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

Abstract

This invention belongs to the field of radar technology and discloses a method for simulating and generating radar target CPI echoes based on precise electromagnetic calculations. This invention proposes to obtain the omnidirectional broadband electromagnetic scattering characteristics of a target using commercially available precise electromagnetic calculation software. Given the target's heading, speed, and radar parameters, it introduces the effects of antenna pattern modulation, target undulation model, Doppler effect, and signal processing response to simulate and generate a generalized radar target coherent or non-coherent CPI pulse group echo applicable to any radar parameters and target type. This method is applicable to different targets and radar types and significantly improves the reliability of target echo simulations.

Description

Technical Field

[0001] This invention belongs to the field of radar technology, and in particular relates to a method and system for simulating and generating radar target CPI echoes based on precise electromagnetic calculations. Background Technology

[0002] Radar target echo simulation is an indispensable auxiliary tool for modern radar system design and performance verification. Existing radar target echo simulation methods are mainly divided into three categories: pure model-based fully digital simulation, hardware-in-the-loop (HIL) simulation based on actual data, and full hardware-in-the-loop (WIL) simulation. WIL and HIL methods have significant advantages in high reliability, but their versatility is limited and they cannot cover all target types. Existing model-based fully digital simulation methods are generally based on point target models, failing to consider the effects of fine-grained target geometry and flight attitude changes. The simulated echo signals suffer from varying degrees of reliability issues, and the processing response of the radar system is not refined enough, particularly failing to reflect the modulation effect of the mechanically scanned radar antenna beam pattern on the echo within the entire CPI. Target fluctuations are entirely based on the Swerling model and cannot reflect the physical nature of echo amplitude fluctuations caused by changes in target attitude and radar viewing angle.

[0003] Based on the above analysis, the problems and shortcomings of the existing technology are as follows:

[0004] Traditional radar system simulations are mostly based on point target models to generate single-pulse target echo signals, which is difficult to adapt to the high range resolution of modern radar systems and cannot effectively reflect the fine structural features of the target; the modulation effect caused by the antenna pattern within the Coherent Processing Interval (CPI) is also not adequately considered. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for simulating and generating radar target CPI echoes based on precise electromagnetic calculations.

[0006] This invention is implemented as follows: A method for simulating and generating radar target CPI echoes based on precise electromagnetic calculations includes:

[0007] Step 1: Determine the radar operating parameters;

[0008] Step 2: Determine the radar center viewpoint based on the target's trajectory and the relative geometric position of the radar target. and the elevation angle of the observation center ;

[0009] Step 3, within the radar operating frequency band B, assuming... The center uses the frequency diversity method to calculate the complex RCS characteristic data of the target at different fixed frequencies at different times within the pulse.

[0010] Step 4: Use the IFFT algorithm to invert and obtain the determination. and A one-dimensional range profile of the radar target is obtained, and a broadband scattering characteristic database of the target is constructed accordingly.

[0011] Step 5, the number of pulses that can be accumulated in CPI. Inside, with and Using the target broadband scattering characteristics as the center, query the target broadband scattering characteristics database to obtain the target's basic broadband scattering characteristics;

[0012] Step 6: Introduce the influence of target fluctuation characteristics. Based on the Swerling target fluctuation model, distinguish different target types and obtain the target scattering characteristic data matrix within the CPI.

[0013] Step 7, introduce the influence of antenna beam modulation effect;

[0014] Step 8: Introduce the impact of radar receiver processing response characteristics.

[0015] Furthermore, the determination of radar operating parameters includes:

[0016] Specifically, this includes: central operating frequency Polarization mode, operating bandwidth .

[0017] Furthermore, the target's basic broadband scattering characteristics are pre-calculated from a given target geometric model using a generalized, precise electromagnetic calculation method or commercially available electromagnetic calculation software, denoted as... .

[0018] Furthermore, the target scattering characteristic data matrix within the CPI:

[0019] ,in

[0020] , (1)

[0021] In the formula, A sequence of random variables that meets the fluctuation characteristics and random distribution features specified by the Swerling model;

[0022] right The data matrix incorporates the influence of the target's radial velocity, resulting in the new correction matrix:

[0023] (2).

