A method, apparatus and system for detecting electromagnetic interference

Abstract

A method, device and system for detecting electromagnetic interference, wherein the method comprises: obtaining carrier-to-noise ratio (CNR) estimation results of a plurality of GNSS signals; calculating a CNR peak-to-peak value of each GNSS signal according to the obtained CNR estimation results; calculating a CNR fluctuation feature of each GNSS signal according to the obtained CNR estimation results; calculating a similarity of the CNR fluctuation features of any two GNSS signals; and performing interference determination on GNSS signals whose similarity satisfies a preset condition. The embodiment of the present application sets a condition for the similarity of the CNR fluctuation features of GNSS signals to perform interference detection, has the ability to distinguish between suppression interference and deception interference, and can effectively detect all deception interference including retransmission deception interference and generated deception interference. The electromagnetic interference detection system described above can realize GNSS electromagnetic interference detection using a single-element antenna, thereby reducing the size, power consumption and weight of the detection system, and being more suitable for unmanned aerial vehicle application scenarios.

Description

Technical Field

[0001] This invention relates to, but is not limited to, satellite navigation technology, and particularly to a method, apparatus, and system for detecting electromagnetic interference. Background Technology

[0002] Electromagnetic interference (EMI) detection and elimination has always been a hot and challenging issue in Global Navigation Satellite System (GNSS) applications. Electromagnetic interference can be categorized into suppression jamming and deception jamming. Deception jamming produces waveforms identical or similar to the real signals transmitted by navigation satellites, with low transmission power and high concealment. It can trick GNSS receivers into acquiring and tracking it, leading to incorrect positioning and timing results. Its harmfulness is generally greater than suppression jamming. Deception jamming can be further subdivided into generative deception and relay deception. The former mainly uses jammers to simulate the transmission of real satellite signals, while the latter mainly achieves this by receiving and relaying real satellite signals.

[0003] GNSS has wide applications in the aviation field. With the rapid growth of the drone market, it is predicted that by 2025, the drone market size will exceed $50 billion, and the number of GNSS receivers installed on drones will reach 70 million. Aviation applications, represented by drones, have extremely high requirements for the accuracy and integrity of GNSS positioning. When the GNSS positioning device on a drone is spoofed, it can lead to the drone making an emergency landing or even crashing. Therefore, detecting spoofing interference is of great significance.

[0004] Among the related technologies, there are two methods for detecting deception interference. One is based on array antennas, which estimates the signal incident direction and identifies signals with the same incident direction as deception interference. However, this technology requires array antennas, which are large, consume a lot of power, and are heavy, making them unsuitable for applications such as drones. The other method uses a single-element antenna and detects deception interference based on signal power or signal arrival time. However, the signal power-based detection method cannot distinguish between suppression interference and deception interference, while the signal arrival time-based detection method is effective against repeater-type deception but not against generative deception. Summary of the Invention

[0005] In view of this, the embodiments of the present invention provide the following solutions.

[0006] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0007] This invention provides a method for detecting electromagnetic interference, comprising:

[0008] Among multiple GNSS signals, for each GNSS signal, the peak-to-peak value of the GNSS signal's carrier-to-noise ratio (CNR) is calculated based on the CNR estimation results; the CNR fluctuation characteristics of the GNSS signal are also calculated based on the CNR estimation results.

[0009] Calculate the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals among the plurality of GNSS signals;

[0010] Interference determination is performed on GNSS signals whose similarity meets preset conditions.

[0011] In one exemplary instance, calculating the peak-to-peak value of the carrier-to-noise ratio (CNR) of the GNSS signal based on the CNR estimation result includes:

[0012] The peak-to-peak carrier-to-noise ratio of each GNSS signal is calculated using the following formula:

[0013]

[0014] Among them, there are M GNSS signals, and the carrier-to-noise ratio estimation result of the m-th GNSS signal is R. m (n), where m ranges from 1 to M, and n is a time series, ranging from 1 to 36, with the unit being seconds; This indicates that the sequence f(n) is traversed n and the maximum value is obtained. P represents iterating through n and finding the minimum value of the sequence f(n); m The peak-to-peak carrier-to-noise ratio is expressed in dB.

