Radar target CPI echo simulation generation method and system based on accurate electromagnetic calculation

Abstract

The invention belongs to the technical field of radars, and discloses a radar target CPI echo simulation generation method based on accurate electromagnetic calculation. According to the method, target omni-directional broadband electromagnetic scattering characteristics are obtained based on commercial accurate electromagnetic calculation software, and influences of antenna pattern modulation, a target fluctuation model, a Doppler effect and signal processing response are introduced under the conditions of given target course, speed, radar parameters and the like; generalized radar target coherent or non-coherent CPI pulse group echoes suitable for any radar parameters and target type conditions are generated through simulation, the method can be suitable for different targets and radar types, and the credibility of target echo simulation is remarkably improved. According to the method, target omnibearing broadband electromagnetic scattering characteristics are obtained based on commercial accurate electromagnetic calculation software, universal radar target coherent or non-coherent CPI pulse group echoes suitable for any radar parameters and target type conditions are generated through simulation, the method can be suitable for different targets and radar types, and the credibility of target echo simulation is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of radar technology, and in particular relates to a radar target CPI echo simulation generation method and system based on precise electromagnetic calculation. Background Art

[0002] Radar target echo simulation is an indispensable auxiliary means for the design and performance verification of modern radar systems. Existing radar target echo simulation methods are mainly divided into three categories: pure model-based full digital simulation, semi-physical simulation based on actual installation data, and full physical simulation. Physical simulation and semi-physical simulation methods have significant advantages of high credibility, but their versatility is limited and it is difficult to cover all types of targets that appear. Existing model-based full digital simulation methods are generally based on point target models, without considering the influence of fine geometric features of targets and changes in navigation attitude. The simulated echo signals have different degrees of poor credibility, and the processing response of the radar system is not fine enough, especially it is difficult to reflect the modulation effect of the mechanical scanning radar antenna beam pattern on the echo within the entire CPI; the target fluctuation is completely based on the Swerling model, which cannot reflect the physical nature of the fluctuation of the echo amplitude caused by changes in target attitude and radar viewing angle.

[0003] Through the above analysis, the problems and defects of the prior art are as follows: Traditional radar system simulations are mostly based on point target models to generate single-pulse target echo signals, which are difficult to adapt to the high-range resolution applications of modern radar systems and cannot effectively reflect the fine structural characteristics of the target. The modulation effects caused by the antenna pattern within the coherent processing interval (CPI) are also insufficiently considered. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a radar target CPI echo simulation generation method based on precise electromagnetic calculation.

[0005] The present invention is implemented in that a radar target CPI echo simulation generation method based on accurate electromagnetic calculation comprises: Step 1, determine radar operating parameters; Step 2: Determine the radar center viewing angle based on the target motion heading and the relative geometric position of the radar target and the observation center elevation ; Step 3: In the radar operating frequency band B, The center uses the frequency diversity method to calculate the target complex RCS characteristic data at different fixed frequencies at different times within the pulse; Step 4: Use the IFFT algorithm to determine the inversion and The one-dimensional range image of the radar target is obtained, and a database of the target's broadband scattering characteristics is constructed from it; Step 5: Accumulate pulses in CPI Inside, with and As the center, query the target broadband scattering characteristic database to obtain the target basic broadband scattering characteristics; Step 6, introduce the influence of target fluctuation characteristics, distinguish different target types according to the Swerling target fluctuation model, and obtain the target scattering characteristic data matrix in the CPI; Step 7, introducing the influence of antenna beam modulation effect; Step 8: Introduce the influence of radar receiving processing response characteristics.

[0006] Further, the radar operating parameters are determined: Specifically include: Center operating frequency , polarization mode, working bandwidth .

[0007] Furthermore, the target basic broadband scattering characteristics are pre-calculated by a generalized accurate electromagnetic calculation method or commercial electromagnetic calculation software based on a given target geometric model, and are denoted as .

[0008] Furthermore, the target scattering characteristic data matrix in the CPI is: ,in , (1) In the formula, A random variable sequence that satisfies the fluctuation characteristics and random distribution characteristics specified by the Swerling model; right The data matrix introduces the influence of the radial velocity of the target motion, that is, the new correction matrix is: (2).

[0009] Furthermore, the influence of the introduced antenna beam modulation effect is calculated using the following formula: (3) In the formula, It is the one-way radiation pattern function of the antenna. The measured radar antenna radiation pattern can be used, or it can be simulated based on the main lobe radiation pattern function of the classic radar antenna. Typical antenna main lobe radiation pattern simulation functions include Gaussian function and cosine square function.