[0024] Furthermore, the effect of the introduced antenna beam modulation effect is calculated using the following formula:

[0025] (3)

[0026] In the formula, This is the antenna single-pass radiation pattern function. It can be simulated using the measured radar antenna radiation pattern or based on the classic radar antenna main lobe radiation pattern function. Typical antenna main lobe radiation pattern simulation functions include the Gaussian function and the cosine square function.

[0027] Furthermore, the impact of introducing radar receiver processing response characteristics:

[0028] For data matrix The influence of filtering in the range and Doppler domains is introduced. Since pulse compression has already been considered in the one-dimensional range image generation process, only the influence of pulse envelope reception processing needs to be considered in the range dimension. For simple pulses, the ambiguity function is...

[0029] (4)

[0030] In the formula, The pulse width. For time delay, This is the frequency shift difference;

[0031] For a single pulse, considering the effect of receiver matched filtering, the corrected echo data matrix can be obtained as follows:

[0032] (5)

[0033] The influence of Doppler filter characteristics can be introduced based on the specific frequency response characteristics of the filter; let the frequency response characteristics of the radar Doppler filter be... The updated data matrix is ​​then...

[0034] (6)

[0035] When Doppler filtering is directly implemented using the FFT algorithm, there is

[0036] (7)

[0037] in, The filter number where the target Doppler is located. The number of channels in the filter bank;

[0038] (8).

[0039] Another objective of this invention is to provide a radar target CPI echo simulation generation system based on precise electromagnetic calculation, comprising:

[0040] The determination module is used to determine the radar's operating parameters; based on the target's trajectory and the relative geometric position of the radar and the target, it determines the radar's central viewing angle. and the elevation angle of the observation center ;

[0041] The computing module is used to perform calculations within the radar's operating frequency band B. The center uses the frequency diversity method to calculate the complex RCS characteristic data of the target at different fixed frequencies at different times within the pulse.

[0042] The building block is used to apply the IFFT algorithm to invert and obtain the deterministic result. and A one-dimensional range profile of the radar target is obtained, and a broadband scattering characteristic database of the target is constructed accordingly.

[0043] The query module is used to calculate the number of pulses that can be accumulated in the CPI. Inside, with and Using the target broadband scattering characteristics as the center, query the target broadband scattering characteristics database to obtain the target's basic broadband scattering characteristics;

[0044] The module introduces the influence of target fluctuation characteristics, distinguishes different target types based on the Swerling target fluctuation model, and obtains the target scattering characteristic data matrix within the CPI; it also introduces the influence of antenna beam modulation effect and the influence of radar receiving and processing response characteristics.

[0045] Another object of the present invention is to provide a computer device including a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation.

[0046] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation.

[0047] Another objective of this invention is to provide an information data processing terminal for implementing the radar target CPI echo simulation generation system based on precise electromagnetic calculation.

[0048] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0049] First, this invention starts from the physical mechanism of target scattering. Based on commercial electromagnetic calculation software, it first obtains the all-round high-resolution one-dimensional range image feature data of a given target at a specific radar operating frequency. On this basis, based on the target heading and speed, target motion fluctuation model, actual radar range resolution, antenna beam pattern, signal processing method and other input parameters, through linear system analysis and processing model, it simulates and generates target coherent or non-coherent echo data within 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 of the echo generation process.

[0050] This invention proposes to obtain the omnidirectional broadband electromagnetic scattering characteristics of a target based on commercially available precise electromagnetic calculation software. Under given conditions such as target heading, speed, and radar parameters, the influence of antenna pattern modulation, target undulation model, Doppler effect, and signal processing response is introduced to simulate and generate a generalized radar target coherent or non-coherent CPI pulse group echo applicable to any radar parameters and target type. It can be applied to different targets and radar types and significantly improves the reliability of target echo simulation.

