Method for simulating tracks of two radars

Abstract

The invention discloses a method for simulating tracks of two radars, which comprises the following steps of: carrying simulation equipment by using an unmanned aerial vehicle, calculating echo simulation parameters according to preset simulation track information, simulation track sampling points of the two radars and motion control information of the unmanned aerial vehicle and according to a relationship among the simulation track sampling points, the radars and the simulation equipment; the unmanned aerial vehicle is controlled to move, the simulation equipment radiates a radar echo simulation signal, a target trace point is formed in a predetermined radar resolution unit, the radar pushes target information to the command and control system, and the system judges and fuses the target information into the same batch of targets; according to the invention, a single simulation device is used for simulating the same batch of targets for two radars, the working capability of the simulation device is provided, and the influence of a space-time condition fusion gate, a far-field condition and an antenna beam of the simulation device on the deployment position of the simulation device when different track types are simulated is analyzed in an emphasized manner. Theoretical guidance can be provided for two radars to simulate the same batch of target tracks, and the track simulation cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of track simulation, and in particular to a method for simulating the tracks of two radars. Background Art

[0002] The air target environment is a necessary condition for radar to conduct test training, which usually includes real flying targets and simulated targets. Simulated targets have become an important support for building air target environments due to their strong reconfigurability and high cost-effectiveness. They are generally constructed using simulation equipment or semi-physical simulation methods. In particular, the method of using drones equipped with simulation equipment to simulate target tracks has made certain progress in terms of simulated track type, track accuracy, and operational convenience. However, the current track simulation method usually uses one drone equipped with one simulation device to simulate the track of one radar. Therefore, when simulating the same batch of targets for two radars, two drones plus two simulation devices are required to complete the track simulation. On the one hand, it is necessary to operate and control the movement of the two drones. Due to the possible errors in the synchronization between the drone movements, the target track errors formed by the two radars are large, and the command and control system cannot identify them as the same batch of targets. On the other hand, the use of two drones plus two simulation devices also increases the hardware cost and labor cost of track simulation.

[0003] In view of the above reasons, a method for simulating the tracks of two radars is developed. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for simulating the tracks of two radars. A single simulation device is used to simulate the same batch of targets for the two radars, and the working capabilities that the simulation device should have are proposed. The influence of the spatiotemporal fusion gate, far-field conditions and the antenna beam of the simulation device on the deployment position of the simulation device in simulating different track types is analyzed in detail. The simulation results show that the method can provide theoretical guidance for two radars to simulate the tracks of the same batch of targets, thereby reducing the cost of track simulation.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for simulating the tracks of two radars, using a simulation device carried by a drone, forming simulated track sampling points and drone motion control information according to preset simulated track information, position coordinates of two radars, distance resolution, radar scanning cycle and other parameters, solving echo simulation parameters according to the relationship between the simulated track sampling points, radars and simulation devices, controlling the drone movement and the simulation device to radiate radar echo simulation signals, forming target point tracks in predetermined radar resolution units, and the radars push target information to the command and control system respectively, and the system is judged to be integrated into the same batch of targets; the specific steps are:

[0006] S1 simulated target trajectory planning

[0007] According to the needs of the test training, plan the target type, determine the RCS of the simulated target, the initial radial distance from the target to the radar, the direction of movement, the speed of movement, and determine the movement trajectory of the simulated target;

[0008] S2 establishes the mathematical model of the echo simulation signal

[0009] Assume there are two radars, radar A and radar B. The simulation device first receives the radiation signals of the two radars, which are s A (t) and s B (t), signal modulation is performed according to the distance and angle relationship among the simulated track sampling point information, radar, and simulation equipment. The echo simulation signal emitted after modulation by the simulation equipment is expressed as:

[0010]

[0011] In formula (1), k is the amplitude modulation coefficient of the echo simulation signal, A is the antenna scanning pattern of the simulation device, α(t) is the beam azimuth, β(t) is the antenna elevation angle, s(t) is the radar transmission signal received by the simulation device, τ is the time delay corresponding to the simulation track, Phase modulation of the echo analog signal;

[0012] S3 determines the deployment location of the simulated device

[0013] S3.1 samples the simulated target space motion trajectory determined in step S1 to form a simulated target space position point set, and solves the echo power of the simulated target at each position for radar A and radar B according to the radar equation;

[0014] S3.2 Based on the simulated target spatial position point set formed in step S3.1, combined with the deployment position analysis of the simulated equipment under different track types, the deployment position of the simulated equipment is preliminarily determined. Let the simulated equipment be C, the simulated target track point of radar A be M, and the simulated target track point of radar B be N. Radar B is located on the right side of radar A, and the track points are all located on the right side of radar B. The simulated target track point N formed by the simulated equipment C on radar B is used as the fusion track reference. In the process of track fusion, the measurement of the original air situation takes into account the judgment of the distance dimension, and the distance between M and N is required to be as small as possible;

[0015] S3.2.1 Simulated equipment deployment altitude under radial trajectory

[0016] When the simulated track is a radial track relative to both radars, the two radars, the simulated equipment and the simulated track points are all located in the same plane. According to the mapping relationship, the simulated equipment can only be deployed on the line connecting radar B and the simulated target track point N. In terms of spatial relationship, the line segment MN⊥CN. At this time, the distance between N and M is the smallest, and the possibility of successful association between the original air situation and the fused track is the greatest.

