A multi-target radar return simulation method, system, device, and medium

Abstract

The application discloses a multi-target radar echo simulation method, system, device and medium, relates to the technical field of radar simulation, and is used for solving the technical problems that the prior art is difficult to support complex trajectory intersection scenes, Doppler ambiguity and the like. The method comprises the following steps: calculating initial Doppler shift values of targets according to configuration parameters of the targets; wherein each target is allocated with an independent Doppler calculation channel; performing separation processing on a plurality of targets for which trajectory intersection is detected; performing Doppler ambiguity compensation and coupling correction on the targets to obtain corrected Doppler shift values of the targets; and synthesizing multi-target echo signals according to the corrected Doppler shift values of the targets and an RCS fluctuation model. Therefore, the application can effectively support complex trajectory intersection scenes, reduce Doppler ambiguity and the like through an independent Doppler channel, trajectory intersection detection, Doppler ambiguity compensation, coupling correction and the like.

Description

Technical Field

[0001] This application relates to the field of radar simulation technology, and provides a method, system, device and medium for simulating multi-target radar echoes. Background Technology

[0002] As is well known, radar target simulators are important tools for the research, development, testing and evaluation of radar systems. By simulating target echo signals, they enable radar systems to complete various functional tests in a laboratory environment without the need for actual flight tests, thereby significantly reducing testing costs and risks.

[0003] However, with the rapid development of radar technology, the requirements for radar target simulators are becoming increasingly demanding. Modern radar systems need to be able to simulate multiple man-made targets, complex trajectories, and high dynamic characteristics, requiring target simulators to possess multi-target simulation capabilities. However, existing multi-target radar echo simulation methods have the following shortcomings: First, traditional multi-target Doppler control schemes employ a centralized processing architecture, which allocates an independent Doppler channel to each target and generates multi-target echoes through time-division multiplexing or frequency-division multiplexing. This architecture works well when the number of targets is small, but as the number of targets increases, the processor's computational load rises sharply, making it difficult to meet real-time requirements. Furthermore, the centralized architecture has poor scalability; increasing the number of targets requires significant hardware modifications.

[0004] Second, existing solutions struggle to support complex trajectory intersection scenarios. In practical applications, multiple targets may exhibit complex motion trajectories such as intersection, divergence, and convergence. When two targets are spatially close or intersect, their Doppler characteristics are prone to aliasing and interference. Traditional solutions typically employ simple temporal domain separation methods, which cannot accurately simulate the Doppler variation trends when targets intersect, leading to significant discrepancies between simulation results and real-world scenarios.

[0005] Third, high-speed targets suffer from Doppler blurring. When a target's speed is high, its Doppler frequency shift may exceed half of the pulse repetition frequency (PRF), resulting in speed blurring. Current technologies for processing high-speed targets primarily rely on sampling and relaying by the digital radio frequency memory (DRFM) in hardware, which cannot accurately reconstruct the Doppler characteristics of high-speed moving targets, leading to Doppler blurring.

[0006] Fourth, the coupling effect between Doppler and range has not been fully considered. In scenarios with a large dynamic range, significant changes in target range can lead to changes in signal propagation delay, thus affecting the accuracy of Doppler parameter calculation. Existing solutions typically treat Doppler and range as independent parameters, neglecting the coupling relationship between them.

[0007] Fifth, the radar cross section (RCS) fluctuation characteristics of different targets are difficult to control independently. In real-world environments, the RCS characteristics of different targets vary greatly. For example, ship targets exhibit slow RCS fluctuations, while rotorcraft targets experience periodic obstruction effects. Existing solutions typically employ a uniform RCS model, making it difficult to independently control the RCS fluctuation characteristics of different targets. Summary of the Invention

[0008] This application provides a method, system, device, and medium for simulating multi-target radar echoes, which solves the technical problems in the prior art, such as difficulty in supporting complex trajectory intersection scenarios and Doppler blurring.

[0009] On the one hand, a method for simulating multi-target radar echoes is provided, the method comprising: Parameters are configured for multiple targets to obtain configuration parameters for each target; wherein, the configuration parameters include motion parameters and radar cross section (RCS) fluctuation model parameters; Based on the configuration parameters of each target, the initial Doppler frequency shift value of each target is calculated; each target is assigned an independent Doppler calculation channel. Separate multiple targets whose trajectories intersect; Based on the initial Doppler frequency shift values ​​of each target, Doppler ambiguity compensation is performed on each target to obtain the true Doppler frequency shift values ​​of each target; Based on the distance change rate of each target, the true Doppler frequency shift value of each target is coupled and corrected to obtain the corrected Doppler frequency shift value of each target. Based on the corrected Doppler frequency shift values ​​and RCS wave model of each target, multi-target echo signals are synthesized.

[0010] Optionally, the step of calculating the initial Doppler frequency shift value of each target based on the configuration parameters of each target includes: Each target is assigned an independent Doppler calculation channel; these Doppler calculation channels operate in parallel. Calculate the radial velocity of each target based on its configuration parameters; Based on the radial velocity of each target, the initial Doppler shift value of each target is calculated.