[0010] Furthermore, the impact of introducing radar receiving processing response characteristics is as follows: For the data matrix , the influence of filtering processing is introduced in the range and Doppler domains. Since the influence of pulse compression has been considered in the process of generating one-dimensional range images, only the influence of pulse envelope receiving processing needs to be considered in the range dimension; for simple pulses, the ambiguity function is (4) In the formula, is the pulse width, For delay, is the frequency shift difference; For a single pulse, considering the influence of receiver matched filtering, the corrected echo data matrix can be obtained as (5) The influence of Doppler filter characteristics can be introduced based on the specific frequency response characteristics of the filter; the frequency response characteristics of the radar Doppler filter are , then the updated data matrix is (6) When the Doppler filtering process is directly implemented using the FFT algorithm, (7) in, is the filter number where the target Doppler is located, is the number of channels of the filter bank; (8).

[0011] Another object of the present invention is to provide a radar target CPI echo simulation generation system based on accurate electromagnetic calculation, comprising: Determination module, used to determine the radar working parameters; according to the target movement heading and the relative geometric position relationship between the radar target, determine the radar center viewing angle and the observation center elevation ; The calculation module is used in the radar working frequency band B to The center uses the frequency diversity method to calculate the target complex RCS characteristic data at different fixed frequencies at different times within the pulse; Building blocks for applying the IFFT algorithm to invert the determined and The one-dimensional range image of the radar target is obtained, and a database of the target's broadband scattering characteristics is constructed from it; Query module, used to accumulate pulses in CPI Inside, with and As the center, query the target broadband scattering characteristic database to obtain the target basic broadband scattering characteristics; The introduction module is used to introduce the influence of target fluctuation characteristics, distinguish different target types based on the Swerling target fluctuation model, and obtain the target scattering characteristic data matrix within the CPI; introduce the influence of antenna beam modulation effect; introduce the influence of radar receiving processing response characteristics.

[0012] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation.

[0013] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to perform the steps of the method for simulating and generating radar target CPI echoes based on precise electromagnetic calculations.

[0014] Another object of the present invention is to provide an information data processing terminal, which is used to implement the radar target CPI echo simulation generation system based on precise electromagnetic calculation.

[0015] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows: First, starting from the physical mechanism of target scattering, the present invention first obtains the all-round high-resolution one-dimensional range image feature data of a given target at a specific radar operating frequency based on commercial electromagnetic computing software. On this basis, based on the input parameter conditions such as target heading and speed, target motion fluctuation model, actual radar range resolution, antenna beam pattern, signal processing method, etc., the linear system analysis and processing model is used to simulate and generate target coherent echo or non-coherent echo data within the CPI, which can significantly improve the credibility of radar target echo simulation and directly reflect the individual characteristics of the target and the physical mechanism in the echo generation process.

[0016] The present invention proposes to obtain the target's omnidirectional broadband electromagnetic scattering characteristics based on commercial precise electromagnetic calculation software, introduce the influence of antenna pattern modulation, target fluctuation model, Doppler effect, and signal processing response under given target heading, speed, and radar parameters, and simulate and generate universal radar target coherent or non-coherent CPI pulse group echoes suitable for arbitrary radar parameters and target type conditions. It can be applicable to different targets and radar types, and significantly improve the credibility of target echo simulation.

[0017] Second, the technical solution of the present invention overcomes technical prejudice: The technical solution of the present invention effectively overcomes the problems in traditional radar target echo simulation that the individual scattering characteristics of the target cannot be reflected, the influence of the target's navigation posture cannot be reflected, and the problem that the target can not be applied to high-resolution radar and range-extended target scenarios is not solved. The omnidirectional broadband electromagnetic scattering characteristics of the target are obtained through precise electromagnetic calculations. By introducing models of antenna beam modulation, range Doppler reception processing response, target fluctuation characteristics, etc., the system comprehensively considers the full range of spatial, temporal and frequency characteristics, which is suitable for the application needs of high-fidelity simulation and high-precision simulation of radar echoes.

