Forward scatter radar network target three-dimensional spatial position estimation method and storage medium

Abstract

The present invention belongs to the field of radar detection technology, and discloses a forward scatter radar network target three-dimensional spatial position estimation method and storage medium, including: firstly establishing a coordinate system, determining the positions of a transmitting station and a receiving station, solving the plane equation formed by the connecting line of the transmitting station and the receiving station, determining the x and y coordinate axes in the two-dimensional plane, and converting the three-dimensional coordinates of the transmitter and the receiver into two-dimensional coordinates in the same plane; then constructing a parameter estimation equation based on the geometric structure of the forward scatter radar network, and solving the equation; finally, converting the obtained estimated value of the target position in the two-dimensional plane into three-dimensional space to obtain the target position estimation result. The present invention is based on the forward scatter radar network target three-dimensional spatial position estimation method, which can be applied to the target detection of the forward scatter radar network. The present invention can improve the real-time positioning efficiency in forward scatter radar target detection; and reduce the energy consumption of long-distance early warning in radar target detection.

Description

Technical Field

[0001] The invention belongs to the field of radar detection technology, and in particular relates to a forward scattering radar network target three-dimensional space position estimation method and a storage medium. Background Art

[0002] At present, forward scatter radar is a dual / multi-base radar with advantages such as anti-stealth, anti-interference, and strong survivability. In the existing parameter estimation algorithm for the forward scatter radar system, it is necessary to detect the arrival azimuth or elevation of the forward scatter echo, and it also needs to be accumulated for a long time, and the actual application cost-effectiveness is high. In the forward scatter radar system, when the target is close to the baseline and the dual-base angle is close to 180o, the target will produce a relatively large disturbance to the direct wave. By measuring the waveform of the disturbance, the time when the target crosses the baseline can be obtained. Relevant literature has confirmed this. Through continuous observation, multiple observation equations can be established, and the three-dimensional spatial coordinates of the target can be obtained by combining the earth coordinate model.

[0003] Through the above analysis, the problems and defects of the existing technology are: the existing algorithms are cost-effective and require a long time to accumulate.

[0004] The difficulty in solving the above problems and defects is: for target detection using space resources such as navigation satellites as external radiation sources, the existing method directly uses target echoes for target detection, which requires the target echo signal-to-noise ratio to meet the detection requirements. Therefore, a large-aperture antenna and long-term accumulation are required to increase the echo power and signal-to-noise ratio. The cost of antennas and signal processing equipment is greatly increased, and the effective range is still limited, making it difficult to play a role in practical applications.

[0005] The significance of solving the above problems and defects is that the disturbance of the target on the signal can be measured by using only a very small antenna, without the need for long-term accumulation and large-aperture antenna angle measurement, which greatly reduces the cost and only requires a ground receiving array, which is very easy to deploy. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a method for estimating the three-dimensional spatial position of a forward scatter radar network target. The present invention is based on the forward scatter radar network architecture of satellite radiation sources. When a target enters the observation airspace, the receiver measures the moment when the target in uniformly accelerated linear motion crosses multiple baselines, and converts the coordinates of the transmitting station and the receiving station into two-dimensional coordinates. The parameter estimation algorithm is applied to obtain the coordinates in the two-dimensional plane, and then the result is converted into three-dimensional space, which can timely provide an available three-dimensional spatial target position estimation value.

[0007] The present invention is implemented as follows: a forward scatter radar network target three-dimensional spatial position estimation method, the forward scatter radar network target three-dimensional spatial position estimation method comprising:

[0008] First, a coordinate system is established to determine the positions of the transmitting station and the receiving station, the plane equation formed by the line connecting the transmitting station and the receiving station is solved, the x and y coordinate axes in the two-dimensional plane are determined, and the three-dimensional coordinates of the transmitter and the receiver are converted into two-dimensional coordinates in the same plane. This process provides coordinate conversion between three-dimensional space and two-dimensional plane to obtain known quantities;

[0009] Then, a parameter estimation equation is constructed based on the geometric structure of the forward scatter radar network, and the equation is solved to obtain the position estimation value of the target in the two-dimensional plane, and the coordinates of the detected object in the two-dimensional plane are calculated;

[0010] Finally, the estimated value of the target position in the two-dimensional plane is converted to the three-dimensional space to obtain the final estimated result of the target position, that is, the estimated position coordinates are converted to the actual three-dimensional space.