[0011] Optionally, the step of separating multiple targets that have been detected to have intersected trajectories includes: For any two targets, predict the positions of the two targets at the next moment based on the motion parameters of the two targets at the current moment; Determine whether the predicted distance between the positions of any two targets at the next moment is less than a distance threshold; If it is determined that the predicted distance between the positions of any two targets in the next moment is less than the distance threshold, then it is determined that the trajectories of any two targets intersect. A time-domain separation strategy is adopted to separate any two targets.

[0012] Optionally, the step of performing Doppler blur compensation on each target based on the initial Doppler frequency shift value of each target to obtain the true Doppler frequency shift value of each target includes: The Doppler unambiguity range is determined based on the set pulse repetition frequency (PRF). For any given target, determine whether the initial Doppler frequency shift value of the target is within the range of Doppler ambiguity-free conditions; If it is determined that the initial Doppler frequency shift value of any target is not within the Doppler unambiguous range, then the initial Doppler frequency shift value of any target is subjected to modulo PRF operation to obtain the ambiguous Doppler frequency shift value of any target. The final fuzzy factor of any target is determined by adopting a preset joint decision criterion; wherein the preset joint decision criterion includes the target maximum acceleration constraint and the Doppler rate of change variance minimum criterion. Calculate the true Doppler shift value of any target based on its final blur factor and blurry Doppler shift value.

[0013] Optionally, the step of determining the final fuzziness factor of any one target using a preset joint decision criterion includes: Based on the measured Doppler frequency shift values ​​of M consecutive frames of any target, calculate the true Doppler sequence corresponding to each candidate blur factor of any target; where M is a positive integer not less than 4; Based on the target maximum acceleration constraint and the real Doppler sequence corresponding to each candidate fuzziness factor, the multiple candidate fuzziness factors are subjected to a first-level screening to obtain multiple first-level fuzziness factors; Based on the minimum variance criterion of Doppler rate of change and the real Doppler sequence corresponding to each first-level ambiguity factor, a second-level screening is performed on the multiple first-level ambiguity factors to obtain the final ambiguity factor of any target.

[0014] Optionally, the step of performing coupled correction on the true Doppler frequency shift value of each target based on the distance change rate of each target to obtain the corrected Doppler frequency shift value of each target includes: Calculate the rate of change of distance for each target based on the distance it has traveled. The coupling coefficient of each target is determined based on the rate of change of distance to each target. Based on the distance change rate and coupling coefficient of each target, the true Doppler frequency shift value of each target is coupled and corrected to obtain the corrected Doppler frequency shift value of each target.

[0015] Optionally, the step of obtaining the multi-target synthetic echo signal based on the corrected Doppler frequency shift value and RCS wave model of each target includes: Based on the RCS fluctuation model parameters of each target, an independent RCS fluctuation model is configured for each target. Based on the RCS fluctuation model of each target, calculate the RCS parameters of each target respectively; The corrected Doppler frequency shift, RCS parameter and initial phase of each target are subjected to complex exponential modulation to generate the baseband echo signal of each target; The baseband echo signals of each target are summed by power weighting to obtain the multi-target composite echo signal.

[0016] On the one hand, a multi-target radar echo simulation system is provided, the system comprising: The parameter configuration unit is used to configure parameters for multiple targets and obtain configuration parameters for each target; wherein, the configuration parameters include motion parameters and radar cross section (RCS) fluctuation model parameters; The Doppler calculation unit is used to calculate the initial Doppler frequency shift value of each target according to the configuration parameters of each target; wherein, each target is assigned an independent Doppler calculation channel; The trajectory intersection detection unit is used to separate multiple targets that are detected to have intersecting trajectories; The fuzzy compensation unit is used to perform Doppler fuzzy compensation on each target based on the initial Doppler frequency shift value of each target, so as to obtain the true Doppler frequency shift value of each target. The coupling correction unit is used to perform coupling correction on the true Doppler frequency shift value of each target according to the distance change rate of each target, so as to obtain the corrected Doppler frequency shift value of each target. The echo synthesis unit is used to synthesize multi-target echo signals based on the corrected Doppler frequency shift value and RCS wave model of each target.

[0017] On one hand, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the methods described above.

[0018] On the one hand, a storage medium is provided that stores computer program instructions thereon, which, when executed by a processor, implement any of the methods described above.

[0019] Compared with the prior art, the beneficial effects of this application are as follows: In this application, when performing multi-target radar echo simulation, firstly, parameters can be configured for multiple targets to obtain configuration parameters for each target; wherein, the configuration parameters include motion parameters and radar cross section (RCS) fluctuation model parameters; then, the initial Doppler frequency shift value of each target can be calculated according to the configuration parameters of each target; wherein, each target is assigned an independent Doppler calculation channel; next, multiple targets that are detected to have intersecting trajectories can be separated; then, Doppler ambiguity compensation can be performed on each target according to the initial Doppler frequency shift value of each target to obtain the true Doppler frequency shift value of each target; next, the true Doppler frequency shift value of each target can be coupled and corrected according to the range change rate of each target to obtain the corrected Doppler frequency shift value of each target; finally, the multi-target echo signal can be synthesized according to the corrected Doppler frequency shift value of each target and the RCS fluctuation model.

