Method and device for detecting deception jamming based on multiple receivers

Abstract

The invention discloses a deception jamming detection method and device based on multiple receivers, and the method comprises the steps: describing the relation between satellite signals received by the receivers and the actual positions of satellites through building a pseudo-range measurement equation; by establishing a carrier phase measurement equation, the relation between the carrier phase of a satellite signal received by a receiver and the actual position of a satellite is described. Based on a pseudo-range measurement equation, a single difference and a double difference are defined, and a complete deception state and a partial real state are distinguished. A pseudo-range double-difference model and a carrier phase double-difference model are constructed, a final double-difference model is comprehensively formed, and the model reflects the change of a double-difference measurement value along with time and comprises fixed offset, a slope coefficient and a random error. The final double-difference model is used for calculation, and if the result is 0, deception jamming exists. The problem of how to improve the accuracy and reliability of GNSS deception detection is solved.

Description

Technical Field

[0001] The present application relates to the field of satellite navigation technology, and in particular to a deception interference detection method and device based on multiple receivers. Background Art

[0002] BeiDou Navigation Satellite System (BDS) is one of the world's three most mature satellite navigation systems, providing high-precision and highly reliable positioning, navigation and timing (PNT) services. However, GNSS signals are susceptible to deceptive interference during transmission, that is, sending false GNSS signals to mislead receivers and cause significant losses.

[0003] In order to deal with GNSS spoofing interference, the existing technology has proposed a variety of detection methods. Although the existing technology has achieved certain results, it still has shortcomings. Some methods need to rely on specific hardware or equipment, such as dual-antenna systems, which are limited in practical applications. In addition, some methods only use two receivers when dealing with complex environments or multiple spoofing methods, which limits their flexibility and extensiveness in practical applications and cannot maintain sufficient accuracy and reliability.

[0004] Therefore, how to improve the accuracy and reliability of GNSS spoofing detection is an urgent problem to be solved. Summary of the invention

[0005] In an embodiment of the present application, a multi-receiver based deception interference detection method is provided to solve the problem of how to improve the accuracy and reliability of GNSS deception detection.

[0006] In a first aspect, an embodiment of the present application provides a spoofing interference detection method based on multiple receivers, including: obtaining parameters required for establishing a pseudorange measurement equation, and establishing a pseudorange measurement equation based on the obtained parameters to describe the relationship between the satellite signal received by the receiver and the actual position of the satellite; wherein the pseudorange measurement equation has different expressions when there is a spoofing signal and when there is no spoofing signal; the parameters required for establishing the pseudorange measurement equation include: the geometric distance between the receiver and the satellite, the distance between the receiver and the spoofing transmitting antenna, and the clock error of the receiver and the satellite, and obtaining an additional clock error according to the type of spoofing signal, and obtaining the delay effect of the ionosphere and troposphere on the signal propagation path between the receiver and the satellite; obtaining the carrier phase periodic ambiguity, and establishing a carrier phase measurement equation to describe the relationship between the carrier phase of the satellite signal received by the receiver and the actual position of the satellite; wherein, the carrier The phase measurement equation has different expressions when there is a deception signal and when there is no deception signal; based on the pseudorange measurement equation, the pseudorange single difference and the carrier phase single difference between the two receivers, as well as the pseudorange double difference and the carrier phase double difference between the two receivers are defined; a complete deception state and a partially true state are defined; according to the complete deception state and the partially true state, a double difference model of pseudorange is established based on the pseudorange measurement equation; according to the complete deception state and the partially true state, a double difference model of carrier phase is established based on the carrier phase measurement equation; the double difference model of pseudorange and the double difference model of carrier phase are integrated to form a final double difference model, which represents the relationship between the double difference measurement value and time, including a fixed offset, a slope coefficient and a random error; the final double difference model is used to perform calculations to determine whether the calculation result is 0; if the calculation result is 0, it indicates that deception interference exists; if the calculation result is not 0, it indicates that deception interference does not exist.

[0007] In a possible implementation, before obtaining the parameters required to establish the pseudorange measurement equation, the method includes: performing a signal-to-noise ratio analysis on a satellite signal received by a receiver to determine whether the signal-to-noise ratio of the satellite signal is greater than or equal to a preset threshold; if the signal-to-noise ratio of the satellite signal is greater than or equal to the preset threshold, retaining the satellite signal; and if the signal-to-noise ratio of the satellite signal is less than the preset threshold, removing the satellite signal.

[0008] In one possible implementation, the pseudorange measurement equation in the presence of a spoofing signal is expressed as ;in, For in time When the satellite In the receiver The pseudorange measurements in To spoof signals reaching satellites The distance For receiver The distance from the spoofed transmitting antenna, is the speed of light, For receiver The clock error at time n is, is the additional clock error obtained according to the type of spoofing signal, is the measurement noise when there is a deception signal; the expression of the pseudo-range measurement equation when there is no deception signal is ;in, For in time When the satellite In the receiver The pseudorange measurements in For in time When the receiver With satellite The geometric distance between For satellite In time The clock error, is the ionosphere's influence on the receiver at time n. With satellite The delay effect of the signal propagation path between is the troposphere's influence on the receiver at time n With satellite The delay effect of the signal propagation path between At time n, the receiver Satellite The pseudorange measurement noise.

[0009] In one possible implementation, the carrier phase measurement equation in the presence of a spoofing signal is expressed as ;in, For the receiver In time Time to Satellite The carrier phase measurement value, is the spoofed value of the carrier phase period ambiguity, is the wavelength of the carrier; the expression of the carrier phase measurement equation when there is no deceptive signal is ;in, is the carrier phase periodic ambiguity.

