An online reconfigurable array radar target simulation method

Abstract

The present invention discloses an online reconfigurable array radar target simulation method, belonging to the field of radar target simulation technology. It solves the limitation design of the existing radar target simulator that is only used for a certain model of radar, and improves the versatility and expansibility of the array radar target simulator through online reconstruction. It is mainly composed of parameter calculation software and target generation software. The parameter calculation software is used to obtain simulator control instructions, radar parameters, simulated target parameters, generate radar scanning table parameters, simulated target parameters, and send them to the target generation software through the PCIE interface; the target generation software is implemented by FPGA programming, and is used to receive various parameter information, cache and solidify the scanning table information, generate radar working timing, parse simulated target parameter information, generate array radar N-channel target echo data that meets the requirements, and forward it through a custom optical fiber.

Description

Technical Field

[0001] The invention belongs to the technical field of radar echo simulation and is suitable for practical engineering applications of array radar target simulation. Background Art

[0002] Array radar target simulator is an indispensable part of function debugging, algorithm verification and performance testing in the development process of large array radar system. Radar target simulator combines digital simulation technology with radar technology to provide signal processing and data processing units with real-time data of all-round and multi-batch targets close to real echo targets under virtual conditions without actual array echo data.

[0003] Different radar parameters and different test contents have completely different requirements for the target echo data provided by the radar target simulator. The current radar target simulators are generally developed for a single radar. The radar working parameters and target parameters cannot be configured online, and the flexibility and versatility are poor. The target's motion characteristics are generally designed for several typical maneuvering tracks such as linear motion, horizontal circular motion, pitch-up maneuver and dive maneuver, which cannot truly reflect the characteristics of more real moving targets. There are also track models designed according to different target motion dynamics methods, which have relatively high accuracy, but the disadvantages are large calculations and complex modeling. Therefore, a general radar simulator with low hardware cost, easy to carry, and configurable radar parameters and simulated target parameters suitable for different radars is designed, which has a wide range of engineering application value. Summary of the invention

[0004] In order to solve the requirements of universality of array radar target simulator in the development process of different radars and arbitrary configuration of target form, the present invention proposes an online reconfigurable array radar target simulation method.

[0005] The technical solution to achieve the purpose of the present invention is:

[0006] Step 1: Set the radar working parameter information, including working frequency F, array number N, array element spacing S, and load the scanning information file;

[0007] Step 2: The parameter calculation software generates the wave position number, related pulse number, beam pointing, signal bandwidth, period, linear frequency modulation DDS parameters and nonlinear frequency modulation waveform library file according to the radar working parameter information, and sends it to the target generation software through the PCIE bus;

[0008] Step 3: The target generation software receives radar working parameters, generates radar working sequence, generates echo data, and solidifies radar parameters in FLASH;

[0009] Step 4: Set the simulated target parameters of the array radar, including the motion type model, target batch number P, target starting position W, acceleration a, velocity V, Doppler velocity Vd, and RCS amplitude;

[0010] Step 5: The parameter calculation software generates the reference simulation target parameters including distance, azimuth, speed, elevation angle, Doppler speed and the copy target parameters including azimuth batch number, distance batch number, distance step, and azimuth step according to the set simulation target parameters, and sends them to the target generation software;

[0011] Step 6: The target generation software receives the simulated target parameters, generates reference target echo data with superimposed elevation angle, Doppler velocity, and RCS amplitude, generates target data in distance and azimuth according to the method of copying target parameters, superimposes it on the radar echo data according to the working sequence, and forwards it through the custom optical fiber.

[0012] Furthermore, the radar's operating parameters and simulated target parameters are decomposed into operating frequency, number of arrays, array element spacing, scanning parameters, and simulated target parameters, and each parameter can be edited and reconstructed online.

[0013] The beneficial effects of the present invention include:

[0014] (1) By reconstructing radar operating parameters, it can be applied to array radars in different operating modes and generate radar target echo data of arbitrary waveforms;

[0015] (2) By configuring the simulated target parameters, radar echo data of any batch and any track within 2000 batches can be generated, which is suitable for different information processing and debugging requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the principle block diagram of the target simulation method;

[0017] Figure 2 Configure the flow chart for radar operating parameters;

[0018] Figure 3 Produce schematic diagrams for simulation targets;

[0019] Figure 4 Real-time calculation of schematic diagrams for benchmark targets;

[0020] Figure 5 Configure the flow chart for radar operating parameters;

[0021] Figure 6 Generates a logic flow chart for the simulation target. DETAILED DESCRIPTION

[0022] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0023] like Figure 1 As shown, the embodiment of the present invention is mainly composed of parameter calculation software and target generation software. The parameter calculation software is used to obtain radar working parameters, simulated target parameters, and point trace data, generate radar scanning parameters, waveform parameters, and simulated target parameters, and send them to the target generation software through the PCIE interface; the target generation software caches and solidifies the scanning table information, generates radar working timing, parses the simulated target parameter information, generates array radar N-channel target echo data that meets the requirements, and forwards it through a custom optical fiber.

