GNSS external radiation source radar moving target speed estimation method based on multi-satellite fusion

Abstract

The invention discloses a multi-satellite fusion-based GNSS (Global Navigation Satellite System) external radiation source radar moving target speed estimation method. The method comprises the following steps: calculating three-dimensional positions and speeds of a receiver and satellites based on direct wave data of at least three GNSS satellites received by a GNSS external radiation source radar receiver; based on moving target echo information received by a receiver detection channel, bistatic distance delay between each satellite and a moving target and target echo Doppler frequency observation values corresponding to the satellites are calculated respectively; calculating the three-dimensional position of the moving target based on the bistatic distance delay between each satellite and the moving target, the receiver and the three-dimensional position of each satellite; calculating the three-dimensional speed of the moving target based on the target echo Doppler frequency observation values corresponding to the satellites, the three-dimensional position of the moving target, and the three-dimensional positions and speeds of the satellites and the receiver; and performing error analysis on the three-dimensional speed of the moving target to obtain an error analysis result. According to the invention, the speed of the moving target in the three-dimensional space can be accurately estimated.

Description

Technical Field

[0001] The present invention relates to the field of radar detection technology, and in particular to a method for estimating the velocity of a moving target of a GNSS external radiation source radar based on multi-satellite fusion. Background Art

[0002] Exo-radiation radar is a dual / multi-base radar system that uses existing electromagnetic signals in space to detect targets by receiving and processing echo signals reflected by the target. The sources of opportunity for exo-radiation radar can be divided into ground-based radiation sources and space-based radiation sources. In recent years, with the rapid development of satellite technology, the number of space-based radiation sources has increased significantly, and space-based radiation signals usually have the advantages of wide coverage area and rich data sources, making exo-radiation radar technology based on space-based radiation sources gradually become a research hotspot.

[0003] In the related art, when using satellite GNSS external radiation source radar for moving target detection, single satellite data or azimuth angle measurement methods are mainly used for detection. However, the detection results obtained by the above methods not only have large distance positioning errors, but also because the azimuth resolution of the system is inversely proportional to the target distance, the detection accuracy will fluctuate with the change of the target position. Therefore, both methods cannot accurately capture the target speed information.

[0004] Based on this, there is an urgent need for a GNSS external radiation source radar moving target velocity estimation method based on multi-satellite fusion to solve the above problems. Summary of the invention

[0005] The present invention provides a moving target velocity estimation method based on multi-satellite fusion GNSS external radiation source radar, which can accurately estimate the velocity of the moving target in three-dimensional space. The technical solution is as follows:

[0006] In a first aspect, an embodiment of the present invention provides a method for estimating the velocity of a moving target using a GNSS external radiation source radar based on multi-satellite fusion, the method comprising:

[0007] Based on the direct wave data of at least three GNSS satellites received by the GNSS external radiation source radar receiver, the three-dimensional position and speed of the receiver and each satellite are calculated; each of the satellites can detect the moving target to be estimated;

[0008] Based on the moving target echo information received by the receiver detection channel, the bistatic distance delay between each satellite and the moving target and the target echo Doppler frequency observation value corresponding to each satellite are calculated respectively;

[0009] Calculating the three-dimensional position of the moving target based on the bistatic range delay between each satellite and the moving target, the three-dimensional position of the receiver and each satellite;

[0010] Calculating the three-dimensional velocity of the moving target based on the Doppler frequency observation value of the target echo corresponding to each satellite, the three-dimensional position of the moving target, and the three-dimensional position and velocity of each satellite and the receiver;

[0011] An error analysis is performed on the three-dimensional velocity of the moving target to obtain an error analysis result.

[0012] In a second aspect, an embodiment of the present invention further provides a GNSS external radiation source radar moving target velocity estimation device based on multi-satellite fusion, the device comprising:

[0013] A first calculation unit is used to calculate the three-dimensional position and velocity of the receiver and each satellite based on the direct wave data of at least three GNSS satellites received by the GNSS external radiation source radar receiver; each of the satellites can detect the moving target to be estimated;

[0014] A second calculation unit is used to calculate the bistatic distance delay between each satellite and the moving target, and the target echo Doppler frequency observation value corresponding to each satellite, based on the moving target echo information received by the receiver detection channel;

[0015] a third calculation unit, configured to calculate the three-dimensional position of the moving target based on the bistatic range delay between each satellite and the moving target, the three-dimensional position of the receiver and each satellite;

[0016] a fourth calculation unit, configured to calculate the three-dimensional velocity of the moving target based on the Doppler frequency observation value of the target echo corresponding to each satellite, the three-dimensional position of the moving target, and the three-dimensional position and velocity of each satellite and the receiver;

[0017] The analysis unit is used to perform error analysis on the three-dimensional velocity of the moving target to obtain an error analysis result.

