Radio interference equipment flight disturbance aviation radio equipment risk assessment method

Abstract

The present application belongs to the technical field of aviation radio safety evaluation, and proposes a kind of aviation radio equipment risk evaluation method for the navigation of radio countermeasure equipment disturbance, this method is for navigation, communication and monitoring aviation radio equipment, according to the working system, disturbed mechanism and operation performance requirement of different equipment, using "maximum allowed interference power threshold preliminary screening-signal-to-noise ratio and performance degradation calculation-operation performance or safety margin comparison-risk level output" technical route, the navigation risk of target equipment under the action of countermeasure interference is classified and quantified, which can effectively distinguish the risk state of insufficient protection but still running and dangerous misleading information or function failure, realize the consistency of cross equipment system evaluation output.

Description

Technical Field

[0001] This invention belongs to the field of aviation radio safety assessment technology, and in particular relates to a risk assessment method for aviation radio equipment that interferes with flight operations using radio countermeasures equipment. Background Technology

[0002] With the rapid development of the low-altitude economy, drone applications, and airspace activities around airports, violations of drone regulations, unauthorized drone flights, and other non-cooperative targets intruding into airport airspace protection zones, arrival and departure routes, and key sensitive areas occur frequently. To maintain the safety of airport and air route operations, practical engineering projects typically require the deployment of radio detection, suppression, decoy, or combined radio countermeasure equipment to identify, handle, and control relevant low-altitude targets.

[0003] However, when performing tasks such as target suppression, link disruption, or navigation jamming, the transmitted signals of radio countermeasures equipment often possess certain power, bandwidth, and spectral spread characteristics. In complex electromagnetic environments, in addition to affecting target UAVs, they may also have unintended impacts on aviation radio equipment involved in civil aviation operations. Especially in sensitive operational environments such as airport areas, terminal areas, and air routes, aviation radio equipment is numerous, complex in type, and has high performance requirements; any interference exceeding limits may affect flight safety.

[0004] Radio equipment used in civil aviation operations can generally be divided into three main categories: navigation, communication, and surveillance. Navigation equipment mainly includes Instrument Landing System (ILS), VOR (Voice of Orientation), Distance Measuring Instrument (DME), Global Navigation Satellite System (GNSS), Ground-Based Augmentation System (GBAS), and radio altimeter. Communication equipment mainly includes VHF and HF communication. Surveillance equipment mainly includes ADS-B, Secondary Surveillance Radar (SSR), Multipoint Positioning System (MLAT), and Tele-Cross-Air Collision Avoidance System (TCAS). These devices respectively undertake key functions such as aircraft approach and landing guidance, air-to-ground communication, surveillance and positioning, and collision avoidance warning. Their anti-interference performance and continuous operation capability are directly related to flight safety.

[0005] Existing standards and specifications typically target individual equipment types, providing requirements such as maximum permissible interference power, protection ratio, coverage area, minimum usable signal strength, or operational performance limits from a system function perspective. These can be used for protection design and compatibility analysis in single-device, single-scenario situations. However, when facing complex real-world scenarios such as airports and air routes, a unified quantitative assessment method for air traffic interference risk that can accommodate different equipment systems, interference types, propagation environments, and operational levels is still lacking. Particularly in the application scenarios of radio countermeasures equipment, there is an urgent need to establish an assessment model that can describe the spatial distribution of interference signals and also output risk levels based on the performance degradation mechanisms of aviation radio equipment itself, providing support for the deployment of countermeasures equipment, the setting of operational boundaries, and risk decision-making.

[0006] Existing methods for assessing navigational disturbance risks or performing electromagnetic compatibility analysis typically employ one of the following approaches: (1) The maximum permissible interference power threshold is used as the criterion, and only the interference power is compared to see if it exceeds the standard limit. (2) The protection ratio (D / U) is used as the criterion, and whether the fixed protection ratio requirement is met is taken as the risk conclusion; (3) Some systems are evaluated using a single performance index. For example, communication systems are evaluated based on bit error rate and packet error rate, while navigation systems are evaluated based on receiver sensitivity, probability of loss of lock or positioning error. (4) Static analysis based on ideal free space or a single propagation model is difficult to reflect the real disturbance situation in complex environments such as line-of-sight propagation, corner diffraction, roof diffraction, near-ground propagation, and line-of-sight / beyond-line-of-sight propagation of air routes.