[0015] In one exemplary instance, calculating the carrier-to-noise ratio (CNR) fluctuation characteristics of the GNSS signal based on the CNR estimation results includes:

[0016] The carrier-to-noise ratio fluctuation characteristics of each GNSS signal are calculated using the following formula:

[0017]

[0018] Among them, there are M GNSS signals, and the carrier-to-noise ratio estimation result of the m-th GNSS signal is R. m (n), where m ranges from 1 to M, and n is a time series, ranging from 1 to 36, with the unit being seconds; This represents iterating through n and taking the maximum value of the sequence f(n), where N is 36; ΔR m (n) represents the carrier-to-noise ratio fluctuation characteristic, in dB.

[0019] In one exemplary instance, calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals among the plurality of GNSS signals includes:

[0020] The similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals is calculated using the following formula:

[0021]

[0022] Among them, two GNSS signals are randomly selected from M GNSS signals, denoted as k and l, where the values ​​of k and l range from 1 to M, and ΔR k (n) represents the carrier-to-noise ratio fluctuation characteristic of the k-th GNSS signal, ΔR l (n) Carrier-to-noise ratio fluctuation characteristics of the l-th GNSS signal; T kl The similarity of the carrier-to-noise ratio fluctuation characteristics of the k-th and l-th GNSS signals is given by N, which is 36.

[0023] In one exemplary instance, the interference determination of GNSS signals whose similarity meets preset conditions includes:

[0024] Among multiple GNSS signals, if only some GNSS signals satisfy T kl ≤Th, and in the order of peak-to-peak carrier-to-noise ratio (PNR) of all GNSS signals from largest to smallest, P k and P l If it belongs to the top 50%, it is judged as deception and interference;

[0025] In multiple GNSS signals, if all GNSS signals satisfy T kl If ≤Th, it is determined to be a suppressed interference;

[0026] Among them, T kl Let Th be the similarity of the carrier-to-noise ratio fluctuation characteristics of the k-th and l-th GNSS signals, and let P be the similarity threshold. k Let P be the peak-to-peak carrier-to-noise ratio of the k-th GNSS signal. l denoted as the peak-to-peak carrier-to-noise ratio of the l-th GNSS signal.

[0027] This invention also provides an electromagnetic interference detection device, comprising:

[0028] The first module is used to calculate the peak-to-peak value of the carrier-to-noise ratio of a GNSS signal for each GNSS signal based on the carrier-to-noise ratio estimation results.

[0029] The second module is used to calculate the carrier-to-noise ratio fluctuation characteristics of the GNSS signal based on the carrier-to-noise ratio estimation results.

[0030] The calculation module is used to calculate the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals among the plurality of GNSS signals;

[0031] The judgment module is used to determine interference for GNSS signals whose similarity meets preset conditions.

[0032] This invention also provides an electromagnetic interference detection device, including a processor and a computer-readable storage medium, wherein the computer-readable storage medium stores instructions, and when the instructions are executed by the processor, the electromagnetic interference detection method described above is implemented.

[0033] This invention also provides an electromagnetic interference detection system, comprising:

[0034] The antenna is configured to receive electromagnetic waves emitted by GNSS navigation satellites, convert the received electromagnetic waves into right-hand circularly polarized electrical signals and left-hand circularly polarized electrical signals, and combine the right-hand circularly polarized electrical signals with the left-hand circularly polarized electrical signals after phase shifting to output GNSS signals.

[0035] A GNSS receiver is configured to receive the GNSS signal output by the antenna, acquire, track, and estimate the carrier-to-noise ratio of the GNSS signal, and output the carrier-to-noise ratio estimation result of the GNSS signal.

[0036] An electromagnetic interference detection device includes: a first module for calculating the peak-to-peak value of the carrier-to-noise ratio (CNR) of a GNSS signal for each GNSS signal based on the CNR estimation result; a second module for calculating the CNR fluctuation characteristics of the GNSS signal based on the CNR estimation result; a calculation module for calculating the similarity of the CNR fluctuation characteristics of any two GNSS signals among the multiple GNSS signals; and a determination module for determining interference in GNSS signals whose similarity meets a preset condition.

