Time difference of arrival positioning ambiguity resolution method based on multi-station direction finding positioning, medium and device

Abstract

The application provides a time difference positioning ambiguity method based on multi-station direction finding positioning, a medium and a device, the method comprising: a central positioning station collecting original data sets of each auxiliary positioning station, and performing data grouping on the original data; according to the signal conditions of each positioning station, selecting a positioning station with a longer baseline for cross positioning; calculating the time difference based on the position of the cross positioning; estimating the time difference error according to the deployment conditions and direction finding accuracy of each positioning station; generating a time difference threshold based on the calculated time difference and the time difference error; after data grouping, the time difference positioning branch performs pulse-by-pulse time difference pairing; filtering the time difference pairing results according to the time difference threshold; and performing point track calculation and track association based on the filtered time difference pairing results. Through the application, the baseline of the time difference positioning can be further extended under the prerequisite of meeting the target common view requirement, which is conducive to improving the time difference positioning accuracy.

Description

Technical Field

[0001] This invention relates to the field of electronic signal reconnaissance and positioning technology, and more specifically, to a method, medium, and device for resolving time difference positioning ambiguity based on multi-station direction finding and positioning. 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-location 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. The positioning accuracy of TDRP is closely related to the baseline length; a longer baseline results in higher accuracy. However, as the baseline length increases, positioning ambiguity arises, especially when the radiation source signal is a high-repetition-rate signal, causing more severe ambiguity pairing problems and making accurate positioning difficult.

[0003] There is considerable research on time difference positioning ambiguity both domestically and internationally, including statistical deambiguity methods, deambiguity methods utilizing auxiliary information, and methods for handling special targets. Statistical deambiguity methods include: (1) eliminating positioning ambiguity based on the principle that the real target position cannot change abruptly in a short time while the position of false points changes abruptly; (2) eliminating positioning ambiguity using the histogram of pulse arrival time difference. Deambiguity methods utilizing auxiliary information mainly involve adding single-station auxiliary direction finding to distinguish the airspace where the target is located, and removing some false time difference pairs based on the different pulse arrival sequences in different airspaces to resolve positioning ambiguity. Methods for handling special targets mainly include methods for resolving time difference positioning ambiguity using pulse interval increments, removing time difference positioning ambiguity using Doppler information of moving targets, and deambiguity using the slight modulation of arrival time caused by radial offset due to target motion.

[0004] The above methods have solved the problem of time difference positioning ambiguity to some extent, but there is still room for improvement in de-positioning ambiguity for high repetition frequency signals or multi-target signal interleaving. For example, the computational load of high repetition frequency and multi-signal interleaving ambiguity decomposition is large, false positioning points without divergence characteristics cannot be well distinguished, the method of adding auxiliary direction finding to the main station only contains one-dimensional information and has weak de-ambiguity capability, and the de-ambiguity decomposition of moving characteristic targets requires high conditions and has insufficient wide application capability.

[0005] In summary, as the requirements for reconnaissance equipment become increasingly stringent and the methods of equipment use 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. When using multi-station time-difference positioning with this type of equipment, two types of problems exist:

[0006] First, when faced with high repetition rate signals, multiple targets, and complex electromagnetic environment signals, positioning ambiguity is inevitable.

[0007] Secondly, time difference positioning has high requirements for the common line of sight of the target signal. The baseline distance between positioning stations cannot be too long. When direction finding is used for direct positioning, the cross positioning error is much greater than that of time difference positioning. Direction finding cross positioning is not very meaningful. Summary of the Invention

[0008] The present invention aims to provide a method, medium and device for resolving time difference positioning ambiguity based on multi-station orientation positioning, so as to solve the problems of positioning ambiguity and lateral information in time difference positioning.

[0009] This invention provides a time-difference positioning ambiguity resolution method based on multi-station direction finding, comprising the following steps:

[0010] S10, after each positioning station is deployed according to the usage requirements, time difference positioning reconnaissance work is carried out. Through communication between positioning stations, the central positioning station collects the raw data of each auxiliary positioning station and groups the raw data with signal characteristic parameters.

[0011] S20, Generate time difference threshold:

[0012] S21. Based on the signal conditions of each positioning station, select the positioning station with the longer baseline for cross-positioning.

