A full-band satellite ground station electromagnetic environment monitoring system

Abstract

The present invention relates to the field of electromagnetic environment monitoring of satellite ground stations, and specifically to a full-band electromagnetic environment monitoring system for satellite ground stations. The system comprises a monitoring and direction-finding subsystem and an information processing subsystem. The omnidirectional real-time monitoring device and the directional high-sensitivity monitoring device receive interference signals via corresponding monitoring antennas and direction-finding antennas, and transmit the received interference signals to corresponding radio frequency receivers. The radio frequency receiver antenna processes the received signals and outputs intermediate frequency signals, which are then transmitted to corresponding signal processing units. The signal processing units sample the input signals and perform down-conversion, filtering, and extraction preprocessing operations according to a specified frequency. The preprocessed data are analyzed and direction-finding is monitored. The monitoring direction-finding data is transmitted to the information processing subsystem. The information processing subsystem receives the ground station monitoring results and performs fusion statistical processing. The present invention is suitable for electromagnetic environment monitoring of satellite ground stations.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic environment monitoring of satellite ground stations, and in particular to a full-band electromagnetic environment monitoring system for satellite ground stations. Background Art

[0002] Satellite communications are an indispensable infrastructure in the modern information society and are widely used in broadcasting and television, emergency communications, distance education, military command, the Internet of Things, aviation and navigation, and other fields.

[0003] As a key node in the satellite system, the satellite ground station (earth station) is responsible for uplink (transmission) and downlink (reception) communications with the satellite. Its performance is directly related to the reliability and quality of the entire satellite link.

[0004] However, satellite communication links, particularly downlink receive links, are extremely susceptible to electromagnetic interference. Interference can lead to degraded communication quality (increased bit error rates, signal interruptions), data loss, or even complete paralysis, resulting in significant economic losses and security risks. Traditional monitoring methods, however, suffer from significant deficiencies in coverage (frequency / spatial), real-time performance, continuity, automation, data processing depth, and situational awareness. These methods are unable to effectively meet the requirements for comprehensive, real-time, accurate, and intelligent monitoring of the ground station's electromagnetic environment, and thus struggle to provide timely and reliable decision-making for proactive interference prevention and optimized spectrum management.

[0005] Therefore, the development of an advanced, full-band electromagnetic environment monitoring system for satellite ground stations has become an inevitable technological development trend. This system requires the integration of cutting-edge technologies such as broadband reception, high-speed processing, distributed networking, big data analysis, and artificial intelligence to achieve all-weather, full-band, high-precision, and intelligent monitoring of the electromagnetic environment surrounding ground stations, providing solid technical support for ensuring the secure, reliable, and efficient operation of satellite communications. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a full-band satellite ground station electromagnetic environment monitoring system, which realizes all-weather, full-band, high-precision and intelligent monitoring of the electromagnetic environment around the ground station.

[0007] The present invention adopts the following technical solutions to achieve the above-mentioned purpose. The present invention provides a full-band satellite ground station electromagnetic environment monitoring system, comprising:

[0008] Monitoring and direction-finding subsystem and information processing subsystem. The full-band satellite ground station electromagnetic environment monitoring system is deployed in the StarNet information gateway station. The monitoring and direction-finding subsystem includes omnidirectional real-time monitoring equipment and directional high-sensitivity monitoring equipment. The omnidirectional real-time monitoring equipment and directional high-sensitivity monitoring equipment are installed outdoors through fixed brackets and connected to indoor equipment.

[0009] The omnidirectional real-time monitoring equipment and the directional high-sensitivity monitoring equipment receive interference signals through the corresponding monitoring antennas and direction-finding antennas, and send the received interference signals to the corresponding RF receivers. The RF receiver antennas filter, amplify, and frequency-convert the received signals, then output intermediate frequency signals and send them to the corresponding signal processing units.

[0010] The corresponding signal processing unit samples the input signal and performs down-conversion, filtering, and extraction pre-processing operations according to the specified frequency, and completes the FFT and signal search and detection functions. It analyzes and monitors the direction-finding of the pre-processed data, and transmits the monitoring direction-finding data to the information processing subsystem;

[0011] The information processing subsystem receives the monitoring results from the ground station and performs integrated statistical processing, including monitoring results, direction finding azimuth, and equipment status information, and finally completes the display of working parameters, data statistics, and equipment status.

[0012] Furthermore, the omnidirectional real-time monitoring device receives instructions from the display and control computer of the information processing subsystem, performs signal monitoring tasks and target signal lateral tasks, and when performing the signal monitoring task, selects the monitoring antenna according to the system settings, and sends the electromagnetic wave signal received by the monitoring antenna to the broadband radio frequency receiver of the omnidirectional real-time monitoring device. The broadband radio frequency receiver down-converts the electromagnetic wave signal into an intermediate frequency signal, and the signal processing unit of the omnidirectional real-time monitoring device completes the digital processing of the intermediate frequency signal, and sends the processing result to the display and control computer for display and processing, completing the measurement of the signal frequency, level, and bandwidth, as well as the intermediate frequency spectrum analysis and scanning functions.

