TDOA and AOA fusion positioning method and system

Abstract

Provided in the present invention are a TDOA and AOA fusion positioning method and system. The method comprises: TDOA stations respectively receiving signals within measurement ranges thereof, and if a target signal is received, forming first target data, wherein the first target data comprises information of the time when the target signal is received; on the basis of the first target data formed by N TDOA stations, obtaining estimated two-dimensional coordinates; on the basis of the estimated two-dimensional coordinates, using an AOA station to perform AOA measurement processing, so as to obtain an estimated height between the AOA station and a target, wherein the estimated height serves as an initial calibration height; on the basis of the estimated two-dimensional coordinates, obtaining estimated distances between the N TDOA stations and the target; on the basis of the estimated distances and the initial calibration height, iteratively updating the estimated distance between the N TDOA stations and the target, so as to obtain target two-dimensional coordinates and a target height; and fusing the target two-dimensional coordinates and the target height, so as to obtain target three-dimensional coordinates. The present invention achieves relatively accurate two-dimensional positioning and target heights, thereby realizing highly accurate three-dimensional positioning.

Description

TDOA and AOA Fusion Localization Method and System Technical Field

[0001] This invention relates to the field of signal positioning technology, and in particular to a TDOA and AOA fusion positioning method and system. Background Technology

[0002] TDOA technology can locate the transmitter source position by the time difference of the target signal reaching multiple TDOA stations.

[0003] However, TDOA technology faces challenges in three-dimensional (3D) positioning, as its positioning accuracy is strictly limited by the deployment environment (location and altitude) of TDOA sites. Specifically, in practical applications, it is difficult to space TDOA sites far enough apart in the height dimension, resulting in a large height error in the 3D positioning results, which also affects the position accuracy. Therefore, in most cases, only two-dimensional (2D) positioning can be achieved.

[0004] However, the accuracy of this 2D positioning algorithm is relatively low because it ignores the impact of altitude information on time difference, resulting in inaccurate positioning. For example, if there is an aerial target at the same location, the time difference matrix of the target signal obtained by the receiver will change with altitude, causing deviations in the 2D positioning calculation results. In complex environments, this error will be more pronounced.

[0005] Therefore, how to use TDOA technology to achieve high-precision three-dimensional positioning technology has become a technical problem that urgently needs to be solved in the industry. Summary of the Invention

[0006] This invention provides a TDOA and AOA fusion positioning method and system, which solves the problem that it is difficult to achieve high-precision three-dimensional positioning technology using TDOA technology.

[0007] According to a first aspect of the present invention, a TDOA and AOA fusion positioning method is provided, wherein the number of TDOA sites is N, where N is an integer greater than or equal to 3, and the method includes:

[0008] Each TDOA station receives signals within its measurement range. If a target signal is received, first target data is generated, which includes the time information of the time the target signal was received.

[0009] Based on the first target data formed by the N TDOA sites, the estimated two-dimensional coordinates are obtained;

[0010] Based on the estimated two-dimensional coordinates, AOA measurement processing is performed using the AOA station to obtain the estimated height between the AOA station and the target, and the estimated height is used as the initial calibration height.

[0011] Based on the estimated two-dimensional coordinates, the estimated distances between the N TDOA stations and the target are obtained;

[0012] Based on the estimated distance and the initial calibration height, the estimated distances between the N TDOA stations and the target are iteratively updated to obtain the target's two-dimensional coordinates and target height;

[0013] The target's two-dimensional coordinates and target height are fused to obtain the target's three-dimensional coordinates.

[0014] Optionally, the step of obtaining the estimated two-dimensional coordinates based on the first target data formed by the N TDOA sites includes:

[0015] Calculate the time difference between the TDOA stations based on the time information in the first target data: τ ij =t i -t j

[0016] Where, τ ij t represents the time difference between the i-th (i = 1, 2, ..., N) TDOA station and the j-th (j = 1, 2, ..., N) TDOA station receiving the target signal. i t represents the time at which the i-th TDOA station receives the target signal. j This indicates the time when the j-th TDOA station receives the target signal;

[0017] Obtain the time difference matrix based on the stated time difference:

[0018] Wherein, △T0 represents the time difference matrix;

[0019] The estimated two-dimensional coordinates are obtained based on the time difference matrix.

