A multi-target registration method in bistatic passive cross location

Abstract

The application discloses a multi-target registration method in double-station passive cross positioning. Firstly, the virtual coordinates of targets are calculated respectively according to all angle measurement information of the main station and the auxiliary station; secondly, corresponding angle measurement lines are constructed according to the calculated virtual coordinates; thirdly, the distances D between all angle measurement lines of the auxiliary station and a certain angle measurement line of the main station are calculated, and the distance straight lines are determined; then, the intersection points of each distance straight line and the current angle measurement line and the distances SC between the intersection points and the main station are calculated; finally, the D / SC formed by the current angle measurement line of the main station and all angle measurement lines of the auxiliary station are calculated, and the minimum value of the D / SC is searched, and the angle measurement of the main station and the angle measurement of the auxiliary station corresponding to the minimum value are the angles of the same target relative to the two stations. The method realizes the information registration of the target by defining the opening angle of the shortest distance line segment between the angle measurement lines relative to the station, effectively improves the efficiency of the information registration, and has low complexity, so that the calculation time can be saved.

Description

Technical fields:

[0001] This invention belongs to the field of passive positioning technology. The main content is a multi-target registration method in dual-station passive cross-positioning. Dual-station passive cross-positioning is a widely used method in passive positioning systems. It uses high-precision direction-finding equipment to determine the direction of the target at multiple observation stations. When there is no direction-finding error, the intersection of the direction-finding lines is the position of the target. Background technology:

[0002] With the rapid development of optoelectronic countermeasures technology and its widespread use in modern warfare, both sides have increasingly higher requirements for the concealment of weapon systems. Infrared reconnaissance and warning systems, with their advantages of wide detection range, high positioning accuracy, good concealment, strong anti-jamming capability, and long operating range, have become the main technical means of military target warning. However, infrared warning systems have difficulty obtaining the distance and spatial location information of targets and cannot directly locate them, thus limiting their effectiveness. Therefore, improving the passive positioning technology of infrared warning systems has become particularly important. In passive positioning technology, the registration effect of multi-target information between two stations directly affects the accuracy of positioning. Since each observation station introduces north-pointing error, leveling error, and site error, and the observation station introduces angular measurement error in target observation, improving the registration rate of multi-target information between two stations has become a challenging task.

[0003] The main registration methods for multiple targets between two stations are: minimum distance method and data association method.

[0004] The minimum distance algorithm uses the geometric distance information of the intersection points between the direction finding lines of different observation stations to correlate azimuth data. That is, among the intersection points calculated by each pair of observation stations, the closest point is most likely to correspond to the same target. However, due to the influence of the geometric positions of the observation stations and the target, as well as the lateral errors, north-pointing errors, and site errors of the observation stations, the correlation area formed by the smallest distance point does not necessarily correspond to the correct target. Therefore, the minimum distance algorithm has a relatively high probability of incorrect correlation.

[0005] The maximum likelihood method is a mainstream algorithm in data association. It involves dividing all azimuth angles measured by each observation station into several candidate association combinations according to their source, calculating the likelihood function of each candidate association combination, and using three-dimensional allocation to find the optimal candidate association combination. The probability of correctness is relatively high. However, when the number of observation stations and targets is large, the amount of computation is also very large, increasing exponentially, making it unsuitable for real-time processing and engineering applications.

[0006] In summary, current passive positioning techniques for multi-target registration suffer from drawbacks such as high computational complexity, poor real-time performance, and low registration rate. The high computational complexity and poor real-time performance are due to the complexity of the algorithms, which increases significantly when the number of targets is large. The low registration rate is caused by various measurement errors that prevent current algorithms from accurately matching targets. Therefore, the algorithm based on the minimum master station angle proposed in this invention is of great significance for achieving target registration in situations with multiple targets. Summary of the Invention:

[0007] To overcome the shortcomings of existing technologies, this invention provides a dual-station multi-target registration method with high registration rate and good real-time performance, so as to solve the problems of low registration rate and high difficulty in engineering application of existing technologies.