[0013] Furthermore, when performing the target signal direction-finding task, the narrowband RF receiver of the omnidirectional real-time monitoring equipment is controlled to tune to the specified frequency point, and the 1-3GHz, 3-8GHz, and 8-21.5GHz direction-finding antennas are selected. The RF switching switch of the omnidirectional real-time monitoring equipment is used for switching, and the signals of each antenna element are sent to the 1-3GHz, 3-8GHz, and 8-21.5GHz dual-channel RF receivers in sequence. The signals are down-converted to intermediate frequency signals. The signal processing unit of the omnidirectional real-time monitoring equipment performs A / D acquisition on the intermediate frequency signals, and then performs DDC (Digital Down-Conversion Filtering) filtering and FFT (Fast Fourier Transform) digital processing. Finally, direction-finding calculations are performed to obtain the incident direction of the signal.

[0014] Furthermore, the directional high-sensitivity monitoring equipment adopts an integrated design. The monitoring direction-finding antenna, L / S, C, Ka, Q / V radio frequency receivers, and signal processing unit of the directional high-sensitivity monitoring equipment are integrated in its own antenna cover. The directional high-sensitivity monitoring equipment receives instructions from the display and control computer and performs the task of investigating and handling interference signals.

[0015] When performing the task of investigating and handling interference signals, the monitoring and direction-finding antenna of the corresponding frequency band is selected according to the system settings, and each monitoring and direction-finding antenna of the frequency band is switched one by one through the RF switching switch of the directional high-sensitivity monitoring equipment. A set time is set for each monitoring and direction-finding antenna to search for the signal. The monitoring and direction-finding antenna sends the received electromagnetic wave signal to the L / S, C, Ka, Q / V RF receiver, down-converts it into an intermediate frequency signal, and the signal processing unit of the directional high-sensitivity monitoring equipment completes the digital processing of the intermediate frequency signal, and sends the processing result to the monitoring and direction-finding software of the directional high-sensitivity monitoring equipment for processing, so as to realize spectrum scanning to find interference signals, identify interference signals, store the processed data and send relevant results to the display and control computer.

[0016] Furthermore, directional, high-sensitivity monitoring equipment uses phased array antenna beam scanning to achieve spatial coverage. Four spectrum segments are scanned in parallel, with each segment divided into spectrum scanning and narrowband control and monitoring. Spectrum scanning is used for coarse detection of full-bandwidth signals. The center frequency and bandwidth of the signal are calculated based on the threshold and spectrum. Multiple scans are performed on a single surface, and the maximum value of the spectrum obtained from multiple scans is taken as the spectrum signal of that surface. Other surfaces are then scanned in sequence to obtain four sets of spectrum signals. These four sets of spectrum signals are uploaded to the display and control computer, which uses the maximum value of the four sets of spectrum as the final spectrum data. During the initial control through narrowband control and monitoring, a 360-degree omnidirectional scan is performed. The signal processing unit selects the IQ group with the highest power for modulation identification, parameter measurement, and direction finding. Subsequent continuous control and monitoring of the signal uses the previous beam for direct monitoring. IQ refers to the in-phase component (I) and quadrature component (Q) of the signal.

[0017] The beneficial effects of the present invention are:

[0018] The present invention can achieve full frequency band coverage, supporting UHF / VHF, S, C, Ku, Ka, Q / V and other frequency bands, covering the mainstream satellite communication frequency bands (such as L-band 1-2 GHz, Ka-band 26.5-40 GHz), and can be expanded to millimeter wave (30-300 GHz) and optical communication frequency bands (such as laser communication).

[0019] The present invention can realize real-time spectrum monitoring, and implement spectrum scanning, signal power detection, and modulation identification through a broadband receiver (such as software-defined radio, SDR), and trigger an alarm when an abnormal signal (such as illegal interference, co-channel interference, and adjacent channel leakage) is detected.

[0020] The present invention can locate and suppress interference sources. It uses TDOA (time difference of arrival) or AOA (angle of arrival) technology, combined with multi-station collaboration to achieve geographical positioning of interference sources (with an accuracy of up to 100 meters), and generate suppression strategies (such as beamforming and frequency avoidance) in real time.

[0021] The present invention can realize data management and analysis, establish an electromagnetic environment database, support historical data backtracking, spectrum occupancy statistics, interference event correlation analysis, and machine learning algorithms: identify typical interference patterns (such as pulse interference, continuous wave interference, and swept frequency interference).

