External radiation source passive radar

Abstract

The invention provides an external radiation source passive radar, and belongs to the technical field of radars. Comprising a satellite reference signal acquisition antenna, a target echo acquisition antenna array, a satellite time service system, a satellite positioning system, a reference signal receiver, a target echo signal receiver, a cancellation processing module, an intermediate frequency processing module, a time service processing module, a data processing platform, an encryption VPN communication module, a communication adapter, a comprehensive data processing module and an ADS / AIS processing module. The invention aims to provide the passive radar with the external radiation source, so that high-precision target detection and positioning are realized, the concealment, the anti-interference capability and the maneuverability of the system are improved, an efficient regional air situation management and control system is provided, and the accuracy and the reliability of the system are improved at the same time.

Description

Technical Field

[0001] The present invention provides an external radiation source passive radar, belonging to the technical field of radar. Background Art

[0002] As an important detection device, the performance and function of radar are facing severe challenges. When a traditional active radar is working, it needs to emit powerful electromagnetic waves by itself, which is not only easy to be detected by the enemy's electronic reconnaissance equipment, thus exposing its own position, but also extremely vulnerable to the enemy's electronic interference in a complex electromagnetic environment, resulting in a decline or even failure of the detection performance. At the same time, there are also many limitations in aspects such as the transmission power and spectrum resources of the active radar, making it difficult to meet the growing diverse detection requirements.

[0003] The passive radar came into being. It cleverly uses the signals emitted by existing external radiation sources, such as television stations, FM radio stations, wireless mobile communication base stations, medium-orbit high-power network communication satellites, etc. to detect targets, without the need to emit signals by itself. This characteristic endows the passive radar with good concealment, greatly reducing the risk of being discovered by the enemy, and has extremely high application value in the military field.

[0004] However, there are still many problems exposed by the passive radars on the market in actual applications. For example, in terms of signal processing, it is difficult to effectively process complex multipath signals, resulting in low target positioning accuracy; the system integration degree is relatively low, the equipment volume is large, which is not conducive to rapid deployment and flexible application in different environments; there are deficiencies in the fusion and processing of multi-source signals, and it is impossible to make full use of the advantages of various external radiation source signals to build a comprehensive and efficient detection network. Therefore, it is of great practical significance to develop an external radiation source passive radar that can overcome the above defects, achieve high-precision target detection, have good mobility and concealment, and at the same time can build a perfect air defense early warning system.

[0005] Therefore, in view of this, research and improvement are carried out on the existing structure, and an external radiation source passive radar is proposed to solve the above existing problems. Summary of the Invention

[0006] The object of the present invention is to provide an external radiation source passive radar, which realizes high-precision target detection and positioning, improves the concealment, anti-interference ability and mobility of the system, provides an efficient regional air situation control system, and at the same time improves the accuracy and reliability of the system.

[0007] To solve the above problems, the technical solution proposed by the present invention is: an external radiation source passive radar, including a satellite reference signal acquisition antenna, a target echo acquisition antenna array, a satellite timing system, a satellite positioning system, a reference signal receiver, a target echo signal receiver, a cancellation processing module, an intermediate frequency processing module, a timing processing module, a data processing platform, an encrypted VPN communication module, a communication adapter, an integrated data processing module, and an ADS / AIS processing module.

[0008] The satellite reference signal acquisition antenna is used to receive the signals emitted by satellites and provide the original signal source for the system;

[0009] The target echo acquisition antenna array is used to acquire the satellite signals reflected by the aircraft in the relevant airspace, improving the sensitivity and directivity of signal reception;

[0010] The satellite timing system is used for receiver time matching and providing a reference time for networking to ensure the time synchronization of each part of the equipment;

[0011] The satellite positioning system provides the precise position of the site and matches the relevant electronic map;

[0012] The reference signal receiver receives the satellite direct transmission signal and determines the signal reference mode;

[0013] The cancellation processing module compares the acquired echo signal with the reference signal, eliminates the satellite directivity received by the target echo antenna, and extracts the effective echo signal;

[0014] The intermediate frequency processing module amplifies and complex demodulates the preprocessed signal of the receiver, obtains the path information of the echo signal, and reduces the overall volume of the system;

[0015] The encrypted VPN communication module encrypts and transmits the relevant data, and then transmits it to the terminal processing unit for comprehensive display, forming a networked air situation monitoring and warning system.

