Method for simulating high-speed mobile platform guided flight by mounting SAR radar on track system

Abstract

The invention relates to a method for simulating guidance flight of a high-speed mobile platform by mounting an SAR radar on a track system, which comprises the following steps: S0, building a scene model sand table and a guidance flight simulation system which comprises a track system, a servo turntable system and a radar system and is used for simulating the guidance flight process of the high-speed mobile platform; the method comprises the following steps: S1, controlling a servo turntable system to enable a radar system to move along a track system according to a set moving distance and moving speed, and collecting distance-azimuth two-dimensional echo data of a scattering point target on a scene model sand table; s2, performing imaging processing on the distance-azimuth two-dimensional echo data to obtain an echo imaging picture; and S3, carrying out image matching and distance registration on the echo imaging image and a preset prior optical image. According to the invention, the high-simulation-degree simulation flight of the high-speed mobile platform guided by the synthetic aperture radar can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of high-speed mobile platform guidance simulation, and in particular to a method for simulating high-speed mobile platform guidance flight by mounting a SAR radar on a track system. Background Art

[0002] When verifying the guidance performance of synthetic aperture radar mounted on a newly developed high-speed mobile platform or verifying the working mode of synthetic aperture radar under different guidance modes, it is necessary to pre-verify the feasibility of the equipment from a theoretical level before conducting field live ammunition guided strikes on set targets. At present, helicopters are often used to perform level maneuvers and dive maneuvers and mount synthetic aperture radars to simulate the workflow of synthetic aperture radar guidance in different flight stages of high-speed mobile platforms, that is, the flight trajectory of helicopters is used to equivalently simulate the flight trajectory of high-speed mobile platforms and verify the guidance performance of synthetic aperture radars in different working modes. However, there are some unavoidable problems in using helicopters instead of high-speed mobile platforms to simulate the flight trajectory of high-speed mobile platforms. First, due to the difference in flight speed between high-speed mobile platforms and helicopters, the flight speed of helicopters is between 240 kilometers and 310 kilometers per hour, while the flight speed of missiles is generally around Mach 4 to 5 (1 Mach is equivalent to 1225 kilometers per hour). Therefore, the difference in the movement speed of the payload platform will cause distortion in the azimuth sampling of the synthetic aperture radar during the echo data processing process, which makes the feasibility verification of the high-speed mobile platform problematic. Secondly, due to the difference in the fluid mechanics and aerodynamic shape of the helicopter and the high-speed mobile platform, the movement posture is also different. Therefore, the helicopter may not be as flexible as the high-speed mobile platform in the transformation of the roll angle and the tilt angle, which will also affect the radar fitting accuracy of the synthetic aperture radar during the live-fire guidance process. Finally, due to the difference in the flight altitude between the high-speed mobile platform and the helicopter, the radar has the problem of distortion of the simulated geometric relationship ratio for the working modes such as the positive side view and the oblique front view during the imaging processing, and affects the subsequent echo data imaging processing algorithm. In addition, since the synthetic aperture radar hardware mounted on the helicopter is in the test and verification stage, the robustness of its radar performance is relatively low, and the helicopter needs to be used to repeatedly conduct level maneuvers and dive maneuvers. This still results in certain consumption in the verification cost, such as the consumption of helicopter flight resources, the coordination of debugging personnel and the occupation of airspace. In addition, the test of synthetic aperture radar hardware equipment mounted on the helicopter is not conducive to scientific researchers to adjust and modify the synthetic aperture radar hardware parameters in real time. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for simulating the guided flight of a high-speed mobile platform by mounting a SAR radar on a track system, which can eliminate the problems of geometric configuration distortion, azimuth echo data processing and scanning beam flexibility existing in the traditional application of a helicopter-mounted synthetic aperture radar to simulate and verify the synthetic aperture radar mounted on a high-speed mobile platform, avoid the negative impact when verifying the guidance performance of the synthetic aperture radar mounted on a newly developed high-speed mobile platform or when verifying the working mode of the synthetic aperture radar under different guidance modes, and realize the simulation flight of a high-simulation mobile platform guided by the application of synthetic aperture radar with high simulation degree.

