Radiation source intersection positioning method based on multi-station array optimization

Abstract

The application discloses a radiation source intersection positioning method based on multi-station array optimization. The method firstly performs preliminary positioning, and the result after the preliminary positioning is used to determine a small space block. Then, the optimal array corresponding to the small space block is selected by comparing the geometric dilution degree of different arrays, and a relationship equation of the observation station position and the target position of the array is established, so that the target position with higher precision is obtained. The application can realize rapid positioning in a wider area, and can also improve the positioning precision in some areas.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electromagnetic radiation signal processing, and particularly relates to a radiation source intersection positioning method based on multi-station array optimization. BACKGROUND

[0002] Passive positioning technology is a technology for realizing target positioning by using electromagnetic wave signals emitted by the target. Since a passive positioning system only receives but does not emit electromagnetic wave signals to the outside world, it has the characteristics of high concealment and long detection range. In particular, a double-station intersection positioning system is widely used in the reconnaissance field due to its simple preparation, low cost, and good positioning accuracy.

[0003] A double-station intersection positioning technology obtains the azimuth information of a target by using reconnaissance equipment distributed at two observation stations to receive signals intentionally or unintentionally radiated or reflected by the target. The technology forms an intersection point according to the distribution information of the observation stations and the azimuth information obtained by detection to determine the position of the target.

[0004] In actual engineering applications, when the included angle formed by the line connecting the target and the observation station and the line connecting the two stations is small, the positioning effect of the double-station intersection positioning is poor. A part of the space of the area of interest is often in such a poor positioning effect area. In addition, when the included angle between the direction-finding baseline and the line connecting the station to the target is small, the direction-finding result is poor, which further affects the positioning accuracy. SUMMARY

[0005] The purpose of the present application is to overcome the defects of the prior art and provide a radiation source intersection positioning method based on multi-station array optimization, which realizes a positioning method with higher accuracy, higher stability, and a wider area with smaller computing resources.

[0006] The purpose of the present application is achieved by the following technical solutions:

[0007] A radiation source intersection positioning method based on multi-station array optimization, the method comprising:

[0008] Obtaining the time, frequency, and azimuth of the received signal measured by each observation station to form a detection result;

[0009] Matching the corresponding information of other stations according to the detection result, and when all stations satisfy the matching condition, combining the matched detection results into a frame structure required for positioning;

[0010] Extracting the azimuth information in the detection result of each station, selecting two observation points as preliminary positioning stations, and establishing a relationship equation of the preliminary positioning stations and the target;

[0011] Solving the relationship equation to obtain an initial estimate of the target position;

[0012] Extract the location information of each station and combine them into pairs to form different arrays. Calculate the geometric dilution of bi-station direction finding and intersection positioning within a specific scene range. Divide the scene space into multiple small spatial blocks and determine the optimal array for each small spatial block based on the geometric dilution.

[0013] Based on the initial estimate, determine the small spatial block where the target is located and select the optimal formation of the small spatial block;

[0014] Construct the relationship equation between the selected observation stations and the target, and solve it to obtain the updated final location estimate of the detected target.

[0015] Furthermore, the method further includes the following steps before the step of extracting the azimuth information from the detection results of each station:

[0016] The location information of each observation station is converted into coordinates in the Earth-fixed geocentric coordinate system, and then converted into coordinates in the Northeast-Sky coordinate system with the center of each station as the origin.

[0017] Furthermore, the relational equation includes:

[0018]

[0019] Wherein, the target position s = [xy], the position of station S1 s1 = [x1 y1], the position of station S2 s2 = [x2 y2], θ1 is the azimuth angle detected by station S1 and θ2 is the azimuth angle detected by station S2.

[0020] Furthermore, solving the relational equation to obtain the initial estimate of the target position includes:

[0021] Solving the aforementioned relational equation yields an initial estimate of the target's position in the two-dimensional plane:

[0022] s = A -1 B;

[0023] in,

[0024] Furthermore, before extracting the location information of each station and combining them into pairs to form different arrays, the method also includes converting the location information of each station into coordinates in the Earth-fixed Geocentric Coordinate System, and then converting it into coordinates in the Northeast-Sky Coordinate System with the center position of each station as the origin.