[0011] Furthermore, the forward scatter radar network target three-dimensional spatial position estimation method comprises the following specific processes:

[0012] Step 1: define the coordinate system and determine the locations of the radar transmitting and receiving stations;

[0013] Step 2: Solve the plane equation formed by the line connecting the radar transmitting station and the receiving station to determine the equations of the x and y coordinate axes in the two-dimensional plane;

[0014] Step 3: Convert the three-dimensional coordinates of the transmitting station and the receiving station into two-dimensional coordinates and establish the target parameter estimation equation;

[0015] Step 4: Solve the target parameter estimation equation to obtain the target two-dimensional initial position coordinates, and convert the estimated value of the target position in the two-dimensional plane into three-dimensional space.

[0016] Furthermore, in step 1, the specific process of defining the coordinate system is as follows:

[0017] The forward scatter radar network uses satellites as radiation sources, and the receiving stations are arranged in a rectangular array. When a target flies over the sky, it is assumed that the target moves in a uniformly accelerated straight line. The target continuously crosses the baselines formed by multiple receiving stations and transmitting stations. Since the target moves in a straight line, the baselines crossed are in the same plane. The corresponding transmitting stations and receiving stations are numbered from small to large according to the crossing order. The transmitting stations are numbered T1, T2, ..., and the receiving stations are numbered R1, R2, ...;

[0018] The receiving station corresponding to the first baseline crossed by the target is set as R1, and is taken as the origin O. The due east direction is the x-axis, the due north direction is the y-axis, the x and y axes are in the horizontal plane, and the z axis is perpendicular to the horizontal plane and upward, to establish a Cartesian coordinate system.

[0019] Furthermore, in step 1, the specific process of determining the positions of the radar transmitting station and the receiving station is as follows:

[0020] Assume that there are K receiving stations and N transmitting stations corresponding to the target crossing the baseline. According to the time sequence of the target crossing, the coordinates of the transmitting station are T n (x tn ,y tn ,z tn ), (n=1,2,…N), the receiving station coordinate is R k (x rk ,y rk ,z rk ), (k=1,2,…K).

[0021] Furthermore, in step 2, the plane equation formed by the line connecting the radar transmitting station and the receiving station is solved, and the specific process is:

[0022] The coordinates of three points in the plane are known to be R k1 (x rk1 ,y rk1 ,z rk1 ), R k2 (x rk2 ,y rk2 ,z rk2 ), T n1 (x tn1 ,y tn1 ,z tn1 ), k1, k2, n1 are the available transmitting and receiving station numbers, and the plane equation can be determined as:

[0023] ax+by+cz+d=0 (1)

[0024] Where a = y rk1 (z rk2 -z tn1 )+y rk2 (z tn1 -z rk1 )+y tn1 (z rk1 -z rk2 );

[0025] b=z rk1 (x rk2 -x tn1 )+z rk2 (x tn1 -x rk1 )+z tn1 (x rk1 -x rk2 );

[0026] c=x rk1 (y rk2 -y tn1 )+x rk2 (y tn1-y rk1 )+x tn1 (y rk1 -y rk2 );

[0027] d=-x rk1 (y rk2 z tn1 -y tn1 z rk2 )-x rk2 (y tn1 z rk1 -y rk1 z tn1 )-x tn1 (y rk1 z rk2 -y rk2 z rk1 );

[0028] Determine the equations of the x and y coordinate axes in the two-dimensional plane. The specific process is:

[0029] Take R1 as the origin O and select receiving stations R1, R2…R K The straight line is taken as the x-axis, and two points (x rk1 ,y rk1 ,0)、(x rk2 ,y rk2 ,0) form the direction vector M1 of the straight line = (x rk2 -x rk1 ,y rk2 -y rk1 ,0);

[0030] The equation of the line on the x-axis is:

[0031]

[0032] The y-axis passes through point R1(0,0,0). Suppose it also passes through point C(x C ,y C ,z C ), then the direction vector is M2=(x C ,y C ,z C ), the equation of the straight line on the y-axis can be expressed as:

[0033]

[0034] Since the x-axis is perpendicular to the y-axis, the inner product of their direction vectors is zero: M1*M2=0. Since point C belongs to the plane formed by x and y, then: a×x C +b×y C +c×z C+d=0; As long as the condition that point C is on the y-axis is satisfied, its specific position is not important, so it is assumed that the x-axis coordinate of point C is 1, and the above problem is converted into the solution of a two-variable linear equation, and the solution is:

[0035]

[0036] Furthermore, in step 3, the three-dimensional coordinates of the transmitting station and the receiving station are converted into two-dimensional coordinates. The specific process is as follows:

[0037] Calculate the distance from each point on the plane to the x and y axes, which is the absolute value of the corresponding two-dimensional coordinates, and determine the quadrant in which the point is located based on the angle between the vector formed by each point and the origin and the x axis to determine the coordinate sign;

[0038] Taking the calculation of the x-axis coordinate as an example, the distance calculation process from a point to a straight line is as follows:

[0039] The equation of the straight line along the y-axis is known to be:

[0040] Assume that the foot coordinates of a point (x, y, z) outside the line are D(x d ,y d ,z d ),set up Therefore

[0041] Since the dot product of the direction vector of the perpendicular line and the direction vector of the y-axis is zero, we can get

[0042] Therefore, the perpendicular coordinates can be solved;

[0043] The distance from a point to a line is: That is the x-axis coordinate of the point;

[0044] The calculation of the y-axis coordinate is similar to the above process.

[0045] Furthermore, in step 3, the specific process of establishing the target parameter estimation equation is as follows:

[0046] Based on the system structure formed by the target continuously crossing the baseline, the parameter estimation equation containing the initial position of the target is obtained. The parameters required in the equation include the two-dimensional station information and the time when the target crosses the baseline;

[0047] Assume that the target moves in a uniformly accelerated straight line in the xy plane with a velocity of v and an acceleration of a. The initial target position coordinates are (x0, y0), and the velocities and accelerations in the x and y directions are v and a respectively. x 、v y 、a x 、a y ; After time t, the position of the target is expressed as:

[0048]

[0049] Let (n,k) represent the nth transmitting station and the kth receiving station, and L nk Indicates the baseline between the nth transmitting station and the kth receiving station. The time when the target crosses the first baseline is taken as the starting time. The target crosses the baseline L nk The time is t nk , we can get the relationship:

[0050]

[0051] Among them, t nk It represents the time required for the target to move from the initial position to the current position. In actual measurement, the time point when the target crosses each baseline can be measured, and the time measured when the target crosses the first baseline can be subtracted to obtain the time t when the target crosses the baseline in the same sense. nk , which is equivalent to the initial moment, i.e., moment 0, when the target is located on the first baseline;

[0052] The above formula is written in matrix form as:

[0053]

[0054] Assume that there are P nodes available, if P ≥ N U , N U is the number of unknowns, then the unknown vector can be solved by the linear equation system:

[0055]

[0056] Among them, from the above analysis, we can know that t n1k1 =0,(x rkp ,y rkp )、(x tnp ,y tnp ) are the two-dimensional coordinates of the receiving station and the transmitting station corresponding to the target's current crossing of the baseline, p = 1, 2, …, P.

[0057] Furthermore, in step 4, the target parameter estimation equation is solved to obtain the target two-dimensional initial position coordinates, and the specific process is as follows:

[0058] Based on the established parameter estimation equation, the P×6 matrix C is defined as:

[0059]

[0060] The estimation equation of the target motion parameters is given by:

[0061]

[0062] in,

[0063] Right now

[0064] x0=[(C T C) -1 C T F]1 (11)

[0065] y0=[(C T C) -1 C T F]2 (12)

[0066] Furthermore, in step 4, the estimated value of the target position in the two-dimensional plane is converted into three-dimensional space. The specific process is as follows:

[0067] Calculate the direction angle of the x-axis and y-axis direction vectors in the two-dimensional plane, where the direction vector of the x-axis is M1=(x rk2 -x rk1 ,y rk2 -y rk1 ,0), the direction vector of the y-axis is M2=(x C ,y C ,z C ), so the direction angles are:

[0068]

[0069]

[0070] Assuming that the initial position of the target in three-dimensional space is (x'0, y'0, z'0), based on the initial position of the target in the two-dimensional plane (x0, y0), we can get:

[0071]

[0072] Right now

[0073]

[0074] Another object of the present invention is to provide a storage medium for receiving a program input by a user, wherein the stored computer program enables an electronic device to execute the forward scatter radar network target three-dimensional spatial position estimation method comprising the following steps:

[0075] First, a coordinate system is established to determine the positions of the transmitting station and the receiving station, the plane equation formed by the line connecting the transmitting station and the receiving station is solved, the x and y coordinate axes in the two-dimensional plane are determined, and the three-dimensional coordinates of the transmitter and the receiver are converted into two-dimensional coordinates in the same plane;

[0076] Then, a parameter estimation equation is constructed based on the geometric structure of the forward scattering radar network and the equation is solved; finally, the estimated value of the target position in the two-dimensional plane is converted into three-dimensional space to obtain the target position estimation result.