[0016] Further, the target echo signal receiver processes the received target reflection signal, determines the signal validity by comparing the reference signal with the echo signal, and obtains the effective echo signal and the target approximate information through Doppler frequency shift, different time reference determination, and signal strength threshold screening.

[0017] Further, the code rate ratio of the passive radar data code in the satellite timing system is less than 50B / S. Each data frame contains 20 C / A codes. Calculated according to four sampling points, the system sampling rate is 4.092MHz.

[0018] Further, the target echo signal receiver can easily capture the required carrier signal by capturing the C / A code, thereby measuring the time delay of satellite signal propagation. The C / A code element is 1023 bits, so the search for the C / A code can be quickly completed, and the echo information of the target can be obtained.

[0019] Further, the data processing platform combines the echo signal path information processed in the intermediate frequency with the electronic map to display the trajectory information, altitude information, and time information of the aerial target.

[0020] Further, the matching filter and FFT correlation algorithms of the intermediate frequency processing module both need to obtain the correlation values of the satellite signal and the local signal and apply them to the receiver, and select the type according to the capture speed and circuit complexity.

[0021] Further, the timing processing module receives the time reference and second pulse in the Beidou navigation timing satellite signal as the time reference of the signal source, provides the timing basis for the phase shift processing of each split receiver, and at the same time is used as the time comparison for the receiver to estimate the delay information.

[0022] Further, the communication adapter adapts and processes the delay information collected by the echo signal receiver through the wired and wireless communication transmission networks.

[0023] Further, the target motion trajectory coordinate information obtained by the integrated data processing module is combined with the electronic map to form a visual operation interface.

[0024] Further, the ADS / AIS processing module marks and processes the targets that conform to the ADS / AIS information displayed on the electronic map, reduces the alert level for normal flight information, raises the warning level for targets without ADS / AIS information, and transmits the relevant information to the big data processing platform. The big data processing platform comprehensively processes the data of various radar, multi-spectral optoelectronic, radio detection and other systems, conducts hierarchical and regional early warnings, connects to the national air situation system, constructs a regional air situation control system, controls medium and low-altitude flights, forms a low-altitude flight control network, and provides low-altitude economic control means.

[0025] Due to the adoption of the above technical solutions, the beneficial effects of an external radiation source passive radar of the present invention are as follows:

[0026] 1. Through the comprehensive utilization of multi-source signals and advanced signal processing technologies, including accurate Doppler frequency shift analysis, time shift decomposition processing, multi-path signal processing, etc., the present invention can accurately obtain information such as the motion trajectory and elevation of the target.

[0027] 2. Since the system itself does not need to emit signals, but uses the existing external radiation source signals for target detection, the probability of being detected by the enemy is greatly reduced, and it has excellent concealment.

[0028] 3. While the intermediate frequency processing module of the present invention realizes the signal processing function, it effectively reduces the overall volume of the system through optimized design.

[0029] 4. The ADS / AIS processing module of the present invention is combined with the big data processing platform, and can comprehensively and accurately monitor and manage the air targets in the area. Through the classification processing and early warning of different types of targets, a perfect regional air situation control system is constructed, realizing the effective control of medium and low altitude flights and forming a low altitude flight control network.

[0030] 5. The target echo signal receiver provides an accurate time reference for signal processing and target positioning through capturing the C / A code and the cooperation of other systems, improving the accuracy and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0032] Figure 1 is the system schematic diagram of a passive radar with an external radiation source of the present invention.

[0033] Figure 2 is the system working principle of a passive radar with an external radiation source of the invention.

[0034] Figure 3 is the schematic diagram of the signal composition of a passive radar with an external radiation source of the invention.

[0035] Figure 4 is the schematic diagram of signal acquisition modeling of a passive radar with an external radiation source of the invention.

[0036] Figure 5 is the schematic diagram of the C / A code generation principle of a passive radar with an external radiation source of the invention.

[0037] Figure 6 is the C / A code ambiguity function diagram of a passive radar with an external radiation source of the invention.

[0038] Figure 7 is the Doppler simulation model diagram of a passive radar with an external radiation source of the invention.

