An active jammer-to-signal ratio analysis method for aircraft radio communication

Abstract

This invention discloses a method for active interference signal-to-interference ratio (SIR) analysis of aircraft radio communications. The method includes: acquiring aircraft track data, ground station coordinate data, and interference source coordinate data, and mapping them uniformly to a three-dimensional coordinate system; obtaining the interference limit of the interference source at a reference distance and obtaining the reference interference field strength at the reference distance through correction processing; constructing a free-space propagation model of the active interference source, calculating the minimum distance between the aircraft's track point and the interference source, and obtaining the interference signal strength at the track point from the free-space propagation model; calculating the signal strength between the ground station and the aircraft at the track point, and calculating the SIR in decibels at the aircraft's airborne receiver at the track point. This invention can quickly generate SIR curves for interference assessment analysis of different interference sources on aircraft at different flight segments or different locations, significantly improving the accuracy and comprehensiveness of active interference analysis for airborne equipment.

Description

Technical Field

[0001] This invention relates to the field of civil aviation communication interference assessment, and more particularly to an active interference signal-to-interference ratio analysis method for aircraft radio communications. Background Technology

[0002] Airborne aviation radio equipment (hereinafter referred to as aircraft airborne equipment) is a key component of aircraft, mainly including aviation instruments, navigation equipment, communication equipment, radar equipment, and automatic control systems. It provides pilots with information such as flight status, position, and environmental parameters, and its functions encompass flight status monitoring, position positioning, environmental control, and safety assurance. Airborne aviation radio station equipment (also known as airborne equipment of ground stations) mainly includes navigation equipment, communication equipment, and surveillance equipment. It transmits signals and provides aircraft with information such as flight status, position, and navigation guidance, ensuring flight safety.

[0003] During flight, aircraft primarily rely on their onboard equipment to receive signals from ground stations (such as communication and navigation stations) in the airport terminal area for flight guidance. Therefore, ground stations (whose onboard equipment includes communication, navigation, and surveillance stations) are core infrastructure for aviation safety. However, during takeoff, departure, approach, and landing in the airport terminal area, aircraft fly at high speeds and low altitudes. If the signals received by the aircraft's onboard equipment are interfered with, it poses a serious threat to flight safety.

[0004] Airport terminal areas are characterized by a wide variety of radio interference sources with diverse interference mechanisms, and the forms of interference have evolved from narrowband electromagnetic interference to broadband electromagnetic interference. On one hand, besides common illegal high-power radio broadcasts and GPS signal jammers—instruments capable of independently transmitting radio signals—that can cause radio interference to aircraft onboard equipment, urbanization has also led to electromagnetic interference from electrified railways, overhead high-voltage power lines, and other electromagnetically sensitive sources that easily generate electromagnetic radiation. These sources can seriously threaten flight safety. Active interference sources mainly include equipment that emits electromagnetic waves, such as high-voltage overhead power lines and electrified railways. Currently, methods for determining interference values ​​without identifying interference sources cannot accurately assess the actual interference to airborne receivers. The usual approach involves converting airport-published aeronautical charts (i.e., nominal flight tracks) into CAD data. Based on the positional relationship between the nominal flight track and high-voltage power lines, the point closest to the interference source is selected for analysis and calculation. The interference signal from the active interference source to the airborne equipment of the ground station (also known as the airborne equipment of the aviation radio station) is compared with the useful signal received by the aircraft's airborne equipment at that location to determine whether the difference between the useful signal and the interference signal meets the protection ratio requirements (the minimum ratio of the signal field strength at the receiving point to the interference field strength of the same frequency channel at the receiving point that ensures the normal operation of the airborne equipment of the aviation radio station) in relevant standards and specifications such as GB6364-2013. The main drawbacks of the existing methods are: (1) The existing methods cannot fuse the interference signals of the interference source, the actual flight data of the aircraft (including QAR data, ADS-B data and secondary radar station data), and the ground station of the airport aviation radio station; (2) The theoretical flight track and altitude of the aircraft in the airport published aeronautical chart are used, but there is a certain difference between the actual flight track and the theoretical flight track, which leads to a deviation in the analysis of the interference of the aircraft's airborne equipment; (3) When selecting a specific evaluation point, it is impossible to determine that the difference between the useful signal and the interference signal at that point is the smallest, so it is impossible to fully reflect the interference situation of the airborne equipment during the entire departure, arrival or approach process; (4) The result of the interference analysis is only the analysis value of one point, lacking an intuitive visualization means of the interference situation during the entire flight process of the aircraft, and it is difficult to quickly determine whether the interference received by the airborne receiver meets the regulatory requirements.

