Anti-spoofing detection method, data processing method and flight management system

Abstract

The application provides an anti-fraud detection method, a data processing method and a flight management system. The method comprises the following steps: selecting a navigation source as a first navigation source and selecting another navigation source as a second navigation source from a plurality of preset navigation sources; acquiring navigation data of the plurality of preset navigation sources and performing fraud detection calculation on the first navigation source by using the navigation data; determining whether the first navigation source is fraudulent according to a result of the fraud detection calculation, and performing fraud detection calculation on the second navigation source by using the navigation data except the first navigation source in the case that the first navigation source is determined to be fraudulent. The application performs fraud detection on the navigation data of the first navigation source by using the navigation data of the second navigation source and other navigation sources, so that the detection accuracy is higher, and pseudo-range level fraud interference detection on the first navigation source can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite data processing, and particularly relates to an anti-spoofing detection method, a data processing method and a flight management system. BACKGROUND

[0002] The flight management system (FMS) is an airborne avionics system which assists the pilot to complete various tasks from take-off to landing, can manage, monitor and automatically control the aircraft, and realizes automatic flight of the aircraft throughout the entire flight.

[0003] At present, the FMS of a civil aircraft generally only supports navigation positioning function based on the global positioning system (GPS) as a single global navigation satellite system (GNSS) source, and does not have the anti-GNSS spoofing interference function. Once the GPS is interfered, the positioning accuracy of the aircraft will be greatly reduced, the operation burden and pressure of the pilot will be significantly increased, and even the abnormal flight guiding function may be caused due to the wrong navigation positioning, the aircraft will make unexpected maneuvers, and the flight safety will be affected. SUMMARY

[0004] The present application provides an anti-spoofing detection method, a data processing method and a flight management system, to solve the problem that the flight management system of the prior art does not have the anti-GNSS spoofing interference function.

[0005] In a first aspect, the present application provides an anti-spoofing detection method, which comprises:

[0006] selecting a navigation source as a first navigation source and another navigation source as a second navigation source from a plurality of preset navigation sources;

[0007] obtaining navigation data of the plurality of preset navigation sources and performing spoofing detection calculation on the first navigation source by using the navigation data;

[0008] determining whether the first navigation source is spoofed according to the result of the spoofing detection calculation, and performing spoofing detection calculation on the second navigation source by using the navigation data except the first navigation source in the case that the first navigation source is determined to be spoofed.

[0009] In an embodiment of the present application, the step of performing spoofing detection calculation on the first navigation source by using the navigation data comprises:

[0010] selecting a third navigation source and a fourth navigation source from the plurality of preset navigation sources;

[0011] calculating pseudo-range estimation values of the first navigation source and the second navigation source according to the navigation data of the third navigation source, and calculating an equivalent pseudo-range of the fourth navigation source according to the navigation data of the third navigation source and the fourth navigation source;

[0012] According to the pseudo-range estimation values of the first navigation source and the second navigation source and the equivalent pseudo-range of the fourth navigation source, a spoofing detection quantity and a spoofing detection statistic of each visible star in the first navigation source are calculated.

[0013] In an embodiment of the present application, the step of calculating the spoofing detection quantity and the spoofing detection statistic of each visible star in the first navigation source according to the pseudo-range estimation values of the first navigation source and the second navigation source and the equivalent pseudo-range of the fourth navigation source comprises:

[0014] The pseudo-range of the first navigation source and the pseudo-range of the second navigation source are subtracted from the corresponding pseudo-range estimation values, and the slant range of the fourth navigation source is subtracted from the equivalent pseudo-range, to construct a first measurement equation;

[0015] According to the constructed first measurement equation, the spoofing detection quantity of each visible star in the first navigation source is calculated.

[0016] In an embodiment of the present application, the step of calculating the spoofing detection quantity and the spoofing detection statistic of each visible star in the first navigation source according to the pseudo-range estimation values of the first navigation source and the second navigation source and the equivalent pseudo-range of the fourth navigation source further comprises:

[0017] According to the spoofing detection quantity of each visible star in the first navigation source, a first spoofing detection statistic corresponding to the visible star is calculated;

[0018] The first spoofing detection statistic is compared with a first preset spoofing detection threshold value;

[0019] If the first spoofing detection statistic exceeds the first preset spoofing detection threshold value, it is determined that the signal of the visible star of the first navigation source is spoofed.

[0020] All visible stars of the first navigation source are traversed to determine whether each visible star is spoofed, and a detection result of the first navigation source is output.

[0021] In an embodiment of the present application, if at least one visible star signal of the first navigation source is spoofed, it is determined that the first navigation source is spoofed.

[0022] In an embodiment of the present application, the step of performing spoofing detection calculation on the second navigation source by using the navigation data other than the first navigation source comprises:

[0023] The pseudo-range estimation value of the second navigation source is calculated according to the navigation data of the third navigation source, and the equivalent pseudo-range of the fourth navigation source is calculated according to the navigation data of the third navigation source and the fourth navigation source;

[0024] The spoofing detection quantity and the spoofing detection statistic of each visible star in the second navigation source are calculated according to the pseudo-range estimation value of the second navigation source and the equivalent pseudo-range of the fourth navigation source.

[0025] In an embodiment of the present application, the step of calculating the spoofing detection quantity and the spoofing detection statistic of each visible star in the second navigation source according to the pseudo-range estimation value of the second navigation source and the equivalent pseudo-range of the fourth navigation source comprises:

[0026] The pseudo-range of the second navigation source is subtracted from the pseudo-range estimation value thereof, and the slant range of the fourth navigation source is subtracted from the equivalent pseudo-range thereof, to construct a second measurement equation;

[0027] The spoofing detection quantity of each visible star in the second navigation source is calculated according to the constructed second measurement equation.

