A Method for Locating Electromagnetic Leakage Signals by Fusing Multi-Source Information

Abstract

The present invention relates to the technical field of electromagnetic safety protection, and discloses a method for multi-source information fusion and positioning of electromagnetic leakage signals, comprising the following steps: within a selected spatial range, a user holds a single-ended detector and scans the electromagnetic leakage signals in the environment during movement, and determines the direction of the electromagnetic leakage signal source through the intensity of the electromagnetic leakage signal; collects the motion attitude information of the single-ended detector through an inertial measurement unit, and reconstructs the motion trajectory of the single-ended detector after filtering by a Kalman filter; constructs a spatial rectangular coordinate system with the initial position as the origin, selects three positions in the motion trajectory in combination with the initial position, and locates the position of the electromagnetic leakage signal by using the TDOA positioning algorithm; combines the direction of the electromagnetic leakage signal source determined during the movement process to locate the position of the electromagnetic leakage signal again. The present invention combines single-ended detection, an inertial measurement unit and the TDOA algorithm to achieve precise positioning of electromagnetic leakage signals without the support of multiple base stations.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic safety protection, and particularly to a method for multi-source information fusion and positioning of electromagnetic leakage signals. Background Art

[0002] During the operation of information devices, it is inevitable to radiate electromagnetic signals outward. If these signals contain classified information and are received and restored by other electronic devices, it will lead to the leakage of classified information and pose a huge threat to information security.

[0003] Currently, the detection and positioning methods for electromagnetic leakage signals in space can only determine the approximate area where the leakage signals are located, rather than the precise position. Therefore, how to efficiently and accurately detect whether there is electromagnetic signal leakage in space comprehensively, and how to locate the electromagnetic leakage signals to achieve targeted key protection is an urgent need for electromagnetic safety protection under the current situation. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for multi-source information fusion and positioning of electromagnetic leakage signals, which realizes the precise positioning of electromagnetic leakage signals.

[0005] In order to achieve the above invention purpose, the following technical solutions are further adopted:

[0006] A method for multi-source information fusion and positioning of electromagnetic leakage signals includes the following steps:

[0007] S1. In a selected space range, the user holds a single-ended detector and scans the electromagnetic leakage signals in the environment during movement, and determines the direction of the electromagnetic leakage signal source according to the intensity of the electromagnetic leakage signals;

[0008] S2. Collect the motion attitude information of the single-ended detector through an inertial measurement unit, and reconstruct the motion trajectory of the single-ended detector after filtering by a Kalman filter;

[0009] S3. Taking the initial position as the origin, construct a space rectangular coordinate system, select three positions in the motion trajectory and combine with the initial position, and use the TDOA positioning algorithm to locate the position of the electromagnetic leakage signal;

[0010] S4. Combine the direction of the electromagnetic leakage signal source determined during the movement process to locate the position of the electromagnetic leakage signal again.

[0011] As a further improvement of the present invention, in step S1, the direction of the electromagnetic leakage signal source is the direction when the intensity of the electromagnetic leakage signal is the largest, and the maximum intensity of the electromagnetic leakage signal is manifested as the maximum amplitude of the electromagnetic leakage signal in the time domain.

[0012] As a further improvement of the present invention, in step S2, the inertial measurement unit is an acceleration sensor and a gyroscope.

[0013] As a further improvement of the present invention, in step S3, the directions of the electromagnetic signal sources have been determined at all three positions and the position where the initial position is located.

[0014] As a further improvement of the present invention, in step S3, the TDOA positioning algorithm locates the position of the electromagnetic leakage signal in space through the coordinates of four points.

[0015] As a further improvement of the present invention, in step S3, using the TDOA positioning algorithm to locate the position of the electromagnetic leakage signal specifically includes the following steps:

[0016] S3-1. Assume that the electromagnetic leakage signal positioning system consists of 4 points, 1 point is the initial position, and the other three are positions on the movement trajectory. Taking the initial position as the origin, a space rectangular coordinate system is constructed. Then the initial position is (0, 0, 0), position 1 is (x s1 , y s1 , z s1 ), position 2 is (x s2 , y s2 , z s2 ), and position 3 is (x s3 , y s3 , z s3 );

[0017] S3-2. Measure the distance differences Δi between the target reaching the initial position and the other three positions (the distance differences are obtained by multiplying time by the speed of light). Then the corresponding equations are:

[0018]

[0019] After simplification, it can be obtained:

[0020]

[0021] This equation also holds for the sum of distances; only when Δ i is the distance difference, l i >0, and when Δ i is the sum of distances, l i <0;

[0022] S3-3. The 3 distance difference measurement values form the following non-linear equations:

[0023]

[0024] S3-4. Solve the equations to obtain the position (x', y', z') of the electromagnetic leakage signal.

