CN115469338A - Method, device and system for detecting electromagnetic interference - Google Patents
Method, device and system for detecting electromagnetic interference Download PDFInfo
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- CN115469338A CN115469338A CN202211116877.8A CN202211116877A CN115469338A CN 115469338 A CN115469338 A CN 115469338A CN 202211116877 A CN202211116877 A CN 202211116877A CN 115469338 A CN115469338 A CN 115469338A
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Abstract
A method, a device and a system for detecting electromagnetic interference are provided, wherein the detection method comprises the following steps: acquiring carrier-to-noise ratio estimation results of a plurality of GNSS signals, and calculating the carrier-to-noise ratio peak-to-peak value of each GNSS signal according to the acquired carrier-to-noise ratio estimation results; calculating the carrier-to-noise ratio fluctuation characteristic of each GNSS signal according to the obtained carrier-to-noise ratio estimation result; calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals according to the carrier-to-noise ratio fluctuation characteristics; and carrying out interference judgment on the GNSS signals with the similarity meeting the preset conditions. The embodiment of the invention sets conditions for the similarity of carrier-to-noise ratio fluctuation characteristics of GNSS signals to detect the interference, has the capability of distinguishing and suppressing interference and deception interference, and can effectively detect all deception interferences including forwarding type deception interference and generating type deception interference. Above-mentioned electromagnetic interference's detecting system adopts the single-element antenna can realize GNSS electromagnetic interference's detection, has reduced detecting system's size, consumption and weight, more is fit for unmanned aerial vehicle application scenario.
Description
Technical Field
The present invention relates to, but not limited to, satellite navigation technologies, and in particular, to a method, an apparatus, and a system for detecting electromagnetic interference.
Background
The detection and elimination of electromagnetic interference has been a hotspot and difficult problem in Global Navigation Satellite System (GNSS) applications. Electromagnetic interference can be classified into jamming interference and spoofing interference in terms of type. The deception jamming has a waveform which is the same as or similar to a real signal transmitted by a navigation satellite, has small transmission power and strong concealment, can deceive a GNSS receiving terminal to capture and track the deception jamming, and therefore the GNSS receiving terminal can output an incorrect positioning time service result, and the deception jamming is generally more harmful than the suppression jamming. Spoofing interference can be further subdivided into generative spoofing, which simulates the transmission of a real satellite signal primarily through a jammer, and transponder spoofing, which is implemented primarily by receiving and retransmitting a real satellite signal.
GNSS has wide application in the field of aviation. With the rapid growth of the drone market, it is predicted that by 2025, the drone market will scale over $ 500 million and GNSS receivers installed on drones will reach 7000 million. The accuracy and integrity requirements of the aviation application represented by the unmanned aerial vehicle on GNSS positioning are extremely high, when the GNSS positioning device on the unmanned aerial vehicle is deceived, the unmanned aerial vehicle can be caused to forcedly land or even crash, and therefore the detection significance on deceived interference is great.
In the related art, two deception jamming detection methods are included, one is deception jamming detection based on an array antenna, and the method estimates the signal incidence direction and judges the signals with the same incidence direction as deception jamming. However, the implementation of the technology needs to adopt an array antenna, which has large size, high power consumption and heavy weight, and is not suitable for application scenarios such as unmanned aerial vehicles. The other method is to adopt a single-element antenna to perform deception jamming detection through signal power or signal arrival time, wherein the detection method based on the signal power cannot distinguish suppression jamming and deception jamming, but the detection method based on the signal arrival time is effective to forward deception, and the detection effect of generative deception is poor.
Disclosure of Invention
In view of this, the embodiments of the present invention provide the following solutions.
The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.
The embodiment of the invention provides a method for detecting electromagnetic interference, which comprises the following steps:
calculating a carrier-to-noise ratio peak-to-peak value of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal aiming at each GNSS signal in the plurality of GNSS signals; calculating the carrier-to-noise ratio fluctuation characteristic of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal;
calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals;
and performing interference judgment on the GNSS signals with the similarity meeting the preset conditions.
