Multi-target simulation method, device and system for phased array secondary radar system

Abstract

The present invention discloses a multi-target simulation method, device and system for a phased array secondary radar system. The method includes: calculating the maximum number of simulated targets and the minimum distance between simulated targets; calculating, in real time according to the towing azimuth and beam coverage range of the phased array secondary radar system, the phase weighting values corresponding to the simulated targets generated at each azimuth within the coverage range; forming a multi-target control timing sequence based on the interrogation decoding information with the starting moment of the response coding as the reference point; within the response period, controlling the transmitting module to generate a radio frequency signal according to the multi-target control timing sequence, and controlling the beamforming and channel module to process the radio frequency signal to form a multi-target radio frequency signal after multi-channel digital beamforming. The present invention adopts multi-target timing control technology and adaptive digital beamforming technology to realize systematic testing and verification of the multi-target recognition and processing ability of the phased array secondary radar system.

Description

Technical Field

[0001] The present invention belongs to the technical field of secondary radar target simulation, and particularly relates to a multi-target simulation method, device and system for a phased array secondary radar system. Background Art

[0002] A phased array secondary radar is an advanced secondary radar system. Compared with the traditional mechanically scanned secondary radar, the phased array secondary radar has agile inertia-free beam scanning and powerful multi-target processing capabilities, and has been widely used in military, aviation, aerospace and other fields.

[0003] The multi-target simulation technology of the traditional monopulse secondary radar system has been relatively mature and has been widely used in the secondary radar test and verification systems based on the sum-difference three-channel monopulse receiving technology.

[0004] During the development and application process of the phased array secondary radar system, it is also necessary to provide a multi-target simulation environment for system debugging, daily function inspection and training of operators. The multi-target simulation technology for the phased array secondary radar system is an important tool to support the creation of a multi-target environment and the debugging and inspection of the phased array secondary radar system.

[0005] The existing secondary radar target simulation system is only applicable to the traditional mechanically scanned monopulse secondary radar system, and uses single-channel RF signal simulation, which is not applicable to the phased array secondary radar system that adopts new technologies such as antenna array technology, multi-channel reception, and digital beamforming.

[0006] The existing target simulation for the phased array secondary radar system only realizes the simulation of a single responding target, and cannot realize the simulation of the distance, azimuth and code of multiple targets, and cannot systematically test and verify the multi-target recognition and processing capabilities of the phased array secondary radar system. Summary of the Invention

[0007] In order to solve the limitations existing in the existing secondary radar target simulation technology, the present invention provides a multi-target simulation method for a phased array secondary radar system. The present invention adopts multi-target timing control technology and adaptive digital beamforming technology, and realizes the systematic test and verification of the multi-target recognition and processing capabilities of the phased array secondary radar system through the simulation of the distance, azimuth and code of multiple targets.

[0008] The present invention is realized through the following technical solutions:

[0009] A multi-target simulation method for a phased array secondary radar system, comprising:

[0010] Calculating the maximum number of simulated targets and the minimum distance between simulated targets according to the maximum operating distance of the phased array secondary radar system and the delay of the target simulation system;

[0011] According to the towing azimuth and beam coverage of the phased array secondary radar system, calculate in real time the phase weighting values corresponding to the simulated targets generated at each azimuth within the coverage range;

[0012] According to the interrogation decoding information, taking the starting moment of the response coding as the reference point, form a multi-target control time sequence;

[0013] Within the response period, control the transmitting module to generate radio frequency signals according to the multi-target control time sequence, and control the beam forming and channel module to process the radio frequency signals to form multi-channel digital beam formed multi-target radio frequency signals.

[0014] Preferably, the maximum operating distance Rmax of the phased array secondary radar system of the present invention varies according to the different radar platforms used;

[0015] The target simulation system delay includes encoding / decoding processing delay t p , phase shifter switch delay t s and response coding duration t c .

[0016] Preferably, the relationship between the maximum operating distance R max of the present invention and the maximum distance time delay t max satisfies: t max = 2R max / c, where c is the speed of light;

[0017] The maximum number of simulated targets Num max then satisfies: Num max = t max / (t p + t s + t c );

[0018] At this time, the minimum distance R min between the simulated targets then satisfies: R min = (t p + t s + t c )c / 2.