[0018] In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method described in any embodiment of this specification is implemented.

[0019] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to execute the method described in any embodiment of this specification.

[0020] In a fifth aspect, an embodiment of the present invention further provides a computer program product, including a computer program, which implements the steps of the method described above when executed by a processor.

[0021] The embodiment of the present invention provides a method for estimating the velocity of a moving target using a GNSS external radiation source radar based on multi-satellite fusion. The method takes advantage of the rich GNSS satellite resources and uses a detection system consisting of at least three satellites and an external radiation source radar receiver to estimate the three-dimensional velocity of a moving target. First, the three-dimensional position and velocity of the receiver and each satellite are calculated based on the direct wave data received by the receiver. Then, based on the moving target echo information received by the receiver detection channel, the Doppler frequency measurement value and the three-dimensional position of the moving target and other information are calculated. Then, based on the target echo Doppler frequency observation value corresponding to each satellite, the three-dimensional position of the moving target, the three-dimensional position and velocity of each satellite and the receiver, the three-dimensional velocity of the moving target is calculated. Since the application utilizes data from multiple satellites, the information acquisition dimension of the system can be improved, thereby accurately estimating the velocity of the moving target in three-dimensional space. In addition, the present application also analyzes the factors affecting the accuracy of the three-dimensional velocity estimation of the moving target to obtain the error of the velocity estimation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a flow chart of a method for estimating the velocity of a moving target using a GNSS external radiation source radar based on multi-satellite fusion, provided by one embodiment of the present invention;

[0024] Figure 2 This is a structural diagram of a GNSS external radiation source radar moving target velocity estimation device based on multi-satellite fusion provided by an embodiment of the present invention;

[0025] Figure 3 is a hardware architecture diagram of a computer device provided by an embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of an external radiation source radar detection system provided by an embodiment of the present invention;

[0027] Figure 5 is a comparison curve between the target three-dimensional velocity estimation result and the theoretical value provided by an embodiment of the present invention;

[0028] Figure 6 A comparison curve of the theoretical standard deviation of the velocity error in three axes and the measured standard deviation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] The specific implementation of the above concept is described below.

[0031] Please refer to Figure 1 The embodiment of the present invention provides a method for estimating the velocity of a moving target using a GNSS external radiation source radar based on multi-satellite fusion, the method comprising:

[0032] Step 100, based on the direct wave data of at least three GNSS satellites received by the GNSS external radiation source radar receiver, the three-dimensional position and velocity of the receiver and each satellite are calculated; each satellite can detect the moving target to be estimated;

[0033] Step 102, based on the moving target echo information received by the receiver detection channel, respectively calculate the bistatic distance delay between each satellite and the moving target, and the target echo Doppler frequency observation value corresponding to each satellite;

[0034] Step 104, calculating the three-dimensional position of the moving target based on the bistatic range delay between each satellite and the moving target, the three-dimensional position of the receiver and each satellite;

[0035] Step 106, calculating the three-dimensional velocity of the moving target based on the Doppler frequency observation value of the target echo corresponding to each satellite, the three-dimensional position of the moving target, and the three-dimensional position and velocity of each satellite and the receiver;

[0036] Step 108, performing error analysis on the three-dimensional velocity of the moving target to obtain an error analysis result.

[0037] In this embodiment, taking advantage of the rich GNSS satellite resources, a detection system consisting of at least three satellites and an external radiation source radar receiver is used to estimate the three-dimensional velocity of a moving target. First, the three-dimensional position and velocity of the receiver and each satellite are calculated based on the direct wave data received by the receiver. Then, based on the moving target echo information received by the receiver detection channel, the Doppler frequency measurement value and the three-dimensional position of the moving target and other information are calculated. Then, based on the target echo Doppler frequency observation values ​​corresponding to each satellite, the three-dimensional position of the moving target, the three-dimensional position and velocity of each satellite and the receiver, the three-dimensional velocity of the moving target is calculated. Since the application utilizes data from multiple satellites, the information acquisition dimension of the system can be improved, thereby accurately estimating the velocity of the moving target in three-dimensional space. In addition, the present application also analyzes the factors affecting the accuracy of the three-dimensional velocity estimation of the moving target to obtain the error of the velocity estimation.