[0008] The main basis of this method is that when two observation stations simultaneously observe the same target, due to the existence of errors, the angle subtended by the main station corresponding to the minimum distance segment between two direction finding lines should be the minimum value of the angle subtended by the main station corresponding to the minimum distance segment between all the direction finding lines to be matched between the two stations, and less than the angle measurement error of the station. This method first defines the angle finding line corresponding to each angle measurement at the two stations. Then, relative to a certain angle finding line at each main station, it calculates the distances between all angle finding lines at the auxiliary station and the current angle finding line at the main station, and calculates the distance from the intersection point of each distance line with the current angle finding line at the main station to the main station, i.e., the distance from the perpendicular to the main station. Then, based on the angle finding line distances and the corresponding perpendicular distances to the main station, it calculates the angle subtended by the main station corresponding to the angle finding line distance. Finally, it finds the smallest angle subtended by the auxiliary station angle and the current main station angle pointing to the same target.

[0009] The above-mentioned objective of the present invention is achieved through the following technical solution:

[0010] A multi-target registration method in dual-station passive cross-location. It includes the following steps:

[0011] (1) Calculate the virtual coordinates of the target in the three-dimensional rectangular coordinate system corresponding to each measurement angle of the two stations:

[0012] T x = d*cos(e)*cos(a)

[0013] T y = d*cos(e)*sin(a)

[0014] T z =d*sin(e)

[0015] Assume the distance from the target to the station is d, and a and e are the azimuth and elevation angles, respectively. (T) x ,T y ,T z() represents the virtual coordinates of the target in a three-dimensional Cartesian coordinate system;

[0016] (2) Define the angle measurement line corresponding to each observation angle at the two measurement stations:

[0017]

[0018]

[0019] in, Let T be the angle measurement vectors of target i at the main station and target j at the auxiliary station, respectively; 1i (x, y, z) represent the virtual coordinates of the main station target i in a three-dimensional rectangular coordinate system, and T 2j (x, y, z) represent the virtual coordinates of target j at the auxiliary station in a three-dimensional Cartesian coordinate system. When calculating the virtual coordinates, it is assumed that the distance d from the target to the station is 1. and S1(x,y,z) and S2(x,y,z) are the unit direction vectors of the angle measurement lines, respectively, and S1(x,y,z) and S2(x,y,z) are the position coordinates of the main station and the auxiliary station in the three-dimensional rectangular coordinate system, respectively; the coordinate values ​​of the measuring station and the target need to be in the same three-dimensional rectangular coordinate system;

[0020] (3) For the main station's angle measurement line Calculate all angle lines of the auxiliary station The distance D between them j :

[0021]

[0022] Among them, D j Let A be the distance between all angle measurement lines of the auxiliary station and the current angle measurement line of the main station (j = 1, 2, 3…); A and A' are any points on the two angle measurement lines, respectively. Let A be the vector formed by points A and A'.

[0023] (4) Calculate all angle measurement lines of the auxiliary station And the current angle measurement line of the main station The shortest distance line segment between and the current angle measurement line of the main station The distance sc from the intersection point to the main station:

[0024]

[0025]

[0026]

[0027]

[0028] Among them, S m(x,y,z) is the straight line expression for the diagonal line at the main station, S s (x,y,z) is the linear expression of the angle measurement line of the auxiliary station. By combining the above formulas, we can obtain the distance sc from the intersection point of the distance segment between the two angle measurement lines and the angle measurement line of the main station to the main station, and the distance tc from the intersection point of the distance segment between the two angle measurement lines and the angle measurement line of the auxiliary station to the auxiliary station.

[0029] (5) For the main station angle measurement line L mi Calculate the angles subtended by all angle measurement lines of the auxiliary station and their shortest distance segments relative to the main station, and find the minimum subtended angle, which should be less than the angle measurement error of the main station.

[0030]

[0031] θ min =min(θ) j (j=1,2,3…)

[0032] Where, θ j All angle measurement lines L of the auxiliary station sj The angle θ between the distance segment of the current angle measurement line from the main station and the main station. min The minimum subtended angle; the angle measurements taken by the main station and the auxiliary station corresponding to the minimum subtended angle point to the same target.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1) The registration principle based on the minimum opening angle is set based on actual engineering measurement errors, and the calculation accuracy is relatively high;

[0035] 2) The calculation method is relatively simple and easy to apply in engineering. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating the implementation of the present invention.