[0019] Preferably, the steps of calculating in real time the phase weighting values corresponding to the simulated targets generated at each azimuth within the coverage range of the present invention specifically include:

[0020] According to the parameters of the phased array antenna-feed system of the measured secondary radar system, calculate the theoretical phase weighting value arrays of each channel at different azimuths relative to the normal of the antenna array surface;

[0021] Obtain the actual antenna pattern of the phased array secondary radar system, and according to the wave position division of the phased array secondary radar, obtain the measured phase weighting value array of each channel of each waveform forming beam.

[0022] Superimpose the measured phase weighting value array of each obtained channel with its corresponding theoretical phase weighting value array, then the phase weighting value array corresponding to the simulated target generated at each azimuth within the coverage of each beam can be obtained.

[0023] According to the simulated target azimuth, combined with the phase weighting value array corresponding to the simulated target generated at each azimuth, allocate corresponding beamforming phase shift control codes for the simulated targets at different azimuths.

[0024] Preferably, before the step of forming the multi-target control timing sequence with the response coding start moment as the reference point according to the interrogation decoding information in the present invention, it further includes:

[0025] By receiving the beam pointing azimuth of the secondary radar system in real time, judge whether the current simulated target is within the antenna beam received in real time to determine whether the target simulation system generates a response signal.

[0026] Preferably, the step of forming the multi-target control timing sequence with the response coding start moment as the reference point according to the interrogation decoding information in the present invention specifically includes:

[0027] Process the secondary radar interrogation signal received by the receiving module to form a decoding success trigger signal, and trigger the generation of response coding;

[0028] Taking the moment when the response coding is generated as the reference point, start coding from the target with the closest distance according to the target distance; this coding process specifically includes:

[0029] According to the phase shift control code, encode each phase shifter in the beamforming and channel module;

[0030] Perform response distance counting, and generate response data coding after the counting is completed;

[0031] Use the above coding process to encode other targets in turn according to the target distance, where the response distance counting starting point of the next target is the time occupied by the simulation of all previous targets.

[0032] Preferably, the step of controlling the beamforming and channel module to process the RF signal in the present invention is specifically:

[0033] First, perform power division processing on the RF signal generated by the transmitting module to multiple RF channels;

[0034] Then perform phase shift respectively, and finally form a multi-target RF signal that can be used for the receiving and processing of the phased array secondary radar system.

[0035] In a second aspect, the present invention provides a multi-target simulation device for a phased array secondary radar system, comprising a first calculation unit, a second calculation unit, a timing generation unit, and a control unit;

[0036] The first calculation unit calculates the maximum number of simulated targets and the minimum distance between simulated targets according to the maximum operating range of the phased array secondary radar system and the delay of the target simulation system;

[0037] The second calculation unit calculates the phase weighting values corresponding to the simulated targets generated at each azimuth within the coverage range in real time according to the pulling azimuth of the phased array secondary radar system and the beam coverage range;

[0038] The timing generation unit forms a multi-target control timing with the starting moment of the response coding as the reference point according to the interrogation decoding information;

[0039] During the response period, the control unit controls the transmitting module to generate a radio frequency signal according to the multi-target control timing, and controls the beamforming and channel module to process the radio frequency signal, and finally forms multiple target signals after multi-channel digital beamforming.

[0040] In a third aspect, the present invention provides a multi-target simulation system for a phased array secondary radar system, comprising a signal processing module, a transmitting module, a receiving module, and a beamforming and channel module;

[0041] The transmitting module, the receiving module, and the beamforming and channel module are all communicatively connected to the signal processing module;

[0042] The signal processing module serves as the main controller of the system and is used to control the transmitting module, the receiving module, and the beamforming and channel module;

[0043] The signal processing module uses the multi-target simulation device as claimed in claim 8 to generate multi-target control serial numbers, and controls the beamforming and channel module to process the radio frequency signal generated by the transmitting module according to the multi-target control timing, so as to form a multi-target radio frequency signal that can be used for receiving and processing by the phased array secondary radar system.

