An active complex jamming method and system for synthetic aperture radar

Abstract

The application provides a synthetic aperture radar active composite jamming method and system, the method comprising: acquiring intermediate frequency radar signals to be jammed, radar related parameters and control parameters; calling DSP and multiple FPGA calculation boards to calculate modulation coefficients corresponding to each false scattering point according to pre-downloaded deception templates and radar related parameters; generating deception jamming signals corresponding to the intermediate frequency radar signals according to the intermediate frequency radar signals and the modulation coefficients corresponding to each false scattering point; generating suppression jamming signals corresponding to the intermediate frequency radar signals according to the control parameters; and determining composite jamming signals corresponding to the intermediate frequency radar signals according to the deception jamming signals and the suppression jamming signals corresponding to the intermediate frequency radar signals. The application can obtain composite jamming signals, has better jamming effect, is not easy to expose the position of the jammer, and has lower cost of the jammer. The signal processing architecture of DSP and FPGA is adopted, the calculation performance of the system is improved, and the real-time performance of system simulation is ensured.

Description

Technical Field

[0001] This application relates to the field of radar technology, and in particular to an active composite jamming method and system for synthetic aperture radar. Background Technology

[0002] Synthetic Aperture Radar (SAR) is an advanced high-resolution microwave imaging radar with many advantages, including high processing gain and strong anti-jamming capabilities, playing a vital role in modern information warfare. With the rapid development of SAR technology, research into SAR jamming techniques also has significant military value in order to seize the "information high ground" and protect important information from reconnaissance.

[0003] In terms of the source of jamming energy, jamming against SAR systems can be divided into two main categories: active jamming and passive jamming. Active jamming, due to its greater flexibility and effectiveness compared to passive jamming, is widely used in electronic warfare. Active jamming is further divided into suppression jamming and deception jamming.

[0004] Current SAR jamming methods typically employ a single jamming mode to interfere with SAR signals emitted by enemy radar. However, a single suppression jamming method requires high processing gain of the jammer against the enemy radar's SAR signal, necessitating high transmission power to achieve a good jamming effect and making the jammer's location easily detectable. A single deception jamming method requires the jammer to introduce false scenes or numerous false targets into the SAR signal based on a deception template. However, deception templates often consist of a large number of false scattering points, and the calculation of the jamming modulation function is time-consuming, thus posing a challenge to the real-time performance of large-scale SAR deception jamming. Furthermore, with the continuous development of electronic countermeasures technology, a single jamming mode may not be able to achieve effective jamming. Even if it can, it requires a high cost, such as increased equipment costs due to increased jammer transmission power and reduced jammer concealment, resulting in a low cost-effectiveness ratio. Summary of the Invention

[0005] In view of this, this application provides an active composite jamming method and system for synthetic aperture radar to solve the above-mentioned technical problems, and the technical solution is as follows:

[0006] An active composite jamming method for synthetic aperture radar, applied to a baseband subsystem, includes:

[0007] Acquire the intermediate frequency radar signal to be jammed, radar-related parameters, and control parameters. Among them, the radar-related parameters refer to the related parameters of the synthetic aperture radar that transmits the intermediate frequency radar signal.

[0008] The digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) are invoked to calculate the modulation coefficients corresponding to each false scattering point based on the pre-downloaded deception template and radar-related parameters.

[0009] Based on the modulation coefficients corresponding to the intermediate frequency radar signal and each false scattering point, a deception jamming signal corresponding to the intermediate frequency radar signal is generated.

[0010] Based on the control parameters, generate the suppression jamming signal corresponding to the intermediate frequency radar signal;

[0011] Based on the deception jamming signal and the suppression jamming signal corresponding to the intermediate frequency radar signal, the composite jamming signal corresponding to the intermediate frequency radar signal is determined.

[0012] Optionally, the radar-related parameters include the aircraft's position and speed information from the synthetic aperture radar;

[0013] The system utilizes a digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) to calculate the modulation coefficients corresponding to each false scattering point based on pre-downloaded deception templates and radar-related parameters. These coefficients include:

[0014] The DSP is invoked to calculate the beam illumination range of the synthetic aperture radar based on the radar-related parameters, and based on the radar beam illumination range, the task of calculating the modulation coefficients corresponding to multiple false scattering points in the deception template is assigned to multiple FPGA computing boards.

[0015] The multiple FPGA computing boards are invoked to determine the distances between the false scattering points under the computing tasks corresponding to the multiple FPGA computing boards and the antenna phase center of the synthetic aperture radar, based on the carrier position and speed information. These distances are used as the scattering point distances corresponding to the false scattering points under the computing tasks corresponding to the multiple FPGA computing boards.

[0016] The multiple FPGA computing boards are invoked to extract the scattering cross-section data of the false scattering points under the corresponding computing task based on the beam illumination range;

[0017] The multiple FPGA computing boards are invoked to determine the amplitude-weighted scattering coefficients corresponding to the false scattering points under the corresponding computing task based on the beam illumination range, the pre-stored azimuth weighting factor table and range weighting factor table, and the scattering cross section data of the false scattering points under the corresponding computing task.

[0018] Multiple FPGA computing boards are invoked to calculate the modulation coefficients corresponding to the spurious scattering points under the corresponding computing tasks, based on the scattering point distance and amplitude weighted scattering coefficients, so as to obtain the modulation coefficients corresponding to each spurious scattering point.

[0019] Optionally, based on the scattering point distance and amplitude-weighted scattering coefficient corresponding to the spurious scattering points under the corresponding computation task, the modulation coefficients corresponding to the spurious scattering points under the corresponding computation task are calculated, including:

[0020] Based on the distances of the scattering points corresponding to the spurious scattering points under the corresponding computational task, determine the echo signal phase and the distance gate of the echo corresponding to the spurious scattering points under the corresponding computational task.

[0021] Based on the echo signal phase, the distance gate of the echo, and the amplitude-weighted scattering coefficient corresponding to the spurious scattering point under the corresponding computation task, the modulation coefficients corresponding to the spurious scattering point under the corresponding computation task are determined.