[0020] Based on this, in this application, since each target is assigned an independent Doppler calculation channel, this application has high scalability compared to the prior art. In addition, since complex trajectory intersection detection and separation processing is performed on each target, this application can accurately simulate complex scenarios such as multi-target intersection, lane splitting, and convergence, avoiding Doppler aliasing, compared to the prior art. Furthermore, since Doppler blur compensation is performed on each target, this application can effectively solve the Doppler blur problem of high-speed targets, expanding the speed simulation range of the system, compared to the prior art. In addition, since the true Doppler frequency shift value of each target is corrected, this application can improve the Doppler calculation accuracy in large dynamic range scenarios through correction, compared to the prior art. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of this application; Figure 2 A flowchart illustrating a multi-target radar echo simulation method provided in this application embodiment; Figure 3 This is a schematic diagram of a multi-target radar echo simulation system provided in an embodiment of this application.

[0023] The diagram is labeled as follows: 10-Multi-target radar echo simulation device, 101-Processor, 102-Memory, 103-I / O interface, 104-Database, 30-Multi-target radar echo simulation system, 301-Parameter configuration unit, 302-Doppler calculation unit, 303-Trajectory crossover detection unit, 304-Fuzzy compensation unit, 305-Coupling correction unit, 306-Echo synthesis unit. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0025] As is well known, radar target simulators are important tools for the research, development, testing and evaluation of radar systems. By simulating target echo signals, they enable radar systems to complete various functional tests in a laboratory environment without the need for actual flight tests, thereby significantly reducing testing costs and risks.

[0026] However, with the rapid development of radar technology, the requirements for radar target simulators are becoming increasingly demanding. Modern radar systems need to be able to simulate multiple man-made targets, complex trajectories, and high dynamic characteristics, requiring target simulators to possess multi-target simulation capabilities. However, existing multi-target radar echo simulation methods have the following shortcomings: First, traditional multi-target Doppler control schemes employ a centralized processing architecture, which allocates an independent Doppler channel to each target and generates multi-target echoes through time-division multiplexing or frequency-division multiplexing. This architecture works well when the number of targets is small, but as the number of targets increases, the processor's computational load rises sharply, making it difficult to meet real-time requirements. Furthermore, the centralized architecture has poor scalability; increasing the number of targets requires significant hardware modifications.

[0027] Second, existing solutions struggle to support complex trajectory intersection scenarios. In practical applications, multiple targets may exhibit complex motion trajectories such as intersection, divergence, and convergence. When two targets are spatially close or intersect, their Doppler characteristics are prone to aliasing and interference. Traditional solutions typically employ simple temporal domain separation methods, which cannot accurately simulate the Doppler variation trends when targets intersect, leading to significant discrepancies between simulation results and real-world scenarios.

[0028] Third, high-speed targets suffer from Doppler blurring. When a target's speed is high, its Doppler frequency shift may exceed half of the pulse repetition frequency (PRF), resulting in speed blurring. Current technologies for processing high-speed targets primarily rely on sampling and relaying by the digital radio frequency memory (DRFM) in hardware, which cannot accurately reconstruct the Doppler characteristics of high-speed moving targets, leading to Doppler blurring.

[0029] Fourth, the coupling effect between Doppler and range has not been fully considered. In scenarios with a large dynamic range, significant changes in target range can lead to changes in signal propagation delay, thus affecting the accuracy of Doppler parameter calculation. Existing solutions typically treat Doppler and range as independent parameters, neglecting the coupling relationship between them.

[0030] Fifth, the radar cross section (RCS) fluctuation characteristics of different targets are difficult to control independently. In real-world environments, the RCS characteristics of different targets vary greatly. For example, ship targets exhibit slow RCS fluctuations, while rotorcraft targets experience periodic obstruction effects. Existing solutions typically employ a uniform RCS model, making it difficult to independently control the RCS fluctuation characteristics of different targets.

[0031] Based on this, this application provides a multi-target radar echo simulation method. In this method, firstly, parameters can be configured for multiple targets to obtain configuration parameters for each target; wherein, the configuration parameters include motion parameters and radar cross section (RCS) fluctuation model parameters; then, the initial Doppler frequency shift value of each target can be calculated based on the configuration parameters of each target; wherein, each target is assigned an independent Doppler calculation channel; next, multiple targets that are detected to have intersecting trajectories can be separated; then, Doppler ambiguity compensation can be performed on each target based on its initial Doppler frequency shift value to obtain the true Doppler frequency shift value of each target; next, the true Doppler frequency shift value of each target can be coupled and corrected based on the range change rate of each target to obtain the corrected Doppler frequency shift value of each target; finally, a multi-target echo signal can be synthesized based on the corrected Doppler frequency shift value of each target and the RCS fluctuation model. Based on this, in this application, since each target is assigned an independent Doppler calculation channel, this application has high scalability compared to the prior art. In addition, since complex trajectory intersection detection and separation processing is performed on each target, this application can accurately simulate complex scenarios such as multi-target intersection, lane splitting, and convergence, avoiding Doppler aliasing, compared to the prior art. Furthermore, since Doppler blur compensation is performed on each target, this application can effectively solve the Doppler blur problem of high-speed targets, expanding the speed simulation range of the system, compared to the prior art. In addition, since the true Doppler frequency shift value of each target is corrected, this application can improve the Doppler calculation accuracy in large dynamic range scenarios through correction, compared to the prior art.