[0028] In an embodiment of the present application, the step of calculating the spoofing detection quantity and the spoofing detection statistic of each visible star in the second navigation source according to the pseudo-range estimation value of the second navigation source and the equivalent pseudo-range of the fourth navigation source further comprises:

[0029] The second spoofing detection statistic corresponding to each visible star in the second navigation source is calculated according to the spoofing detection quantity of the visible star;

[0030] The size of the second spoofing detection statistic is compared with that of a second preset spoofing detection threshold;

[0031] If the second spoofing detection statistic exceeds the second preset spoofing detection threshold, it is determined that the signal of the visible star in the second navigation source is spoofed;

[0032] All visible stars in the second navigation source are traversed to determine whether each visible star is spoofed, and the detection result of the second navigation source is output.

[0033] In a second aspect, the present application further provides a data processing method, which comprises:

[0034] According to the detection result of any one of the first aspect, a navigation mode is generated and the navigation position of the aircraft is calculated according to the navigation mode;

[0035] The navigation mode includes an automatic mode, a first mode to a fourth mode, the first mode is a mode of fusing a first navigation source and other navigation sources except a second navigation source, the second mode is a mode of fusing the second navigation source and other navigation sources except the first navigation source, the third mode is a mode of fusing a visible star in the first navigation source and the second navigation source which is not cheated and other navigation sources, and the fourth mode is a mode of fusing a third navigation source and other navigation sources except the first navigation source and the second navigation source.

[0036] In an embodiment of the present application, the step of calculating the navigation position of the aircraft according to the navigation mode includes:

[0037] If the detection result is that the first navigation source and the second navigation source are not cheated, the first mode is used to calculate the navigation position of the aircraft.

[0038] If the detection result is that the first navigation source is cheated and the second navigation source is not cheated, the second mode is used to calculate the navigation position of the aircraft.

[0039] If the detection result is that the first navigation source and the second navigation source are cheated and there is a visible star which can be used and is not cheated, the third mode is used to calculate the navigation position of the aircraft.

[0040] If the detection result is that the first navigation source and the second navigation source are cheated and there is no visible star which can be used, the fourth mode is used to calculate the navigation position of the aircraft.

[0041] In an embodiment of the present application, the method further includes:

[0042] Displaying the navigation mode on a preset interface for the pilot to select.

[0043] Responding to the navigation mode corresponding to the execution instruction of the pilot after receiving the instruction.

[0044] In an embodiment of the present application, the step of displaying the navigation mode on a preset interface for the pilot to select includes:

[0045] In the automatic mode, the navigation source and the corresponding navigation performance and whether it is effective selected by the flight management system are displayed.

[0046] In an embodiment of the present application, the step of displaying the navigation mode for the pilot to select includes:

[0047] In the first mode, the flight management system displays in its corresponding first column the current navigation sources fused with other navigation sources except the second navigation source, displays in its corresponding second column the corresponding navigation performance, and displays in its corresponding third column whether the first mode is valid. If the detection result is that the first navigation source is spoofed, the flight management system displays in the third column that the first mode is invalid and issues an alert.

[0048] In one embodiment of the present application, the step of displaying the navigation modes for the pilot to select comprises:

[0049] In the second mode, the flight management system prioritizes the second navigation source fused with other navigation sources except the first navigation source, displays in its corresponding first column the current fused navigation sources, displays in its corresponding second column the corresponding navigation performance, and displays in its corresponding third column whether the second mode is valid. If the detection result is that the second navigation source is spoofed, the flight management system displays in the third column that the second mode is invalid and issues an alert.

[0050] In one embodiment of the present application, the step of displaying the navigation modes for the pilot to select comprises:

[0051] In the third mode, the flight management system selects the first navigation source and the second navigation source fused with other navigation sources that are not spoofed and can be used, displays in its corresponding first column the current fused navigation sources, displays in its corresponding second column the corresponding navigation performance, and displays in its corresponding third column whether the third mode is valid. If the detection result is that both the first navigation source and the second navigation source are spoofed and there is no visible star that can be used, the flight management system displays in the third column that the third mode is invalid and issues an alert.

[0052] In one embodiment of the present application, the step of displaying the navigation modes for the pilot to select comprises:

[0053] In the fourth mode, the flight management system selects the third navigation source fused with other navigation sources except the first navigation source and the second navigation source, displays in its corresponding first column the current fused navigation sources, displays in its corresponding second column the corresponding navigation performance, and displays in its corresponding third column whether the fourth mode is valid.

[0054] In a third aspect, the present application also provides a flight management system, which comprises:

[0055] anti-spoofing detection means for performing the anti-spoofing detection method of any one of the first aspect;

[0056] A data processing device for performing the data processing method of any one of the second aspect.

[0057] In an embodiment of the present application, the first navigation source and the second navigation source are any one of GPS, BDS, GLONASS and GALILEO navigation sources, the third navigation source is an IRS navigation source, and the fourth navigation source is a DME navigation source.

[0058] The anti-spoofing detection method, the data processing method and the flight management system provided by the present application can detect whether the first navigation source is spoofed by selecting the first navigation source and the second navigation source from a plurality of preset navigation sources for navigation, and performing spoofing detection calculation on the first navigation source by using the second navigation source and other navigation sources. In addition, the spoofing detection calculation is performed on the second navigation source in the case that the first navigation source is spoofed. The spoofing detection accuracy is higher because the navigation data of the second navigation source and other navigation sources are used to perform spoofing detection on the navigation data of the first navigation source. The pseudo-range level spoofing interference detection of the first navigation source can be realized. In addition, the spoofing detection calculation is performed on the second navigation source in the case that the first navigation source is spoofed, and the reliability is higher. BRIEF DESCRIPTION OF DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0060] Figure 1 is a flowchart of the anti-spoofing detection method provided by the present application;

[0061] Figure 2 is a flowchart of the detection of the first navigation source provided by the present application;

[0062] Figure 3 is a flowchart of the detection of the second navigation source provided by the present application;

[0063] Figure 4 is a flowchart of the data processing method provided by the present application;

[0064] Figure 5 is an interface diagram of the navigation mode provided by the present application;

[0065] Figure 6 is an architecture diagram of the flight management system provided by the embodiment of the present application. DETAILED DESCRIPTION

[0066] In order to make the objects, technical solutions and advantages of the present application clearer, the accompanying drawings will be briefly described and the technical solutions will be clearly and completely described in the present application with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0067] The terms "first", "second", and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0068] The following describes the technical terms related to the present application:

[0069] GNSS: Global navigation satellite system (Global navigation satellite system), refers to all satellite navigation systems, including global, regional and enhanced, such as China's Beidou satellite navigation system (BDS), the United States Global Positioning System (GPS), Russia's GLONASS satellite navigation system (GLONASS) and the European Union's Galileo satellite navigation system (GALILEO).