[0022] Optionally, based on the beam illumination range, pre-stored azimuth weighting factor tables and range weighting factor tables, and the scattering cross-section data of the spurious scattering points under the corresponding calculation task, the amplitude-weighted scattering coefficients corresponding to the spurious scattering points under the corresponding calculation task are determined, including:

[0023] The antenna angle information of the synthetic aperture radar is determined based on the beam illumination range;

[0024] The azimuth weighting factor corresponding to the antenna angle information is found in the azimuth weighting factor table and used as the target azimuth weighting factor. The range weighting factor corresponding to the antenna angle information is found in the range weighting factor table and used as the target range weighting factor.

[0025] Determine the target amplitude weighting factor corresponding to the spurious scattering point under the corresponding calculation task based on the target azimuth weighting factor and the target range weighting factor;

[0026] The scattering cross-section data of the spurious scattering points under the corresponding computational task are weighted by the target amplitude weighting factor corresponding to the spurious scattering points under the corresponding computational task, so as to obtain the amplitude weighted scattering coefficients corresponding to the spurious scattering points under the corresponding computational task.

[0027] Optionally, based on the baseband signal and the modulation coefficients corresponding to each spurious scattering point, a deception jamming signal corresponding to the intermediate frequency radar signal is generated, including:

[0028] Determine the baseband signal corresponding to the intermediate frequency radar signal;

[0029] The baseband signal and the modulation coefficients corresponding to each false scattering point are convolved to obtain the deception jamming signal corresponding to the intermediate frequency radar signal.

[0030] Optionally, based on the control parameters, a jamming signal corresponding to the intermediate frequency radar signal is generated, including:

[0031] Obtain the frequency points of the intermediate frequency radar signal;

[0032] A point-frequency signal is generated based on the frequency of the intermediate frequency radar signal;

[0033] Generate frequency control words and / or phase control words based on control parameters;

[0034] Based on the frequency control word and / or phase control word, and the spot frequency signal, generate the initial interference signal corresponding to the intermediate frequency radar signal;

[0035] The initial interference signal is pulse-modulated, and the resulting pulse interference signal is used as the suppression interference signal corresponding to the intermediate frequency radar signal.

[0036] Optionally, the initial interference signal may include one or more of the following signals: a frequency sweep signal, a noise frequency modulation signal, a noise phase modulation signal, and a noise amplitude modulation signal.

[0037] Optionally, based on the frequency control word and / or phase control word, and the spot frequency signal, an initial interference signal corresponding to the intermediate frequency radar signal is generated, including:

[0038] The frequency of the point frequency signal is modulated by the frequency control word to obtain the sweep frequency signal and / or the noise frequency modulation signal;

[0039] And / or,

[0040] The phase of the point frequency signal is modulated by the phase control word to obtain the noise phase-modulated signal;

[0041] And / or,

[0042] A noise amplitude-modulated signal is obtained by amplitude modulation of a point frequency signal using a white noise signal. The white noise signal is obtained by filtering the white noise generated by the white noise generator through a preset low-pass filter.

[0043] Optionally, a frequency control word is generated based on control parameters, including:

[0044] If the control parameters include the first parameter, a sawtooth frequency control word is generated based on the first parameter.

[0045] When the control parameters include a second parameter, a triangular frequency control word is generated based on the second parameter.

[0046] When the control parameters include a third parameter, a sinusoidal frequency control word is generated based on the third parameter.

[0047] If the control parameters include a fourth parameter, a noise frequency control word is generated based on the fourth parameter.

[0048] An active composite jamming system for synthetic aperture radar includes: a baseband subsystem, a radio frequency subsystem, and a control and software subsystem for implementing any of the above methods;

[0049] The radio frequency (RF) subsystem is used to acquire relevant parameters of the RF radar signal to be interfered with, and to process the RF radar signal into an intermediate frequency (IF) radar signal based on the relevant parameters of the RF radar signal.

[0050] The control and software subsystem is used to acquire control parameters and radar-related parameters. Among them, radar-related parameters refer to the relevant parameters of the synthetic aperture radar that transmits intermediate frequency radar signals.

[0051] The baseband subsystem is used to call the digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) to calculate the modulation coefficients corresponding to each false scattering point based on the pre-downloaded deception template and radar-related parameters. Based on the intermediate frequency (IF) radar signal and the modulation coefficients corresponding to each false scattering point, it generates the deception jamming signal corresponding to the IF radar signal. Based on the control parameters, it generates the suppression jamming signal corresponding to the IF radar signal. Based on the deception jamming signal and the suppression jamming signal corresponding to the IF radar signal, it determines the composite jamming signal corresponding to the IF radar signal.

[0052] As can be seen from the above technical solution, the active composite jamming method for synthetic aperture radar provided in this application obtains the baseband signal, radar-related parameters, and control parameters corresponding to the intermediate frequency (IF) radar signal to be jammed. It then calls a digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) to calculate the modulation coefficients corresponding to each false scattering point based on pre-downloaded deception templates and radar-related parameters. Based on the IF radar signal and the modulation coefficients corresponding to each false scattering point, a deception jamming signal corresponding to the IF radar signal is generated. Based on the control parameters, a suppression jamming signal corresponding to the IF radar signal is generated. Finally, based on the deception jamming signal and the suppression jamming signal, the composite jamming signal corresponding to the IF radar signal is determined. This application can obtain a composite jamming signal with better jamming effect. Compared with a single suppression jamming signal, the composite jamming signal has lower power, making the jammer's location less likely to be exposed, and the jammer's cost is lower. Furthermore, this application adopts a DSP and FPGA signal processing architecture, effectively improving the system's computational performance and ensuring the real-time performance of the system simulation. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0054] Figure 1A flowchart illustrating the active composite jamming method for synthetic aperture radar provided in this application embodiment;

[0055] Figure 2 This is a block diagram illustrating the implementation principle of image deception interference provided in the embodiments of this application.

