Echo simulation method based on electromagnetic scattering model
By constructing a three-dimensional model of the target and calculating its electromagnetic scattering characteristics using an echo simulation method based on an electromagnetic scattering model, the problem of insufficient simplification and scalability of radar echo simulation models in existing technologies is solved, and accurate simulation and efficient testing of the target's electromagnetic characteristics are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-26
- Publication Date
- 2026-04-10
AI Technical Summary
Existing radar echo simulation technology suffers from oversimplification of models, insufficient scalability, and poor repeatability. It cannot realistically simulate the electromagnetic characteristics of targets, resulting in high testing costs, low efficiency, and poor safety, and thus cannot meet the testing requirements of modern radar.
An echo simulation method based on an electromagnetic scattering model is adopted. By constructing a three-dimensional model of the target, establishing an electromagnetic measurement coordinate system, calculating the electromagnetic scattering characteristics, generating an electromagnetic scattering characteristic file, and combining the target's motion trajectory and attitude information, the electromagnetic scattering characteristics of the target are simulated in real time, generating multi-channel, multi-target signals, and accurately simulating radar echo characteristics.
It achieves accurate simulation of the electromagnetic scattering characteristics of the target, ensuring the authenticity and repeatability of the radar echo, reducing testing costs, improving testing efficiency, and supporting the reliability and comprehensiveness of target detection, tracking, and identification tasks.
Smart Images
Figure CN121831707A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of radar testing technology, specifically relating to an electromagnetic characteristic simulation echo signal technology. Background Technology
[0002] In the design, development, production, evaluation, and assessment of radar systems, efficient and low-cost testing methods are playing an increasingly important role in radar system verification, algorithm validation, phase transition control, and performance evaluation.
[0003] Traditional practical testing methods suffer from high costs, long time consumption, low efficiency, poor safety, and simple, non-repeatable test scenarios, which cannot meet the testing requirements of modern radar.
[0004] Radar echo virtual simulation technology is an efficient testing and verification method with the potential application in radar development. However, a common problem in simulation verification is insufficient realism. In particular, simulating the electromagnetic characteristics of targets has a significant impact on target detection, tracking, and identification.
[0005] Current echo simulation methods suffer from problems such as oversimplification of models, insufficient scalability, and poor repeatability. How to model and simulate the true electromagnetic characteristics of a target, and conduct reliable, repeatable, low-cost, rapid, and comprehensive experimental analysis and evaluation of radar performance and effectiveness, is an urgent problem to be solved. Summary of the Invention
[0006] To address the technical problems of insufficient simulation of target electromagnetic scattering characteristics, overly simplistic electromagnetic scattering models, poor scalability, and lack of repeatability in radar echo signal level simulation, this invention adopts an echo simulation method based on an electromagnetic scattering model. Based on the target's motion trajectory and attitude information, the radar cross section (RCS) of the target at various moments along the trajectory is calculated, achieving accurate simulation of the target's electromagnetic scattering characteristics and providing a reliable basis for performance testing and verification of various radar detection, tracking, and identification tasks.
[0007] Based on the target's external dimensions, a three-dimensional model of the target is constructed, an electromagnetic measurement coordinate system for the target is established, elevation and horizontal observation planes are selected, the three-dimensional model of the target is imported into the electromagnetic scattering characteristic simulation software, the three-dimensional model is meshed, the electromagnetic scattering characteristics are calculated, the electromagnetic scattering characteristic file of the target is generated, and the electromagnetic scattering characteristic model of the target is constructed.
[0008] Furthermore, taking the target centroid as the origin and the vertical axis as... The axis, pointing towards the front end as the positive direction, and the longitudinal plane of symmetry as... The axis and the direction pointing upwards are taken as the positive direction, and are determined according to the right-hand rule. Establish the target electromagnetic measurement coordinate system along the positive direction of the axis. .
[0009] Furthermore, the electromagnetic measurement coordinate system is selected. The plane serves as the elevation observation plane. The positive axis direction is taken as 0 degrees of pitch. The positive axis direction is taken as 90 degrees of pitch. The negative axis direction is taken as pitch -90 degrees; an electromagnetic measurement coordinate system is selected. The plane is used as the azimuth observation plane. The positive direction of the axis is taken as 0 degrees for the azimuth. The positive direction of the axis is taken as 90 degrees for azimuth. The negative direction of the axis is taken as 180 degrees for orientation. The negative direction of the axis is taken as 270 degrees.