[0039] Figure 8 is the detection simulation diagram of a passive radar with an external radiation source of the invention.

[0040] Figure 9Schematic diagram of FFT parallel acquisition for an external radiation source passive radar invention.

[0041] Figure 10 Schematic diagram of FLL data stream for an external radiation source passive radar invention.

[0042] Figure 11 Schematic diagram of digital filtering for an external radiation source passive radar invention.

[0043] Figure 12 Integrated display map of air situation on the electronic map of the data processing platform for an external radiation source passive radar invention. Specific implementation mode

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] The present invention provides an external radiation source passive radar, including a satellite reference signal acquisition antenna, a target echo acquisition antenna array, a satellite timing system, a satellite positioning system, a reference signal receiver, a target echo signal receiver, a cancellation processing module, an intermediate frequency processing module, a timing processing module, a data processing platform, an encrypted VPN communication module, a communication adapter, an integrated data processing module, and an ADS / AIS processing module.

[0046] The satellite reference signal acquisition antenna is used to receive the signals emitted by the satellite and provide the original signal source for the system;

[0047] The target echo acquisition antenna array is used to acquire the satellite signals reflected by the aircraft in the relevant airspace, improving the sensitivity and directivity of signal reception;

[0048] The satellite timing system is used for receiver time matching and providing a reference time for networking to ensure time synchronization of each part of the equipment;

[0049] The satellite positioning system provides the precise position for the site and matches the relevant electronic map;

[0050] The reference signal receiver receives the satellite direct transmission signal and determines the signal reference mode;

[0051] The cancellation processing module compares the acquired echo signal with the reference signal, eliminates the satellite directivity received by the target echo antenna, and extracts the effective echo signal;

[0052] The intermediate frequency processing module gains and complex demodulates the preprocessed signal of the receiver, obtains the path information of the echo signal, and reduces the overall volume of the system;

[0053] The encrypted VPN communication module encrypts and transmits relevant data, and then transmits it to the terminal processing unit for comprehensive display, forming a networked air situation monitoring and warning system.

[0054] Furthermore, the target echo signal receiver processes the received target reflection signal, determines the signal validity by comparing the reference signal with the echo signal, and obtains effective echo signals and target approximate information through Doppler frequency shift, different time reference determination, and signal strength threshold screening.

[0055] The code rate ratio of the passive radar data code in the satellite timing system is less than 50 B / S. Each data frame contains 20 C / A codes. Calculated according to four sampling points, the system sampling rate is 4.092 MHz.

[0056] The target echo signal receiver can easily capture the required carrier signal by capturing the C / A code, thereby measuring the time delay of satellite signal propagation. The C / A code element = 1023 bit. Thus, the search for the C / A code can be quickly completed, and the echo information of the target can be obtained.

[0057] The data processing platform combines the echo signal path information processed in the intermediate frequency with the electronic map to display the trajectory information, altitude information, and time information of the aerial target.

[0058] The matching filter and FFT related algorithms of the intermediate frequency processing module both need to obtain the correlation values of satellite signals and local signals and apply them to the receiver, and select the type according to the capture speed and circuit complexity.

[0059] The timing processing module receives the time reference and second pulse in the Beidou navigation timing satellite signal as the time reference of the signal source, provides the timing basis for the phase shift processing of each split receiver, and is used as the time comparison for the receiver to estimate the delay information.

[0060] The communication adapter adapts the delay information collected by the echo signal receiver through the wired and wireless communication transmission network.

[0061] The target motion trajectory coordinate information obtained by the comprehensive data processing module is combined with the electronic map to form a visual operation interface.

[0062] The ADS / AIS processing module annotates and processes the targets that conform to ADS / AIS information on the electronic map, reduces the alert level for normal flight information, raises the warning level for targets without ADS / AIS information, and transmits the relevant information to the big data processing platform. The big data processing platform comprehensively processes the data of various systems such as radars, multi-spectral optoelectronics, and radio detection, conducts hierarchical and zonal early warnings, connects to the national air situation system, constructs a regional air situation control system, controls medium and low-altitude flights, forms a low-altitude flight control network, and provides means for low-altitude economy control.