[0038] Described below Figure 1 How the various steps are performed.

[0039] First, with respect to step 100, step 102 and step 104:

[0040] Each GNSS satellite can detect the moving target to be estimated. At every moment, the receiver can receive the direct wave of the satellite and the echo information reflected by the moving target based on the direct channel and the detection channel. Then, the real-time three-dimensional position and velocity of the receiver and each satellite are calculated in real time based on the direct wave; based on the real-time echo information of the moving target, the dual-base distance delay between each satellite and the moving target, as well as the target echo Doppler frequency observation value corresponding to each satellite are calculated in real time.

[0041] In addition, after calculating the real-time three-dimensional position and velocity of the receiver and each satellite, the calculated coordinates need to be converted to the Earth-centered Earth-fixed coordinate system. At the same time, the acquired information is used to complete the time and frequency synchronization between the receiver and the satellite to achieve system preprocessing.

[0042] Finally, the real-time three-dimensional position of the moving target is calculated based on the calculated bistatic distance delay between each satellite and the moving target, the three-dimensional position of the receiver and each satellite.

[0043] It should be noted that the calculation method used in step 104 is an existing method for solving a nonlinear equation system, which will not be described in detail here.

[0044] Second, for step 106, based on the Doppler frequency observation value of the target echo corresponding to each satellite, the three-dimensional position of the moving target, and the three-dimensional position and velocity of each satellite and the receiver, the three-dimensional velocity of the moving target is calculated, including:

[0045] A1, based on the three-dimensional positions of each satellite, receiver and moving target, the unit vector from the moving target to each satellite and the unit vector from the moving target to the receiver are calculated respectively;

[0046] A2, based on the Doppler frequency observation value of the target echo corresponding to each satellite, the unit vector from the moving target to each satellite, the unit vector from the moving target to the receiver, the speed of the receiver and each satellite, the signal carrier wavelength and the Doppler frequency observation noise of the target echo corresponding to each satellite, construct an initial set of equations containing the three-dimensional velocity of the moving target;

[0047] A3, solve the initial set of equations to obtain the three-dimensional velocity of the moving target.

[0048] like Figure 4 FIG. 1 is a schematic diagram of a detection system composed of satellites, radar receivers and moving targets. The following uses this diagram as an example to describe the calculation process of steps A1 to A3 in detail.

[0049] First, for step A1, the real-time positions of each satellite, radar receiver and moving target can be calculated through steps 100 to 104. Under the premise that the positions of each device are known, the method for calculating the unit vector from the moving target to each satellite and the unit vector from the moving target to the receiver is an existing method and will not be repeated here.

[0050] Then, for step A2, the calculation formula of the Doppler frequency observation value is first listed, that is, the Doppler frequency observation value of the GNSS signal reflected by the target in the detection channel is equal to the ratio of the derivative of the dual-base range delay between the satellite and the moving target to the time and the carrier wavelength:

[0051]

[0052] In the formula, f d (t) represents the Doppler frequency observation value of the target echo from the satellite at time t; R(t) represents the dual-base distance delay between the satellite and the moving target at time t.

[0053] Since there are multiple GNSS satellites in this application, the initial set of equations related to the target Doppler frequency observation value can be obtained according to formula (1). The expression of the initial set of equations is as follows:

[0054]

[0055] In the formula, f di represents the Doppler frequency observation value of the target echo corresponding to the i-th satellite, i = 1, 2...m, m is the number of satellites, m is not less than 3; λ represents the signal carrier wavelength; v si represents the velocity vector of the i-th satellite; v r represents the velocity vector of the receiver; utsi The unit vector representing the direction from the moving target to the i-th satellite; u tr The unit vector representing the direction from the moving target to the receiver; v t Represents the velocity vector of the moving target; n fi represents the target echo Doppler frequency observation noise corresponding to the i-th satellite.