[0010] Based on the symmetry characteristics of the targets, they are divided into rotationally symmetric targets and non-rotationally symmetric targets. The electromagnetic scattering characteristics of the targets are calculated at specific frequency points from different elevation angles and azimuth angles, generating two-dimensional observation electromagnetic scattering characteristic data of rotationally symmetric targets and non-rotationally symmetric targets, and simulating the electromagnetic scattering characteristics of rotationally symmetric targets and non-rotationally symmetric targets.
[0011] Furthermore, the rotationally symmetric target along any vertical axis The RCS of the target observed from different azimuth angles on the cross section containing the axis is consistent. Only the electromagnetic scattering characteristics data at a 0-degree elevation angle on one side and at different azimuth angles are calculated, i.e., consistent with... The system generates electromagnetic scattering characteristic data at different azimuth angles, saving computer resources; it also calculates electromagnetic scattering characteristic data at different elevation and azimuth angles for non-rotationally symmetric targets.
[0012] Determine the radar coordinates (latitude, longitude, altitude, LBH), and the target's coordinates in the Earth-centered Earth-fixed coordinate system. Location ,speed Establish a station-centered coordinate system with the radar as the origin, i.e., the North-East coordinate system. Calculate the target's velocity vector in the station-centered coordinate system; assuming the radar's beam pointing azimuth angle A degrees and elevation angle E degrees at the current moment, calculate the unit vector of the radar beam pointing in the station-centered coordinate system; taking the target axis pointing towards the target's motion direction as the velocity direction, calculate the angle between the beam pointing and the target axis, query the target's electromagnetic scattering characteristic data based on the angle, interpolate to the current angle, calculate the electromagnetic scattering amplitude value at the current moment, and simulate the electromagnetic scattering characteristics of the rotationally symmetric target in real time.
[0013] Given the radar's beam pointing azimuth angle A degrees and elevation angle E degrees at the current moment, calculate the unit vector of the radar beam pointing; based on the transformation relationship between the orbital coordinate system, target coordinate system, and electromagnetic measurement coordinate system, calculate the electromagnetic measurement coordinate system. Vector representation of the three coordinate axes; select the opposite direction vector of the beam pointing, and calculate its angle with each coordinate axis of the electromagnetic measurement coordinate system. Then the target observation vector of the electromagnetic measurement coordinate system for The observed azimuth angle is The observed pitch angle is The system queries the target electromagnetic scattering amplitude value at the current moment and simulates the electromagnetic scattering characteristics of a non-rotationally symmetric target in real time.
[0014] Based on the real-time simulation process of the target's electromagnetic characteristics, the RCS of the target at any time is calculated, and the echo amplitude variation characteristics of the target are accurately simulated according to the radar equation. Based on the transmission characteristics of electromagnetic waves, the position information of the target in the radar echo is calculated. According to the current radar operating mode, the corresponding baseband digital echo signal is generated to simulate the target echo in detail.
[0015] Furthermore, range delay, Doppler modulation, and beam modulation are added to the echo signal to form a multi-channel, multi-target signal; the target signal and noise signal are aligned and superimposed according to the range gate sampling points to synthesize digital sampled echo signals of different beam channels; the multi-channel echo signals are allocated, reconstructed, arranged, and packaged into multi-channel fiber optic data and sent to the radar signal processing system for various functional performance tests and verifications.
[0016] Existing technologies are based on relatively simple fluctuation models and are suitable for target echoes whose RCS probability distribution conforms to the fluctuation model. However, they cannot accurately simulate the real RCS change process of the target, nor are they suitable for the RCS of the target at a specific angle, and therefore cannot ensure the realism of the simulation.
[0017] This invention establishes a complete simulation process from electromagnetic scattering model to real-time RCS calculation to echo generation based on the motion process of a real target. Existing technologies do not involve the process from electron scattering model to real-time RCS calculation of the target.
[0018] This invention takes into account the target's attitude changes, micro-motion characteristics, and shape characteristics, and classifies the target into rotationally symmetric targets and non-rotationally symmetric targets. Different electromagnetic scattering characteristic calculation methods are used for different shape characteristics, which can realistically simulate the target's RCS changes, while reducing the amount of calculation and ensuring the real-time performance and reliability of the calculation.
[0019] This invention enables accurate simulation of the electromagnetic scattering characteristics of a target and realistic simulation of the radar echo fluctuations of a target during its motion. It is of great significance for target detection, tracking, and identification, and allows for real, reliable, repeatable, low-cost, rapid, comprehensive testing, analysis, and evaluation of various radar performance, effectiveness, and baseline data. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of a symmetrical target coordinate system.
[0021] Figure 2 This is a schematic diagram of an asymmetric target coordinate system.