[0010] In a possible implementation, the pseudorange measurement equation is based on defining the pseudorange single difference and carrier phase single difference between two receivers, and the pseudorange double difference and carrier phase double difference between two receivers, including: the expression of the pseudorange single difference and carrier phase single difference between two receivers is: ;in, For in time When the satellite With respect to two receivers and The pseudorange single difference or carrier phase single difference between For in time When the satellite In the receiver Pseudorange measurements or carrier phase measurements in For in time When the satellite In the receiver The pseudorange measurement value or carrier phase measurement value in the receiver; the pseudorange double difference between two receivers is defined as the difference between the pseudorange single differences between the two receivers; the carrier phase double difference between two receivers is defined as the difference between the carrier phase single differences between the two receivers; the expressions of the pseudorange double difference and carrier phase double difference between two receivers are: ;in; For in time When the satellite and satellite , relative to the two receivers and The double difference of pseudorange or carrier phase between For in time When the satellite With respect to two receivers and The pseudorange single difference or carrier phase single difference between For in time When the satellite With respect to two receivers and The pseudorange single difference or carrier phase single difference between them.

[0011] In a possible implementation, the definition of a fully deceptive state and a partially true state includes: a fully deceptive state is defined as: in this state, the measurement values ​​of the pseudorange and the carrier phase are both derived from deceptive signals; a partially true state is defined as: in this state, at least one measurement value of the pseudorange or the carrier phase is derived from a true signal.

[0012] In a possible implementation, the double-difference model of pseudorange is established based on the pseudorange measurement equation according to the complete deception state and the partial truth state, including: the expression of the double-difference model of pseudorange is: ;in, For in time When the satellite and satellite , relative to the two receivers and The double difference of the pseudorange measurements between It is a state of complete deception. For part of the real state, represents the pseudorange double difference noise at time n, is the offset of the pseudorange double difference changing with time under partial truth state, is the slope coefficient of the pseudorange double difference changing with time under partial truth conditions.

[0013] In a possible implementation, the double difference model of the carrier phase is established based on the carrier phase measurement equation according to the complete deception state and the partial truth state, including: the expression of the double difference model of the carrier phase is: ;in, is the time at which the satellite and satellite , relative to the two receivers and The double difference between the carrier phase measurements, It is a state of complete deception. For part of the real state, is the time-varying offset of the double difference of carrier phase in the complete deception state, For in time When the carrier phase double difference noise, is the offset of the carrier phase double difference changing with time under partial truth state, is the slope coefficient of the carrier phase double difference changing with time under partial truth state.

[0014] In a possible implementation, the double difference model of the integrated pseudorange and the double difference model of the carrier phase are used to form a final double difference model, including: the expression of the final double difference model is: ;in, is the final double difference function, represents the final double difference function that can be applied to the double difference of the measurements of pseudorange or carrier phase, is the fixed offset of the double difference of the pseudorange or carrier phase measurements, is the slope coefficient of the double difference of the pseudorange or carrier phase measurement over time, For in time The random error of the double difference of the pseudorange or carrier phase measurements.

[0015] In a second aspect, an embodiment of the present application provides a deception interference detection device based on multiple receivers, including: establishing a pseudorange measurement equation module, which is used to obtain parameters required for establishing the pseudorange measurement equation, and establishing the pseudorange measurement equation based on the obtained parameters to describe the relationship between the satellite signal received by the receiver and the actual position of the satellite; wherein the pseudorange measurement equation has different expressions when there is a deception signal and when there is no deception signal; the parameters required to establish the pseudorange measurement equation include: the geometric distance between the receiver and the satellite, the distance between the receiver and the deception transmitting antenna, and the clock error of the receiver and the satellite, and obtaining an additional clock error according to the type of deception signal, and obtaining the delay effect of the ionosphere and troposphere on the signal propagation path between the receiver and the satellite; establishing a carrier phase measurement equation module, which is used to obtain the carrier phase periodic ambiguity, and establishing a carrier phase measurement equation to describe the relationship between the carrier phase of the satellite signal received by the receiver and the actual position of the satellite; wherein the carrier phase measurement equation There are different expressions when there is a deception signal and when there is no deception signal; the first definition module is used to define the pseudorange single difference and carrier phase single difference between the two receivers, as well as the pseudorange double difference and carrier phase double difference between the two receivers based on the pseudorange measurement equation; the second definition module is used to define the complete deception state and the partial truth state; the model establishment module is used to establish the double difference model of pseudorange based on the pseudorange measurement equation according to the complete deception state and the partial truth state; the double difference model of carrier phase is established based on the carrier phase measurement equation according to the complete deception state and the partial truth state; the final double difference model formation module is used to integrate the double difference model of pseudorange and the double difference model of carrier phase to form the final double difference model, the final double difference model represents the relationship between the double difference measurement value and time, including fixed offset, slope coefficient and random error; the final double difference model is used to calculate and determine whether the calculation result is 0; if the calculation result is 0, it indicates that deception interference exists; if the calculation result is not 0, it indicates that deception interference does not exist.