[0004] The technical solution adopted by the present invention to solve the technical problem is: to provide a method for simulating high-speed mobile platform guided flight by mounting SAR radar on a track system, comprising:

[0005] S0 builds a scene model sandbox and a guided flight simulation system, wherein the guided flight simulation system includes a track system, a servo turntable system and a radar system, and is used to simulate the guided flight process of a high-speed mobile platform;

[0006] S1 controls the servo turntable system to make the radar system move along the track system according to the set moving distance and moving speed, and at the same time collects the distance-azimuth two-dimensional echo data of the scattering point targets on the scene model sand table;

[0007] S2 performs imaging processing on the distance-azimuth two-dimensional echo data to obtain an echo imaging image;

[0008] S3 performs image matching and distance registration on the echo imaging image and the preset prior optical image.

[0009] Furthermore, the collecting of distance-azimuth two-dimensional echo data of scattering point targets on the scene model sandbox includes:

[0010] The number of azimuth dimension moments is calculated according to the moving distance and moving speed of the radar system and the radar pulse repetition interval of the radar system;

[0011] According to the operating altitude and moving speed of the radar system at the current azimuth moment, the slant range from the scattering point target on the scene model sandbox to the radar system is calculated;

[0012] Traversing the azimuth dimension time, calculating the slant range history of all the scattering point targets to the radar system as phase history two-dimensional data;

[0013] After pulse compression processing is performed on the phase history two-dimensional data in the distance dimension and data accumulation processing is performed in the azimuth dimension, the range-azimuth two-dimensional echo data of the scattering point target are extracted from the obtained two-dimensional impulse function matrix.

[0014] Furthermore, the pulse compression processing of the phase history two-dimensional data in the distance dimension is achieved by de-linear frequency modulation.

[0015] Furthermore, the track system includes a first track and a second track, which are used to simulate the horizontal autonomous cruise maneuvering section and the downward dive flight maneuvering section in the missile flight trajectory respectively.

[0016] Furthermore, before step S1, a step of setting parameters of the servo turntable system is also included, specifically including:

[0017] Set whether to perform scanning action;

[0018] Set the scanning angle of the radar system when it is running on the first track and the second track respectively.

[0019] Furthermore, before step S1, the method further includes a step of setting parameters of the radar system, including setting the pulse width and signal bandwidth of the radar signal.

[0020] Furthermore, before step S1, a step of aligning the timestamp of the radar transmission signal with the time when the radar system starts to move is included.

[0021] Furthermore, before step S2, the method further includes the steps of sequentially performing high-pass filtering on the range-azimuth two-dimensional echo data and recovering target characteristic phase information.

[0022] Furthermore, the scene model sandbox is within the beam range of the first radar system.

[0023] Furthermore, the guided flight simulation system is constructed by the following method:

[0024] Obtaining the flight trajectory of the high-speed mobile platform to be simulated during the guided flight process;

[0025] A track system is constructed to simulate the flight trajectory, and a radar system and a servo turntable system are mounted on the track system to respectively simulate the radar system and the antenna servo mechanical system mounted on the high-speed mobile platform.

[0026] Beneficial Effects

[0027] Due to the adoption of the above-mentioned technical scheme, the present invention has the following advantages and positive effects compared with the prior art: the present invention simplifies the actual field verification test into actual echo signal data processing and guidance theory verification through the principle of geometric scaling, and solves the problem of limited simulation fitting degree when the helicopter is equipped with a synthetic aperture radar to simulate the actual high-speed mobile platform guided flight in principle, reduces the helicopter's repeated leveling and dive maneuvering tests, reduces the flight resource consumption, and reduces the experimental verification costs of debugging personnel and airspace occupation, and the simulation of the guided flight process of the high-speed mobile platform is clear and concise, which effectively enhances the learning efficiency of beginners. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of an experimental scenario of an implementation mode of the present invention;

[0029] Figure 2 is a schematic diagram of a mobile platform according to an embodiment of the present invention;

[0030] Figure 3 is a schematic diagram of a mounting servo turntable system according to an embodiment of the present invention;

[0031] Figure 4 1 is a schematic diagram of the operation of a positive side-view imaging radar according to an embodiment of the present invention;