[0024] The preferred embodiment of the present invention comprises the following steps:

[0025] Step 1: Set the radar working parameter information, including the working frequency F, the number of arrays N, and the array element spacing S, load the scanning information file, and realize the reconstruction of the radar working parameters. The scanning information file includes the wave position sorting, the number of related pulses, the beam pointing, and the waveform parameters. The waveform parameters include bandwidth, period, linear frequency modulation DDS parameters, and nonlinear frequency modulation waveform library files.

[0026] Step 2: The parameter calculation software generates the wave position number, related pulse number, beam pointing, signal bandwidth, period, linear frequency modulation DDS parameters and nonlinear frequency modulation waveform library file according to the radar working parameter information, and sends it to the target generation software through the PCIE bus when the software is initialized.

[0027] Step 3: The target generation software receives radar operating parameters, generates radar operating timing, produces echo data, and solidifies the radar parameters in FLASH.

[0028] like Figure 2 As shown in the figure, when the power-on initialization configuration is performed, the radar parameters solidified in the FLASH are read, the scanning parameter file and the waveform library file are parsed and cached, and the radar working timing is generated; at the same time, the message from the PCIE is parsed in real time, the parameters are updated, and the parameter message is cached in the FLASH for solidification.

[0029] Step 4: Set the simulated target parameters of the array radar, including motion type model, target batch number P, target starting position W, acceleration a, velocity V, Doppler velocity Vd, and RCS amplitude.

[0030] The parameters of the array radar target simulator include target batch number, target motion characteristics and target echo characteristics. The target motion characteristics include information such as distance, azimuth, acceleration, speed, heading, and elevation angle, and the target echo characteristics include information such as waveform type, amplitude, Doppler velocity, and target shape.

[0031] Step 5: The parameter calculation software calculates and generates the benchmark simulation target parameters including distance, azimuth, speed, elevation angle, Doppler speed and the copy target parameters including azimuth batch number, distance batch number, distance step and azimuth step in real time according to the set simulation target parameters, and sends them to the target generation software.

[0032] Considering the limitation of hardware resources and real-time computing, in order to meet the requirement of designing up to 2000 batches of targets for array radar target simulator, the design idea of ​​reference target and copy target is adopted. Figure 3 As shown, the parameter calculation software only needs one antenna scanning cycle to calculate the reference target parameters and send them to the target generation software. The current circle parameters are updated in the updated azimuth, the reference target is generated according to the reference target parameters, and the parameter information of the copy target is calculated according to the copy target parameters to generate the copy simulation target in azimuth and distance.

[0033] Assume that the trajectory of the reference target motion for two consecutive rounds of the target is as follows Figure 4 As shown, (Ai n ,Ri n ) is the nth reference target position coordinate, (Ai n-1 ,Ri n-1 ) is the position coordinate of the n-1th reference target. The radar antenna scanning period S, target azimuth Ai, distance Ri, elevation angle Bi, speed Vi, Doppler speed Vd, acceleration ai, number of circles n, maximum acceleration a0, radar repetition frequency Fr, c is the speed of light, and the angle between the motion direction of the two-circle reference target and the scanning line is defined as the radar centripetal angle θ. The real-time calculation formula of the reference target parameters is as follows:

[0034] The position of the nth reference target Ai n , distance Ri n for:

[0035]

[0036] Ri n =(Ri n-1 +(Vi+0.5*ai*S)*S)

[0037] The Doppler velocity Vd and velocity Vi of the nth reference target n for:

[0038]

[0039] Vi n =(Vi n-1 *cosθ+Vi n-1 *sinθ)+ai*S

[0040] Among them, ai=a0*cosθ+a0*sinθ, PRT is the radar repetition period of the current pulse, and the centripetal angle θ changes according to the motion characteristics of different targets. The calculation formula of the centripetal angle θ is as follows:

[0041]

[0042] in, ΔR=Vi*S; when the target moves tangentially, the centripetal angle θ=90°, and when the target moves tangentially, θ=0°.