[0056] In the above equations, removing the observation noise n fi In addition, the equations only contain the three-dimensional velocity coordinates v of the target. t =[v tx ,v ty ,v tz ]These three unknown variables. Observation noise n fi It can be determined according to the actual detection scene. Therefore, it is only necessary to solve the above initial set of equations to obtain the three-dimensional velocity of the moving target.

[0057] Finally, for step A3, it includes:

[0058] B1, transform and rearrange the initial equations to obtain the apparent Doppler frequency observation value equations;

[0059] B2, based on the relationship between the dual-base range delay between each satellite and the moving target and the unit vector from the moving target to each satellite and the unit vector from the moving target to the receiver, the apparent Doppler frequency observation value equation group is simplified to obtain a simplified apparent Doppler frequency observation value equation group;

[0060] B3, based on the vector definition, the simplified apparent Doppler frequency observation value equation group is converted into an apparent Doppler frequency observation value observation matrix;

[0061] B4, based on the least squares method, the apparent Doppler frequency observation value observation matrix is ​​solved to obtain the three-dimensional velocity of the moving target.

[0062] First, for step B1, based on the acquired motion information of each GNSS satellite and receiver, the influence of the relative motion of each GNSS satellite and receiver on the Doppler frequency observation value is first eliminated. At this time, the residual Doppler frequency is mainly determined by the target motion and observation noise. The known satellite velocity and receiver velocity terms in equation (2) are sorted and moved to the left side of the equation, and the following form of apparent Doppler frequency observation value equation group is obtained:

[0063]

[0064] Secondly, for step B2, define the apparent Doppler frequency observation value f corresponding to the i-th satellite tdi for:

[0065]

[0066] Define the bistatic distance gradient vector between the i-th satellite and the moving target as u i :

[0067] u i =u tsi +u tr

[0068] Then the expression of the apparent Doppler frequency observation value equation group simplified by formula (3) is:

[0069]

[0070] It can be seen from formula (4) that the apparent Doppler frequency observation value is completely determined by the projection of the target velocity on the dual-base range gradient vector and the Doppler frequency observation noise of the system.

[0071] Then, for step B3, through vector definition, the matrix f composed of the apparent Doppler frequency observation values ​​corresponding to each satellite is obtained respectively td , the matrix U composed of the dual-base range gradient vectors between each satellite and the moving target and the matrix n composed of the target echo Doppler frequency observation noise corresponding to each satellite f The definitions of each matrix are as follows:

[0072] in,

[0073] In the formula, f tdi represents the apparent Doppler frequency observation value corresponding to the i-th satellite; u i represents the bistatic range gradient vector between the ith satellite and the moving target, pointing to the bisector of the bistatic angle β, as Figure 4 As shown, each GNSS satellite has a corresponding dual-base range gradient vector, and the corresponding dual-base range change speed has a maximum value when the target moves along this direction.

[0074] Through the above definition, the expression of the apparent Doppler frequency observation value measurement matrix is ​​obtained as follows:

[0075]

[0076] Finally, for step B4, equation (5) is a linear state observation equation, which does not require linearization and Newton iteration. Therefore, it can be solved by the least squares method to obtain the three-dimensional velocity of the moving target. The result is as follows:

[0077] v t =λ(U T U) -1 U T ftd .

[0078] Through the above formula, the three-dimensional velocity parameters of the target can be estimated.

[0079] Finally, step 108 includes:

[0080] Predefine the velocity error transfer matrix;

[0081] Based on the velocity error transfer matrix, the error transfer relationship between the target 3D velocity estimation error and the Doppler frequency observation noise is derived, and the variance of the target 3D velocity estimation error is obtained.

[0082] Based on the relationship between the velocity error transfer matrix and the constant velocity error coefficient, the standard deviation of the target three-dimensional velocity estimation error is calculated.

[0083] In this step, the target 3D velocity estimation error caused by the observation noise nfi is defined as δv t =[δv tx ,δv ty ,δv tz ] T When the observation noise is smaller than the apparent Doppler frequency observation vector, it can be derived that:

[0084] δv t =λ(U T U) -1 U T n f

[0085] Target 3D velocity estimation error δv t and the apparent Doppler frequency observation vector f td is independent of, but only affected by the observed noise vector n f The covariance matrix of the target three-dimensional velocity estimation error can be derived as follows:

[0086]

[0087] in, C nf is the Doppler frequency observation noise vector n f The covariance matrix of .