[0051] Second, the technical solution of this invention overcomes technical bias:

[0052] The technical solution of this invention effectively overcomes the problems of traditional radar target echo simulation, which cannot reflect the individual scattering characteristics of the target, cannot reflect the influence of the target's flight attitude, and cannot be applied to high-resolution radar and range-extended target scenarios. It obtains the target's omnidirectional broadband electromagnetic scattering characteristics through precise electromagnetic calculations. By introducing models of antenna beam modulation, range Doppler reception processing response, target fluctuation characteristics, etc., the system comprehensively reflects the spatial, temporal, and frequency characteristics, which is suitable for the application needs of high-fidelity simulation and high-precision simulation of radar echoes.

[0053] Third, the innovative points and progressiveness of the technical solution of this invention in industrial applications are summarized as follows:

[0054] 1. High-fidelity echo simulation achieved through precise electromagnetic calculations.

[0055] This invention provides a high-fidelity method for simulating and generating radar target CPI echoes, based on precise electromagnetic calculation methods and combined with the target's broadband scattering characteristics and radar operating parameters. By constructing a database of target broadband scattering characteristics and comprehensively considering target motion characteristics, fluctuation models, antenna beam modulation effects, and radar receiving and processing response characteristics, a comprehensive and accurate simulation of radar target echoes is achieved, filling the gaps in existing simulation methods for depicting real physical phenomena.

[0056] 2. Construction of a broadband scattering characteristic database

[0057] By employing frequency diversity within the radar's operating frequency band, complex RCS characteristics of the target at different frequencies and observation angles are calculated. An IFFT algorithm is then used to generate a one-dimensional range profile, constructing a comprehensive broadband target scattering characteristic database. This database is queried and applied within the CPI (Central Impact Model), providing fundamental data support for simulations. Compared to traditional methods, this significantly improves the efficiency and accuracy of target scattering characteristic calculations.

[0058] 3. Introduce accurate modeling of target fluctuation characteristics and motion effects.

[0059] This invention introduces a Swerling target undulation model to generate a target scattering characteristic data matrix within a CPI after distinguishing different target types. Furthermore, it incorporates the radial velocity of the target's motion to further refine the target scattering characteristic matrix. This step overcomes the shortcomings of existing technologies that fail to adequately consider the influence of target motion and undulation characteristics, enhancing the simulation method's adaptability to complex target scenarios.

[0060] 4. Simulation of Antenna Beam Modulation and Radar Receiver Response

[0061] By introducing the modulation effect of the antenna pattern and combining it with actual or simulated antenna main lobe pattern functions (such as Gaussian functions and cosine square functions), the intensity variation of the target echo signal at the antenna receiver is simulated. Simultaneously, the influence of radar receiving and processing characteristics on the target echo is considered, improving the realism of the simulation method from the perspective of the overall signal processing chain.

[0062] 5. Wide applicability and high computational efficiency

[0063] This invention encompasses target broadband scattering characteristic modeling, motion fluctuation impact analysis, and joint simulation of radar antenna and receiving characteristics, forming a complete CPI echo simulation method. Its core algorithm employs IFFT and matrix operations, achieving high computational efficiency and applicability to simulation needs of various radar systems and target types, while also being scalable to complex scenario simulations.

[0064] 6. Significant technological advancements in industrial applications

[0065] This method overcomes the shortcomings of existing technologies in simulation accuracy and physical realism. By performing multi-dimensional modeling of target and radar characteristics, it provides a precise simulation tool for radar design and performance evaluation. Especially in the fields of aerospace, defense, and high-resolution radar development, this method significantly improves the realism of target simulation scenarios and reduces system development and verification costs, demonstrating significant application value and promising prospects for widespread adoption.

[0066] In summary, this invention provides a novel approach to radar target echo simulation through precise electromagnetic calculations and systematic modeling, demonstrating significant technological advancements and industrial value. Attached Figure Description

[0067] Figure 1 This is a flowchart of a radar target CPI echo simulation generation method based on precise electromagnetic calculation provided in an embodiment of the present invention.