[0025] Furthermore, the geometric dilution in, and These are the variances of the positioning estimation errors in the x-axis and y-axis directions, respectively.

[0026] Furthermore, when matching the corresponding information of other stations based on the detection results, the matching time is limited to a preset range.

[0027] Furthermore, when matching the corresponding information of other stations based on the detection results, the matching frequency is limited to a preset range.

[0028] Furthermore, dividing the scene space into multiple small space blocks specifically includes dividing the space into square blocks with side lengths of 100-1000m.

[0029] Furthermore, the method includes obtaining the optimal array configuration in different spatial regions in advance when the observation station is fixed.

[0030] The beneficial effects of this invention are as follows:

[0031] This invention first performs preliminary positioning, then determines the small spatial block based on the preliminary positioning results, and then selects the optimal array for the corresponding small spatial block by comparing the geometric dilution of different array types. It then establishes the relationship equation between the observation station positions and the target positions for this array type, and solves it to obtain a more accurate target position. This invention can achieve high accuracy, high stability, and wide-area positioning with relatively small computational resources. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of the radiation source intersection and positioning method based on multi-station array optimization provided in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the preferred scenario for multi-station arrays and its positioning principle in an embodiment of the present invention. Detailed Implementation

[0034] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0035] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In practical engineering applications, the positioning effect of bi-station intersection positioning is poor when the angle formed by the line connecting the target and the observation station and the line connecting the two stations is small. A portion of the area of ​​focus often falls within this region of poor positioning performance. Furthermore, when the angle between the direction-finding baseline and the line connecting the station to the target is small, the direction-finding results are poor, thus affecting the positioning accuracy.

[0037] To address the aforementioned technical problems, the following embodiments of the radiation source intersection and positioning method based on multi-station array optimization of the present invention are proposed.

[0038] Example 1

[0039] The radiation source rendezvous and localization method based on multi-station array optimization provided in this embodiment is implemented by deploying reconnaissance equipment at each observation station. Observation station {S k}, k=0,1,…,K-1.

[0040] Reference Figure 1 ,like Figure 1 The diagram shown is a schematic flowchart of the radiation source intersection and positioning method based on multi-station array optimization provided in this embodiment. The method specifically includes the following steps:

[0041] Step 1: Obtain the received signal time t by measurement. km Frequency f km and azimuth θ km Information such as k = 1, 2, ..., K represents station S. k m = 1, 2, ..., M represents the m-th measurement information (time, frequency, azimuth, etc.).

[0042] In one implementation method, in this embodiment, each station transmits the detection results in the form of a frame consisting of one direction finding result every 0.2 seconds and one detection result every 1 second (including time, frequency, and azimuth angle, etc.).

[0043] Step 2: Extract the {S} of each observation station k The detection results of k = 0, 1, ..., K-1 will be the first received station S k The detection results are stored, and then the time t in the detection results of this station is used. km Frequency f km Match the corresponding information of other stations. When multiple stations (specific stations can be selected according to actual needs) meet the matching conditions, the detection results (time, frequency, azimuth) after matching are reassembled into the frame structure required for positioning.

[0044] Matching the detection information from various observation stations requires information such as the target's frequency and the time corresponding to its azimuth. Because the arrival time of the measured target signal at each station is affected by factors such as path difference, measurement error, and differences in standard time, the time corresponding to the target's azimuth at the same measurement moment is not consistent across different observation stations. Therefore, the matching time needs to be limited to a reasonable range, which needs to be adjusted according to the actual situation. Similarly, matching conditions such as frequency also need to be limited to a matching range to improve the matching success rate.

[0045] Step 3: Extract the longitude, latitude, and altitude (B) of each observation station from the matched frame structure. k ,L k H k k = 1, 2, ..., K, and convert latitude, longitude, and altitude from the geodetic coordinate system to the geocentric coordinate system.