[0022] The present invention complies with the International Telecommunication Union (ITU) and national radio management regulations and generates monitoring reports (such as spectrum occupancy and field strength distribution). BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural block diagram of a full-band satellite ground station electromagnetic environment monitoring system provided by the present invention;

[0024] Figure 2 This is a schematic diagram of the connection between the outdoor equipment and the indoor equipment provided by the present invention;

[0025] Figure 3 This is a block diagram of the monitoring principle of the omnidirectional real-time monitoring device provided by the present invention;

[0026] Figure 4 This is a structural diagram of the omnidirectional real-time monitoring device provided by the present invention;

[0027] Figure 5 This is a flowchart of the interference signal search process provided by the present invention;

[0028] Figure 6 This is the phased array spectrum monitoring and control process provided by the present invention;

[0029] Figure 7 This is a schematic diagram of the interface relationship provided by the present invention. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0031] The present invention provides a full-band satellite ground station electromagnetic environment monitoring system, such as Figure 1As shown, it includes: monitoring and direction-finding subsystem, information processing subsystem and supporting facilities.

[0032] The monitoring and direction-finding subsystem includes omnidirectional real-time monitoring equipment and directional high-sensitivity monitoring equipment. The omnidirectional real-time monitoring equipment includes the corresponding monitoring antenna, lateral antenna, RF switch, narrowband RF receiver, signal processing unit, positioning module, and power module. The directional high-sensitivity monitoring equipment includes the corresponding lateral monitoring antenna, RF switch, L / S, C, Ka, Q / V RF receivers, and signal processing unit.

[0033] The information processing subsystem includes server switches, display and control computers, and monitoring software.

[0034] Supporting facilities include installation accessories, generators and portable monitoring equipment.

[0035] The monitoring system provided by this invention is deployed at a StarNet gateway station, relying on a central interconnection architecture to achieve multi-site information exchange. It has the ability to continuously monitor the full-band electromagnetic environment in the area surrounding the gateway station without human intervention. Its core functions include:

[0036] Global perception of interference signals: Real-time scanning through broadband receiving equipment to discover and capture potential interference signals;

[0037] Intelligent threat identification: Automatically identifies interference types (co-frequency / adjacent frequency / malicious blocking, etc.) based on the signal signature library;

[0038] High-precision directional positioning: Phased array direction finding technology is used to achieve millimeter-level azimuth tracking of interference sources (accuracy ≤±1°);

[0039] All-time operation guarantee: supporting facilities provide 24-hour uninterrupted power supply, environmental adaptation and data transmission support.

[0040] Specifically, the core functions of the system are as follows:

[0041] 1. Full frequency band coverage

[0042] Supports UHF / VHF, S, C, Ku, Ka, Q / V and other frequency bands, covering mainstream satellite communication frequency bands (such as L-band 1-2GHz, Ka-band 26.5-40GHz).

[0043] It can be extended to millimeter wave (30-300 GHz) and optical communication bands (such as laser communication).

[0044] 2. Real-time spectrum monitoring

[0045] Spectrum scanning, signal power detection, and modulation identification are achieved through a wideband receiver (such as software-defined radio, SDR).

[0046] Dynamic threshold alarm: Triggers an alarm when an abnormal signal (such as illegal interference, co-channel interference, and adjacent channel leakage) is detected.

[0047] 3. Interference source location and suppression

[0048] Using TDOA (Time Difference of Arrival) or AOA (Angle of Arrival) technology, combined with multi-station collaboration, the interference source can be geographically located (with an accuracy of up to 100 meters).

[0049] Adaptive filtering technology: Generates suppression strategies (such as beamforming and frequency avoidance) in real time.

[0050] 4. Data Management and Analysis

[0051] Establish an electromagnetic environment database to support historical data backtracking, spectrum occupancy statistics, and interference event correlation analysis.

[0052] Machine learning algorithms: Identify typical interference patterns (such as pulse interference, continuous wave interference, and swept frequency interference).

[0053] 5. Compliance Verification

[0054] Comply with the International Telecommunication Union (ITU) and national radio management regulations and generate monitoring reports (such as spectrum occupancy and field strength distribution).

[0055] The system architecture of the present invention is as follows:

[0056] 1. Hardware layer

[0057] Antenna arrays: wideband log-periodic antennas, parabolic directional antennas, and multi-beam phased array antennas.

[0058] RF front end: low noise amplifier, downconverter, high-speed ADC (Analog-to-Digital Converter) and DAC (Digital-to-Analog Converter).

[0059] Signal processing unit: a real-time signal processing module accelerated by FPGA (Field-Programmable Gate Array) and GPU (Graphics Processing Unit).

[0060] 2. Software layer

[0061] Spectrum analysis software (such as GNU Radio, Spectrum Analyzer Pro).