In an exemplary embodiment, the calculating a carrier-to-noise ratio peak-to-peak value of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal includes:
calculating the peak-to-peak carrier-to-noise ratio of each GNSS signal by adopting the following calculation formula:
wherein, the number of GNSS signals is M, and the carrier-to-noise ratio estimation result of the mth GNSS signal is R m (n), wherein the value range of M is 1-M, n is a time sequence, and the value range of n is 1-36 seconds;
representing the traversal of n, taking the maximum value of the sequence f (n),
representing traversal n, and taking the minimum value of the sequence f (n); p is m Is the carrier to noise ratio peak to peak value in dB.
In an exemplary embodiment, the calculating the carrier-to-noise ratio fluctuation characteristic of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal includes:
calculating the carrier-to-noise ratio fluctuation characteristic of each GNSS signal by adopting the following calculation formula:
wherein, the GNSS signalThe number of the GNSS signals is M, and the carrier-to-noise ratio estimation result of the mth GNSS signal is R m (n), wherein the value range of M is 1-M, n is a time sequence, and the value range of n is 1-36 in seconds;
representing traversal N, taking the maximum value of the sequence f (N), wherein the value of N is 36; Δ R m And (n) is the carrier-to-noise ratio fluctuation characteristic and has the unit of dB.
In an exemplary embodiment, the calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals includes:
calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals by adopting the following calculation formula:
wherein, two GNSS signals are arbitrarily selected from the M GNSS signals, k and l are counted, the value range of k and l is 1-M, and delta R k (n) is the carrier-to-noise ratio fluctuation characteristic of the kth GNSS signal, Δ R l (n) a carrier-to-noise ratio fluctuation characteristic of the l-th GNSS signal; t is a unit of kl The value of N is 36, which is the similarity of the carrier-to-noise ratio fluctuation characteristics of the kth GNSS signal and the l-th GNSS signal.
In an exemplary embodiment, the performing interference determination on GNSS signals whose similarity satisfies a preset condition includes:
if only a part of the GNSS signals satisfy T among the plurality of GNSS signals kl Th less, and P in a large to small carrier-to-noise ratio peak-to-peak ranking of all GNSS signals k And P l If the data belongs to the first 50%, the data is judged to be deceptive interference;
in a plurality of GNSS signals, if all the GNSS signals satisfy T kl Judging that the interference is suppressed if the Th is less than or equal to Th;
wherein, T kl Similarity of carrier-to-noise ratio fluctuation characteristics of the kth and the l GNSS signals, th is a similarity judgment threshold, and P is k Carrier to noise ratio peak to peak, P, for the kth GNSS signal l The carrier-to-noise ratio peak-to-peak value of the ith GNSS signal.
An embodiment of the present invention further provides an apparatus for detecting electromagnetic interference, including:
a first module, configured to calculate, for each GNSS signal, a carrier-to-noise ratio peak-to-peak value of the GNSS signal according to a carrier-to-noise ratio estimation result of the GNSS signal in the plurality of GNSS signals;
the second module is used for calculating the carrier-to-noise ratio fluctuation characteristics of the GNSS signals according to the carrier-to-noise ratio estimation results of the GNSS signals;
the calculating module is used for calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals;
and the judging module is used for judging the interference of the GNSS signals with the similarity meeting the preset conditions.
The embodiment of the present invention further provides an apparatus for detecting electromagnetic interference, which includes a processor and a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and when the instructions are executed by the processor, the method for detecting electromagnetic interference is implemented.
An embodiment of the present invention further provides a system for detecting electromagnetic interference, including:
the antenna is used for receiving electromagnetic waves transmitted by a GNSS navigation satellite, converting the received electromagnetic waves into right-hand circularly polarized electric signals and left-hand circularly polarized electric signals, and combining the right-hand circularly polarized electric signals and the left-hand circularly polarized electric signals after phase shifting to output GNSS signals;
the GNSS receiving device is used for receiving the GNSS signals output by the antenna, capturing, tracking and estimating the carrier-to-noise ratio of the GNSS signals and outputting the estimation result of the carrier-to-noise ratio of the GNSS signals;
electromagnetic interference detection apparatus comprising: a first module, configured to calculate, for each GNSS signal, a carrier-to-noise ratio peak-to-peak value of the GNSS signal according to a carrier-to-noise ratio estimation result of the GNSS signal in the plurality of GNSS signals; the second module is used for calculating the carrier-to-noise ratio fluctuation characteristic of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal; the calculating module is used for calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals; and the judging module is used for judging the interference of the GNSS signals with the similarity meeting the preset conditions.