[0020] Optionally, the step of obtaining the estimated height by performing AOA measurement processing using the estimated two-dimensional coordinates and AOA sites includes:

[0021] The AOA station receives signals within its measurement range. If the target signal is received, second target data is generated, which includes the directional intensity of the target signal.

[0022] Identify the direction of the maximum signal strength of the target signal, and obtain the target estimated pitch angle from the AOA station to the target based on the location of the AOA station and the direction of the maximum signal strength of the target signal;

[0023] The estimated altitude is obtained based on the estimated pitch angle of the target and the estimated two-dimensional coordinates.

[0024] Optionally, the step of iteratively updating the estimated distances between the N TDOA stations and the target to obtain the target's two-dimensional coordinates and height includes:

[0025] Based on the estimated distance and the initial calibration altitude, update the estimated distances between N TDOA stations and the target;

[0026] Based on the updated estimated distance, the time difference between the N TDOA stations is updated to obtain the updated time difference matrix;

[0027] Based on the updated time difference matrix, the estimated two-dimensional coordinates are updated to obtain the updated estimated two-dimensional coordinates;

[0028] Determine whether the difference between the estimated two-dimensional coordinates and the updated estimated two-dimensional coordinates is less than a first preset distance;

[0029] If not, based on the updated estimated 2D coordinates, perform AOA measurement processing using the AOA site, update the estimated height, update the initial calibration height based on the updated estimated height and the estimated height, and continue iteratively updating based on the updated estimated distance and the updated initial calibration height;

[0030] If so, the updated estimated two-dimensional coordinates are determined to be the target two-dimensional coordinates. Based on the updated estimated two-dimensional coordinates, the estimated height is updated using AOA measurement processing at the AOA site. The initial calibration height is updated according to the updated estimated height and the estimated height. The updated initial calibration height is used as the target height.

[0031] Optionally, the initial calibration height is updated based on the estimated height and the updated estimated height:

[0032] H′ n =|H n -H n-1 |

[0033] Where n is a positive integer, n represents the number of iterations, and H n ′ represents the initial calibration height after the nth update, H n H0 represents the estimated height after the nth update.

[0034] Optionally, based on the estimated distance or the updated estimated distance and the initial calibration altitude, update the estimated distances between the N TDOA stations and the target:

[0035] Where, d n,i d represents the estimated distance between the i-th TDOA site and the target after the n-th update. 0,i H0′ represents the estimated distance between the i-th TDOA station and the target, and H0′ represents the initial calibration height, which is equal to the estimated height.

[0036] Optionally, based on the updated estimated distance, update the time difference between the N TDOA sites:

[0037] Among them, T n,ij d represents the time difference after the nth update between the i-th (i = 1, 2, ..., N) TDOA site and the j-th (j = 1, 2, ..., N) TDOA site. n,i d represents the estimated distance between the i-th TDOA site and the target after the n-th update. n,i This represents the estimated distance between the i-th TDOA site and the target after the n-th update, where c is the speed of light, and c ≈ 3 × 10⁻⁶. 8 km / h.

[0038] Optionally, based on the updated time differences between the N TDOA sites, an updated time difference matrix is ​​obtained:

[0039] Among them, △T n Let represent the time difference matrix after the nth update.

[0040] Optionally, the first set distance is 3m.

[0041] Optionally, the distance between any two TDOA sites is greater than or equal to 300m.

[0042] Optionally, the AOA sites are distributed within the area where the TDOA sites are distributed.

[0043] Optionally, the two-dimensional coordinates of the target and the target height are fused to obtain the three-dimensional coordinates of the target:

[0044] Among them, P 3d P represents the three-dimensional coordinates of the target. 2d H represents the two-dimensional coordinates of the target, and H′ represents the height of the target. This symbol represents the fusion of physics.

[0045] According to a second aspect of the present invention, a TDOA and AOA fusion positioning system is provided, wherein the number of TDOA stations in the system is N, where N is an integer greater than or equal to 3, and the system includes:

[0046] Target recognition module: Each TDOA station receives signals within its measurement range. If a target signal is received, first target data is generated, which includes the time information of receiving the target signal.