[0018] Third, the innovation and progress of the technical solution of the present invention in industrial application are summarized as follows: 1. Accurate electromagnetic calculations to achieve high-fidelity echo simulation Based on accurate electromagnetic calculation methods, the present invention combines the broadband scattering characteristics of the target and the radar operating parameters to provide a high-fidelity radar target CPI echo simulation generation method. By constructing a target broadband scattering characteristic database and comprehensively considering the target motion characteristics, fluctuation model, antenna beam modulation effect and radar receiving and processing response characteristics, a comprehensive and accurate simulation of radar target echoes is achieved, filling the gap in the existing simulation methods in depicting real physical phenomena.

[0019] 2. Construction of broadband scattering characteristics database By adopting the frequency diversity method within the radar working band, the complex RCS characteristic data of the target at different frequencies and observation angles are calculated, and the IFFT algorithm is used to invert and generate a one-dimensional range image, thus building a comprehensive database of target broadband scattering characteristics. This database is queried and applied in CPI to provide basic data support for simulation, which significantly improves the efficiency and accuracy of target scattering characteristic calculation compared with traditional methods.

[0020] 3. Introducing accurate modeling of target fluctuation characteristics and motion effects The present invention introduces the Swerling target fluctuation model, generates a target scattering characteristic data matrix in the CPI after distinguishing different target types, and further corrects the target scattering characteristic matrix in combination with the radial velocity of the target motion. This step makes up for the defect of insufficient consideration of the influence of target motion and fluctuation characteristics in the prior art, and enhances the adaptability of the simulation method to complex target scenes.

[0021] 4. Simulation of antenna beam modulation and radar receiving response By introducing the modulation effect of the antenna pattern and combining the actual or simulated antenna main lobe pattern function (such as Gaussian function, cosine square function), the intensity change of the target echo signal at the antenna receiving end is simulated. At the same time, considering the influence of the radar receiving processing characteristics on the target echo, the realism of the simulation method is improved from the perspective of the integrity of the signal processing chain.

[0022] 5. Wide applicability and high computing efficiency The present invention covers the modeling of target broadband scattering characteristics, analysis of motion fluctuations, and joint simulation of radar antenna and receiving characteristics, forming a complete set of CPI echo simulation methods. Its core algorithm uses IFFT and matrix operations, with high computational efficiency, and is suitable for the simulation needs of various radar systems and target types, and can be expanded to complex scene simulations.

[0023] 6. Significant technological progress in industrial applications This method overcomes the shortcomings of existing technologies in simulation accuracy and physical reality, and provides an accurate simulation tool for radar design and performance evaluation by modeling the target and radar characteristics in multiple dimensions. Especially in the fields of aerospace, national defense, and high-resolution radar research and development, this method significantly improves the reality of target simulation scenes, reduces system development and verification costs, and has important application value and promotion prospects.

[0024] In summary, the present invention provides a new idea for radar target echo simulation through precise electromagnetic calculation and systematic modeling, which has significant technological progress and industrial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of a radar target CPI echo simulation generation method based on precise electromagnetic calculation provided by an embodiment of the present invention.

[0026] Figure 2 It is a structural block diagram of a radar target CPI echo simulation generation system based on precise electromagnetic calculation provided by an embodiment of the present invention.

[0027] Figure 3 It is a schematic diagram of generating target coherent CPI pulse group echo data provided by an embodiment of the present invention.

[0028] Figure 4 It is a simulation algorithm workflow diagram provided by an embodiment of the present invention.

[0029] Figure 5 It is a precise electromagnetic computational geometry model diagram of some typical ship targets provided by an embodiment of the present invention.

[0030] Figure 6 This is a one-dimensional high-resolution range image of an Arleigh Burke-class destroyer provided by an embodiment of the present invention.

[0031] Figure 7 This is a one-dimensional high-resolution range image (ship length 26 meters) of a civilian ship provided by an embodiment of the present invention.

[0032] Figure 8 It is a diagram of the antenna pattern function used for modeling provided by an embodiment of the present invention.

[0033] Fig. 9 This is a CPI inner echo diagram after taking into account the antenna beam scanning modulation effect, provided by an embodiment of the present invention.

[0034] Fig.10 This is a CPI intra-echo diagram after considering the target pulse-to-pulse fluctuation effect provided by an embodiment of the present invention.

[0035] Fig.11 This is a CPI target echo video image provided by an embodiment of the present invention.

[0036] Fig.12 This is a range-Doppler domain target echo diagram provided by an embodiment of the present invention.