[0063] Based on the "CSAIA satellite 5G broadband" signal, this system solves the difficulties such as frequency division multiplexing, multi-satellite time shift, time shift signal acquisition of the target by the antenna array at multiple points, multi-satellite signal acquisition, and multi-satellite signal multipath processing, and solves the key points of forming the target trajectory and three-dimensional positioning by a single site through the array antenna to obtain the time shift signal, thus forming a new passive radar system with the "CSAIA satellite 5G broadband" Internet satellite signal as the main and signals such as radio and television, GSM, FDD, and LTE as the auxiliary. And through the advantages of Internet satellites, it forms an autonomous encrypted mobile communication system that does not rely on wired transmission networks, MESH self-organizing networks, etc., so as to realize a seamless and all-weather national air defense early warning network.

[0064] When the aircraft in the relevant airspace passes through the relevant surveillance airspace, the aircraft will reflect the radio signals radiated by the satellite and produce diffraction.

[0065] The passive radar system receives the signals directly transmitted by the satellite as a reference, and receives the signals reflected and diffracted by the target, and extracts effective information by comparison, eliminates the interference of the satellite direct signal entering the target receiving antenna and the mutual interference generated by multiple satellite signals with the reference signal, and obtains an effective target echo signal.

[0066] Multiple receivers respectively process the signals received by the relevant antennas and process them separately, perform Doppler frequency shift and time shift decomposition processing on the received signals, obtain the single time point information of the target, and enter the cancellation processing module and intermediate frequency processing module for processing.

[0067] The intermediate frequency processing module converges different single point information, performs signal gain and complex demodulation, separates them according to different time bases, obtains the path information of the echo signal, and obtains the time difference of the target signal according to different time bases, so as to form information such as the movement trajectory and elevation of the target.

[0068] The trajectory information processed by the intermediate frequency processing module is comprehensively processed by the data processing platform and combined with the electronic map, so as to form a visible air situation display for decision-making.

[0069] The reference signal receiver receives the direct satellite signal, obtains the signal feature code, discards the recognition of signals such as multi-satellite multipath, multi-satellite mutual interference, and single-satellite clutter, obtains effective signal information, and obtains signal modeling.

[0070] The medium-earth orbit Internet satellites are generally no less than 24. At any position, signals from no less than three satellites can be received simultaneously. The signals transmitted by the Internet satellites generally use the 5G LTE system, and its signal mathematical representation is:

[0071]

[0072] Among them, K is the satellite number, F L1 is the signal frequency, ψ 1 is the initial phase of the upper code, D K (T) is the transmitted signal, and Pc(T) is the C / A code power.

[0073] The D code (network data) is first formed into the L1 carrier wave by superimposing and modulating the pseudo-noise C / A code and the network data code. The C / A and the L2 carrier wave are in quadrature phase on the L1 carrier wave. Therefore, there will be a 90-degree phase shift between the combined frequencies of these two L1 carrier waves and the C / A plus the network data. The modulation of the L2 carrier wave is basically the same as that of the L1. Finally, the satellite transmits the modulated L1 / L2 network data to the ground, forming the uplink and downlink data streams of the Internet satellite, as Figure 3 shown.

[0074] In the application, the network data itself does not have an essential impact on the required illumination source. Therefore, we use the C / A code stream as the illumination source of the passive radar. The function of the reference signal receiver is to separate the C / A code stream and suppress the recognition of signals such as multi-satellite multipath, multi-satellite mutual interference, and single-satellite clutter, obtain effective signal information, and obtain signal modeling, as Figure 4 shown.

[0075] The C / A code of the target echo signal receiver is short and easy to capture. By capturing the C / A code, the required carrier signal can be easily captured, thereby measuring the time delay of the satellite signal propagation. The C / A code element = 1023 bit. Thus, the search for the C / A code can be quickly completed, and the echo information of the target can be obtained, as Figure 5 shown.

[0076] The resulting C / A code (1.023 MHz) has the following mathematical expression:

[0077]

[0078] In the formula, N is the C / A code length (N = 2 10 -1 = 1023 bit), T c is the code element width (T c = 1 / f1 = 0.977 μs, equivalent to 293.1 m), T r is the period (T r = NT c = 1 ms), k is the number of signal repetition periods (32). Since the C / A code needs to be modulated by BPSK, when analyzing the signal, the corresponding 0 and 1 values become 1 and -1.