[0062] Geographic Information System: Visually display the location of interference sources and signal propagation models.

[0063] Automation control platform: supports remote control and task scheduling (such as scheduled scanning and monitoring of key frequency bands).

[0064] 3. Network layer

[0065] Distributed deployment: multi-node data synchronization (5G backhaul or satellite link).

[0066] Cloud platform integration: Data is uploaded to the cloud for big data analysis and AI model training.

[0067] The key technologies of the present invention are as follows:

[0068] 1. Balance between wide bandwidth and high sensitivity

[0069] Full-band coverage requires solving the broadband matching problem between antennas and RF links to avoid signal distortion.

[0070] High-sensitivity receivers are easily affected by noise and require the use of cryogenic cooling technology or digital noise reduction algorithms.

[0071] 2. Real-time performance and computing resources

[0072] High-speed sampling generates massive amounts of data. High-speed sampling GSPS (Giga Samples Per Second)-level ADCs require edge computing to reduce the burden on the cloud, such as FPGA preprocessing.

[0073] 3. Adaptability to complex electromagnetic environments

[0074] Multipath effects and 5G base station stray signals in urban environments may affect monitoring accuracy, requiring multi-sensor data fusion.

[0075] This system surpasses the upper limits of traditional monitoring frequency bands, supporting UHF / VHF, S, C, Ku, Ka, Q / V bands, and covers mainstream satellite communication bands (such as L-band 1-2 GHz and Ka-band 26.5-40 GHz). It can also be expanded to millimeter wave (30-300 GHz) and optical communication bands (such as laser communications). This significantly improves the efficiency of high-frequency interference detection and control, establishing an automated electromagnetic protection barrier for satellite gateways.

[0076] The working process of each subsystem of the present invention is described in detail below.

[0077] In the monitoring and direction-finding subsystem, the monitoring antennas and direction-finding antennas of the omnidirectional real-time monitoring equipment and the directional high-sensitivity monitoring equipment receive the interference signals and send the received signals to the corresponding RF receivers;

[0078] The signal received by the RF receiver antenna is filtered, amplified, frequency-converted, and then output as an intermediate frequency signal, which is sent to the corresponding signal processing unit;

[0079] The signal processing unit samples the input signal and sends the sampled signal to the FPGA for pre-processing operations such as down-conversion, filtering, and extraction according to the specified frequency. It can also complete functions such as FFT and signal search and detection. The pre-processed data is further processed to realize signal analysis and direction finding. The monitoring and direction finding data can be transmitted to the information processing subsystem through the network.

[0080] The information processing subsystem receives the site monitoring results and performs fusion statistics and other processing, including monitoring results, direction finding azimuth, equipment status and other information, and completes the display of working parameters, data statistics and equipment status.

[0081] The omnidirectional real-time monitoring device and the directional high-sensitivity monitoring device of the present invention are described in detail below.

[0082] Omnidirectional real-time monitoring equipment and directional high-sensitivity monitoring equipment are installed outdoors through fixed brackets and connected to indoor equipment through optical fibers, optical terminals, network cables, switches, and power cables. The connection diagram is as follows: Figure 2 shown.

[0083] The omnidirectional real-time monitoring equipment receives the display and control computer instructions to realize the electromagnetic environment monitoring in the area near the designated gateway station, providing support for analyzing and evaluating the electromagnetic environment in its coverage area, discovering interference sources, quickly capturing interference signals, identifying interference types, etc., and providing an important basis for building the electromagnetic situation in its area. The monitoring principle block diagram of the omnidirectional real-time monitoring equipment is as follows: Figure 3 As shown, its structure is as Figure 4 shown.

[0084] The monitoring antenna includes 1-18GHz and 18-47GHz antennas, the direction-finding antenna array includes 1-3GHz, 3-8 GHz and 8-21.5GHz direction-finding antenna arrays, the RF receiver includes a broadband RF receiver and a narrowband RF receiver, and the corresponding signal processing unit includes a signal acquisition and processing module, an electronic compass, a Beidou module, a main control module, and a hard disk. The electronic compass and Beidou module are respectively connected to the signal acquisition and processing module, and the hard disk is connected to the main control module.

[0085] a) Signal monitoring

[0086] During monitoring, the monitoring antenna is selected according to the system settings, and the electromagnetic wave signals received by the monitoring antenna are transmitted to the broadband RF receiver. The broadband RF receiver down-converts the electromagnetic wave signals to an intermediate frequency (IF) signal. The signal processing unit digitally processes the IF signal and transmits the results to the display and control computer for display and processing. This system measures ITU parameters such as signal frequency, level, and bandwidth, and performs IF spectrum analysis and scanning. This system enables electromagnetic signal monitoring, interference signal detection and identification, parameter measurement, and occupancy statistics, providing dynamic electromagnetic environment perception data for interference signal monitoring and electromagnetic environment status display. To prevent damage to equipment caused by high-power uplink satellite transmissions, the system is equipped with a wave limiter, which can be configured according to site conditions.