[0068] Figure 2 This is a block diagram of a radar target CPI echo simulation generation system based on precise electromagnetic calculation, provided in an embodiment of the present invention.

[0069] Figure 3 This is a schematic diagram of target coherent CPI pulse group echo data generation provided in an embodiment of the present invention.

[0070] Figure 4 This is a flowchart of the simulation algorithm provided in the embodiments of the present invention.

[0071] Figure 5 These are precise electromagnetic calculation geometric model diagrams of some typical ship targets provided in the embodiments of the present invention.

[0072] Figure 6 This is a one-dimensional high-resolution range image of an Arleigh Burke-class destroyer provided in an embodiment of the present invention.

[0073] Figure 7 This is a one-dimensional high-resolution distance image (26 meters long) of a civilian ship provided in an embodiment of the present invention.

[0074] Figure 8 This is the antenna pattern function diagram used for modeling provided in the embodiments of the present invention.

[0075] Figure 9 This is the CPI internal echo diagram provided in the embodiments of the present invention after considering the antenna beam scanning modulation effect.

[0076] Figure 10 This is the CPI internal echo map provided in the embodiment of the present invention after considering the inter-pulse fluctuation effect of the target.

[0077] Figure 11 This is a CPI target echo video image provided in an embodiment of the present invention.

[0078] Figure 12 This is a range-Doppler domain target echo map provided in an embodiment of the present invention.

[0079] Figure 13 This is a distance-dimensional echo processing response characteristic curve used in the modeling and simulation provided in this embodiment of the invention. Detailed Implementation

[0080] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0081] Specific industrial application examples:

[0082] Example 1: Verification of target characteristics by high-resolution radar

[0083] In the research 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 echo processing algorithms. This invention presents a target CPI echo simulation method based on precise electromagnetic calculations, which can provide realistic and accurate data support for generating radar echo signals from different targets. Specific application scenarios include:

[0084] 1. Verification of radar imaging accuracy

[0085] By constructing a broadband scattering characteristic database containing targets with different geometries 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.

[0086] 2. Target Feature Extraction Algorithm Testing

[0087] By combining the target's undulation characteristics and radial velocity effect, various complex echo data are generated to test the performance of the radar system's target feature extraction and target recognition algorithms under noise and interference conditions, thereby improving the reliability and robustness of the radar system.

[0088] Example 2: Radar Combat Simulation in Complex Scenarios

[0089] In the defense and military field, it is necessary to simulate and evaluate the performance of radar in complex combat scenarios. The CPI echo simulation method of this invention can be applied to simulation scenarios involving multiple targets and multiple motion states, generating high-fidelity target echo data. Specific application scenarios include:

[0090] 1. Multi-target tracking capability test of air defense radar

[0091] The echo characteristics of multiple targets at different altitudes, speeds, and azimuth angles are simulated to simulate complex echo data in real combat scenarios, which is used to test the performance of multi-target tracking and target threat priority ranking algorithms of air defense radar.

[0092] 2. Verification of radar jamming and anti-jamming capabilities

[0093] Antenna beam modulation and target fluctuation characteristics are incorporated into the simulation to generate target data with different echo characteristics, which are used to evaluate the radar's target detection and resolution capabilities under interference conditions, as well as the effectiveness of anti-jamming technologies.

[0094] Through these embodiments, the simulation method of the present invention provides a realistic and reliable simulation environment for radar research and development and verification, which not only improves the efficiency of system development, but also reduces the cost of actual testing, and has broad industrial application value.

[0095] like Figure 1 As shown, the radar target CPI echo simulation generation method based on precise electromagnetic calculation provided by this embodiment of the invention includes the following steps:

[0096] S101, Determine radar operating parameters;

[0097] S102, determine the radar center viewpoint based on the target's trajectory and the relative geometric position of the radar target. and the elevation angle of the observation center ;

[0098] S103, within the radar's operating frequency band B, is considered... The center uses the frequency diversity method to calculate the complex RCS characteristic data of the target at different fixed frequencies at different times within the pulse.