[0037] In one exemplary instance, the antenna is a single-element dual-polarized antenna.

[0038] In one exemplary instance, the phase shifting of the right-hand circularly polarized electrical signal includes:

[0039] The right-hand circularly polarized electrical signal is periodically phase-shifted between 0 and 360°.

[0040] The aforementioned electromagnetic interference detection method, apparatus, and system include the following detection method: acquiring carrier-to-noise ratio (CNR) estimation results for multiple GNSS signals; calculating the peak-to-peak CNR value of each GNSS signal based on the acquired CNR estimation results; calculating the CNR fluctuation characteristics of each GNSS signal based on the acquired CNR estimation results; calculating the similarity of the CNR fluctuation characteristics of any two GNSS signals based on the CNR fluctuation characteristics; and determining interference for GNSS signals whose similarity meets preset conditions. This invention, by setting conditions for the similarity of the CNR fluctuation characteristics of GNSS signals to perform interference detection, has the ability to distinguish between suppression interference and deception interference, and can effectively detect all deception interference, including repeater-type deception interference and generator-type deception interference. The aforementioned electromagnetic interference detection system can achieve GNSS electromagnetic interference detection using a single-element antenna, reducing the size, power consumption, and weight of the detection system, making it more suitable for UAV application scenarios.

[0041] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0042] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0043] Figure 1 This is a schematic diagram of an electromagnetic interference detection method according to an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of an electromagnetic interference detection device according to an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of an electromagnetic interference detection system according to an embodiment of the present invention. Detailed Implementation

[0046] This invention describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0047] This invention includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this invention can also be combined with any conventional features or elements to form a unique inventive scheme as defined by the claims. Any feature or element of any embodiment can also be combined with features or elements from other inventive schemes to form another unique inventive scheme as defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this invention can be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims.

[0048] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims relating to the method and / or process should not be limited to the steps performed in the order written, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of the invention.

[0049] This invention provides a method for detecting electromagnetic interference, such as... Figure 1 As shown, it includes:

[0050] Step 101: Among multiple GNSS signals, for each GNSS signal, calculate the peak-to-peak value of the carrier-to-noise ratio of the GNSS signal based on the carrier-to-noise ratio estimation results of the GNSS signal.

[0051] Step 102: Calculate the carrier-to-noise ratio fluctuation characteristics of the GNSS signal based on the carrier-to-noise ratio estimation results;

[0052] Step 103: Calculate the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals among multiple GNSS signals;

[0053] Step 104: Perform interference determination on GNSS signals whose similarity meets the preset conditions.

[0054] In one exemplary instance, the above-described steps 101 to 104 can be performed by digital logic devices with digital signal processing and storage functions, such as programmable logic devices, digital signal processors, and application-specific integrated circuits.

[0055] In one exemplary instance, step 101, for each of the multiple GNSS signals, calculates the peak-to-peak value of the carrier-to-noise ratio (CNR) of the GNSS signal based on the CNR estimation result of the GNSS signal, including:

[0056] The peak-to-peak carrier-to-noise ratio (CNR) of each GNSS signal is calculated using the following formula:

[0057]

[0058] Among them, there are M GNSS signals, and the carrier-to-noise ratio estimation result of the m-th GNSS signal is R. m (n), where m ranges from 1 to M, and n is a time series, ranging from 1 to 36, with the unit being seconds; This indicates that the sequence f(n) is traversed n and the maximum value is obtained. P represents iterating through n and finding the minimum value of the sequence f(n); m The peak-to-peak carrier-to-noise ratio is expressed in dB.

[0059] In one exemplary instance, step 102, calculating the carrier-to-noise ratio (CNR) fluctuation characteristics of the GNSS signal based on the CNR estimation results, includes:

[0060] The carrier-to-noise ratio fluctuation characteristics of each GNSS signal are calculated using the following formula:

[0061]

[0062] Among them, there are M GNSS signals, and the carrier-to-noise ratio estimation result of the m-th GNSS signal is R. m (n), where m ranges from 1 to M, and n is a time series, ranging from 1 to 36, with the unit being seconds; This represents iterating through n and taking the maximum value of the sequence f(n), where N is 36; ΔR m (n) represents the carrier-to-noise ratio fluctuation characteristic, in dB.