[0037] Figure 2 This is a schematic diagram of the angle subtended by the shortest distance line segment between the auxiliary station's angle measuring line and the main station's angle measuring line, as mentioned in this invention, relative to the main station. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Several parameters are involved, and these parameters need to be adjusted for specific processing environments to achieve good performance.

[0039] Simulation environment: Matlab 2019a;

[0040] Dual-station simulation location information: The positions of the two stations are fixed. The main station's coordinates in the rectangular coordinate system are (1km,0,0), and the auxiliary station's coordinates in the rectangular coordinate system are (5km,0,0). The measurement accuracy of each station is 3mrad. The targets are arranged in a line with a spacing d. The slope of the line connecting the two stations in the line is 30°.

[0041] Target simulation information:

[0042] Linear formation: Assuming the positions of the 5 targets are as follows:

[0043] Target 1 (3km, 10km, 3km);

[0044] Target 2

[0045] Target 3

[0046] Target 4

[0047] Target 5

[0048] Simulation method: Assuming that the measurement errors of the two stations are normally distributed random errors and the measurement accuracy of the stations is 3 mrad, 1000 Monte Carlo simulations were performed on the entire association process. Table 1 shows the correct association probability for different spacings and different numbers of targets.

[0049] Table 1. Registration accuracy of multiple targets at different spacings

[0050]

Claims

1. A multi-target registration method in dual-station passive cross-location, wherein the dual stations include a primary station and an auxiliary station, characterized in that... The method includes the following steps: (1) Calculate the virtual coordinates of the target in the three-dimensional rectangular coordinate system corresponding to each measurement angle of the dual stations: T x =d*cos(e)*cos(a) T y =d*cos(e)*sin(a) T z =d*sin(e) Assume the distance from the target to the two stations is d, and a and e are the measured azimuth and elevation angles, respectively. (T) x ,T y ,T z () represents the virtual coordinates of the target in a three-dimensional Cartesian coordinate system; (2) Define the angle measurement line corresponding to each observation angle of the two stations: in, Let T be the angle measurement vectors of target i at the main station and target j at the auxiliary station, respectively; 1i (x, y, z) represent the virtual coordinates of the main station target i in a three-dimensional rectangular coordinate system, and T 2j (x, y, z) represent the virtual coordinates of target j at the auxiliary station in a three-dimensional Cartesian coordinate system. When calculating the virtual coordinates, it is assumed that the distance d from the target to the station is 1. and S1(x,y,z) and S2(x,y,z) are the unit direction vectors of the angle measurement lines, respectively, and S1(x,y,z) and S2(x,y,z) are the position coordinates of the main station and the auxiliary station in the three-dimensional rectangular coordinate system, respectively; the coordinate values ​​of the two stations and the target need to be in the same three-dimensional rectangular coordinate system; (3) For the main station's angle measurement line Calculate all angle lines of the auxiliary station The distance D between them j : Among them, D j Let A be the distance between all angle measurement lines of the auxiliary station and the current angle measurement line of the main station (j = 1, 2, 3…); A and A' are any points on the two angle measurement lines, respectively. Let A be the vector formed by points A and A'. (4) Calculate all angle measurement lines of the auxiliary station And the current angle measurement line of the main station The shortest distance line segment between and the current angle measurement line of the main station The distance sc from the intersection point to the main station: Among them, S m (x,y,z) is the straight line expression for the diagonal line at the main station, S s (x,y,z) is the linear expression of the angle measurement line of the auxiliary station. By combining the above formulas, we can obtain the distance sc from the intersection point of the distance segment between the two angle measurement lines and the angle measurement line of the main station to the main station, and the distance tc from the intersection point of the distance segment between the two angle measurement lines and the angle measurement line of the auxiliary station to the auxiliary station. (5) For the main station angle measurement line L mi Calculate the angles subtended by all angle measurement lines of the auxiliary station and their shortest distance segments relative to the main station, and find the minimum subtended angle, which should be less than the angle measurement error of the main station. i min =min(θ j ) (j=1,2,3…) Where, θ j All angle measurement lines L of the auxiliary station sj The angle subtended by the distance segment from the current angle measurement line of the main station relative to the main station; θ min The minimum subtended angle; the angle measurements taken by the main station and the auxiliary station corresponding to the minimum subtended angle point to the same target.

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