[0017] S3.2.1.1 Impact of air situation fusion gate on the deployment height of simulation equipment

[0018] Usually, the height H of the simulated track point, the distance R from the simulated track point to the radar, and the deployment distance d between radar A and radar B are known. The distance d between M and N is mn for:

[0019]

[0020] Where h is the deployment height of the simulation device, and s is the distance from the projection point of the simulation device to the ground to radar A;

[0021] At this point, according to the geometric relationship:

[0022]

[0023] Substituting formula (3) into formula (2) yields:

[0024]

[0025] Assuming that the gate threshold in the fusion air situation processing process is ρ, then d mn ≤ρ, at this time, the simulated equipment deployment height h:

[0026]

[0027] S3.2.1.2 Impact of far-field conditions on the deployment height of simulation equipment

[0028] The deployment location of the simulation equipment must meet the far-field conditions of the radar antenna in space to ensure the phase stability of the echo simulation signal when it is received by the radar. The deployment distance must meet the following requirements:

[0029]

[0030] Where D A and D B are the antenna diameters of radar A and radar B respectively, λ A and λ B are the wavelengths of the transmitted signals of radar A and radar B respectively;

[0031] When the position of the simulation device meets the far-field condition for radar A, the requirement for the height of the simulation device is:

[0032]

[0033] There exists a minimum value h0 that satisfies formula (7), and h0 ≥ 0;

[0034] When the position of the simulation device meets the far-field condition for radar B, the requirement for the height of the simulation device is:

[0035]

[0036] S3.2.1.3 Effect of simulated device antenna beam width on simulated device deployment height

[0037] Assume that the antenna beam widths of the two frequency bands of the simulated equipment of radar A and radar B are θ1 and θ2 respectively, and θ1 ≥ θ2. During the track simulation, the center of the simulated equipment antenna is strictly aligned with radar B, that is, the line BC is the angular bisector of the antenna beam width, and radar A is also required to be located within the corresponding antenna beam width. Since the antenna beam width is fixed, as the deployment height of the simulated equipment increases, the distance of the beam projection on the ground gradually increases; for simulating a target in a certain direction, there is a critical value for the positional relationship between the simulated equipment and radar B. When the simulated equipment is in this critical position, the distance between the simulated equipment and radar B increases. When the deployment height of the simulated device is h', radar A can just receive the radiation signal of the simulated device. At this time, the deployment height of the simulated device is h'. When the deployment height of the simulated device is h<h', radar A is outside the antenna beam width of the simulated device. At this time, the simulated device cannot receive the transmission signal of radar A. When the deployment height of the simulated device is h≥h', radar A is within the antenna beam width of the simulated device. At this time, the simulated device and radar A can receive each other's transmission signals. When the deployment height of the simulated device is h', the angle ∠MCN formed by the simulated device and the two radars is equal to θ1 / 2. At this time:

[0038]

[0039] At this time, the simulated device height is:

[0040]

[0041] When the simulation device and two radars can receive each other's transmission signals, the requirements for the height of the simulation device are:

[0042] h≥h' (11)

[0043] S3.2.1.4 Simulation equipment deployment height selection

[0044] According to formulas (5), (7), (8), and (11), there is a minimum value for the deployment height of the simulated device, and the deployment height is less than the height H of the simulated track point. Therefore, the deployment height of the simulated device is:

[0045]

[0046] S3.2.2 Simulated equipment deployment altitude under tangential track

[0047] When the simulated track is a tangential track relative to one of the radars or a tangential track relative to both radars, the height H of the simulated track point, the distance R from the simulated track to the radar and the deployment position d between the radars are known, the coordinates of the track point and the radar deployment position are known, and the azimuth of the simulated target observed by radar B can be obtained, and at the same time, the angle γ formed by the line CB connecting the simulated device and radar B and the ground can be obtained;

[0048] S3.2.2.1 Impact of air situation fusion gate on the deployment height of simulation equipment

[0049] The distance d between M and N mn for:

[0050]

[0051] Assuming that the gate threshold in the fusion air situation processing process is ρ, then d mn ≤ρ, at this time, the simulated equipment deployment height h:

[0052]

[0053] S3.2.2.2 Impact of far-field conditions on the deployment height of simulated equipment

[0054] According to S3.2.1.2, the deployment location of the simulation equipment must satisfy the far-field conditions of the radar antenna in space, and must also meet the conditions listed in formula (6);

[0055] When the position of the simulation device meets the far-field condition for radar A, the requirement for the height of the simulation device is:

[0056]

[0057] There exists a minimum value h0 that satisfies formula (15), and h0 ≥ 0;

[0058] When the position of the simulated device meets the far-field condition for radar B, the requirement for the height of the simulated device is consistent with equation (8);

[0059] S3.2.2.3 Effect of simulated device antenna beam width on simulated device deployment height

[0060] When simulating the tangential trajectory of the device, the geometric relationship between the antenna beam width at the critical position and the deployment position of the simulated device satisfies formula (9). The height of the simulated device under this condition is:

[0061]

[0062] S3.2.2.4 Simulation equipment deployment height selection

[0063] According to formulas (8), (14), (15), and (16), there is a minimum value for the deployment height of the simulated device, and the deployment height is less than the height H of the simulated track point. Therefore, the deployment height of the simulated device is:

[0064]

[0065] S3.2.3 Analysis of simulated equipment deployment locations

[0066] According to the mapping relationship, whether simulating radial track or tangential track, when the simulated equipment deployment height is h, its distance d to radar B is bc , that is, the deployment distance is:

[0067]

[0068] S3.3 Determine the effective deployment area of ​​the simulation device based on the simulation device deployment position calculated in step S3.2.3, the echo power calculated in step S3.1, the receiver sensitivity and radiation power of the two radars, and the receiving sensitivity and radiation power of the simulation device to ensure that the echo simulation signal can be normally generated and received and processed by the radar. Further, determine the spatial position of the simulation device when simulating each target spatial position point based on the simulated target spatial position point set to form the spatial position point set of the simulation device;

[0069] S4 determines the modulation parameters of the analog device radio signal

[0070] S4.1 Determine the time delay τ of the simulated device radiation signal by the radar ranging principle according to the radar deployment position coordinates, the simulated target spatial position point set determined in step S3.1, and the simulated device spatial position point set determined in step S3.3;

[0071] S4.2 According to the movement speed and spatial posture of the simulated target, the phase modulation of the radiation signal of the simulated device is determined by Doppler

[0072] S4.3 Determine the amplitude modulation coefficient k of the radiation signal of the simulated device according to the set of spatial position points of the simulated device determined in step S3.3, the sensitivity of the radar receiver, and the radiation power of the simulated device by using the electromagnetic wave spatial transmission equation and the radar signal processing algorithm;

[0073] S4.4 Determine a list of signal radiation parameters of the simulation device in the corresponding sampling time interval by combining steps S4.1, S4.2 and S4.3;

[0074] S5 controls the radiated signals of analog devices according to time synchronization requirements

[0075] Use a drone equipped with a simulation device, and control the drone to move to the corresponding position according to the spatial position point set of the simulation device determined in step S3.3. During this period, the simulation device detects and receives the signals of each radar, and completes signal modulation and forwarding according to the modulation parameters of the simulation device radiation signal determined in step S4. Each radar receives the echo simulation signal to form a simulated target and sends the target information to the command and control system. The system performs air situation fusion processing and determines that they are the same batch of targets.

[0076] The beneficial effects of the present invention are as follows: the present invention uses a single simulation device to simulate the same batch of targets for two radars, proposes the working capabilities that the simulation device should have, and focuses on analyzing the influence of the spatiotemporal fusion gate, far-field conditions and the simulation device antenna beam on the deployment position of the simulation device in simulating different track types. The simulation results prove that the method can provide theoretical guidance for two radars to simulate the tracks of the same batch of targets, thereby reducing the track simulation cost. The parts not described in detail in the present invention are existing commonly used technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The present invention will be further described below in conjunction with the accompanying drawings:

[0078] Figure 1 It is a single simulation device simulating the same single track for two radars;

[0079] Figure 2 It is a schematic diagram of the geometric relationship of tangential track simulation;

[0080] Figure 3 It is the change in the geometric relationship between the antenna beam projection and the deployment position of the simulated equipment;

[0081] Figure 4 is the ground projection of the antenna beam at the critical position of the radial track;

[0082] Figure 5 It is a schematic diagram of the geometric relationship of radial track simulation;

[0083] Figure 6 is the ground projection of the antenna beam at the critical position of the tangential track;

[0084] Figure 7 It is the air situation fusion process of the command and control system;

[0085] Figure 8 It is the change of the deployment altitude of the simulated equipment under the radial track;