[0032] Figure 5 It is a schematic diagram of the experimental process of an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0034] The embodiment of the present invention relates to a method for using a proportionally scaled verification indoor track model to simulate a high-speed mobile platform mounted with a synthetic aperture radar to achieve guided flight, which can achieve a high degree of simulation of a high-speed mobile platform using a synthetic aperture radar for guided flight, that is, under the conditions of a proportionally scaled indoor environment, from the three dimensions of geometric configuration theory verification, actual echo generation and measured data processing imaging, a high-fidelity and high-fitting simulation of an actual interactive battlefield high-speed mobile platform mounted with a synthetic aperture radar to guide flight and strike targets. The specific technical solution is:

[0035] Determine the approximate route planning during the high-speed mobile platform guided flight that needs to be simulated, including the launch climb phase, the horizontal autonomous cruise maneuver phase, and the downward dive flight maneuver phase.

[0036] Components are replaced according to relevant modules that need to be verified for guided flight of high-speed mobile platform, the missile flight trajectory is simulated by using indoor fixed track system, the antenna servo mechanical system of the mounted synthetic aperture radar is simulated by using three-axis servo turntable, and the mounted synthetic aperture radar is replaced by miniSAR radar with lower radiation power.

[0037] Design the indoor fixed track system's level flight stage height and distance, downward stage height and distance, servo turntable's positive and side view (scanning) downward viewing angle variation range, forward oblique view oblique viewing angle variation range, and descent stage scanning servo turntable rotation range and rotation speed;

[0038] A track system, servo turntable system and synthetic aperture radar system are built indoors. In order to achieve a high-simulation effect, a sand table simulating mountain, city and desert scene models is built indoors. At the same time, it is calculated whether the designed geometric configuration is proportional to the geometric configuration of the high-speed mobile platform mounted with synthetic aperture radar for open-mechanism guided flight in actual combat.

[0039] Plan the horizontal flight path (horizontal segment) of the simulated high-speed mobile platform, assuming its length is L hor , calculate the moving distance r of the simulated high-speed mobile platform on the track system at each moment hor , moving speed v hor , operating height h hor :

[0040] Plan the downward flight path (downward flight path) of the simulated high-speed mobile platform, and set its length as L dec Calculate the moving distance r of the simulated high-speed mobile platform on the track system at each moment dec , moving speed v dec , operating height h dec :

[0041] Plan the parameters of the synthetic aperture radar mounted on the simulated high-speed mobile platform, including the signal bandwidth B r , pulse width T p , signal modulation frequency γ, signal carrier frequency f c , pulse repetition frequency PRF, distance dimension sampling frequency f r and radar antenna azimuth θ azi / pitch angle θ ran The signal waveform of the radar is a linear frequency modulation signal, and the carrier frequency of the signal is e j2πfct , t is the full time including the slow time t a (azimuth time) and fast time t r (distance to time) two types, with t = t a +t r ;

[0042] Plan the parameters of the servo turntable mounted on the simulated high-speed mobile platform, including the lower viewing angle θ in the front and side view (scanning) mode down 、The lower viewing angle θ in the front squint mode down With the oblique angle θ slant Angle size, angular velocity ω in scanning mode r With the rotation angle range θ cir Parameter information is sent:

[0043] After setting the parameters of the track system, servo system and synthetic aperture radar system, the simulated high-speed mobile platform mounted with synthetic aperture radar at a certain azimuth time t can be obtained. azi (i) The obtained measured range-azimuth 2D original echo data matrix M r×a At the same time, a three-dimensional space coordinate axis O-XYZ is established according to the middle position of the horizontal section of the indoor track system;

[0044] Taking the level flight as an example, for any azimuth slowing time t azi (i) Based on the height H of the synthetic aperture radar mounted on the simulated high-speed mobile platform radar (t azi ) (ignore the mounting distance between the synthetic aperture radar and the payload platform) and a certain scattering point target P(x tar ,y tar ,z tar ), the three-dimensional space distance method is used to solve the slant range history R of the synthetic aperture radar from the scattering point target P i , its formula:

[0045]

[0046] From the moment when the synthetic aperture radar starts working to the moment when the synthetic aperture radar ends collecting data, the azimuth accumulation time t azi (i) By calculating the slant range history R from the ground scattering point to the synthetic aperture radar i It can be obtained that the slope distance history R i The phase history φ required for imaging processing i There is a relationship. By performing pulse compression processing on the two-dimensional data of the phase history in the distance dimension and data accumulation processing in the azimuth dimension, a two-dimensional impact function matrix of the set scattering points can be obtained.