[0077] Combining all the above technical solutions, the advantages and positive effects of the present invention are as follows: the target three-dimensional spatial position estimation method based on the forward scattering radar network of the present invention has the characteristics of simple use, real-time and high efficiency, and can be used as an effective early warning means, solving the problems of high cost-effectiveness and long-term accumulation of existing algorithms. The present invention uses the crossing time measured by multiple receivers and the location information of the transmitting station and the receiving station to estimate the three-dimensional spatial position of the target. The present invention is aimed at the area covered by the connection line between the satellite radiation source and the receiver array. When the target flies across multiple baselines, the time of crossing each baseline is recorded, and the station address information is converted from three-dimensional to two-dimensional, so that the position of the target crossing the first baseline can be solved in the observation plane in space, and then the estimation result is converted to three-dimensional space to obtain the three-dimensional coordinates of the target.

[0078] At the same time, the target three-dimensional spatial position estimation method based on the forward scatter radar network of the present invention can be applied to the target detection of the forward scatter radar network. The present invention can improve the real-time positioning efficiency in forward scatter radar target detection; reduce the energy consumption of long-distance early warning in radar target detection; and be extended to forward scatter radar networks on different platforms such as the ground, sea, and air. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 It is a flow chart of a method for estimating the three-dimensional spatial position of a forward scattering radar network target provided by an embodiment of the present invention.

[0080] Figure 2 It is a structural diagram of a defined coordinate system provided by an embodiment of the present invention.

[0081] Figure 3 1 is a diagram of a radar system architecture provided by an embodiment of the present invention.

[0082] Figure 4 It is a diagram of real coordinates and estimated coordinates in a simulation example provided by an embodiment of the present invention.

[0083] Figure 5 It is a coordinate estimation error diagram in a simulation example provided by an embodiment of the present invention.

[0084] Figure 6 It is a schematic diagram of the three-dimensional spatial position estimation process of a forward scatter radar network target provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0085] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0086] In view of the problems existing in the prior art, the present invention provides a forward scattering radar network target three-dimensional spatial position estimation method and storage medium, and the present invention is described in detail below with reference to the accompanying drawings.

[0087] The method for estimating the three-dimensional spatial position of a forward scattering radar network target provided by the present invention can also be implemented by other steps by ordinary technicians in the industry. Figure 1 The forward scattering radar network target three-dimensional spatial position estimation method provided by the present invention is only a specific embodiment.

[0088] The method for estimating the three-dimensional spatial position of a forward scattering radar network target provided by an embodiment of the present invention includes:

[0089] First, a coordinate system is established to determine the positions of the transmitting station and the receiving station, the plane equation formed by the line connecting the transmitting station and the receiving station is solved, the x and y coordinate axes in the two-dimensional plane are determined, and the three-dimensional coordinates of the transmitter and the receiver are converted into two-dimensional coordinates in the same plane; then, a parameter estimation equation is constructed based on the geometric structure of the forward scattering radar network and the equation is solved; finally, the estimated value of the target position in the two-dimensional plane is converted into three-dimensional space to obtain the target position estimation result.

[0090] like Figure 1 As shown, the forward scatter radar network target three-dimensional spatial position estimation method provided by the embodiment of the present invention specifically includes the following steps:

[0091] S101: define the coordinate system and determine the positions of the radar transmitting station and receiving station;

[0092] S102: Solve the plane equation formed by the line connecting the radar transmitting station and the receiving station to determine the straight line equations of the x and y coordinate axes in the two-dimensional plane;

[0093] S103: converting the three-dimensional coordinates of the transmitting station and the receiving station into two-dimensional coordinates, and establishing a target parameter estimation equation;

[0094] S104: Solve the target parameter estimation equation to obtain the target two-dimensional initial position coordinates, and convert the estimated value of the target position in the two-dimensional plane into three-dimensional space.

[0095] In S101 provided in the embodiment of the present invention, the specific process of defining the coordinate system is as follows:

[0096] The forward scatter radar network uses satellites as radiation sources, and the receiving stations are arranged in a rectangular array, such as Figure 2As shown; when a target flies over the sky, it is assumed that the target moves in a straight line with uniform acceleration. The target continuously crosses the baselines formed by multiple receiving stations and transmitting stations. Since the target moves in a straight line, the baselines crossed are in the same plane. The corresponding transmitting stations and receiving stations are numbered from small to large in the order of crossing. The transmitting stations are numbered T1, T2, ..., and the receiving stations are numbered R1, R2, ...