[0079] In the passive radar system based on Internet satellite signals, the code rate ratio of the data code is less than 50 B / S. Each data frame contains 20 C / A codes. Calculated according to four sampling points, the system sampling rate is 4.092 MHz, and the simulation ambiguity function is as Figure 6 shown.

[0080] Since medium Earth orbit satellites are relatively far from the ground, generally located above an orbit of 3000 km, with a large coverage area, but relatively weak signals compared to radio and television station signals. According to the relative conditions of antenna gain and satellite orbit height, the key point of the passive radar system based on Internet satellite radiation sources is weak signal detection.

[0081] According to the current 1.5 GHz surrounding frequency used by CSAIA, the symbol duration is about 0.9 μs, the period is 1 ms, and each period has 1023 symbols. Then the ground power density is:

[0082] Among them, D1 is the ground power, P1 is the transmit power, G1 is the antenna gain, EIRP is the equivalent isotropic radiated power, R0 is the satellite orbit height, and LT is the transmission loss.

[0083] Then the received reference signal power is: P r1 = D 1 A r1 G proc

[0084] The receiver noise is: P N = KT 0 BF 0 , and the power density of the target echo reaching the receiving antenna:

[0085] From this simulation calculation, the ambiguity function after receiving the C / A code has a significant contrast and has good resolution in both range and Doppler amplitude values.

[0086] Therefore, the passive radar system using Internet satellite radiation sources has greater advantages compared to using GPS satellite signals and direct broadcast satellite TV signals.

[0087] The passive radar of the Internet satellite radiation source uses more than 10 receiving modules in parallel. By using conditions such as the frequency shift, time difference, and Doppler phase difference of the received signals, it can effectively solve the instantaneous positions of the target at different time points and display them after complex demodulation at the data processing terminal, realizing the display of a single-machine electronic map and making the display interface more intuitive.

[0088] The terminal signal receiving sensitivity of the Internet satellite for users is poor, and data is transmitted up and down simultaneously. Therefore, the power of the Internet satellite is generally larger than that of satellites such as GPS and live broadcast of radio and television, and the orbit is relatively lower, which is more conducive to long-distance detection.

[0089] The intermediate-frequency signal captured by the intermediate-frequency processing module is supposed to be: r(k) = Ad(k)c(k)cos[(ω0 + ω d )k] + n(k).

[0090] Among them, A is the signal amplitude, d(k) is the modulated symbol, c(k) is the pseudo-random code, ω 0 is the intermediate-frequency carrier angular frequency, ω d is the Doppler modulation angular frequency, and n(k) is the band-limited Gaussian white noise. The in-phase I and quadrature Q of the local carrier are cos[(ω 0 + w d )k + φ] and sin[(ω 0 + ω d )k + φ] respectively. After orthogonal digital down-conversion, low-pass filtering, and filtering by the integration cleaning filter, ignoring the influence of the noise term, the integration outputs of the I and Q channels are

[0091]

[0092] Among them, T c is the chip width, Δω = (ω′ 0 - ω 0 ) + (ω′ d - w d ) is the residual frequency difference, φ is the initial phase of the local carrier, and the local pseudo-code is r is the input time delay of the local code clock, L is the number of accumulated chips, that is, the correlation integration length. When complete correlation occurs, L is the number of chips within a pseudo-code period

[0093] When the received pseudo-code is completely aligned with the local pseudo-code, τ = 0, After square-law detection, the squared sample value after the k-th integration cleaning is

[0094]

[0095] Both the matched filter and the FFT correlation algorithm need to obtain the correlation values of the satellite signal and the local signal and apply them to the receiver, and select the type according to the capture speed and circuit complexity.

[0096] After the receiver intermediate frequency processing is restored, the FLL is combined with digital filtering. In the digital filtering, the noise bandwidth is significantly suppressed, reducing the error of noise on target acquisition and facilitating the improvement of positioning accuracy.

[0097] The intermediate frequency processing also reduces the burden of the backend comprehensive processing, making the whole system as small as possible. At the same time, it reduces the requirements for the data processing server, facilitating the concealed deployment, unattended operation, and uninterrupted work of the system. Compared with the previous active / passive radar primary processing methods, it has a significant improvement.