[0013] S22, calculate the time difference in reverse based on the cross-positioning location;

[0014] S23, Estimate the time difference error based on the deployment of each positioning station and the direction finding accuracy;

[0015] S24, generate a time difference threshold based on the inverse calculation of time difference and time difference error;

[0016] S30, after data grouping, the time difference positioning branch performs pulse-by-pulse time difference pairing;

[0017] S40, Filter the time difference pairing results according to the time difference threshold to eliminate fuzzy pairing time differences;

[0018] S50 calculates the point trace based on the filtered time difference pairing results, then associates the flight track, and the time difference positioning ends.

[0019] Further, step S21 includes:

[0020] T(x e ,y eP0(x0,y0) is the true location of the radiation source, P1(x1,y1) and P2(x2,y2) are auxiliary positioning stations. During signal reconnaissance, the central positioning station and the auxiliary positioning stations respectively measure the direction of the radiation source and obtain the target azimuth angles as θ0, θ1 and θ2 respectively. During time difference inversion, the auxiliary positioning stations P1 and P2 with longer baselines are selected for cross positioning.

[0021] If the X-axis is aligned with the baseline, then the slopes a1 and a2 of position line P1T are:

[0022]

[0023] Rearranging equation (1) yields the system of linear equations:

[0024]

[0025] In the formula, b1 = y1 - a1x1, b2 = y2 - a2x2;

[0026] Solving the system of linear equations yields:

[0027]

[0028] Therefore, based on the known coordinates (x1, y1) of auxiliary positioning station P1, the coordinates (x2, y2) of auxiliary positioning station P2, and the azimuth angles θ1 and θ2, the coordinates of the radiation source T are determined as follows:

[0029] Further, step S22 includes:

[0030] Based on the coordinates of radiation source T Calculate the arrival time of the radiation source signal at each positioning station:

[0031]

[0032] In the formula, dt0, dt1, and dt2 are the time delays of the radiation source reaching each positioning station, respectively, and c is the speed of light;

[0033] Calculate the time difference between each positioning station based on the time delay of each station:

[0034]

[0035] In the formula, Δdt 10 To account for the time difference between auxiliary positioning station P1 and central positioning station P0, Δdt 20 The time difference between auxiliary positioning station P2 and central positioning station P0.

[0036] Further, step S23 includes:

[0037] The standard errors of direction finding for auxiliary positioning stations P1 and P2 are σ1 and σ2, respectively, and the standard error of the radiation source location is σ. x and σ y The azimuth angles θ1 and θ2 measured by auxiliary positioning stations P1 and P2 are:

[0038]

[0039] Differentiating equation (6) and neglecting the position error of the positioning station, we have:

[0040]

[0041] in, The positional error of the radiation source is obtained as follows:

[0042]

[0043] Assume that the measurement errors between each positioning station are independent, and that σ1=σ2=σ θ ,have:

[0044]

[0045] The root mean square error of the location is then:

[0046]

[0047] Based on the root mean square error of the positioning and the coordinates of the radiation source T The time difference error range was determined through geometric calculation.

[0048] Furthermore, in step S24, the method for generating the time difference threshold based on the inversely calculated time difference and time difference error includes:

[0049] The Monte Carlo method is used to estimate the time difference threshold based on the inverse calculation of the time difference and the time difference error.

[0050] 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 positioning ambiguity resolution method based on multi-station direction finding.

[0051] The present invention also provides a computing device, comprising:

[0052] 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 positioning ambiguity resolution method based on multi-station orientation finding.

[0053] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0054] In time-difference positioning (TDRP) where each direction-finding station simultaneously possesses direction-finding information, this invention fully utilizes the time insensitivity of direction finding and cross-positioning to calculate the time difference, generate a time difference threshold, and then perform time difference filtering to achieve time difference ambiguity removal. Through theoretical calculations and simulation analysis, within the error ellipse range, the time difference threshold calculated from the cross-positioning results exhibits stable error and controllable range, meeting the high repetition rate deambiguity requirements for most targets. Furthermore, this invention allows for further extension of the baseline in TDRP, while still meeting the target common-view requirement, thus improving TDRP accuracy. Attached Figure Description

[0055] 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.