[0099] S104, using the IFFT algorithm, is determined through inversion. and A one-dimensional range profile of the radar target is obtained, and a broadband scattering characteristic database of the target is constructed accordingly.

[0100] S105, the number of pulses that can be accumulated in CPI Inside, with and Using the target broadband scattering characteristics as the center, query the target broadband scattering characteristics database to obtain the target's basic broadband scattering characteristics;

[0101] S106, Introducing the influence of target fluctuation characteristics, based on the Swerling target fluctuation model, different target types are distinguished to obtain the target scattering characteristic data matrix within CPI;

[0102] S107, introduces the influence of antenna beam modulation effect;

[0103] S108 introduces the impact of radar receiving and processing response characteristics.

[0104] The present invention provides the following methods for determining radar operating parameters:

[0105] Specifically, this includes: central operating frequency Polarization mode, operating bandwidth .

[0106] The target-based broadband scattering characteristics provided in this embodiment of the invention are denoted as... .

[0107] The target scattering characteristic data matrix within CPI provided in this embodiment of the invention:

[0108] ,in

[0109] , (1)

[0110] In the formula, A sequence of random variables that meets the fluctuation characteristics and random distribution features specified by the Swerling model;

[0111] right The data matrix incorporates the influence of the target's radial velocity, resulting in the new correction matrix:

[0112] (2).

[0113] The impact of introducing antenna beam modulation effect provided in the embodiments of the present invention:

[0114] (3)

[0115] In the formula, This is the antenna single-pass radiation pattern function. It can be simulated using the measured radar antenna radiation pattern or based on the classic radar antenna main lobe radiation pattern function. Typical antenna main lobe radiation pattern simulation functions include the Gaussian function and the cosine square function.

[0116] The impact of introducing radar receiver processing response characteristics provided in the embodiments of the present invention:

[0117] For data matrix The influence of filtering in the range and Doppler domains is introduced. Since pulse compression has already been considered in the one-dimensional range image generation process, only the influence of pulse envelope reception processing needs to be considered in the range dimension. For simple pulses, the ambiguity function is...

[0118] (4)

[0119] In the formula, The pulse width. For time delay, This is the frequency shift difference;

[0120] For a single pulse, considering the effect of receiver matched filtering, the corrected echo data matrix can be obtained as follows:

[0121] (5)

[0122] The influence of Doppler filter characteristics can be introduced based on the specific frequency response characteristics of the filter; let the frequency response characteristics of the radar Doppler filter be... The updated data matrix is ​​then...

[0123] (6)

[0124] When Doppler filtering is directly implemented using the FFT algorithm, there is

[0125] (7)

[0126] in, The filter number where the target Doppler is located. The number of channels in the filter bank;

[0127] (8).

[0128] like Figure 2 As shown, an embodiment of the present invention provides a radar target CPI echo simulation generation system based on precise electromagnetic calculation, comprising:

[0129] The determination module is used to determine the radar's operating parameters; based on the target's trajectory and the relative geometric position of the radar and the target, it determines the radar's central viewing angle. and the elevation angle of the observation center ;

[0130] The computing module is used to perform calculations within the radar's operating frequency band B. The center uses the frequency diversity method to calculate the complex RCS characteristic data of the target at different fixed frequencies at different times within the pulse.

[0131] The building block is used to apply the IFFT algorithm to invert and obtain the deterministic result. and A one-dimensional range profile of the radar target is obtained, and a broadband scattering characteristic database of the target is constructed accordingly.

[0132] The query module is used to calculate the number of pulses that can be accumulated in the CPI. Inside, with and Using the target broadband scattering characteristics as the center, query the target broadband scattering characteristics database to obtain the target's basic broadband scattering characteristics;

[0133] The module introduces the influence of target fluctuation characteristics, distinguishes different target types based on the Swerling target fluctuation model, and obtains the target scattering characteristic data matrix within the CPI; it also introduces the influence of antenna beam modulation effect and the influence of radar receiving and processing response characteristics.