[0007] While the aforementioned methods have some applicability to specific equipment or single scenarios, they struggle to simultaneously cover multiple types of aviation radio equipment, including ILS, VOR, DME, GNSS / GBAS, radio altimeters, VHF / HF, ADS-B, SSR, and TCAS. Furthermore, they cannot effectively distinguish and classify intermediate states such as "interference power exceeds limits but the system can still maintain operation," "protection ratio fails but operational accuracy has not exceeded limits," and "safety margin is compromised but the system has not completely failed." Therefore, existing technologies cannot yet meet the practical needs of unified, dynamic, and quantifiable assessment of the interference risks from radio countermeasures equipment in airport UAV countermeasures, low-altitude safety protection, and complex civil aviation operation scenarios. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention proposes a risk assessment method for aviation radio equipment that interferes with navigation using radio countermeasures devices. The method aims to solve the following technical problems in existing technologies: the inability to establish a unified risk quantification model for different types of aviation radio equipment; the inability to distinguish between two risk states: "insufficient engineering protection but acceptable operational accuracy" and "dangerous misleading information / functional failure"; the inability to incorporate operational requirements such as operational level, navigation accuracy limits, and safety margins into risk classification; and the inability to perform consistent quantification calculations for various interference types, including co-channel, adjacent channel, blocking, and intermodulation.

[0009] The technical solution of the present invention is as follows: A risk assessment method for aviation radio equipment that interferes with flight operations using radio countermeasures includes the following steps: Step S0: Obtain the type and parameters of the jammed aviation radio equipment, wherein the types of aviation radio equipment include navigation, communication and surveillance. Step S1: Set the parameters of the radio countermeasures device and determine the type of interference; Step S2: Calculate the interference power of the receiver of the interfered aviation radio equipment according to the type of aviation radio equipment and the type of interference; Step S3: Based on the interference power, perform a level-one risk assessment. If a level-one risk exists, proceed to step S4; otherwise, determine that there is no risk and proceed to step S5. Step S4: Based on the type of aviation radio equipment, conduct a secondary risk assessment to obtain the final air traffic disturbance risk assessment result; Step S5: Output the flight disturbance risk assessment results for aviation radio equipment.

[0010] Preferably, in step S0, Navigation systems include Instrument Landing Systems (ILS), VOR (Voyager Orbit), Distance Measuring Instruments (DME), Global Navigation Satellite Systems (GNSS), and Ground-Based Augmentation Systems (GBAS). Communication categories include Very High Frequency (VHF) communication and High Frequency (HF) communication. Surveillance systems include Automatic Dependent Surveillance-Broadcast (ADS-B), Secondary Surveillance Radar (SSR), Multipoint Positioning System (MLAT), and Telematics and Collision Avoidance System (TCAS).

[0011] Preferably, the parameters of the aviation radio equipment in step S0 include the operating frequency band, reference bandwidth, maximum permissible interference power threshold, protection ratio threshold, operating accuracy limit, and operating class.

[0012] Preferably, step S1 specifically includes: Step S1-1: Set the parameters of the radio countermeasure equipment, including center frequency, bandwidth, transmit power, antenna gain and modulation scheme; Step S1-2: Based on the frequency difference between the center frequency of the radio countermeasure equipment and the operating frequency band of the interfered aviation radio equipment, determine the type of interference as co-channel interference, adjacent channel interference, blocking interference, broadband interference, harmonic interference, or intermodulation interference.

[0013] Preferably, step S2 specifically includes: For co-channel interference, adjacent channel interference, blocking interference, and harmonic interference, the interference power at the receiver of the aviation radio equipment is calculated based on the aforementioned transmit power, antenna gain, and propagation path loss model. I The propagation path loss model is selected based on the operating frequency, equipment height, and application scenario, including the ITU-R P.526 diffraction loss model, the ITU-R P.528 line-of-sight / beyond-line-of-sight and atmospheric absorption model, and the Two-Ray ground reflection model in ICAO Doc 9718.

[0014] For broadband interference, the equivalent interference power within the reference bandwidth of the aviation radio equipment receiver is calculated as the interference power. I ; For intermodulation interference, a third-order intermodulation model is used to calculate the power of the intermodulation products and convert it into the interference power at the receiver of the aviation radio equipment. I .

[0015] Preferably, the expression for the third-order intermodulation model is:

[0016] in, , For input interference power, It is a 3rd order intercept point.

[0017] Preferably, step S3 specifically includes: Determine whether the interference power is greater than the maximum permissible interference power threshold of the aviation radio equipment. If so, determine that there is a level 1 risk and proceed to step S4; otherwise, determine that there is no risk and proceed to step S5.

[0018] Preferably, in step S4, the secondary risk assessment process for ILS is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) Calculate the DDM deviation based on the risk quantification model of the DDM deviation; (3) Determine whether the DDM deviation is within the operating level limit. If it is, it is determined to be low risk; otherwise, it is determined to be high risk.

[0019] Preferably, in step S4, the secondary risk assessment process for VOR is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) Calculate the azimuth error based on the risk quantification model of azimuth error; (3) Determine whether the azimuth error exceeds the allowable upper limit. If so, it is determined to be high risk; otherwise, it is determined to be low risk.

[0020] Preferably, in step S4, the secondary risk assessment process for DME is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) Calculate the ranging error based on the risk quantification model of ranging error; (3) Determine whether the ranging error exceeds the allowable upper limit. If so, it is determined to be high risk; otherwise, it is determined to be low risk.