[0022] Figure 3 This is a schematic diagram of radar echo simulation. Detailed Implementation
[0023] The technical solution for simulating target echoes is explained in detail below with reference to the accompanying drawings.
[0024] Constructing a target electromagnetic scattering characteristic model: Based on the target's external dimensions, construct a three-dimensional model of the target; establish a target electromagnetic measurement coordinate system. With the target centroid as the origin and the vertical axis as... The axis, pointing towards the front end as the positive direction, and the longitudinal plane of symmetry as... The axis and the direction pointing upwards are taken as the positive direction, and are determined according to the right-hand rule. The positive direction of the axis; import the target's 3D model into electromagnetic scattering characteristic simulation software such as FEKO; mesh the 3D model, calculate the electromagnetic scattering characteristics, and generate the target's electromagnetic scattering characteristic file.
[0025] Selecting the electromagnetic measurement coordinate system The plane serves as the elevation observation plane. The positive axis direction is taken as 0 degrees of pitch. The positive axis direction is taken as 90 degrees of pitch. The negative axis direction is taken as pitch -90 degrees; an electromagnetic measurement coordinate system is selected. The plane is used as the azimuth observation plane. The positive direction of the axis is taken as 0 degrees for the azimuth. The positive direction of the axis is taken as 90 degrees for azimuth. The negative direction of the axis is taken as 180 degrees for orientation. The negative direction of the axis is taken as 270 degrees.
[0026] The electromagnetic scattering characteristics of a target are calculated at specific frequencies from different elevation and azimuth angles, generating two-dimensional observational electromagnetic scattering characteristic data of the target. Based on the target's symmetry characteristics, it is divided into rotationally symmetric targets and non-rotationally symmetric targets. Rotationally symmetric targets are categorized along any vertical axis. The RCS of the target observed from different azimuth angles on the cross section containing the axis is consistent. Only the electromagnetic scattering characteristics data at a 0-degree elevation angle on one side and at different azimuth angles are calculated, i.e., consistent with... The system generates electromagnetic scattering characteristic data at different azimuth angles, saving computer resources; it also calculates electromagnetic scattering characteristic data at different elevation and azimuth angles for non-rotationally symmetric targets.
[0027] Simulation of electromagnetic scattering characteristics of a rotationally symmetric target: Determine radar coordinates (latitude, longitude, and altitude, LBH), and the target's position in a geocentric coordinate system. Location ,speed Establish a station-centered coordinate system with the radar as the origin, i.e., the North-East coordinate system. Calculate the target's velocity vector in the station-centered coordinate system; assuming the radar's beam pointing azimuth angle A degrees and elevation angle E degrees at the current moment, calculate the unit vector of the radar beam pointing in the station-centered coordinate system; taking the target axis pointing towards the target's motion direction as the velocity direction, calculate the angle between the beam pointing and the target axis, query the target's electromagnetic scattering characteristic data based on the angle, interpolate to the current angle, and calculate the electromagnetic scattering amplitude value at the current moment. For symmetrical targets, such as... Figure 1 As shown.
[0028] Real-time radar control information and target motion characteristics are extracted based on the echo signal. Let RadarLBH be the current radar station location in the latitude-longitude coordinate system, and the target location be in the Earth-centered coordinate system. ,speed The radar beam is pointing at the target at the current moment, with an azimuth angle of A degrees and an elevation angle of E degrees.
[0029] The position of the target in the Earth-centered, Earth-fixed coordinate system is determined based on the target's kinematic equations. Convert to a station-centered coordinate system with the radar station site as the origin. Location The speed of the target velocity converted to station-centered coordinate system .
[0030] Since the target axis points towards the target's motion direction as the velocity direction, the angle between the beam pointing vector and the target axis is calculated based on the angle between the beam pointing vector and the velocity pointing vector. Then, the target's electromagnetic scattering characteristic data is retrieved based on this angle, and an interpolation algorithm is used to calculate the electromagnetic scattering cross-section at the current moment. .
[0031] Simulate the electromagnetic scattering characteristics of a non-rotationally symmetric target: Assume the radar beam pointing azimuth angle A degrees and elevation angle E degrees at the current moment, calculate the unit vector of the radar beam pointing; based on the transformation relationship between the orbital coordinate system, the target coordinate system, and the electromagnetic measurement coordinate system, calculate the electromagnetic measurement coordinate system. Vector representation of the three coordinate axes; select the opposite direction vector of the beam pointing, and calculate its angle with each coordinate axis of the electromagnetic measurement coordinate system. Then the target observation vector of the electromagnetic measurement coordinate system for The observed azimuth angle is The observed pitch angle is Asymmetric targets such as Figure 2 As shown.