[0047] Two-dimensional coordinate acquisition module: Based on the first target data formed by N TDOA sites, obtain estimated two-dimensional coordinates;

[0048] Estimated height acquisition module: Based on the estimated two-dimensional coordinates, AOA measurement processing is performed using the AOA site to obtain the estimated height, which is used as the initial calibration height;

[0049] Distance estimation module: Based on the estimated two-dimensional coordinates, obtain the estimated distances between the N TDOA stations and the target;

[0050] Iterative calibration module: Based on the estimated distance and the initial calibration height, iteratively updates the estimated distances between the N TDOA stations and the target to obtain the target's two-dimensional coordinates and target height;

[0051] Coordinate transformation module: fuses the two-dimensional coordinates of the target and the target height to obtain the three-dimensional coordinates of the target.

[0052] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0053] This invention provides a positioning method that integrates Time Difference of Arrival (TDOA) and Angle of Arrival (AOA) measurement. Each TDOA station receives signals within its measurement range. If a target signal is received, first target data is generated, including the time information of the received target signal. Based on the first target data generated by N TDOA stations, estimated two-dimensional coordinates are obtained. Based on the estimated two-dimensional coordinates, AOA measurement processing is performed using AOA stations to obtain an estimated height. An initial calibration height is obtained from the estimated height. Based on the estimated two-dimensional coordinates, estimated distances between the N TDOA stations and the target are obtained. Based on the estimated distances and the initial calibration height, the estimated distances between the N TDOA stations and the target are iteratively updated to obtain the target's calibrated two-dimensional coordinates and target height. The target's two-dimensional coordinates and target height are fused to obtain the target's three-dimensional coordinates. This method not only improves the accuracy of two-dimensional positioning and obtains a more accurate target height but also achieves high-precision three-dimensional positioning. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 is a flowchart illustrating the TDOA and AOA fusion positioning method in an embodiment of the present invention;

[0056] Figure 2 is a schematic diagram of the TDOA site distribution in an embodiment of the present invention;

[0057] Figure 3 is a flowchart illustrating the TDOA and AOA fusion positioning method in the first embodiment of the present invention;

[0058] Figure 4 is a flowchart illustrating the TDOA and AOA fusion positioning method in the second embodiment of the present invention;

[0059] Figure 5 is a schematic diagram of the distribution of TDOA sites and AOA sites in an embodiment of the present invention;

[0060] Figure 6 is a flowchart illustrating the TDOA and AOA fusion positioning method in the third embodiment of the present invention;

[0061] Figure 7 is a schematic diagram of the TDOA and AOA fusion positioning system in an embodiment of the present invention;

[0062] Figure labeling: 71 - Target identification module; 72 - Two-dimensional coordinate acquisition module; 73 - Estimated height acquisition module; 74 - Distance estimation module; 75 - Iterative calibration module; 76 - Coordinate transformation module; X - Represents the horizontal axis; Y - Represents the vertical axis; Z - Represents the vertical coordinate axis; P - Represents the two-dimensional coordinate point of the target; H - Represents the vertical height of the target; d1 - Represents the distance between the 1st TDOA station and the target; d2 - Represents the distance between the 2nd TDOA station and the target; d3 - Represents the distance between the 3rd TDOA station and the target. Detailed Implementation

[0063] 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0064] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0065] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0066] As described in the background section, Time Difference of Origin (TDOA) positioning is a widely used positioning technology in wireless communication and radar systems. It locates the transmitting source by measuring the time difference of signals arriving at multiple receiving points. Its superior performance depends to some extent on the layout of the receiving sites—under ideal conditions where signal transmission is uninterrupted, reasonably and effectively increasing the distance between sites can significantly improve the accuracy and reliability of TDOA positioning. This is because a larger spacing between sites increases the discriminability of time differences, thus helping to more accurately calculate the target's coordinates. However, in practical applications, it is difficult to meet the strict limitations of the TDOA site deployment environment (location, altitude), which results in a large height error in the three-dimensional positioning results and also affects the positional accuracy. Therefore, in most cases, only two-dimensional positioning can be achieved, and even then, the accuracy is not high.

[0067] Given that achieving high-precision 3D positioning using TDOA technology has become a pressing technical problem in the industry, this invention provides a positioning method that fuses TDOA with AOA. Each TDOA station receives signals within its measurement range. If a target signal is received, first target data is generated, including the time information of the received target signal. Based on the first target data generated by N TDOA stations, estimated 2D coordinates are obtained. Based on the estimated 2D coordinates, AOA measurement processing is performed using AOA stations to obtain an estimated height, and an initial calibration height is obtained from the estimated height. Based on the estimated 2D coordinates, estimated distances between the N TDOA stations and the target are obtained. Based on the estimated distances and the initial calibration height, the estimated distances between the N TDOA stations and the target are iteratively updated to obtain the target calibration 2D coordinates and target height. The target 2D coordinates and target height are fused to obtain the target 3D coordinates. This method not only improves the accuracy of 2D positioning and obtains a high-precision target height but also achieves high-precision 3D positioning.