[0097] The receiving station corresponding to the first baseline crossed by the target is set as R1, and is taken as the origin O. The due east direction is the x-axis, the due north direction is the y-axis, the x and y axes are in the horizontal plane, and the z axis is perpendicular to the horizontal plane and upward, to establish a Cartesian coordinate system.

[0098] In S101 provided in the embodiment of the present invention, the specific process of determining the positions of the radar transmitting station and the receiving station is as follows:

[0099] Assume that there are K receiving stations and N transmitting stations corresponding to the target crossing the baseline. According to the time sequence of the target crossing, the coordinates of the transmitting station are T n (x tn ,y tn ,z tn ), (n=1,2,…N), the receiving station coordinate is R k (x rk ,y rk ,z rk ), (k=1,2,…K).

[0100] In S102 provided in the embodiment of the present invention, the plane equation formed by the line connecting the radar transmitting station and the receiving station is solved, and the specific process is:

[0101] The coordinates of three points in the plane are known to be R k1 (x rk1 ,y rk1 ,z rk1 ), R k2 (x rk2 ,y rk2 ,z rk2 ), T n1 (x tn1 ,y tn1 ,z tn1 ), k1, k2, n1 are the available transmitting and receiving station numbers, and the plane equation can be determined as:

[0102] ax+by+cz+d=0 (1)

[0103] Where a = y rk1 (z rk2 -z tn1 )+y rk2 (z tn1 -z rk1 )+ytn1 (z rk1 -z rk2 );

[0104] b=z rk1 (x rk2 -x tn1 )+z rk2 (x tn1 -x rk1 )+z tn1 (x rk1 -x rk2 );

[0105] c=x rk1 (y rk2 -y tn1 )+x rk2 (y tn1 -y rk1 )+x tn1 (y rk1 -y rk2 );

[0106] d=-x rk1 (y rk2 z tn1 -y tn1 z rk2 )-x rk2 (y tn1 z rk1 -y rk1 z tn1 )-x tn1 (y rk1 z rk2 -y rk2 z rk1 ).

[0107] In S102 provided in the embodiment of the present invention, the equations of the x and y coordinate axes in the two-dimensional plane are determined, and the specific process is:

[0108] Take R1 as the origin O and select receiving stations R1, R2…R K The straight line is taken as the x-axis, and two points (x rk1 ,y rk1 ,0)、(x rk2 ,y rk2 ,0) form the direction vector M1 of the straight line = (x rk2 -x rk1 ,y rk2 -y rk1 ,0);

[0109] The equation of the line on the x-axis is:

[0110]

[0111] The y-axis passes through point R1(0,0,0). Suppose it also passes through point C(x C ,y C ,z C ), then the direction vector is M2=(x C ,y C ,z C ), the equation of the straight line on the y-axis can be expressed as:

[0112]

[0113] Since the x-axis is perpendicular to the y-axis, the inner product of their direction vectors is zero: M1*M2=0. Since point C belongs to the plane formed by x and y, then: a×x C +b×y C +c×z C +d=0. As long as the condition that point C is on the y-axis is satisfied, its specific position is not important, so we can assume that the x-axis coordinate of point C is 1, and convert the above problem into solving a two-variable linear equation, and the solution is:

[0114]

[0115] In S103 provided in the embodiment of the present invention, the three-dimensional coordinates of the transmitting station and the receiving station are converted into two-dimensional coordinates. The specific process is as follows:

[0116] Calculate the distance from each point on the plane to the x and y axes, which is the absolute value of the corresponding two-dimensional coordinates, and determine the quadrant in which the point is located based on the angle between the vector formed by each point and the origin and the x-axis to determine the coordinate sign.

[0117] Here, taking the calculation of the x-axis coordinate as an example, the distance calculation process from a point to a straight line is as follows:

[0118] The equation of the straight line along the y-axis is known to be:

[0119] Assume that the foot coordinates of a point (x, y, z) outside the straight line (the point that needs to be converted from 3D coordinates to 2D coordinates) on the straight line are D(x d ,y d ,z d ),set up Therefore

[0120] Since the dot product of the direction vector of the perpendicular line and the direction vector of the y-axis is zero, we can get

[0121] Therefore, the perpendicular coordinates can be solved;

[0122] The distance from a point to a line is: This is the x-axis coordinate of the point.

[0123] The calculation of the y-axis coordinate is similar to the above process.

[0124] In S103 provided in the embodiment of the present invention, the specific process of establishing the target parameter estimation equation is as follows:

[0125] Based on the system structure formed by the target continuously crossing the baseline, the parameter estimation equation containing the initial position of the target is obtained. The parameters required in the equation include the two-dimensional site information and the time when the target crosses the baseline.

