A time difference extraction filtering method based on multi-station direction finding, medium and device

Abstract

This invention provides a time difference extraction and filtering method, medium, and apparatus based on multi-station direction finding. The method includes: S1, calculating and generating an angle threshold; S2, calculating and generating a direction finding angle-reception time arrangement mapping table; S3, setting a maximum positioning angle; S4, calculating a fuzzy time difference window; and S5, using the generated angle threshold, the direction finding angle-reception time arrangement mapping table, the maximum positioning angle, and the fuzzy time difference window for time difference extraction and filtering. This invention fully utilizes the deployment coordinates, reconnaissance range, and angle relationship of each direction finding and positioning station to form a series of processing methods such as angle thresholds and time sequence arrangement, which greatly improves the time difference positioning capability. Compared with traditional pure time difference extraction systems or single-station direction finding defuzzification systems, after multi-dimensional filtering processing, the computational load is reduced, and the positioning efficiency and accuracy are improved.

Description

Technical Field

[0001] This invention relates to the field of electronic signal reconnaissance and positioning technology, and more specifically, to a time difference extraction and filtering method, medium, and device based on multi-station direction finding. Background Technology

[0002] Passive positioning devices possess advantages such as high concealment, long operating range, and strong target recognition capabilities, making them an important means of acquiring target information. They mainly include cross-positioning and time-difference positioning (TDRP). Among these, TDRP technology is widely used in engineering applications due to its high positioning accuracy and simple algorithm. This technology utilizes the time difference in arrival times of signals from the same radiation source at multiple stations for positioning—a passive positioning method.

[0003] The traditional method first pairs the received pulse sequences to obtain the time difference Δt between the master station and other stations. n ={Δt n1 , Δt n2 …Δt nm The effective time difference value is obtained by histogram statistics of the time difference values, and then time difference positioning is calculated. In practical applications, the target distribution is dense and wide-ranging, and the signal environment is complex and heavily interleaved. If the calculation and positioning calculation are performed for every received signal pulse, the computational load is extremely large, and the probability of positioning ambiguity and flying points is high, which can directly lead to failure to locate in severe cases. At the same time, the positioning accuracy of time difference positioning is closely related to the baseline length. The longer the baseline, the higher the positioning accuracy. However, as the baseline is lengthened, the positioning ambiguity problem arises. The generation of ambiguity values ​​will cause the computational load for time difference extraction to increase by an order of magnitude, resulting in low positioning efficiency. Summary of the Invention

[0004] As users demand higher standards from reconnaissance equipment and its usage becomes more flexible, each positioning station now possesses single-system direction finding capabilities, cross-positioning capabilities when using dual systems in combination, and time-difference positioning and integrated positioning capabilities when using three or more systems in combination. In time-difference positioning, fully utilizing the existing direction finding information from each station helps improve positioning capabilities without increasing equipment costs. Therefore, this invention aims to provide a time-difference extraction and filtering method, medium, and device based on multi-station direction finding. This method utilizes the deployment coordinates, effective range, and direction finding angle relationships of each positioning station to generate angle thresholds, direction finding angle-reception time arrangement relationships, and maximum positioning angles. This improves time-difference pairing efficiency, reduces the probability of generating ambiguous time-difference values, and thus achieves the filtering effect for time-difference extraction.

[0005] This invention provides a time difference extraction and filtering method based on multi-station direction finding, comprising the following steps:

[0006] S1, calculate the generation angle threshold;

[0007] S2, Calculate and generate a direction finding angle-reception time arrangement mapping table;

[0008] S3, set the maximum positioning angle;

[0009] S4, calculate the fuzzy time difference window;

[0010] S5, the generated angle threshold, direction finding angle-reception time arrangement mapping table, maximum positioning angle, and fuzzy time difference window are used for time difference extraction and filtering.

[0011] Furthermore, in step S1, the method for calculating the generation angle threshold includes:

[0012] Based on the deployment of each positioning station, angle thresholds are calculated and generated using triangulation.