[0043] like Figure 5 As shown, the parameter calculation software calculates the reference target parameters in each scanning cycle. After the current circle target is generated, the radar target parameters are calculated once, and the new radar simulation target parameters are sent to the target generation software at the updated azimuth position before the reference azimuth of the next circle. Compared with the traditional design method of calculating the track of each target in real time, the real-time requirements for CPU and PCIE transmission are reduced.

[0044] Step 6: The target generation software receives the simulated target parameters, generates reference target echo data with superimposed elevation angle, Doppler velocity, and RCS amplitude, generates target data in distance and azimuth according to the method of copying target parameters, superimposes it on the radar echo data according to the working sequence, and forwards it through the custom optical fiber.

[0045] The process by which target generation software generates targets, such as Figure 6As shown, when the real-time azimuth is equal to the updated azimuth, the target parameters of the current circle are updated; when the current pulse ends, the parameters of the next pulse are updated; it is judged in real time whether the number of targets on the current azimuth has been generated, and when the azimuth target counter is less than the azimuth target number, the target parameters of the next azimuth are calculated; when it is judged that the real-time azimuth is greater than the azimuth of the next target, it is judged whether the targets on the distance have been generated, and when the distance target counter is less than the distance target number, it is judged that the current distance is equal to the next target distance, and the parameter information of the next distance target is calculated; when it is judged that the current distance is greater than the next target distance, according to the waveform parameters of the current pulse, the DDS core of the FPGA is started to generate a linear frequency modulation baseband waveform or read the waveform library file, and the generated target I / Q data is weighted by the amplitude and phase coefficients, and modulated into N-channel echo simulation target data with amplitude, Doppler, and elevation information; when the distance target counter is greater than the distance target number, the current pulse distance target generation is completed; when the azimuth target counter is greater than the azimuth target number, the generation of azimuth targets is stopped. For radars with N arrays, this design method allows the target generation software to generate full-range, all-round simulated targets using only N DDS cores, ensuring that the number of target batches is not limited by FPGA resources.

[0046] Step 7: Send the simulated N-channel target echo data to the information processing unit through the customized optical fiber data.

[0047] The online reconfigurable array radar target simulation method of this embodiment can not only reconstruct radar operating parameters and configure simulated target parameters online, but also import point trace data of key targets collected in field experiments, and generate radar target echo data with real moving target characteristics through digital simulation. The contents not described in detail in the specification of the present invention belong to the prior art known to professional and technical personnel in this field.

[0048] Although the preferred embodiment and the accompanying drawings of the present invention are disclosed for illustrative purposes, it will be appreciated by those skilled in the art that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the disclosed contents of the preferred embodiment and the accompanying drawings.

Claims

1. An online reconfigurable array radar target simulation method, characterized in that: Step 1: Set the radar working parameter information, including working frequency F, array number N, array element spacing S, and load the scanning information file; Step 2: The parameter calculation software generates the wave position number, related pulse number, beam pointing, signal bandwidth, period, linear frequency modulation DDS parameters and nonlinear frequency modulation waveform library file according to the radar working parameter information, and sends it to the target generation software through the PCIE bus; Step 3: The target generation software receives radar working parameters, generates radar working sequence, generates echo data, and solidifies radar parameters in FLASH; Step 4: Set the simulated target parameters of the array radar, including the motion type model, target batch number P, target starting position W, acceleration a, velocity V, Doppler velocity Vd, and RCS amplitude; Step 5: The parameter calculation software generates the reference simulation target parameters including distance, azimuth, speed, elevation angle, Doppler speed and the copy target parameters including azimuth batch number, distance batch number, distance step, azimuth step according to the set simulation target parameters, and sends them to the target generation software; Step 6: The target generation software receives the simulated target parameters, generates reference target echo data with superimposed elevation angle, Doppler velocity, and RCS amplitude, generates target data in distance and azimuth according to the method of copying target parameters, superimposes it on the radar echo data according to the working sequence, and forwards it through the custom optical fiber.

2. The method for simulating an online reconfigurable array radar target according to claim 1, characterized in that: The radar's operating parameters and simulated target parameters are decomposed into operating frequency, array number, array element spacing, scanning parameters, and simulated target parameters, and each parameter can be edited and reconstructed online.

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