[0056] Figure 3 This is a block diagram illustrating the implementation principle of noise suppression interference provided in the embodiments of this application;

[0057] Figure 4 A schematic diagram of the structure of an active composite jamming system for synthetic aperture radar provided in an embodiment of this application;

[0058] Figure 5 A schematic diagram of the structure of an active composite jamming device for synthetic aperture radar provided in an embodiment of this application;

[0059] Figure 6 This is a hardware structure block diagram of an active composite jamming device for synthetic aperture radar provided in an embodiment of this application. Detailed Implementation

[0060] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0061] This application provides an active composite jamming method for synthetic aperture radar (SAR), which can be applied to baseband subsystems. The following embodiments will provide a detailed description of the active composite jamming method for SAR provided in this application.

[0062] Please see Figure 1 This document illustrates a flowchart of an active composite jamming method for synthetic aperture radar provided in an embodiment of this application. The active composite jamming method for synthetic aperture radar may include:

[0063] Step S101: Obtain the intermediate frequency radar signal to be jammed, radar-related parameters, and control parameters.

[0064] Optionally, the baseband subsystem can obtain intermediate frequency radar signals from the radio frequency subsystem. After obtaining the intermediate frequency radar signals, they can be converted into digital intermediate frequency radar signals through an AD (analogue-to-digital conversion) module, so that the following deception jamming signals can be obtained based on the digital intermediate frequency radar signals.

[0065] Optionally, this step can send radar-related parameters and control parameters to the baseband subsystem via the control and software subsystem. Here, radar-related parameters refer to the relevant parameters of the synthetic aperture radar that transmits intermediate frequency radar signals, and control parameters are used to generate jamming signals.

[0066] Optionally, radar-related parameters include, but are not limited to, the following parameters: the aircraft position and speed information of the synthetic aperture radar, and the beamwidth of the synthetic aperture radar.

[0067] Step S102: The digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) are invoked to calculate the modulation coefficients corresponding to each false scattering point based on the pre-downloaded deception template and radar-related parameters.

[0068] Here, the deception template includes multiple spurious scattering points, and the baseband subsystem includes a DSP and multiple FPGA computing boards, each with one or more FPGA chips. This step can utilize the DSP and multiple FPGA computing boards to calculate the modulation coefficients corresponding to each spurious scattering point.

[0069] Since the radar signal to be jammed transmitted by synthetic aperture radar is a pulse signal, this step calculates the modulation coefficient by calling the DSP and FPGA computing board, so that even in a large SAR scene (a scene where the deception template contains a large number of false scattering points, such as a scene with millions or even tens of millions of false scattering points), the calculation result can still be completed within a single pulse repetition period.

[0070] Optionally, the modulation coefficients in this step include the amplitude, delay, and phase corresponding to the spurious scattering points.

[0071] Step S103: Generate a deception jamming signal corresponding to the intermediate frequency radar signal based on the modulation coefficients corresponding to each false scattering point and the intermediate frequency radar signal.

[0072] Here, deception jamming signals are used to create false scenes in radar images to achieve the purpose of deception jamming.

[0073] Optionally, the step of "generating a deception jamming signal corresponding to the intermediate frequency radar signal based on the baseband signal and the modulation coefficients corresponding to each false scattering point" may include: determining the baseband signal corresponding to the intermediate frequency radar signal, and performing convolution processing on the baseband signal and the modulation coefficients corresponding to each false scattering point to obtain the deception jamming signal corresponding to the intermediate frequency radar signal. It is worth noting that the intermediate frequency radar signal in this step is in digital form.

[0074] Optionally, the process of "determining the baseband signal corresponding to the intermediate frequency radar signal" may include: performing instantaneous frequency measurement and digital down-conversion processing on the intermediate frequency radar signal to obtain the baseband signal corresponding to the intermediate frequency radar signal.

[0075] Accordingly, after obtaining the deception interference signal, this step can perform digital up-conversion processing on the deception interference signal to obtain the final deception interference signal, so that the composite interference signal can be determined based on the final deception interference signal.

[0076] Step S104: Generate a suppression jamming signal corresponding to the intermediate frequency radar signal based on the control parameters.

[0077] In this step, noise suppression interference waveforms can be generated digitally based on control parameters. Different control parameters result in different forms of the generated suppression interference signal. For example, the suppression interference signal may include: radio frequency noise, noise amplitude modulation, noise frequency modulation, noise phase modulation, and frequency sweep noise.

[0078] Step S105: Determine the composite interference signal corresponding to the intermediate frequency radar signal based on the deception interference signal and the suppression interference signal corresponding to the intermediate frequency radar signal.

[0079] The step of "determining the composite jamming signal corresponding to the intermediate frequency radar signal based on the deception jamming signal and the suppression jamming signal corresponding to the intermediate frequency radar signal" can be implemented in several ways. In one possible implementation, this step can perform weighted modulation on the deception jamming signal and the suppression jamming signal corresponding to the intermediate frequency radar signal to obtain the composite jamming signal corresponding to the intermediate frequency radar signal.

[0080] It should be noted that the above implementation is merely an example and is not intended to limit this application. For example, this application may also add the amplitude and phase of the deception jamming signal and the suppression jamming signal corresponding to the intermediate frequency radar signal to obtain the composite jamming signal corresponding to the intermediate frequency radar signal.

[0081] In this step, the composite interference signal obtained by the baseband subsystem is an intermediate frequency (IF) digital signal. Optionally, this step can use a digital-to-analog (DA) module to perform digital-to-analog conversion on the composite interference signal to obtain an IF analog composite interference signal. The IF analog composite interference signal is then sent to the radio frequency (RF) subsystem, which performs power adjustment, up-conversion processing, and power amplifier control on the IF analog composite interference signal. After these processes, the RF subsystem converts the IF analog composite interference signal into RF form and feeds it back to the synthetic aperture radar (SAR), thereby interfering with the SAR.