[0088] Assume that the apparent Doppler frequency observation noises corresponding to different GNSS satellites are independent of each other, and the apparent Doppler frequency observation noises corresponding to these satellites have consistent power, that is, Here, I represents an m×m-order identity matrix. Substituting into equation (6), the unit matrix I can be eliminated, and the expression of the variance of the target 3D velocity estimation error is obtained as follows:

[0089]

[0090] The velocity error transfer matrix is ​​defined as: Since U points to the bisector of the bistatic angle β, S reflects the geometric configuration of the system. Variance of Doppler frequency observation error It is scaled by the error transfer matrix S and converted into the variance of the target three-dimensional velocity estimation error.

[0091] It can be seen from formula (7) that the estimation accuracy of the target's three-dimensional velocity is mainly determined by the measurement accuracy of the Doppler frequency and the geometric relationship between the GNSS satellite, the receiver, and the target at the moment of observation.

[0092] The root of the covariance matrix obtained by formula (7) gives the standard deviation σ of the target 3D velocity estimation error: vt , the expression of standard deviation is:

[0093]

[0094] in,

[0095] In the formula, δv t represents the target 3D velocity estimation error; var(δv t ) and σ vt Respectively represent δv t The variance and standard deviation of f represents the standard deviation of the Doppler frequency observation error of the system; S represents the velocity error transfer matrix; U represents the matrix composed of the dual-base range gradient vectors between each satellite and the moving target; u i represents the bistatic range gradient vector between the ith satellite and the moving target; κ vt represents the constant speed error coefficient; σ vx , σ vy , σ vz Represents the standard deviation of the velocity estimation error along the x, y, and z axes respectively.

[0096] From formula (8), we can see that the standard deviation σ of the target 3D velocity estimation error is vt Equal to the standard deviation of the system Doppler frequency observation error σ f Scaling κ vt The result after the speed error coefficient is related to S, which is mainly determined by the geometric configuration of the GNSS external emitter radar system, and characterizes the scaling characteristics of the GNSS external emitter radar system to the Doppler frequency observation noise. Under certain Doppler frequency observation error conditions, a larger speed error coefficient usually corresponds to a poorer target velocity estimation accuracy.

[0097] In order to prove the effectiveness of the method of this application, the inventor built the following Figure 4 The simulation system shown utilizes simulation methods to simulate the actual detection system and performs full-link simulation processing and analysis.

[0098] In the simulation system, the target is set as a moving aircraft, and a total of 4 GNSS satellites are used. The settings of the satellite parameters and detection parameters are shown in Table 1. The three-dimensional position and velocity information of each satellite and receiver in the Earth-centered Earth-fixed coordinate system are shown in Table 2.

[0099] Table 1 Detection system simulation parameters

[0100] parameter value satellite GPS PRN1 L1 signal Signal bandwidth 1.023MHz Sampling rate 4MHz Equivalent pulse repetition frequency 1000Hz Simulation duration 60s

[0101] Table 2 Position and velocity of the receiver and satellites in the Earth-centered Earth-fixed coordinate system

[0102]

[0103] In the simulation program, the parameters of the target in the station center coordinate system (with the receiver as the origin) and the earth center earth fixed coordinate system (with the center of the earth as the origin) are set as shown in Table 3, and the parameters are used as the true values ​​of the moving target for comparison with the estimated results calculated by the method of the present application.

[0104] Table 3 Target position and speed settings in different coordinate systems

[0105]

[0106] In addition, in the simulation, the standard deviation of the Doppler frequency observation noise is set to 20 Hz, and a random error is added to each Doppler measurement value.

[0107] Based on the above parameters, the position and velocity of the set moving target are continuously estimated within a continuous observation time of 60 seconds, and the estimated results are compared with the real values ​​set in the simulation, and the errors are analyzed. In the simulation process, the target three-dimensional velocity estimation method proposed in the above embodiment is first used to estimate the parameters. The target three-dimensional velocity estimation results in the earth-centered earth-fixed coordinate system and the comparison curve with the theoretical value are shown in Figure 2. Figure 5 As shown in the figure, it can be seen that the estimated results of the target speed along the three coordinate axes are in good agreement with the true values, which verifies the effectiveness of the target three-dimensional speed estimation method based on multi-satellite fusion proposed in this application. Then, the error of the calculated speed is estimated, and the speed estimation error along the x, y, and z axes is as follows: Figure 6 As shown in the figure, according to the parameters set in the simulation, the theoretical standard deviations of the velocity estimation errors along the x, y, and z axes in the Earth-centered Earth-fixed coordinate system are σ vx =5.2m / s,σ vy=3.6m / s,σ vz =4.8m / s, the standard deviations of the velocity estimation errors along the x, y, and z axes obtained by actual measurement are σ vx =5.2m / s,σ vy =3.6m / s,σ vz =4.8m / s. It can be seen that the target speed estimated by the method of the present application is of high accuracy.