[0098] For the integrated data processing module, the receiver processes in parallel through multiple receiving modules, enabling the passive radar single unit to have the complete electronic map composite ability, and the single-station data can be transmitted to the backend for comprehensive processing to form a large-scale air situation display of the local / national area, providing a more intuitive and convenient interaction interface for decision-making.

[0099] The above describes the present invention and its implementation manners. This description is not restrictive. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention creation, design similar structural manners and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. An external radiation source passive radar, characterized in that: It includes satellite reference signal acquisition antenna, target echo acquisition antenna array, satellite timing system, satellite positioning system, reference signal receiver, target echo signal receiver, cancellation processing module, intermediate frequency processing module, timing processing module, data processing platform, encrypted VPN communication module, communication adapter, integrated data processing module and ADS / AIS processing module. The satellite reference signal acquisition antenna is used to receive signals transmitted by satellites and provide an original signal source for the system; The target echo acquisition antenna array is used to acquire satellite signals reflected by aircraft in the relevant airspace, thereby improving the sensitivity and directivity of signal reception; The satellite timing system is used for receiver time matching and provides reference time for networking, ensuring time synchronization of various devices; The satellite positioning system provides the precise location of the site and matches the relevant electronic map; The reference signal receiver receives a satellite direct transmission signal and determines a signal reference mode; The cancellation processing module compares the acquired echo signal with the reference signal, eliminates the directness of the satellite received by the target echo antenna, and extracts the effective echo signal; The intermediate frequency processing module increases the gain of the receiver preprocessing signal and performs multiplexing to obtain the path information of the echo signal, thereby reducing the total volume of the system; The encrypted VPN communication module encrypts and transmits relevant data, and then transmits it to the terminal processing unit for comprehensive display, forming a networked air situation monitoring and early warning system.

2. The external radiation source passive radar according to claim 1, characterized in that: The target echo signal receiver processes the received target reflection signal, determines the signal validity by comparing the reference signal with the echo signal, and obtains the effective echo signal and target general information through Doppler frequency shift, different time base determination, and signal strength threshold screening.

3. The external radiation source passive radar according to claim 1, characterized in that: The code rate ratio of the passive radar data code in the satellite timing system is less than 50B / S, each data frame contains 20 C / A codes, and calculated based on four sampling points, the system sampling rate is 4.092MHz.

4. The external radiation source passive radar according to claim 1, characterized in that: The target echo signal receiver can easily capture the required carrier signal by capturing the C / A code, thereby measuring the time delay of satellite signal propagation. The C / A code element = 1023 bits, thereby quickly completing the C / A code search and obtaining the target echo information.

5. The external radiation source passive radar according to claim 1, characterized in that: The data processing platform displays the trajectory information, altitude information and time information of the aerial target based on the echo signal path information processed by the intermediate frequency in combination with the electronic map.

6. The external radiation source passive radar according to claim 1, characterized in that: The intermediate frequency processing module matching filter and FFT correlation algorithm both need to obtain satellite signal and local signal correlation values, and are applied to the receiver, and are selected according to the capture speed and circuit complexity.

7. The external radiation source passive radar according to claim 1, characterized in that: The timing processing module receives the time reference and second pulse in the Beidou navigation timing satellite signal as the time reference of the signal source, provides a timing basis for the phase shift processing of each split receiver, and provides the receiver with a time comparison for estimating delay information.

8. The external radiation source passive radar according to claim 1, characterized in that: The communication adapter adapts and processes the time delay information collected by the echo signal receiver through the wireless communication transmission network.

9. The external radiation source passive radar according to claim 1, characterized in that: The target motion track coordinate information obtained by the comprehensive data processing module is combined with the electronic map to form a visual operation interface.

10. The external radiation source passive radar according to claim 1, characterized in that: The ADS / AIS processing module marks and processes targets that meet the ADS / AIS information displayed on the electronic map, lowers the alert level for normal flight information, increases the warning level for targets without ADS / AIS information, and transmits relevant information to the big data processing platform. The big data processing platform comprehensively processes the data of various radar, multi-spectral optoelectronic, radio detection and other systems, conducts graded and regional warnings, connects to the national defense air situation system, builds a regional air situation control system, controls medium and low altitude flights, forms a low altitude flight control network, and provides low altitude economic control means.

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