[0086] Fig. 9 It is the change of the deployment distance of the simulated equipment under the radial track;

[0087] Fig.10 It is the change of the deployment altitude of the simulated equipment under the tangential track;

[0088] Fig.11It is the change of simulated equipment deployment distance under tangential track. DETAILED DESCRIPTION

[0089] The present invention is further described in detail below in conjunction with embodiments and specific implementation modes:

[0090] Example 1

[0091] The two radars usually have different frequency bands and signal systems. The radars are deployed at a certain distance. A single simulation device is used to simulate the tracks of the two radars, and to ensure that these tracks are unified in terms of battle logic, time and space, and electromagnetic characteristics, it is necessary to modulate and process radar transmission signals of different bands, especially to be equipped with different antennas, and to accurately control the radiation timing. In this embodiment, the simulation device has both S and C band hardware working capabilities, and the track simulation of radar A (S band) and radar B (C band) is taken as an example. The simulation diagram is as follows: Figure 1 As shown; after receiving the signals from radars A and B respectively, the simulation equipment modulates the corresponding echo simulation signal according to the simulated track input. The simulated target information formed by radar reception and post-processing is sent to the command and control system, and the system performs air situation fusion processing into the same batch of targets.

[0092] S1. Simulated target trajectory planning

[0093] According to the needs of the test training, plan the target type, determine the RCS of the simulated target, the initial radial distance from the target to the radar, the direction of movement, the speed of movement, and determine the movement trajectory of the simulated target;

[0094] S2 establishes the mathematical model of the echo simulation signal

[0095] Assume there are two radars, radar A and radar B. The simulation device first receives the radiation signals of the two radars, which are s A (t) and s B (t), the signal is modulated according to the distance and angle relationship among the simulated track sampling point information, radar and simulation equipment. The echo simulation signal emitted after modulation by the simulation equipment can be expressed as:

[0096]

[0097] In formula (1), k is the amplitude modulation coefficient of the echo simulation signal, A is the antenna scanning pattern of the simulation device, α(t) is the beam azimuth, β(t) is the antenna elevation angle, s(t) is the radar transmission signal received by the simulation device, τ is the time delay corresponding to the simulation track, Phase modulation of the echo analog signal;

[0098] S3 determines the deployment location of the simulated device

[0099] In order to reduce the design complexity, the simulated device antenna does not add a servo control device, that is, it is assumed that the beam azimuth and elevation angles of the two antennas of the simulated device are the same; according to formula (1) and Figure 1 The analysis shows that the deployment location of the simulation equipment is the key factor affecting the target track simulation;

[0100] S3.1 samples the simulated target space motion trajectory determined in step S1 to form a simulated target space position point set, and solves the echo power of the simulated target at each position for radar A and radar B according to the radar equation;

[0101] S3.2 Based on the simulated target spatial position point set formed in step S3.1, combined with the deployment position analysis of the simulated equipment under different track types, the deployment position of the simulated equipment is preliminarily determined. Let the simulated equipment be C, the simulated target track point of radar A be M, and the simulated target track point of radar B be N. The simulated target track point N formed by the simulated equipment for radar B is used as the fusion track reference. During the track fusion process, the measurement of the original air situation takes into account the judgment of the distance dimension, and the distance between M and N is required to be as small as possible;

[0102] S3.2.1 Simulated equipment deployment altitude under radial trajectory

[0103] When the simulated track is a radial track relative to both radars, the two radars, the simulation equipment and the simulated track points are all located in the same plane. According to the mapping relationship, the simulation equipment can only be deployed on the line connecting radar B and the simulated target track point N. The spatial geometric relationship is as follows: Figure 2 As shown in the figure, in the spatial relationship, the line segment MN⊥CN, at this time the distance between N and M is the smallest, and the possibility of successful association between the original air situation and the fused track is the greatest;

[0104] S3.2.1.1 Impact of air situation fusion gate on the deployment height of simulation equipment

[0105] Usually, the height H of the simulated track point, the distance R from the simulated track point to the radar, and the deployment distance d between radar A and radar B are known. The distance d between M and N is mn for:

[0106]

[0107] Where h is the deployment height of the simulation device, and s is the distance from the projection point of the simulation device to the ground to radar A;

[0108] At this point, according to the geometric relationship:

[0109]

[0110] Substituting formula (3) into formula (2) yields:

[0111]

[0112] Assuming that the gate threshold in the fusion air situation processing process is ρ, then d mn ≤ρ, at this time, the simulated equipment deployment height h:

[0113]

[0114] S3.2.1.2 Impact of far-field conditions on the deployment height of simulation equipment

[0115] The deployment location of the simulation equipment must meet the far-field conditions of the radar antenna in space to ensure the phase stability of the echo simulation signal when it is received by the radar. The deployment distance must meet the following requirements:

[0116]

[0117] Where D A and D B are the antenna diameters of radar A and radar B respectively, λ A and λ B are the wavelengths of the transmitted signals of radar A and radar B respectively;

[0118] When the position of the simulation device meets the far-field condition for radar A, the requirement for the height of the simulation device is:

[0119]

[0120] There exists a minimum value h0 that satisfies formula (7), and h0 ≥ 0;

[0121] When the position of the simulation device meets the far-field condition for radar B, the requirement for the height of the simulation device is:

[0122]

[0123] S3.2.1.3 Effect of simulated device antenna beam width on simulated device deployment height

[0124] Assume that the antenna beam widths of the two frequency bands of the simulated equipment of radar A and radar B are θ1 and θ2 respectively, and θ1 ≥ θ2. During the track simulation, the center of the simulated equipment antenna is strictly aligned with radar B, that is, the line BC is the angular bisector of the antenna beam width, and radar A is also required to be located within the corresponding antenna beam width. Since the antenna beam width is fixed, as the deployment height of the simulated equipment increases, the distance of the beam projection on the ground gradually increases, and the geometric relationship changes as shown in the figure. Figure 3 As shown, from Figure 3 It can be seen that for simulating a target in a certain direction, there is a critical value between the position relationship between the simulation device and radar B. When the simulation device is at this critical position, the geometric relationship between the antenna beam and the deployment position of the simulation device is as follows: Figure 4 As shown, at this time, radar A can just receive the radiation signal of the simulation device. At this time, the deployment height of the simulation device is h'. When the deployment height of the simulation device is h<h', radar A is outside the antenna beam width of the simulation device. At this time, the simulation device cannot receive the transmission signal of radar A. When the deployment height of the simulation device is h≥h', radar A is within the antenna beam width of the simulation device. At this time, the simulation device and radar A can receive each other's transmission signals. When the deployment height of the simulation device is h', the angle ∠MCN formed by the simulation device and the two radars is equal to θ1 / 2. At this time:

[0125]

[0126] At this time, the simulated device height is:

[0127]

[0128] When the simulation device and two radars can receive each other's transmission signals, the requirements for the height of the simulation device are:

[0129] h≥h' (11)

[0130] S3.2.1.4 Simulation equipment deployment height selection

[0131] According to formulas (5), (7), (8), and (11), there is a minimum value for the deployment height of the simulated device, and the deployment height is less than the height H of the simulated track point. Therefore, the deployment height of the simulated device is:

[0132]

[0133] S3.2.2 Simulated equipment deployment altitude under tangential track

[0134] When the simulated track is tangential to one of the radars or tangential to both radars, the spatial geometric relationship is as follows: Figure 5 As shown, the height H of the simulated track point, the distance R from the simulated track to the radar, and the deployment position d between the radars are known. The coordinates of the track point and the radar deployment position are known, and the azimuth of the simulated target observed by radar B can be obtained. At the same time, the angle γ between the line CB connecting the simulated device and radar B and the ground can be obtained.

[0135] S3.2.2.1 Impact of air situation fusion gate on the deployment height of simulation equipment

[0136] At this time, the distance between M and N is d mn for:

[0137]

[0138] Assuming that the gate threshold in the fusion air situation processing process is ρ, then dmn ≤ρ, at this time, the simulated equipment deployment height h:

[0139]

[0140] S3.2.2.2 Impact of far-field conditions on the deployment height of simulated equipment

[0141] According to S3.2.1.2, the deployment location of the simulation equipment must satisfy the far-field conditions of the radar antenna in space, and must also meet the conditions listed in formula (6);

[0142] When the position of the simulation device meets the far-field condition for radar A, the requirement for the height of the simulation device is:

[0143]

[0144] There exists a minimum value h0 that satisfies formula (15), and h0 ≥ 0;

[0145] When the position of the simulated device meets the far-field condition for radar B, the requirement for the height of the simulated device is consistent with equation (8);

[0146] S3.2.2.3 Effect of simulated device antenna beam width on simulated device deployment height

[0147] When simulating the tangential trajectory of the device, the geometric relationship between the antenna beam width at the critical position and the simulated device deployment position is as follows: Figure 6 As shown, according to Figure 6 As shown, the geometric relationship also satisfies formula (9). The height of the simulated device under this condition is:

[0148]

[0149] S3.2.2.4 Simulation equipment deployment height selection

[0150] According to formulas (8), (14), (15), and (16), there is a minimum value for the deployment height of the simulated device, and the deployment height is less than the height H of the simulated track point. Therefore, the deployment height of the simulated device is:

[0151]

[0152] S3.2.3 Analysis of simulated equipment deployment locations

[0153] According to the mapping relationship, whether simulating radial track or tangential track, when the simulated equipment deployment height is h, its distance d to radar B is bc , that is, the deployment distance is:

[0154]

[0155] S3.3 Determine the effective deployment area of ​​the simulation device based on the simulation device deployment position calculated in step S3.2.3, the echo power calculated in step S3.1, the receiver sensitivity and radiation power of the two radars, and the receiving sensitivity and radiation power of the simulation device to ensure that the echo simulation signal can be normally generated and received and processed by the radar. Further, determine the spatial position of the simulation device when simulating each target spatial position point based on the simulated target spatial position point set to form the spatial position point set of the simulation device;

[0156] S4 determines the modulation parameters of the analog device radio signal

[0157] S4.1 Determine the time delay τ of the simulated device radiation signal by the radar ranging principle according to the radar deployment position coordinates, the simulated target spatial position point set determined in step S3.1, and the simulated device spatial position point set determined in step S3.3;

[0158] S4.2 According to the movement speed and spatial posture of the simulated target, the phase modulation of the radiation signal of the simulated device is determined by Doppler

[0159] S4.3 Determine the amplitude modulation coefficient k of the radiation signal of the simulated device according to the set of spatial position points of the simulated device determined in step S3.3, the sensitivity of the radar receiver, and the radiation power of the simulated device by using the electromagnetic wave spatial transmission equation and the radar signal processing algorithm;

[0160] S4.4 Determine a list of signal radiation parameters of the simulation device in the corresponding sampling time interval by combining steps S4.1, S4.2 and S4.3;

[0161] S5 controls the radiated signals of analog devices according to time synchronization requirements

[0162] Use a drone equipped with a simulation device, and control the drone to move to the corresponding position according to the spatial position point set of the simulation device determined in step S3.3. During this period, the simulation device detects and receives the signals of each radar, and completes signal modulation and forwarding according to the modulation parameters of the simulation device radiation signal determined in step S4. Each radar receives the echo simulation signal to form a simulated target and sends the target information to the command and control system. The system performs air situation fusion processing and determines that they are the same batch of targets.

[0163] S6 command and control system air situation fusion

[0164] After each radar detects the air situation information, it sends it to the command and control system. The command and control system receives it and performs time-space registration, that is, converts the position into the position in the coordinate system with the command and control system as the origin, and unifies the time to the current moment. Then, the real-time air situation sent by each radar is associated with the existing fused track. If the association is successful, the filter update is performed. If the association is unsuccessful, it is determined whether a new track can be started. If the track starting conditions are met, a new fused track is established. Otherwise, it is removed as an outlier point. The air situation fusion process is as follows: Figure 7 As shown;

[0165] S7 Simulation Analysis

[0166] Assume that the operating frequency of the two radars A is 900MHz, the antenna diameter is 6m, the distance resolution is less than or equal to 400m, and the antenna beam width of the analog device frequency band is 10°; the operating frequency of radar B is 200MHz, the antenna diameter is 5m, and the distance resolution is less than or equal to 200m;

[0167] When the simulated target flies radially relative to the radar, the deployment height and deployment distance of the simulated equipment change with the simulated target distance and the deployment distance between radars. Figure 8 and Fig. 9 As shown;

[0168] Figure 8 and Fig. 9 The simulation results show that when the deployment distance d between radars remains unchanged, the deployment height of the simulated equipment decreases with the increase of the simulated target distance R, and the deployment distance of the simulated equipment increases with the increase of the simulated target distance; when the simulated target distance remains unchanged, the deployment height h and deployment distance of the simulated equipment increase with the increase of the deployment distance d between radars; when the deployment distance between radars is constant, the deployment distance of the simulated equipment does not change much with the increase of the simulated target distance. When the simulated target distances are 20km and 300km respectively, the simulated target distance increases by 1400%. When the deployment distance between radars is 200m, the deployment distances are 2.05km and 2.281km respectively, and the deployment distance increases by only 11.27%. When the deployment distance between radars is 1000m, the deployment distances are 7.096km and 11.04km respectively, and the deployment distance increases by 55.6%.

[0169] When the simulated target flies tangentially to the radar, assuming that the deployment distance between the radars is 200m, the deployment height and deployment distance of the target simulation equipment change with the simulated target distance and the target azimuth observed by radar B as shown in the following figure: Fig.10 and Fig.11 shown.

[0170] Fig.10 and Fig.11The simulation results show that, when the deployment distance d between radars remains unchanged, the deployment height and deployment distance of the simulated equipment first increase and then decrease with the increase of the azimuth of the simulated target, and reach the maximum when the azimuth is π / 2; when the distance to the simulated target is the same, the deployment height and deployment distance of the simulated equipment under the tangential track are greater than those under the radial track.