[0032] After introducing the design concept of the embodiments of this application, the following is a brief introduction to the application scenarios to which the technical solutions of the embodiments of this application can be applied. It should be noted that the application scenarios described below are only for illustrating the embodiments of this application and are not intended to limit the scope. In specific implementation, the technical solutions provided by the embodiments of this application can be flexibly applied according to actual needs.

[0033] like Figure 1 The diagram shown illustrates an application scenario provided by an embodiment of this application. This application scenario may include a multi-target radar echo simulation device 10.

[0034] The multi-target radar echo simulation device 10 can be used to perform multi-target radar echo simulations, and can be, for example, a personal computer (PC), server, or laptop. The multi-target radar echo simulation device 10 may include one or more processors 101, memory 102, I / O interfaces 103, and database 104. Specifically, the processor 101 can be a central processing unit (CPU) or a digital processing unit, etc. The memory 102 can be volatile memory, such as random-access memory (RAM); the memory 102 can also be non-volatile memory, such as read-only memory, flash memory, hard disk drive (HDD), or solid-state drive (SSD); or the memory 102 can be any other medium capable of carrying or storing desired program code in the form of instructions or data structures that can be accessed by a computer, but is not limited thereto. The memory 102 can be a combination of the above-mentioned memories. The memory 102 can store some program instructions of the multi-target radar echo simulation method provided in the embodiments of this application. When these program instructions are executed by the processor 101, they can be used to implement the steps of the multi-target radar echo simulation method provided in the embodiments of this application, so as to solve the technical problems existing in the prior art, such as difficulty in supporting complex trajectory intersection scenarios and Doppler ambiguity. The database 104 can be used to store data such as configuration parameters, initial Doppler frequency shift values, ambiguous Doppler frequency shift values, true Doppler frequency shift values, range change rate and corrected Doppler frequency shift values ​​of each target involved in the scheme provided in the embodiments of this application.

[0035] In this embodiment, the multi-target radar echo simulation device 10 can obtain echo simulation instructions through the I / O interface 103. Then, the processor 101 of the multi-target radar echo simulation device 10 will solve the technical problems existing in the prior art, such as difficulty in supporting complex trajectory intersection scenarios and Doppler blur, according to the program instructions of the multi-target radar echo simulation method provided in this embodiment of the application stored in the memory 102. In addition, the configuration parameters of each target, the initial Doppler frequency shift value, the blurred Doppler frequency shift value, the true Doppler frequency shift value, the range change rate and the corrected Doppler frequency shift value can be stored in the database 104.

[0036] Of course, the methods provided in the embodiments of this application are not limited to... Figure 1 The application scenarios shown can also be used in other possible scenarios, and this application embodiment does not impose any limitations. Figure 1The functions that the various devices in the application scenarios shown can achieve will be described in subsequent method embodiments, and will not be elaborated on here. Below, the methods of the embodiments of this application will be described in conjunction with the accompanying drawings.

[0037] like Figure 2 The diagram shown is a flowchart illustrating a multi-target radar echo simulation method provided in this application embodiment. This method can... Figure 1 The multi-target radar echo simulation device 10 is used to perform this operation. Specifically, the process of this method is described below.

[0038] Step 201: Configure parameters for multiple targets to obtain the configuration parameters for each target.

[0039] The configuration parameters include motion parameters and radar cross section (RCS) fluctuation model parameters; the motion parameters include position information and velocity vector information.

[0040] Step 202: Calculate the initial Doppler frequency shift value of each target according to the configuration parameters of each target.

[0041] Each target is assigned an independent Doppler calculation channel.

[0042] Specifically, firstly, an independent Doppler calculation channel can be assigned to each target; among them, each Doppler calculation channel can work independently in parallel pipelines; in this application, an independent Doppler calculation module can be established for each target, with each calculation unit corresponding to one target, independently receiving three-dimensional velocity vector input and outputting Doppler frequency shift value, thereby realizing real-time processing of multiple targets.

[0043] Then, the radial velocity of each target can be calculated separately based on the configuration parameters of each target; that is, the radial velocity can be calculated based on the three-dimensional velocity vector received by each Doppler calculation module. The radial velocity of the target relative to the radar is calculated using the radar line-of-sight vector (the unit direction vector from the radar to the target). .

[0044] Finally, the radial velocity of each target can be used as a basis. Calculate the initial Doppler frequency shift value for each target. In this application, radial velocity can be used. Substitute the values ​​into the following formula for calculating the initial Doppler frequency shift to calculate the initial Doppler frequency shift of the target:

[0045] in, is the radar operating frequency; c is the speed of light.

[0046] Step 203: Separate multiple targets that have been detected to have intersected trajectories.

[0047] Specifically, for any two targets, firstly, the positions of the two targets at the next moment can be predicted based on the motion parameters (i.e., position and three-dimensional velocity vector) of the two targets at the current moment.