[0037] Fig.13 It is a curve diagram of the distance-dimensional echo processing response characteristics used in the modeling and simulation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] Specific industrial application examples: Example 1: Target characteristics verification of high-resolution radar In the development and testing of high-resolution imaging radars (such as SAR and ISAR), it is necessary to simulate the echo signals of complex targets to verify the radar's target resolution capability and the performance of the echo processing algorithm. The target CPI echo simulation method based on precise electromagnetic calculation of the present invention can provide real and accurate data support for the generation of radar echo signals of different targets. Specific application scenarios include: 1. Radar imaging accuracy verification By constructing a broadband scattering characteristic database containing targets of different geometric shapes and materials, echo data of real targets are generated to verify the imaging accuracy and resolution capability of high-resolution radar under different target types, motion states and viewing angles.

[0040] 2. Target feature extraction algorithm test By combining the target's fluctuation characteristics and radial velocity effect, a variety of complex echo data are generated to test the radar system's target feature extraction and target recognition algorithm performance under noise and interference conditions, thereby improving the reliability and robustness of the radar system.

[0041] Example 2: Radar combat simulation in complex scenarios In the field of national defense and military, it is necessary to simulate and evaluate the performance of radar in complex combat scenarios. The CPI echo simulation method of the present invention can be applied to simulation scenarios with multiple targets and multiple motion states to generate target echo data with high fidelity. Specific application scenarios include: 1. Test of multi-target tracking capability of air defense radar The echo characteristics of multiple targets at different altitudes, speeds and azimuths are simulated, and the complex echo data in real combat scenarios are simulated to test the multi-target tracking and target threat priority sorting algorithm performance of air defense radar.

[0042] 2. Radar jamming and anti-jamming capability verification Antenna beam modulation and target fluctuation characteristics are added to the simulation to generate target data with different echo characteristics. This is used to evaluate the radar's target detection and resolution capabilities under interference conditions, as well as the effectiveness of anti-interference technology.

[0043] Through these embodiments, the simulation method of the present invention provides a real and reliable simulation environment for radar research and development and verification, which not only improves the system development efficiency, but also reduces the cost of actual testing, and has wide industrial application value.

[0044] like Figure 1 As shown, a radar target CPI echo simulation generation method based on precise electromagnetic calculation provided by an embodiment of the present invention includes the following steps: S101, determining radar operating parameters; S102, determine the radar center viewing angle according to the target motion heading and the relative geometric position relationship between the radar target and the observation center elevation ; S103, in radar operating band B, The center uses the frequency diversity method to calculate the target complex RCS characteristic data at different fixed frequencies at different times within the pulse; S104, using IFFT algorithm, the inversion is determined and The one-dimensional range image of the radar target is obtained, and a database of the target's broadband scattering characteristics is constructed from it; S105, the number of pulses that can be accumulated in CPI Inside, with and As the center, query the target broadband scattering characteristic database to obtain the target basic broadband scattering characteristics; S106, introducing the influence of target fluctuation characteristics, distinguishing different target types based on the Swerling target fluctuation model, and obtaining the target scattering characteristic data matrix in the CPI; S107, introduces the influence of antenna beam modulation effect; S108, introducing the influence of radar receiving processing response characteristics.

[0045] The radar operating parameters provided by the embodiment of the present invention are as follows: Specifically include: Center operating frequency , polarization mode, working bandwidth .

[0046] The target basic broadband scattering characteristic provided by the embodiment of the present invention is denoted as .

[0047] The target scattering characteristic data matrix in the CPI provided by the embodiment of the present invention is: ,in , (1) In the formula, A random variable sequence that satisfies the fluctuation characteristics and random distribution characteristics specified by the Swerling model; right The data matrix introduces the influence of the radial velocity of the target motion, that is, the new correction matrix is: (2).

[0048] Impact of introducing antenna beam modulation effect provided by the embodiment of the present invention: (3) In the formula, It is the one-way radiation pattern function of the antenna. The measured radar antenna radiation pattern can be used, or it can be simulated based on the main lobe radiation pattern function of the classic radar antenna. Typical antenna main lobe radiation pattern simulation functions include Gaussian function and cosine square function.