[0108] In summary, the measured values ​​are in good agreement with the theoretical values, which verifies the correctness of the theoretical analysis of the target three-dimensional velocity estimation error in the Earth-centered Earth-fixed coordinate system.

[0109] like Figure 2 , Figure 3 As shown, an embodiment of the present invention provides a GNSS external radiation source radar moving target velocity estimation device based on multi-satellite fusion. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, Figure 2 FIG. 1 is a hardware architecture diagram of a computing device where a GNSS external radiation source radar moving target velocity estimation device based on multi-satellite fusion provided by an embodiment of the present invention is located. Figure 2 In addition to the processor, memory, network interface, and non-volatile memory shown in the figure, the computing device in which the device is located in the embodiment may also generally include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking software implementation as an example, Figure 3 As shown, as a device in a logical sense, the CPU of the computing device in which it is located reads the corresponding computer program in the non-volatile memory into the internal memory and runs it.

[0110] Please refer to Figure 3 The embodiment of the present invention provides a GNSS external radiation source radar moving target velocity estimation device based on multi-satellite fusion, the device comprising:

[0111] The first calculation unit 300 is used to calculate the three-dimensional position and velocity of the receiver and each satellite based on the direct wave data of at least three GNSS satellites received by the GNSS external radiation source radar receiver; each satellite can detect the moving target to be estimated;

[0112] The second calculation unit 302 is used to calculate the bistatic distance delay between each satellite and the moving target, and the target echo Doppler frequency observation value corresponding to each satellite, based on the moving target echo information received by the receiver detection channel;

[0113] A third calculation unit 304 is used to calculate the three-dimensional position of the moving target based on the bistatic range delay between each satellite and the moving target, the three-dimensional position of the receiver and each satellite;

[0114] The fourth calculation unit 306 is used to calculate the three-dimensional velocity of the moving target based on the Doppler frequency observation value of the target echo corresponding to each satellite, the three-dimensional position of the moving target, and the three-dimensional position and velocity of each satellite and the receiver;

[0115] The analysis unit 308 is used to perform error analysis on the three-dimensional velocity of the moving target to obtain an error analysis result.

[0116] In some implementations, the fourth computing unit 306 is configured to perform the following operations:

[0117] Based on the three-dimensional positions of each satellite, the receiver and the moving target, the unit vectors from the moving target to each satellite and the unit vectors from the moving target to the receiver are calculated respectively;

[0118] Based on the Doppler frequency observation value of the target echo corresponding to each satellite, the unit vector from the moving target to each satellite, the unit vector from the moving target to the receiver, the speed of the receiver and each satellite, the signal carrier wavelength and the Doppler frequency observation noise of the target echo corresponding to each satellite, an initial set of equations including the three-dimensional velocity of the moving target is constructed;

[0119] The initial set of equations is solved to obtain the three-dimensional velocity of the moving target.

[0120] In some embodiments, the initial set of equations is expressed as follows:

[0121]

[0122] In the formula, f di represents the Doppler frequency observation value of the target echo corresponding to the i-th satellite, i = 1, 2...m, m is the number of satellites, m is not less than 3; λ represents the signal carrier wavelength; v si represents the velocity vector of the i-th satellite; v r represents the velocity vector of the receiver; u tsi The unit vector representing the direction from the moving target to the i-th satellite; u tr The unit vector representing the direction from the moving target to the receiver; v t Represents the velocity vector of the moving target; n fi represents the target echo Doppler frequency observation noise corresponding to the i-th satellite.