[0048] Then, it can be determined whether the predicted distance between the positions of any two targets at the next moment is less than a distance threshold.

[0049] Next, if it is determined that the predicted distance between the positions of any two targets at the next moment is less than the distance threshold, it can be determined that the trajectory of any two targets has intersected; otherwise, if it is determined that the predicted distance between the positions of any two targets at the next moment is not less than the distance threshold, it can be determined that the trajectory of any two targets has not intersected.

[0050] Finally, a time-domain separation strategy can be adopted to separate any two targets whose trajectories intersect, thereby allocating an independent time slot for each target in the echo signal to avoid Doppler aliasing.

[0051] Step 204: Based on the initial Doppler frequency shift values ​​of each target, perform Doppler ambiguity compensation on each target to obtain the true Doppler frequency shift values ​​of each target.

[0052] Specifically, firstly, the Doppler unambiguity range [-PRF / 2, PRF / 2] can be determined based on the set pulse repetition frequency (PRF).

[0053] Then, for any given target, it can be determined whether the initial Doppler frequency shift value of that target is within the Doppler unambiguity range. In this application, in order to improve the efficiency of multi-target radar echo simulation, Doppler ambiguity detection and compensation can be performed only on "high-speed targets" whose speed exceeds a speed threshold. That is, if it is determined that the speed of any given target exceeds a speed threshold, it is then determined whether the initial Doppler frequency shift value of that target is within the Doppler unambiguity range.

[0054] Next, if it is determined that the initial Doppler frequency shift value of any target is not within the Doppler unambiguous range, then modulo PRF operation can be performed on the initial Doppler frequency shift value of any target to obtain the ambiguous Doppler frequency shift value of any target. Conversely, if the initial Doppler frequency shift value of any target is determined to be within the range of Doppler ambiguity-free values, then the initial Doppler frequency shift value of any target is determined to be ambiguity-free.

[0055] The modulo PRF operation can be represented by the following formula:

[0056] in, The value represents the fuzzy Doppler frequency shift. The initial Doppler frequency shift value, The pulse repetition frequency; For modulo PRF operations. For example, 1200 Hz If it is 1000Hz, then, .

[0057] Then, a preset joint decision criterion can be used to determine the final fuzziness factor k of any one of the targets. Specifically, the preset joint decision criterion includes a "target maximum acceleration constraint" and a "Doppler rate of change variance minimum criterion".

[0058] Finally, based on the final blur factor and the blurry Doppler frequency shift value of any target, the true Doppler frequency shift value of any target is calculated. Among them, the true Doppler frequency shift value It can be expressed using the following formula:

[0059] in, This represents the true Doppler frequency shift value. The value represents the fuzzy Doppler frequency shift. For fuzzy multiples; This is the pulse repetition frequency.

[0060] Furthermore, when determining the final ambiguity factor of any target using a preset joint decision criterion, for any target, firstly, the measured Doppler frequency shift values ​​of M consecutive frames can be recorded; where M is a positive integer not less than 4.

[0061] Then, the measured Doppler frequency shift values ​​of M consecutive frames of any one target can be used as a basis. Calculate the candidate fuzziness multiples for any given target. The corresponding real Doppler sequence The actual Doppler sequence can be represented by the following formula: =M frames + ×PRF Next, the target maximum acceleration constraint and the real Doppler sequences corresponding to each candidate fuzziness factor can be used as the basis. For the multiple candidate fuzzy multiples Perform first-level filtering to obtain multiple first-level fuzzy multipliers. In this application, the maximum acceleration It is obtained by user setting, and the preset target maximum acceleration constraint can be expressed by the following formula:

[0062] in, The Doppler change rate between adjacent frames is given by the true Doppler sequence. get; The radar repetition frequency period is the time interval between two adjacent transmitted pulses of the radar, which is the reciprocal of the pulse repetition frequency (PRF): T_pri = 1 / PRF; is the radar operating frequency; c is the speed of light. Furthermore, if the candidate ambiguity factor... The corresponding real Doppler sequence If the preset target maximum acceleration constraint is met, then the candidate fuzzy factor is considered to be... It passed the first-level screening and became a first-level fuzzy multiplier. .

[0063] Then, based on the minimum variance criterion of Doppler rate of change and each first-order ambiguity factor, the following can be applied: The corresponding real Doppler sequence For the multiple first-level fuzzy multiples A second-level screening is performed to obtain the final ambiguity factor k for any given target. In this application, the preset Doppler rate of change variance minimum criterion can be expressed by the following formula:

[0064] in, True Doppler sequence Doppler rate of change; Doppler rate of change The variance; Doppler rate of change The covariance. Furthermore, after calculating each first-order fuzzy factor... Corresponding Doppler rate of change variance Then, the first-order ambiguity factor with the smallest variance of the Doppler rate of change can be selected. As the final fuzziness factor k.

[0065] Step 205: Based on the distance change rate of each target, perform coupling correction on the true Doppler frequency shift value of each target to obtain the corrected Doppler frequency shift value of each target.

[0066] Specifically, firstly, based on the movement distance R of each target, the rate of change of distance for each target is calculated. In this application, the distance change rate It can be expressed using the following formula:

[0067] Where R is the distance the target has moved. That is, by differentiating the distance the target has moved, we can obtain the rate of change of the target's distance. In practical applications, according to the following phase change calculation formula, it can be seen that changes in distance will cause additional phase changes.