Claims

1. A method for simulating the tracks of two radars, characterized in that: Use the simulation equipment carried by the drone to form the simulation track sampling points and the drone motion control information according to the preset simulation track information, the position coordinates of the two radars, the distance resolution, the radar scanning cycle and other parameters. According to the relationship between the simulation track sampling points, the radar and the simulation equipment, the echo simulation parameters are solved, the drone movement and the simulation equipment are controlled to radiate the radar echo simulation signal, and the target point track is formed in the predetermined radar resolution unit. The radar pushes the target information to the command and control system respectively, and the system is judged to be integrated into the same batch of targets; the specific steps are as follows: S1 simulated target trajectory planning According to the needs of the test training, plan the target type, determine the RCS of the simulated target, the initial radial distance from the target to the radar, the direction of movement, the speed of movement, and determine the movement trajectory of the simulated target; S2 establishes the mathematical model of the echo simulation signal Assume there are two radars, radar A and radar B. The simulation device first receives the radiation signals of the two radars, which are s A (t) and s B (t), signal modulation is performed according to the distance and angle relationship among the simulated track sampling point information, radar, and simulation equipment. The echo simulation signal emitted after modulation by the simulation equipment is expressed as: In formula (1), k is the amplitude modulation coefficient of the echo simulation signal, A is the antenna scanning pattern of the simulation device, α(t) is the beam azimuth, β(t) is the antenna elevation angle, s(t) is the radar transmission signal received by the simulation device, τ is the time delay corresponding to the simulation track, Phase modulation of the echo analog signal; S3 determines the deployment location of the simulated device S3.1 samples the simulated target space motion trajectory determined in step S1 to form a simulated target space position point set, and solves the echo power of the simulated target at each position for radar A and radar B according to the radar equation; S3.2 Based on the simulated target spatial position point set formed in step S3.1, combined with the deployment position analysis of the simulated equipment under different track types, the deployment position of the simulated equipment is preliminarily determined. Let the simulated equipment be C, the simulated target track point of radar A be M, and the simulated target track point of radar B be N. Radar B is located on the right side of radar A, and the track points are all located on the right side of radar B. The simulated target track point N formed by the simulated equipment C on radar B is used as the fusion track reference. In the process of track fusion, the measurement of the original air situation takes into account the judgment of the distance dimension, and the distance between M and N is required to be as small as possible; S3.2.1 Simulated equipment deployment altitude under radial trajectory When the simulated track is a radial track relative to both radars, the two radars, the simulated equipment and the simulated track points are all located in the same plane. According to the mapping relationship, the simulated equipment can only be deployed on the line connecting radar B and the simulated target track point N. In terms of spatial relationship, the line segment MN⊥CN. At this time, the distance between N and M is the smallest, and the possibility of successful association between the original air situation and the fused track is the greatest. S3.2.1.1 Impact of air situation fusion gate on the deployment height of simulation equipment Usually, the height H of the simulated track point, the distance R from the simulated track point to the radar, and the deployment distance d between radar A and radar B are known. mn for: Where h is the deployment height of the simulation device, and s is the distance from the projection point of the simulation device to the ground to radar A; At this point, according to the geometric relationship: Substituting formula (3) into formula (2) yields: Assuming that the gate threshold in the fusion air situation processing process is ρ, then d mn ≤ρ, at this time, the simulated equipment deployment height h: S3.2.1.2 Impact of far-field conditions on the deployment height of simulation equipment The deployment location of the simulation equipment must meet the far-field conditions of the radar antenna in space to ensure the phase stability of the echo simulation signal when it is received by the radar. The deployment distance must meet the following requirements: Where D A and D B are the antenna diameters of radar A and radar B respectively, λ A and λ B are the wavelengths of the transmitted signals of radar A and radar B respectively; When the position of the simulation device meets the far-field condition for radar A, the requirement for the height of the simulation device is: There exists a minimum value h0 that satisfies formula (7), and h0 ≥ 0; When the position of the simulation device meets the far-field condition for radar B, the requirement for the height of the simulation device is: S3.2.1.3 Effect of simulated device antenna beam width on simulated device deployment height Assume that the antenna beam widths of the two frequency bands of the simulated equipment of radar A and radar B are θ1 and θ2 respectively, and θ1 ≥ θ2. During the track simulation, the center of the simulated equipment antenna is strictly aligned with radar B, that is, the line BC is the angular bisector of the antenna beam width, and radar A is also required to be located within the corresponding antenna beam width. Since the antenna beam width is fixed, as the deployment height of the simulated equipment increases, the distance of the beam projection on the ground gradually increases; for simulating a target in a certain direction, there is a critical value for the positional relationship between the simulated equipment and radar B. When the simulated equipment is in this critical position, the distance between the simulated equipment and radar B increases. When the