[0070] DME: Distance Measure Equipment, a radio navigation device signal generator used by an aircraft, installed on the airport and the air route, is the main air route navigation equipment. The aircraft uses DME to measure the distance between itself and the ground transmitter by transmitting and receiving a pair of fixed interval pulse signals.

[0071] IRS: Inertial Reference System, an autonomous navigation system independent of external information, which uses Newton's classical mechanics to calculate the aircraft's position, speed, heading and other information through sensor data.

[0072] To address the lack of anti-GNSS spoofing interference capabilities in existing flight management systems, this invention provides an anti-spoofing detection method, a data processing method, and a flight management system. The method involves selecting a first navigation source and a second navigation source from multiple preset navigation sources for navigation, and using the second navigation source and other navigation sources to perform spoofing detection calculations on the first navigation source to detect whether it has been spoofed. If the first navigation source has been spoofed, spoofing detection calculations are then performed on the second navigation source. Because this invention uses navigation data from the second navigation source and other navigation sources to perform spoofing detection on the navigation data of the first navigation source, its detection accuracy is higher, enabling pseudorange-level spoofing interference detection on the first navigation source. Furthermore, since spoofing calculations are performed on the second navigation source even when the first navigation source has been spoofed, its reliability is higher.

[0073] The following fusion Figures 1-6 The present invention describes the anti-spoofing detection method, data processing method, and flight management system.

[0074] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating the anti-spoofing detection method provided by the present invention. An anti-spoofing detection method, the method comprising:

[0075] Step 110: Select one navigation source from multiple preset navigation sources as the first navigation source and select another navigation source as the second navigation source.

[0076] For example, the plurality of preset navigation sources include existing GNSS navigation sources such as GPS, BDS, GLONASS, and GALILEO, as well as new GNSS navigation sources that may be established in the future. The first and second navigation sources can be any one of the GNSS navigation sources such as GPS, BDS, GLONASS, and GALILEO. For example, the first navigation source could be GPS, and the second navigation source could be BDS. Of course, other navigation sources can also be selected, and this invention does not limit this choice.

[0077] Step 120: Obtain navigation data from the multiple preset navigation sources and use the navigation data to perform deception detection calculation on the first navigation source.

[0078] Step 130: Determine whether the first navigation source has been deceived based on the result of the deception detection calculation, and if the first navigation source has been deceived, perform deception detection calculation on the second navigation source using navigation data other than the first navigation source.

[0079] The following is a detailed description of steps 110 to 130 above.

[0080] Please refer to Figure 2 , Figure 2This is a schematic diagram of the process for detecting a first navigation source provided by the present invention. In step 120 above, the step of using the navigation data to perform deception detection calculations on the first navigation source includes:

[0081] Step 210: Select the third and fourth navigation sources from multiple preset navigation sources.

[0082] For example, multiple preset navigation sources include GPS, BDS, DME, and IRS, etc. Suppose that the first navigation source is GPS, the second navigation source is BDS, the third navigation source is IRS, and the fourth navigation source is DME.

[0083] Step 220: Calculate the pseudorange estimates of the first and second navigation sources based on the navigation data of the third navigation source, and calculate the equivalent pseudorange of the fourth navigation source based on the navigation data of the third and fourth navigation sources.

[0084] For example, the ways to obtain navigation data from GPS, BDS, DME, and IRS are as follows:

[0085] The GNSS receiver on the aircraft can receive GPS navigation signals and BDS navigation signals from GPS satellites and BDS satellites, the DME receiver on the aircraft can receive DME navigation signals from DME navigation stations, and the IRS on the aircraft can autonomously calculate navigation information.

[0086] The GNSS receiver receives GPS and BDS information, including: pseudorange and GPS satellite position for each visible GPS satellite, pseudorange and BDS satellite position for each visible BDS satellite. The pseudorange is the distance from the GNSS receiver to the visible satellite calculated by the GNSS receiver based on the navigation signal, and the satellite position is obtained by the GNSS receiver based on the satellite ephemeris in the navigation signal.

[0087] The DME receiver receives DME information, including DME slant range and DME navigation station position. The DME slant range is the distance from the DME receiver on the aircraft to the DME navigation station, calculated by the DME receiver based on the DME navigation signal.

[0088] Among them, the aircraft position is received from the IRS.

[0089] For example, pseudorange estimates for GPS and BDS satellites can be calculated using IRS location and ephemeris information, and DME equivalent pseudoranges can be calculated using IRS location and DME navigation station location, as detailed below:

[0090] GPS satellite pseudorange estimates are the Euclidean distances between the aircraft position received from the IRS and the GPS satellite position received from the GNSS receiver in the WGS-84 coordinate system. BDS satellite pseudorange estimates are the Euclidean distances between the aircraft position received from the IRS and the BDS satellite position received from the GNSS receiver in the WGS-84 coordinate system. DME equivalent pseudorange is the Euclidean distance between the aircraft position received from the IRS and the DME navigation station position in the WGS-84 coordinate system.

[0091] Step 230: Based on the pseudorange estimates of the first and second navigation sources and the equivalent pseudorange of the fourth navigation source, calculate the deception detection quantity and deception detection statistics for each visible star in the first navigation source.