[0087] b) Target signal direction finding

[0088] This project fully utilizes the direction-finding advantages of different systems according to different frequency bands to ensure the overall direction-finding performance of the equipment and adopts a dual-channel correlation interferometer direction-finding system.

[0089] The directional, highly sensitive monitoring equipment features an integrated design, with the monitoring direction-finding antenna, L / S, C, Ka, and Q / V radio frequency receivers, and signal processing unit integrated within the radome. When the directional, highly sensitive monitoring equipment receives instructions from the display and control computer to investigate and address satellite interference in a specific frequency band, it searches for the interfering signal, promptly identifying it and determining its direction.

[0090] a) Discovery of Interference Signals

[0091] When performing interference signal investigation and handling tasks, the monitoring and direction-finding antenna of the corresponding frequency band is selected according to the system settings, and each monitoring and direction-finding antenna of the frequency band is switched one by one through the RF switch. A certain period of time is spent at each monitoring and direction-finding antenna to search for the signal. The electromagnetic wave signal received by the monitoring and direction-finding antenna is sent to the L / S, C, Ka, Q / V RF receiver, down-converted into an intermediate frequency signal, and the intermediate frequency signal is digitally processed by the signal processing unit, and the processing result is sent to the monitoring and direction-finding software for display and processing, so as to realize spectrum scanning to find interference signals, identify interference signals, store the processed data and send the relevant results to the display and control computer, such as Figure 5 shown.

[0092] The antennas for the four frequency bands are arranged on the four slopes of a pyramid, with a 35° inclination angle. The antennas radiate perpendicular to the slopes, with fixed beams covering 0-70° in elevation and scanning beams covering ±45° in azimuth. The pyramid is approximately 240mm tall.

[0093] Phased array spectrum monitoring is described below.

[0094] Directional monitoring equipment uses phased array antenna beam scanning to achieve spatial coverage. Signal detection and spectrum processing have the problem of merging between scanning beams. Figure 6 Describe the merger process.

[0095] A parallel strategy is used for the four spectrum segments. Each frequency band is divided into spectrum scanning and narrowband control and monitoring. Spectrum scanning is used for coarse detection of full-bandwidth signals. The center frequency and bandwidth of the signal are calculated based on the threshold and the spectrum. First, a single-sided scan is performed. For example, if a single-sided scan is performed at an interval of 8° and 90°, then the single side needs to be scanned at least 12 times. The maximum value of the 12 spectra is taken to obtain the single-sided synthetic spectrum. After scanning the four sides in sequence, four groups of spectrum signals are obtained. The signal processing unit uploads the four groups of spectrum signals to the display and control computer. The display and control computer takes the maximum value of the four groups of spectra to obtain the final spectrum data, and displays the spectrum on the interface. The spectrum data is manually or automatically detected as needed, and the next step of control and monitoring analysis is performed on the signal of interest.

[0096] The above steps complete coarse signal detection based on spectrum information. When further modulation identification or direction finding is required, the next step is narrowband control and monitoring. The spectrum scanning step determines the signal's center frequency and bandwidth. The signal processing unit's narrowband DDC is configured based on the frequency and bandwidth. A 360° omnidirectional scan is required for the first control and monitoring. The signal processing unit selects the highest-power IQ group for modulation identification, parameter measurement, and direction finding. Subsequent continuous control and monitoring of the signal can be performed directly using the previous beam, eliminating the need for a new beam search. The control and monitoring measurement results are uploaded to the display and control software, which updates the signal list.

[0097] The following describes the interference source identification, testing, and early warning for the ground station's electromagnetic environment.

[0098] Interference sources:

[0099] Interference in satellite communication systems mainly comes from human interference, equipment failure, and natural phenomena. Common interference signal types include conventional modulated carriers, single carriers, swept frequency signals, co-channel interference, spurious waves, and time-division signals.

[0100] a) Conventional modulated wave signal

[0101] Conventional modulated waves primarily refer to carrier waves modulated using frequency division multiple access (FDMA) technology, such as QPSK, BPSK, and MSK. Due to its simple equipment, ease of implementation, and stable signals, FDMA is the earliest and most widely used multiple access method in satellite communication systems.

[0102] Typical conventional modulated interference signals have relatively stable parameters such as frequency, bandwidth, and power. This interference is usually caused by individuals or organizations illegally occupying satellite resources for their own communications purposes without the satellite operator's permission. Alternatively, users may accidentally transmit signals to the satellite at frequencies or times when they shouldn't, disrupting normal onboard services. This is called clutter interference.