[0082] The active composite jamming method for synthetic aperture radar (SAR) provided in this application acquires the baseband signal, radar-related parameters, and control parameters corresponding to the intermediate frequency (IF) radar signal to be jammed. It then calls upon a digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) to calculate the modulation coefficients corresponding to each false scattering point based on pre-downloaded deception templates and radar-related parameters. Based on the IF radar signal and the modulation coefficients corresponding to each false scattering point, a deception jamming signal corresponding to the IF radar signal is generated. Based on the control parameters, a suppression jamming signal corresponding to the IF radar signal is generated. Finally, based on the deception jamming signal and the suppression jamming signal, the composite jamming signal corresponding to the IF radar signal is determined. This application can obtain a composite jamming signal with better jamming effect. Compared to a single suppression jamming signal, the composite jamming signal has lower power, making the jammer's location less likely to be exposed, and the jammer's cost is lower. Furthermore, this application adopts a DSP and FPGA signal processing architecture, effectively improving the system's computational performance and ensuring the real-time performance of the system simulation.

[0083] The following embodiment describes the process of "step S102, calling the digital signal processor (DSP) and multiple field-programmable gate array (FPGA) computing boards to calculate the modulation coefficients corresponding to each false scattering point based on the pre-downloaded deception template and radar-related parameters".

[0084] In this embodiment, the DSP board is mainly responsible for the task allocation and parameter calculation of multiple FPGA computing boards (multiple FPGA computing boards form an FPGA computing array). The FPGA computing board is the core of the imaging radar echo simulation and is used to calculate the modulation coefficients corresponding to the false scattering points under the corresponding computing tasks.

[0085] Specifically, the aforementioned radar-related parameters include the aircraft position and speed information of the synthetic aperture radar. Therefore, the process of "step S102, calling the digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) to calculate the modulation coefficients corresponding to each false scattering point based on the pre-downloaded deception template and radar-related parameters" can include:

[0086] Step A1: Call the DSP to calculate the beam illumination range of the synthetic aperture radar based on the radar-related parameters, and based on the radar beam illumination range, assign the task of calculating the modulation coefficients corresponding to multiple false scattering points in the deception template to multiple FPGA computing boards.

[0087] In this step, the DSP can allocate computing tasks to each parallel processing unit (i.e., FPGA computing board) in the FPGA computing array according to the radar beam illumination range, and the DSP can configure radar-related parameters for the FPGA computing array.

[0088] For example, an FPGA computing array contains 10 FPGA computing boards. Assuming the deception template contains 1 million false scattering points, the DSP can assign 100,000 false scattering points to each of the 10 FPGA computing boards according to the radar beam illumination range, each corresponding to a modulation coefficient calculation task.

[0089] Step A2: Based on the carrier's position and speed information, call multiple FPGA computing boards to determine the distances between the false scattering points under the computing tasks of the multiple FPGA computing boards and the antenna phase center of the synthetic aperture radar, and use these distances as the scattering point distances corresponding to the false scattering points under the computing tasks of the multiple FPGA computing boards.

[0090] See Figure 2 As shown, in this step, the FPGA computing board can determine the distance between the spurious scattering points and the antenna phase center of the synthetic aperture radar (SAR) based on the aircraft position information of the SAR and the three-dimensional geometric relationship constructed from the SAR platform and the ground scattering scene. For ease of subsequent description, the calculated distance is used as the scattering point distance. It is understood that the positions of different spurious scattering points may be different, and therefore the scattering point distance corresponding to each spurious scattering point may be different.

[0091] Step A3: Call multiple FPGA computing boards to extract the scattering cross-section data of the false scattering points under the corresponding computing task based on the beam illumination range.

[0092] In this step, the FPGA chip on each FPGA computing board can extract the scattering cross section (RCS) data of the spurious scattering points for the corresponding computing task in real time according to the radar beam illumination range. Here, each spurious scattering point has its own corresponding RCS data.

[0093] Step A4: Call multiple FPGA computing boards to determine the amplitude-weighted scattering coefficients corresponding to the false scattering points under the corresponding computing task, based on the beam illumination range, the pre-stored azimuth weighting factor table and range weighting factor table, and the scattering cross-section data of the false scattering points under the corresponding computing task.

[0094] Optionally, the process of "determining the amplitude-weighted scattering coefficients corresponding to the spurious scattering points under the corresponding calculation task based on the beam illumination range, the pre-stored azimuth weighting factor table and range weighting factor table, and the scattering cross-section data of the spurious scattering points under the corresponding calculation task" may include the following steps A41 to A44:

[0095] Step A41: Determine the antenna angle information of the synthetic aperture radar based on the beam illumination range.

[0096] Optionally, the antenna angle information for synthetic aperture radar includes elevation and azimuth angles.

[0097] Step A42: Find the azimuth weighting factor corresponding to the antenna angle information in the azimuth weighting factor table and use it as the target azimuth weighting factor. Also, find the range weighting factor corresponding to the antenna angle information in the range weighting factor table and use it as the target range weighting factor.

[0098] In this step, in order to reduce the storage of data tables, the antenna amplitude weighting factor is characterized by azimuth weighting factor and range weighting factor. Based on this, the application pre-stores the azimuth weighting factor table and the range weighting factor table.

[0099] The azimuth weighting factor table contains the correspondence between the antenna angle information (including elevation and azimuth angles) of the synthetic aperture radar and the azimuth weighting factor, while the range weighting factor table contains the correspondence between the antenna angle information of the synthetic aperture radar and the range weighting factor.

[0100] See Figure 2 As shown, a block diagram illustrating the implementation principle of image deception jamming is presented. After calculating the antenna angle information of the synthetic aperture radar in the aforementioned steps, this step can obtain the target azimuth weighting factor and the target range weighting factor by looking up a table.

[0101] Step A43: Determine the target amplitude weighting factor corresponding to the spurious scattering point under the corresponding calculation task based on the target azimuth weighting factor and the target range weighting factor.