[0092] For example, the steps for calculating the deception detection quantity include:

[0093] Step 231: Subtract the pseudoranges of the first and second navigation sources from their corresponding pseudorange estimates, and subtract the slant range of the fourth navigation source from its equivalent pseudorange, to construct the first measurement equation.

[0094] For example, the calculation method for GPS visible satellite spoofing detection is as follows:

[0095] (a) After Taylor expansion of the above GPS satellite pseudorange estimates, BDS satellite pseudorange estimates and DME equivalent pseudorange, retain the first-order error.

[0096] (b) The first measurement equation is constructed by subtracting the pseudorange estimates of GPS satellites, BDS satellites, and DME equivalent pseudoranges after Taylor expansion from the pseudorange estimates of visible GPS satellites, BDS visible satellites, and DME slant ranges, respectively.

[0097] Step 232: Calculate the deception detection amount of each visible star in the first navigation source based on the constructed first measurement equation.

[0098] For example, based on the measurement measurements in the measurement equation, the spoofing detection quantity of GPS visible satellites can be obtained.

[0099] For example, the steps for calculating the deception detection statistic include:

[0100] Step 233: Calculate the first deception detection statistic corresponding to each visible star based on the deception detection quantity of each visible star of the first navigation source.

[0101] For example, based on the GPS visible satellite spoofing detection rate and the sequential probability ratio detection algorithm, the GPS spoofing detection statistics and the first spoofing detection threshold can be obtained.

[0102] Step 234: Compare the first deception detection statistic with the first preset deception detection threshold.

[0103] Step 235: If the first deception detection statistic exceeds the first preset deception detection threshold, then it is determined that the signal of the visible star of the first navigation source has been deceiving.

[0104] For example, the GPS spoofing detection statistics are compared with a first spoofing detection threshold. If the threshold is exceeded, the GPS visible satellite signal is determined to be spoofed.

[0105] Step 236: Iterate through all visible stars of the first navigation source to determine whether each visible star has been deceived, and output the detection result of the first navigation source.

[0106] If at least one visible star signal of the first navigation source is spoofed, then the first navigation source is determined to be spoofed.

[0107] Therefore, in this embodiment of the invention, the navigation data of multiple navigation sources (e.g., BDS, DME, IRS) are used to perform deception detection on the first navigation source (e.g., GPS), which has higher detection accuracy and can realize pseudorange-level deception interference detection on the first navigation source.

[0108] The above describes the detection method for whether a first navigation source is being spoofed according to the present invention. In some embodiments of the present invention, if it is determined according to step 236 that at least one visible satellite signal of the first navigation source is being spoofed, then it is necessary to continue the spoofing detection calculation for the second navigation source. The detection of the first navigation source can be called outer layer detection, and the detection of the second navigation source can be called inner layer detection. The inner layer detection method is similar to the outer layer detection method, except that the inner layer detection method uses BDS, DME, and IRS information to detect whether the BDS visible satellite is being spoofed, instead of using GPS information.

[0109] Please refer to Figure 3 , Figure 3 This is a schematic flowchart of the detection process for the second navigation source provided by the present invention. In step 236 above, if at least one visible star signal of the first navigation source is spoofed, a spoofing detection calculation is performed on the second navigation source, including:

[0110] Step 310: Calculate the pseudorange estimate of the second navigation source based on the navigation data of the third navigation source, and calculate the equivalent pseudorange of the fourth navigation source based on the navigation data of the third and fourth navigation sources.

[0111] For example, the pseudorange estimate of BDS satellites can be calculated using IRS location and ephemeris information, and the equivalent pseudorange of DME can be calculated using IRS location and DME navigation station location.

[0112] Step 320: Calculate the deception detection quantity and deception detection statistic for each visible star in the second navigation source based on the pseudorange estimate of the second navigation source and the equivalent pseudorange of the fourth navigation source.

[0113] For example, the steps for calculating the deception detection quantity include:

[0114] Step 321: Subtract the pseudorange and pseudorange estimate of the second navigation source, and subtract the slant range and its equivalent pseudorange of the fourth navigation source to construct the second measurement equation.

[0115] For example, the second measurement equation is constructed by subtracting the BDS satellite pseudorange from the BDS pseudorange estimate and subtracting the DME pseudorange from the DME equivalent pseudorange.

[0116] Step 322: Calculate the deception detection amount of each visible star in the second navigation source based on the constructed second measurement equation.

[0117] For example, the steps for calculating the deception detection statistic include:

[0118] Step 323: Calculate the second deception detection statistic corresponding to each visible star based on the deception detection quantity of each visible star of the second navigation source.

[0119] For example, calculate the spoofing detection statistic corresponding to each BDS visible star based on the spoofing detection rate of that BDS visible star.

[0120] Step 324: Compare the second deception detection statistic with the second preset deception detection threshold.

[0121] Step 325: If the second deception detection statistic exceeds the second preset deception detection threshold, then it is determined that the signal of the visible star of the second navigation source has been deceiving.

[0122] For example, if the threshold is exceeded, the BDS visible star signal is determined to be spoofed.

[0123] Step 326: Iterate through all visible stars of the second navigation source to determine whether each visible star has been deceived, and output the detection result of the second navigation source.

[0124] For example, iterate through all BDS visible star signals, detect whether each BDS visible star is being spoofed, and output the BDS detection results.

[0125] Similarly, if at least one visible star signal of the second navigation source is spoofed, then it is determined that the second navigation source has been spoofed.

[0126] Therefore, in this embodiment of the invention, the second navigation source (e.g., BDS) is subjected to pseudorange-level deception detection using navigation data from other navigation sources besides the first navigation source (e.g., DME and IRS) that are not subject to deception interference, resulting in higher reliability.