[0063] In one exemplary instance, step 103, calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals among a plurality of GNSS signals, includes:

[0064] The similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals is calculated using the following formula:

[0065]

[0066] Among them, two GNSS signals are randomly selected from M GNSS signals (totaling M GNSS signals). (A combination of these combinations), denoted as k and l, where the values ​​of k and l range from 1 to M, ΔR k (n) represents the carrier-to-noise ratio fluctuation characteristic of the k-th GNSS signal, ΔR l (n) Carrier-to-noise ratio fluctuation characteristics of the l-th GNSS signal; T kl The similarity of the carrier-to-noise ratio fluctuation characteristics between the k-th and l-th GNSS signals is given by N, which is 36. kl The smaller the value, the higher the similarity of the carrier-to-noise ratio fluctuation characteristics of the two GNSS signals.

[0067] In one exemplary instance, step 104, which involves determining interference for GNSS signals whose similarity meets preset conditions, includes:

[0068] Among multiple GNSS signals, if only some GNSS signals satisfy T kl ≤Th, and in the order of peak-to-peak carrier-to-noise ratio (PNR) of all GNSS signals from largest to smallest, P k and P l If it belongs to the top 50%, it is judged as deception and interference;

[0069] In multiple GNSS signals, if all GNSS signals satisfy T kl If ≤Th, it is determined to be a suppressed interference;

[0070] Among them, T kl Let Th be the similarity of the carrier-to-noise ratio fluctuation characteristics of the k-th and l-th GNSS signals, and let P be the similarity threshold. k Let P be the peak-to-peak carrier-to-noise ratio of the k-th GNSS signal. l denoted as the peak-to-peak carrier-to-noise ratio of the l-th GNSS signal.

[0071] In one exemplary instance, the value of Th depends on the required false alarm probability, for example, an empirical value of 1.2.

[0072] Under suppression interference, the carrier-to-noise ratio (CNR) of all GNSS signals exhibits periodic fluctuations, while under deception interference, only the CNR of the deceived GNSS signal exhibits periodic fluctuations. Therefore, this embodiment of the invention, by setting conditions for the similarity of the CNR fluctuation characteristics of GNSS signals to perform interference detection, has the ability to distinguish between suppression interference and deception interference, and can effectively detect all deception interference, including forwarding deception interference and generative deception interference.

[0073] On the other hand, embodiments of the present invention also provide an electromagnetic interference detection device, such as... Figure 2 As shown, it includes:

[0074] The first processing module is used to calculate the peak-to-peak value of the carrier-to-noise ratio of a GNSS signal for each GNSS signal based on the carrier-to-noise ratio estimation result of the GNSS signal among multiple GNSS signals.

[0075] The second processing module is used to calculate the carrier-to-noise ratio fluctuation characteristics of the GNSS signal based on the carrier-to-noise ratio estimation results of the GNSS signal.

[0076] The calculation module is used to calculate the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals among multiple GNSS signals;

[0077] The judgment module is used to determine interference for GNSS signals whose similarity meets preset conditions.

[0078] On the other hand, embodiments of the present invention also provide an electromagnetic interference detection device, including a processor and a computer-readable storage medium, wherein the computer-readable storage medium stores instructions, and when the instructions are executed by the processor, the above-described electromagnetic interference detection method is implemented.

[0079] On the other hand, embodiments of the present invention also provide an electromagnetic interference detection system, such as... Figure 3 As shown, it includes:

[0080] The antenna is configured to receive electromagnetic waves emitted by GNSS navigation satellites, convert the received electromagnetic waves into right-hand circularly polarized electrical signals and left-hand circularly polarized electrical signals, and combine the right-hand circularly polarized electrical signals with the left-hand circularly polarized electrical signals after phase shifting to output GNSS signals.