[0021] Preferably, in step S4, the secondary risk assessment process for GNSS and GBAS is as follows: (1) Calculate the interference power I Exceedance of the maximum permissible interference power threshold ; (2) If If it is low risk; if If so, it is judged as high risk.

[0022] Preferably, in step S4, the secondary risk assessment process for communication-related aviation radio equipment is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) Determine whether the signal-to-interference ratio is not lower than the MH threshold. If yes, it is determined to be risk-free. If no, determine whether the signal-to-interference ratio is higher than the ICAO threshold. If yes, it is determined to be low risk. Otherwise, it is determined to be high risk.

[0023] Preferably, in step S4, the secondary risk assessment process for surveillance-type aviation radio equipment is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) If the signal-to-interference ratio can maintain pulse detectability, it is judged as low risk; otherwise, it is judged as high risk.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The aviation radio equipment risk assessment method for interference with air traffic proposed in this invention can be applied to a unified air traffic interference risk quantification framework for three types of aviation radio equipment: navigation, communication, and surveillance, and can achieve consistent assessment output across equipment systems.

[0025] 2. The risk assessment method for aviation radio equipment that interferes with flight by radio countermeasures proposed in this invention introduces a three-level judgment mechanism of "maximum permissible interference power threshold + signal-to-interference ratio performance degradation model + operational level limit", which can effectively distinguish between the risk state of insufficient protection but still operable and the risk state of having dangerous misleading information or functional failure.

[0026] 3. The risk assessment method for aviation radio equipment that interferes with navigation proposed in this invention provides a risk quantification method based on DDM deviation for ILS, which can identify potential dangerous misleading information risks even when the receiver has not lost lock.

[0027] 4. The risk assessment method for aviation radio equipment that interferes with navigation proposed in this invention proposes a mapping model from signal-to-interference ratio to azimuth error / range measurement error for VOR and DME, thereby quantifying the risk of accuracy degradation.

[0028] 5. The aviation radio equipment risk assessment method proposed in this invention for interference with air traffic by radio countermeasures equipment introduces a safety margin classification for GNSS / GBAS, so that the assessment results take into account both conservatism and engineering interpretability.

[0029] 6. The aviation radio equipment risk assessment method proposed in this invention for interference with air traffic by radio countermeasures introduces dual criteria of MH threshold and ICAO threshold for communication equipment, which can distinguish between communication quality degradation and communication interruption risk.

[0030] 7. The aviation radio equipment risk assessment method for air traffic interference proposed in this invention can directly support the assessment of countermeasure equipment deployment, airport electromagnetic environment management, air traffic interference risk early warning and flight safety decision-making. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly introduced below. The features and advantages of the present invention can be more clearly understood by referring to the accompanying drawings. The accompanying drawings are schematic and should not be construed as limiting the present invention in any way. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart of the aviation radio equipment risk assessment method for interference with air traffic by radio countermeasures equipment, as per the present invention.

[0033] Figure 2 This is a schematic diagram for identifying interference types.

[0034] Figure 3 This is a flowchart of the ILS interference risk quantification process.

[0035] Figure 4 This is a flowchart of the VOR interference risk quantification process.

[0036] Figure 5 This is a flowchart of the DME interference risk quantification process.

[0037] Figure 6 This is a schematic diagram of dual-threshold determination for communication devices.

[0038] Figure 7 This is a diagram illustrating the risk classification of surveillance equipment. Detailed Implementation

[0039] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0041] This invention proposes a risk assessment method for aviation radio equipment that interferes with flight operations due to radio countermeasures. This method applies to navigation, communication, and surveillance aviation radio equipment, taking into account the different operating modes, interference mechanisms, and operational performance requirements of each type of equipment, such as... Figure 1 As shown, the technical approach of "initial screening of maximum permissible interference power threshold - calculation of signal-to-interference ratio and performance degradation - comparison of operational performance or safety margin - risk level output" is adopted to conduct a graded and quantitative assessment of the navigation disturbance risk of target equipment under counter-interference.

[0042] Example 1: Quantitative Assessment of ILS Disturbance Risk This embodiment focuses on the localizer, glide slope beacon, and marker beacon receivers in an Instrument Landing System (ILS) to quantitatively assess the risk of navigation interference caused by radio countermeasures equipment. This verifies the applicability of the invention to analog navigation systems. Specifically, as follows... Figure 3 As shown.

[0043] Step S0: Experimental subjects and general parameter settings ILS was selected as the target of interference, with the heading beacon receiver operating in the 108–111.975 MHz frequency band, a reference bandwidth of 3 kHz, and a maximum permissible interference power of [missing value]. 95 dBm; the glide slope beacon receiver operates in the 328.6–335.4 MHz frequency band, with a reference bandwidth of 3 kHz, and a maximum permissible interference power of [missing value]. 75 dBm; the pointing beacon receiver operates in the 74.8–75.2 MHz frequency band, with a reference bandwidth of 3 kHz, and a maximum permissible interference power of [missing value]. 66 dBm.