[0005] The current technology has the following drawbacks: (1) Existing methods cannot integrate the interference signals of the interference source, the flight data of the aircraft (including QAR data, ADS-B data and secondary radar station data), and the ground stations of the airport aviation radio station on the same platform. It cannot intuitively integrate the location of the aviation radio ground station, the active interference source and the aircraft flight trajectory into a single map based on the GIS information system. (2) The theoretical flight trajectory and altitude of the aircraft in the airport published aeronautical chart are used, but there is a certain difference between the actual flight trajectory and the theoretical flight trajectory, which leads to a deviation in the analysis of interference received by the airborne receiver. (3) When selecting a specific evaluation point, it is not possible to accurately determine that the difference between the useful signal and the interference signal at that point is the smallest. Therefore, it is impossible to reflect the interference received by the airborne equipment during the entire departure, arrival or approach process. (4) The results of the interference analysis lack intuitive visualization methods, making it difficult to quickly determine whether the interference received by the airborne receiver meets the regulatory requirements. To address the problems with existing technologies, there is an urgent need for an active interference signal-to-interference ratio (AIR) analysis technique. This technique can analyze the interference signals from active interference sources such as high-voltage overhead power lines and electrified railways to assess the potential interference aircraft may experience during actual flight. It can visually display the positional relationship between the interference source and the aircraft's entire flight trajectory, and present the difference between the signal strength received by the aircraft's onboard receiver from ground equipment and the interference signal strength generated by the active interference source as a curve throughout the flight. This curve can also be compared with the protection rate required by regulations and displayed on a single graph, allowing for a more intuitive assessment of the interference experienced by the airborne receiving equipment of aviation radio stations. Summary of the Invention

[0006] The purpose of this invention is to provide an active interference signal-to-interference ratio (SIR) analysis method for aircraft radio communications. This method can quickly generate SIR curves for interference assessment analysis of different interference sources on aircraft at different flight segments or locations. It can intuitively determine whether the interference to aircraft onboard equipment meets the requirements, and can trace and locate the location point most affected by interference. This significantly improves the accuracy, comprehensiveness, and practicality of active interference analysis for onboard equipment, providing reliable technical support for aviation flight safety.

[0007] The objective of this invention is achieved through the following technical solution: An active interference signal-to-interference ratio (SINR) analysis method for aircraft radio communications, the method comprising: S1. Acquire the aircraft's trajectory data, ground station coordinate data, and interference source coordinate data, and map them uniformly to a three-dimensional coordinate system; S2. Obtain the location of the interference source at the reference distance. The interference limit at the reference distance is obtained by correcting the interference source. Reference interference field strength at the location ; S3. Construct a free-space propagation model for active interference sources and calculate the aircraft's trackpoint. Minimum distance from interference source The free-space propagation model obtains the waypoints according to the following formula. Interference signal strength : ; S4. Calculate and obtain ground stations and track points. Signal strength between aircraft The waypoints are obtained according to the following formula. Signal-to-interference ratio in decibels for aircraft airborne equipment : .

[0008] To better achieve the present invention, the present invention also includes the following methods: S5. Obtain the signal-to-interference ratio (SIR) of all flight path points of the aircraft according to methods S3 to S4, and store the flight path point location information and SIR in association to obtain a flight path SIR database.

[0009] Preferably, the present invention sets a reference point, calculates the distance from the track point to the reference point as the track point position information, and constructs a signal-to-interference ratio (SIR) curve that varies with the track point position using the track point position information as the abscissa and the signal-to-interference ratio (SIR) as the ordinate.

[0010] Preferably, in method S1, the method for obtaining aircraft track data is as follows: acquiring the latitude, longitude, and elevation coordinates of the same aircraft from ADS-B data, secondary radar data, QAR data, and ARNIC424 navigation data, performing three-dimensional track fitting to generate three-dimensional track data, setting the track sampling interval, and performing equal-interval sampling processing on the generated three-dimensional track data according to the track sampling interval.