[0068] Please refer to Figure 1. This embodiment of the invention provides a TDOA and AOA fusion positioning method, wherein the number of TDOA sites is N, where N is an integer greater than or equal to 3, and the method includes:

[0069] S1: Each TDOA station receives signals within its measurement range. If a target signal is received, first target data is generated, which includes the time information of receiving the target signal.

[0070] S2: Based on the first target data formed by the N TDOA sites, obtain the estimated two-dimensional coordinates;

[0071] S3: Based on the estimated two-dimensional coordinates, perform AOA measurement processing using the AOA station to obtain the estimated height between the AOA station and the target, and use the estimated height as the initial calibration height;

[0072] S4: Based on the estimated two-dimensional coordinates, obtain the estimated distances between the N TDOA stations and the target;

[0073] S5: Based on the estimated distance and the initial calibration height, iteratively update the estimated distances between the N TDOA stations and the target to obtain the target's two-dimensional coordinates and target height;

[0074] S6: The target's two-dimensional coordinates and the target's height are fused to obtain the target's three-dimensional coordinates.

[0075] As can be seen, this invention provides a positioning method that integrates Time Difference of Arrival (TDOA) positioning and Angle of Arrival (AOA) measurement. Each TDOA station receives signals within its measurement range. If a target signal is received, first target data is generated, including the time information of the received target signal. Based on the first target data generated by N TDOA stations, estimated two-dimensional coordinates are obtained. Based on the estimated two-dimensional coordinates, AOA measurement processing is performed using AOA stations to obtain an estimated height. An initial calibration height is obtained from the estimated height. Based on the estimated two-dimensional coordinates, estimated distances between the N TDOA stations and the target are obtained. Based on the estimated distances and the initial calibration height, the estimated distances between the N TDOA stations and the target are iteratively updated to obtain the target calibration two-dimensional coordinates and the target height. The target two-dimensional coordinates and target height are fused to obtain the target three-dimensional coordinates. This method not only improves the accuracy of two-dimensional positioning and obtains a more accurate target height, but also achieves high-precision three-dimensional positioning.

[0076] In actual implementation, the placement of the stations can be referenced as shown in Figure 2. In one specific implementation, the distance between any two TDOA stations is greater than or equal to 300m.

[0077] Please refer to Figure 3 and proceed to step S2;

[0078] S2: Based on the first target data formed by the N TDOA sites, obtain the estimated two-dimensional coordinates.

[0079] In one implementation, step S2 includes the following steps:

[0080] S21: Calculate the time difference between the TDOA stations based on the time information in the first target data: τ ij =t i -t j

[0081] Where, τ ij t represents the time difference between the i-th (i = 1, 2, ..., N) TDOA station and the j-th (j = 1, 2, ..., N) TDOA station receiving the target signal. i t represents the time at which the i-th TDOA station receives the target signal. j This indicates the time when the j-th TDOA station receives the target signal; i and j can be equal;

[0082] S22: Obtain the time difference matrix based on the stated time difference:

[0083] Wherein, △T0 represents the time difference matrix;

[0084] S23: Obtain the estimated two-dimensional coordinates based on the time difference matrix;

[0085] In one specific implementation, the estimated two-dimensional coordinates are: P0 = TDOA(ΔT0)

[0086] Wherein, P0 represents the estimated two-dimensional coordinates, △T0 represents the estimated time difference matrix, and TDOA() is a time difference positioning algorithm, which is existing technology and will not be described in detail here.

[0087] Please refer to Figure 4 and proceed to step S3;

[0088] S3: Based on the estimated two-dimensional coordinates, perform AOA measurement processing using the AOA station to obtain the estimated height between the AOA station and the target, and use the estimated height as the initial calibration height.

[0089] In one embodiment, step S3, based on the estimated two-dimensional coordinates, performs AOA measurement processing using an AOA station to obtain the estimated height between the AOA station and the target, including the following steps:

[0090] S31: The AOA station receives signals within its measurement range. If the target signal is received, second target data is generated, which includes the directional intensity of the target signal.