[0102] Step A44: Based on the target amplitude weighting factor corresponding to the false scattering points under the corresponding calculation task, perform amplitude weighting on the scattering cross section data of the false scattering points under the corresponding calculation task to obtain the amplitude weighted scattering coefficients corresponding to the false scattering points under the corresponding calculation task.

[0103] In this step, in order to accurately simulate the echo amplitude of the scattering point, the updated RCS data needs to be amplitude-weighted by the antenna beam to simulate the influence of the radar antenna on the echo signal.

[0104] like Figure 2 As shown, multiple FPGA computing boards can perform amplitude weighting on the scattering cross-section data of the spurious scattering points under their respective computing tasks according to the target amplitude weighting factor corresponding to the spurious scattering points under their respective computing tasks, so as to obtain the amplitude weighted scattering coefficients corresponding to the spurious scattering points under their respective computing tasks.

[0105] Step A5: Call multiple FPGA computing boards to calculate the modulation coefficients corresponding to the spurious scattering points under the corresponding computing tasks based on the scattering point distance and amplitude weighted scattering coefficients, so as to obtain the modulation coefficients corresponding to each spurious scattering point.

[0106] In this embodiment, before simulation, the deception template can be downloaded to the memory corresponding to multiple FPGA computing boards. After the multiple FPGA computing boards calculate the scattering point distance and amplitude-weighted scattering coefficients corresponding to the fake scattering points under the corresponding computing tasks, the FPGA chips on the multiple FPGA computing boards can calculate the modulation coefficients corresponding to the virtual scattering points under their respective computing tasks. After the multiple FPGA computing boards have completed the calculations, this embodiment can converge the modulation coefficients calculated by the FPGA chips on the same FPGA computing board and the FPGA chips on different FPGA computing boards to obtain the modulation coefficients corresponding to all scattering points within the radar illumination range.

[0107] In an alternative embodiment, see Figure 2 As shown, the process of "calculating the modulation coefficients corresponding to the spurious scattering points under the corresponding computational task based on the scattering point distance and amplitude-weighted scattering coefficients corresponding to the spurious scattering points under the corresponding computational task" can include the following steps A51 to A52:

[0108] Step A51: Based on the distances of the scattering points corresponding to the spurious scattering points under the corresponding calculation task, determine the echo signal phase and echo distance gate corresponding to the spurious scattering points under the corresponding calculation task.

[0109] In this step, multiple FPGA computing boards can determine the echo signal phase and range gate corresponding to the spurious scattering points under their respective computing tasks, based on the scattering point distances to those spurious scattering points. Specifically, this process includes: multiple FPGA computing boards determining the range gate of the echo from the spurious scattering points under their respective computing tasks, based on the scattering point distances to those spurious scattering points. Furthermore, multiple FPGA computing boards can determine the echo phase corresponding to the spurious scattering points under their respective computing tasks, based on the scattering point distances to those spurious scattering points.

[0110] Step A52: Determine the modulation coefficients corresponding to the spurious scattering points under the corresponding calculation tasks based on the echo signal phase, the distance gate of the echo, and the amplitude-weighted scattering coefficients.

[0111] In this step, the process of "determining the modulation coefficients corresponding to the false scattering points under the corresponding computational task based on the echo signal phase, the range gate of the echo, and the amplitude-weighted scattering coefficients of the false scattering points under the corresponding computational task" includes: For each of the multiple FPGA computational boards, the FPGA computational board can accumulate the product of the echo phase and the amplitude-weighted scattering coefficients of each false scattering point at the same range gate under its own computational task to obtain the surface target echo modulation information corresponding to each range gate. Based on the surface target echo modulation information corresponding to each range gate, the surface target echo modulation information corresponding to the false scattering points under the computational task corresponding to the FPGA computational board is determined (here, the surface target echo modulation information is denoted as the modulation coefficient in this embodiment); each FPGA computational board performs calculations according to the above calculation process to obtain the modulation coefficients corresponding to the false scattering points under the computational task corresponding to each FPGA computational board.

[0112] In summary, this embodiment uses an FPGA high-performance computing board and a DSP information preprocessing board to realize the real-time calculation of the modulation coefficient for image deception interference, which enables the modulation coefficient to be completed within a single pulse repetition period, effectively improving the system's computing performance and meeting the real-time requirements.

[0113] One embodiment of this application describes the process of "step S104: generating a suppression jamming signal corresponding to the intermediate frequency radar signal according to the control parameters".

[0114] Step B1: Obtain the frequency point of the intermediate frequency radar signal.

[0115] Step B2: Generate a point frequency signal based on the frequency of the intermediate frequency radar signal.

[0116] See Figure 3 As shown, this step can generate a point frequency signal in the point frequency signal DDS module based on the frequency of the intermediate frequency radar signal.

[0117] Step B3: Generate frequency control word and / or phase control word based on control parameters.

[0118] In this step, different control parameters result in different frequency control words. Optionally, the process of "generating frequency control words based on control parameters" includes: generating a sawtooth frequency control word based on the first parameter when the control parameters include a first parameter; generating a triangular frequency control word based on the second parameter when the control parameters include a second parameter; generating a sinusoidal frequency control word based on the third parameter when the control parameters include a third parameter; and generating a noise frequency control word based on the fourth parameter when the control parameters include a fourth parameter.

[0119] For example, see Figure 3As shown, a sawtooth frequency control word is generated when parameter 1 is input, a triangular frequency control word is generated when parameter 2 is input, a sine frequency control word is generated when parameter 3 is input, and a noise frequency control word (which can be a white noise frequency control word) is generated when parameter 4 is input.

[0120] Step B4: Generate the initial interference signal corresponding to the intermediate frequency radar signal based on the frequency control word and / or phase control word, as well as the point frequency signal.

[0121] Optional, such as Figure 3 As shown, the initial interference signal includes one or more of the following signals: frequency sweep signal, noise frequency modulation signal, noise phase modulation signal (…). Figure 3 (not shown) and noise amplitude modulation signal.