[0081] A GNSS receiver is configured to receive GNSS signals output from an antenna, acquire, track, and estimate the carrier-to-noise ratio (CNR) of the GNSS signals, and output the CNR estimation results of the GNSS signals.

[0082] An electromagnetic interference detection device includes: a first processing module for calculating the peak-to-peak value of the carrier-to-noise ratio (CNR) of a GNSS signal for each GNSS signal based on the CNR estimation result; a second processing module for calculating the CNR fluctuation characteristics of the GNSS signal based on the CNR estimation result; a calculation module for calculating the similarity of the CNR fluctuation characteristics of any two GNSS signals among the multiple GNSS signals; and a judgment module for judging interference in GNSS signals whose similarity meets a preset condition.

[0083] The function of a GNSS antenna is to convert the electromagnetic waves emitted by navigation satellites into electrical signals (current or voltage). The electromagnetic waves emitted by navigation satellites are right-hand circularly polarized (RHCP), and to improve reception efficiency, GNSS antennas are generally designed as right-hand circularly polarized antennas. However, due to design and manufacturing errors, when electromagnetic waves are incident from a high elevation angle (assuming an elevation angle of 90 degrees in the zenith direction), while the GNSS antenna converts most of the electromagnetic wave energy into a right-hand circularly polarized electrical signal, it also converts a small portion of the electromagnetic wave energy into a left-hand circularly polarized (LHCP) electrical signal. Furthermore, as the elevation angle decreases, the proportion of energy in the converted left-hand circularly polarized electrical signal increases. At a 0-degree elevation angle, the energy of the converted left-hand circularly polarized electrical signal is approximately the same as that of the right-hand circularly polarized electrical signal.

[0084] In one exemplary instance, for drone applications, electromagnetic interference typically originates from low or negative elevation angles. Therefore, a single-element dual-polarized antenna (capable of simultaneously receiving right-hand circularly polarized and left-hand circularly polarized electrical signals) can be used to create a null in the low elevation angle direction. In another exemplary instance, the right-hand circularly polarized electrical signal is periodically phase-shifted between 0° and 360°.

[0085] In one exemplary instance, the total output x(t) of a single-element dual-polarized antenna is:

[0086]

[0087] Where, x R (t) represents the right-hand circularly polarized (RHCR) signal output by a single-element dual-polarized antenna, x L (t) represents the left-hand circularly polarized (LHCR) signal output by a single-element dual-polarized antenna. The phase of the programmable phase shifter is expressed in degrees and ranges from 0 to 360°.

[0088] In one exemplary instance, the RHCR signal x output by the single-element dual-polarized antenna is [missing information - likely a signal type or characteristic] in both low elevation and negative elevation directions. R (t) and LHCR signal x L (t) The power is roughly the same, and the phases are correlated. By adjusting the phase of the programmable phase shifter... It can make x such that at a certain azimuth angle φ, R (t) and x L When the phases of x(t) are superimposed in opposite phases, the power of the combined output x(t) is close to 0, meaning that the single-element dual-polarized antenna forms a null in the azimuth angle φ.

[0089] In one exemplary instance, a programmable phase shifter is used to phase-shift a right-hand circularly polarized (RHCR) signal and combine it with a left-hand circularly polarized (LHCR) signal.

[0090] In one exemplary instance, the phase of the programmable phase shifter is periodically adjusted. The phase of the programmable phase shifter is adjusted as follows: the initial value is 0, the step is 10°, and it is periodically adjusted between 0 and 360°. The dwell time of each phase value is 1 second, that is, the total adjustment cycle takes 36 seconds.

[0091] In one exemplary instance, the conversion of the received electromagnetic waves into RHCR and LHCR electrical signals is achieved by a metal patch and dielectric and a 90° coupler, the phase shifting is achieved by a programmable phase shifter, and the combining is achieved by a power combiner.

[0092] In one exemplary instance, the carrier-to-noise ratio estimate of the GNSS signal output by the GNSS receiver is output at a frequency of 1 Hz, that is, once per second, in dBHz.