[0013] Furthermore, the angle threshold for a typical scenario where the three positioning stations are deployed in a straight line is:

[0014]

[0015] Equation (1) is used to calculate the bilateral time difference angle relationship between the left and right substations. α2 and α3 are the bilateral time difference angle thresholds, R2 and R3 are the effective distances of the substations, d1 and d2 are the baseline distances, and θ2 and θ3 are the angles between the airspace range and the baseline. Similarly, the unilateral time difference angle ranges β2 and β3 can be calculated using trigonometric relationships. Then, the angle ranges α1 and β1 of the main station are calculated according to the application requirements. Thus, the bilateral time difference angle thresholds are {α1, α2, α3}, and the unilateral time difference angle thresholds are {β1, β2, β3}.

[0016] Furthermore, in step S2, the method for calculating and generating the direction-finding angle-reception time arrangement mapping table includes:

[0017] The angular range of the left and right areas is determined by the pointing relationship of the intermediate positioning station, and a direction finding angle-reception time arrangement mapping table is generated based on the direction finding angle relationship of each positioning station.

[0018] Furthermore, the following logical relationship is generated by traversing each region as a direction-finding angle-reception time sorting mapping table:

[0019]

[0020] Where, θ i This indicates the orientation angle of a specific positioning station. Illustrative angle relationship, t i The spaces between them indicate the order of the detection time.

[0021] Furthermore, in step S3, the method for setting the maximum positioning angle includes:

[0022] The maximum positioning angle near the baseline is set according to the deployment relationship of each station and the distribution of positioning errors; the principle for setting the maximum positioning angle includes at least the range where positioning is impossible and the range where positioning is incorrect.

[0023] Furthermore, in step S4, the method for calculating the fuzzy time difference window includes:

[0024]

[0025] Where ΔTOA is the time difference ambiguity value, corresponding to the PRI value of the received signal, d1, d2, ..., d n Let c be the baseline length between each positioning station and c be the speed of light.

[0026] Furthermore, in step S5, the method of using the generated angle threshold, direction finding angle-reception time arrangement mapping table, maximum positioning angle, and fuzzy time difference window for time difference extraction and filtering includes:

[0027] During normal operation, each positioning station receives data;

[0028] The data processing center groups the data received by each positioning station according to the detection time, detection frequency band, frequency, and repetition frequency;

[0029] Each group of data is filtered by angle threshold and maximum positioning angle to complete the selection of effective data.

[0030] Time difference matching and extraction are accomplished using a direction finding angle-reception time arrangement mapping table and a fuzzy time difference window.

[0031] The processed time difference pairing information is used to calculate time difference positioning, and point traces and flight tracks are generated based on the time difference data.

[0032] The present invention also provides a computer terminal storage medium storing computer terminal executable instructions, which are used to execute the above-described time difference extraction and filtering method based on multi-station direction finding.

[0033] The present invention also provides a computing device, comprising:

[0034] At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the above-described time difference extraction filtering method based on multi-station direction finding.

[0035] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0036] This invention fully utilizes the deployment coordinates, reconnaissance range, and angular relationships of each direction-finding and positioning station to form a series of processing methods, including angle thresholds and time sequence arrangements, which greatly improves time-difference positioning capabilities. Compared to traditional pure time-difference extraction systems or single-station direction-finding defuzzification systems, this invention reduces computational load and improves positioning efficiency and accuracy after multi-dimensional filtering. This method is not limited to the combination of one or more methods; all methods have a positive gain effect on time-difference positioning. Therefore, the method proposed in this invention has high application prospects in the field of passive positioning. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a flowchart of the time difference extraction and filtering method based on multi-station direction finding in an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the angle threshold relationship in an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the direction finding corresponding to the target area in an embodiment of the present invention.