[0122] Based on this, the process of "generating the initial interference signal corresponding to the intermediate frequency radar signal according to the frequency control word and / or phase control word, and the point frequency signal" can include: frequency modulation of the point frequency signal through the frequency control word to obtain a swept frequency signal and / or a noise frequency modulation signal; and / or phase modulation of the point frequency signal through the phase control word to obtain a noise phase modulation signal; and / or amplitude modulation of the point frequency signal through a white noise signal to obtain a noise amplitude modulation signal.

[0123] Here, when the frequency control word is a sawtooth frequency control word, the sweep signal is specifically a sawtooth wave sweep signal; when the frequency control word is a triangular frequency control word, the sweep signal is specifically a triangular wave sweep signal; when the frequency control word is a sine wave frequency control word, the sweep signal is specifically a sine wave sweep signal; and when the frequency control word is a noise frequency control word, the sweep signal is specifically a noise sweep signal.

[0124] The white noise signal is obtained by filtering the white noise generated by the white noise generator through a preset low-pass filter. The bandwidth of the white noise signal is determined according to the filter coefficients of the low-pass filter.

[0125] Step B5: Pulse modulate the initial interference signal to obtain the pulse interference signal as the suppression interference signal corresponding to the intermediate frequency radar signal.

[0126] For example, this step can pulse-modulate the swept frequency signal, the noise frequency modulation signal, the noise amplitude modulation signal, and the noise phase modulation signal, and the resulting pulse interference signal can be used as the suppression interference signal corresponding to the intermediate frequency radar signal.

[0127] In summary, this embodiment can obtain various forms of suppressed interference signals, thus improving the interference effect.

[0128] This application also provides an active composite jamming system for synthetic aperture radar, see [link to relevant documentation]. Figure 4As shown, the active composite jamming system 40 of the synthetic aperture radar includes a baseband subsystem 401, a radio frequency subsystem 402, and a control and software subsystem 403 provided in any of the above embodiments.

[0129] In this embodiment, the radio frequency subsystem 402 is used to acquire relevant parameters of the radio frequency radar signal to be interfered with, and to process the radio frequency radar signal into an intermediate frequency radar signal based on the relevant parameters of the radio frequency radar signal.

[0130] The control and software subsystem 403 is used to acquire control parameters and radar-related parameters, where radar-related parameters refer to the parameters of the synthetic aperture radar that transmits intermediate frequency radar signals.

[0131] The baseband subsystem 401 is used to call the digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) to calculate the modulation coefficients corresponding to each false scattering point based on the pre-downloaded deception template and radar-related parameters. Based on the intermediate frequency (IF) radar signal and the modulation coefficients corresponding to each false scattering point, it generates a deception jamming signal corresponding to the IF radar signal. Based on the control parameters, it generates a suppression jamming signal corresponding to the IF radar signal. Based on the deception jamming signal and the suppression jamming signal corresponding to the IF radar signal, it determines the composite jamming signal corresponding to the IF radar signal. Here, the composite jamming signal is the IF signal.

[0132] Optionally, the baseband subsystem 401 includes at least one Digital Radio Frequency Memory (DRFM) board, each DRFM board corresponding to one signal channel, for example, see [link to relevant documentation]. Figure 4 As shown, two DRFM boards are illustrated. Each DRFM board can implement the aforementioned processing steps S101 to S105. Of course, either DRFM board can generate only a deception interference signal or only a suppression interference signal. This application does not specifically limit this.

[0133] It should be noted that when the baseband subsystem 401 contains multiple DRFM boards, i.e. multiple signal channels, the signal types simulated by the multiple signal channels provided in this application can be set independently to generate composite interference signals that simultaneously have suppression and deception characteristics.

[0134] Optional, see Figure 4As shown, the RF subsystem 402 includes a down-conversion and power adjustment module, an up-conversion and power adjustment module, and a frequency synthesizer module. The down-conversion and power adjustment module is used to adjust the power of the received radar RF signal (i.e., the intermediate frequency radar signal) and perform multi-stage down-conversion to the intermediate frequency baseband signal, so that the frequency range and power of the baseband signal can meet the requirements of the DRFM channel. The up-conversion and power adjustment module is used to perform up-conversion and dynamic power control on the dual-channel intermediate frequency echo signal output by the DRFM (in this application, the intermediate frequency echo signal specifically refers to the intermediate frequency composite interference signal; of course, the intermediate frequency echo signal can also be the intermediate frequency suppression interference signal or the intermediate frequency deception interference signal) to obtain the RF echo signal output to the radar. The frequency synthesizer module is used to obtain the clock signal required for RF up-conversion and down-conversion local oscillator and baseband operation based on the radar reference frequency.

[0135] Optionally, the control and software subsystem 403 mainly consists of interface control and display software, a general control board, and interference model software. The interference model software calculates various types of interference information calculation parameters (i.e., aircraft position and speed information) required by the baseband subsystem based on the parameters set in the interface, and sends the interference information calculation parameters to the baseband unit. The general control board is used to receive control commands and parameters and control other subsystems.

[0136] In summary, this application provides an active composite jamming system for synthetic aperture radar, which has the following advantages:

[0137] First, from the perspective of radar countermeasures, there are multiple forms of interference in the complex interference environment. Traditional anti-jamming methods are not very effective. By making full use of the advantages of different interference patterns and taking the best of both worlds, we can improve our countermeasures capabilities, achieve better interference effects on enemy SAR, and disrupt their SAR reconnaissance equipment.

[0138] Second, it provides a basis for researching anti-jamming technologies for similar systems. Radar jamming and anti-jamming technologies need to be developed in tandem. While preventing the monitoring of sensitive areas or even the detection and identification of high-value targets, it is also necessary to obtain accurate strategic intelligence. The emergence of new jamming technologies will drive the development of anti-jamming technologies.

[0139] Third, the FPGA+DSP signal processing architecture is adopted, which effectively improves the system's computing performance and ensures the real-time performance of the system simulation.