[0032] Refined Target Echo Simulation: Based on the real-time simulation process of the target's electromagnetic characteristics, the RCS of the target at any given time is calculated, and the echo amplitude variation characteristics of the target are accurately simulated according to the radar equations. Based on the transmission characteristics of electromagnetic waves, the position information of the target in the radar echo is calculated. According to the current radar operating mode, the corresponding baseband digital echo signal is generated, and range delay, Doppler modulation, and beam modulation are added to form a multi-channel, multi-target signal. The target signal and noise signal are aligned and superimposed according to the range gate sampling points to synthesize digital sampled echo signals of different beam channels. The multi-channel echo signals are allocated, reconstructed, arranged, and packaged into multi-channel fiber optic data and sent to the radar signal processing system for various functional performance tests and verifications.
[0033] Let R be the distance between the target and the radar, and Cv be the speed of light. The radar emits two pulse excitation signals, which, upon encountering the target, are reflected back to the radar. After a time interval of 2R / Cv, the target echo signal is received. Figure 3 As shown, the echo amplitude is inversely proportional to the fourth power of the distance R. The pulse width, bandwidth, and frequency modulation type of the echo are consistent with the excitation signal, according to the radar equation. Calculate the signal-to-noise ratio of the target, where For radar transmission power, For transmit gain, For receiving gain, For wavelength, Boltzmann constant, For bandwidth, Noise figure For system losses, At standard room temperature, the Doppler modulation coefficient of the echo is calculated based on the target's velocity relative to the radar. Based on the target's position, amplitude, Doppler modulation coefficient, and transmitted waveform, a precise echo signal of the target is generated.
[0034] The above are embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention are included within the protection scope of the present invention.
Claims
1. A method for echo simulation based on an electromagnetic scattering model, characterized in that, The application relates to a method for simulating a target echo, and belongs to the field of radar simulation. According to the shape size information of the target, a three-dimensional model of the target is constructed, a target electromagnetic measurement coordinate system is established, a pitching and horizontal observation plane is selected, the three-dimensional model of the target is imported into electromagnetic scattering characteristic simulation software, the three-dimensional model is meshed, electromagnetic scattering characteristics are calculated, an electromagnetic scattering characteristic file of the target is generated, and an electromagnetic scattering characteristic model of the target is constructed; according to the symmetry characteristics of the target, the target is divided into a rotationally symmetric target and a non-rotationally symmetric target, electromagnetic scattering characteristics of the target are calculated from different pitching angles and azimuth angles at a specific frequency point, two-dimensional observation electromagnetic scattering characteristic data of the rotationally symmetric target and the non-rotationally symmetric target are generated, and electromagnetic scattering characteristics of the rotationally symmetric target and the non-rotationally symmetric target are simulated; according to a target electromagnetic characteristic real-time simulation process, scattering cross-sectional area RCS of the target at any moment is calculated, echo amplitude variation characteristics of the target are accurately simulated according to a radar equation, position information of the target in a radar echo is calculated according to transmission characteristics of electromagnetic waves, corresponding baseband digital echo signals are generated according to a current radar working mode, and the target echo is finely simulated.
2. The electromagnetic scattering model based echo simulation method of claim 1, wherein, The target electromagnetic measurement coordinate system is established, including: taking the target mass center as the origin, the longitudinal axis as the axis, pointing to the front end as the positive direction, the longitudinal symmetry plane as the axis, pointing to the top as the positive direction, determining the positive direction of the axis according to the right-hand rule, and establishing the target electromagnetic measurement coordinate system . 3. The electromagnetic scattering model based echo simulation method of claim 2, wherein, The selection of the elevation and horizontal observation planes includes: selecting the electromagnetic measurement coordinate system. The plane serves as the elevation observation plane. The positive axis direction is taken as 0 degrees of pitch. The positive axis direction is taken as 90 degrees of pitch. The negative axis direction is taken as pitch -90 degrees; an electromagnetic measurement coordinate system is selected. The plane is used as the azimuth observation plane. The positive direction of the axis is taken as 0 degrees for the azimuth. The positive direction of the axis is taken as 90 degrees for azimuth. The negative direction of the axis is taken as 180 degrees for orientation. The negative direction of the axis is taken as 270 degrees.