[0056] Figure 1 This is a flowchart of a time difference positioning ambiguity resolution method based on multi-station direction finding in an embodiment of the present invention.

[0057] Figure 2 This is a schematic diagram of direction finding and time difference positioning in an embodiment of the present invention.

[0058] Figure 3 This is a schematic diagram of high repetition rate pulse-by-pulse matching within a 10ms beat in an embodiment of the present invention.

[0059] Figure 4 This is a schematic diagram of the fixed target cross-positioning error ellipse in an embodiment of the present invention.

[0060] Figure 5 This is a distribution diagram of the actual time difference and the inverse time difference of a fixed target in an embodiment of the present invention.

[0061] Figure 6 This is a time difference error distribution diagram for fixed target back-calculation in an embodiment of the present invention.

[0062] Figure 7 This is a distribution diagram of the actual time difference and the inverse time difference of the maneuvering target in an embodiment of the present invention.

[0063] Figure 8 This is a diagram showing the time difference error distribution for back-calculation of maneuvering targets in an embodiment of the present invention. Detailed Implementation

[0064] 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.

[0065] 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.

[0066] Example

[0067] like Figure 1 As shown in the figure, this embodiment proposes a time-difference positioning ambiguity resolution method based on multi-station direction finding, which includes the following steps:

[0068] S10. After each positioning station is deployed according to the usage requirements, time difference positioning reconnaissance work is carried out. Through communication between positioning stations, the central positioning station collects the raw data of each auxiliary positioning station and groups the raw data with signal characteristics (RF, DOA, etc.) to reduce the amount of calculation.

[0069] S20, Generate time difference threshold:

[0070] S21. Based on the signal conditions of each positioning station, select the positioning station with the longer baseline for cross-positioning.

[0071] T(x e ,y e P0(x0,y0) is the true location of the radiation source, P1(x1,y1) and P2(x2,y2) are auxiliary positioning stations. During signal reconnaissance, the central positioning station and the auxiliary positioning stations respectively measure the direction of the radiation source and obtain the target azimuth angles as θ0, θ1 and θ2 respectively. During time difference inversion, the auxiliary positioning stations P1 and P2 with longer baselines are selected for cross positioning.

[0072] If the X-axis is aligned with the baseline, then the slopes a1 and a2 of position line P1T are:

[0073]

[0074] Rearranging equation (1) yields the system of linear equations:

[0075]

[0076] In the formula, b1 = y1 - a1x1, b2 = y2 - a2x2;

[0077] Solving the system of linear equations yields:

[0078]

[0079] Therefore, based on the known coordinates (x1, y1) of auxiliary positioning station P1, the coordinates (x2, y2) of auxiliary positioning station P2, and the azimuth angles θ1 and θ2, the coordinates of the radiation source T are determined as follows:

[0080] S22, calculate the time difference in reverse based on the cross-positioning location;

[0081] Based on the coordinates of radiation source T Calculate the arrival time of the radiation source signal at each positioning station:

[0082]

[0083] In the formula, dt0, dt1, and dt2 are the time delays of the radiation source reaching each positioning station, respectively, and c is the speed of light;

[0084] Calculate the time difference between each positioning station based on the time delay of each station:

[0085]

[0086] In the formula, Δdt 10 To account for the time difference between auxiliary positioning station P1 and central positioning station P0, Δdt 20 The time difference between auxiliary positioning station P2 and central positioning station P0.

[0087] S23, Estimate the time difference error based on the deployment of each positioning station and the direction finding accuracy;

[0088] During cross-location, the positioning accuracy will vary due to factors such as baseline length, direction-finding accuracy, and the relative position of the target. The standard errors of direction finding for auxiliary positioning stations P1 and P2 are σ1 and σ2, respectively, and the standard error of the radiation source position is σ. x and σ y The azimuth angles θ1 and θ2 measured by auxiliary positioning stations P1 and P2 are:

[0089]

[0090] Differentiating equation (6) and neglecting the position error of the positioning station, we have:

[0091]

[0092] in, The positional error of the radiation source is obtained as follows:

[0093]

[0094] Assume that the measurement errors between each positioning station are independent, and that σ1=σ2=σ θ ,have:

[0095]

[0096] The root mean square error of the location is then:

[0097]

[0098] Based on the root mean square error of the positioning and the coordinates of the radiation source T The time difference error range was determined through geometric calculation.