[0049] The impact of introducing radar receiving processing response characteristics provided by the embodiment of the present invention is as follows: For the data matrix , the influence of filtering processing is introduced in the range and Doppler domains. Since the influence of pulse compression has been considered in the process of generating one-dimensional range images, only the influence of pulse envelope receiving processing needs to be considered in the range dimension; for simple pulses, the ambiguity function is (4) In the formula, is the pulse width, For delay, is the frequency shift difference; For a single pulse, considering the influence of receiver matched filtering, the corrected echo data matrix can be obtained as (5) The influence of Doppler filter characteristics can be introduced based on the specific frequency response characteristics of the filter; the frequency response characteristics of the radar Doppler filter are , then the updated data matrix is (6) When the Doppler filtering process is directly implemented using the FFT algorithm, (7) in, is the filter number where the target Doppler is located, is the number of channels of the filter bank; (8).

[0050] like Figure 2 As shown, a radar target CPI echo simulation generation system based on precise electromagnetic calculation provided by an embodiment of the present invention includes: Determination module, used to determine the radar working parameters; according to the target movement heading and the relative geometric position relationship between the radar target, determine the radar center viewing angle and the observation center elevation ; The calculation module is used in the radar working frequency band B to The center uses the frequency diversity method to calculate the target complex RCS characteristic data at different fixed frequencies at different times within the pulse; Building blocks for applying the IFFT algorithm to invert the determined and The one-dimensional range image of the radar target is obtained, and a database of the target's broadband scattering characteristics is constructed from it; Query module, used to accumulate pulses in CPI Inside, with and As the center, query the target broadband scattering characteristic database to obtain the target basic broadband scattering characteristics; The introduction module is used to introduce the influence of target fluctuation characteristics, distinguish different target types based on the Swerling target fluctuation model, and obtain the target scattering characteristic data matrix within the CPI; introduce the influence of antenna beam modulation effect; introduce the influence of radar receiving processing response characteristics.

[0051] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation.

[0052] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to perform the steps of the method for simulating and generating radar target CPI echoes based on precise electromagnetic calculations.

[0053] Another object of the present invention is to provide an information data processing terminal, which is used to implement the radar target CPI echo simulation generation system based on precise electromagnetic calculation.

[0054] The present invention is specifically implemented: 1. Given the target geometry model, electrical characteristics model, radar operating frequency, viewing angle, polarization mode and other parameters, the above software can be used to quickly and easily obtain the static electromagnetic scattering characteristics data of complex targets. Based on this, the influence of relevant system factors such as target motion Doppler frequency shift, radar resolution unit parameters, antenna modulation effect, target fluctuation, receiving processing channel response, etc. is introduced to easily obtain the scattering characteristics data of the dynamic echo of the target in the CPI. The target coherent pulse group echo generation process based on precise electromagnetic calculation is as follows: Figure 3 shown.

[0055] First, for a specific radar system, the broadband one-dimensional range image of a typical target under different posture perspectives is accurately calculated in CST or FEKO to establish a high-resolution static scattering characteristic database of the target. On this basis, the original electromagnetic calculation data is gradually corrected considering the influence of factors such as the target RCS fluctuation, antenna pattern modulation, receiving processing response, and Doppler processing in the CPI, and finally the coherent pulse group echo data in the target CPI is obtained. The specific implementation algorithm and simulation steps are described as follows: (1) Determine the radar operating parameters, including: central operating frequency , polarization mode, working bandwidth ; (2) Determine the radar center viewing angle based on the target motion heading and the relative geometric position of the radar target and the observation center elevation ; (3) In radar operating band B, The center uses the frequency diversity method to calculate the target complex RCS characteristic data at different fixed frequencies at different times within the pulse; (4) Using the IFFT algorithm, the inversion is determined and The one-dimensional range image of the radar target is obtained, and a database of the target's broadband scattering characteristics is constructed from it; (5) Number of pulses that can be accumulated in CPI Inside, with and As the center, query the target broadband scattering characteristic database to obtain the target basic broadband scattering characteristics, which is recorded as ; (6) Introducing the influence of target fluctuation characteristics, different target types are distinguished based on the Swerling target fluctuation model to obtain the target scattering characteristic data matrix within the CPI ,in , (1) In the formula, A sequence of random variables that satisfies the fluctuation characteristics and random distribution characteristics specified by the Swerling model.

[0056] (6) Yes The data matrix introduces the influence of the radial velocity of the target motion, that is, the new correction matrix is: (2) (7) Influence of introducing antenna beam modulation effect (3) In the formula, It is the one-way radiation pattern function of the antenna. The measured radar antenna radiation pattern can be used, or it can be simulated based on the classic radar antenna main lobe radiation pattern function. Typical antenna main lobe radiation pattern simulation functions include Gaussian function, cosine square function, etc.