[0041] Figure 4 This is a schematic diagram illustrating the extraction of time difference based on the detection time sequence in an embodiment of the present invention.

[0042] Figure 5 This is a schematic diagram of the maximum positioning angle in an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0045] Example

[0046] like Figure 1 As shown, this embodiment proposes a time difference extraction filtering method based on multi-station direction finding, including the following steps:

[0047] S1, calculate the generation angle threshold;

[0048] Time difference positioning requires at least three positioning stations to simultaneously detect target signals. Therefore, angle thresholds can be calculated using triangulation based on the deployment of each station. Each positioning station has corresponding technical parameters, such as operating range R, airspace coverage δ, and servo azimuth Φ. During operation, the common viewing angle range for bilateral and unilateral time differences is calculated based on the reconnaissance range relationship. The angle threshold is typically set when the three positioning stations are deployed in a straight line:

[0049]

[0050] Equation (1) calculates the bilateral time difference angle relationship between the left and right substations, where α2 and α3 are the bilateral time difference angle thresholds, R2 and R3 are the effective distances of the substations, d1 and d2 are the baseline distances, and θ2 and θ3 are the angles between the airspace range and the baseline. Similarly, the unilateral time difference angle ranges β2 and β3 can be calculated using trigonometric relationships. Then, the angle ranges α1 and β1 of the main station are calculated according to application requirements. Thus, the bilateral time difference angle thresholds are {α1, α2, α3}, and the unilateral time difference angle thresholds are {β1, β2, β3}. For other deployment scenarios, angles can be calculated based on trigonometric relationships.

[0051] It should be noted that, due to numerous factors affecting signal reception by positioning equipment, such as direction-finding accuracy, design margin, weather conditions, and target signal transmission power, the common field of view is generally larger than the design value. Therefore, an appropriate margin must be considered when generating the angle threshold. To address these factors, the angle threshold can be dynamically calculated using real-time information. During dynamic calculation, the main considerations are changes in the effective range, the expansion of the airspace coverage, and the dynamic adjustment of the servo angle.

[0052] S2, Calculate and generate a direction finding angle-reception time arrangement mapping table;

[0053] Once the coordinates of each positioning station are determined, under the same coordinate system, the direction-finding angles of each station in different airspaces will inevitably be different, and these angles will not change abruptly. By utilizing the sequence of detection times of each positioning station for targets in different airspaces, a direction-finding angle-detection time mapping table is formed. For example... Figure 3 As shown, during operation, the angular range of the left and right areas is determined by the pointing relationship of the intermediate positioning stations (divided separately when there are multiple intermediate stations). A direction-finding angle-reception time mapping table is generated based on the direction-finding angle relationship of each positioning station. Therefore, the following logical relationship is generated as the direction-finding angle-reception time mapping table by traversing each area:

[0054]

[0055] Where, θ i This indicates the orientation angle of a specific positioning station. Illustrative angle relationship, t i The spaces between them indicate the order of the detection time.

[0056] When extracting time differences, the receiving time is arranged according to the direction finding angles of each positioning station by consulting a mapping table. Pulse time differences are then extracted sequentially, effectively eliminating some ambiguous values ​​and improving the accuracy of time difference extraction. It should be noted that because there are certain errors in the direction finding angles of each positioning station, a certain margin should be considered when arranging the time sequence for critical areas of the area division.

[0057] S3, set the maximum positioning angle;

[0058] For time-difference positioning, the coordinates of the three positioning stations are (x1, y1), (x2, y2), and (x3, y3), respectively. The angles between the target and the two auxiliary stations are α and β, respectively. The detection times are t1, t2, and t3. The positioning equation is:

[0059]

[0060] Assume that time measurement and reconnaissance station location measurement are independent of each other, and that:

[0061]

[0062]

[0063] The variance of the positional error for target localization is:

[0064]

[0065] The root mean square error of the location is then:

[0066]

[0067] As can be seen from equation (5), the positioning error of the target is related to the angle between the target and each sub-station and the main station. That is, when the target is located on the baseline of the two reconnaissance stations, the positioning error is infinite.