[0016] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects: The embodiment of the present application provides a deception interference detection method based on multiple receivers, which comprehensively considers key parameters such as the geometric distance between the receiver and the satellite, the distance between the receiver and the deception transmitting antenna, and the clock error of the receiver and the satellite, ensuring the accuracy of the pseudorange measurement equation. The additional clock error caused by the deception signal type, as well as the delay effect of the ionosphere and troposphere on the signal propagation path, are additionally considered to further improve the accuracy of the equation. Based on the pseudorange measurement equation, the single difference and double difference of pseudorange, as well as the single difference and double difference of carrier phase are defined, providing a rich data basis for deception detection. According to the complete deception state and the partial true state, the double difference model of pseudorange and the double difference model of carrier phase are established respectively, realizing the accurate identification of deception signals. The double difference model of pseudorange and the double difference model of carrier phase are combined to form a final double difference model, which can represent the relationship between the double difference measurement value and time, including fixed offset, slope coefficient and random error. The final double difference model is used for calculation. When the calculation result is 0, it is judged that there is deception interference, which provides a strong guarantee for the safe use of GNSS system. This application achieves fast and accurate detection of spoofing signals, improves the efficiency and accuracy of GNSS spoofing detection, and is applicable to a variety of spoofing scenarios and signal types, with strong versatility and adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments of the present application or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A flowchart of a deception interference detection method based on multiple receivers provided in an embodiment of the present application; Figure 2 A schematic diagram of a pseudorange double difference result provided in an embodiment of the present application; Figure 3 A schematic diagram of a carrier phase double difference for a single spoofing scenario provided in an embodiment of the present application; Figure 4 A schematic diagram of a receiver position and a spoofing source position provided in an embodiment of the present application; Figure 5 A comparison diagram of spoofing detection results using pseudorange and carrier phase provided in an embodiment of the present application; Figure 6 A schematic diagram of a multi-receiver spoofing detection result provided in an embodiment of the present application; Figure 7 A schematic diagram of a deception interference detection device based on multiple receivers provided in an embodiment of the present application; Figure 8 A schematic diagram of a multi-receiver based deception interference detection server provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] The following describes some of the techniques involved in the embodiments of the present application to facilitate understanding, and they should be considered as merely exemplary. Therefore, it should be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, some descriptions of well-known functions and structures are omitted in the following description.

[0021] The embodiment of the present application provides a deception interference detection method based on multiple receivers, such as Figure 1 As shown, the method includes steps S101 to S110. Among them, Figure 1 This is only an execution order shown in the embodiment of the present application, and does not represent the only execution order of a deception interference detection method based on multiple receivers. In the case where the final result can be achieved, Figure 1 The steps shown may be performed in parallel or reversed.

[0022] GNSS spoofing interference is a navigation signal interference method that first uses suppression interference to make the receiver loop unlock, and then generates a simulated GNSS signal to deceive the receiver, thereby deceiving the receiver. Considering that the deception interference signals often come from the same transmitter and are limited by the cost of deception, the present application can use an antenna with anti-suppression capability at the antenna end to effectively shield or weaken the suppression interference signal. The design of the anti-suppression antenna should be able to distinguish between real GNSS signals and suppression interference signals to ensure that the receiver can continue to lock and receive real signals. Two or more GNSS receivers are configured to receive signals from different satellites at the same time. The measurements of the pseudorange and carrier phase received by these receivers are calculated using the final double difference model. The calculation results can be used to analyze whether there is deception interference.

[0023] S101: Acquire parameters required for establishing a pseudo-range measurement equation, and establish a pseudo-range measurement equation based on the acquired parameters to describe the relationship between the satellite signal received by the receiver and the actual position of the satellite. The pseudo-range measurement equation has different expressions when there is a spoofing signal and when there is no spoofing signal.

[0024] Specifically, before obtaining the parameters required to establish the pseudorange measurement equation, the method includes: performing a signal-to-noise ratio analysis on the satellite signal received by the receiver to determine whether the signal-to-noise ratio of the satellite signal is greater than or equal to a preset threshold. If the signal-to-noise ratio of the satellite signal is greater than or equal to the preset threshold, the satellite signal is retained. If the signal-to-noise ratio of the satellite signal is less than the preset threshold, the satellite signal is removed.

[0025] It should be noted that the signal-to-noise ratio (SNR) is an important indicator for measuring the quality of the received satellite signal. The higher the signal-to-noise ratio, the better the signal quality and the less noise and interference. The preset threshold is usually set according to the performance of the receiver and the application requirements. For example, suppose there is a medium-performance receiver working under normal environmental conditions. Based on experience or experimental data, a preset threshold can be set to 25dB-Hz (decibel-Hertz). This means that if the signal-to-noise ratio of the received satellite signal is greater than or equal to 25dB-Hz, then the signal is considered to be of good quality and can be used for subsequent pseudo-range measurement and calculation. If the signal-to-noise ratio of the received satellite signal is less than 25dB-Hz, then the signal may be affected by noise or interference, the quality is poor, and it is not suitable for pseudo-range measurement and calculation, so it should be removed. This preset threshold is only an example and is not applicable to all situations. This application is not limited to this preset threshold. In actual applications, the preset threshold needs to be adjusted according to the performance of the receiver, environmental conditions and application requirements.

[0026] The parameters required to establish the pseudorange measurement equation include: the geometric distance between the receiver and the satellite, the distance between the receiver and the deceptive transmitting antenna, and the clock error of the receiver and the satellite. Additional clock errors are obtained based on the type of deceptive signal, and the delay effect of the ionosphere and troposphere on the signal propagation path between the receiver and the satellite is obtained.

[0027] The expression of the pseudo-range measurement equation in the presence of a deceptive signal is: .in, For in time When the satellite In the receiver The pseudorange measurements in To spoof signals reaching satellites The distance For receiver The distance from the spoofed transmitting antenna, is the speed of light, For receiver The clock error at time n is, is the additional clock error obtained according to the type of spoofing signal, is the measurement noise in the presence of spoofing signals.

[0028] The pseudo-range measurement equation when there is no deception signal is expressed as .in, For in time When the satellite In the receiver The pseudorange measurements in For in time When the receiver With satellite The geometric distance between For satellite In time The clock error, is the ionosphere's influence on the receiver at time n. With satellite The delay effect of the signal propagation path between is the troposphere's influence on the receiver at time n With satellite The delay effect of the signal propagation path between At time n, the receiver Satellite The pseudorange measurement noise.