[0047] In order to better fit the actual working mode of synthetic aperture radar, it is necessary to analyze the working mode of the mounted synthetic aperture radar. Here we use strip-type positive side imaging for analysis. Since the orbit height of the indoor orbit model system is determined by h hor And combined with the viewing angle θdown and the pitch angle θ ran , therefore, the projection area R of its radar beam on the ground zoom It is determined, and its formula can be expressed as:

[0048] R zoom =h hor tan(θ down +θ ran / 2)-h hor tan(θ down -θ ran / 2);

[0049] If the recorded radar echo is to be imaged, the sand table model needs to be placed within the radar beam range, and in order to improve the simulation fit, a corner reflector model can be appropriately placed within the beam range.

[0050] When synthetic aperture radar transmits a signal, it first generates a baseband signal And perform digital up-conversion on the baseband signal, that is, add the carrier frequency f c The main purpose is to reduce the size of the transmitting antenna, which is conducive to lightweight integration of equipment. After the LFM signal is formed, it is transmitted by the antenna. The mathematical expression of the transmitted signal can be written as:

[0051]

[0052] A r (t a ) is a commonly used rectangular gate distance dimension window function representation, which can be expressed as:

[0053]

[0054] Then, after the receiving antenna receives the echo signal, it performs down-conversion processing (also often called carrier removal) on the echo signal. The expression of the echo signal can be written as:

[0055]

[0056] Same formula A r (t a ), A a (t a ) is the azimuth window function, and δ i The scattering coefficient of a scattering point in the scene is related to the antenna pattern of the receiving antenna.

[0057] In the above formula, 2R(t a ; R Di ) / c represents the time delay τ from the time the transmitted signal is transmitted to the time it is reflected by the target and then received by the receiving antenna;

[0058] and They respectively represent the baseband signal phase delay and the azimuth phase after carrier removal reception.

[0059] In an ideal situation, the attenuation of the echo signal due to the multipath effect in the spatial transmission process is ignored, and the azimuth window function is set to a rectangular window like the range-dimensional rectangular window function;

[0060] By calculation, the echo time domain signal model expression of the LFM signal in the range-azimuth two-dimensional section can be solved as follows:

[0061]

[0062] In the above expression It is expressed as the phase envelope of the scattering point signal;

[0063] After obtaining the above echo signals, the original two-dimensional echo data containing the simulated sandbox scene can be obtained. Then, the echo signals need to be imaged and processed in the following ways: distance-dimensional pulse compression; there are two practical forms of pulse compression: matched filtering and de-linear frequency modulation. In order to be more in line with the pulse compression method of synthetic aperture radar in actual engineering, we use de-linear frequency modulation (Dechirp) which is widely used in engineering.

[0064] De-linear frequency modulation is a pulse compression method suitable for small scenes. Its main advantage is that when processing large-bandwidth signals, the calculation processing is relatively simple, which can simplify the calculation operation and reduce the hardware cost of the equipment.

[0065] The linear frequency modulation method is the same as the matched filtering method. Both methods require the selection of a suitable reference signal, but the form of the reference signal is different. The linear frequency modulation method requires the selection of a reference slant distance R ref To construct the signal, the signal can be expressed as:

[0066]

[0067] The above formula is the reference signal composition in the constructed Dechirp operation. In fact, it is essentially similar to the matched filter operation. The main difference is the setting of the reference slant range. By combining the linear frequency modulation echo signal with the reference slant range signal s ref (t,f n ) after Dechirp processing to obtain the difference frequency echo signal s if (t,f n ) can be expressed as:

[0068]

[0069] The echo signal after the range-dimensional difference frequency reception can be obtained as:

[0070]

[0071] γ=Δf / t0 is the frequency modulation rate contained in the linear frequency modulation signal, which represents the speed of the frequency step change of the linear frequency modulation signal. if By performing an inverse Fourier transform at time t (t), we can obtain the one-dimensional range image of the focused scattering point:

[0072]

[0073] At this point, a one-dimensional impact signal in the distance dimension has been formed, and the azimuth dimension echo data will be subsequently accumulated and processed. The different processing of the azimuth dimension echo data can divide the imaging algorithm into two types: time domain and frequency domain, such as: back-projection imaging algorithm, frequency-scaling imaging algorithm, range Doppler imaging algorithm, range migration imaging algorithm, etc. However, this patent mainly emphasizes a method of using proportional scaling to verify the indoor track model to simulate the actual battlefield high-speed mobile platform mounted with a synthetic aperture radar to achieve guided flight. Therefore, the time / frequency domain imaging processing algorithm will not be described in detail.