[0126] Assume that the target moves in a uniformly accelerated straight line in the xy plane, with a velocity of v and an acceleration of a. The initial target position coordinates are (x0, y0), such as Figure 3 As shown, the velocity and acceleration in the x and y directions are v respectively. x 、v y 、a x 、a y After time t, the position of the target is expressed as:

[0127]

[0128] Let (n,k) represent the nth transmitting station and the kth receiving station, and L nk The target crosses the first baseline as the starting time. nk The time is t nk , we can get the relationship:

[0129]

[0130] Here nk It represents the time required for the target to move from the initial position to the current position. In actual measurement, the time point when the target crosses each baseline can be measured, and the time measured when the target crosses the first baseline can be subtracted to obtain the time t when the target crosses the baseline in the same sense. nk , which is equivalent to the initial moment, i.e., moment 0, when the target is located on the first baseline.

[0131] The above formula is written in matrix form as:

[0132]

[0133] Assume that there are P nodes available, if P ≥ N U , N U is the number of unknowns, then the unknown vector can be solved by the linear equation system:

[0134]

[0135] Among them, from the above analysis, we can know that t n1k1=0,(x rkp ,y rkp )、(x tnp ,y tnp ) are the two-dimensional coordinates of the receiving station and the transmitting station corresponding to the target's current crossing of the baseline, p = 1, 2, …, P.

[0136] In S104 provided in the embodiment of the present invention, the target parameter estimation equation is solved to obtain the target two-dimensional initial position coordinates, and the specific process is as follows:

[0137] Based on the established parameter estimation equation, the P×6 matrix C is defined as:

[0138]

[0139] The estimation equation of the target motion parameters is given by:

[0140]

[0141] in,

[0142] Right now

[0143] x0=[(C T C) -1 C T F] 11 (11)

[0144] y0=[(C T C) -1 C T F] 21 (12).

[0145] In S104 provided in the embodiment of the present invention, the estimated value of the target position in the two-dimensional plane is converted into a three-dimensional space. The specific process is as follows:

[0146] Calculate the direction angle of the x-axis and y-axis direction vectors in the two-dimensional plane, where the direction vector of the x-axis is M1=(x rk2 -x rk1 ,y rk2 -y rk1 ,0), the direction vector of the y-axis is M2=(x C ,y C ,z C ), so the direction angles are:

[0147]

[0148]

[0149] Assuming that the initial position of the target in three-dimensional space is (x'0, y'0, z'0), based on the initial position of the target in the two-dimensional plane (x0, y0), we can get:

[0150]

[0151] Right now

[0152]

[0153] The technical solution of the present invention is described in detail below in conjunction with simulation experiments.

[0154] The effect of the present invention can be illustrated by simulation experiments. The simulation conditions are set as follows: assuming that the aircraft target continuously crosses six baselines, each measurement error obeys a zero-mean Gaussian distribution, as shown in Table 1.

[0155] Table 1 Simulation system parameters

[0156]

[0157] In the simulation, due to the actual station layout factors, the height of the receiving station may not be exactly the same, and the line connecting the transmitting station and the receiving station is not in the same plane. The position errors of the receiving station introduced are 0.0352 and 0.0352m, respectively, and the position errors of the transmitting station are 296.0228 and 296.0228m, respectively. The above values ​​mean the distance between the two-dimensional coordinate position and the actual three-dimensional space position. The error of this magnitude is acceptable and can be converted into two-dimensional coordinates according to the coordinate conversion method described in the present invention.

[0158] The number of Monte Carlo simulations is 1000. Figure 4 The actual target position and the target position obtained in each simulation are shown. Figure 5 The estimated error of the target initial position in each simulation (the absolute value of the difference between the true value and the estimated value) is shown, and the root mean square error of the position estimation of each point is summarized in Table 2. It can be seen that the initial position estimation accuracy obtained by the method of the present invention can meet the early warning requirements.