[0091] S32: Identify the direction of the maximum signal strength of the target signal, and obtain the target estimated pitch angle from the AOA station to the target based on the location of the AOA station and the direction of the maximum signal strength of the target signal;

[0092] S33: The estimated height H0 is obtained based on the estimated pitch angle of the target and the estimated two-dimensional coordinates P.

[0093] In one specific implementation, the estimated height is: H0 = AOA(P0)

[0094] Wherein, H0 represents the estimated height, P0 represents the estimated two-dimensional coordinates, and AOA() is the arrival angle measurement and calculation algorithm, which is existing technology and will not be described in detail here.

[0095] In one embodiment, referring to Figure 5, the AOA sites of this embodiment are distributed within the area where the TDOA sites are distributed. In the example of Figure 5, the number of AOA sites is one. Of course, this invention is not limited to this, and the number of AOA sites can also be multiple. Using multiple AOA sites to obtain the estimated height between the AOA sites and the target is prior art and will not be elaborated here.

[0096] In one implementation, referring to Figure 6, the specific steps of the iterative update in step S5 include:

[0097] S401: Based on the estimated distance and the initial calibration altitude, update the estimated distances between the N TDOA stations and the target;

[0098] S402: Based on the updated estimated distance, update the time difference between the N TDOA stations to obtain the updated time difference matrix;

[0099] S403: Based on the updated time difference matrix, update the estimated two-dimensional coordinates P to obtain the updated estimated two-dimensional coordinates;

[0100] S404: Determine whether the difference between the estimated two-dimensional coordinates and the updated estimated two-dimensional coordinates is less than a first set distance. If not, proceed to S405; if yes, proceed to S406.

[0101] S405: Based on the updated estimated two-dimensional coordinates, perform AOA measurement processing using the AOA site, update the estimated height, update the initial calibration height according to the updated estimated height and the estimated height, and use the updated estimated distance and the updated initial calibration height as the new estimated distance and the new initial calibration height, then return to S401;

[0102] S406: Use the updated estimated two-dimensional coordinates as the target two-dimensional coordinates, perform AOA measurement processing using the AOA site based on the updated estimated two-dimensional coordinates, update the estimated height, update the initial calibration height according to the updated estimated height and the estimated height, and use the updated initial calibration height as the target height.

[0103] In one specific embodiment, the first set distance is 3m. Of course, the present invention is not limited to this, and those skilled in the art can choose a suitable set distance as needed.

[0104] In a specific implementation, in step S406, the initial calibration height and the updated initial calibration height are updated based on the estimated height and the updated estimated height: H′ n =|H n -H n-1 |

[0105] Where n is a positive integer, n represents the number of iterations, and H n ′ represents the initial calibration height after the nth update, H n H represents the estimated height after the nth update, and H0 represents the initial calibration height.

[0106] In a specific implementation, after updating the estimated distance or the updated estimated distance between the N TDOA stations and the target in step S401:

[0107] Where, d n,i d represents the estimated distance between the i-th TDOA site and the target after the n-th update. 0,i H0′ represents the estimated distance between the i-th TDOA station and the target, and H0′ represents the initial calibration height, which is equal to the estimated height.

[0108] In a specific implementation, the time difference between the N TDOA stations is updated based on the updated estimated distance:

[0109] Among them, T n,ij d represents the time difference after the nth update between the i-th (i = 1, 2, ..., N) TDOA site and the j-th (j = 1, 2, ..., N) TDOA site. n,i d represents the estimated distance between the i-th TDOA site and the target after the n-th update. n,i This represents the estimated distance between the i-th TDOA site and the target after the n-th update, where c is the speed of light, and c ≈ 3 × 10⁻⁶. 8 km / h.

[0110] In a specific implementation, an updated time difference matrix is ​​obtained based on the updated time differences between the N TDOA stations:

[0111] Among them, △T n Let represent the time difference matrix after the nth update.

[0112] In a specific implementation, the target's two-dimensional coordinates and the target's height are fused to obtain the target's three-dimensional coordinates:

[0113] Among them, P 3d P represents the three-dimensional coordinates of the target. 2d H represents the two-dimensional coordinates of the target, and H′ represents the height of the target. This symbol represents the fusion of physics.