4. The electromagnetic scattering model based echo simulation method of claim 1, wherein, The method comprises the following steps: calculating electromagnetic scattering characteristics of the target, wherein the target is a rotationally symmetric target or a non-rotationally symmetric target The scattering cross section area RCS of the target observed from different azimuth angles on the cross section where the axis is located is consistent, and only the electromagnetic scattering characteristic data of one side with a pitch angle of 0 degrees and different azimuth angles is calculated, that is, the electromagnetic scattering characteristic data of the target observed from different azimuth angles on the cross section where the axis is located is consistent, and only the electromagnetic scattering characteristic data of one side with a pitch angle of 0 degrees and different azimuth angles is calculated The scattering cross section area RCS of the target observed from different azimuth angles on the cross section where the axis is located is consistent, and only the electromagnetic scattering characteristic data of one side with a pitch angle of 0 degrees and different azimuth angles is calculated, that is, the electromagnetic scattering characteristic data of the target observed from different azimuth angles on the cross section where the axis is located is consistent, and only the electromagnetic scattering characteristic data of one side with a pitch angle of 0 degrees and different azimuth angles is calculated 5. The electromagnetic scattering model based echo simulation method of claim 4, wherein, The electromagnetic scattering characteristics of the simulated rotationally symmetric target include: determining the radar coordinates (latitude, longitude, and altitude, LBH), and the target's position in the Earth-centered Earth-fixed coordinate system. Location ,speed Establish a station-centered coordinate system with the radar as the origin, i.e., the North-East coordinate system. Calculate the velocity vector of the target in the station center coordinate system; assuming the azimuth angle A degrees and elevation angle E degrees of the radar beam pointing at the current moment, calculate the unit vector of the radar beam pointing in the station center coordinate system; taking the target axis pointing to the target motion direction as the velocity direction, calculate the angle between the beam pointing and the target axis, query the target electromagnetic scattering characteristic data based on the angle, interpolate to the current angle, and calculate the electromagnetic scattering amplitude value at the current moment.
6. The electromagnetic scattering model based echo simulation method of claim 5, wherein, The electromagnetic scattering characteristics of the simulated rotationally symmetric target include: assuming the radar's current location is in a latitude-longitude coordinate system (RadarLBH), and the radar's beam is currently pointing directly at the target, the target's position in a geocentric coordinate system is determined based on the target's kinematic equations. Convert to a station-centered coordinate system with the radar station site as the origin. Location The speed of the target velocity converted to station-centered coordinate system Based on the angle between the beam pointing vector and the velocity pointing vector, the angle between the beam pointing direction and the target axis is calculated. Using this angle, the target's electromagnetic scattering characteristic data is retrieved, and an interpolation algorithm is employed to calculate the electromagnetic scattering cross-section at the current moment. .
7. The electromagnetic scattering model based echo simulation method of claim 4, wherein, The simulation of electromagnetic scattering characteristics of the non-rotationally symmetric target comprises: setting a radar beam pointing azimuth angle A degrees and elevation angle E degrees at a current time, calculating a unit vector of the radar beam pointing; according to a conversion relationship among an orbit coordinate system, a target coordinate system and an electromagnetic measurement coordinate system, calculating a target observation vector of the electromagnetic measurement coordinate system Vector representation of three coordinate axes; selecting a reverse direction vector of the beam pointing, calculating an included angle between the reverse direction vector and each coordinate axis of the electromagnetic measurement coordinate system , and querying a target electromagnetic scattering amplitude value at the current time. 8. The electromagnetic scattering model based echo simulation method of claim 1, wherein, The fine simulation of the target echo comprises the following steps: distance delay, Doppler modulation and beam modulation are added to the echo signal to form a multi-channel and multi-target signal; the target signal and a noise signal are aligned and superposed according to distance gate sampling points to synthesize digital sampling echo signals of different beam channels; and the multi-channel echo signal is distributed, reconstructed, arranged and packed into multi-channel optical fiber data, which is sent to a radar signal processing system for various functional performance tests and verifications.
9. The electromagnetic scattering model based echo simulation method of claim 8, wherein, The fine simulation target echo includes: R is the distance between the target and the radar, Cv is the speed of light, the radar transmits two pulse excitation signals, meets the target, reflects back to the radar, and receives the target echo signal after 2R / Cv time, the echo amplitude is inversely proportional to the fourth power of the distance R, the echo pulse width, bandwidth and frequency modulation type are consistent with the excitation signal, according to the radar equation Calculate the signal-to-noise ratio of the target, wherein P is the radar transmitting power, Gt is the transmitting gain, Gr is the receiving gain, λ is the wavelength, K is the Boltzmann constant, B is the bandwidth, η is the noise coefficient, Ls is the system loss, T is the standard room temperature, and the Doppler modulation coefficient of the echo is calculated according to the speed of the target relative to the radar According to the position, amplitude, Doppler modulation coefficient and transmitting waveform of the target, the accurate echo signal of the target is generated.