[0103] Processing flow:

[0104] This invention utilizes a "signal acquisition - interference identification - precise location - early warning reporting" process to achieve automated identification and rapid response to interference signals. Monitoring equipment receives signals, and an interference recognition algorithm identifies the interference signal, accurately distinguishing the interference type. Direction-finding is performed on the identified interference signal, accurately measuring its azimuth and elevation angles. Finally, an early warning is issued for the detected interference signal, serving as crucial evidence in proving interference.

[0105] a) Signal acquisition

[0106] The monitoring function of the monitoring equipment selects the monitoring antenna to collect electromagnetic environment interference signals. The electromagnetic wave signals received by the monitoring antenna are sent to the broadband RF receiver, which down-converts the electromagnetic wave signals to 768MHz intermediate frequency signals.

[0107] b) Interference identification

[0108] The baseband module acquires the intermediate frequency (IF) signal, performs digital down-conversion in the DDC, generates the signal's spectrum in the FFT module, and then stores the spectrum data in a spectrum data storage device. The module reads the spectrum data from the database and uses interference recognition algorithms targeting interference from terrestrial wireless communications (4G and 5G), radar signals, drone signals, and other satellite signals to determine whether the acquired signal is an interference signal. If it is not, the data is archived. If it is an interference signal, the module extracts signal features, identifies the signal modulation method, and classifies the interference signal into its specific category. The interference signal type is stored in the interference signal feature library and displayed on the display module.

[0109] c) Precise positioning

[0110] For the identified interference signal, the device selects the direction-finding antenna, controls the narrowband RF receiver to tune to the specified frequency point, sends the signal of each antenna element to the 1GHz~21.5GHz narrowband RF receiver, down-converts the signal to an intermediate frequency signal, and the signal processing unit performs A / D acquisition on the intermediate frequency signal, and then performs digital processing such as DDC filtering and FFT. Finally, the main control module performs direction-finding calculations to obtain the incident direction of the signal.

[0111] d) Early warning reporting

[0112] After finding the direction of the interference signal, an interference analysis report (including signal characteristics, modulation mode, interference type, signal direction, etc.) is generated for early warning reporting. It supports historical interference playback and provides dynamic electromagnetic environment perception data for interference signal monitoring and electromagnetic environment situation display.

[0113] Functional design:

[0114] The system monitors a set frequency band over a long period of time, automatically detecting suspicious and abnormal signals and issuing timely warnings or alarms. The system uses various thresholds (sample / fixed / automatic) to screen out suspicious signals, then performs intermediate frequency (IF) measurement, IF direction finding, audio and video monitoring, and pattern recognition. It then identifies these signals using a signal library and interference identification algorithms. If known signals experience significant changes in strength or bandwidth, modulation mode, or the appearance of unknown or new signals, prompts an alarm and notifications are sent to the client. The system records and collects evidence of these illegal transmissions, accumulating data over time to form a signal library. This data is then analyzed to identify patterns of violations, providing early warnings and focused testing of these signals during subsequent mission execution.

[0115] This function is implemented in two ways: 1) real-time monitoring; 2) unattended automatic monitoring. Real-time monitoring has higher authority than unattended automatic monitoring, meaning that real-time monitoring can disable unattended automatic monitoring at any time. Unattended automatic monitoring only starts when the device has no real-time tasks.

[0116] a) Real-time monitoring

[0117] Manually set the frequency band and related parameters in the client software and click the Start button to begin monitoring. If the threshold is a sample threshold, sample collection is required. The system uses various thresholds (sample, fixed, or automatic) to screen suspicious signals. It then performs intermediate frequency (IF) measurement, IF direction finding, audio monitoring, and pattern recognition, then integrates the signal library with interference identification algorithms for identification. If known signals experience significant changes in strength, bandwidth, modulation mode, or the appearance of unknown or new signals, prompts are issued and displayed on the client. Recorded signal information includes frequency, bandwidth, signal type, interference type, real-time amplitude / field strength, minimum amplitude / field strength, maximum amplitude / field strength, occupancy, direction of arrival, spectrum, IQ, audio frequency, number of captures, and the latitude and longitude of the test point.

[0118] b) Unmanned automatic monitoring:

[0119] After presetting frequency bands and related parameters in the system, the monitoring device is powered on and automatically monitors when no real-time monitoring tasks are in place. This means that once a task is assigned, the system automatically starts monitoring, scanning the preset frequency band and collecting sample data. During the monitoring process, it automatically identifies suspicious signals and compiles a list. It then performs intermediate frequency (IF) measurement, IF direction finding, audio monitoring, and pattern recognition, then integrates the signal library with interference identification algorithms for further identification. If known signals experience significant changes in strength or bandwidth, modulation mode, or the appearance of unknown or new signals, a timely warning is generated and the client is notified. Signal information recorded includes frequency, bandwidth, signal type, interference type, real-time amplitude / field strength, minimum amplitude / field strength, maximum amplitude / field strength, occupancy, direction of arrival, spectrum, IQ, audio frequency, number of captures, and the latitude and longitude of the test point. This entire process requires no human intervention, significantly improving the system's automation.