[0029] It should be noted that in the presence of deceptive signals, represents the sum of normal measurement noise and the additional noise introduced by the deception signal, that is, the measurement noise when there is a deception signal. In the absence of a deception signal, represents normal pseudorange measurement noise.

[0030] S102: Acquire carrier phase periodic ambiguity and establish a carrier phase measurement equation to describe the relationship between the carrier phase of the satellite signal received by the receiver and the actual position of the satellite. The carrier phase measurement equation has different expressions when there is a spoofing signal and when there is no spoofing signal.

[0031] The expression of the carrier phase measurement equation in the presence of a spoofing signal is: .in, For receiver In time Time to Satellite The carrier phase measurement value, is the spoofed value of the carrier phase period ambiguity, is the wavelength of the carrier.

[0032] The expression of the carrier phase measurement equation when there is no deception signal is: .in, is the carrier phase periodic ambiguity.

[0033] It needs to be explained that In the absence of a spoofing signal, the receiver With satellite The true value of the integer of the carrier phase period ambiguity between . In the presence of a deceptive signal, the receiver cannot accurately determine the integer part of the carrier phase cycle due to the influence of the deceptive signal, resulting in a deceptive ambiguity value. This value is usually different from the true value There are differences and may lead to deviations or errors in positioning results.

[0034] S103: Based on the pseudorange measurement equation, define a pseudorange single difference and a carrier phase single difference between two receivers, and a pseudorange double difference and a carrier phase double difference between two receivers.

[0035] Specifically, in GNSS (Global Navigation Satellite System) positioning technology, pseudorange and carrier phase measurements are key information for determining the receiver's position. However, these measurements may be interfered with by spoofing signals, resulting in inaccurate positioning results. In order to identify measurements generated by spoofing signals, the double difference characteristics of pseudorange or carrier phase differences can be used.

[0036] Based on the pseudorange measurement equation, the pseudorange single difference and carrier phase single difference between two receivers, as well as the pseudorange double difference and carrier phase double difference between two receivers are defined, including: The expressions of pseudorange single difference and carrier phase single difference between two receivers are: .in, For in time When the satellite With respect to two receivers and The pseudorange single difference or carrier phase single difference between For in time When the satellite In the receiver Pseudorange measurements or carrier phase measurements in For in time When the satellite In the receiver Pseudorange measurements or carrier phase measurements in .

[0037] The double difference of pseudoranges between two receivers is defined as the difference between the single differences of pseudoranges between the two receivers.

[0038] The double difference of the carrier phase between two receivers is defined as the difference between the single differences of the carrier phase between the two receivers.

[0039] The expressions of the pseudorange double difference and carrier phase double difference between the two receivers are: .in. For in time When the satellite and satellite , relative to the two receivers and The double difference of pseudorange or carrier phase between For in time When the satellite With respect to two receivers and The pseudorange single difference or carrier phase single difference between For in time When the satellite With respect to two receivers and The pseudorange single difference or carrier phase single difference between them.

[0040] Furthermore, the expressions of the pseudorange double difference and carrier phase double difference between two receivers improve the accuracy and reliability of the measurements by eliminating some common error sources, such as satellite clock error, receiver clock error, etc. In GNSS positioning, spoofing signals may interfere with pseudorange and carrier phase measurements, resulting in inaccurate positioning results. However, since spoofing signals are usually difficult to maintain consistency between all satellites and all receivers, by calculating the pseudorange double difference and carrier phase double difference, it is easier to identify abnormal measurements introduced by spoofing signals. These abnormal measurements will show different patterns or characteristics from normal measurements, thereby providing a means to identify spoofing signals.

[0041] S104: Define a completely deceptive state and a partially truthful state.

[0042] The full deception state is defined as: in this state, the measurements of pseudorange and carrier phase are all derived from the deception signal.

[0043] Specifically, in this full deception state, it is assumed that the measurements of pseudorange and carrier phase in the double difference are all derived from the deception signal. This means that if the result of the double difference expression does not match the expectation, or shows an abnormal pattern, such as abnormal fluctuations, deviations, etc., it indicates the presence of a deception signal. In this state, since all measurement data have been tampered with or forged, they cannot accurately reflect the true position of the receiver or its relative relationship with other satellites.

[0044] The partially true state is defined as a state in which at least one of the pseudorange or carrier phase measurements is derived from a true signal.

[0045] Specifically, in this partially true state, it is assumed that at least one of the measurements in the double difference is derived from a true signal. This means that if the result of the double difference expression is consistent with expectations or exhibits a normal pattern, it indicates that at least part of the measurements are true and can be used for navigation and positioning calculations.

[0046] S105: According to the complete deception state and the partial truth state, a double difference model of pseudorange is established based on the pseudorange measurement equation.

[0047] Specifically, the establishment of the double difference model of pseudorange is derived from the expression of the pseudorange double difference of the deception error when the deception signal is used for pseudorange measurement under a complete deception state, and the pseudorange double difference of the deception error under a partial truth state, which shows the characteristics of an affine function over time.

[0048] Furthermore, the pseudorange double difference expression of the deception error when the deception signal is used for pseudorange measurement is: .in, Indicates a state of complete deception Next, in time , for satellite and satellite , relative to the same pair of receivers and The double difference of the pseudorange measurements between For deceptive errors, For in time When the satellite and satellite , relative to the same pair of receivers and The pseudorange double difference between the spoofing errors.

[0049] Furthermore, in the partial truth state, the double difference of pseudorange is usually not zero mean, and there is no single expression that can accurately describe its characteristics. However, in a sufficiently short time, it can be observed that the change of the double difference of pseudorange with deception error over time shows the characteristics of an affine function. This means that although the double difference in the partial truth state is complex and changeable, its change still follows a certain linear law on a short time scale.