[0127] In some embodiments of the present invention, after completing the above-described steps of deception detection of the first navigation source and deception detection of the second navigation source, the present invention also provides a data processing method that can provide a corresponding navigation mode for the pilot to select based on the detection results of the first navigation source and the second navigation source.

[0128] Please refer to Figure 4 , Figure 4 This is a flowchart illustrating the data processing method provided by the present invention. A data processing method, the method comprising:

[0129] Step 410: Based on the detection results of the aforementioned anti-spoofing detection method, generate a navigation mode and calculate the navigation position of the aircraft based on the navigation mode.

[0130] The navigation modes include automatic mode, first mode, second mode, third mode, and fourth mode. The first mode is a mode that merges a first navigation source with other navigation sources besides the second navigation source; the second mode is a mode that merges a second navigation source with other navigation sources besides the first navigation source; the third mode is a mode that merges unspoofed visible stars from the first and second navigation sources with other navigation sources; and the fourth mode is a navigation mode that merges a third navigation source with other navigation sources besides the first and second navigation sources.

[0131] For example, step 410 above includes:

[0132] Step 411: If the detection result is that neither the first navigation source nor the second navigation source has been deceived, then the first mode is used to calculate the navigation position of the aircraft.

[0133] Step 412: If the detection result is that the first navigation source is deceived and the second navigation source is not deceived, then the second mode is used to calculate the navigation position of the aircraft.

[0134] Step 413: If the detection result is that both the first and second navigation sources are deceived and there are usable, undeceived visible stars, then the third mode is used to calculate the navigation position of the spacecraft.

[0135] Step 414: If the detection result is that both the first and second navigation sources are deceived and there are no usable visible stars, then the fourth mode is used to calculate the navigation position of the spacecraft.

[0136] It should be noted that the mode selection logic in step 410 above is based on the navigation source selection logic in automatic mode, but the pilot can also manually select any of the first to fourth modes mentioned above.

[0137] In some embodiments of the present invention, the data processing method further includes:

[0138] The above navigation modes are displayed on the preset interface for pilots to select. When the Flight Management System (FMS) receives the pilot's execution command, it responds to the navigation mode corresponding to the command.

[0139] For example, please refer to Figure 5 , Figure 5 This is a schematic diagram of the interface demonstrating the navigation modes provided by the present invention. The navigation system (NAV) interface of the flight management system offers five navigation mode options:

[0140] 1) AUTO: Automatic mode;

[0141] 2) GPS PRIME: GPS primary mode;

[0142] 3) BDS PRIME: BDS primary mode;

[0143] 4) GNSS INTEROP: BDS and GPS interoperability mode;

[0144] 5) IRS / RADIO: IRS / RADIO degradation mode.

[0145] It should be noted that the GPS primary mode described above is an example of the first mode, the BDS primary mode is an example of the second mode, the BDS and GPS interoperability mode is an example of the third mode, and the IRS / RADIO degradation mode is an example of the fourth mode. However, the present invention is not limited to the above modes, and can be designed according to actual needs.

[0146] The navigation source used for the five navigation modes described above (1) through 5) will be given in the first column (e.g., the SOURCE column). Each navigation performance is given in Actual Navigation Performance (ANP) in nautical miles in the second column (e.g., the ANP column). Based on the deception detection results, a green light indicates validity, and a red light indicates invalidity, given in the third column (e.g., the Valid column). Valid navigation modes will be displayed in gray. This information will always be displayed regardless of whether automatic mode is activated, for the pilot's information and reference.

[0147] The default navigation mode is automatic (AUTO), and only one mode can be selected at any given time.

[0148] For example, in automatic mode, the navigation source automatically selected by the flight management system, its corresponding navigation performance, and whether it is effective are displayed.

[0149] For example, in the first mode, the navigation source that is the current first navigation source merged with other navigation sources other than the second navigation source is displayed in the first column, the corresponding navigation performance is displayed in the second column, and whether the first mode is effective is displayed in the third column. If the detection result is that the first navigation source is deceived, the first mode is invalid and an alarm is issued in the third column.

[0150] For example, in GPS primary mode, FMS will prioritize the fusion of GPS with other navigation sources besides BDS, and display the currently fused navigation source in the SOURCE column, always display the corresponding navigation performance in the AN P column, and display whether the GPS primary mode is valid in the Valid column. If GPS spoofing is detected, it will be displayed in gray in the Valid column and an alarm will be issued.

[0151] For example, in the second mode, the flight management system prioritizes the fusion of the second navigation source with other navigation sources besides the first navigation source, displays the currently fused navigation source in its corresponding first column, displays the corresponding navigation performance in its corresponding second column, and displays whether the second mode is effective in its corresponding third column. If the detection result is that the second navigation source is deceived, the second mode is invalid and an alarm is issued in the third column.

[0152] For example, in BDS primary mode, FMS will prioritize the fusion of BDS with other navigation sources besides GPS, and display the currently fused navigation source in the SOURCE column, always display the corresponding navigation performance in the AN P column, and display whether the BDS primary mode is valid in the Valid column. If BDS is detected to be spoofed, it will be displayed in gray in the Valid column and an alarm will be issued.

[0153] For example, in the third mode, the flight management system selects a usable, unspoofed visible star from the first and second navigation sources and merges it with other navigation sources. The merged navigation source is displayed in the first column, the corresponding navigation performance is displayed in the second column, and the validity of the third mode is displayed in the third column. If the detection result is that both the first and second navigation sources are spoofed and there is no usable visible star, the third mode is displayed as invalid in the third column and an alarm is issued.

[0154] For example, in BDS and GPS interoperability mode, FMS will select unspoofed visible satellite signals from BDS and GPS, fuse them with other navigation sources, and display the currently fused navigation sources in the SOURCE column. The corresponding navigation performance will always be displayed in the ANP column, and the Valid column will indicate whether the BDS and GPS interoperability mode is valid; if there are insufficient available BDS and GPS satellites, the Valid column will be grayed out and an alarm will be issued.