[0120] c) Sample Library

[0121] The terminal runs a frequency band scan to collect samples of the maximum value of the signal spectrum, and the samples can be edited manually.

[0122] d) Signal library

[0123] During real-time monitoring, signals can be manually labeled and injected into the signal library, and station signals can be imported into the signal library in batches to form a basic signal library.

[0124] e) Early warning

[0125] The system records and collects evidence of these illegal transmission signals, accumulates data over a long period of time to form a signal library pool, studies and analyzes their illegal patterns, and provides early warnings and key testing of these signals during subsequent task execution.

[0126] The system interface of the present invention is described below.

[0127] System interface such as Figure 7 As shown:

[0128] Interface A is the interface between the operation control center and centralized monitoring. It accepts the task plan of the operation control center and receives the relevant information returned by centralized monitoring, such as electromagnetic environment data and equipment operating parameters.

[0129] Interface B is the interface between the centralized monitoring and information processing terminal, which receives the centralized monitoring task plan, issues instructions and returns electromagnetic environment data, equipment operating parameters, etc.

[0130] The C interface is the interface between the timing equipment and the system equipment, which transmits timing information, and the transmission content is the time and frequency reference signal.

[0131] The O interface is the interface between the information processing terminal center and the radio frequency receiving unit, which transmits the monitoring instructions to the radio frequency receiving unit.

[0132] The P interface is the interface between the RF receiving unit and the signal processing unit, and transmits the processed intermediate frequency signal to the signal processing unit.

[0133] The Q interface is the interface between the signal processing unit and the information processing terminal, and sends the relevant interfaces after signal feature processing, signal parameter measurement, modulation system and feature recognition processing to the information processing terminal.

[0134] External interface:

[0135] a) Information interface

[0136] The ground station electromagnetic environment monitoring system receives the distribution information and instructions of the centralized monitoring center, and the centralized monitoring receives the electromagnetic environment data, equipment working parameters, etc. transmitted back from the ground station electromagnetic environment monitoring system.

[0137] The foregoing description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Rather, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the concept described herein through the above teachings or techniques or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be protected by the appended claims.

Claims

1. A full-band satellite ground station electromagnetic environment monitoring system, characterized in that: include: Monitoring and direction-finding subsystem and information processing subsystem. The full-band satellite ground station electromagnetic environment monitoring system is deployed in the StarNet information gateway station. The monitoring and direction-finding subsystem includes omnidirectional real-time monitoring equipment and directional high-sensitivity monitoring equipment. The omnidirectional real-time monitoring equipment and directional high-sensitivity monitoring equipment are installed outdoors through fixed brackets and connected to indoor equipment. The omnidirectional real-time monitoring equipment and the directional high-sensitivity monitoring equipment receive interference signals through the corresponding monitoring antennas and direction-finding antennas, and send the received interference signals to the corresponding RF receivers. The RF receiver antennas filter, amplify, and frequency-convert the received signals, then output intermediate frequency signals and send them to the corresponding signal processing units. The omnidirectional real-time monitoring equipment's monitoring antennas include 1-18 GHz and 18-47 GHz antennas, and the direction-finding antenna arrays include 1-3 GHz, 3-8 GHz, and 8-21.5 GHz direction-finding antenna arrays. The RF receivers include broadband and narrowband RF receivers. When performing monitoring tasks, the monitoring antenna is selected according to the system settings, and the electromagnetic wave signal received by the monitoring antenna is sent to the broadband RF receiver. The broadband RF receiver down-converts the electromagnetic wave signal into an intermediate frequency signal. The corresponding signal processing unit completes the digital processing of the intermediate frequency signal and sends the processing result to the display and control computer for display and processing, completing the measurement of signal frequency, level, and bandwidth, as well as intermediate frequency spectrum analysis and scanning functions. The monitoring direction-finding antenna, L / S, C, Ka, Q / V radio frequency receivers, and corresponding signal processing units of the directional high-sensitivity monitoring equipment are integrated in the antenna cover. When the interference signal investigation and handling task is performed by the directional high-sensitivity monitoring equipment, the monitoring direction-finding antenna of the corresponding frequency band is selected according to the system settings, and each monitoring direction-finding antenna of the frequency band is switched one by one through the radio frequency switch. The monitoring direction-finding antenna stays at a set time to search for the signal, and the electromagnetic wave signal received by the monitoring direction-finding antenna is sent to the L / S, C, Ka, Q / V radio frequency receiver, down-converted into an intermediate frequency signal, and the corresponding signal processing unit completes the digital processing of the intermediate frequency signal, and the processing result is sent to the monitoring direction-finding software for display and processing, so as to realize spectrum scanning to find the interference signal, identify the interference signal, store the processed data and send the relevant results to the display and control computer; The corresponding signal processing unit samples the input signal and performs down-conversion, filtering, and extraction pre-processing operations according to the specified frequency, and completes the FFT and signal search and detection functions. It analyzes and monitors the direction-finding of the pre-processed data, and transmits the monitoring direction-finding data to the information processing subsystem; The information processing subsystem receives the monitoring results from the ground station and performs integrated statistical processing, including monitoring results, direction finding azimuth, and equipment status information, and finally completes the display of working parameters, data statistics, and equipment status.