[0050] Figure 2 Schematic diagram of pseudorange double difference results provided in the embodiment of the present application. Figure 2 The figure shows the pseudo-range double difference in a deception scenario tracking real and deception signals. By comparing the double differences of all real and deception signal combinations, it can be seen that in the full deception state, the double difference is close to zero, indicating that the deception error is effectively offset in the double difference calculation. In the partial truth state, the double difference is not zero, reflecting the significant impact of the deception error on the pseudo-range double difference. In addition, the figure also shows the double difference results when the deception system is located at 500 meters and 600 meters away from the two receivers, further verifying the correctness of the above analysis.

[0051] According to the complete deception state and the partial truth state, a double difference model of pseudorange is established based on the pseudorange measurement equation, including: The expression of the double difference model of pseudorange is: .in, For in time When the satellite and satellite , relative to the two receivers and The double difference of the pseudorange measurements between It is a state of complete deception. For part of the real state, represents the pseudorange double difference noise at time n, is the offset of the pseudorange double difference changing with time under partial truth state, is the slope coefficient of the pseudorange double difference changing with time under partial truth conditions.

[0052] It should be noted that the value of time n is an integer. Under this condition, the pseudorange double difference presents more complex characteristics. and are unknown, and they are determined by the receiver and , and satellite The pseudo-range double difference noise is determined by the specific configuration of the satellite. is defined as white noise with zero mean Gaussian distribution. This means The mean of is 0 and is independent at different time points, that is, it obeys the normal distribution and the values ​​at different time points are unrelated.

[0053] S106: According to the complete deception state and the partial truth state, a double difference model of the carrier phase is established based on a carrier phase measurement equation.

[0054] Specifically, in a completely deceptive state, the expression of the double difference of the carrier phase when the deceptive signal is used to measure the carrier phase is: .in, is the state of complete deception, at time n, for the satellite and satellite , relative to the same pair of receivers and The double difference between the carrier phase measurements, is the wavelength of the carrier, is the double difference of the integer ambiguity, For in time The noise double difference when .

[0055] Figure 3 Schematic diagram of carrier phase double difference for a single spoofing scenario provided by an embodiment of the present application. Figure 3 As shown, assuming that It is constant. In the analysis of the results of the carrier phase double difference and pseudorange double difference, if the double difference result of a certain PRN number is found to be 0, this is usually an unusual phenomenon and may indicate the presence of deception interference. Among them, the PRN number is a pseudo-random noise code, which is used to uniquely identify a satellite. In normal navigation signal reception, due to various errors, such as atmospheric delay, receiver noise, etc., the double difference value is rarely exactly 0. Once a PRN number with a double difference of 0 is detected, a deception interference alarm is issued, an abnormal star sign is output, and the abnormal PRN is shielded from participating in the solution to ensure that the output PNT information comes from a real and credible satellite.

[0056] According to the complete deception state and the partial truth state, a double difference model of the carrier phase is established based on the carrier phase measurement equation, including: The expression of the double difference model of the carrier phase is: .in, is the time at which the satellite and satellite , relative to the two receivers and The double difference between the carrier phase measurements, It is a state of complete deception. For part of the real state, is the time-varying offset of the double difference of carrier phase in the complete deception state, For in time When the carrier phase double difference noise, is the offset of the carrier phase double difference changing with time under partial truth state, is the slope coefficient of the carrier phase double difference changing with time under partial truth state.

[0057] It should be noted that the value of time n is an integer. is defined as white noise with zero mean Gaussian distribution. This means The mean of is 0 and is independent at different time points, that is, it obeys the normal distribution and the values ​​at different time points are unrelated. , and The value depends on the receiver and , and satellite and satellite Specific configuration.

[0058] S107: The double difference model of the pseudorange and the double difference model of the carrier phase are integrated to form a final double difference model, which represents the relationship between the double difference measurement values ​​and time, including a fixed offset, a slope coefficient, and a random error.

[0059] The double difference model of pseudorange and the double difference model of carrier phase are integrated to form the final double difference model, including: The expression of the final double difference model is: .in, is the final double difference function, represents the final double difference function that can be applied to the double difference of the measurements of pseudorange or carrier phase, is the fixed offset of the double difference of the pseudorange or carrier phase measurements, is the slope coefficient of the double difference of the pseudorange or carrier phase measurement over time, For in time The random error of the double difference of the pseudorange or carrier phase measurements.

[0060] S108: Calculate using the final double-difference model to determine whether the calculation result is 0.

[0061] If the calculation result is 0, that is, the judgment result is yes, step S109 is executed: indicating that deception interference exists.

[0062] If the calculation result is not 0, that is, the judgment result is no, step S110 is executed: indicating that there is no deceptive interference.

[0063] Specifically, the calculation result of the final double-difference model of the real satellite signal is a dynamic value that reflects the relative position and velocity changes between satellites. Since satellites move in space according to predetermined orbits, the geometric relationship between them and the receiver is constantly changing, which leads to fluctuations in the double-difference measurement value. However, when there is deception interference in the sky, the situation is completely different. Deception interference technology usually uses the same interference source to simulate multiple satellite signals. These simulated signals are highly correlated in time, and because they all come from the same source, their double-difference results often show abnormal consistency, that is, the double-difference result is 0, and lacks the variability that real satellite signals should have. This is because the deception signal is designed to have the same error characteristics when it is generated, resulting in the lack of variability in the double-difference measurement results of real satellite signals.