[0140] This application also provides an active composite jamming device for synthetic aperture radar. The active composite jamming device for synthetic aperture radar provided in this application is described below. The active composite jamming device for synthetic aperture radar described below can be referred to in correspondence with the active composite jamming method for synthetic aperture radar described above.

[0141] Please see Figure 5 This illustration shows a schematic diagram of the structure of an active composite jamming device for synthetic aperture radar provided in an embodiment of this application, as shown below. Figure 5 As shown, the active composite jamming device of the synthetic aperture radar may include: a basic information acquisition module 501, a modulation coefficient calculation module 502, a deception jamming signal generation module 503, a suppression jamming signal generation module 504, and a composite jamming signal determination module 505.

[0142] The basic information acquisition module 501 is used to acquire the intermediate frequency radar signal to be jammed, radar related parameters and control parameters. Among them, the radar related parameters refer to the related parameters of the synthetic aperture radar that transmits the intermediate frequency radar signal.

[0143] The modulation coefficient calculation module 502 is used to call the digital signal processor (DSP) and multiple field-programmable gate array (FPGA) calculation boards to calculate the modulation coefficients corresponding to each false scattering point based on the pre-downloaded deception template and radar-related parameters.

[0144] The deception jamming signal generation module 503 is used to generate a deception jamming signal corresponding to the intermediate frequency radar signal based on the modulation coefficients corresponding to each false scattering point.

[0145] The jamming signal generation module 504 is used to generate a jamming signal corresponding to the intermediate frequency radar signal based on the control parameters.

[0146] The composite interference signal determination module 505 is used to determine the composite interference signal corresponding to the intermediate frequency radar signal based on the deception interference signal and the suppression interference signal corresponding to the intermediate frequency radar signal.

[0147] In summary, the working principle of the active composite jamming device for synthetic aperture radar disclosed in this embodiment is the same as that of the active composite jamming method for synthetic aperture radar disclosed in the above embodiments, and will not be repeated here.

[0148] This application also provides an active composite jamming device for synthetic aperture radar. Optionally, Figure 6 The hardware block diagram of the active composite jamming device for synthetic aperture radar is shown, with reference to... Figure 6 The hardware structure of the active composite jamming device of the synthetic aperture radar may include: at least one processor 601, at least one communication interface 602, at least one memory 603 and at least one communication bus 604.

[0149] In this embodiment of the application, the number of processor 601, communication interface 602, memory 603 and communication bus 604 is at least one, and processor 601, communication interface 602 and memory 603 communicate with each other through communication bus 604.

[0150] The processor 601 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention.

[0151] The memory 603 may include high-speed RAM, and may also include non-volatile memory, such as at least one disk storage device;

[0152] The memory 603 stores a program, and the processor 601 can call the program stored in the memory 603. The program is used for:

[0153] Acquire the intermediate frequency radar signal to be jammed, radar-related parameters, and control parameters. Among them, the radar-related parameters refer to the related parameters of the synthetic aperture radar that transmits the intermediate frequency radar signal.

[0154] The digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) are invoked to calculate the modulation coefficients corresponding to each false scattering point based on the pre-downloaded deception template and radar-related parameters.

[0155] Based on the modulation coefficients corresponding to the intermediate frequency radar signal and each false scattering point, a deception jamming signal corresponding to the intermediate frequency radar signal is generated.

[0156] Based on the control parameters, generate the suppression jamming signal corresponding to the intermediate frequency radar signal;

[0157] Based on the deception jamming signal and the suppression jamming signal corresponding to the intermediate frequency radar signal, the composite jamming signal corresponding to the intermediate frequency radar signal is determined.

[0158] Optionally, the refined and extended functions of the program can be found in the description above.

[0159] This application also provides a readable storage medium storing a computer program thereon, which, when executed by a processor, implements the active composite jamming method for synthetic aperture radar as described above.

[0160] Optionally, the refined and extended functions of the program can be found in the description above.

[0161] Finally, it should be noted that in this document, relational terms such as "second" and "etc." are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0162] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0163] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An active composite jamming method for synthetic aperture radar, characterized in that, Applied to baseband subsystems, including: The intermediate frequency radar signal to be jammed, radar-related parameters, and control parameters are acquired, wherein the radar-related parameters refer to the related parameters of the synthetic aperture radar that transmits the intermediate frequency radar signal; The digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) are invoked to calculate the modulation coefficients corresponding to each false scattering point based on the pre-downloaded deception template and the radar-related parameters. Based on the intermediate frequency radar signal and the modulation coefficients corresponding to each false scattering point, a deception jamming signal corresponding to the intermediate frequency radar signal is generated. Based on the control parameters, a suppression jamming signal corresponding to the intermediate frequency radar signal is generated; Based on the deception jamming signal and the suppression jamming signal corresponding to the intermediate frequency radar signal, determine the composite jamming signal corresponding to the intermediate frequency radar signal; The radar-related parameters include the aircraft position and speed information of the synthetic aperture radar; The process involves calling a digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) to calculate the modulation coefficients corresponding to each false scattering point based on a pre-downloaded deception template and the radar-related parameters, including: The DSP is invoked to calculate the beam illumination range of the synthetic aperture radar based on the radar-related parameters, and based on the radar beam illumination range, the task of calculating the modulation coefficients corresponding to multiple false scattering points in the deception template is assigned to the multiple FPGA computing boards. The multiple FPGA computing boards are invoked to determine the distances between the false scattering points under the computing tasks corresponding to the multiple FPGA computing boards and the antenna phase center of the synthetic aperture radar, based on the carrier position and speed information. These distances are used as the scattering point distances corresponding to the false scattering points under the computing tasks corresponding to the multiple FPGA computing boards. The multiple FPGA computing boards are invoked to extract the scattering cross-section data of the false scattering points under the corresponding computing task based on the beam illumination range; The multiple FPGA computing boards are invoked to determine the amplitude-weighted scattering coefficients corresponding to the false scattering points under the corresponding computing task based on the beam illumination range, the pre-stored azimuth weighting factor table and range weighting factor table, and the scattering cross-section data of the false scattering points under the corresponding computing task. The multiple FPGA computing boards are invoked to calculate the modulation coefficients corresponding to the spurious scattering points under the corresponding computing tasks based on the scattering point distance and amplitude-weighted scattering coefficients, so as to obtain the modulation coefficients corresponding to each spurious scattering point.