[0011] Preferably, the method for generating three-dimensional track data based on fitting ADS-B data, secondary radar data, QAR data, and ARNIC424 navigation data is as follows: S11. Construct the parametric equations for the three-dimensional trajectory. The expressions for the parametric equations are as follows: Where (X, Y, Z) are assumed arbitrary points on a straight line in space, , , () is used as the reference point, and the geometric center of the scatter points is selected during the fitting process; Let be the direction vector of the three-dimensional trajectory, and t be a free parameter used to generate arbitrary points; its symmetric linear equation is as follows: The optimal fitted 3D trajectory is the one where the sum of the squared orthogonal distances from all scattered points to the spatial straight line is minimized. S12. Take the reference point as the geometric center of the multi-source data, which includes ADS-B data, secondary radar data, QAR data, and ARNIC424 navigation data. S13. Construct a centered covariance matrix M, and perform singular value decomposition on the covariance matrix M to obtain the optimal direction vector of the three-dimensional track. S14. Substitute the geometric center and optimal direction vector of the multi-source data into the symmetric straight line equation to obtain the three-dimensional trajectory data generated by the optimal fitting of the aircraft.

[0012] Preferably, in method S2, the interference source is an active interference source for communication between a ground station and an aircraft, and the interference source includes electrified railways and lines and high-voltage transmission lines; when the interference source is an electrified railway and line, the reference interference field strength is... The expression is as follows: , ,in This represents the bandwidth factor of the ground station. The reference bandwidth is the bandwidth corresponding to the ground station being measured. To test the resolution bandwidth of the system or equipment used to test the ground station under test. This is the conversion factor between peak detection and quasi-peak detection measurement results. For electrified railways and lines at the reference distance Interference limits at the location.

[0013] Preferably, when the interference source is a high-voltage transmission line, the reference interference field strength is... The expression is as follows: , For high-voltage transmission lines at the reference distance Interference limits at the location, This is the frequency correction value for interference field strength; for communication frequencies between ground stations and aircraft between 0.15 and 30 MHz, the frequency correction value for interference field strength is... The expression is as follows: , The target frequency is converted; for communication frequencies between ground stations and aircraft exceeding 30MHz, the interference field strength frequency correction value is... The expression is as follows: , Calculate the frequency for the target. is the antenna shape variation constant.

[0014] Preferably, in method S3, waypoints are selected. Nearby interference sources and their location data, where k is the sequence number of the waypoint on the aircraft's track, and the minimum distance. for waypoints with trackpoints The minimum distance between all nearby interference sources.

[0015] Preferably, in method S4, if the communication operating frequency between the ground station and the aircraft reaches 30MHz or higher, then the signal strength... The expression is as follows: , This refers to the transmission power of the ground station. This refers to the distance between the ground station and the aircraft; if the communication frequency between the ground station and the aircraft is less than 30MHz, then the signal strength... The expression is as follows: .

[0016] Preferably, the present invention sets a lower limit threshold for the signal-to-interference ratio (SIR) communication, expresses the lower limit threshold in the SIR curve, and displays the curve segments in the SIR curve where the SIR is less than the lower limit threshold; and filters and locates data where the SIR is less than the lower limit threshold as SIR alarm data output.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) Through the improvement of core technologies such as multi-source data fusion, three-dimensional trajectory fitting, accurate interference calculation and visualization, this invention can quickly generate interference assessment and analysis of different interference sources on aircraft at different flight segments or different locations to obtain signal-to-interference ratio curves. It can intuitively judge whether the interference to the aircraft's airborne equipment meets the requirements, and can trace and locate the location point most affected by interference. It significantly improves the accuracy, comprehensiveness and practicality of active interference analysis of airborne equipment, and provides reliable technical support for aviation flight safety. It can analyze the interference of various active interference sources (high-voltage transmission lines, electrified railways, etc.) on airborne equipment in real time or periodically and discover interference hazards in a timely manner, providing precise direction for interference control, providing data support and technical reference for aviation safety management and airborne equipment performance optimization, and has broad engineering application value.

[0018] (2) Based on multi-source data fusion technology, this invention fuses track data from ADS-B data, secondary radar data and flight QAR data after screening, and can obtain accurately fitted track data. It comprehensively analyzes the location data of active interference sources, interference signal strength data, location, frequency and power of ground stations, as well as the interference signal strength and useful signal strength received by the aircraft's airborne equipment, and obtains the results of the interference calculation of the aircraft in the actual flight trajectory caused by the active interference sources. It also generates a visualized curve, which makes it more intuitive to determine the interference situation in different flight segments or different locations, and makes the analysis results more intuitive.