[0068] Therefore, based on the deployment relationship of each station and the distribution of positioning errors, the maximum positioning angle near the baseline is set, such as... Figure 3 As shown. The principle for setting the maximum positioning angle is to include at least the unpositionable range and the erroneous positioning range. For areas with large errors near the baseline, the setting can be adjusted according to specific usage requirements.

[0069] S4, calculate the fuzzy time difference window;

[0070] Using the baseline lengths d1, d2, ..., d between each positioning station n The range of fuzzy PRI is calculated, and the pairing time difference with fuzziness is defuzzified.

[0071]

[0072] Where ΔTOA is the time difference ambiguity value, corresponding to the PRI value of the received signal, d1, d2, ..., d n Let c be the baseline length between each positioning station and c be the speed of light.

[0073] S5, the generated angle threshold, direction finding angle-reception time arrangement mapping table, maximum positioning angle, and fuzzy time difference window are used for time difference extraction and filtering.

[0074] After completing the calculations in steps S1 to S4, during normal operation, each positioning station receives data, and the data processing center groups the data received by each positioning station according to parameters such as reception time, reception frequency band, frequency, and repetition frequency. Each group of data is filtered by angle threshold and maximum positioning angle to complete the effective data screening. Then, time difference pairing and extraction are completed by using the direction finding angle-reception time arrangement mapping table and fuzzy time difference window. The processed time difference pairing information is used for time difference positioning calculation, and point traces and tracks are generated based on the time difference data.

[0075] Example:

[0076] The invention is illustrated using a typical three-station time difference system. For simplification, the three stations are deployed in a straight line at 180°, with a distance of 30km between them. The baseline normal direction is due north, and the instantaneous reconnaissance airspace of each station is 90 degrees.

[0077] The time difference extraction and filtering method based on multi-station direction finding includes:

[0078] (1) As Figure 2 As shown, based on the current instantaneous detection capability and the location of the servo center, the bilateral time difference angle threshold and the unilateral time difference angle threshold corresponding to each positioning station are dynamically calculated. In special cases, the master station only has a bilateral time difference angle range.

[0079] (2) Figure 3 As shown, different working areas are divided, and a direction-finding angle-reception time mapping table is determined. θ0 and t0 are the direction-finding angle and reception time of the main station A, θ1 and t1 are the direction-finding angle and reception time of the secondary station B, and θ2 and t2 are the direction-finding angle and reception time of the secondary station C. The direction-finding angle error Δθ should be considered when determining the area. Figure 4 The reduction in time difference calculations shown is quite significant.

[0080]

[0081] (3) Figure 5 As shown, the maximum positioning angle δ is set according to the deployment relationship of each station and the distribution of positioning errors.

[0082] (4) Calculate the ambiguity value of the time difference between medium and high repetition frequency (PRI) based on the baseline length deployed between the positioning stations and the application, which is PRI<200us.

[0083] (5) Data is grouped according to parameters such as detection time, detection frequency band, frequency and repetition frequency. Each group of data is filtered by the direction finding angle threshold and the maximum positioning angle to complete the effective data screening.

[0084] (6) When extracting time difference, the calculation amount is reduced by arranging the mapping table according to the direction finding angle-reception time, and the time difference data is filtered according to the time difference window.

[0085] (7) Perform time difference positioning calculation on the processed time difference pairing information, and generate point traces and flight tracks based on the time difference data.

[0086] Furthermore, in some embodiments, a computer terminal storage medium is proposed, storing computer terminal executable instructions for performing the time difference extraction filtering method based on multi-station direction finding as described in the preceding embodiments. Examples of computer storage media include magnetic storage media (e.g., floppy disks, hard disks, etc.), optical recording media (e.g., CD-ROMs, DVDs, etc.), or memory such as memory cards, ROMs, or RAMs. The computer storage medium can also be distributed across a network-connected computer system, for example, as an application store.