[0123] In some implementations, the fourth calculation unit 306 is used to perform the following operations when solving the initial set of equations to obtain the three-dimensional velocity of the moving target:

[0124] The initial set of equations is deformed and rearranged to obtain the set of equations for apparent Doppler frequency observation values;

[0125] Based on the relationship between the bistatic distance delay between each satellite and the moving target and the unit vector from the moving target to each satellite and the unit vector from the moving target to the receiver, the apparent Doppler frequency observation value equation group is simplified to obtain the simplified apparent Doppler frequency observation value equation group;

[0126] Based on the vector definition, the simplified apparent Doppler frequency observation value equation group is transformed into an apparent Doppler frequency observation value observation matrix;

[0127] The apparent Doppler frequency observation matrix is ​​solved based on the least squares method to obtain the three-dimensional velocity of the moving target.

[0128] In some implementations, the analysis unit 308 is configured to perform the following operations:

[0129] Predefine the velocity error transfer matrix;

[0130] Based on the velocity error transfer matrix, the error transfer relationship between the target 3D velocity estimation error and the Doppler frequency observation noise is derived, and the variance of the target 3D velocity estimation error is obtained.

[0131] Based on the relationship between the velocity error transfer matrix and the constant velocity error coefficient, the standard deviation of the target three-dimensional velocity estimation error is calculated.

[0132] In some implementations, the variance of the target 3D velocity estimation error is expressed as:

[0133]

[0134] The expression of the standard deviation of the target three-dimensional velocity estimation error is:

[0135] σ vt =κ vt σ f ,

[0136] In the formula, δv t represents the target 3D velocity estimation error; var(δv t ) and σ vt Respectively represent δv t The variance and standard deviation of f represents the standard deviation of the Doppler frequency observation error of the system; S represents the velocity error transfer matrix; U represents the matrix composed of the dual-base range gradient vectors between each satellite and the moving target; u i represents the bistatic range gradient vector between the ith satellite and the moving target; κ vt Indicates the constant speed error coefficient.

[0137] It should be noted that the GNSS external radiation source radar moving target velocity estimation device based on multi-star fusion provided in the above embodiment is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the GNSS external radiation source radar moving target velocity estimation device based on multi-star fusion provided in the above embodiment and the GNSS external radiation source radar moving target velocity estimation method embodiment based on multi-star fusion belong to the same concept. The specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0138] The embodiment of the present application also provides a computer device, please refer to Figure 3 The computer device includes a processor and a memory, wherein at least one instruction, at least one program, a code set or an instruction set is stored in the memory, and the at least one instruction, at least one program, a code set or an instruction set is loaded and executed by the processor to implement the GNSS external radiation source radar moving target velocity estimation method based on multi-star fusion provided by the above-mentioned method embodiments.

[0139] An embodiment of the present application also provides a computer-readable storage medium, on which is stored at least one instruction, at least one program, code set or instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by a processor to implement the GNSS external radiation source radar moving target velocity estimation method based on multi-star fusion provided in the above-mentioned method embodiments.

[0140] An embodiment of the present application also provides a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium, and the processor executes the computer program, so that the computer device executes the GNSS external radiation source radar moving target velocity estimation method based on multi-star fusion as described in any of the above embodiments.

[0141] For the convenience of description, the above system or device is described by dividing it into various modules or units according to its functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0142] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0143] Finally, it should be noted that, in this article, relational terms such as first, second, third and fourth are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0144] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for estimating the velocity of a moving target based on a GNSS external radiation source radar using multi-satellite fusion, characterized in that: The method comprises: Based on the direct wave data of at least three GNSS satellites received by the GNSS external radiation source radar receiver, the three-dimensional position and speed of the receiver and each satellite are calculated; each of the satellites can detect the moving target to be estimated; Based on the moving target echo information received by the receiver detection channel, the bistatic distance delay between each satellite and the moving target and the target echo Doppler frequency observation value corresponding to each satellite are calculated respectively; Calculating the three-dimensional position of the moving target based on the bistatic range delay between each satellite and the moving target, the three-dimensional position of the receiver and each satellite; Calculating the three-dimensional velocity of the moving target based on the Doppler frequency observation value of the target echo corresponding to each satellite, the three-dimensional position of the moving target, and the three-dimensional position and velocity of each satellite and the receiver; An error analysis is performed on the three-dimensional velocity of the moving target to obtain an error analysis result.