[0114] The process of the first iteration update of this invention will now be described in detail based on the above formula:

[0115] The specific steps of the first iteration update include:

[0116] Based on the estimated distance and the initial calibration altitude, update the estimated distances between N TDOA stations and the target;

[0117] Specifically, based on the estimated distance and the initial calibration altitude, the estimated distances between the N TDOA stations and the target are updated:

[0118] Where, d 1,i d represents the estimated distance between the i-th TDOA site and the target after the first update. 0,i H0′ represents the estimated distance between the i-th TDOA station and the target, and H0′ represents the initial calibration altitude, where H0′=H0 and H0 represents the estimated altitude.

[0119] Based on the updated estimated distance, the time difference between the N TDOA stations is updated to obtain the updated time difference matrix;

[0120] Specifically, based on the updated estimated distance, the time difference between the N TDOA sites is updated:

[0121] Where, τ 1，ij d represents the time difference after the first update between the i-th (i = 1, 2, ..., N) TDOA site and the j-th (j = 1, 2, ..., N) TDOA site. 1,i d represents the estimated distance between the i-th TDOA site and the target after the first update. 1,j This represents the estimated distance between the j-th TDOA station and the target, where c is the speed of light, and c ≈ 3 × 10⁻⁶. 8 km / h.

[0122] Based on the updated time differences between the N TDOA stations, the updated time difference matrix is ​​obtained:

[0123] Wherein, △T1 represents the time difference matrix after the first update.

[0124] Based on the updated time difference matrix, the estimated two-dimensional coordinates are updated to obtain the updated estimated two-dimensional coordinates;

[0125] Specifically, the updated estimated two-dimensional coordinates P1 = TDOA(ΔT1)

[0126] Wherein, P1 represents the estimated two-dimensional coordinates after the first update, △T1 represents the estimated time difference matrix after the first update, and TDOA() is the time difference positioning solution algorithm, which is existing technology and will not be described in detail here.

[0127] Determine whether the difference between the estimated two-dimensional coordinates and the updated estimated two-dimensional coordinates is less than a first preset distance;

[0128] For example, the first set distance is 3m;

[0129] If not, then based on the updated estimated 2D coordinates, perform AOA measurement processing using the AOA site, update the estimated height, update the initial calibration height according to the updated estimated height and the estimated height, and use the updated estimated distance and the updated initial calibration height as the new estimated distance and the new initial calibration height, and continue iteratively updating;

[0130] Specifically, based on the updated estimated two-dimensional coordinates and using the AOA site for AOA measurement processing, the estimated height is updated, and the updated estimated height H1 = AOA(P1).

[0131] Wherein, H1 represents the estimated height after the first update, P1 represents the estimated two-dimensional coordinates after the first update, and AOA() represents the angle measurement and calculation algorithm, which is existing technology and will not be described in detail here.

[0132] Specifically, the initial calibration height is updated based on the updated estimated height and the estimated height: H′1=|H1-H0|

[0133] Where 1 indicates that the number of iterations is 1, H1′ indicates the initial calibration height after the first update, H1 indicates the estimated height after the first update, and H0 indicates the initial calibration height.

[0134] If so, determine that the updated estimated two-dimensional coordinates are the target two-dimensional coordinates, update the updated estimated height, update the initial calibration height based on the updated estimated height and the estimated height, and use the updated initial calibration height as the target height.

[0135] In summary, this invention provides a positioning method that integrates Time Difference of Arrival (TDOA) and Angle of Arrival (AOA) measurement. Each TDOA station receives signals within its measurement range. If a target signal is received, first target data is generated, including the time information of the received target signal. Based on the first target data generated by N TDOA stations, estimated two-dimensional coordinates are obtained. Based on the estimated two-dimensional coordinates, AOA measurement processing is performed using AOA stations to obtain an estimated height. An initial calibration height is obtained from the estimated height. Based on the estimated two-dimensional coordinates, estimated distances between the N TDOA stations and the target are obtained. Based on the estimated distances and the initial calibration height, the estimated distances between the N TDOA stations and the target are iteratively updated to obtain the target calibration two-dimensional coordinates and the target height. The target two-dimensional coordinates and target height are fused to obtain the target three-dimensional coordinates. This method not only improves the accuracy of two-dimensional positioning and obtains a more accurate target height, but also achieves high-precision three-dimensional positioning.