[0064] This application can effectively identify and address deception interference problems in satellite navigation systems. Whether in an environment with only real satellite signals, only deception satellite signals, or a combination of real satellites and deception satellite signals, the technology can work stably to ensure that the receiver can output reliable and trustworthy PNT (positioning, navigation and timing) information.

[0065] When there are only real signals in the sky, under real-time monitoring, no alarm will be triggered and user use will not be affected. When there are only spoofed signals in the sky, the spoofed signals can be detected, thereby generating an alarm to protect user safety. When there are both real and spoofed signals in the sky, it is possible to effectively distinguish which signals are real and usable, and which signals are spoofed interference and need to be isolated. In this way, only real data can be used in subsequent GNSS services such as positioning, thereby ensuring user safety.

[0066] Figure 4 Schematic diagram of the receiver position and spoofing source position provided in the embodiment of the present application. In the simulation scenario, 7 satellites are set up, each of which transmits real signals and spoofing signals. At the same time, Rx1 to Rx 10 There are 10 receiver monitoring points in total. The specific locations and distribution of these points are as follows: Figure 4 In order to fully evaluate the performance of the technology, multiple verification scenarios were designed, each of which included different receiver point and distance combinations. The specific verification scenarios and the corresponding receiver point and distance settings are shown in the table. These scenarios cover a variety of situations from short distances to long distances to fully test the performance of the technology under different conditions.

[0067] Table 1 is the experimental record. In the experiment, the receiver power-on time was recorded as the horizontal axis, and the average value of the real signal was recorded as the vertical axis. The experimental results show that for the receiver combination at least 10 meters apart, most real signals are correctly identified within 30 seconds. Unrecognized signals are regarded as spoofed signals, which further verifies the accuracy and reliability of the technology.

[0068] Table 1

[0069] Figure 5 A comparison chart of spoofing detection results using pseudorange and carrier phase provided in an embodiment of the present application. Figure 5 The pseudorange is 1b, and the carrier phase is 2b. The experimental results show that good performance is exhibited at a receiving distance greater than or equal to 5 meters. This result verifies the effectiveness and reliability of this application in dealing with deception interference. In the scenarios of 35 meters and 20 meters, the performance of the deception suppression method based on pseudorange is slightly reduced. This is because the relative position relationship between the receiver and the satellite has changed, resulting in changes in the signal propagation path and interference characteristics. In addition, the deception detection results in the two scenarios Sc.1 and Sc.2 are also compared. The experimental results show that the performance of Sc.1 is better than that of Sc.2, which further confirms that there is a correlation between the position of the receiver and the deception detection results. Specifically, different receiver positions may lead to differences in signal reception quality, interference strength, and signal propagation path, thereby affecting the performance of deception detection.

[0070] Figure 6 Schematic diagram of multi-receiver spoofing detection results provided by an embodiment of the present application. Figure 6As shown in the figure, in the 5-meter scenario, when the receiver operation time reaches 30 seconds or more, the spoofing signals are successfully excluded. However, in the shorter operation time, that is, less than 30 seconds, some spoofing signals are not immediately identified. This may be because the received signal data is not enough to support the accurate operation of the spoofing detection algorithm in a short time, or because the difference between the spoofing signal and the real signal is not obvious enough in the initial stage. In the 50-meter scenario, the spoofing signals are successfully excluded regardless of the operation time. This shows that when the receiver spacing is large, the difference between the spoofing signal and the real signal is more obvious, making it easier to detect. By comparing the receiver combinations with different spacings, it is found that increasing the number of receivers can significantly improve the spoofing signal identification performance of receivers with closer distances. This is because multiple receivers can provide more signal data. For the receiver combinations with larger spacing, as shown by the pink, light blue, green and purple lines in the 50-meter scenario, although the spoofing signals are eventually excluded, increasing the number of receivers may further shorten the identification time of the spoofing signals. This is because multiple receivers can receive signals from different angles and positions, thereby capturing the characteristics of the spoofing signals more comprehensively.

[0071] The embodiment of the present application also provides a deception interference detection device 700 based on multiple receivers, such as Figure 7 As shown, the device includes: a module 701 for establishing a pseudorange measurement equation, a module 702 for establishing a carrier phase measurement equation, a first definition module 703, a second definition module 704, a model establishment module 705 and a final double difference model formation module 706.

[0072] The pseudo-range measurement equation establishment module 701 is used to obtain the parameters required for establishing the pseudo-range measurement equation, and establish the pseudo-range measurement equation based on the obtained parameters to describe the relationship between the satellite signal received by the receiver and the actual position of the satellite. The pseudo-range measurement equation has different expressions when there is a spoofing signal and when there is no spoofing signal. The parameters required for establishing the pseudo-range measurement equation include: the geometric distance between the receiver and the satellite, the distance between the receiver and the spoofing transmitting antenna, and the clock error of the receiver and the satellite, and obtain the additional clock error according to the type of the spoofing signal, and obtain the delay effect of the ionosphere and troposphere on the signal propagation path between the receiver and the satellite.

[0073] The carrier phase measurement equation establishment module 702 is used to obtain the carrier phase periodic ambiguity and establish a carrier phase measurement equation to describe the relationship between the carrier phase of the satellite signal received by the receiver and the actual position of the satellite. The carrier phase measurement equation has different expressions when there is a spoofing signal and when there is no spoofing signal.

[0074] The first definition module 703 is used to define the pseudorange single difference and carrier phase single difference between two receivers, and the pseudorange double difference and carrier phase double difference between two receivers based on the pseudorange measurement equation.

[0075] The second definition module 704 is used to define a completely deceptive state and a partially true state.

[0076] The model building module 705 is used to build a double difference model of pseudorange based on the pseudorange measurement equation according to the complete deception state and the partial truth state. According to the complete deception state and the partial truth state, a double difference model of carrier phase is built based on the carrier phase measurement equation.