[0046]

[0047] Where e is the eccentricity of the ellipsoid, and N is the radius of curvature of the reference ellipsoid.

[0048]

[0049] Where a = 6,378,137.0 meters and b = 6,356,752.3142 meters.

[0050] The center position of each observation station is selected as the origin of the coordinate system, that is, the coordinates in the Earth-fixed geocentric coordinate system are selected as the origin of the coordinate system in the northeast-sky coordinate system:

[0051]

[0052] Then, using the above coordinates as the origin of the northeast celestial coordinate system, the coordinates of each observation station in the northeast celestial coordinate system are obtained after transformation:

[0053]

[0054] Reference Figure 2 ,like Figure 2 The diagram shown is a schematic diagram of the preferred multi-station array scenario and its positioning principle in this embodiment.

[0055] Step 4: Based on the target scene of interest, select observation stations S1 and S2 as initial positioning stations. Let the target position be s = [xy], the position of station S1 be s1 = [x1 y1], and the position of station S2 be s2 = [x2 y2]. Extract the azimuth angles θ1 and θ2 measured by stations S1 and S2. Based on the geometric relationship between the positions of these two observation stations and the target signal position, obtain the relationship equation between the observation station positions, the target signal position, and the detection results (azimuth angles):

[0056]

[0057] Step 5: Solve the above equations to obtain the initial estimate of the target's position in the two-dimensional plane:

[0058] s = A -1 b;

[0059] in,

[0060] Step Six: Using the steps described above, obtain the coordinates (x, y) of each observation station in the Northeast Celestial Coordinate System (with their center position as the origin). k ,y k ,z k ), k=1,2,…K, and then observe station {S k}, k=0,1,…,K-1 combined into For different array configurations, the geometric dilution of bistatic intersection positioning (BSO) within a specific scene range is calculated for each configuration. For a two-dimensional plane, the geometric dilution of positioning accuracy for a particular array configuration is:

[0061]

[0062] Where tr(·) represents the trace of the matrix, and Let P be the variance of the positioning estimation error in the x-axis and y-axis directions, respectively. The positioning error covariance matrix P can be obtained through the error equation.

[0063] The space within the scene of interest is uniformly divided along both the x-axis and y-axis, resulting in multiple small spatial blocks. ij Where i = 1, 2, ..., I, I is the total number of uniform divisions along the x-axis, and j = 1, 2, ..., J, J is the total number of uniform divisions along the y-axis. Calculate the different array configurations in the small spatial block. i j The magnitude of geometric dilution.

[0064] Compare the different array formations formed by the combination of various observation stations in each small spatial block. ij The geometric dilution factor is used to determine the formation with the lowest GDOP among all formations, and this is applied to each small space block. ij Fill in the optimal formation with a label and create a table for use in subsequent procedures.

[0065] For fixed observation stations, the geometric dilution of array formations composed of different stations is constant. The optimal array formations in different spatial regions can be pre-prepared into tables and imported into the implementation program, thus enabling rapid and high-precision positioning. Furthermore, since the selection of the optimal array formation does not require real-time implementation, the space can be divided into finer spatial blocks (up to square blocks with side lengths of 100–1000 meters) based on existing information from various observation stations. This will more precisely characterize the distribution of the optimal array formation throughout the area of ​​interest.

[0066] The initial estimate of the target's position s in the two-dimensional plane is obtained from the aforementioned steps, and the small spatial block in which the initial estimate is located is determined. I1 and J1 are the markers along the x and y axes, respectively, where the initial estimated target position falls within the segmented small spatial blocks. Within the small spatial blocks... The optimal formation marked in the prepared table (i.e. the formation with the lowest geometric dilution) will be used as the formation for positioning.