[0044] Input parameters such as the center frequency, bandwidth, transmit power, and transmit antenna gain of the radio countermeasures equipment, and combine them with the aircraft approach trajectory point set and propagation path loss model to establish disturbance analysis scenarios at various locations during the aircraft's movement along the approach trajectory.

[0045] For ILS, the first step is to determine whether the aircraft is within the signal coverage area of ​​the corresponding ILS. If the aircraft is not within the coverage area, the current scenario is considered not to meet the prerequisite for ILS interference risk quantification, and the calculation is terminated. If the aircraft is within the coverage area, the subsequent interference risk analysis steps are then performed.

[0046] S1: Interference Type Identification and Receiver Interference Power Calculation S1.1: Based on the frequency deviation between the center frequency of the radio countermeasures equipment and the operating frequency of the ILS, determine the type of interference as co-channel interference, adjacent channel interference, blocking interference, harmonic interference, or intermodulation interference, such as... Figure 2 As shown.

[0047] S1.2: For co-channel interference, adjacent-channel interference, blocking interference, and harmonic interference, calculate the interference power at the input of the ILS receiver at each position along the aircraft's approach track based on the interference source's transmit power, transmit antenna gain, and propagation path loss model. (Unit: dBm).

[0048] The propagation path loss model is selected based on the operating frequency, equipment height, and application scenario, including the ITU-RP.526 diffraction loss model, the ITU-RP.528 line-of-sight / beyond-line-of-sight and atmospheric absorption model, and the Two-Ray ground reflection model in ICAO Doc 9718.

[0049] S1.4: For broadband interference, calculate its equivalent interference power within the reference bandwidth of the ILS receiver as the interference power; for intermodulation interference, third-order intermodulation is the main factor. Calculate the intermodulation product power based on the input third-order intercept point parameters and convert it into the interference power at the receiver.

[0050] S1.5: Calculate the interference power The interference power is compared with the maximum permissible interference power threshold of the corresponding ILS as the basis for primary risk screening. If the interference power... If the threshold is not exceeded, it is determined that there is no significant risk of flight disruption; if the interference power is... If the threshold is exceeded, the process proceeds to the detailed risk analysis stage.

[0051] S2: Calculation of useful signal power and signal-to-interference ratio S2.1: Determine the useful signal power at each position on the approach track according to the minimum useful signal field strength requirements of ILS specified in GB6364—2013. (Unit: dBm). The minimum signal strength for the heading beacon is 40 μV / m, for the glide slope beacon it is 400 μV / m, and for the marker beacon it is 1.5 mV / m.

[0052] S2.2: Calculate the signal-to-interference ratio at the receiver. Its expression is:

[0053] in, For useful signal power, This represents the interference power.

[0054] S2.3: Based on the frequency deviation between the interference signal and the ILS operating frequency, refer to the ILS protection rate curve specified in ICAO Doc 9718 to determine whether the current interference conditions meet the frequency protection requirements. If the protection rate requirements are met, the impact of the interference on the DDM formation process is deemed acceptable; if the protection rate requirements are not met, proceed to the integrity risk analysis based on the DDM deviation.

[0055] S3: DDM Deviation Calculation S3.1: Under the small interference approximation condition, the effect of interference on the ILS demodulation process is equivalent to the disruption of the balance relationship between the 90 Hz and 150 Hz modulation components, thereby introducing a modulation depth difference shift.

[0056] S3.2: The following model is used to calculate the DDM deviation caused by interference. :

[0057] in, is a proportionality coefficient used to characterize the combined impact of interference regime and receiver characteristics on DDM bias.

[0058] S3.3: In this embodiment, the scaling factor Calibration is performed using standard protection points. For heading beacons, using... The maximum permissible bias caused by dB corresponds to Based on this, it is acceptable. Similarly, for glide slope beacons, the proportional coefficient can be calibrated based on their standard protection points.

[0059] S3.4: This yields the DDM deviation distribution at each position along the aircraft's approach track, which is used to characterize the impact of interference on the accuracy of ILS navigation indication.

[0060] S4: Risk Assessment Based on Operational Level S4.1: Based on the performance requirements for different ILS operating levels in ICAO Annex 10, read the DDM deviation limit or equivalent channel offset limit for the corresponding operating level.

[0061] S4.2: For CAT I operating class, the maximum permissible deviation of the localizer beacon is ±0.015 DDM as the risk assessment limit; for CAT II and CAT III operating classes, the corresponding stricter operating limits are adopted respectively.

[0062] S4.3: Compare the DDM deviation calculated in S3 with the corresponding operating level limit: If the DDM deviation does not exceed the operating level limit, it is judged as a low-risk state, indicating that although the protection rate may have been exceeded, the ILS has not yet suffered an integrity failure. If the DDM deviation exceeds the operating level limit, it is judged as a high-risk state, indicating that the ILS navigation indication contains dangerous and misleading information.