[0155] For example, in the fourth mode, the flight management system selects a third navigation source to merge with other navigation sources besides the first and second navigation sources, displays the currently merged navigation source in its corresponding first column, displays the corresponding navigation performance in its corresponding second column, and displays whether the fourth mode is effective in its corresponding third column.

[0156] For example, in IRS / RADIO downgrade mode, FMS will select IRS and merge it with other navigation sources besides GPS and BDS, and display the currently merged navigation source in the SOURCE column, always display the corresponding navigation performance in the ANP column, and display whether the IRS / RADIO downgrade mode is valid in the Valid column.

[0157] It should be noted that after selecting the navigation mode AUTO, GPS PRIME, BDS PRIME, GNSS INTEROP, or IRS / RADIO, the pilot needs to press the execute button (e.g., EXEC) to make the changes take effect.

[0158] Therefore, this invention, based on multi-mode GNSS anti-spoofing detection, also provides a data processing method that offers selection / switching / display functions for the multi-mode GNSS navigation sources involved. This not only solves the problem of whether GNSS navigation sources are spoofed, but also addresses the issues of navigation accuracy and availability of FMS in spoofing environments.

[0159] It should be noted that the anti-spoofing detection method provided by this invention includes a two-layer spoofing interference detection method with inner and outer layer detection. This method can fuse information from other navigation sources and implement a pseudorange-level GNSS spoofing interference detection algorithm. It can eliminate only the spoofed satellite signals without isolating the entire satellite navigation system, thus ensuring the navigation accuracy of FMS in spoofing environments as much as possible. The anti-spoofing detection method is applicable to, for example, FMS navigation computing architectures that use GPS as the primary GNSS navigation source and other satellite navigation systems such as BDS and GLONASS as secondary GNSS navigation sources, resulting in higher reliability.

[0160] Furthermore, the data processing method provided by this invention, based on the above-mentioned two-layer deception interference detection method, provides the navigation mode of FMS for the pilot to select automatically, and also provides the NAV selection interface of FMS with anti-deception function, providing the pilot with a human-machine interaction interface for automatic and manual selection, and also providing reference information to assist in the selection.

[0161] In some embodiments of the present invention, a flight management system is also provided, the system including an anti-spoofing detection device and a data processing device. The anti-spoofing detection device is used to execute the anti-spoofing detection method described in any of the above embodiments. The data processing device is used to execute the data processing method described in any of the above embodiments.

[0162] For example, the multi-mode GNSS navigation source used in this invention may include existing GNSS navigation sources such as GPS, BDS, GLONASS, and GALILEO, as well as new GNSS navigation sources that may be established in the future. This invention may cover two, three, or more GNSS navigation sources. Moreover, for the same type of GNSS navigation source, the number of equipment sets included may be one or more, and this invention does not limit this.

[0163] The flight management system provided by the present invention is described below. The flight management system described below can be referred to in correspondence with the anti-spoofing detection method and data processing method described above.

[0164] Please refer to Figure 6 , Figure 6 This is an architecture diagram of the flight management system provided in an embodiment of the present invention. Figure 6 The embodiments selected two GNSS navigation sources: a first navigation source (e.g., GPS) and a second navigation source (e.g., BDS), with each type containing one set of equipment.

[0165] For example, a flight management system includes an anti-spoofing detection device 610 and a data processing device 620. The anti-spoofing detection device 610 includes a first navigation source spoofing detection module 611 and a second navigation source spoofing detection module 612. The data processing device 620 includes a navigation source selection module 621, a navigation position calculation module 622, an FMS guidance function module 623, and an FMS status display and control device module 624.

[0166] For example, the first navigation source deception detection module 611 is used to perform outer layer detection by acquiring navigation data of the first to fourth navigation sources and using the navigation data to perform deception detection calculation on the first navigation source.

[0167] The following example illustrates the application of GPS as the first navigation source, BDS as the second, DME as the third, and IRS as the fourth. It should be noted that the first and second navigation sources selected in this invention can be any of the GNSS navigation sources such as GPS, BDS, GLONASS, and GALILEO; the third navigation source is an IRS navigation source; and the fourth navigation source is a DME navigation source.

[0168] First, the pseudorange estimates of GPS and BDS satellites are calculated using IRS location and ephemeris information, and the equivalent pseudorange of DME is calculated using IRS location and DME navigation station location.

[0169] Then, the pseudoranges of GPS and BDS satellites are subtracted from their pseudorange estimates, and the slant ranges of DME satellites are subtracted from their equivalent pseudoranges to construct the first measurement equation. The spoofing detection quantity of each visible GPS satellite is calculated. The change in the statistical characteristics of the spoofing detection quantity can reflect whether the satellite signal has been spoofed.

[0170] Finally, the spoofing detection statistic corresponding to each GPS visible satellite is calculated based on the spoofing detection amount, and the spoofing detection statistic is compared with the first spoofing detection threshold. If the threshold is exceeded, the GPS visible satellite signal is determined to be spoofed.

[0171] Iterate through all visible GPS satellite signals, detect whether each visible GPS satellite is being spoofed, and generate GPS detection results.

[0172] If GPS spoofing is detected, the first navigation source spoofing detection module 611 sends an activation signal to the second navigation source spoofing detection module 612 to activate the inner layer detection.

[0173] Since the first navigation source deception detection module 611 uses navigation data from BDS, DME, and IRS to perform deception detection on GPS navigation data, its detection accuracy is higher, achieving pseudorange-level deception interference detection on GPS.

[0174] For example, the second navigation source deception detection module 612 is used to perform inner-layer detection by acquiring navigation data from the second to fourth navigation sources and using the navigation data to perform pseudo-range-level deception interference detection on the second navigation source. Specifically:

[0175] First, the pseudorange estimate of the BDS satellite is calculated using the IRS position and ephemeris information, and the equivalent pseudorange of the DME is calculated using the IRS position and the DME navigation station position.