[0159] Table 2 Target and baseline intersection points and estimated root mean square error

[0160]

[0161] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods are implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0162] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for estimating the three-dimensional spatial position of a target in a forward scatter radar network, characterized in that: The forward scattering radar network target three-dimensional space position estimation method comprises: First, a coordinate system is established to determine the positions of the transmitting station and the receiving station, the plane equation formed by the line connecting the transmitting station and the receiving station is solved, the x and y coordinate axes in the two-dimensional plane are determined, and the three-dimensional coordinates of the transmitter and the receiver are converted into two-dimensional coordinates in the same plane; Then, the parameter estimation equations are constructed based on the geometric structure of the forward scatter radar network and the equations are solved; Finally, the estimated value of the target position in the two-dimensional plane is converted into three-dimensional space to obtain the target position estimation result; The specific process of establishing the target parameter estimation equation is as follows: Based on the system structure formed by the target continuously crossing the baseline, the parameter estimation equation containing the initial position of the target is obtained. The parameters required in the equation include the two-dimensional station information and the time when the target crosses the baseline; The target moves in a uniformly accelerated straight line in the xy plane with a velocity of v and an acceleration of a. The initial target position coordinates are (x0, y0), and the velocity and acceleration in the x and y directions are v and a respectively. x 、v y 、a x 、a y ; After time t, the position of the target is expressed as: Let (n,k) represent the nth transmitting station and the kth receiving station, and L nk Indicates the baseline between the nth transmitting station and the kth receiving station. The time when the target crosses the first baseline is taken as the starting time. The target crosses the baseline L nk The time is t nk , we get the relationship: Among them, t nk It represents the time required for the target to move from the initial position to the current position. In actual measurement, the time point when the target crosses each baseline is measured, and the time measured when the target crosses the first baseline is subtracted to obtain the time t when the target crosses the baseline in the same sense. nk , which is equivalent to the initial moment, i.e., moment 0, when the target is located on the first baseline; The above formula is written in matrix form as: There are P nodes available, if P ≥ N U , N U is the number of unknowns, then the unknown vector is solved by the linear equation system: Among them, from the above analysis, we know that the intersection of the target and the first baseline is the starting time, that is, are the two-dimensional coordinates of the receiving station and the transmitting station corresponding to the current baseline crossed by the target, p=1,2,…,P.

2. The method for estimating the three-dimensional spatial position of a forward scatter radar network target as claimed in claim 1, characterized in that: The forward scattering radar network target three-dimensional spatial position estimation method, the specific process is: Step 1: define the coordinate system and determine the locations of the radar transmitting and receiving stations; Step 2: Solve the plane equation formed by the line connecting the radar transmitting station and the receiving station to determine the equations of the x and y coordinate axes in the two-dimensional plane; Step 3: Convert the three-dimensional coordinates of the transmitting station and the receiving station into two-dimensional coordinates and establish the target parameter estimation equation; Step 4: Solve the target parameter estimation equation to obtain the target two-dimensional initial position coordinates, and convert the estimated value of the target position in the two-dimensional plane into three-dimensional space.

3. The method for estimating the three-dimensional spatial position of a forward scatter radar network target as claimed in claim 2, characterized in that: In step 1, the specific process of defining the coordinate system is as follows: The forward scatter radar network uses satellites as radiation sources, and the receiving stations are arranged in a rectangular array. When a target flies over the sky, the target moves in a uniformly accelerated straight line, and the target continuously crosses the baselines formed by multiple receiving stations and transmitting stations. Since the target moves in a straight line, the baselines crossed are in the same plane. The corresponding transmitting stations and receiving stations are numbered from small to large according to the crossing order. The transmitting stations are numbered T1, T2, ..., and the receiving stations are numbered R1, R2, ...; The receiving station corresponding to the first baseline crossed by the target is set as R1, and is taken as the origin O. The due east direction is the x-axis, the due north direction is the y-axis, the x and y axes are in the horizontal plane, and the z axis is perpendicular to the horizontal plane and upward, to establish a Cartesian coordinate system.

4. The method for estimating the three-dimensional spatial position of a forward scatter radar network target as claimed in claim 2, characterized in that: In step 1, the specific process of determining the positions of the radar transmitting station and the receiving station is as follows: there are K receiving stations and N transmitting stations corresponding to the target crossing the baseline. According to the time sequence of the target crossing, the coordinates of the transmitting station are T n (x tn ,y tn ,z tn ), n=1,2,…N, the receiving station coordinate is R k (x rk ,y rk ,z rk ), k=1,2,…K.