[0019] (3) This embodiment is mainly applied to the interference assessment and analysis of existing interference sources. Of course, it can also be applied to the assessment and analysis of planned interference sources. By inputting the data of the planned interference source into the method of this invention for assessment and analysis, the trajectory signal-to-interference ratio database of the planned interference source to all flight path points of the aircraft can be obtained. The trajectory signal-to-interference ratio database can be used to optimize and adjust the planned path of the planned interference source. It can provide a basis for the location selection of active interference sources in the early stage of construction (provide a scientific basis for interference source site selection, reduce interference risk from the source, and ensure aviation flight safety), and can also provide technical means for aviation radio interference protection during airport flight operations, and also provide a guarantee for the safe operation of airport aircraft.

[0020] (4) This invention uses a dual-mode approach of standard limits and measured data to calculate the interference signal strength of active interference sources. It combines precise correction methods such as bandwidth factor correction, peak and quasi-peak conversion, and frequency correction to ensure the accuracy of the calculation of the reference interference field strength of the interference source. At the same time, based on the free space propagation model, it calculates the minimum distance between the interference source and the aircraft's three-dimensional coordinates to accurately obtain the actual interference signal strength of the airborne receiver at each point on the flight trajectory, solving the problem of rough interference signal strength calculation and large error in the prior art. This invention adopts the corresponding useful signal strength calculation model according to different operating frequency bands (≥30MHz, <30MHz), and combines the transmission power, frequency, location and other parameters of the ground station to accurately calculate the useful signal strength received by the airborne receiver, further improving the accuracy of the signal-to-interference ratio calculation and providing reliable data support for interference assessment. Attached Figure Description

[0021] Figure 1 This is a flowchart of the active interference signal-to-interference ratio analysis method of the present invention; Figure 2 This is a simplified schematic diagram illustrating the principles of information acquisition and signal strength classification in this embodiment. Figure 3 This is a schematic diagram of the emission limits for electrified railways in the embodiment; Figure 4This is a schematic diagram of the emission limits of the traction substation in the embodiment; Figure 5 This is a schematic diagram illustrating the impact of active interference sources on communication between the glide slope beacon ground station and the aircraft in the embodiment. Figure 6 This is a signal-to-interference ratio curve with the runway entrance as the reference point in the embodiment; Figure 7 This is an example diagram showing the location of the location with the greatest interference in the interference source spectrum in the embodiment. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to embodiments: Example like Figure 1 , Figure 2 As shown, an active interference signal-to-interference ratio (SINR) analysis method for aircraft radio communications includes the following steps: S1. Acquire aircraft track data, ground station coordinate data, and interference source coordinate data, and map them uniformly to a three-dimensional coordinate system. The aircraft track data is obtained as follows: The latitude, longitude, and elevation coordinates of the same aircraft are acquired from ADS-B data, secondary radar data, QAR data, and ARNIC 424 navigation data. Three-dimensional track data is then generated through three-dimensional track fitting. ADS-B data primarily includes aircraft position, altitude, heading, ground speed, vertical speed, call sign, and IACO identifier. This data mainly provides information about the aircraft's position during low- and high-altitude flight. Secondary radar station data primarily includes the aircraft's serial number, altitude, and direction. This data mainly provides information about the aircraft's position during low- and high-altitude flight. QAR data records hundreds or even thousands of different flight parameter data points of an aircraft during flight. These include various parameters, aircraft position information, and crew operations—data closely related to aircraft operation. After being parsed by ground-based decoding software, data such as the aircraft's status, attitude, altitude, and speed throughout the flight can be obtained. ARINC424 data, encoded according to the ARINC424 standard, is the primary information source and crucial basis for the Flight Management System (FMS) and Automatic Flight Control System (AFCS) flight operations, and is a vital component in ensuring aircraft operational safety. ARINC424 encoding includes core data crucial to flight operations, such as navigation facilities, airports, runways, routes, waypoints, approach and departure procedures, holding procedures, and restricted airspace.