[0063] S4.4: If the interference power does not exceed the maximum allowable interference threshold during the first-level risk screening stage, and the signal-to-interference ratio meets the protection rate requirements, then it is directly determined to be a risk-free state.

[0064] S5: Output risk quantification results The system outputs the final risk level distribution of ILS at various locations along the aircraft's approach track, including three categories: no risk, low risk, and high risk, and provides the corresponding DDM deviation, signal-to-interference ratio, and operational level determination results. This completes the quantitative assessment of ILS disturbance risk.

[0065] Example 2: Quantitative Assessment of VOR Disturbance Risk This embodiment uses an omnidirectional beacon receiver (VOR) as an example to quantitatively assess the azimuth measurement risk under the action of radio countermeasures equipment, specifically as follows: Figure 4 As shown.

[0066] S0: Experimental subjects and general parameter settings A VOR receiver was selected as the target of interference, with an operating frequency band of 108–117.975 MHz, a reference bandwidth of 20 kHz, and a maximum permissible interference power threshold of [missing value]. 88 dBm.

[0067] Input the center frequency, bandwidth, transmit power, transmit antenna gain, and propagation path loss model parameters of the radio countermeasures equipment to construct the interference scenario of the VOR receiver during the aircraft's movement along the flight path.

[0068] S1: Receiver Interference Power Calculation and First-Level Threshold Determination S1.1: Based on the parameters of the radio countermeasures equipment and the propagation model, calculate the interference power received by the VOR receiver at various locations along the aircraft's trajectory. .

[0069] S1.2: Compare the interference power with the maximum permissible interference power threshold of the VOR receiver. Compare at 88 dBm. If dBm, then it is determined that the VOR receiver has no significant risk of interference; if If the value is dBm, it is considered to pose a potential navigational threat and proceeds to the second-level accuracy degradation risk analysis.

[0070] S2: Calculation of useful signal power and signal-to-interference ratio S2.1: Determine the useful signal power at the corresponding location based on the VOR receiver coverage area and the minimum available receive signal condition. .

[0071] S2.2: Calculate the signal-to-interference ratio at the receiver. .

[0072] S2.3: The signal-to-interference ratio is used as the fundamental quantity to characterize the impact of external interference on the performance of VOR phase measurement.

[0073] S3: Azimuth error calculation based on signal-to-interference ratio S3.1: The VOR receiver determines the aircraft's azimuth relative to the station by comparing the phase difference between two 30 Hz signals. External interference will cause random jitter and phase noise in the phase detector output, thus resulting in azimuth error.

[0074] S3.2: Under the strong signal approximation condition, an azimuth error model based on the signal-to-interference ratio is adopted:

[0075] in, This represents the standard deviation of the azimuth error. This is the proportionality coefficient.

[0076] S3.3: Proportional coefficient Calibration is performed based on standard protection points. According to current standards, in... Under dB conditions, the VOR azimuth measurement error should not exceed approximately 0.5°, from which the aforementioned scaling factor can be derived.

[0077] S4: Risk Level Determination S4.1: Read the upper limit of the allowable azimuth error specified by the VOR receiver, for example, ±2°.

[0078] S4.2: Compare the azimuth error calculated in S3 with the allowable upper limit: If the azimuth error does not exceed the allowable upper limit, it is judged as a low-risk state, indicating that although the VOR receiver is affected by interference, it can still maintain basic navigation functions. If the azimuth error exceeds the allowable upper limit, it is judged as a high-risk state, indicating that the navigation accuracy of the VOR receiver can no longer meet the operational requirements.

[0079] S4.3: If the interference power does not exceed the maximum permissible interference power threshold in the first-level threshold determination, it is determined to be a risk-free state.

[0080] S5: Output Results Output the estimated azimuth error of VOR at each location and the corresponding risk level to complete the quantitative assessment of VOR disturbance risk.

[0081] Example 3: Quantitative Assessment of DME Disturbance Risk This embodiment uses a distance measuring instrument (DME) as the object to quantitatively assess the risk of ranging function under interference from radio countermeasures equipment, specifically as follows: Figure 5 As shown.

[0082] Step S0: Experimental subjects and general parameter settings A DME receiver was selected as the target of interference, with an operating frequency band of 960–1215 MHz, a reference bandwidth of 500 kHz, and a maximum permissible interference power threshold of [missing information]. 58 dBm.

[0083] Input the parameters of the radio countermeasures equipment and the propagation path loss model parameters to establish the interference analysis scenario of the DME receiver on the aircraft track.

[0084] S1: Receiver Interference Power Calculation and First-Level Threshold Determination S1.1: Based on the countermeasure device's transmit power, antenna gain, and propagation model, calculate the interference power received by the DME receiver at each location. .

[0085] S1.2: The interference power With the maximum permissible interference power threshold Compare at 58 dBm. If dBm, then it is determined to be a risk-free state; if If dBm is reached, then the process enters the detailed risk analysis stage based on ranging error.