[0093] When a dual-polarized antenna performs a null periodic scan, if it is a suppression jamming attack, the carrier-to-noise ratio (CNR) of all GNSS signals will fluctuate periodically (the CNR is at its maximum when the null is aligned with the suppression jamming attack); however, if it is a spoofing jamming attack, only the CNR of the spoofed GNSS signal will fluctuate periodically (the CNR of the spoofed GNSS signal decreases when the null is aligned with the spoofing jamming attack, while the CNR of the unspoofed GNSS signal remains unchanged).

[0094] The aforementioned electromagnetic interference detection method, apparatus, and system include the following detection method: acquiring carrier-to-noise ratio (CNR) estimation results for multiple GNSS signals; calculating the peak-to-peak CNR value of each GNSS signal based on the acquired CNR estimation results; calculating the CNR fluctuation characteristics of each GNSS signal based on the acquired CNR estimation results; calculating the similarity of the CNR fluctuation characteristics of any two GNSS signals based on the CNR fluctuation characteristics; and determining interference for GNSS signals whose similarity meets preset conditions. This invention, by setting conditions for the similarity of the CNR fluctuation characteristics of GNSS signals to perform interference detection, has the ability to distinguish between suppression interference and deception interference, and can effectively detect all deception interference, including repeater-type deception interference and generator-type deception interference. The aforementioned electromagnetic interference detection system can achieve GNSS electromagnetic interference detection using a single-element antenna, reducing the size, power consumption, and weight of the detection system, making it more suitable for UAV application scenarios.

[0095] It will be understood by those skilled in the art that all or some of the steps, systems, or apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

Claims

1. A method for detecting electromagnetic interference, comprising: Among multiple GNSS signals, for each GNSS signal, the peak-to-peak value of the GNSS signal is calculated based on the carrier-to-noise ratio estimation results; The carrier-to-noise ratio (CNR) fluctuation characteristics of GNSS signals are calculated based on the CNR estimation results. Calculate the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals among the plurality of GNSS signals; Interference determination is performed on GNSS signals whose similarity meets preset conditions; The interference determination of GNSS signals whose similarity meets preset conditions includes: Among multiple GNSS signals, if only some GNSS signals satisfy... Furthermore, in the order of peak-to-peak carrier-to-noise ratio (CNR) of all GNSS signals from largest to smallest, and If it belongs to the top 50%, it is judged as deception and interference; Among multiple GNSS signals, if all GNSS signals satisfy... If so, it is determined to be a suppression interference; in, For the first k The and the first l The similarity of the carrier-to-noise ratio fluctuation characteristics of several GNSS signals The similarity threshold is set as follows: For the first k Peak-to-peak carrier-to-noise ratio of a GNSS signal For the first l Peak-to-peak carrier-to-noise ratio of a GNSS signal.

2. The electromagnetic interference detection method according to claim 1, wherein, The calculation of the peak-to-peak value of the carrier-to-noise ratio (CNR) of the GNSS signal based on the CNR estimation results includes: The peak-to-peak carrier-to-noise ratio of each GNSS signal is calculated using the following formula: ； Among them, there are M GNSS signals, and the carrier-to-noise ratio estimation result of the m-th GNSS signal is: The value of m ranges from 1 to M, and n is a time series, with the value of n ranging from 1 to 36, in seconds. This indicates traversing n and taking the sequence. The maximum value, This indicates traversing n and taking the sequence. The minimum value; The peak-to-peak carrier-to-noise ratio is expressed in dB.

3. The method for detecting electromagnetic interference according to claim 1, wherein, The calculation of the carrier-to-noise ratio (CNR) fluctuation characteristics of the GNSS signal based on the CNR estimation results includes: The carrier-to-noise ratio fluctuation characteristics of each GNSS signal are calculated using the following formula: ； Among them, there are M GNSS signals, and the carrier-to-noise ratio estimation result of the m-th GNSS signal is: The value of m ranges from 1 to M, and n is a time series, with the value of n ranging from 1 to 36, in seconds. This indicates traversing n and taking the sequence. The maximum value of N is 36. The carrier-to-noise ratio fluctuation characteristic is expressed in dB.