In one illustrative example, the antenna is a single-element dual-polarized antenna.
In one illustrative example, said phase shifting said right hand circularly polarized electrical signal comprises:
and periodically shifting the phase of the right-hand circularly polarized electric signal between 0 and 360 degrees.
The detection method, the device and the system of the electromagnetic interference comprise the following steps: acquiring carrier-to-noise ratio estimation results of a plurality of GNSS signals, and calculating a carrier-to-noise ratio peak-to-peak value of each GNSS signal according to the acquired carrier-to-noise ratio estimation results; calculating the carrier-to-noise ratio fluctuation characteristic of each GNSS signal according to the obtained carrier-to-noise ratio estimation result; calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals according to the carrier-to-noise ratio fluctuation characteristics; and carrying out interference judgment on the GNSS signals with the similarity meeting the preset conditions. The embodiment of the invention sets conditions for the similarity of carrier-to-noise ratio fluctuation characteristics of GNSS signals to detect the interference, has the capability of distinguishing and suppressing interference and deception interference, and can effectively detect all deception interferences including forwarding type deception interference and generating type deception interference. Above-mentioned electromagnetic interference's detecting system adopts the single-array element antenna can realize GNSS electromagnetic interference's detection, has reduced detecting system's size, consumption and weight, more is fit for unmanned aerial vehicle application scene.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and do not constitute a limitation thereof.
FIG. 1 is a schematic diagram of a method for detecting electromagnetic interference according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an apparatus for detecting electromagnetic interference according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of an electromagnetic interference detection system according to an embodiment of the present invention.
Detailed Description
The present invention has been described in terms of several embodiments, but the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the described embodiments of the invention. 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 possible. Any feature or element of any embodiment may be used in combination with or instead of any other feature or element in any other embodiment, unless expressly limited otherwise.
The present invention includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements of the invention that have been disclosed may also be combined with any conventional features or elements to form unique inventive aspects as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive aspects to form yet another unique inventive aspect, as defined by the claims. Thus, it should be understood that any of the features shown and/or discussed in this disclosure may be implemented individually or in any suitable combination. Accordingly, the embodiments are not limited except as by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.
Further, in describing representative embodiments, the specification may have presented the method and/or process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. Other orders of steps are possible as will be understood by those of ordinary skill in the art. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. Furthermore, the claims directed to the method and/or process should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the embodiments of the present invention.
The embodiment of the invention provides a method for detecting electromagnetic interference, which comprises the following steps of:
step 101, calculating a carrier-to-noise ratio peak-to-peak value of a GNSS signal according to a carrier-to-noise ratio estimation result of the GNSS signal for each of a plurality of GNSS signals.
Step 102, calculating the carrier-to-noise ratio fluctuation characteristics of the GNSS signals according to the carrier-to-noise ratio estimation results of the GNSS signals;
103, calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals;
and 104, performing interference judgment on the GNSS signals with the similarity meeting the preset condition.
In an exemplary embodiment, the processes of steps 101 to 104 may be performed by a digital logic device having digital signal operation and storage functions, such as a programmable logic device, a digital signal processor, an application specific integrated circuit, and the like.
In an exemplary embodiment, the step 101 of calculating a carrier-to-noise ratio peak-to-peak value of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal for each GNSS signal in the plurality of GNSS signals includes:
calculating the peak-to-peak carrier-to-noise ratio of each GNSS signal by adopting the following calculation formula:
wherein, the GNSS signals are M, the mth GNSSThe carrier-to-noise ratio of the signal is estimated as R m (n), wherein the value range of M is 1-M, n is a time sequence, and the value range of n is 1-36 seconds;
representing the traversal of n, taking the maximum value of the sequence f (n),
representing the traversal n, and taking the minimum value of the sequence f (n); p m Is the carrier to noise ratio peak to peak value in dB.