[0136] Furthermore, referring to Figure 7, this invention also provides a TDOA and AOA fusion positioning system, wherein the number of TDOA stations is N, where N is an integer greater than or equal to 3, and the system includes:

[0137] Target recognition module 71: Each TDOA station receives signals within its measurement range. If a target signal is received, first target data is generated, which includes the time information of receiving the target signal.

[0138] Two-dimensional coordinate acquisition module 72: Obtains estimated two-dimensional coordinates based on the first target data formed by N TDOA sites;

[0139] Estimated height acquisition module 73: Based on the estimated two-dimensional coordinates, AOA measurement processing is performed using the AOA site to obtain the estimated height, which is used as the initial calibration height;

[0140] Distance estimation module 74: Based on the estimated two-dimensional coordinates, obtain the estimated distances between the N TDOA stations and the target;

[0141] Iterative calibration module 75: Based on the estimated distance and the initial calibration height, iteratively updates the estimated distances between the N TDOA stations and the target to obtain the target's two-dimensional coordinates and target height;

[0142] Coordinate transformation module 76: fuses the two-dimensional coordinates of the target and the target height to obtain the three-dimensional coordinates of the target.

[0143] In one implementation, the AOA site is within the TDOA site range.

[0144] In summary, this invention provides a positioning method that integrates Time Difference of Arrival (TDOA) and Angle of Arrival (AOA) measurement. Each TDOA station receives signals within its measurement range. If a target signal is received, first target data is generated, including the time information of the received target signal. Based on the first target data generated by N TDOA stations, estimated two-dimensional coordinates are obtained. Based on the estimated two-dimensional coordinates, AOA measurement processing is performed using AOA stations to obtain an estimated height. An initial calibration height is obtained from the estimated height. Based on the estimated two-dimensional coordinates, estimated distances between the N TDOA stations and the target are obtained. Based on the estimated distances and the initial calibration height, the estimated distances between the N TDOA stations and the target are iteratively updated to obtain the target calibration two-dimensional coordinates and the target height. The target two-dimensional coordinates and target height are fused to obtain the target three-dimensional coordinates. This method not only improves the accuracy of two-dimensional positioning and obtains a more accurate target height, but also achieves high-precision three-dimensional positioning.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A TDOA and AOA fusion positioning method, characterized in that, The number of TDOA stations is N, where N is an integer greater than or equal to 3; The method comprises: Each TDOA station receives signals within its measurement range, and if a target signal is received, first target data is formed, the first target data comprising time information of the target signal received; An estimated two-dimensional coordinate is obtained according to the first target data formed by the N TDOA stations; An estimated height between the AOA station and the target is obtained through AOA measurement processing based on the estimated two-dimensional coordinate, and the estimated height is used as an initial calibration height; An estimated distance between the N TDOA stations and the target is obtained based on the estimated two-dimensional coordinate; The estimated distance between the N TDOA stations and the target is iteratively updated based on the estimated distance and the initial calibration height, and a target two-dimensional coordinate and a target height are obtained; The target two-dimensional coordinate and the target height are fused to obtain a target three-dimensional coordinate. 2.The TDOA and AOA fusion positioning method of claim 1, wherein, The step of obtaining an estimated two-dimensional coordinate according to the first target data formed by the N TDOA stations comprises: The time difference between the TDOA stations is calculated according to the time information in the first target data: τ ij = t i - t j wherein τ ij denotes the time difference between the reception of the target signal by the i-th (i = 1, 2,..., N) TDOA station and the j-th (j = 1, 2,..., N) TDOA station, t i denotes the time of reception of the target signal by the i-th TDOA station, t j denotes the time of reception of the target signal by the j-th TDOA station; According to the time difference, a time difference matrix is obtained: Where ΔT0 represents the time difference matrix; The estimated two-dimensional coordinate is obtained according to the time difference matrix. 3.The TDOA and AOA fusion positioning method of claim 1, wherein, The step of obtaining an estimated height by using an AOA station to perform AOA measurement processing based on the estimated two-dimensional coordinate comprises: The AOA station receives signals within its measurement range, and if a target signal is received, second target data is formed, the second target data comprising the direction and intensity of the target signal; The direction of the maximum signal intensity of the target signal is identified, and a target estimated pitch angle of the AOA station to the target is obtained based on the position of the AOA station and the direction of the maximum signal intensity of the target signal; The estimated height is obtained according to the target estimated pitch angle and the estimated two-dimensional coordinate. 4.The TDOA and AOA fusion positioning method of claim 1, wherein, The step of iteratively updating the estimated distance between the N TDOA stations and the target to obtain a target two-dimensional coordinate and a target height comprises: The estimated distance between the N TDOA stations and the target is updated based on the estimated distance and the initial calibration height; The time difference between the N TDOA stations is updated based on the updated estimated distance, and an updated time difference matrix is obtained; The estimated two-dimensional coordinate is updated based on the updated time difference matrix, and an updated estimated two-dimensional coordinate is obtained; It is determined whether the difference between the estimated two-dimensional coordinate and the updated estimated two-dimensional coordinate is less than a first set distance; If not, the estimated height is updated based on the updated estimated two-dimensional coordinate by using the AOA station to perform AOA measurement processing, the initial calibration height is updated according to the updated estimated height and the estimated height, and the iterative updating is continued based on the updated estimated distance and the updated initial calibration height. If yes, the updated estimated two-dimensional coordinate is determined as the target two-dimensional coordinate, the AOA station is used to update the estimated height based on the updated estimated two-dimensional coordinate, the initial calibration height is updated according to the updated estimated height and the estimated height, and the updated initial calibration height is used as the target height.