[0074] Finally, the parameters of the simulated high-speed mobile platform required for the planning of the servo turntable system, synthetic aperture radar, and track system to complete an imaging guidance are issued, and the synthetic aperture radar transmits the recorded simulated sand table model echo data file to the internal processing unit, that is, the feasibility of the synthetic aperture radar mounted on the high-speed mobile platform can be verified through indoor simulation.

[0075] The following is further explained with reference to the accompanying drawings and experimental applications.

[0076] like Figure 1 As shown in the figure, the simulated high-speed mobile platform mounted with synthetic aperture radar is fixed at a certain position of the indoor track system. Figure 2 As shown, the mounting servo turntable system is as follows Figure 3 As shown. According to the designed indoor track system control module, servo turntable system control module, and synthetic aperture radar control module, the display and control interface is designed. The display and control interface is also used to plan the moving speed, moving distance, scanning mode, and related parameters required by the synthetic aperture radar of the simulated high-speed mobile platform in the horizontal / descending section.

[0077] Example 1

[0078] Example 1: The schematic diagram of the method of the present invention for simulating the horizontal guided flight of a high-speed mobile platform is shown in the following figure. Figure 4 shown.

[0079] To better illustrate Figure 4The distance dimension of the synthetic aperture radar location is set to 0m, the azimuth dimension is set to 0m, and the height is set to 3.2m. At the same time, a trajectory of a high-speed mobile platform horizontal maneuvering flight is simulated, with the starting azimuth dimension position of 0m and the end azimuth dimension position of 2.2m. The synthetic aperture radar is mounted on the simulated high-speed mobile platform, and the simulated high-speed mobile platform moves on the indoor track system according to the parameters issued by the indoor track system display and control module.

[0080] Figure 5 The method of the present invention is applied to simulate the high-speed mobile platform radar open-mechanism guidance flight experiment process (horizontal section), including the following steps:

[0081] A1) The simulated high-speed mobile platform is reset to zero and reset to the starting point of the indoor track system, waiting for the platform movement and echo data collection instructions to be issued.

[0082] A2) Setting parameters for the simulated high-speed mobile platform on the display and control interface of the indoor rail system, specifically: setting the running distance of the simulated high-speed mobile platform for scanning the first section, setting the running distance of the simulated high-speed mobile platform for scanning the second section, setting the running speed of the simulated high-speed mobile platform for scanning the first section, and setting the running speed of the simulated high-speed mobile platform for scanning the second section.

[0083] A3) Set the parameters of the servo turntable mounted on the simulated high-speed mobile platform on the servo turntable system display and control interface, specifically: set whether to perform a scanning action, set the scanning angle of the first scanning segment of the simulated high-speed mobile platform, and set the scanning angle of the second scanning segment of the simulated high-speed mobile platform.

[0084] A4) Setting the parameters of the radar radio frequency of the servo turntable on the radar radio frequency system display and control interface, specifically: setting the pulse width of the transmitted radar signal and setting the signal bandwidth of the transmitted radar signal.

[0085] A5) After setting the parameters of the servo turntable system display and control interface, the radar RF system display and control interface, and the indoor track system display and control interface, the timestamps of the simulated high-speed mobile platform and the radar RF module are reset to zero and aligned. Specifically: set the time of the transmitted radar signal to zero, and set the time point when the simulated high-speed mobile platform starts to move to zero.

[0086] A6) Simulate the high-speed mobile platform to start moving and the radar RF module to start collecting data. Specifically, the high-speed mobile platform starts moving according to the parameters issued by the display and control system (moving distance and moving speed), and the radar RF module maps the sand table model to the slant range plane for distance sampling at each azimuth moment.