[0068]

[0069] Where φ is the additional phase; λ is the wavelength, and .

[0070] Based on this, the additional phase can be differentiated with respect to time t to obtain the coupled Doppler frequency. The coupled Doppler component (i.e., the coupling coefficient) is calculated using the following formula:

[0071] Therefore, it is possible to directly determine the rate of change of distance to each target. To determine the coupling coefficient of each target. In practical applications, the coupling coefficient can be determined by deriving the physical formula for the coupling coefficient and then fine-tuning it according to the radar system and target characteristics. The value is 2.

[0072] Next, we can determine the rate of change of distance to each target. With coupling coefficient The true Doppler frequency shift values ​​of each target were analyzed separately. Coupling correction is performed to obtain the corrected Doppler frequency shift values ​​for each target. In this application, the corrected Doppler frequency shift values... It can be expressed using the following formula:

[0073] Step 206: Synthesize multi-target echo signals based on the corrected Doppler frequency shift values ​​and RCS wave model of each target.

[0074] Specifically, firstly, independent RCS fluctuation models can be configured for each target based on the RCS fluctuation model parameters of each target; wherein, the RCS fluctuation model can support any one of the Swerling 0 / I / II / III / IV models.

[0075] Then, based on the RCS fluctuation model of each target, the instantaneous RCS parameters of each target can be calculated separately. .

[0076] Next, the corrected Doppler frequency shift, RCS parameters and initial phase of each target can be subjected to complex exponential modulation to generate the baseband echo signal of each target.

[0077] Finally, the baseband echo signals of each target can be summed by power weighting to obtain a multi-target synthesized echo signal and output it.

[0078] In one possible implementation, in order to solve the problem that the RCS fluctuation characteristics of different targets are difficult to control independently, this application also designs a "dynamic RCS fluctuation model switching mechanism", that is, the RCS fluctuation model can be dynamically switched according to the target attitude angle change rate.

[0079] Specifically, for any target, firstly, the attitude angle change rate θ_dot of any target can be calculated based on the target's position and three-dimensional velocity vector.

[0080] Then, it can be determined whether the rate of change of attitude angle θ_dot is greater than the rate of change threshold.

[0081] Next, if the attitude angle change rate θ_dot is determined to be greater than the change rate threshold, the target can be switched from the current RCS fluctuation model to a more suitable RCS fluctuation model with a higher angle change rate. During the dynamic switching of the RCS fluctuation model, a weighted smooth transition strategy can be used to avoid abrupt changes in RCS parameters. Conversely, if the attitude angle change rate θ_dot is determined not to be greater than the change rate threshold, the target will still use the current RCS fluctuation model to calculate its RCS parameters. .

[0082] In one possible implementation, the multi-target radar echo simulation can be implemented using a field-programmable gate array (FPGA) to reduce resource occupancy.

[0083] Specific experimental examples: Assuming that FPGA is used to simulate multi-target radar echoes, there are 16 targets, and each target is allocated an independent Doppler calculation channel using a pipelined parallel architecture.

[0084] Based on this, the processing delay is approximately 8 μs when performing multi-target radar echo simulation, meeting the real-time requirement of 100 μs PRT. The 32-bit fixed-point accuracy meets the Doppler simulation accuracy requirements for radar system testing.

[0085] In summary, this application has the following advantages: (1) High scalability: Due to the adoption of an independent Doppler computing channel architecture, each target corresponds to an independent computing unit. Therefore, it is easy to expand to support more targets without affecting real-time performance.

[0086] (2) Complex trajectory processing capability: Due to the execution of trajectory intersection detection and Doppler separation processing, it can accurately simulate complex scenarios such as multi-target intersection, lane splitting, and convergence, and avoid Doppler aliasing.

[0087] (3) High-speed target adaptability: Due to the adoption of a preset joint decision criterion (preset acceleration constraint-variance joint decision criterion) to perform Doppler fuzzy compensation, the Doppler fuzzy problem of high-speed targets can be effectively solved, and the speed simulation range of the system can be expanded.

[0088] (4) High computational accuracy: Since the real Doppler frequency shift value is coupled and corrected based on the phase change physical formula and the distance change rate of each target, the Doppler computational accuracy in large dynamic range scenarios is improved.

[0089] (5) Flexible RCS control: Since it can support the independent configuration of RCS wave models for different targets and realize the dynamic RCS wave model switching based on the attitude angle change rate, it can simulate the scattering characteristics of various types of targets such as ships, aircraft, and vehicles.

[0090] (6) Hardware-friendly implementation: Since each Doppler computing module adopts an independent pipelined parallel architecture, it is easy to implement efficiently on programmable logic devices such as FPGA.

