes compensation, correction and filtering.

3. The real-time inversion method for UAV aeromagnetic measurement according to claim 1, characterized in that: Step S4 includes: The kernel matrix is ​​as follows: In the formula For the The kernel matrix of the real-time inversion of observation points, The observation point is the current observation point; For the The kernel matrix of the real-time inversion of observation points, The observation point is the previous observation point; For the The kernel vector of real-time inversion of each observation point is used to calculate the magnetic anomaly response of the grid with unit magnetization intensity or magnetic susceptibility to the current observation point.

4. A real-time inversion method for UAV aeromagnetic measurement as claimed in claim 3, characterized in that: Step S5 includes: S51: Set The initial model for each observation point is , Equal to Real-time inversion of magnetic body model at each observation point times, that is ,in ; S52: Using the initial model And the kernel matrix is ​​inverted in real time to obtain the Real-time inversion magnetic body model of each observation point; S53: Visualize the real-time inversion magnetic body model to complete the real-time imaging of the magnetic distribution results of the underground space.

5. The real-time inversion method for UAV aeromagnetic measurement according to claim 1, characterized in that: Step S52 includes: S52a: Set ;like ,but ,otherwise ; S52b: Calculation ,in represents aeromagnetic observation data, Indicates The fitted data after iterations, Indicates The data residual after iterations; S52c: If Less than the preset error , then output the optimal solution , and obtain the real-time inversion magnetic body model; like , then execute step S52d; S52d: Order ,in Indicates The model increment of the iteration; S52e: Order ,in represents the weighted iteration direction, represents the weighting matrix used for inversion, ;like , then let , otherwise let , , represents the iteration step length; S52f: Order in represents the intermediate variable of the iterative process, represents the iteration step length; S52g: If Less than the preset error , execute step S52h; like , then let , execute step S52e; S52h: ,right Apply upper and lower bound constraints, i.e. , The distribution represents the minimum and maximum values ​​of the upper and lower bounds; make , execute step S52b.

6. A UAV aeromagnetic measurement real-time inversion system, used to implement a UAV aeromagnetic measurement real-time inversion method as claimed in any one of claims 1 to 5, characterized in that: The system comprises: a data acquisition module, a data preprocessing module, an inversion module and a display module; The data acquisition module, the data preprocessing module, the inversion module and the display module are connected in sequence; The data acquisition module is used to obtain the aeromagnetic data of the current observation point in real time; The data preprocessing module is used to preprocess the aeromagnetic data to obtain magnetic anomaly data; The inversion module is used to grid the underground space of the target area to obtain each grid; The inversion module is also used to calculate a weighted matrix for inversion according to the position information of the subdivided grid; The inversion module is also used to calculate the kernel vector according to the position information of the current observation point; and incorporate the kernel vector into the kernel matrix; The inversion module is also used to determine the initial model of the current observation point through the real-time inversion magnetic body model obtained at the previous observation point; perform real-time inversion through the initial model, weighted matrix and kernel matrix to obtain the real-time inversion magnetic body model of the current observation point; The display module is used to visualize the real-time inversion magnetic body model and complete the real-time imaging of the magnetic distribution results of the underground space.

7. The real-time inversion system for UAV aeromagnetic measurement as claimed in claim 6, characterized in that: The data acquisition module includes: a drone and a magnetometer; The magnetometer is arranged on the drone; The magnetometer is used to obtain aeromagnetic data of the current observation point.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed by a computer, the method according to any one of claims 1 to 5 is executed.

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