[0176] Then, the difference between the BDS satellite pseudorange and the BDS pseudorange estimate is calculated, and the difference between the DME pseudorange and the DME equivalent pseudorange is calculated to construct the second measurement equation and calculate the deception detection amount for each BDS visible satellite.

[0177] Finally, the deception detection statistic for each BDS visible satellite is calculated based on the deception detection amount, and the deception detection statistic is compared with the deception detection threshold. If the threshold is exceeded, the BDS visible satellite signal is determined to be deceiving.

[0178] Iterate through all BDS visible satellite signals, detect whether each BDS visible satellite has been deceived, and generate BDS detection results.

[0179] For example, the navigation source selection module 621 is used to provide an automatic mode and a manual mode based on the detection results of the outer layer detection and the inner layer detection, as well as the pilot's manual selection result, and outputs the available navigation modes that have not been spoofed to the navigation position calculation module 622 in the following priority:

[0180] 1) When neither GPS nor BDS is deceived, the navigation position calculation module 622 adopts the normal GPS primary mode, and the navigation position calculation module 622 prioritizes the fusion of GPS with other navigation sources;

[0181] 2) When GPS is spoofed but BDS is not spoofed, the navigation position calculation module 622 adopts the BDS master mode. The navigation position calculation module 622 prioritizes the fusion of BDS with other navigation sources, which can achieve switching without loss of accuracy.

[0182] 3) When both GPS and BDS are spoofed, if there are enough available satellites, the navigation position calculation module 622 adopts the BDS and GPS interoperability mode, that is, it uses unspoofed GPS and BDS satellite signals to perform interoperable navigation position calculation.

[0183] 4) If GPS and BDS are both spoofed and there are insufficient available satellites, then the IRS / RADIO downgrade mode will be used.

[0184] It should be noted that the mode selection logic of priorities 1) to 4) above is based on the navigation source selection logic in automatic mode, but pilots can also manually select any of the above GPS primary mode, BDS primary mode, BDS and GPS interoperability mode, and IRS / RADIO downgrade mode.

[0185] For example, the FMS guidance function module 623 is used to generate guidance instructions according to the current flight plan of the aircraft and the FMS position information from the navigation position calculation module 622, so as to guide the aircraft to fly along the predetermined route.

[0186] For example, the FMS status display and control device module 624 is used to display various statuses and interfaces of the FMS in the cockpit, and can receive input from control devices such as cockpit keyboards and scroll wheels to realize human-machine interaction between the FMS and the pilot.

[0187] Therefore, this invention provides a two-layer deception interference detection method that combines inner-layer detection and outer-layer detection. By adding auxiliary GNSS sources and radio navigation facilities, it solves the problem that single-type GNSS navigation sources are easily deceived, while ensuring the navigation accuracy and availability of FMS in deception environments.

[0188] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preventing spoofing detection, characterized in that, The method includes: Select one navigation source as the first navigation source and another navigation source as the second navigation source from a plurality of preset navigation sources; The navigation data of the plurality of preset navigation sources is obtained and the navigation data is used to perform deception detection calculation on the first navigation source to determine whether the first navigation source has been deceived. If it is determined that the first navigation source has been deceived, the navigation data other than the first navigation source is used to perform a deception detection calculation on the second navigation source to determine whether the second navigation source has been deceived. If neither the first navigation source nor the second navigation source is deceived, the first mode is used to calculate the aircraft's navigation position; if the first navigation source is deceived but the second navigation source is not, the second mode is used to calculate the aircraft's navigation position; if the detection result is that both the first and second navigation sources are deceived and there is a usable, undeceived visible star, the third mode is used to calculate the aircraft's navigation position; if the detection result is that both the first and second navigation sources are deceived and there is no usable visible star, the fourth mode is used to calculate the aircraft's navigation position. The first mode is a mode that selects a first navigation source and merges it with other navigation sources other than the second navigation source; the second mode is a mode that selects a second navigation source and merges it with other navigation sources other than the first navigation source; the third mode is a mode that selects an unspoofed visible star from the first and second navigation sources and merges it with other navigation sources; and the fourth mode is a navigation mode that selects a third navigation source and merges it with other navigation sources other than the first and second navigation sources.

2. The anti-spoofing detection method according to claim 1, characterized in that, The step of using the navigation data to perform deception detection calculations on the first navigation source includes: Select a third navigation source and a fourth navigation source from the plurality of preset navigation sources; The pseudorange estimates of the first and second navigation sources are calculated based on the navigation data of the third navigation source, and the equivalent pseudorange of the fourth navigation source is calculated based on the navigation data of the third and fourth navigation sources. Based on the pseudorange estimates of the first and second navigation sources and the equivalent pseudorange of the fourth navigation source, calculate the deception detection quantity and deception detection statistics for each visible star in the first navigation source.

3. The anti-spoofing detection method according to claim 2, characterized in that, The step of calculating the spoofing detection quantity and spoofing detection statistic for each visible star in the first navigation source based on the pseudorange estimates of the first and second navigation sources and the equivalent pseudorange of the fourth navigation source includes: The pseudoranges of the first and second navigation sources are subtracted from their corresponding pseudorange estimates, and the slant range of the fourth navigation source is subtracted from its equivalent pseudorange to construct a first measurement equation. The deception detection amount of each visible star in the first navigation source is calculated based on the constructed first measurement equation.

4. The anti-spoofing detection method according to claim 3, characterized in that, The step of calculating the spoofing detection quantity and spoofing detection statistic for each visible star in the first navigation source based on the pseudorange estimates of the first and second navigation sources and the equivalent pseudorange of the fourth navigation source further includes: Calculate the first deception detection statistic corresponding to each visible star based on the deception detection statistic of the first navigation source; Compare the first deception detection statistic with the first preset deception detection threshold; If the first deception detection statistic exceeds the first preset deception detection threshold, it is determined that the signal of the visible star of the first navigation source has been deceiving. Iterate through all visible stars of the first navigation source to determine whether each visible star is being deceived, and output the detection result of the first navigation source.