[0087] A61) The calculation method of the azimuth dimension sampling number is to divide the moving distance issued by the indoor track system by the moving speed issued, and obtain the time consumed by this experiment. The time consumed by this experiment is divided by the radar pulse repetition interval (pulse repetition interval = unit time / pulse repetition frequency) to obtain the azimuth dimension sampling point number;

[0088] A62) The radar radio frequency acquires the range-azimuth two-dimensional echo data in real time, and the data volume increases with the movement of the simulated high-speed mobile platform, and the final echo data volume is the number of sampling points in the azimuth dimension multiplied by the number of sampling points in the range dimension (number of sampling points in the range dimension = unit time / range dimension sampling frequency);

[0089] A7) Simulate the high-speed mobile platform to stop moving and the radar RF module to stop collecting data. Specifically, simulate the high-speed mobile platform to stop moving (moving distance) according to the parameters issued by the display and control system, and the radar RF module stops mapping the sand table model on the slant range plane for distance sampling at the last azimuth moment.

[0090] A71) At this time, in order to facilitate the Fourier transform of the distance-azimuth two-dimensional echo data in the subsequent imaging processing, the position where the azimuth dimension is zero is overlapped with the moment when the distance dimension data is collected is zero, and the time is delayed at the end position, so that the data termination point can be located more conveniently during the echo data imaging processing, thereby simplifying the amount of data that needs to be calculated.

[0091] A8) After the parameters of the servo turntable system display and control interface, radar RF system display and control interface and indoor track system display and control interface are set, the timestamps of the simulated high-speed mobile platform and the radar RF module are reset and aligned. Specifically: set the time reset of the transmitted radar signal, and set the simulated high-speed mobile platform to be ready to receive the next stage of instructions issued by the indoor track system display and control part.

[0092] A9) The radar beam illuminates the sand table scene and stores the diffusely reflected echoes. The data at this time is sorted and distributed according to the azimuth dimension and time. The data at this time is converted into discrete echo data through A / D sampling inside the radar RF system. At the same time, since the radar RF transmits a signal carried by the carrier frequency, it is necessary to perform digital down-conversion (remove the carrier frequency) at the hardware terminal to convert it into a baseband signal, and then perform echo imaging processing.

[0093] A91) The original range-azimuth two-dimensional echo data contains the characteristic phase information of the target and scene clutter noise. Generally, in the hardware processing process, it needs to be filtered through a high-pass filter, and then the target characteristic phase information is restored. In addition, the subsequent operation of echo signal processing, range-dimensional pulse compression, needs to be selected according to the characteristics of the signal itself.

[0094] A10) The distance-azimuth two-dimensional echo data matrix imaging processing ultimately needs to form two impulse functions in both the distance dimension and the azimuth dimension. A two-dimensional impulse sinc function can be obtained by orthogonally superimposing the two impulse functions.

[0095] A101) Before forming the two-dimensional impact sinc function, the distance dimension pulse compression methods mentioned above: the time-frequency domain matched filter algorithm and the frequency domain dechirp algorithm can convert the range-azimuth two-dimensional time domain echo signal to time domain focusing or frequency domain focusing in the distance dimension. However, due to the motion characteristics of the synthetic aperture radar, the distance change characteristics between the radar and the target have a Doppler effect. Therefore, after the distance compression, the image of the point target will form a curved curve (azimuth dimension) in the image domain. This curve is actually an inverse curve function of the slant range history. The prototype of its change is shown in the following expression:

[0096]

[0097] A102) This bending phenomenon is called range migration. Range migration is formed by the first-order range movement and the second-order range bending in the phase history data, as shown in the following expression:

[0098]

[0099] A103) Different imaging algorithms have different correction methods, but the ultimate goal of the correction processing algorithm is to correct the curved straight line into a straight line and then perform azimuth compression. In the present invention, the basic operation of the range Doppler algorithm in azimuth dimension processing will be briefly described, that is, the range Doppler algorithm deduces the azimuth frequency modulation function related to the radar speed based on the change relationship of the slant range history between the target and the radar. This function is the range migration correction function, and because the range Doppler algorithm is a frequency domain algorithm, it only needs to perform azimuth compression (azimuth dimension Fourier transform) after completing the range migration correction. If there is a large squint angle, there will be a secondary range migration correction. In this embodiment, the simulation is that the squint angle of the positive side view imaging is zero, so there is no large squint angle.