2. The method according to claim 1, characterized in that The method of calculating the three-dimensional velocity of the moving target based on the Doppler frequency observation value of the target echo corresponding to each satellite, the three-dimensional position of the moving target, and the three-dimensional position and velocity of each satellite and the receiver includes: Based on the three-dimensional positions of each satellite, the receiver and the moving target, respectively calculating the unit vector from the moving target to each satellite and the unit vector from the moving target to the receiver; Based on the target echo Doppler frequency observation value corresponding to each satellite, the unit vector from the moving target to each satellite, the unit vector from the moving target to the receiver, the speed of the receiver and each satellite, the signal carrier wavelength and the target echo Doppler frequency observation noise corresponding to each satellite, construct an initial equation group containing the three-dimensional velocity of the moving target; The initial set of equations is solved to obtain the three-dimensional velocity of the moving target.

3. The method according to claim 2, characterized in that The expression of the initial set of equations is as follows: In the formula, f di represents the Doppler frequency observation value of the target echo corresponding to the i-th satellite, i = 1, 2...m, m is the number of satellites, m is not less than 3; λ represents the signal carrier wavelength; v si represents the velocity vector of the i-th satellite; v r represents the velocity vector of the receiver; u tsi The unit vector representing the direction from the moving target to the i-th satellite; u tr The unit vector representing the direction from the moving target to the receiver; v t Represents the velocity vector of the moving target; n fi represents the target echo Doppler frequency observation noise corresponding to the i-th satellite.

4. The method according to claim 3, characterized in that The step of solving the initial set of equations to obtain the three-dimensional velocity of the moving target includes: The initial set of equations is deformed and rearranged to obtain an apparent Doppler frequency observation value set of equations; Based on the relationship between the bistatic distance delay between each satellite and the moving target and the unit vector from the moving target to each satellite and the unit vector from the moving target to the receiver, the apparent Doppler frequency observation value equation group is simplified to obtain a simplified apparent Doppler frequency observation value equation group; Based on the vector definition, the simplified apparent Doppler frequency observation value equation group is transformed into an apparent Doppler frequency observation value observation matrix; The apparent Doppler frequency observation value observation matrix is ​​solved based on the least square method to obtain the three-dimensional velocity of the moving target.

5. The method according to claim 3, characterized in that: Performing error analysis on the three-dimensional velocity of the moving target to obtain error analysis results, including: Predefine the velocity error transfer matrix; Based on the velocity error transfer matrix, an error transfer relationship between a target three-dimensional velocity estimation error and Doppler frequency observation noise is derived to obtain a variance of the target three-dimensional velocity estimation error; Based on the relationship between the velocity error transfer matrix and the constant velocity error coefficient, the standard deviation of the target three-dimensional velocity estimation error is calculated.

6. The method according to claim 5, characterized in that The expression of the variance of the target three-dimensional velocity estimation error is: The expression of the standard deviation of the target three-dimensional velocity estimation error is: s vt =k vt s f , In the formula, δv t represents the target 3D velocity estimation error; var(δv t ) and σ vt Respectively represent δv t The variance and standard deviation of f represents the standard deviation of the Doppler frequency observation error of the system; S represents the velocity error transfer matrix; U represents the matrix composed of the dual-base range gradient vectors between each satellite and the moving target; u i represents the bistatic range gradient vector between the ith satellite and the moving target; κ vt Indicates the constant speed error coefficient.

7. A GNSS external radiation source radar moving target velocity estimation device based on multi-satellite fusion, characterized in that: The device comprises: A first calculation unit is used to calculate the three-dimensional position and velocity of the receiver and each satellite based on the direct wave data of at least three GNSS satellites received by the GNSS external radiation source radar receiver; each of the satellites can detect the moving target to be estimated; A second calculation unit is used to calculate the bistatic distance delay between each satellite and the moving target, and the target echo Doppler frequency observation value corresponding to each satellite, based on the moving target echo information received by the receiver detection channel; a third calculation unit, configured to calculate the three-dimensional position of the moving target based on the bistatic range delay between each satellite and the moving target, the three-dimensional position of the receiver and each satellite; a fourth calculation unit, configured to calculate the three-dimensional velocity of the moving target based on the Doppler frequency observation value of the target echo corresponding to each satellite, the three-dimensional position of the moving target, and the three-dimensional position and velocity of each satellite and the receiver; The analysis unit is used to perform error analysis on the three-dimensional velocity of the moving target to obtain an error analysis result.

8. A computing device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises a computer program, wherein when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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