[0057] (8) Influence of introducing radar receiving and processing response characteristics For the data matrix , the influence of filtering processing is introduced in the range and Doppler domains. Since the influence of pulse compression has been considered in the one-dimensional range image generation process, only the influence of pulse envelope receiving processing needs to be considered in the range dimension. For a simple pulse, its ambiguity function is (4) In the formula, is the pulse width, For delay, is the frequency shift difference.

[0058] For a single pulse, considering the influence of receiver matched filtering, the corrected echo data matrix can be obtained as (5) The influence of Doppler filter characteristics can be introduced based on the specific frequency response characteristics of the filter. The frequency response characteristics of the radar Doppler filter are , then the updated data matrix is (6) When the Doppler filtering process is directly implemented using the FFT algorithm, (7) in, is the filter number where the target Doppler is located, is the number of channels of the filter bank.

[0059] (8) The CPI pulse group echo simulation generation algorithm based on the target broadband scattering characteristics is as follows: Figure 4 shown.

[0060] 1. Specific application fields or related products of the present invention.

[0061] The present invention is mainly used in the development process of radar training simulators, radar signal simulators, radar data simulators and other equipment and systems, and is used as a dedicated software function module or system function component device to generate high-precision and high-fidelity radar echo signal simulation.

[0062] 2. Relevant evidence of the technical effects obtained by the embodiments of the present invention.

[0063] In order to demonstrate the technical effect of the embodiment of the present invention, the application effect of the embodiment of the present invention is specifically described by taking the simulation process of the S-band radar echo signal of a typical ship target as an example.

[0064] Figure 5 The following are geometric model images of several typical ship targets to be simulated during the test. The radar center frequency was set to 3 GHz in the test, and horizontal polarization was used. In the CST electromagnetic calculation software, the relevant ships were modeled and calculated with a bandwidth of 300 MHz to obtain a one-dimensional high-resolution complex range image of the relevant target (range resolution 0.5 meters), thereby obtaining a database of the target's omnidirectional and full-elevation broadband scattering characteristics. Figure 5 Taking target (2) and target (7) as examples, the obtained one-dimensional high-resolution range images are shown in Figure 6 and Figure 7 , which mainly considers the application scenarios of shore-based and ship-borne radars detecting long-distance targets, and sets the grazing angle to 0°.

[0065] The one-dimensional linear array antenna pattern model is used as the antenna pattern function, and the Hanning window weighting method is used to suppress the side lobes to obtain the simulated antenna pattern. Figure 8 The figure shows the simulated effect of the radar antenna simulation pattern, where it is assumed that the number of radar transmitted and received pulses within the 3dB beam width of the radar antenna beam is 10.

[0066] The echo images of multiple pulses after antenna beam scanning modulation (under high resolution conditions) are as follows Fig. 9 As shown, the number of echo pulses in the CPI is taken as 41.

[0067] On this basis, we continue to consider the impact of target echo amplitude fluctuations between pulses and set the fluctuation factor , to reflect the impact of echo RCS fluctuations on radar echo amplitude. Taking the above two types of targets at an incident azimuth angle of 30° as an example, the processing results are as follows: Fig.10 As shown in the figure, the model successfully introduces the change of echo scattering intensity caused by the change of target posture between pulses, and the echo fluctuation attenuation between different pulses meets the randomness requirement.

[0068] We continue to consider the influence of Doppler frequency shift caused by radial motion of the target and the response characteristics of the radar receiving and processing system. In the distance dimension, we mainly introduce the fuzzy function distance dimension slice, and perform down-resolution processing on the above distance high-resolution echo data to match the working characteristics of the radar system to be analyzed. Thus, the final radar target CPI pulse group echo image is obtained, as shown in Fig.11 shown. Fig.12 The corresponding range-Doppler domain echo image is shown (the influence of Doppler filtering has been introduced), where the radial speed of the target is set to 9m / s, and the radar signal is in the form of a simple rectangular pulse (the range-dimensional echo processing response characteristic curve is shown in Fig.13 As shown in the figure), pulse width is 0.1us, repetition period is 1ms, and related parameters can be flexibly set according to actual radar working parameters.