[0086] S2: Calculation of useful signal power and signal-to-interference ratio S2.1: Determine the useful signal power based on the DME coverage area and minimum available received signal requirements. .

[0087] S2.2: Calculate the signal-to-interference ratio .

[0088] S2.3: Use the signal-to-interference ratio as the input parameter for subsequent ranging error estimation.

[0089] S3: Ranging error calculation based on signal-to-interference ratio S3.1: The DME receiver achieves ranging by measuring the round-trip time between the airborne interrogation pulse and the ground response pulse. External interference reduces the signal-to-interference ratio, causing unstable pulse leading edge detection and introducing time jitter.

[0090] S3.2: A ranging error model based on the signal-to-interference ratio is adopted:

[0091] in, This represents the standard deviation of the ranging error.

[0092] S3.3: By combining the pulse waveform, detection threshold, and system reference bandwidth parameters, the proportional constant is calibrated to obtain the estimated distance measurement error at each location.

[0093] S4: Risk Level Determination S4.1: Read the maximum allowable ranging error of the DME during the corresponding operating phase, for example, 370 m.

[0094] S4.2: Compare the ranging error obtained in S3 with the allowable upper limit: If the ranging error does not exceed the allowable upper limit, it is judged as a low-risk state; If the ranging error exceeds the allowable upper limit, it is judged as a high-risk state.

[0095] S4.3: If the interference power does not exceed the maximum allowable interference power threshold during the first-level threshold screening, it is determined to be a risk-free state.

[0096] S5: Output Results Output the ranging error and corresponding risk level of the DME receiver at each location to complete the quantitative assessment of the navigation disturbance risk of the DME receiver.

[0097] Example 4: Quantitative Assessment of GNSS / GBAS Navigation Disturbance Risk This embodiment uses a GNSS (Global Navigation Satellite System), a GBAS (Global Ground Reference Receiver), and a GBAS ground reference receiver as examples to verify the risk quantification capability of this invention for high-precision navigation equipment. Specifically, as follows... Figure 6 As shown.

[0098] S0: Experimental subjects and parameter settings Select GNSS and GBAS as the targets of interference, and read their maximum allowable interference power thresholds under different frequency bands and bandwidth conditions. For example, the threshold for GNSS narrowband receivers is... 124 dBm 133.0 dBm or 134 dBm, GBAS high-precision receiver threshold is 127.4 dBm, etc.

[0099] Input the parameters of the radio countermeasures equipment, the propagation model parameters, and the receiver's operating frequency band information.

[0100] S1: Receiver Interference Power Calculation and First-Level Threshold Determination S1.1: Based on the parameters of the radio countermeasures equipment and the propagation path loss model, calculate the interference power of the GNSS / GBAS receiver in the corresponding frequency band. .

[0101] S1.2: Compare the interference power with the maximum permissible interference power threshold for the corresponding device and frequency band. If If the threshold is not exceeded, the state is considered risk-free; if If the threshold is exceeded, the process proceeds to the safety margin classification analysis stage.

[0102] S2: Risk classification based on safety margin S2.1: Under the premise that the first-level threshold determines that there is a potential risk of flight disruption, a 6 dB safety margin is introduced as the basis for risk classification.

[0103] S2.2: Calculate the amount by which the interference power exceeds the maximum permissible interference power threshold. .

[0104] S2.3: If If dB, it is determined to be a low-risk state, indicating that the system is still near the safety margin boundary; if If the value reaches dB, it is considered a high-risk state, indicating that the system's safety margin has been significantly compromised and there is a significant risk of degradation in positioning accuracy, continuity, or integrity.

[0105] S3: Output Results Output the disturbance power and corresponding risk level of GNSS / GBAS at each analysis location to complete the quantitative assessment of GNSS / GBAS navigation disturbance risk.

[0106] Example 5: Quantitative Assessment of Air Interference Risk for VHF / HF Communication Systems This embodiment uses VHF and HF communication systems as examples to quantitatively assess the communication risks under the interference of radio countermeasures equipment, specifically as follows: Figure 7 As shown.

[0107] S0: Experimental subjects and parameter settings VHF and HF communication systems were selected as the targets of interference. For VHF communication, FM and AM modulation schemes were considered separately. For HF communication, its corresponding operating frequency band, reference bandwidth, MH standard engineering protection signal-to-interference ratio threshold, and ICAO communication performance signal-to-interference ratio threshold were read.

[0108] Input the parameters of the radio countermeasures equipment and the propagation path loss model parameters to establish a scenario where the communication receiver is interfered with.

[0109] S1: Calculation of useful signal power and interference power S1.1: Determine the useful signal power at the communication receiver based on the minimum available received signal strength or the protection signal field strength of the communication system. .

[0110] S1.2: Calculate the interference power at the communication receiver based on the parameters of the radio countermeasures equipment and the propagation model. .