[0091] Based on the same inventive concept, embodiments of this application provide a multi-target radar echo simulation system 30, such as... Figure 3 As shown, the multi-target radar echo simulation system 30 includes: The parameter configuration unit 301 is used to configure parameters for multiple targets and obtain configuration parameters for each target; wherein, the configuration parameters include motion parameters and radar cross section (RCS) fluctuation model parameters. The Doppler calculation unit 302 is used to calculate the initial Doppler frequency shift value of each target according to the configuration parameters of each target; wherein, each target is assigned an independent Doppler calculation channel; The trajectory intersection detection unit 303 is used to separate multiple targets that have been detected to have trajectory intersections; The fuzzy compensation unit 304 is used to perform Doppler fuzzy compensation on each target based on the initial Doppler frequency shift value of each target, so as to obtain the true Doppler frequency shift value of each target. The coupling correction unit 305 is used to perform coupling correction on the true Doppler frequency shift value of each target according to the distance change rate of each target, so as to obtain the corrected Doppler frequency shift value of each target. The echo synthesis unit 306 is used to synthesize multi-target echo signals based on the corrected Doppler frequency shift value and RCS wave model of each target.

[0092] Optionally, the Doppler computing unit 302 is also used for: Each target is assigned an independent Doppler calculation channel; these Doppler calculation channels operate in parallel. Calculate the radial velocity of each target based on its configuration parameters; Based on the radial velocity of each target, the initial Doppler shift value of each target is calculated.

[0093] Optionally, the trajectory intersection detection unit 303 is also used for: For any two targets, predict their positions at the next moment based on their motion parameters at the current moment. Determine whether the predicted distance between the positions of any two targets at the next moment is less than a distance threshold; If the predicted distance between the positions of any two targets at the next moment is less than the distance threshold, then it is determined that the trajectories of any two targets intersect. A time-domain separation strategy is adopted to separate any two targets.

[0094] Optionally, the fuzzy compensation unit 304 is also used for: The Doppler unambiguity range is determined based on the set pulse repetition frequency (PRF). For any given target, determine whether the initial Doppler frequency shift value of the target is within the Doppler unambiguity range; If it is determined that the initial Doppler frequency shift value of any target is not within the Doppler unambiguous range, then perform modulo PRF operation on the initial Doppler frequency shift value of any target to obtain the ambiguous Doppler frequency shift value of any target. The final fuzzy factor of any target is determined by using a pre-defined joint decision criterion; the pre-defined joint decision criterion includes the target maximum acceleration constraint and the Doppler rate of change variance minimum criterion. Calculate the true Doppler shift value of any target based on its final blur factor and blurry Doppler shift value.

[0095] Optionally, the fuzzy compensation unit 304 is also used for: Based on the measured Doppler frequency shift values ​​of M consecutive frames for any target, calculate the true Doppler sequence corresponding to each candidate blur factor of any target; where M is a positive integer not less than 4; Based on the target maximum acceleration constraint and the real Doppler sequence corresponding to each candidate fuzzy factor, a first-level screening is performed on multiple candidate fuzzy factors to obtain multiple first-level fuzzy factors. Based on the minimum variance criterion of Doppler rate of change and the real Doppler sequences corresponding to each first-level ambiguity factor, a second-level screening is performed on multiple first-level ambiguity factors to obtain the final ambiguity factor of any target.

[0096] Optionally, the coupling correction unit 305 is also used for: Calculate the rate of change of distance for each target based on the distance it has traveled. The coupling coefficient of each target is determined based on the rate of change of distance to each target. Based on the distance change rate and coupling coefficient of each target, the true Doppler frequency shift value of each target is coupled and corrected to obtain the corrected Doppler frequency shift value of each target.

[0097] Optionally, the echo synthesis unit 306 is also used for: Configure an independent RCS fluctuation model for each target; Based on the RCS fluctuation model of each target, calculate the RCS parameters of each target respectively; The corrected Doppler frequency shift, RCS parameter and initial phase of each target are subjected to complex exponential modulation to generate the baseband echo signal of each target; The baseband echo signals of each target are summed by power weighting to obtain the multi-target composite echo signal.

[0098] The multi-target radar echo simulation system 30 can be used to perform... Figure 2 Therefore, the functions that each functional module of the multi-target radar echo simulation system 30 can achieve, as shown in the method, can be referred to Figure 2 The embodiments shown are described in detail below.

[0099] In some possible implementations, various aspects of the methods provided in this application can also be implemented as a program product comprising program code that, when run on a computer device, causes the computer device to perform the steps of the methods according to the various exemplary embodiments of this application described above. For example, the computer device may perform actions such as... Figure 2 The method shown.

[0100] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks. Alternatively, if the integrated units of this application are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, or the parts that contribute to the prior art, can be embodied in the form of software products. These computer software products are stored in a storage medium and include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.

[0101] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0102] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for simulating multi-target radar echoes, characterized in that, The method includes: Parameters are configured for multiple targets to obtain configuration parameters for each target; wherein, the configuration parameters include motion parameters and radar cross section (RCS) fluctuation model parameters; Based on the configuration parameters of each target, the initial Doppler frequency shift value of each target is calculated; each target is assigned an independent Doppler calculation channel. Separate multiple targets whose trajectories intersect; Based on the initial Doppler frequency shift values ​​of each target, Doppler ambiguity compensation is performed on each target to obtain the true Doppler frequency shift values ​​of each target; Based on the distance change rate of each target, the true Doppler frequency shift value of each target is coupled and corrected to obtain the corrected Doppler frequency shift value of each target. Based on the corrected Doppler frequency shift values ​​and RCS wave model of each target, multi-target echo signals are synthesized.