[0044] Preferably, the system of the present invention further comprises a power supply module, a main control computer, and a display;

[0045] The power supply module supplies power to each module in the system;

[0046] The main control computer sends relevant data and control signals to the signal processing module, and receives the processing results uploaded by the signal processing module;

[0047] The display is communicatively connected to the main control computer.

[0048] The present invention has the following advantages and beneficial effects:

[0049] 1. The present invention has strong practicability, flexible construction, strong reconfigurability, and a wide range of application platforms. The present invention is applicable to both phased array secondary radar systems and can also be compatible with traditional mechanically scanned monopulse secondary radar systems.

[0050] 2. The present invention can comprehensively test the receiving channels, signal processing, beam forming and scheduling, multi-target processing and control, target splitting situations, etc. of a phased array secondary radar system, and can be applied to the daily function inspection and operation training of phased array secondary radar systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the drawings:

[0052] Figure 1 is a schematic flow diagram of the simulation method of the present invention.

[0053] Figure 2 is a schematic block diagram of the simulation device of the present invention.

[0054] Figure 3 is a schematic block diagram of the secondary radar system of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0055] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the embodiments and the drawings. The illustrative embodiments and descriptions thereof of the present invention are only used to explain the present invention and do not limit the present invention.

[0056] Embodiment 1

[0057] Existing secondary radar target simulation systems are not applicable to phased array secondary radar systems that adopt new technologies such as antenna array technology, multi-channel reception, and digital beam forming; and the target simulation for phased array secondary radar systems cannot achieve the simulation of the distance, azimuth, and code of multiple targets, and cannot systematically test and verify the multi-target recognition and processing capabilities of phased array secondary radar systems. In view of the above problems, this embodiment proposes a method for multi-target simulation for phased array secondary radar systems. In this embodiment, through the simulation of the distance, azimuth, and code of multiple targets, the multi-target recognition and processing capabilities of phased array secondary radar systems are systematically tested and verified.

[0058] As Figure 1 shown, the method of this embodiment includes:

[0059] Step 1: Calculate the maximum number of simulated targets and the minimum distance between simulated targets according to the maximum operating range of the phased array secondary radar system and the delay of the target simulation system.

[0060] Step 2: Calculate the phase weighting values corresponding to the simulated targets generated at each azimuth within the coverage range in real time according to the towing azimuth and beam coverage range of the phased array secondary radar system.

[0061] Step 3: Based on the interrogation decoding information, form a multi-target control timing sequence with the start time of the response coding as the reference point. Among them, the multi-target control timing sequence includes the distance delay, response azimuth simulation, phase shifter switching time, and response coding of each target.

[0062] Step 4: During the response period, control the transmitting module to generate a radio frequency signal according to the multi-target control timing sequence, control the beamforming and channel module to process the radio frequency signal, and finally form a multi-target radio frequency signal after multi-channel digital beamforming.

[0063] For the phased array system, this embodiment adopts the adaptive digital beamforming technology. According to the weighting coefficients of the phased array antenna feeder network of the measured secondary radar system, calculate the phase weighting of each channel under different simulated azimuths and store it in the simulation system in the form of data.

[0064] For the verification of multi-target processing capabilities, this embodiment adopts the multi-target timing control technology. Based on the conventional secondary radar "interrogation-response" process, after real-time solving the current interrogation signal, form a multi-target timing sequence with the start time of the response coding as the reference point, including the distance delay, response azimuth simulation, phase shifter switching time, and response coding of each target. All target simulations are completed within the same interrogation period.

[0065] The maximum operating range R of the phased array secondary radar system in step 1 of this embodiment max Varies according to the different radar platforms used. The delay of the target simulation system includes the encoding / decoding processing delay tp, the phase shifter switching delay t s And the response coding duration t c . And the maximum operating range R max And the maximum distance delay t max (The maximum distance delay refers to the total time used in the transmission and return processes when the electromagnetic wave propagates at the maximum operating range) satisfies the relationship: t max = 2R max / c, where c is the speed of light. The maximum number of simulated targets Num max Then satisfies: Num max = t max / (t p + t s + t c) At this time, the minimum distance R between the simulated targets min Satisfies: R min =(t p +t s +t c )c / 2. During use, the target simulation system provides typical multi-target allocation use cases. When the target allocation use case is manually changed, the system performs a rationality check according to the above rules and prompts to avoid conflicts. In this embodiment, the maximum number of simulated targets can be calculated based on the minimum distance interval and the maximum operating distance of the secondary radar system under test, and is used for the operation display of the human-machine interface.