deployment height of the simulated device is h', radar A can just receive the radiation signal of the simulated device. At this time, the deployment height of the simulated device is h'. When the deployment height of the simulated device is h<h', radar A is outside the antenna beam width of the simulated device. At this time, the simulated device cannot receive the transmission signal of radar A. When the deployment height of the simulated device is h≥h', radar A is within the antenna beam width of the simulated device. At this time, the simulated device and radar A can receive each other's transmission signals. When the deployment height of the simulated device is h', the angle ∠MCN formed by the simulated device and the two radars is equal to θ1 / 2. At this time: At this time, the simulated device height is: When the simulation device and two radars can receive each other's transmission signals, the requirements for the height of the simulation device are: h≥h' (11) S3.2.1.4 Simulation equipment deployment height selection According to formulas (5), (7), (8), and (11), there is a minimum value for the deployment height of the simulated device, and the deployment height is less than the height H of the simulated track point. Therefore, the deployment height of the simulated device is: S3.2.2 Simulated equipment deployment altitude under tangential track When the simulated track is a tangential track relative to one of the radars or a tangential track relative to both radars, the height H of the simulated track point, the distance R from the simulated track to the radar and the deployment position d between the radars are known, the coordinates of the track point and the radar deployment position are known, and the azimuth of the simulated target observed by radar B can be obtained, and at the same time, the angle γ formed by the line CB connecting the simulated device and radar B and the ground can be obtained; S3.2.2.1 Impact of air situation fusion gate on the deployment height of simulation equipment The distance d between M and N mn for: Assuming that the gate threshold in the fusion air situation processing process is ρ, then d mn ≤ρ, at this time, the simulated equipment deployment height h: S3.2.2.2 Impact of far-field conditions on the deployment height of simulated equipment According to S3.2.1.2, the deployment location of the simulation equipment must satisfy the far-field conditions of the radar antenna in space, and must also meet the conditions listed in formula (6); When the position of the simulation device meets the far-field condition for radar A, the requirement for the height of the simulation device is: There exists a minimum value h0 that satisfies formula (15), and h0 ≥ 0; When the position of the simulated device meets the far-field condition for radar B, the requirement for the height of the simulated device is consistent with equation (8); S3.2.2.3 Effect of simulated device antenna beam width on simulated device deployment height When simulating the tangential trajectory of the device, the geometric relationship between the antenna beam width at the critical position and the deployment position of the simulated device satisfies formula (9). The height of the simulated device under this condition is: S3.2.2.4 Simulation equipment deployment height selection According to formulas (8), (14), (15), and (16), there is a minimum value for the deployment height of the simulated device, and the deployment height is less than the height H of the simulated track point. Therefore, the deployment height of the simulated device is: S3.2.3 Analysis of simulated equipment deployment locations According to the mapping relationship, whether simulating radial track or tangential track, when the simulated equipment deployment height is h, its distance d to radar B is bc , that is, the deployment distance is: S3.3 Determine the effective deployment area of ​​the simulation device based on the simulation device deployment position calculated in step S3.2.3, the echo power calculated in step S3.1, the receiver sensitivity and radiation power of the two radars, and the receiving sensitivity and radiation power of the simulation device to ensure that the echo simulation signal can be normally generated and received and processed by the radar. Further, determine the spatial position of the simulation device when simulating each target spatial position point based on the simulated target spatial position point set to form the spatial position point set of the simulation device; S4 determines the modulation parameters of the analog device radio signal S4.1 Determine the time delay τ of the simulated device radiation signal by the radar ranging principle according to the radar deployment position coordinates, the simulated target spatial position point set determined in step S3.1, and the simulated device spatial position point set determined in step S3.3; S4.2 According to the movement speed and spatial posture of the simulated target, the phase modulation of the radiation signal of the simulated device is determined by Doppler S4.3 Determine the amplitude modulation coefficient k of the radiation signal of the simulated device according to the set of spatial position points of the simulated device determined in step S3.3, the sensitivity of the radar receiver, and the radiation power of the simulated device by using the electromagnetic wave spatial transmission equation and the radar signal processing algorithm; S4.4 Determine a list of signal radiation parameters of the simulation device in the corresponding sampling time interval by combining steps S4.1, S4.2 and S4.3; S5 controls the radiated signals of analog devices according to time synchronization requirements Use a drone equipped with a simulation device, and control the drone to move to the corresponding position according to the spatial position point set of the simulation device determined in step S3.

3. During this period, the simulation device detects and receives the signals of each radar, and completes signal modulation and forwarding according to the modulation parameters of the simulation device radiation signal determined in step S4. Each radar receives the echo simulation signal to form a simulated target and sends the target information to the command and control system. The system performs air situation fusion processing and determines that they are the same batch of targets.

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