2. The method as described in claim 1, characterized in that, The step of calculating the initial Doppler frequency shift value of each target based on the configuration parameters of each target includes: Each target is assigned an independent Doppler calculation channel; these Doppler calculation channels operate in parallel. Calculate the radial velocity of each target based on its configuration parameters; Based on the radial velocity of each target, the initial Doppler shift value of each target is calculated.

3. The method as described in claim 1, characterized in that, The step of separating multiple targets that have been detected to have intersecting trajectories includes: For any two targets, predict the positions of the two targets at the next moment based on the motion parameters of the two targets at the current moment; Determine whether the predicted distance between the positions of any two targets at the next moment is less than a distance threshold; If it is determined that the predicted distance between the positions of any two targets in the next moment is less than the distance threshold, then it is determined that the trajectories of any two targets intersect. A time-domain separation strategy is adopted to separate any two targets.

4. The method as described in claim 1, characterized in that, The step of performing Doppler ambiguity compensation on each target based on its initial Doppler frequency shift value to obtain the true Doppler frequency shift value of each target includes: The Doppler unambiguity range is determined based on the set pulse repetition frequency (PRF). For any given target, determine whether the initial Doppler frequency shift value of the target is within the range of Doppler ambiguity-free conditions; If it is determined that the initial Doppler frequency shift value of any target is not within the Doppler unambiguous range, then the initial Doppler frequency shift value of any target is subjected to modulo PRF operation to obtain the ambiguous Doppler frequency shift value of any target. The final fuzzy factor of any target is determined by adopting a preset joint decision criterion; wherein the preset joint decision criterion includes the target maximum acceleration constraint and the Doppler rate of change variance minimum criterion. Calculate the true Doppler shift value of any target based on its final blur factor and blurry Doppler shift value.

5. The method as described in claim 4, characterized in that, The step of determining the final fuzziness factor of any one target using a preset joint decision criterion includes: Based on the measured Doppler frequency shift values ​​of M consecutive frames of any target, calculate the true Doppler sequence corresponding to each candidate blur factor of any target; where M is a positive integer not less than 4; Based on the target maximum acceleration constraint and the real Doppler sequence corresponding to each candidate fuzziness factor, the multiple candidate fuzziness factors are subjected to a first-level screening to obtain multiple first-level fuzziness factors; Based on the minimum variance criterion of Doppler rate of change and the real Doppler sequence corresponding to each first-level ambiguity factor, a second-level screening is performed on the multiple first-level ambiguity factors to obtain the final ambiguity factor of any target.

6. The method as described in claim 1, characterized in that, The step of coupling and correcting the true Doppler frequency shift values ​​of each target based on the distance change rate of each target to obtain the corrected Doppler frequency shift values ​​of each target includes: Calculate the rate of change of distance for each target based on the distance it has traveled. The coupling coefficient of each target is determined based on the rate of change of distance to each target. Based on the distance change rate and coupling coefficient of each target, the true Doppler frequency shift value of each target is coupled and corrected to obtain the corrected Doppler frequency shift value of each target.

7. The method as described in claim 1, characterized in that, The step of obtaining the multi-target synthetic echo signal based on the corrected Doppler frequency shift value and RCS wave model of each target includes: Based on the RCS fluctuation model parameters of each target, an independent RCS fluctuation model is configured for each target. Based on the RCS fluctuation model of each target, calculate the RCS parameters of each target respectively; The corrected Doppler frequency shift, RCS parameter and initial phase of each target are subjected to complex exponential modulation to generate the baseband echo signal of each target; The baseband echo signals of each target are summed by power weighting to obtain the multi-target composite echo signal.

8. A multi-target radar echo simulation system, characterized in that, The system includes: The parameter configuration unit is used to configure parameters for multiple targets and obtain configuration parameters for each target; wherein, the configuration parameters include motion parameters and radar cross section (RCS) fluctuation model parameters; The Doppler calculation unit is used to calculate the initial Doppler frequency shift value of each target according to the configuration parameters of each target; wherein, each target is assigned an independent Doppler calculation channel; The trajectory intersection detection unit is used to separate multiple targets that are detected to have intersecting trajectories; The fuzzy compensation unit is used to perform Doppler fuzzy compensation on each target based on the initial Doppler frequency shift value of each target, so as to obtain the true Doppler frequency shift value of each target. The coupling correction unit is used to perform coupling correction on the true Doppler frequency shift value of each target according to the distance change rate of each target, so as to obtain the corrected Doppler frequency shift value of each target. The echo synthesis unit is used to synthesize multi-target echo signals based on the corrected Doppler frequency shift value and RCS wave model of each target.

9. An electronic device, characterized in that, The device includes: Memory, used to store program instructions; A processor is configured to invoke program instructions stored in the memory and execute the method described in any one of claims 1-7 according to the obtained program instructions.

10. A storage medium, characterized in that, The storage medium stores computer-executable instructions for causing a computer to perform the method described in any one of claims 1-7.

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