In an exemplary embodiment, the step 102 of calculating a carrier-to-noise ratio fluctuation characteristic of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal includes:
and calculating the carrier-to-noise ratio fluctuation characteristic of each GNSS signal by adopting the following calculation formula:
wherein, the number of GNSS signals is M, and the carrier-to-noise ratio estimation result of the mth GNSS signal is R m (n), wherein the value range of M is 1-M, n is a time sequence, and the value range of n is 1-36 seconds;
representing traversal N, taking the maximum value of the sequence f (N), wherein the value of N is 36; Δ R m And (n) is the carrier-to-noise ratio fluctuation characteristic and has the unit of dB.
In an exemplary embodiment, the step 103 of calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals includes:
calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals by adopting the following calculation formula:
wherein two of the M GNSS signals are arbitrarily selectedGNSS signals (common)
Seed combination) is counted as k, l, the value ranges of k and l are 1-M, and delta R k (n) is the carrier-to-noise ratio fluctuation characteristic of the kth GNSS signal, Δ R l (n) a carrier-to-noise ratio fluctuation characteristic of the l-th GNSS signal; t is a unit of kl The value of N is 36, which is the similarity of the carrier-to-noise ratio fluctuation characteristics of the kth GNSS signal and the l-th GNSS signal. T is a unit of kl The smaller the value of (A) is, the higher the similarity of the fluctuation characteristics of the carrier-to-noise ratio of the two GNSS signals is.
In an exemplary embodiment, the interference determination of the GNSS signals with the similarity satisfying the preset condition in step 104 includes:
if only a part of the GNSS signals satisfy T among the plurality of GNSS signals kl Less than or equal to Th, and P is the order of the peak-to-peak values of the carrier-to-noise ratios of all GNSS signals from large to small k And P l If the data belongs to the first 50%, the data is judged to be deception jamming;
in a plurality of GNSS signals, if all the GNSS signals satisfy T kl Judging that the interference is suppressed if the Th is less than or equal to Th;
wherein, T kl Similarity of carrier-to-noise ratio fluctuation characteristics of the kth and the l GNSS signals, th is a similarity judgment threshold, and P is k Is the carrier-to-noise ratio peak-to-peak value, P, of the kth GNSS signal l The carrier-to-noise ratio peak-to-peak value of the ith GNSS signal.
In an exemplary embodiment, the value of Th depends on the required false alarm probability, such as: an empirical value of 1.2 may be taken.
In the interference suppression case, all GNSS signals may have periodic fluctuations in carrier-to-noise ratio, and in the jamming case, only spoofed GNSS signals may have periodic fluctuations in carrier-to-noise ratio. Therefore, the embodiment of the invention sets conditions for the similarity of carrier-to-noise ratio fluctuation characteristics of GNSS signals to detect interference, has the capability of distinguishing suppressed interference and deceptive interference, and can effectively detect all deceptive interferences including forwarding type deceptive interference and generated deceptive interference.
On the other hand, an embodiment of the present invention further provides an apparatus for detecting electromagnetic interference, as shown in fig. 2, including:
the first processing module is used for calculating a carrier-to-noise ratio peak value of the GNSS signal according to a carrier-to-noise ratio estimation result of the GNSS signal aiming at each GNSS signal in the plurality of GNSS signals;
the second processing module is used for calculating the carrier-to-noise ratio fluctuation characteristics of the GNSS signals according to the carrier-to-noise ratio estimation results of the GNSS signals;
the calculating module is used for calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals;
and the judging module is used for judging the interference of the GNSS signals with the similarity meeting the preset conditions.
On the other hand, the embodiment of the present invention further provides an apparatus for detecting electromagnetic interference, which includes a processor and a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and when the instructions are executed by the processor, the method for detecting electromagnetic interference is implemented.