[0111] S1.3: Calculate the signal-to-interference ratio (SIR) at the communication receiver:

[0112] S2: Dual Threshold Risk Assessment S2.1: Compare the signal-to-interference ratio (SIR) with the MH standard engineering protection SIR threshold. If the actual SIR is not lower than the MH threshold, it is determined to be a risk-free state.

[0113] S2.2: If the signal-to-interference ratio is lower than the MH threshold, it is further compared with the ICAO communication performance signal-to-interference ratio threshold.

[0114] S2.3: If the signal-to-interference ratio is lower than the MH threshold but still higher than the ICAO threshold, it is judged as a low-risk state, indicating that the communication link can still maintain basic availability, but the communication quality has degraded; if the actual signal-to-interference ratio is lower than the ICAO threshold, it is judged as a high-risk state, indicating that the communication system can no longer meet the basic communication performance requirements.

[0115] S2.4: For VHF FM, VHF AM and HF communication systems, the above determination shall be made using the corresponding MH and ICAO threshold parameters, respectively.

[0116] S3: Output Results Output the signal-to-interference ratio and risk level of each communication system under different locations or operating conditions, and complete the quantitative assessment of the navigation interference risk of VHF / HF communication systems.

[0117] Example 6: Quantitative assessment of navigational disturbance risks from surveillance equipment such as ADS-B, SSR, and TCAS This embodiment focuses on surveillance radio equipment such as ADS-B ground stations, ground-based secondary radars, airborne secondary radar receivers, TCAS receivers, and TCAS transponders. It quantitatively assesses the surveillance function risks posed by radio countermeasure equipment. Specifically, as follows... Figure 7 As shown.

[0118] S0: Experimental subjects and parameter settings Select surveillance equipment such as ADS-B ground stations, secondary radars, and TCAS as targets for jamming, and read their maximum permissible jamming power thresholds. For example, the maximum permissible jamming power for an ADS-B ground station is... 95 dBm, the maximum permissible interference power of the airborne secondary radar receiver is 81 dBm, the maximum permissible interference power of the TCAS receiver is 95 dBm.

[0119] Input the transmit power, center frequency, bandwidth, antenna gain, and propagation model parameters of the radio countermeasures device.

[0120] S1: Receiver Interference Power Calculation and First-Level Threshold Determination S1.1: Calculate the interference power at the receiver of surveillance equipment based on the parameters of the radio countermeasures device and the propagation path loss model. .

[0121] S1.2: Compare the interference power with the maximum permissible interference power threshold of the corresponding device. If If the threshold is not exceeded, the state is considered risk-free; if If the threshold is exceeded, the pulse detection integrity analysis stage will begin.

[0122] S2: Signal-to-Interference Ratio Integrity Analysis S2.1: Determine the useful signal power based on the minimum available received signal strength of the equipment or the coverage area conditions. .

[0123] S2.2: Calculate the signal-to-interference ratio .

[0124] S2.3: Since monitoring equipment such as ADS-B, SSR, and TCAS all rely on the reliable reception, timing, and information interpretation of pulse signals, the impact of external interference is equivalent to a decrease in the reliability of pulse detection and a deterioration in the stability of timing determination.

[0125] S2.4: If the signal-to-interference ratio (SINR) decreases but pulse detectability can still be maintained, it is judged as a low-risk state; if the SINR decreases to the point that reliable pulse detection and stable decision-making cannot be guaranteed, it is judged as a high-risk state.

[0126] S3: Output Results Output the final risk level of surveillance equipment such as ADS-B, SSR, and TCAS in the analysis scenario, and complete the quantitative assessment of the navigation disturbance risk of surveillance equipment.

[0127] Example 7: Comprehensive Flight Interference Risk Assessment for Multiple Types of Aviation Radio Equipment In a preferred embodiment, a comprehensive air traffic interference risk assessment can be conducted simultaneously on multiple types of aviation radio equipment operating in the same scenario. Specifically: First, following the methods of Examples 1 to 6, calculate the single-device risk level of navigation, communication, and surveillance devices under the same interference scenario; Secondly, the risk results for each piece of equipment are comprehensively evaluated based on equipment importance, sensitivity of the operational phase, or safety weight. Finally, the overall risk assessment of air traffic disruption in the output scenario is provided to support the evaluation of radio countermeasures equipment deployment, airport electromagnetic environment safety analysis, and flight operation risk warning.

[0128] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0129] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0130] In this invention, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0131] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A risk assessment method for aviation radio equipment that interferes with flight operations using radio countermeasures devices, characterized in that, Includes the following steps: Step S0: Obtain the type and parameters of the jammed aviation radio equipment, wherein the types of aviation radio equipment include navigation, communication and surveillance. Step S1: Set the parameters of the radio countermeasures device and determine the type of interference; Step S2: Calculate the interference power of the receiver of the interfered aviation radio equipment according to the type of aviation radio equipment and the type of interference; Step S3: Based on the interference power, perform a level-one risk assessment. If a level-one risk exists, proceed to step S4. Otherwise, if no risk is identified, proceed to step S5; Step S4: Based on the type of aviation radio equipment, conduct a secondary risk assessment to obtain the final air traffic disturbance risk assessment result; Step S5: Output the flight disturbance risk assessment results for aviation radio equipment.