[0100] A11) The matching of echo imaging image and prior optical image is mainly to simulate the high-speed mobile platform in the horizontal section after recording the echo data and performing imaging processing, and then, according to the actual working mode of the high-speed mobile platform, image matching and distance registration will be performed with the optical prior information pre-stored inside. By matching the imaging information map with the optical prior information image, the correctness of the guided flight route is confirmed, and it is determined whether a guided adjustment maneuver is required. Here, this patent mainly emphasizes the simulation of the process method of using an indoor track system to simulate the high-speed mobile platform mounted with a synthetic aperture radar for guided flight. Therefore, image matching and distance registration will not be elaborated.

[0101] A12) Since the patent of the present invention uses a proportional scaling method to simplify the process principle of the radar-guided flight of a high-speed mobile platform in actual combat into a simulation method of an indoor track system simulating a high-speed mobile platform, it is also necessary to image and process the data recorded by the radar radio frequency and feed it back to the display control platform to perform related operations such as imaging result observation, imaging quality analysis and image matching result display.

Claims

1. A method for simulating high-speed mobile platform guided flight by mounting SAR radar on a track system, characterized in that: include: S0 builds a scene model sandbox and a guided flight simulation system, wherein the guided flight simulation system includes a track system, a servo turntable system and a radar system, and is used to simulate the guided flight process of a high-speed mobile platform; S1 controls the servo turntable system to make the radar system move along the track system according to the set moving distance and moving speed, and at the same time collects the distance-azimuth two-dimensional echo data of the scattering point targets on the scene model sand table; S2 performs imaging processing on the distance-azimuth two-dimensional echo data to obtain an echo imaging image; S3 performs image matching and distance registration on the echo imaging image and the preset prior optical image.

2. The method according to claim 1, characterized in that The collecting of distance-azimuth two-dimensional echo data of scattering point targets on the scene model sandbox includes: The number of azimuth dimension moments is calculated according to the moving distance and moving speed of the radar system and the radar pulse repetition interval of the radar system; According to the operating altitude and moving speed of the radar system at the current azimuth moment, the slant range from the scattering point target on the scene model sandbox to the radar system is calculated; Traversing the azimuth dimension time, calculating the slant range history of all the scattering point targets to the radar system as phase history two-dimensional data; After pulse compression processing is performed on the phase history two-dimensional data in the distance dimension and data accumulation processing is performed in the azimuth dimension, the range-azimuth two-dimensional echo data of the scattering point target are extracted from the obtained two-dimensional impulse function matrix.

3. The method according to claim 2, characterized in that The pulse compression processing of the phase history two-dimensional data in the distance dimension is achieved by de-linear frequency modulation.

4. The method according to claim 1, characterized in that: The track system comprises a first track and a second track which are used to simulate the horizontal autonomous cruise maneuvering section and the downward pressure dive flight maneuvering section in the missile flight trajectory respectively.

5. The method according to claim 4, characterized in that Before step S1, the method further includes the step of setting parameters of the servo turntable system, specifically including: Set whether to perform scanning action; Set the scanning angle of the radar system when it is running on the first track and the second track respectively.

6. The method according to claim 1, characterized in that Before step S1, the method further includes the step of setting parameters of the radar system, including setting the pulse width and signal bandwidth of the radar signal.

7. The method according to claim 1, characterized in that Before step S1 , the method further includes a step of aligning the time stamp of the radar transmission signal with the time when the radar system starts to move.

8. The method according to claim 1, characterized in that: Before step S2, the method further includes the steps of sequentially performing high-pass filtering on the range-azimuth two-dimensional echo data and recovering target characteristic phase information.

9. The method according to claim 1, characterized in that: The scene model sandbox is within the beam range of the first radar system.

10. The method according to claim 1, characterized in that The guided flight simulation system is constructed by the following method: obtaining the flight trajectory of the high-speed mobile platform to be simulated during the guided flight; A track system is constructed to simulate the flight trajectory, and a radar system and a servo turntable system are mounted on the track system to respectively simulate the radar system and the antenna servo mechanical system mounted on the high-speed mobile platform.

Images