4. The method for detecting electromagnetic interference according to any one of claims 1-3, wherein, The calculation of the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals among the plurality of GNSS signals includes: The similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals is calculated using the following formula: ； Among them, two GNSS signals are randomly selected from M GNSS signals, and denoted as . k , l , k , l The value range is 1 to M. For the first k Carrier-to-noise ratio fluctuation characteristics of individual GNSS signals No. l Carrier-to-noise ratio fluctuation characteristics of individual GNSS signals; For the first k The and the first l The similarity of the carrier-to-noise ratio fluctuation characteristics of several GNSS signals, where N is 36.

5. An electromagnetic interference detection device, comprising: The first module is used to calculate the peak-to-peak value of the carrier-to-noise ratio of a GNSS signal for each GNSS signal based on the carrier-to-noise ratio estimation results. The second module is used to calculate the carrier-to-noise ratio fluctuation characteristics of the GNSS signal based on the carrier-to-noise ratio estimation results. The calculation module is used to calculate the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals among the plurality of GNSS signals; The judgment module is used to determine interference for GNSS signals whose similarity meets preset conditions. The interference determination of GNSS signals whose similarity meets preset conditions includes: Among multiple GNSS signals, if only some GNSS signals satisfy... Furthermore, in the order of peak-to-peak carrier-to-noise ratio (CNR) of all GNSS signals from largest to smallest, and If it belongs to the top 50%, it is judged as deception and interference; Among multiple GNSS signals, if all GNSS signals satisfy... If so, it is determined to be a suppression interference; in, For the first k The and the first l The similarity of the carrier-to-noise ratio fluctuation characteristics of several GNSS signals The similarity threshold is set as follows: For the first k Peak-to-peak carrier-to-noise ratio of a GNSS signal For the first l Peak-to-peak carrier-to-noise ratio of a GNSS signal.

6. An electromagnetic interference detection device, comprising a processor and a computer-readable storage medium, wherein the computer-readable storage medium stores instructions that, when executed by the processor, implement the electromagnetic interference detection method as described in any one of claims 1 to 4.

7. An electromagnetic interference detection system, comprising: The antenna is configured to receive electromagnetic waves emitted by GNSS navigation satellites, convert the received electromagnetic waves into right-hand circularly polarized electrical signals and left-hand circularly polarized electrical signals, and combine the right-hand circularly polarized electrical signals with the left-hand circularly polarized electrical signals after phase shifting to output GNSS signals. A GNSS receiver is configured to receive the GNSS signal output by the antenna, acquire, track, and estimate the carrier-to-noise ratio of the GNSS signal, and output the carrier-to-noise ratio estimation result of the GNSS signal. An electromagnetic interference detection device includes: a first module for calculating the peak-to-peak carrier noise ratio (CNR) of a GNSS signal for each GNSS signal based on the CNR estimation result; a second module for calculating the CNR fluctuation characteristics of a GNSS signal based on the CNR estimation result; a calculation module for calculating the similarity of the CNR fluctuation characteristics of any two GNSS signals among the multiple GNSS signals; and a determination module for determining interference in GNSS signals whose similarity meets a preset condition. The interference determination of GNSS signals whose similarity meets preset conditions includes: Among multiple GNSS signals, if only some GNSS signals satisfy... Furthermore, in the order of peak-to-peak carrier-to-noise ratio (CNR) of all GNSS signals from largest to smallest, and If it belongs to the top 50%, it is judged as deception and interference; Among multiple GNSS signals, if all GNSS signals satisfy... If so, it is determined to be a suppression interference; in, For the first k The and the first l The similarity of the carrier-to-noise ratio fluctuation characteristics of several GNSS signals The similarity threshold is set as follows: For the first k Peak-to-peak carrier-to-noise ratio of a GNSS signal For the first l Peak-to-peak carrier-to-noise ratio of a GNSS signal.

8. The electromagnetic interference detection system according to claim 7, wherein, The antenna is a single-element dual-polarized antenna.

9. The electromagnetic interference detection system according to claim 7 or 8, wherein, The phase shifting of the right-hand circularly polarized electrical signal includes: The right-hand circularly polarized electrical signal is periodically phase-shifted between 0 and 360°.

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