5. The anti-spoofing detection method according to claim 4, characterized in that, If at least one visible star signal of the first navigation source is spoofed, then the first navigation source is determined to be spoofed.

6. The anti-spoofing detection method according to claim 2, characterized in that, The step of performing deception detection calculations on the second navigation source using navigation data other than the first navigation source includes: The pseudorange estimate of the second navigation source is calculated based on the navigation data of the third navigation source, and the equivalent pseudorange of the fourth navigation source is calculated based on the navigation data of the third navigation source and the fourth navigation source. The deception detection quantity and deception detection statistics for each visible star in the second navigation source are calculated based on the pseudorange estimate of the second navigation source and the equivalent pseudorange of the fourth navigation source.

7. The anti-spoofing detection method according to claim 6, characterized in that, The step of calculating the deception detection quantity and deception detection statistic for each visible star in the second navigation source based on the pseudorange estimate of the second navigation source and the equivalent pseudorange of the fourth navigation source includes: The pseudorange of the second navigation source is subtracted from its pseudorange estimate, and the slant range of the fourth navigation source is subtracted from its equivalent pseudorange to construct the second measurement equation. The deception detection amount for each visible star in the second navigation source is calculated based on the constructed second measurement equation.

8. The anti-spoofing detection method according to claim 7, characterized in that, The step of calculating the deception detection quantity and deception detection statistic for each visible star in the second navigation source based on the pseudorange estimate of the second navigation source and the equivalent pseudorange of the fourth navigation source further includes: Calculate the second deception detection statistic corresponding to each visible star based on the deception detection quantity of the second navigation source; Compare the second deception detection statistic with the second preset deception detection threshold; If the second deception detection statistic exceeds the second preset deception detection threshold, it is determined that the signal of the visible star of the second navigation source has been deceiving. Iterate through all visible stars of the second navigation source to determine whether each visible star is being deceived, and output the detection result of the second navigation source.

9. A data processing method, characterized in that, The method includes: Based on the detection result of any one of claims 1 to 8, a navigation mode is generated and the navigation position of the aircraft is calculated based on the navigation mode; The navigation modes include an automatic mode and four modes. The first mode is a mode that selects a first navigation source and merges it with other navigation sources other than the second navigation source. The second mode is a mode that selects a second navigation source and merges it with other navigation sources other than the first navigation source. The third mode is a mode that selects an unspoofed visible star from the first and second navigation sources and merges it with other navigation sources. The fourth mode is a navigation mode that selects a third navigation source and merges it with other navigation sources other than the first and second navigation sources.

10. The data processing method according to claim 9, characterized in that, The step of calculating the aircraft's navigation position based on the navigation mode includes: If the detection result shows that neither the first navigation source nor the second navigation source has been deceived, then the first mode is used to calculate the aircraft's navigation position. If the detection result is that the first navigation source is deceived and the second navigation source is not deceived, then the second mode is used to calculate the aircraft's navigation position; If the detection result is that both the first navigation source and the second navigation source are deceived and there are usable, undeceived visible stars, then the third mode is used to calculate the navigation position of the spacecraft. If the detection result is that both the first navigation source and the second navigation source are deceived and there are no usable visible stars, then the fourth mode is used to calculate the navigation position of the aircraft.

11. The data processing method according to claim 10, characterized in that, The method further includes: The navigation mode is displayed on a preset interface for the pilot to select; Upon receiving the pilot's execution command, it responds to the navigation mode corresponding to that command.

12. The data processing method according to claim 11, characterized in that, The step of displaying the navigation mode on a preset interface for the pilot to select includes: In automatic mode, the navigation source automatically selected by the flight management system, its corresponding navigation performance, and whether it is effective will be displayed.

13. The data processing method according to claim 11, characterized in that, The steps of displaying the navigation mode for the pilot to select include: In the first mode, the first column displays the navigation source that is currently merged with other navigation sources besides the second navigation source, the second column displays the corresponding navigation performance, and the third column displays whether the first mode is effective. If the detection result is that the first navigation source is deceived, the third column displays that the first mode is invalid and issues an alarm.

14. The data processing method according to claim 11, characterized in that, The steps of displaying the navigation mode for the pilot to select include: In the second mode, the flight management system prioritizes merging the second navigation source with other navigation sources besides the first navigation source, displays the currently merged navigation source in the first column, displays the corresponding navigation performance in the second column, and displays whether the second mode is effective in the third column. If the detection result is that the second navigation source is deceived, the second mode is invalid and an alarm is issued in the third column.

15. The data processing method according to claim 11, characterized in that, The steps of displaying the navigation mode for the pilot to select include: In the third mode, the flight management system selects a usable, unspoofed visible star from the first and second navigation sources and merges it with other navigation sources. The system displays the currently merged navigation source in the first column, the corresponding navigation performance in the second column, and whether the third mode is effective in the third column. If the detection result is that both the first and second navigation sources are spoofed and there is no usable visible star, the system displays that the third mode is invalid in the third column and issues an alarm.

16. The data processing method according to claim 11, characterized in that, The steps of displaying the navigation mode for the pilot to select include: In the fourth mode, the flight management system selects a third navigation source and merges it with other navigation sources besides the first and second navigation sources. The system displays the currently merged navigation source in its corresponding first column, displays the corresponding navigation performance in its corresponding second column, and displays whether the fourth mode is effective in its corresponding third column.

17. A flight management system, characterized in that, The system includes: An anti-spoofing detection device, used to perform the anti-spoofing detection method according to any one of claims 1 to 8; A data processing apparatus for performing the data processing method according to any one of claims 9 to 16.

18. The flight management system according to claim 17, characterized in that, The first and second navigation sources use any one of GPS, BDS, GLONASS, and GALILEO navigation sources, the third navigation source uses an IRS navigation source, and the fourth navigation source uses a DME navigation source.

Images