On the other hand, an embodiment of the present invention further provides a system for detecting electromagnetic interference, as shown in fig. 3, including:
the antenna is used for receiving electromagnetic waves transmitted by the GNSS navigation satellite, converting the received electromagnetic waves into right-hand circularly polarized electric signals and left-hand circularly polarized electric signals, and combining the right-hand circularly polarized electric signals and the left-hand circularly polarized electric signals after phase shifting to output GNSS signals;
the GNSS receiving device is arranged for receiving the GNSS signals output by the antenna, capturing, tracking and estimating the carrier-to-noise ratio of the GNSS signals and outputting the estimation result of the carrier-to-noise ratio of the GNSS signals;
electromagnetic interference detection apparatus comprising: the first processing module is used for calculating a carrier-to-noise ratio peak value of the GNSS signal according to a carrier-to-noise ratio estimation result of the GNSS signal aiming at each GNSS signal in the plurality of GNSS signals; the second processing module is used for calculating the carrier-to-noise ratio fluctuation characteristics of the GNSS signals according to the carrier-to-noise ratio estimation results of the GNSS signals; the calculating module is used for calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals; and the judging module is used for judging the interference of the GNSS signals with the similarity meeting the preset conditions.
The function of the GNSS antenna is to convert electromagnetic waves emitted by the navigation satellite into electrical signals (current or voltage), the electromagnetic waves emitted by the navigation satellite are Right Hand Circular Polarized (RHCP), and in order to improve the receiving efficiency, the GNSS antenna is also generally designed as a Right hand circular polarized antenna. However, due to design and manufacturing errors of the antenna, when electromagnetic waves are incident from a high elevation angle (assuming that the elevation angle of the zenith direction is 90 degrees), the GNSS antenna converts most of electromagnetic wave energy into right-hand circularly polarized electrical signals, and also converts a small part of electromagnetic wave energy into Left-hand circularly polarized (LHCP) electrical signals, and as the elevation angle decreases, the energy of the converted Left-hand circularly polarized electrical signals is larger, and in the 0-degree elevation angle direction, the energy of the converted Left-hand circularly polarized electrical signals is almost the same as that of the right-hand circularly polarized electrical signals.
In an exemplary embodiment, for drone applications, the electromagnetic interference is generally from low elevation or negative elevation directions, and therefore nulls may be formed in the low elevation direction using a single-element dual-polarized antenna (which can receive both right-hand and left-hand circularly polarized electrical signals). In one illustrative example, the right hand circularly polarized electrical signal is phase shifted periodically between 0 and 360 °.
In one illustrative example, the total output x (t) of a single-element dual-polarized antenna is:
wherein x is R (t) is a right-hand circularly polarized (RHCR) signal output by the single-element dual-polarized antenna, x L (t) is a left-handed circularly polarized (LHCR) signal output by the single-element dual-polarized antenna,
the unit is the phase of the programmable phase shifter, and the value range is 0-360 degrees.
In aIn the illustrative example, in the low elevation angle and negative elevation angle direction, the RHCR signal x output by the single-element dual-polarized antenna R (t) and LHCR Signal x L (t) power is comparable and phase correlation exists. By adjusting the phase of a programmable phase shifter
Can be made to be at a certain azimuth angle phi, x R (t) and x L And (t) reverse phase superposition, wherein the power of the combined output x (t) is close to 0, namely the single-array element dual-polarized antenna forms a null at the azimuth angle phi.
In one illustrative example, a right hand circularly polarized (RHCR) signal is phase shifted with a programmable phase shifter and combined with a left hand circularly polarized LHCR signal.
In one illustrative example, the phase of a 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 degrees, the adjustment is periodically carried out between 0 and 360 degrees, and the dwell time of each phase value is 1 second, namely 36 seconds when the adjustment is shared by one period.
In one illustrative example, the conversion of the received electromagnetic waves into electrical RHCR signals and electrical LHCR signals is accomplished by a metal patch and dielectric and 90 ° coupler, the phase shifting is accomplished by a programmable phase shifter, and the combining is accomplished by a power combiner.
In an exemplary embodiment, the carrier-to-noise ratio estimate of the GNSS signal output by the GNSS receiver apparatus is output at a frequency of 1Hz, i.e., once per second, in dBHz.