[0134] Another object of the present invention is to provide a computer device including a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation.

[0135] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation.

[0136] Another objective of this invention is to provide an information data processing terminal for implementing the radar target CPI echo simulation generation system based on precise electromagnetic calculation.

[0137] Specific implementation of the present invention:

[0138] 1. Given the target's geometric model, electrical characteristic model, and parameters such as radar operating frequency, viewing angle, and polarization, the aforementioned software can quickly and easily obtain static electromagnetic scattering characteristic data of complex targets. Based on this, by introducing the influence of relevant system factors such as target motion Doppler frequency shift, radar resolution element parameters, antenna modulation effect, target fluctuations, and receiver processing channel response, the scattering characteristic data of the target's dynamic echo within the CPI can be easily obtained. The target coherent pulse group echo generation process based on precise electromagnetic calculation is as follows: Figure 3 As shown.

[0139] First, for a specific radar system, broadband one-dimensional range profiles of typical targets under different attitudes and perspectives are accurately calculated in CST or FEKO to establish a high-resolution static scattering characteristic database of the target. Based on this, considering the influence of factors such as target RCS fluctuations within the CPI, antenna pattern modulation, receiver processing response, and Doppler processing, the original electromagnetic calculation data is progressively corrected to finally obtain the target's coherent pulse group echo data within the CPI. The specific implementation algorithm and simulation steps are described below:

[0140] (1) Determine the radar operating parameters, specifically including: center operating frequency Polarization mode, operating bandwidth ;

[0141] (2) Determine the radar center angle based on the target's trajectory and the relative geometric position of the radar target. and the elevation angle of the observation center ;

[0142] (3) Within the radar operating frequency band B, it is assumed that... The center uses the frequency diversity method to calculate the complex RCS characteristic data of the target at different fixed frequencies at different times within the pulse.

[0143] (4) Using the IFFT algorithm, the determination is obtained by inversion. and A one-dimensional range profile of the radar target is obtained, and a broadband scattering characteristic database of the target is constructed accordingly.

[0144] (5) The number of pulses that can be accumulated in CPI Inside, with and Centered on the target, the target's basic broadband scattering characteristics are obtained by querying the target broadband scattering characteristics database, denoted as . ;

[0145] (6) Introducing the influence of target fluctuation characteristics, based on the Swerling target fluctuation model, different target types are distinguished to obtain the target scattering characteristic data matrix within CPI. ,in

[0146] , (1)

[0147] In the formula, A sequence of random variables that satisfies the fluctuation characteristics and random distribution features specified by the Swerling model.

[0148] (6) The data matrix incorporates the influence of the target's radial velocity, resulting in the new correction matrix:

[0149] (2)

[0150] (7) The influence of introducing antenna beam modulation effect

[0151] (3)

[0152] In the formula, This is the antenna single-pass radiation pattern function. It can be simulated using the measured radar antenna radiation pattern or 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.

[0153] (8) The impact of introducing radar receiver processing response characteristics

[0154] For data matrix The effects of filtering in the range and Doppler domains are introduced. Since pulse compression has already been considered in the one-dimensional range image generation process, only the effects of pulse envelope reception processing need to be considered in the range dimension. For a simple pulse, its ambiguity function is...

[0155] (4)

[0156] In the formula, The pulse width. For time delay, This is the frequency shift difference.

[0157] For a single pulse, considering the effect of receiver matched filtering, the corrected echo data matrix can be obtained as follows:

[0158] (5)

[0159] The influence of Doppler filter characteristics can be introduced based on the specific frequency response characteristics of the filter. Let the frequency response characteristics of the radar Doppler filter be denoted as... The updated data matrix is ​​then...

[0160] (6)

[0161] When Doppler filtering is directly implemented using the FFT algorithm, there is

[0162] (7)

[0163] in, The filter number where the target Doppler is located. This represents the number of channels in the filter bank.

[0164] (8)

[0165] The algorithm flow for CPI pulse group echo simulation generation based on target broadband scattering characteristics is as follows: Figure 4 As shown.