5. The method for estimating the three-dimensional spatial position of a forward scatter radar network target as claimed in claim 2, characterized in that: In step 2, solve the plane equation formed by the line connecting the radar transmitting station and the receiving station. The specific process is: the coordinates of the three points in the plane are known to be R k1 (x rk1 ,y rk1 ,z rk1 ), R k2 (x rk2 ,y rk2 ,z rk2 ), T n1 (x tn1 ,y tn1 ,z tn1 ), k1, k2, n1 are the available transmitting and receiving station numbers, and the plane equation is determined as: ax+by+cz+d=0 (1) where a = y rk1 (z rk2 -z tn1 ) + y rk2 (z tn1 -z rk1 ) + y tn1 (z rk1 -z rk2 ) b=z rk1 (x rk2 -x tn1 )+z rk2 (x tn1 -x rk1 )+z tn1 (x rk1 -x rk2 ); c=x rk1 (and rk2 -and tn1 )+x rk2 (and tn1 -and rk1 )+x tn1 (and rk1 -and rk2 ); d=-x rk1 (y rk2 z tn1 -y tn1 z rk2 )-x rk2 (y tn1 z rk1 -y rk1 z tn1 )-x tn1 (y rk1 z rk2 -y rk2 z rk1 ); Determine the equations of the x and y coordinate axes in the two-dimensional plane. The specific process is: Take R1 as the origin O and select receiving stations R1, R2…R K The straight line is taken as the x-axis, and two points (x rk1 ,y rk1 ,0)、(x rk2 ,y rk2 ,0) form the direction vector M1 of the straight line = (x rk2 -x rk1 ,y rk2 -y rk1 ,0); The equation of the line on the x-axis is: The y-axis passes through point R1(0,0,0) and also through point C(x C ,y C ,z C ), then the direction vector is M2=(x C ,y C ,z C ), the equation of the straight line on the y-axis is expressed as: Since the x-axis is perpendicular to the y-axis, the inner product of their direction vectors is zero: M1*M2=0. Since point C belongs to the plane formed by x and y, then: a×x C +b×y C +c×z C +d=0; As long as the condition that point C is on the y-axis is satisfied, its specific position is not important, and the x-axis coordinate of point C is 1, the problem is converted into solving a two-variable linear equation, and the solution is:

6. The method for estimating the three-dimensional spatial position of a forward scatter radar network target as claimed in claim 2, characterized in that: In the step 3, the three-dimensional coordinates of the transmitting station and the receiving station are converted into two-dimensional coordinates. The specific process is: the distance from each point on the plane to the x and y axes is calculated as the absolute value of the corresponding two-dimensional coordinates, and the quadrant of the point is determined according to the angle between the vector formed by each point and the origin and the x axis, so as to determine the coordinate sign; Taking the calculation of the x-axis coordinate as an example, the distance calculation process from a point to a straight line is as follows: The equation of the straight line along the y-axis is known to be: The foot coordinates of a point (x, y, z) outside the straight line on the straight line are D(x d ,y d ,z d ),set up Therefore Since the dot product of the direction vector of the perpendicular line and the direction vector of the y-axis is zero, we get: So solve for the perpendicular coordinates; The distance from a point to a line is: is the x-axis coordinate of the point (x, y, z) in the plane.

7. The method for estimating the three-dimensional spatial position of a forward scatter radar network target as claimed in claim 2, characterized in that: In step 4, the target parameter estimation equation is solved to obtain the target two-dimensional initial position coordinates. The specific process is: Based on the established parameter estimation equation, the P×6 matrix C is defined as: The estimation equation of the target motion parameters is given by: in, Right now x0=[(C T C) -1 C T F]1 (11) y0=[(C T C) -1 C T F]2 (12)。 8. The method for estimating the three-dimensional spatial position of a forward scatter radar network target as claimed in claim 2, characterized in that: In step 4, the estimated value of the target position in the two-dimensional plane is converted to the three-dimensional space. The specific process is: Calculate the direction angle of the x-axis and y-axis direction vectors in the two-dimensional plane, where the direction vector of the x-axis is M1=(x rk2 -x rk1 ,y rk2 -y rk1 ,0), the direction vector of the y-axis is M2=(x C ,y C ,z C ), so the direction angles are: The initial position of the target in three-dimensional space is (x'0, y'0, z'0). Based on the initial position of the target in the two-dimensional plane (x0, y0), we can get: Right now 9. A computer program storage medium for receiving user input, wherein the computer program stored in the computer program causes an electronic device to execute the forward scatter radar network target three-dimensional spatial position estimation method as claimed in any one of claims 1 to 8, comprising the following steps: First, a coordinate system is established to determine the positions of the transmitting station and the receiving station, the plane equation formed by the line connecting the transmitting station and the receiving station is solved, the x and y coordinate axes in the two-dimensional plane are determined, and the three-dimensional coordinates of the transmitter and the receiver are converted into two-dimensional coordinates in the same plane; Then, the parameter estimation equations are constructed based on the geometric structure of the forward scatter radar network and the equations are solved; Finally, the estimated value of the target position in the two-dimensional plane is converted into three-dimensional space to obtain the target position estimation result.

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