[0069] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0070] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A radar target CPI echo simulation generation method based on precise electromagnetic calculation, characterized in that: The radar target CPI echo simulation generation method based on precise electromagnetic calculation comprises the following steps: Step 1, determine radar operating parameters; Step 2: Determine the radar center viewing angle based on the target motion heading and the relative geometric position of the radar target and the observation center elevation ; Step 3: In the radar operating frequency band B, The center uses the frequency diversity method to calculate the target complex RCS characteristic data at different fixed frequencies at different times within the pulse; Step 4: Use the IFFT algorithm to invert and determine and The one-dimensional range image of the radar target is obtained, and a database of the target's broadband scattering characteristics is constructed from it; Step 5: Accumulate pulses in CPI Inside, with and As the center, query the target broadband scattering characteristic database to obtain the target basic broadband scattering characteristics; Step 6, introduce the influence of target fluctuation characteristics, distinguish different target types according to the Swerling target fluctuation model, and obtain the target scattering characteristic data matrix in the CPI; Step 7, introducing the influence of antenna beam modulation effect; Step 8: Introduce the influence of radar receiving processing response characteristics.

2. The radar target CPI echo simulation generation method based on precise electromagnetic calculation as claimed in claim 1, characterized in that: Determining radar operating parameters: Specifically include: Center operating frequency , polarization mode, working bandwidth .

3. The radar target CPI echo simulation generation method based on precise electromagnetic calculation as claimed in claim 1, characterized in that: The target basic broadband scattering characteristic is denoted as .

4. The radar target CPI echo simulation generation method based on precise electromagnetic calculation as claimed in claim 1, characterized in that: The target scattering characteristic data matrix in the CPI is: ,in ， （1） In the formula, A random variable sequence that satisfies the fluctuation characteristics and random distribution characteristics specified by the Swerling model; right The data matrix introduces the influence of the radial velocity of the target motion, that is, the new correction matrix is: （2）。 5. The radar target CPI echo simulation generation method based on precise electromagnetic calculation as claimed in claim 1, characterized in that: The impact of introducing antenna beam modulation effect: （3） In the formula, It is the one-way radiation pattern function of the antenna. The measured radar antenna radiation pattern can be used, or it can be simulated based on the main lobe radiation pattern function of the classic radar antenna. Typical antenna main lobe radiation pattern simulation functions include Gaussian function and cosine square function.

6. The radar target CPI echo simulation generation method based on precise electromagnetic calculation as claimed in claim 1, characterized in that: The impact of introducing radar receiving processing response characteristics is as follows: For the data matrix , the influence of filtering processing is introduced in the range and Doppler domains. Since the influence of pulse compression has been considered in the process of generating one-dimensional range images, only the influence of pulse envelope receiving processing needs to be considered in the range dimension; for simple pulses, the ambiguity function is （4） In the formula, is the pulse width, For delay, is the frequency shift difference; For a single pulse, considering the influence of receiver matched filtering, the corrected echo data matrix can be obtained as （5） The influence of Doppler filter characteristics can be introduced based on the specific frequency response characteristics of the filter; the frequency response characteristics of the radar Doppler filter are , then the updated data matrix is （6） When the Doppler filtering process is directly implemented using the FFT algorithm, （7） in, is the filter number where the target Doppler is located, is the number of channels of the filter bank; （8）。 7. A radar target CPI echo simulation generation system based on precise electromagnetic calculation, which implements the radar target CPI echo simulation generation method based on precise electromagnetic calculation as claimed in any one of claims 1 to 6, characterized in that: The radar target CPI echo simulation generation system based on precise electromagnetic calculation includes: Determination module, used to determine the radar working parameters; according to the target movement heading and the relative geometric position relationship between the radar target, determine the radar center viewing angle and the observation center elevation ; The calculation module is used in the radar working frequency band B to The center uses the frequency diversity method to calculate the target complex RCS characteristic data at different fixed frequencies at different times within the pulse; Building blocks for applying the IFFT algorithm to invert the determined and The one-dimensional range image of the radar target is obtained, and a database of the target's broadband scattering characteristics is constructed from it; Query module, used to accumulate pulses in CPI Inside, with and As the center, query the target broadband scattering characteristic database to obtain the target basic broadband scattering characteristics; The introduction module is used to introduce the influence of target fluctuation characteristics, distinguish different target types based on the Swerling target fluctuation model, and obtain the target scattering characteristic data matrix within the CPI; introduce the influence of antenna beam modulation effect; introduce the influence of radar receiving processing response characteristics.

8. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation as described in any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation as described in any one of claims 1 to 6.

10. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the radar target CPI echo simulation generation system based on precise electromagnetic calculation as described in claim 7.

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