[0099] S24, generate a time difference threshold based on the inverse calculation of time difference and time difference error;

[0100] After the inverse calculation of time difference and the generation of time difference error range, a time difference threshold [dt] is formed. -n0 ,dt +n0 When generating the time difference threshold, it is crucial to consider that a particular cross-positioning result is highly likely to fall within the boundary of the error ellipse, especially at the endpoint of the minor axis. In such cases, the error range will be amplified, leading to a reduction in the deblurring effect. To address this issue, multiple position calculations combined with time difference positioning track filtering can be used to eliminate flypoints.

[0101] S30, after data grouping, the time difference positioning branch performs pulse-by-pulse time difference pairing; in particular, at high repetition rate, multiple paired time difference results will be obtained within one working cycle. If directly used for positioning calculation, a large number of fuzzy positioning points will be generated.

[0102] S40, Filter the time difference pairing results according to the time difference threshold to eliminate fuzzy pairing time differences;

[0103] S50 calculates the point trace based on the filtered time difference pairing results, then associates the flight track, and the time difference positioning ends.

[0104] Example:

[0105] like Figure 2 As shown, this invention is illustrated using a typical three-station time difference system. All three stations can perform direction finding and high-precision TOA extraction. For simplicity, the three stations are arranged in a 180° straight line, with the baseline normal direction being due north, and the distance between stations is 30 km. The direction finding accuracy of each station is 0.8 degrees. The target radiation source signal repetition frequency is 27 μs, the baseline distance is 30 km, and the pulse arrangement within one 10 ms beat is as follows... Figure 3 As shown.

[0106] It should be understood that the accompanying drawings and simulation conditions described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0107] The time difference positioning ambiguity resolution method based on multi-station orientation finding includes the following steps:

[0108] (1) As Figure 2 As shown, each positioning station has direction finding and high-precision TOA extraction functions. After the positioning stations are deployed, when reconnoitering the target, the central positioning station, according to the mission requirements, coordinates with each auxiliary positioning station to initiate reconnaissance of the target radiation source. The raw data independently collected by each positioning station is collected to the central positioning station through inter-station communication.

[0109] (2) The central positioning station pre-groups the collected raw data according to the frequency, time and direction information, and sends them to the pulse pairing extraction time difference branch and the cross positioning extraction time difference gate line branch for calculation.

[0110] (3) Based on the information received by each positioning station, P1 and P2 stations with longer baselines are selected for cross-positioning and error estimation. The following considers the cases of fixed targets and high-speed moving targets respectively:

[0111] Assuming the target is stationary, the coordinates of the target radiation source are (-30km, 200km). The actual location of the target radiation source and the distribution of the positioning ellipse are as follows: Figure 4 As shown, the time difference is calculated according to equations (3) to (5) as follows: Figure 5 As shown, the inverse time difference error distribution is as follows: Figure 6 As shown. Through simulation calculations, the time difference thresholds for the left station are [18us, 26us], and the time difference thresholds for the right station are [-3us, -12us].

[0112] Assuming the target is a moving target, with its radiation source located between (-50km, 100km) and (-100km, 300km) at a speed of 500km / h, the time difference situation is compared as follows: Figure 7 As shown (time difference comparison at each point), the inverse time difference error range is as follows: Figure 8 As shown. Simulation calculations show that the time difference threshold for the left station is [Δdt]. 10 +8us,Δdt 10 -8us], the right station time difference threshold is [Δdt] 20 +8us,Δdt 20 -8us].

[0113] The time difference threshold is calculated using the above steps and then fed into the time difference filter.

[0114] (4) After data pre-grouping, the time difference positioning branch performs pulse-by-pulse pairing. For simplicity, only the fixed target pairing situation in step (3) is shown here, as shown in equation (11). There is a large amount of ambiguous time difference, and according to the left station time difference threshold [dt] -n0 ,dt +n0 The time difference threshold between the right station and the right station is [dt]. -n0 ,dt +n0 The time difference after filtering is shown in equation (12).

[0115]

[0116]

[0117] In particular, as can be seen from the above calculation process, the filtering effect on high repetition rate signals is still very ideal.