[0023] The required data includes: airport runway data, aeronautical radio station data, aircraft flight data (i.e., ADS-B data, secondary radar surveillance data, and QAR data during aircraft flight), and data on interference sources. Airport runway data should include the runway threshold's latitude and longitude coordinates and elevation, runway length and width, true azimuth and magnetic deviation, etc. Aeronautical radio ground station data should include the station's latitude and longitude coordinates, ground elevation, antenna height, antenna type, operating frequency, power, etc. The actual three-dimensional flight path data of the aircraft, i.e., the location of the airborne aeronautical radio equipment, is obtained from the aircraft's ADS-B data, secondary radar data, and QAR data, i.e., the aircraft's latitude, longitude, and altitude data during flight. Interference source data should include the interference source's latitude, longitude, and elevation data. The acquired aircraft flight path data will be decoded, parsed, and preprocessed before being fused. The data preprocessing process mainly involves data denoising, abnormal data cleaning, and redundancy handling. For example, it removes dirty data such as outliers in aircraft position and altitude data, as well as abnormal data such as duplicate records in flight data.

[0024] The aircraft's track data, ground station coordinate data, and interference source coordinate data are uniformly mapped to a three-dimensional coordinate system. The latitude and longitude coordinates of the tracks from ADS-B data, secondary radar data, QAR data, and ARNIC 424 data are transformed into a three-dimensional coordinate system after Mercator projection (UTM projection). Then, the corresponding altitude data is recorded together as data in a three-dimensional coordinate system (X-axis: longitude coordinates via Mercator projection; Y-axis: latitude coordinates via Mercator projection; Z-axis: elevation). Therefore, the tracks in ADS-B data are transformed into coordinates... , ……., Secondary radar data track data conversion , ……., ; converting track coordinates in QAR data to , ……., Runway entrance coordinates converted to The coordinate transformation of ground stations will be introduced using VHF radio, LOC localizer, GP glide slope beacon, VOR omnidirectional radar, DME rangefinder, and SSR secondary surveillance radar as examples (of course, ground stations also include other equipment). The coordinates of VHF radio, LOC localizer, GP glide slope beacon, VOR omnidirectional radar, DME rangefinder, and SSR secondary surveillance radar are as follows: , , , , , etc. The coordinates of interference sources (airport high-voltage lines and railways, etc.) are converted to... , ... , where N is the location of the interference source, N=1,2,3…….

[0025] The method for generating 3D track data based on fitting ADS-B data, secondary radar data, QAR data, and ARNIC424 navigation data is as follows: S11. Construct the parametric equations for the three-dimensional trajectory. The expressions for the parametric equations are as follows: Where (X, Y, Z) are assumed arbitrary points on a straight line in space, , , () is used as the reference point, and the geometric center of the scatter points is selected during the fitting process. , Let be the direction vector of the three-dimensional trajectory (determining the direction of the straight line; proportional vectors are in the same direction), and t be the free parameter used to generate arbitrary points. Its symmetric linear equation is as follows: The optimal fitted 3D trajectory is the one where the sum of the squared orthogonal (perpendicular) distances from all scattered points to the spatial straight line is minimized.

[0026] S12. Take the reference point as the geometric center of the multi-source data in a certain data point region. This invention uses ADS-B data, SSR data (i.e., secondary radar data), and QAR data as examples. , , Where n is the number of aircraft position points in a certain data point area of ​​ADS-B data, m is the number of aircraft position points in a certain data point area of ​​SSR data, and I is the number of aircraft position points in a certain data point area of ​​QAR data. Multi-source data includes ADS-B data, secondary radar data, QAR data, and ARNIC 424 navigation data.

[0027] S13. Construct a centered covariance matrix M, where M is a matrix of (n+m+1)×3. .

[0028] Perform singular value decomposition (SVD) on the covariance matrix M: Where V is a 3×3 orthogonal matrix, and its first column vector is the direction vector. After SVD decomposition, the first column of V corresponds to the direction with the largest data variance, which is the optimal fitting direction of the three-dimensional track. Therefore, the optimal direction vector of the three-dimensional track is obtained.

[0029] S14. Substitute the geometric center and optimal direction vector of the multi-source data into the symmetric linear equation. This allows us to obtain the three-dimensional flight path data generated by the optimal fit of the aircraft.