When the dual-polarized antenna is periodically scanned by nulling, if interference suppression is performed, the carrier-to-noise ratios of all GNSS signals generate periodic fluctuation (when the nulling is aligned with the interference suppression, the carrier-to-noise ratio is maximum); if the interference is spoofing interference, only the carrier-to-noise ratio of the spoofed GNSS signal will fluctuate periodically (when the spoofing interference is aligned with the spoofing interference, the carrier-to-noise ratio of the spoofed GNSS signal becomes smaller, and the carrier-to-noise ratio of the spoofed GNSS signal does not change).
The detection method, the device and the system of the electromagnetic interference are characterized in that the detection method comprises the following steps: acquiring carrier-to-noise ratio estimation results of a plurality of GNSS signals, and calculating the carrier-to-noise ratio peak-to-peak value of each GNSS signal according to the acquired carrier-to-noise ratio estimation results; calculating the carrier-to-noise ratio fluctuation characteristic of each GNSS signal according to the obtained carrier-to-noise ratio estimation result; calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals according to the carrier-to-noise ratio fluctuation characteristics; and carrying out interference judgment on the GNSS signals with the similarity meeting the preset conditions. The embodiment of the invention sets the conditions for the similarity of the carrier-to-noise ratio fluctuation characteristics of the GNSS signals to carry out interference detection, has the capability of distinguishing and suppressing interference and deception interference, and can effectively detect all deception interferences including forwarding type deception interference and generating type deception interference. Above-mentioned electromagnetic interference's detecting system adopts the single-element antenna can realize GNSS electromagnetic interference's detection, has reduced detecting system's size, consumption and weight, more is fit for unmanned aerial vehicle application scenario.
It will be understood by those of ordinary skill in the art that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the 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. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.
Claims (10)
1. A method of detecting electromagnetic interference, comprising:
calculating a carrier-to-noise ratio peak-to-peak value of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal aiming at each GNSS signal in the plurality of GNSS signals;
calculating the carrier-to-noise ratio fluctuation characteristic of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal;
calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals;
and performing interference judgment on the GNSS signals with the similarity meeting the preset conditions.
2. The method for detecting electromagnetic interference according to claim 1,
the calculating of the carrier-to-noise ratio peak-to-peak value of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal includes:
calculating the peak-to-peak carrier-to-noise ratio of each GNSS signal by adopting the following calculation formula:
wherein, the number of GNSS signals is M, and the carrier-to-noise ratio estimation result of the mth GNSS signal is R m (n), wherein the value range of M is 1-M, n is a time sequence, and the value range of n is 1-36 in seconds;
representing the traversal of n, taking the maximum value of the sequence f (n),
representing traversal n, and taking the minimum value of the sequence f (n); p m Is the carrier to noise ratio peak to peak value in dB.
3. The method for detecting electromagnetic interference according to claim 1,
the calculating of the carrier-to-noise ratio fluctuation characteristic of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal includes:
calculating the carrier-to-noise ratio fluctuation characteristic of each GNSS signal by adopting the following calculation formula:
wherein, the GNSS signals are M, the carrier-to-noise ratio estimation result of the mth GNSS signal is R m (n), wherein the value range of M is 1-M, n is a time sequence, and the value range of n is 1-36 in seconds;
representing traversal N, taking the maximum value of the sequence f (N), wherein the value of N is 36; Δ R m And (n) is the carrier-to-noise ratio fluctuation characteristic and has the unit of dB.
4. The method for detecting electromagnetic interference according to any one of claims 1 to 3,
the calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals includes:
calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals by adopting the following calculation formula:
wherein, two GNSS signals are arbitrarily selected from the M GNSS signals, k and l are counted, the value range of k and l is 1-M, and delta R k (n) is the carrier-to-noise ratio fluctuation characteristic of the kth GNSS signal, Δ R l (n) a carrier-to-noise ratio fluctuation characteristic of the l-th GNSS signal; t is kl The value of N is 36, which is the similarity of the carrier-to-noise ratio fluctuation characteristics of the kth GNSS signal and the l-th GNSS signal.