[0166] I. Specific application areas or related products of this invention.

[0167] This invention is mainly applied in the development process of equipment and systems such as radar training simulators, radar signal simulators, and radar data simulators. It is used as a dedicated software functional module or system functional component to generate high-precision and high-fidelity radar echo signal simulations.

[0168] II. Evidence related to the technical effects obtained by the embodiments of the present invention.

[0169] To demonstrate the technical effectiveness of the embodiments of the present invention, the application effect of the embodiments of the present invention will be specifically explained using the simulation process of S-band radar echo signals of a typical ship target as an example.

[0170] Figure 5The image shows geometric model images of several typical simulated ship targets during the experiment. The radar center frequency was set to 3 GHz, and horizontal polarization was used. The relevant ships were modeled and calculated using the CST electromagnetic calculation software with a bandwidth of 300 MHz to obtain one-dimensional high-resolution complex range images of the targets (range resolution 0.5 meters), thereby acquiring a database of the targets' all-aspect, all-elevation broadband scattering characteristics. Figure 5 Taking targets (2) and (7) as examples, the obtained one-dimensional high-resolution range images are shown in the figures below. Figure 6 and Figure 7 The design primarily considers the application scenarios of shore-based and shipborne radar detecting distant targets, and sets the sweep angle to 0°.

[0171] A one-dimensional linear array antenna radiation pattern model is used as the antenna radiation pattern function, and Hanning window weighting is used to suppress sidelobes to obtain the simulated antenna radiation pattern. Figure 8 The image shows the simulated radiation pattern of a radar antenna, assuming that the number of transmitted and received pulses within the 3dB beamwidth of the radar antenna is 10.

[0172] The echo image (under high resolution) of multiple pulses after antenna beam scanning modulation is shown below. Figure 9 As shown, the number of echo pulses within the CPI is set to 41.

[0173] Based on this, the influence of inter-pulse target echo amplitude fluctuations is further considered, and a fluctuation factor is set. This is to reflect the impact of RCS fluctuations on radar echo amplitude. Taking the above two types of targets under an incident azimuth angle of 30° as an example, the processed results are as follows: Figure 10 As shown in the figure, the model successfully incorporates the variation in echo scattering intensity caused by changes in target attitude between pulses, and the attenuation of echo fluctuations between different pulses meets the randomness requirement.

[0174] Continuing to consider the impact of target radial motion on Doppler frequency shift and the response characteristics of the radar receiving and processing system, ambiguity functions are introduced in the range dimension to slice the range dimension data, performing down-resolution processing to match the operating characteristics of the radar system under analysis. This yields the final radar target CPI pulse group echo image, as shown below. Figure 11 As shown. Figure 12 The image shown is the corresponding range-Doppler echo image (with the effects of Doppler filtering already incorporated), where the target's radial velocity is set to 9 m / s, and the radar signal is a simple rectangular pulse (its range-Doppler echo processing response curve is shown in Figure 1). Figure 13 As shown in the figure, the pulse width is 0.1µs and the repetition period is 1ms. All relevant parameters can be flexibly set according to the actual radar operating parameters.

[0175] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or by software executed by various types of processors, or by a combination of the above-described hardware circuitry and software, such as firmware.