5. The TDOA and AOA fusion positioning method of claim 4, wherein, updating the initial calibrated altitude according to the estimated altitude and the updated estimated altitude: H' n = |H n - H n-1 | wherein n is an integer greater than 0, n represents the number of times of updating of iterative updating, H n represents the initial calibration height after the n times of updating, H n represents the estimated height after the n times of updating, H0 represents the estimated height.

6. The TDOA and AOA fusion positioning method of claim 5, wherein, updating estimated distances of N TDOA stations to the target based on the estimated distance or the updated estimated distance and the initial calibration height: where d n,i represents the estimated range of the ith TDOA station to the target after the nth update, d 0,i represents the estimated range of the ith TDOA station to the target, H0' represents an initial calibration height, which is equal to the estimated height.

7. The TDOA and AOA fusion positioning method of claim 6, wherein, Based on the updated estimated distances, update the time differences between N of the TDOA sites: wherein T n,ij represents the time difference between the ith (i = 1, 2,..., N) TDOA station and the jth (j = 1, 2,..., N) TDOA station after the nth update, d n,i represents the estimated distance of the ith TDOA station to the target after the nth update, d n,i represents the estimated distance of the ith TDOA station to the target after the nth update, and c is the speed of light, c ≈ 3 x 10 8 km / h.

8. The TDOA and AOA fusion positioning method of claim 7, wherein, Based on the updated time difference between N TDOA stations, an updated time difference matrix is obtained: where ΔT n denotes the time difference matrix after the n-th update.

9. The TDOA and AOA fusion positioning method of claim 4, wherein, The first set distance is 3 m.

10. The TDOA and AOA fusion positioning method of claim 1, wherein, The distance between any two TDOA stations is greater than or equal to 300 m.

11. The TDOA and AOA fusion positioning method of claim 1, wherein, The AOA stations are distributed in the area where the TDOA stations are distributed.

12. The TDOA and AOA fusion positioning method of claim 1, wherein, fusing the target two-dimensional coordinate and the target height to obtain a target three-dimensional coordinate: where P 3d represents the target three-dimensional coordinate, P 2d represents the target two-dimensional coordinate, H' represents the target height, The symbol represents the fusion of physics.

13. A TDOA and AOA fusion positioning system, characterized by The system can use the method of any one of claims 1-12. The target identification module: each TDOA station receives signals within its measurement range, and if a target signal is received, first target data is formed, which includes time information of the target signal received. The two-dimensional coordinate acquisition module: according to the first target data formed by N TDOA stations, an estimated two-dimensional coordinate is obtained. The estimated height acquisition module: based on the estimated two-dimensional coordinate, an AOA station is used to perform AOA measurement processing to obtain an estimated height, which is used as an initial calibration height. The distance estimation module: based on the estimated two-dimensional coordinate, the estimated distances between N TDOA stations and the target are obtained. The iterative calibration module: based on the estimated distances and the initial calibration height, the estimated distances between N TDOA stations and the target are iteratively updated to obtain a target two-dimensional coordinate and a target height. The coordinate conversion module: the target three-dimensional coordinate is obtained by fusing the target two-dimensional coordinate and the target height.

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