[0087] Furthermore, in some embodiments, a computing device is proposed, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the time difference extraction filtering method based on multi-station direction finding as described in the preceding embodiments. Examples of computing devices include PCs, tablet computers, smartphones, or PDAs.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A time difference extraction and filtering method based on multi-station direction finding, characterized in that, Includes the following steps: S1, calculate the generation angle threshold; S2, Calculate and generate a direction finding angle-reception time arrangement mapping table; S3, set the maximum positioning angle; S4, calculate the fuzzy time difference window; S5, the generated angle threshold, the direction finding angle-reception time arrangement mapping table, the maximum positioning angle, and the fuzzy time difference window are used for time difference extraction and filtering: During normal operation, each positioning station receives data; The data processing center groups the data received by each positioning station according to the detection time, detection frequency band, frequency, and repetition frequency; Each group of data is filtered by angle threshold and maximum positioning angle to complete the selection of effective data. Time difference matching and extraction are accomplished using a direction finding angle-reception time arrangement mapping table and a fuzzy time difference window. The processed time difference pairing information is used to calculate time difference positioning, and point traces and flight tracks are generated based on the time difference data.

2. The time difference extraction and filtering method based on multi-station direction finding according to claim 1, characterized in that, In step S1, the method for calculating the generation angle threshold includes: Based on the deployment of each positioning station, angle thresholds are calculated and generated using triangulation.

3. The time difference extraction and filtering method based on multi-station direction finding according to claim 2, characterized in that, The angle threshold for a typical scenario where three positioning stations are deployed in a straight line is: Equation (1) is used to calculate the bilateral time difference angle relationship between the left and right auxiliary stations. , This is the bilateral time difference angle threshold. , For the distance of operation of the secondary station, d 1 、d 2 represents the baseline distance. , This represents the angle between the airspace range and the baseline; similarly, the range of the time difference angle on one side can be calculated using trigonometric relationships. , Then calculate the angle range of the main station based on application requirements. , Therefore, the bilateral time difference angle threshold is obtained as follows: The single-sided time difference angle threshold is .

4. The time difference extraction and filtering method based on multi-station direction finding according to claim 1, characterized in that, In step S2, the method for calculating and generating the direction-finding angle-reception time arrangement mapping table includes: The angular range of the left and right areas is determined by the pointing relationship of the intermediate positioning station, and a direction finding angle-reception time arrangement mapping table is generated based on the direction finding angle relationship of each positioning station.

5. The time difference extraction and filtering method based on multi-station direction finding according to claim 4, characterized in that, The following logical relationship is generated by traversing each region as a direction finding angle-reception time sorting mapping table: in, This indicates the orientation angle of a specific positioning station. Illustrative angle relationship formula, The spaces between them indicate the order of the detection time.

6. The time difference extraction and filtering method based on multi-station direction finding according to claim 1, characterized in that, In step S3, the method for setting the maximum positioning angle includes: The maximum positioning angle near the baseline is set according to the deployment relationship of each station and the distribution of positioning errors; the principle for setting the maximum positioning angle includes at least the range where positioning is impossible and the range where positioning is incorrect.

7. The time difference extraction and filtering method based on multi-station direction finding according to claim 1, characterized in that, In step S4, the method for calculating the fuzzy time difference window includes: in, This is the time difference ambiguity value, corresponding to the PRI value of the received signal. d 1. d 2、...、 d n The baseline length between each positioning station. c It is the speed of light.

8. A computer terminal storage medium storing computer terminal executable instructions, characterized in that, The computer terminal can execute instructions for performing the time difference extraction and filtering method based on multi-station direction finding as described in any one of claims 1-7.

9. A computing device, characterized in that, include: At least one processor; And a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the time difference extraction filtering method based on multi-station direction finding as described in any one of claims 1-7.

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