[0030] S15. In this embodiment, ADS-B data, secondary radar station data, QAR data, and ARNIC424 navigation data (latitude, longitude coordinates, and altitude data) are fitted to generate a three-dimensional flight path. Since the time intervals recorded in ADS-B data, secondary radar data, and QAR data are different, in order to improve data accuracy, the ADS-B data, secondary radar station data, QAR data, and ARNIC424 navigation data (after preprocessing and projection transformation in the second step) are fitted to generate the aircraft's three-dimensional flight path. At the same time, a track sampling interval is set (e.g., a sampling interval of 500m), and the generated three-dimensional track data is sampled at equal intervals according to the track sampling interval.

[0031] S2. Obtain the location of the interference source at the reference distance. The interference limit at the reference distance is obtained by correcting the interference source. Reference interference field strength at the location The interference source is an active interference source for communication between ground stations and aircraft, including electrified railways and lines, and high-voltage transmission lines. When the interference source is an electrified railway and line, the reference interference field strength is... The expression is as follows: Since the interference source is electrified railway and lines, the reference interference field strength is... It can be represented as . ,in The bandwidth factor for ground stations is shown in Table 1 below. Table 1. Bandwidth Factor Data for Various Stations

[0032] The reference bandwidth is the bandwidth corresponding to the ground station being measured. To test the resolution bandwidth of the system or equipment used to test the ground station under test. This is the conversion coefficient between peak detection and quasi-peak detection measurement results. For electrified railways and lines at the reference distance The interference limits for electrified railways, specifically the interference signal strength limits at a distance of 10m from the open track system and traction substation within the frequency band of 0.15MHz to 1GHz, are specified in GB / T24338.2-2018 "Electromagnetic Compatibility of Rail Transit - Part 2: Emissions from the Whole Track System to the Outside World". Figure 3 and Figure 4 As shown in the figure, the interference value at a distance of 10m from the electrified railway at the corresponding operating frequency can be read from the emission limit value in the figure. 铁路 .

[0033] When the interference source is a high-voltage transmission line, the reference interference field strength is... The expression is as follows: Since the interference source is a high-voltage transmission line, the reference interference field strength is... It can be represented as . For high-voltage transmission lines at the reference distance The interference limits at 0.5 MHz are based on relevant standards and specifications such as GB15707-2017 "Limits for Radio Interference of High Voltage AC Overhead Transmission Lines" and DL / T5536-2017 "Design Specification for Protection Against the Impact of DC Overhead Transmission Lines on Radio Stations". The following table shows the signal strength at 0.5 MHz at a distance of 20 m from the projected location of the high voltage transmission line. The interference limits vary depending on the voltage level, with higher voltage levels having larger limits. Table 2 shows the radio interference limits for some AC overhead transmission lines (20 m from the projected location of the edge conductor, 0.5 MHz).

[0034] The frequency characteristics of radio interference from high-voltage transmission lines refer to the relationship between the radio interference field strength correction value and the frequency. Based on the operating frequencies of various communication and navigation stations used at civil aviation airports, the baseline radio interference field strength calculated for high-voltage transmission lines at 0.5MHz needs to be corrected according to the frequency characteristics. The operating frequency bands of ground stations (i.e., civil aviation ground radio stations) are shown in Table 3 below:

[0035] The frequency correction value for interference field strength is given for communication frequencies between ground stations and aircraft that are between 0.15 and 30 MHz. The expression is as follows: , The target frequency is converted. For communication frequencies between ground stations and aircraft exceeding 30MHz, the interference field strength frequency correction value is... The expression is as follows: , Calculate the frequency for the target. It is the antenna shape change constant (obtained from experimental measurements, with an 80% probability of being approximately 20 dB).

[0036] S3. Construct a free-space propagation model for active interference sources and select track points. Nearby interference sources and their location data, k is the sequence number of the waypoint on the aircraft's track, calculate the aircraft's waypoint. Minimum distance from interference source minimum distance for waypoints with trackpoints The minimum distance between all nearby interference sources. The free-space propagation model obtains the waypoint according to the following formula. Interference signal strength : , The reference interference field strength is E. If the interference source is an electrified railway or a high-voltage transmission line, and the analysis is performed using the interference limits specified in the regulations, this value is E. 0（铁路） and E 0（高压输电线） ; Using the reference distance, if the interference source is an electrified railway and interference limits are used for analysis, The value is 10m. If the interference source is a high-voltage transmission line and the interference limit is used for analysis, The value is 20m; if the interference source is analyzed using actual test interference, This represents the distance between the spectrum analyzer and the interference source during the actual measurement.