5. The method for detecting electromagnetic interference according to claim 4,
the interference judgment of the GNSS signals with the similarity meeting the preset conditions comprises the following steps:
if only a part of the GNSS signals satisfy T among the plurality of GNSS signals kl Less than or equal to Th, and P is the order of the peak-to-peak values of the carrier-to-noise ratios of all GNSS signals from large to small k And P l If the data belongs to the first 50%, the data is judged to be deceptive interference;
in a plurality of GNSS signals, if all the GNSS signals satisfy T kl Judging that the interference is suppressed if the Th is less than or equal to Th;
wherein, T kl The similarity of the carrier-to-noise ratio fluctuation characteristics of the kth GNSS signal and the l GNSS signal, th is a similarity judgment threshold, and P is k Carrier to noise ratio peak to peak, P, for the kth GNSS signal l The carrier-to-noise ratio peak-to-peak value of the ith GNSS signal.
6. An apparatus for detecting electromagnetic interference, comprising:
the first module is used for calculating a carrier-to-noise ratio peak-to-peak value of the GNSS signal according to a carrier-to-noise ratio estimation result of the GNSS signal aiming at each GNSS signal in a plurality of GNSS signals;
the second module is used for calculating the carrier-to-noise ratio fluctuation characteristic of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal;
the calculating module is used for calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals;
and the judging module is used for judging the interference of the GNSS signals with the similarity meeting the preset conditions.
7. An apparatus for detecting electromagnetic interference, comprising a processor and a computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium, and when the instructions are executed by the processor, the method for detecting electromagnetic interference according to any one of claims 1 to 5 is implemented.
8. A system for detecting electromagnetic interference, comprising:
the antenna is used for receiving electromagnetic waves transmitted by a GNSS navigation satellite, converting the received electromagnetic waves into right-hand circularly polarized electric signals and left-hand circularly polarized electric signals, and combining the right-hand circularly polarized electric signals and the left-hand circularly polarized electric signals after phase shifting to output GNSS signals;
the GNSS receiving device is used for receiving the GNSS signals output by the antenna, capturing, tracking and estimating the carrier-to-noise ratio of the GNSS signals and outputting the estimation result of the carrier-to-noise ratio of the GNSS signals;
electromagnetic interference detection apparatus comprising: the first module is used for calculating a carrier-to-noise ratio peak-to-peak value of the GNSS signal according to a carrier-to-noise ratio estimation result of the GNSS signal aiming at each GNSS signal in a plurality of GNSS signals; the second module is used for calculating the carrier-to-noise ratio fluctuation characteristic of the GNSS signal according to the carrier-to-noise ratio estimation result of the GNSS signal; the calculating module is used for calculating the similarity of the carrier-to-noise ratio fluctuation characteristics of any two GNSS signals in the plurality of GNSS signals; and the judging module is used for judging the interference of the GNSS signals with the similarity meeting the preset conditions.
9. The system for detecting electromagnetic interference according to claim 8,
the antenna is a single-array element dual-polarized antenna.
10. The system for detecting electromagnetic interference according to claim 8 or 9,
the phase shift of the right-hand circularly polarized electric signal comprises the following steps:
and periodically shifting the phase of the right-hand circularly polarized electric signal between 0 and 360 degrees.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116794691A (en) * | 2023-08-25 | 2023-09-22 | 长沙金维信息技术有限公司 | Navigation signal capturing system and method |
| CN117492036A (en) * | 2023-11-03 | 2024-02-02 | 河南省科学院应用物理研究所有限公司 | GNSS ground station signal intelligent receiving method based on interference monitoring assistance |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116794691A (en) * | 2023-08-25 | 2023-09-22 | 长沙金维信息技术有限公司 | Navigation signal capturing system and method |
| CN116794691B (en) * | 2023-08-25 | 2023-11-07 | 长沙金维信息技术有限公司 | Navigation signal capturing system and method |
| CN117492036A (en) * | 2023-11-03 | 2024-02-02 | 河南省科学院应用物理研究所有限公司 | GNSS ground station signal intelligent receiving method based on interference monitoring assistance |
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