[0077] The final double-difference model forming module 706 is used to integrate the double-difference model of pseudorange and the double-difference model of carrier phase to form a final double-difference model, which represents the relationship between the double-difference measurement value and time, including fixed offset, slope coefficient and random error. The final double-difference model is used to perform calculations to determine whether the calculation result is 0; if the calculation result is 0, it indicates that deception interference exists; if the calculation result is not 0, it indicates that there is no deception interference.

[0078] Some modules in the apparatus described in the present application can be described in the general context of computer executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0079] The devices or modules described in the above application embodiments can be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, the above devices are described in various modules according to their functions. When implementing the embodiments of the present application, the functions of each module can be implemented in the same or multiple software and / or hardware. Of course, the module that implements a certain function can also be implemented by combining multiple sub-modules or sub-units.

[0080] The methods, devices or modules described in this application can be implemented in the form of computer-readable program codes. The controller can be implemented in any appropriate manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program codes (such as software or firmware) that can be executed by the (micro)processor, logic gates, switches, application-specific integrated circuits (English: Application Specific Integrated Circuit, referred to as: ASIC), programmable logic controllers and embedded microcontrollers. Examples of controllers include but are not limited to the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that in addition to implementing the controller in the form of pure computer-readable program codes, the controller can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, this controller can be considered as a hardware component, and the devices included in it for implementing various functions can also be regarded as structures within the hardware component. Or even, the means for realizing various functions may be regarded as both a software module for realizing the method and a structure within a hardware component.

[0081] like Figure 8 As shown, an embodiment of the present application also provides a deception interference detection server based on multiple receivers, including a memory 801 and a processor 802; the memory 801 is used to store computer executable instructions; the processor 802 is used to execute computer executable instructions to implement a deception interference detection method based on multiple receivers described above in an embodiment of the present application.

[0082] An embodiment of the present application also provides a computer-readable storage medium, which stores executable instructions. When a computer executes the executable instructions, it can implement the deception interference detection method based on multiple receivers described above in the embodiment of the present application.

[0083] It can be seen from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary hardware. Based on this understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, or it can be reflected in the implementation process of data migration. The computer software product can be stored in a storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a mobile terminal, a server, or a network device, etc.) to execute the method described in the embodiment of the present application.

[0084] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. All or part of this application can be used in many general or special computer system environments or configurations.

[0085] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A deception interference detection method based on multiple receivers, characterized in that: include: Acquire parameters required for establishing a pseudorange measurement equation, and establish a pseudorange measurement equation based on the acquired parameters to describe the relationship between the satellite signal received by the receiver and the actual position of the satellite; wherein the pseudorange measurement equation has different expressions when there is a spoofing signal and when there is no spoofing signal; The parameters required to establish the pseudo-range measurement equation include: the geometric distance between the receiver and the satellite, the distance between the receiver and the deceptive transmitting antenna, and the clock errors of the receiver and the satellite. The additional clock error is obtained according to the type of deceptive signal, and the delay effect of the ionosphere and troposphere on the signal propagation path between the receiver and the satellite is obtained. Obtaining carrier phase periodic ambiguity and establishing a carrier phase measurement equation to describe the relationship between the carrier phase of the satellite signal received by the receiver and the actual position of the satellite; wherein the carrier phase measurement equation has different expressions when there is a deception signal and when there is no deception signal; Based on the pseudorange measurement equation, the pseudorange single difference and carrier phase single difference between two receivers, as well as the pseudorange double difference and carrier phase double difference between two receivers are defined; Define states of total deception and states of partial truth; According to the complete deception state and the partial truth state, a double difference model of pseudorange is established based on the pseudorange measurement equation; According to the complete deception state and the partial truth state, a double difference model of carrier phase is established based on the carrier phase measurement equation; The double difference model of pseudorange and the double difference model of carrier phase are integrated to form a final double difference model, which represents the relationship between the double difference measurement value and time, including fixed offset, slope coefficient and random error; The final double-difference model is used for calculation to determine whether the calculation result is 0; if the calculation result is 0, it indicates that deception interference exists; if the calculation result is not 0, it indicates that there is no deception interference.

2. The method for detecting deceptive interference based on multiple receivers according to claim 1, characterized in that: Before obtaining the parameters required for establishing the pseudorange measurement equation, the method includes: Performing a signal-to-noise ratio analysis on the satellite signal received by the receiver to determine whether the signal-to-noise ratio of the satellite signal is greater than or equal to a preset threshold; If the signal-to-noise ratio of the satellite signal is greater than or equal to a preset threshold, the satellite signal is retained; If the signal-to-noise ratio of the satellite signal is less than a preset threshold, the satellite signal is removed.

3. The method for detecting deceptive interference based on multiple receivers according to claim 1, characterized in that: The expression of the pseudo-range measurement equation in the presence of a deceptive signal is: ;in, For in time When the satellite In the receiver The pseudorange measurements in To spoof signals reaching satellites The distance For receiver The distance from the spoofed transmitting antenna, is the speed of light, For receiver The clock error at time n is, is the additional clock error obtained according to the type of spoofing signal, is the measurement noise in the presence of spoofing signals; The pseudo-range measurement equation when there is no deception signal is expressed as ;in, For in time When the satellite In the receiver The pseudorange measurements in For in time When the receiver With satellite The geometric distance between For satellite In time The clock error, is the ionosphere's influence on the receiver at time n. With satellite The delay effect of the signal propagation path between is the troposphere's influence on the receiver at time n With satellite The delay effect of the signal propagation path between At time n, the receiver Satellite The pseudorange measurement noise.