[0067] Based on the selected formation, set the observation station S of the new formation. new1 Position s new1 =[x new1 y new1 ] and site S new2 Position s new =[x new2 y new2 Extracting observation station S. new1 The measured azimuth angle θ new1 and site S new2 The measured azimuth angle θ new2 The updated position estimate of the target signal is obtained by solving the geometric relationship between the observation station locations of the new array and the target signal location:

[0068]

[0069] in,

[0070] The radiation source intersection positioning method based on multi-station array optimization provided in this embodiment first performs preliminary positioning, then determines the optimal array, and finally performs higher-precision positioning. The results of the preliminary positioning are used to determine the small spatial block in which the target is located. Then, by comparing the geometric dilution of different arrays, the optimal array for the corresponding small spatial block is selected, and the relationship equation between the observation station position and the target position of the array is established. Solving the equation yields a more accurate target position.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A radiation source intersection and positioning method based on multi-station array optimization, characterized in that, The method includes: The detection results are generated by acquiring the time, frequency, and azimuth of the received signals measured at each observation station. Based on the detection results, match the corresponding information of other stations. When all stations meet the matching conditions, combine the matched detection results into the frame structure required for positioning. The azimuth information of each station's detection results is extracted, and two observation points are selected as preliminary positioning stations. The relationship equation between the preliminary positioning stations and the target is established. Solving the relational equation yields an initial estimate of the target location; Extract the location information of each station and combine them into pairs to form different arrays. Calculate the geometric dilution of bi-station direction finding and intersection positioning within a specific scene range. Divide the scene space into multiple small spatial blocks and determine the optimal array for each small spatial block based on the geometric dilution. Based on the initial estimate, determine the small spatial block where the target is located and select the optimal formation of the small spatial block; Construct the relationship equation between the selected observation stations and the target, and solve it to obtain the updated final location estimate of the detected target.

2. The radiation source intersection and positioning method based on multi-station array optimization as described in claim 1, characterized in that, The method further includes the following steps before the step of extracting azimuth information from the detection results of each station: The location information of each observation station is converted into coordinates in the Earth-fixed geocentric coordinate system, and then converted into coordinates in the Northeast-Sky coordinate system with the center of each station as the origin.

3. The radiation source intersection and positioning method based on multi-station array optimization as described in claim 2, characterized in that, The relational equations include: Wherein, the target position s = [xy], the position of station S1 s1 = [x1 y1], the position of station S2 s2 = [x2 y2], θ1 is the azimuth angle detected by station S1 and θ2 is the azimuth angle detected by station S2.

4. The radiation source intersection and positioning method based on multi-station array optimization as described in claim 3, characterized in that, The process of solving the relational equation to obtain the initial estimate of the target position includes: Solving the aforementioned relational equation yields an initial estimate of the target's position in the two-dimensional plane: s=A -1 B; in, 5. The radiation source intersection and positioning method based on multi-station array optimization as described in claim 2, characterized in that, Before extracting the location information of each station and combining them into pairs to form different arrays, the method also includes converting the location information of each station into coordinates in the Earth-fixed Geocentric Coordinate System, and then converting it into coordinates in the Northeast-Sky Coordinate System with the center position of each station as the origin.

6. The radiation source intersection and positioning method based on multi-station array optimization as described in claim 3, characterized in that, Geometric dilution in, and These are the variances of the positioning estimation errors in the x-axis and y-axis directions, respectively.

7. The radiation source intersection and positioning method based on multi-station array optimization as described in claim 1, characterized in that, When matching the corresponding information of other stations based on the detection results, the matching time is limited to a preset range.

8. The radiation source intersection and positioning method based on multi-station array optimization as described in claim 1, characterized in that, When matching the corresponding information of other stations based on the detection results, the matching frequency is limited to a preset range.

9. The radiation source intersection and positioning method based on multi-station array optimization as described in claim 1, characterized in that, The division of the scene space into multiple small space blocks specifically includes dividing the space into square blocks with side lengths of 100-1000m.

10. The radiation source intersection and positioning method based on multi-station array optimization as described in claim 1, characterized in that, The method includes obtaining the optimal array configuration in different spatial regions in advance when the observation station is fixed.

Images