[0066] Step 2 of this embodiment specifically includes the following sub-steps:

[0067] Step 21: According to parameters such as the number of channels, antenna element spacing, and operating frequency of the phased array antenna feeder system (the antenna feeder system is the antenna feeder network system) of the secondary radar system under test, calculate the theoretical phase weighting value array of each channel at different azimuths relative to the normal of the phased array antenna surface of the secondary radar system under test: SIM_P i =f(x), where i is the antenna channel number, x∈(-BW / 2, BW / 2), and BW is the antenna beam width.

[0068] Step 22: Obtain the actual antenna pattern of the phased array secondary radar system. According to the wave position division of the phased array secondary radar, obtain the measured phase weighting value array of each channel forming the beam of each wave position: ∪ b (SSR_P i ), where b is the wave position number.

[0069] Step 23: Superimpose the measured phase weighting value array of each obtained channel with its corresponding theoretical phase weighting value array, then the phase weighting value array corresponding to the simulated target generated at each azimuth within the coverage range of each beam can be obtained: ∪ b (SSR_P i +SIM_P i ).

[0070] Step 24: According to the simulated target azimuth, combined with the phase weighting value array corresponding to the simulated target generated at each azimuth, allocate the corresponding beamforming phase shift control code for the simulated targets at different azimuths.

[0071] In this embodiment, by receiving the beam pointing azimuth of the secondary radar system online in real time, it is judged whether the current simulated target is within the antenna beam to determine whether the target simulation system generates a response signal.

[0072] Step 3 of this embodiment specifically includes the following sub-steps:

[0073] Step 31: Perform intermediate frequency sampling and decoding on the secondary radar interrogation signal received by the receiving module to form a decoding success trigger signal, triggering the generation of reply encoding.

[0074] Step 32: Taking the moment when the reply encoding is generated as the reference point, according to the target distance, start encoding from the nearest target (the so-called nearest target is the one with the smallest simulated distance value among all simulated targets, that is, the target closest to the secondary radar interrogation direction): First, encode each phase shifter in the beamforming and channel module according to the phase shift control code, and then perform reply distance counting (actual distance delay minus the time difference between the current moment and the starting point). After the counting is completed, generate reply data encoding (encode according to the target data in a preset format). Use this encoding process to encode other targets in sequence according to the target distance. Among them, the starting point of the reply distance counting for the next target is the time occupied by the simulation of all previous targets.

[0075] Step 4 of this embodiment is specifically as follows: Control the beamforming and channel module to first perform power splitting on the RF signal generated by the transmitting module to multiple RF channels, and then perform phase shifting respectively, and finally form a multi-target RF signal for receiving and processing by the phased array secondary radar system.

[0076] Embodiment 2

[0077] This embodiment proposes a multi-target simulation device for a phased array secondary radar system, as Figure 2 shown, including a first calculation unit, a second calculation unit, a timing generation unit, and a control unit.

[0078] Among them, the first calculation unit calculates the maximum number of simulated targets and the minimum distance between simulated targets according to the maximum operating distance of the phased array secondary radar system and the target simulation system delay.

[0079] The second calculation unit calculates the phase weighting value corresponding to the simulated target generated at each azimuth within the coverage range in real time according to the phased array secondary radar system towing azimuth and beam coverage range.

[0080] The timing generation unit forms a multi-target control timing with the starting moment of the reply encoding as the reference point according to the interrogation decoding information.

[0081] The control unit controls the transmitting module to generate an RF signal according to the multi-target control timing within the reply period, and controls the beamforming and channel module to process the RF signal, and finally forms multiple target signals after multi-channel digital beamforming.

[0082] Embodiment 3

[0083] This embodiment proposes a multi-target simulation system for a phased array secondary radar system, as Figure 3As shown, the system includes a signal processing module, a transmitting module, a receiving module, and a beamforming and channel module.