2. The risk assessment method for aviation radio equipment interference caused by radio countermeasures equipment according to claim 1, characterized in that, In step S0 Navigation systems include Instrument Landing Systems (ILS), VOR (Voyager Orbit), Distance Measuring Instruments (DME), Global Navigation Satellite Systems (GNSS), and Ground-Based Augmentation Systems (GBAS). Communication categories include Very High Frequency (VHF) communication and High Frequency (HF) communication. Surveillance systems include Automatic Dependent Surveillance-Broadcast (ADS-B), Secondary Surveillance Radar (SSR), Multipoint Positioning System (MLAT), and Tele-Cross-Air Collision Avoidance System (TCAS). The parameters of aviation radio equipment include operating frequency band, reference bandwidth, maximum permissible interference power threshold, protection ratio threshold, operating accuracy limit, and operating class.

3. The risk assessment method for aviation radio equipment interference caused by radio countermeasures equipment according to claim 2, characterized in that, Step S1 specifically includes: Step S1-1: Set the parameters of the radio countermeasure equipment, including center frequency, bandwidth, transmit power, antenna gain and modulation scheme; Step S1-2: Based on the frequency difference between the center frequency of the radio countermeasure equipment and the operating frequency band of the interfered aviation radio equipment, determine the type of interference as co-channel interference, adjacent channel interference, blocking interference, broadband interference, harmonic interference, or intermodulation interference.

4. The aviation radio equipment risk assessment method for interference with flight operations by radio countermeasures equipment as described in claim 3, characterized in that, Step S2 specifically includes: For co-channel interference, adjacent channel interference, blocking interference, and harmonic interference, the interference power at the receiver of the aviation radio equipment is calculated based on the aforementioned transmit power, antenna gain, and propagation path loss model. I ; For broadband interference, the equivalent interference power within the reference bandwidth of the aviation radio equipment receiver is calculated as the interference power. I ; For intermodulation interference, a third-order intermodulation model is used to calculate the power of the intermodulation products and convert it into the interference power at the receiver of the aviation radio equipment. I .

5. The risk assessment method for aviation radio equipment interference caused by radio countermeasures equipment according to claim 4, characterized in that, Step S3 specifically includes: Determine whether the interference power is greater than the maximum permissible interference power threshold of the aviation radio equipment. If so, determine that there is a level 1 risk and proceed to step S4; otherwise, determine that there is no risk and proceed to step S5.

6. The risk assessment method for aviation radio equipment interference caused by radio countermeasures equipment according to claim 5, characterized in that, In step S4, the secondary risk assessment process for ILS is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) Calculate the DDM deviation based on the risk quantification model of the DDM deviation; (3) Determine whether the DDM deviation is within the operating level limit. If it is, it is determined to be low risk; otherwise, it is determined to be high risk.

7. The risk assessment method for aviation radio equipment interference caused by radio countermeasures equipment according to claim 5, characterized in that, In step S4, the secondary risk assessment process for VOR is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) Calculate the azimuth error based on the risk quantification model of azimuth error; (3) Determine whether the azimuth error exceeds the allowable upper limit. If so, it is determined to be high risk. Otherwise, it is judged as low risk.

8. The aviation radio equipment risk assessment method for interference with flight operations by radio countermeasures equipment as described in claim 5, characterized in that, In step S4, the secondary risk assessment process for DME is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) Calculate the ranging error based on the risk quantification model of ranging error; (3) Determine whether the ranging error exceeds the allowable upper limit. If so, it is determined to be high risk; otherwise, it is determined to be low risk. The process for assessing secondary risks for GNSS and GBAS is as follows: (1) Calculate the amount by which the interference power exceeds the maximum permissible interference power threshold; (2) Determine whether the excess amount exceeds the safety margin specified in the standard. If so, it is determined to be high risk; otherwise, it is determined to be low risk.

9. The aviation radio equipment risk assessment method for interference with flight operations by radio countermeasures equipment as described in claim 8, characterized in that, In step S4, the secondary risk assessment process for communication-related aviation radio equipment is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) Determine whether the signal-to-interference ratio is not lower than the MH threshold. If it is, then it is determined to be risk-free. If not, then determine whether the signal-to-interference ratio is higher than the ICAO threshold. If it is, then it is determined to be low risk. Otherwise, it is determined to be high risk.

10. The aviation radio equipment risk assessment method for interference with flight operations by radio countermeasures equipment according to claim 9, characterized in that, The secondary risk assessment process for surveillance-type aviation radio equipment is as follows: (1) Calculate the signal-to-interference ratio based on the minimum useful signal field strength or minimum available received signal strength and interference power specified in the standard; (2) If the signal-to-interference ratio can maintain pulse detectability, it is judged as low risk; otherwise, it is judged as high risk.

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