2. The active composite jamming method for synthetic aperture radar according to claim 1, characterized in that, The step of calculating the modulation coefficients corresponding to the spurious scattering points under the corresponding computational task based on the scattering point distance and amplitude-weighted scattering coefficients of the spurious scattering points under the corresponding computational task includes: Based on the distances of the scattering points corresponding to the spurious scattering points under the corresponding computational task, determine the echo signal phase and the distance gate of the echo corresponding to the spurious scattering points under the corresponding computational task. Based on the echo signal phase, the distance gate of the echo, and the amplitude-weighted scattering coefficient corresponding to the spurious scattering point under the corresponding computation task, the modulation coefficients corresponding to the spurious scattering point under the corresponding computation task are determined.

3. The active composite jamming method for synthetic aperture radar according to claim 1, characterized in that, The step of determining the amplitude-weighted scattering coefficients corresponding to the spurious scattering points under the corresponding calculation task based on the beam illumination range, the pre-stored azimuth weighting factor table and range weighting factor table, and the scattering cross-section data of the spurious scattering points under the corresponding calculation task includes: The antenna angle information of the synthetic aperture radar is determined based on the beam illumination range; The azimuth weighting factor corresponding to the antenna angle information is found in the azimuth weighting factor table and used as the target azimuth weighting factor. The range weighting factor corresponding to the antenna angle information is found in the range weighting factor table and used as the target range weighting factor. Based on the target azimuth weighting factor and the target range weighting factor, determine the target amplitude weighting factor corresponding to the spurious scattering point under the corresponding calculation task; The scattering cross-section data of the spurious scattering points under the corresponding computational task are weighted by the target amplitude weighting factor corresponding to the spurious scattering points under the corresponding computational task, so as to obtain the amplitude weighted scattering coefficients corresponding to the spurious scattering points under the corresponding computational task.

4. The active composite jamming method for synthetic aperture radar according to claim 1, characterized in that, The step of generating a deception jamming signal corresponding to the intermediate frequency radar signal based on the intermediate frequency radar signal and the modulation coefficients corresponding to each false scattering point includes: Determine the baseband signal corresponding to the intermediate frequency radar signal; The baseband signal and the modulation coefficients corresponding to each false scattering point are convolved to obtain the deception jamming signal corresponding to the intermediate frequency radar signal.

5. The active composite jamming method for synthetic aperture radar according to claim 1, characterized in that, The step of generating the suppression jamming signal corresponding to the intermediate frequency radar signal according to the control parameters includes: Obtain the frequency point of the intermediate frequency radar signal; A point-frequency signal is generated based on the frequency of the intermediate frequency radar signal; Generate a frequency control word and / or a phase control word based on the control parameters; Based on the frequency control word and / or the phase control word, and the point frequency signal, an initial interference signal corresponding to the intermediate frequency radar signal is generated; The initial interference signal is pulse-modulated, and the resulting pulse interference signal is used as the suppression interference signal corresponding to the intermediate frequency radar signal.

6. The active composite jamming method for synthetic aperture radar according to claim 5, characterized in that, The initial interference signal includes one or more of the following signals: frequency sweep signal, noise frequency modulation signal, noise phase modulation signal, and noise amplitude modulation signal.

7. The active composite jamming method for synthetic aperture radar according to claim 6, characterized in that, The step of generating the initial interference signal corresponding to the intermediate frequency radar signal based on the frequency control word and / or the phase control word, and the point frequency signal, includes: The frequency control word is used to modulate the frequency of the point frequency signal to obtain a swept frequency signal and / or a noise frequency modulated signal; And / or, The phase control word is used to modulate the phase of the point frequency signal to obtain a noise phase-modulated signal; And / or, A noise amplitude-modulated signal is obtained by amplitude modulation of the point frequency signal using a white noise signal, wherein the white noise signal is obtained by filtering the white noise generated by the white noise generator through a preset low-pass filter.

8. The active composite jamming method for synthetic aperture radar according to claim 6, characterized in that, The step of generating a frequency control word based on the control parameters includes: If the control parameters include a first parameter, a sawtooth frequency control word is generated based on the first parameter. If the control parameters include a second parameter, a triangular frequency control word is generated based on the second parameter. If the control parameters include a third parameter, a sinusoidal frequency control word is generated based on the third parameter. If the control parameters include a fourth parameter, a noise frequency control word is generated based on the fourth parameter.

9. An active composite jamming system for synthetic aperture radar, characterized in that, include: The baseband subsystem, radio frequency subsystem, and control and software subsystem that implement the method according to any one of claims 1 to 8; The radio frequency subsystem is used to acquire relevant parameters of the radio frequency radar signal to be interfered with, and to process the radio frequency radar signal into an intermediate frequency radar signal based on the relevant parameters of the radio frequency radar signal. The control and software subsystem is used to acquire control parameters and radar-related parameters, wherein the radar-related parameters refer to the parameters of the synthetic aperture radar that transmits the intermediate frequency radar signal. The baseband subsystem is used to call a digital signal processor (DSP) and multiple field-programmable gate arrays (FPGAs) to calculate the modulation coefficients corresponding to each false scattering point based on a pre-downloaded deception template and the radar-related parameters. Based on the intermediate frequency (IF) radar signal and the modulation coefficients corresponding to each false scattering point, it generates a deception jamming signal corresponding to the IF radar signal. Based on the control parameters, it generates a suppression jamming signal corresponding to the IF radar signal. Based on the deception jamming signal and the suppression jamming signal corresponding to the IF radar signal, it determines the composite jamming signal corresponding to the IF radar signal.

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