4. The method for detecting deceptive interference based on multiple receivers according to claim 3, characterized in that: The expression of the carrier phase measurement equation in the presence of a spoofing signal is: ;in, For receiver In time Time to Satellite The carrier phase measurement value, is the spoofed value of the carrier phase period ambiguity, is the wavelength of the carrier; The expression of the carrier phase measurement equation when there is no deception signal is: ;in, is the carrier phase periodic ambiguity.

5. The method for detecting deceptive interference based on multiple receivers according to claim 1, characterized in that: The method of defining a pseudorange single difference and a carrier phase single difference between two receivers, and a pseudorange double difference and a carrier phase double difference between two receivers based on a pseudorange measurement equation includes: The expressions of pseudorange single difference and carrier phase single difference between two receivers are: ;in, For in time When the satellite With respect to two receivers and The pseudorange single difference or carrier phase single difference between For in time When the satellite In the receiver Pseudorange measurements or carrier phase measurements in For in time When the satellite In the receiver Pseudorange measurements or carrier phase measurements in ; The double difference of pseudoranges between two receivers is defined as the difference between the single differences of pseudoranges between the two receivers; The double difference of the carrier phase between two receivers is defined as the difference between the single differences of the carrier phase between the two receivers; The expressions of the pseudorange double difference and carrier phase double difference between the two receivers are: ;in; For in time When the satellite and satellite , relative to the two receivers and The double difference of pseudorange or carrier phase between For in time When the satellite With respect to two receivers and The pseudorange single difference or carrier phase single difference between For in time When the satellite With respect to two receivers and The pseudorange single difference or carrier phase single difference between them.

6. The method for detecting deceptive interference based on multiple receivers according to claim 1, characterized in that: The definitions of fully deceptive states and partially truthful states include: The full deception state is defined as: in this state, the measurements of pseudorange and carrier phase are derived from the deception signal; The partially true state is defined as a state in which at least one of the pseudorange or carrier phase measurements is derived from a true signal.

7. The method for detecting deceptive interference based on multiple receivers according to claim 1, characterized in that: The method of establishing a double-difference model of pseudorange based on a pseudorange measurement equation according to a complete deception state and a partial truth state includes: The expression of the double difference model of pseudorange is: ;in, For in time When the satellite and satellite , relative to the two receivers and The double difference of the pseudorange measurements between It is a state of complete deception. For part of the real state, represents the pseudorange double difference noise at time n, is the offset of the pseudorange double difference changing with time under partial truth state, is the slope coefficient of the pseudorange double difference changing with time under partial truth conditions.

8. The method for detecting deceptive interference based on multiple receivers according to claim 1, characterized in that: The double difference model of carrier phase is established based on the carrier phase measurement equation according to the complete deception state and the partial truth state, including: The expression of the double difference model of carrier phase is: ;in, is the time at which the satellite and satellite , relative to the two receivers and The double difference between the carrier phase measurements, It is a state of complete deception. For part of the real state, is the time-varying offset of the double difference of carrier phase in the complete deception state, For in time When the carrier phase double difference noise, is the offset of the carrier phase double difference changing with time under partial truth state, is the slope coefficient of the carrier phase double difference changing with time under partial truth state.

9. The method for detecting deceptive interference based on multiple receivers according to claim 1, characterized in that: The double difference model of the integrated pseudorange and the double difference model of the carrier phase are used to form a final double difference model, including: The final double difference model is expressed as: ;in, is the final double difference function, represents the final double difference function that can be applied to the double difference of the measurements of pseudorange or carrier phase, is the fixed offset of the double difference of the pseudorange or carrier phase measurements, is the slope coefficient of the double difference of the pseudorange or carrier phase measurement over time, For in time The random error of the double difference of the pseudorange or carrier phase measurements.

10. A deception interference detection device based on multiple receivers, characterized in that: include: A pseudo-range measurement equation module is established to obtain the parameters required for establishing the pseudo-range measurement equation, and the pseudo-range measurement equation is established based on the obtained parameters to describe the relationship between the satellite signal received by the receiver and the actual position of the satellite; wherein the pseudo-range measurement equation has different expressions when there is a deception signal and when there is no deception signal; the parameters required for establishing the pseudo-range measurement equation include: the geometric distance between the receiver and the satellite, the distance between the receiver and the deception transmitting antenna, and the clock error of the receiver and the satellite, and the additional clock error is obtained according to the type of the deception signal, and the delay effect of the ionosphere and troposphere on the signal propagation path between the receiver and the satellite is obtained; A carrier phase measurement equation module is established to obtain carrier phase periodic ambiguity, and a carrier phase measurement equation is established to describe the relationship between the carrier phase of the satellite signal received by the receiver and the actual position of the satellite; wherein the carrier phase measurement equation has different expressions when there is a deception signal and when there is no deception signal; A first definition module is used to define a pseudorange single difference and a carrier phase single difference between two receivers, and a pseudorange double difference and a carrier phase double difference between two receivers based on a pseudorange measurement equation; The second definition module is used to define a completely deceptive state and a partially true state; A model building module is used to build a double difference model of pseudorange based on a pseudorange measurement equation according to a complete deception state and a partial truth state; a double difference model of carrier phase is built based on a carrier phase measurement equation according to a complete deception state and a partial truth state; The final double-difference model module is formed to integrate the double-difference model of pseudorange and the double-difference model of carrier phase to form the final double-difference model. The final double-difference model represents the relationship between the double-difference measurement value and time, including fixed offset, slope coefficient and random error. The final double-difference model is used to perform calculations to determine whether the calculation result is 0. If the calculation result is 0, it indicates that deception interference exists. If the calculation result is not 0, it indicates that there is no deception interference.

Images