2. The full-band satellite ground station electromagnetic environment monitoring system according to claim 1, characterized in that: The omnidirectional real-time monitoring device receives instructions from the display and control computer of the information processing subsystem, performs signal monitoring tasks and target signal lateral tasks, and when performing the signal monitoring task, selects the monitoring antenna according to the system settings, and sends the electromagnetic wave signal received by the monitoring antenna to the broadband radio frequency receiver of the omnidirectional real-time monitoring device. The broadband radio frequency receiver down-converts the electromagnetic wave signal into an intermediate frequency signal, and the signal processing unit of the omnidirectional real-time monitoring device completes the digital processing of the intermediate frequency signal, and sends the processing result to the display and control computer for display and processing, completing the measurement of the signal frequency, level, and bandwidth, as well as the intermediate frequency spectrum analysis and scanning functions.

3. The full-band satellite ground station electromagnetic environment monitoring system according to claim 2, characterized in that: When performing the target signal direction-finding task, the narrowband RF receiver of the omnidirectional real-time monitoring equipment is controlled to tune to the specified frequency point, and the 1-3GHz, 3-8GHz, and 8-21.5GHz direction-finding antennas are selected. The RF switching switch of the omnidirectional real-time monitoring equipment is used for switching, and the signals of each antenna element are sent to the 1-3GHz, 3-8GHz, and 8-21.5GHz dual-channel RF receivers in sequence. The signals are down-converted to intermediate frequency signals. The signal processing unit of the omnidirectional real-time monitoring equipment performs A / D acquisition on the intermediate frequency signals, and then performs DDC filtering and FFT digital processing. Finally, direction-finding calculations are performed to obtain the incident azimuth of the signal.

4. The full-band satellite ground station electromagnetic environment monitoring system according to claim 1, characterized in that: The directional high-sensitivity monitoring equipment adopts an integrated design. The monitoring direction-finding antenna, L / S, C, Ka, Q / V radio frequency receivers, and signal processing unit of the directional high-sensitivity monitoring equipment are integrated in its own antenna cover. The directional high-sensitivity monitoring equipment receives instructions from the display and control computer and performs the task of investigating and handling interference signals. When performing the task of investigating and handling interference signals, the monitoring and direction-finding antenna of the corresponding frequency band is selected according to the system settings, and each monitoring and direction-finding antenna of the frequency band is switched one by one through the RF switching switch of the directional high-sensitivity monitoring equipment. A set time is set for each monitoring and direction-finding antenna to search for the signal. The monitoring and direction-finding antenna sends the received electromagnetic wave signal to the L / S, C, Ka, Q / V RF receiver, down-converts it into an intermediate frequency signal, and the signal processing unit of the directional high-sensitivity monitoring equipment completes the digital processing of the intermediate frequency signal, and sends the processing result to the monitoring and direction-finding software of the directional high-sensitivity monitoring equipment for processing, so as to realize spectrum scanning to find interference signals, identify interference signals, store the processed data and send relevant results to the display and control computer.

5. The full-band satellite ground station electromagnetic environment monitoring system according to claim 1, characterized in that: The directional high-sensitivity monitoring equipment uses phased array antenna beam scanning to achieve airspace coverage. The four spectrum segments adopt a parallel strategy. Each spectrum segment is divided into spectrum scanning and narrowband control and monitoring. Spectrum scanning is used for coarse detection of full-bandwidth signals. The center frequency and bandwidth of the signal are calculated based on the threshold and the spectrum. First, multiple scans are performed on a single side. The maximum value of the spectrum obtained from multiple scans of a single side is taken as the spectrum signal of that single side. Then, after scanning other sides in turn, four groups of spectrum signals are obtained and uploaded to the display and control computer. The display and control computer uses the maximum value of the four groups of spectrum as the final spectrum data. A 360° omnidirectional scan is performed for the first control through narrowband control and monitoring. The signal processing unit selects the IQ group with the largest power for modulation identification, parameter measurement and direction finding. The previous beam is used for direct monitoring of the signal for subsequent continuous control and monitoring.

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