[0118] (5) Based on the filtered time difference pairing results, the point track is calculated, and then the track is associated, and the time difference positioning ends.

[0119] Furthermore, in some embodiments, a computer terminal storage medium is proposed, storing computer terminal executable instructions for executing the time difference localization ambiguity resolution 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.

[0120] 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 positioning ambiguity resolution method based on multi-station direction-finding positioning as described in the foregoing embodiments. Examples of computing devices include PCs, tablets, smartphones, or PDAs.

[0121] 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-of-arrival positioning ambiguity resolution method based on multi-station direction finding positioning, characterized in that, Includes the following steps: S10, after each positioning station is deployed according to the usage requirements, time difference positioning reconnaissance work is carried out. Through communication between positioning stations, the central positioning station collects the raw data of each auxiliary positioning station and groups the raw data with signal characteristic parameters. S20, Generate time difference threshold: S21. Based on the signal conditions of each positioning station, select the positioning station with the longer baseline for cross-positioning. S22, calculate the time difference in reverse based on the cross-positioning location; S23, Estimate the time difference error based on the deployment of each positioning station and the direction finding accuracy; S24, generate a time difference threshold based on the inverse calculation of time difference and time difference error; S30, after data grouping, the time difference positioning branch performs pulse-by-pulse time difference pairing; S40, Filter the time difference pairing results according to the time difference threshold to eliminate fuzzy pairing time differences; S50 calculates the point trace based on the filtered time difference pairing results, then associates the track, and the time difference positioning ends; Step S21 includes: T( x e , y e P0 is the actual location of the radiation source. x 0, y 0) is the central positioning station, P1( x 1, y 1) and P2 x 2, y 2) As auxiliary positioning stations, during signal reconnaissance, the central positioning station and auxiliary positioning stations respectively measure the direction of the radiation source and obtain the target azimuth angles as θ0, θ1 and θ2 respectively; during time difference inversion, auxiliary positioning stations P1 and P2 with longer baselines are selected for cross positioning. If we align the X-axis with the baseline, then the slope of the position line P1T is... a 1 and the slope of position line P2T a 2, respectively: （1） Rearranging equation (1) yields the system of linear equations: （2） In the formula, ; Solving the system of linear equations yields: （3） Therefore, based on the known coordinates of the auxiliary positioning station P1 ( x 1, y 1) Coordinates of auxiliary positioning station P2 ( x 2, y 2) and azimuth angle θ 1 and θ 2. Determine the coordinates of the radiation source T as follows: ; Step S22 includes: Based on the coordinates of radiation source T Calculate the arrival time of the radiation source signal at each positioning station: （4） In the formula, , , denoted by , where represents the time delay for the radiation source to reach each positioning station, and c represents the speed of light; Calculate the time difference between each positioning station based on the time delay of each station: （5） In the formula, To assist in understanding the time difference between positioning station P1 and central positioning station P0, To assist in the time difference between positioning station P2 and central positioning station P0; Step S23 includes: The standard error of direction finding for auxiliary positioning stations P1 and P2 is: σ 1 and σ 2. The standard error of the radiation source location is σ x and σ y ; Azimuth angles measured by auxiliary positioning stations P1 and P2 θ 1 and θ 2 is: （6） Taking the differential of equation (6), neglecting the position error of the positioning station, we have: （7） in, The position error of the radiation source is obtained as follows: （8） Make the measurement errors between each positioning station independent, and σ 1= σ 2= σ θ ,have: （9） The root mean square error of the location is then: （10） Based on the root mean square error of the positioning and the coordinates of the radiation source T The time difference error range was determined through geometric calculation.

2. The time-difference positioning ambiguity resolution method based on multi-station direction finding and positioning according to claim 1, characterized in that, In step S24, the method for generating the time difference threshold based on the inversely calculated time difference and time difference error includes: The Monte Carlo method is used to estimate the time difference threshold based on the inverse calculation of the time difference and the time difference error.

3. A computer terminal storage medium storing computer terminal executable instructions, characterized in that, The computer terminal can execute instructions for performing the time difference positioning ambiguity resolution method based on multi-station direction finding as described in any one of claims 1-2.

4. 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 positioning ambiguity resolution method based on multi-station direction finding as described in any one of claims 1-2.

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