[0037] S4. Calculate and obtain ground stations and track points. Signal strength between aircraft The waypoints are obtained according to the following formula. Signal-to-interference ratio in decibels for aircraft airborne equipment : In some embodiments, if the communication operating frequency between the ground station and the aircraft reaches 30MHz or higher, the signal strength... The expression is as follows: , This refers to the transmission power of the ground station. Let be the distance between the ground station and the aircraft; then the further expression for the signal-to-interference ratio is as follows: .

[0038] If the communication frequency between the ground station and the aircraft is less than 30MHz, the signal strength will be... The expression is as follows: , This refers to the transmission power of the ground station. The distance between the ground station and the aircraft, such as Figure 5 As shown, the ground station uses the glide slope beacon GP as an example. Recorded as , The further expression for the signal-to-interference ratio is as follows: .

[0039] S5. Obtain the signal-to-interference ratio (SIR) of all aircraft trackpoints according to methods S3-S4, and store the trackpoint location information and SIR in association to obtain a track SIR database. This embodiment mainly uses an existing interference source as an example, but it can also be applied to the evaluation and analysis of planned interference sources. Input the data of the planned interference source into the method of this invention for evaluation and analysis to obtain the track SIR database of the planned interference source to all aircraft trackpoints. Use the track SIR database to optimize and adjust the planned path of the planned interference source. Preferably, this invention can set a reference point (with... Figure 6 For example, Figure 6 (The runway threshold is selected as the reference point). The distance from the trackpoint to the reference point is calculated as the trackpoint position information. A signal-to-interference ratio (SIR) curve is constructed with the trackpoint position information as the x-axis and the SIR as the y-axis, showing how the SIR changes with the trackpoint position. In some embodiments, the present invention can set a lower threshold for the SIR communication (see...). Figure 6 , Figure 6 A signal-to-interference ratio (SIR) lower limit threshold of 20 is selected. This threshold is represented in the SIR curve graph, and warnings are displayed for curve segments where the SIR is lower than the lower limit. Data with SIRs lower than the lower limit are selected and output as SIR alarm data. Based on the active interference calculation results of airborne equipment and the protection rates or maximum permissible interference field strengths or power requirements for different aviation radios given in GB6364-2013 and MH / T4046-2017, a two-dimensional visualization curve for active interference analysis is finally generated (e.g., ...). Figure 6 As shown in the figure, the horizontal axis represents the distance from the starting point (i.e., the reference point, which is the runway threshold in this example) on the flight segment, in meters. The vertical axis represents the signal-to-interference ratio (SIR) obtained by comparing the signal strength received by the aircraft's onboard receiver with the interference signal strength generated by the interference source over the entire flight segment, in dB. The minimum value is then displayed in the figure. Figure 6 The results of active interference analysis are visualized, allowing for an intuitive assessment of whether the interference from the source affects the airborne radio receiver and whether the requirements are met. It also provides a clear indication of the interference trend affecting the airborne radio receiver throughout the flight segment, and allows for rapid location of the aircraft experiencing the most interference. Furthermore, it can pinpoint and trace the location of the maximum interference location within the interference source's spectrum (see [link]). Figure 7 (Example).

[0040] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An active jammer-to-signal ratio analysis method for aircraft radio communications, characterized by: The methods include: S1. Acquire the aircraft's trajectory data, the coordinate data of the ground stations, and the coordinate data of the interference sources, and map them uniformly to a three-dimensional coordinate system; S2, obtaining the interference limit value of the interference source at the reference distance and obtaining the reference interference field strength of the interference source at the reference distance by correction processing ;​ S3, constructing a free space propagation model of the active jamming source, calculating the aircraft's track point the minimum distance between the aircraft and the jamming source The free space propagation model obtains the jamming signal strength of the track point according to the following formula : ;​ S4, calculating the signal strength between the ground station and the aircraft at the track point , obtaining the signal to interference ratio in decibels for the aircraft onboard equipment at the track point : .​​ 2. The active interference signal-to-interference ratio analysis method for aircraft radio communication according to claim 1, characterized in that: It also includes the following methods: S5. Obtain the signal-to-interference ratio (SIR) of all flight path points of the aircraft according to methods S3 to S4, and store the flight path point location information and SIR in association to obtain the flight path SIR database.