[0084] Among them, the transmitting module, the receiving module, and the beamforming and channel module are all communicatively connected to the signal processing module. The signal processing module serves as the main controller of the system and is used to control the transmitting module, the receiving module, and the beamforming and channel module.

[0085] The transmitting module is communicatively connected to the beamforming and channel module.

[0086] The signal processing module uses the multi-target simulation device proposed in the above Embodiment 2 to generate multi-target control serial numbers, and controls the beamforming and channel module to process the radio frequency signals generated by the transmitting module according to the multi-target control timing, so as to form multi-target radio frequency signals that can be used for the receiving and processing of phased array secondary radar systems.

[0087] The system of this embodiment further includes a power supply module, a main control computer, and a display.

[0088] Among them, the power supply module is used to supply power to the beamforming and channel module and the signal processing module; the signal processing module is communicatively connected to the main control computer, and is used to receive relevant data and control signals sent by the main control computer, and upload the processing results to the main control computer.

[0089] The main control computer is communicatively connected to the display.

[0090] The above specific implementation manners further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific implementation manners of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-target simulation method for a phased array secondary radar system, characterized in that Including: Calculating the maximum number of simulated targets and the minimum distance between simulated targets according to the maximum operating distance of the phased array secondary radar system and the delay of the target simulation system; Calculating in real time the phase weighting values corresponding to the simulated targets generated at each azimuth within the coverage range according to the towing azimuth of the phased array secondary radar system and the beam coverage range; Forming a multi-target control timing sequence with the starting moment of the response coding as the reference point according to the interrogation decoding information; Within the response period, controlling the transmitting module to generate radio frequency signals according to the multi-target control timing sequence, and controlling the beamforming and channel module to process the radio frequency signals to form multi-target radio frequency signals after multi-channel digital beamforming; The specific process of calculating in real time the phase weighting values corresponding to the simulated targets generated at each azimuth within the coverage range includes: Calculating the theoretical phase weighting value array of each channel at different azimuths relative to the normal of the antenna array surface according to the parameters of the phased array antenna feed system of the secondary radar system to be measured; Obtaining the actual antenna pattern of the phased array secondary radar system, and obtaining the measured phase weighting value array of each channel of each waveform-forming beam according to the wave position division of the phased array secondary radar; Superimposing the obtained measured phase weighting value array of each channel with its corresponding theoretical phase weighting value array, then the phase weighting value array corresponding to the simulated targets generated at each azimuth within the coverage range of each beam can be obtained; According to the azimuth of the simulated target, combining with the phase weighting value array corresponding to the simulated targets generated at each azimuth, allocating corresponding beamforming phase shift control codes for the simulated targets at different azimuths; The specific process of forming a multi-target control timing sequence with the starting moment of the response coding as the reference point according to the interrogation decoding information includes: Processing the secondary radar interrogation signal received by the receiving module to form a decoding success trigger signal, and triggering the generation of response coding; Taking the moment when the response coding is generated as the reference point, and starting coding from the target with the closest distance according to the target distance; the specific process of this coding includes: Encoding each phase shifter in the beamforming and channel module according to the phase shift control code; Performing response distance counting, and generating response data coding after the counting is completed; Using the above coding process to encode other targets in sequence according to the target distance, where the starting point of the response distance counting for the next target is the time occupied by the simulation of all previous targets.

2. The multi-target simulation method for a phased array secondary radar system according to claim 1, wherein The maximum detection range R of the phased array secondary radar system max varies according to the different radar platforms used; The target simulation system delay includes the codec processing delay t p , the phase shift switch delay t s and the response coding duration t c .

3. A multi-target simulation method for a phased array secondary radar system according to claim 2, characterized in that, The maximum operating range R max and the maximum distance time delay t max are related as follows: t max = 2R max / c, where c is the speed of light; Maximum number of simulation targets Num max Then it satisfies: Num max = t max / (t p + t s + t c ); At this time, the minimum distance R between the simulation targets min Then it satisfies: R min =(t p +t s +t c )c / 2.