[0025] As a further improvement of the present invention, in step S4, in combination with the direction of the electromagnetic leakage signal source determined during the movement process, the position of the electromagnetic leakage signal is located again, which specifically includes the following steps:

[0026] S4-1. In the established spatial rectangular coordinate system, according to the direction of the electromagnetic signal source, list the linear equations of 4 positions in the positioning system:

[0027] a1x + b1y + c1z + d1 = 0,

[0028] a2x + b2y + c2z + d2 = 0,

[0029] a3x + b3y + c3z + d3 = 0,

[0030] a4x + b4y + c4z + d4 = 0;

[0031] S4-2. Combine the above equations into 4 different systems of equations respectively, and N (N≤4) solutions can be obtained. If N≤2, use a single-ended detector to detect again, establish a new spatial rectangular coordinate system, list the system of linear equations and solve again until N>2; if N>2, calculate the average value of the obtained N solutions, and its calculation formula is as follows:

[0032]

[0033] S4-3. Combine the results of S3-4 and S4-2 to obtain the final position (x, y, z) of the electromagnetic leakage signal source:

[0034]

[0035] The beneficial effects of the present invention are as follows: The present invention combines single-ended detection, an inertial measurement unit and the TDOA algorithm to achieve the positioning of electromagnetic leakage signals without the support of multiple base stations, improving the accuracy, robustness and real-time performance of positioning, and solving the problems of how to efficiently and accurately detect whether there is electromagnetic signal leakage in space comprehensively and how to locate electromagnetic leakage signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0037] Figure 1 is the flowchart of the method of the present invention;

[0038] Figure 2 is the schematic diagram of the electromagnetic leakage signal detected by the single-ended detector;

[0039] Figure 3Schematic diagram for motion trajectory reconstruction;

[0040] Figure 4 Schematic diagram for TDOA positioning algorithm. Specific implementation manners

[0041] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0042] In order to enable those skilled in the art of this technology to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0043] As Figures 1-4 shown, a multi-source information fusion positioning electromagnetic leakage signal method based on single-ended detection and inertial measurement includes a single-ended detection positioning process, a motion trajectory reconstruction process, a TDOA algorithm positioning process, and a combined positioning process of single-ended detection and TDOA positioning algorithm.

[0044] S1. Single-ended detection positioning process, including the following steps:

[0045] S1-1. In a selected space range, the user holds a single-ended detector and scans the electromagnetic leakage signals in the environment during the movement process;

[0046] S1-2. The single-ended detector can display the intensity of the received electromagnetic signal on the screen. The intensity of the electromagnetic leakage signal is determined by the amplitude of the electromagnetic leakage signal. The direction of the received electromagnetic leakage signal is judged according to the intensity of the electromagnetic leakage signal;

[0047] S1-3. The user holds the single-ended detector and continues to move, continuously judging the direction of the electromagnetic leakage signal during the movement process, and performing a preliminary positioning on the electromagnetic leakage signal.

[0048] S2. Motion trajectory reconstruction process, including the following steps:

[0049] S2-1. Collect the acceleration and angular velocity data of the single-ended detector during the movement process through an acceleration sensor and a gyroscope;

[0050] S2-2. Use Kalman filtering to remove the noise in the collected acceleration and angular velocity data to obtain more accurate data. Substitute the filtered acceleration data into the velocity vector update equation, and we can get:

[0051] vn v(t + dt) = v(t) + a(t)×dt; n a(t) n × dt;

[0052] Where, v(t) n is the velocity vector at the current moment, a(t) is the acceleration vector at the current moment, and v(t + dt) n is the updated velocity vector;

[0053] S2-3. Use the three-axis angular velocity data for attitude estimation. The attitude estimation equation is:

[0054]

[0055] Where, C(t) i n is the attitude transformation matrix at the current moment, I is the third-order identity matrix, and B(t) is the small angle skew-symmetric matrix used to define the direction:

[0056]

[0057] Where, ωx, ωy xt and ωz yt are the three outputs of the three-axis gyroscope at time t, respectively; zt

[0058] S2.4. Use the velocity data to solve the position coordinates. The position vector update equation is:

[0059] p(t + dt) = p(t) + v(t)×dt; n n v(t) n × dt;

[0060] Where, p(t) n is the position vector at the current moment, v(t) n is the velocity vector at the current moment, and p(t + dt) n is the updated value of the position vector;

[0061] S3. The process of locating the electromagnetic leakage signal by the TDOA algorithm includes the following steps:

[0062] S3-1. Assume that the electromagnetic leakage signal positioning system consists of 4 points, 1 point is the initial position, and the other three are positions on the movement trajectory. Then the initial position is (0, 0, 0), position 1 is (x s1 , y s1 , z s1 ), position 2 is (x s2 , y s2 , z s2 ), and position 3 is (x s3 ​​, y s3 , z s3 );

[0063] S3-2. Measure the distance differences Δ i (The distance differences are obtained by multiplying time by the speed of light), then the corresponding equations are:

[0064]

[0065] Further simplification can obtain the following equations:

[0066]

[0067] These equations also hold for the sum of distances; only when Δ i is the distance difference, l i >0, and when Δ i is the sum of distances, l i <0;

[0068] S3-3. For the 3 distance difference measurement values, the following non-linear equations can be formed:

[0069]

[0070] S3-4. Solve the equations to obtain the position (x', y', z') of the electromagnetic leakage signal in space.