[0176] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for simulating and generating radar target CPI echoes based on precise electromagnetic calculations, characterized in that, The radar target CPI echo simulation generation method based on precise electromagnetic calculation includes the following steps: Step 1: Determine the radar operating parameters; Step 2: Determine the radar center viewpoint based on the target's trajectory and the relative geometric position of the radar target. and the elevation angle of the observation center Step 3: Within the radar operating frequency band B, with f0 as the center, use the frequency diversity method to calculate the complex RCS characteristic data of the target at different fixed frequencies at different times within the pulse. Step 4: Use the IFFT algorithm to invert and obtain the determination. and A one-dimensional range profile of the radar target is obtained, and a broadband scattering characteristic database of the target is constructed accordingly. Step 5, the number of pulses N that can be accumulated in CPI CPI Inside, with and Using the target broadband scattering characteristics as the center, query the target broadband scattering characteristics database to obtain the target's basic broadband scattering characteristics; Step 6: Introduce the influence of target fluctuation characteristics. Based on the Swerling target fluctuation model, distinguish different target types and obtain the target scattering characteristic data matrix within the CPI. Step 7, introduce the influence of antenna beam modulation effect; Step 8: Introduce the impact of radar receiver processing response characteristics; The effect of introducing antenna beam modulation effect: In the formula, G(θ) is the antenna single-pass pattern function, which can be simulated using the measured radar antenna pattern or based on the classic radar antenna main lobe pattern function. Typical antenna main lobe pattern simulation functions include the Gaussian function and the cosine square function. The impact of introducing radar receiver processing response characteristics: For data matrix The influence of filtering is introduced in the range and Doppler domains. Since pulse compression has already been considered in the one-dimensional range image generation process, only the influence of pulse envelope reception processing needs to be considered in the range dimension. For simple pulses, the ambiguity function is... In the formula, t p Let τ be the pulse width, τ be the time delay, and ξ be the frequency shift difference; For a single pulse, considering the effect of receiver matched filtering, the corrected echo data matrix can be obtained as follows: The influence of Doppler filter characteristics can be introduced based on the specific frequency response characteristics of the filter; let the frequency response characteristics of the radar Doppler filter be H(f d If ), then the updated data matrix is When Doppler filtering is directly implemented using the FFT algorithm, there is Where m is the filter number where the target Doppler is located, and M is the number of channels in the filter bank; 2. The radar target CPI echo simulation generation method based on precise electromagnetic calculation as described in claim 1, characterized in that, The radar operating parameters are determined as follows: Specifically, this includes: center operating frequency f0, polarization mode, and operating bandwidth B.

3. The radar target CPI echo simulation generation method based on precise electromagnetic calculation as described in claim 1, characterized in that, The target's basic broadband scattering characteristics are denoted as g = {g n |n=1,2,…,N range } 4. The radar target CPI echo simulation generation method based on precise electromagnetic calculation as described in claim 1, characterized in that, The target scattering characteristic data matrix within the CPI: in In the formula, {a m A sequence of random variables that satisfies the fluctuation characteristics and random distribution features specified by the Swerling model; right The data matrix incorporates the influence of the target's radial velocity, resulting in the new correction matrix:

5. A radar target CPI echo simulation generation system based on precise electromagnetic calculation, implementing the radar target CPI echo simulation generation method based on precise electromagnetic calculation as described in any one of claims 1-4, characterized in that, The radar target CPI echo simulation generation system based on precise electromagnetic calculation includes: The determination module is used to determine the radar's operating parameters; based on the target's trajectory and the relative geometric position of the radar and the target, it determines the radar's central viewing angle. and the elevation angle of the observation center The calculation module is used to calculate the complex RCS characteristic data of the target at different times and at different fixed frequencies within the radar operating frequency band B, with f0 as the center, using the frequency diversity method. The building block is used to apply the IFFT algorithm to invert and obtain the deterministic result. and A one-dimensional range profile of the radar target is obtained, and a broadband scattering characteristic database of the target is constructed accordingly. The query module is used to calculate the number of pulses N that can be accumulated in the CPI. CPI Inside, with and Using the target broadband scattering characteristics as the center, query the target broadband scattering characteristics database to obtain the target's basic broadband scattering characteristics; The module introduces the influence of target fluctuation characteristics, distinguishes different target types based on the Swerling target fluctuation model, and obtains the target scattering characteristic data matrix within the CPI; it also introduces the influence of antenna beam modulation effect and the influence of radar receiving and processing response characteristics.

6. A computer device, characterized in that, The computer device includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation as described in any one of claims 1-4.

7. A computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the radar target CPI echo simulation generation method based on precise electromagnetic calculation as described in any one of claims 1-4.

8. 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 5.

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