4. A multi-target simulation method for a phased array secondary radar system according to claim 1, characterized in that, Before the step of forming a multi-target control timing sequence with the starting moment of the response coding as the reference point according to the interrogation decoding information, it also includes: Judging whether the current simulated target is within the antenna beam received in real time by receiving the beam pointing azimuth of the secondary radar system in real time, so as to determine whether the target simulation system generates a response signal.

5. A multi-target simulation method for a phased array secondary radar system according to claim 1, characterized in that, The specific process of controlling the beamforming and channel module to process the radio frequency signals is: First, performing power division processing on the radio frequency signals generated by the transmitting module to multiple radio frequency channels; Then, performing phase shift respectively, and finally forming multi-target radio frequency signals that can be used for the receiving and processing of the phased array secondary radar system.

6. A multi-target simulation device for a phased array secondary radar system, characterized in that, Including a first calculation unit, a second calculation unit, a timing generation unit and a control unit; The first calculation unit calculates the maximum number of simulated targets and the minimum distance between simulated targets according to the maximum operating range of the phased array secondary radar system and the delay of the target simulation system; The second calculation unit calculates, in real time, the phase weighting values corresponding to the simulated targets generated at each azimuth within the coverage range according to the tow azimuth of the phased array secondary radar system and the beam coverage range; The timing generation unit forms a multi-target control timing based on the interrogation decoding information, with the starting moment of the response coding as the reference point; During the response period, the control unit controls the transmitting module to generate radio frequency signals according to the multi-target control timing, and controls the beamforming and channel module to process the radio frequency signals, and finally forms multiple target signals after multi-channel digital beamforming; The real-time calculation of the phase weighting values corresponding to the simulated targets generated at each azimuth within the coverage range specifically includes: According to the parameters of the phased array antenna-feed system of the secondary radar system under test, calculating the theoretical value array of the phase weighting of each channel at different azimuths relative to the normal of the antenna array surface; Obtaining the actual antenna pattern of the phased array secondary radar system, and according to the wave position division of the phased array secondary radar, obtaining the measured value array of the phase weighting of each channel of each waveform-forming beam; Superposing the obtained measured value array of the phase weighting of each channel with its corresponding theoretical value array of the phase weighting, then the phase weighting value array corresponding to the simulated targets generated at each azimuth within the coverage range of each beam can be obtained; According to the azimuth of the simulated target, combining with the phase weighting value array corresponding to the simulated targets generated at each azimuth, allocating corresponding beamforming phase shift control codes for the simulated targets at different azimuths; The forming of the multi-target control timing based on the interrogation decoding information with the starting moment of the response coding as the reference point specifically includes: Processing the secondary radar interrogation signal received by the receiving module to form a decoding success trigger signal, triggering the generation of response coding; Taking the moment when the response coding is generated as the reference point, and starting the coding from the target with the closest distance according to the target distance; this coding process specifically includes: Encoding each phase shifter in the beamforming and channel module according to the phase shift control code; Performing response distance counting, and generating response data coding after the counting is completed; Using the above coding process to encode other targets in sequence according to the target distance, where the starting point of the response distance counting for the next target is the time occupied by the simulation of all previous targets.

7. A multi-target simulation system for a phased array secondary radar system, characterized in that, It includes a signal processing module, a transmitting module, a receiving module, a beamforming and channel module; The transmitting module, the receiving module, and the beamforming and channel module are all communicatively connected to the signal processing module; The signal processing module serves as the main controller of the system, and is used to implement the control of the transmitting module, the receiving module, and the beamforming and channel module; The signal processing module generates multi-target control sequence numbers by using the multi-target simulation device as described in claim 6, and controls the beamforming and channel module to process the radio frequency signals generated by the transmitting module according to the multi-target control timing, forming multi-target radio frequency signals that can be used for the receiving and processing of the phased array secondary radar system.

8. A multi-target simulation system for a phased array secondary radar system according to claim 7, characterized in that, It also includes a power supply module, a main control computer, and a display; The power supply module supplies power to each module in the system; The main control computer sends relevant data and control signals to the signal processing module and receives the processing results uploaded by the signal processing module; The display is communicatively connected to the main control computer.

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