3. The active interference signal-to-interference ratio analysis method for aircraft radio communication according to claim 2, characterized in that: A reference point is set, and the distance from the track point to the reference point is calculated as the track point position information. A signal-to-interference ratio (SIR) curve is constructed with the track point position information as the x-axis and the SIR as the y-axis, which varies with the track point position.

4. The active interference signal-to-interference ratio analysis method for aircraft radio communication according to claim 1, characterized in that: In method S1, the aircraft track data is obtained as follows: the latitude, longitude and elevation coordinates of the same aircraft are obtained from ADS-B data, secondary radar data, QAR data and ARNIC424 navigation data, and three-dimensional track data is generated by fitting the three-dimensional track. The track sampling interval is set, and the generated three-dimensional track data is sampled at equal intervals according to the track sampling interval.

5. The active interference signal-to-interference ratio analysis method for aircraft radio communication according to claim 4, characterized in that: The method for generating 3D track data based on fitting ADS-B data, secondary radar data, QAR data, and ARNIC424 navigation data is as follows: S11. Construct the parametric equations for the three-dimensional trajectory. The expressions for the parametric equations are as follows: Where (X, Y, Z) are assumed arbitrary points on a straight line in space, , , () is used as the reference point, and the geometric center of the scatter points is selected during the fitting process; Let be the direction vector of the three-dimensional trajectory, and t be a free parameter used to generate arbitrary points; its symmetric linear equation is as follows: The optimal fitted 3D trajectory is the one where the sum of the squared orthogonal distances from all scattered points to the spatial straight line is minimized. S12. Take the reference point as the geometric center of the multi-source data, which includes ADS-B data, secondary radar data, QAR data, and ARNIC424 navigation data. S13. Construct a centered covariance matrix M, and perform singular value decomposition on the covariance matrix M to obtain the optimal direction vector of the three-dimensional track. S14. Substitute the geometric center and optimal direction vector of the multi-source data into the symmetric straight line equation to obtain the three-dimensional trajectory data generated by the optimal fitting of the aircraft.

6. The active interference signal-to-interference ratio analysis method for aircraft radio communication according to claim 1, characterized in that: In method S2, the interference source is an active interference source for communication between a ground station and an aircraft, and the interference source includes electrified railways and lines and high-voltage transmission lines; when the interference source is an electrified railway and line, the reference interference field strength is... The expression is as follows: , ,in This represents the bandwidth factor of the ground station. The reference bandwidth is the bandwidth corresponding to the ground station being measured. To test the resolution bandwidth of the system or equipment used to test the ground station under test. This is the conversion factor between peak detection and quasi-peak detection measurement results. For electrified railways and lines at the reference distance Interference limits at the location.

7. The active interference signal-to-interference ratio analysis method for aircraft radio communication according to claim 6, characterized in that: When the interference source is a high-voltage transmission line, the reference interference field strength is... The expression is as follows: , For high-voltage transmission lines at the reference distance Interference limits at the location, This is the frequency correction value for interference field strength; for communication frequencies between ground stations and aircraft between 0.15 and 30 MHz, the frequency correction value for interference field strength is... The expression is as follows: , The target frequency is converted; for communication frequencies between ground stations and aircraft exceeding 30MHz, the interference field strength frequency correction value is... The expression is as follows: , Calculate the frequency for the target. is the antenna shape variation constant.

8. The active interference signal-to-interference ratio analysis method for aircraft radio communication according to claim 1, characterized in that: In method S3, waypoints are selected. Nearby interference sources and their location data, where k is the sequence number of the waypoint on the aircraft's track, and the minimum distance. for waypoints with trackpoints The minimum distance between all nearby interference sources.

9. The active interference signal-to-interference ratio analysis method for aircraft radio communication according to claim 1, characterized in that: In method S4, if the communication operating frequency between the ground station and the aircraft reaches 30MHz or higher, then the signal strength... The expression is as follows: , This refers to the transmission power of the ground station. This refers to the distance between the ground station and the aircraft; if the communication frequency between the ground station and the aircraft is less than 30MHz, then the signal strength... The expression is as follows: .

10. The active interference signal-to-interference ratio analysis method for aircraft radio communication according to claim 3, characterized in that: Set a lower limit threshold for the signal-to-interference ratio (SIR) communication, and express the lower limit threshold in the SIR curve graph. Display the curve segments in the SIR graph where the SIR is less than the lower limit threshold as warnings. Filter and locate data where the SIR is less than the lower limit threshold as SIR alarm data output.

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