[0071] S4. The positioning process combining single-ended detection and the TDOA algorithm includes the following steps:

[0072] S4-1. In the constructed rectangular coordinate system in space, list the straight line equations of 4 positions in the positioning system according to the direction of the electromagnetic signal source:

[0073] a1x + b1y + c1z + d1 = 0,

[0074] a2x + b2y + c2z + d2 = 0,

[0075] a3x + b3y + c3z + d3 = 0,

[0076] a4x + b4y + c4z + d4 = 0;

[0077] S4-2. Combine the above equations into 4 different groups of equations, and N (N ≤ 4) solutions can be solved. If N ≤ 2, use the single-ended detector to detect again, construct a new rectangular coordinate system in space, list the straight line equations and solve again until N > 2; if N > 2, calculate the mean value of the N solutions obtained, and its calculation formula is as follows:

[0078]

[0079] S4-3. Combine the results of S3-4 and S4-2 to obtain the final position (x, y, z) of the electromagnetic leakage signal, and its calculation formula is as follows:

[0080]

[0081] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, component disassembly or combination, 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 locating electromagnetic leakage signals through multi-source information fusion, characterized in that It includes the following steps: S1. In a selected spatial range, the user holds a single-ended detector and scans the electromagnetic leakage signals in the environment during movement, and determines the direction of the electromagnetic leakage signal source based on the intensity of the electromagnetic leakage signals; S2. Collect the motion attitude information of the single-ended detector through an inertial measurement unit, and reconstruct the motion trajectory of the single-ended detector after filtering by a Kalman filter; S3. Taking the initial position as the origin, construct a spatial rectangular coordinate system, select three positions in the motion trajectory combined with the initial position, and use the TDOA positioning algorithm to locate the position of the electromagnetic leakage signal; In step S3, using the TDOA positioning algorithm to locate the position of the electromagnetic leakage signal specifically includes the following steps: S3-1. Suppose the electromagnetic leakage signal positioning system consists of 4 points, 1 point is the initial position, and the other three are positions on the movement trajectory. Taking the initial position as the origin, a space rectangular coordinate system is constructed. Then the initial position is (0, 0, 0), position 1 is ( x s1 ，y s1 ，z s1 ), position 2 is ( x s2 , y s2 , z s2 ), and position 3 is ( x s3 , y s3 , z s3 ); S3-2. Measure the distance differences between the target's arrival at the initial position and the other three positions Δ i , and the corresponding equation is: ； It can be simplified to: ； This equation also holds for the sum of distances; it's just that when Δ i is the difference in distances , when Δ i is the sum of distances ; S3-3. The 3 distance difference measurement values form the following non-linear equations: ； S3-4. Solve the equations to obtain the position of the electromagnetic leakage signal ( x’ , y’ , z’ ); S4. Combining the direction of the electromagnetic leakage signal source determined during the movement process, locate the position of the electromagnetic leakage signal again.

2. The method for locating an electromagnetic leakage signal by multi-source information fusion according to claim 1, characterized in that: In step S1, the direction of the electromagnetic leakage signal source is the direction when the intensity of the electromagnetic leakage signal is the largest, and the maximum of the electromagnetic leakage signal intensity is manifested as the maximum amplitude of the electromagnetic leakage signal in the time domain.

3. A method for locating electromagnetic leakage signals by multi-source information fusion according to claim 1, characterized in that: In step S2, the inertial measurement unit is an acceleration sensor and a gyroscope.

4. A method for locating electromagnetic leakage signals by fusing multi-source information according to claim 1, characterized in that: In step S3, the directions of the electromagnetic signal sources have been determined at the three positions and the initial position.

5. The method for locating an electromagnetic leakage signal by fusing multi-source information according to claim 1, characterized in that: In step S3, the TDOA positioning algorithm locates the position of the electromagnetic leakage signal in space through the coordinates of four points.

6. A method for locating electromagnetic leakage signals by multi-source information fusion according to claim 1, characterized in that, In step S4, combining the direction of the electromagnetic leakage signal source determined during the movement process, locating the position of the electromagnetic leakage signal again specifically includes the following steps: S4-1. In the constructed spatial rectangular coordinate system, list the straight line equations of the 4 positions in the positioning system according to the direction of the electromagnetic signal source; ， ， ， ； S4-2. Combine the above equations into 4 different groups of equations, and N solutions can be obtained, where N ≤ 4; if N ≤ 2, then use the single-ended detector to detect again, construct a new spatial rectangular coordinate system, list the straight line equations and solve again until N > 2; if N > 2, then calculate the mean value of the N solutions obtained, and its calculation formula is as follows: ； S4-3. Combining the results of S3-4 and S4-2 can obtain the final position (x, y, z) of the electromagnetic leakage signal source: 。

Images