Real-time GNSS interference detection method and device based on carrier-to-noise ratio

Abstract

The invention provides a real-time GNSS (Global Navigation Satellite System) interference detection method and device based on a carrier-to-noise ratio. The method comprises the following steps: determining carrier-to-noise ratio thresholds of different satellite systems and different frequency point signals; analyzing GGA data in a first preset format and GSV data in a second preset format in the received GNSS real-time information; acquiring an azimuth angle, a pitch angle and a carrier-to-noise ratio at the current moment according to the GGA data and the GSV data; comparing the carrier-to-noise ratios of different frequency points of different satellite systems with corresponding carrier-to-noise ratio thresholds to determine interference; dividing the complete interval of the azimuth angle into M intervals according to a preset rule; determining the total number of satellites in each interval at each moment and the number of interfered satellites in each interval, and calculating an interference proportion; and determining that the interval is abnormal if the interference proportion exceeds the interference threshold. According to the method, information such as the pitch angle, the azimuth angle and the carrier-to-noise ratio of the satellite can be obtained through the real-time GGA format data and the GSV format data, so that real-time GNSS signal interference detection is realized, interference detection is simpler and more convenient, and the cost is lower.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation interference detection technology, and in particular to a real-time GNSS interference detection method and device based on carrier-to-noise ratio. Background Art

[0002] Since the modulation parameters and coding rules of civil satellite signals are public information and the signal propagation distance is long, these signals are easily deceived or interfered, thus affecting the positioning results. Existing GNSS (Global Navigation Satellite System) interference detection methods are usually complex and costly. In practical applications, a simpler and lower-cost interference detection method is needed. Summary of the invention

[0003] The present invention aims to provide a real-time GNSS interference detection method and device based on carrier-to-noise ratio that overcomes the above problems or at least partially solves the above problems.

[0004] To achieve the above object, the technical solution of the present invention is specifically implemented as follows:

[0005] One aspect of the present invention provides a real-time GNSS interference detection method based on carrier-to-noise ratio, comprising:

[0006] Determine the carrier-to-noise ratio thresholds of different satellite systems and different frequency signals based on the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna;

[0007] Receive GNSS real-time information with preset protocol;

[0008] Parsing the GGA data in a first preset format and the GSV data in a second preset format in the received GNSS real-time information;

[0009] Acquire the azimuth, elevation and carrier-to-noise ratio at the current moment according to the GGA data and the GSV data;

[0010] Compare the carrier-to-noise ratios of different frequencies of different satellite systems with corresponding carrier-to-noise ratio thresholds, and if a preset condition is met, determine that the frequency signal that meets the preset condition is interfered;

[0011] Divide the complete azimuth interval into M intervals according to a preset rule;

[0012] Determine the total number of satellites in each interval at each time and the number of satellites receiving interference in each interval, and calculate the interference ratio;

[0013] It is determined whether the interference ratio exceeds an interference threshold, and if so, the interval is determined to be abnormal.

[0014] Optionally, determining the carrier-to-noise ratio thresholds of different satellite systems and different frequency point signals according to the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna includes:

[0015] Acquire the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna according to the space signal interface control files of different satellite systems;

[0016] In dB units, combined with the logarithmic calculation properties, the carrier-to-noise ratio threshold is calculated according to the following formula:

[0017] Carrier-to-noise ratio = minimum power level - typical value of N0

[0018] Among them, the typical value of N0 is -204dBW / Hz.

[0019] Optionally, the GGA data in the first preset format includes:

[0020] $ <0> GGA, <1> , <2> , <3> , <4> , <5> , <6> , <7> , <8> , <9> , <10> , <11> , <12> , <13> , <14> * <15>

[0021] in, <0> For satellite systems, <1> To locate the UTC time, <2> is the latitude, <3> is the latitude hemisphere, <4> is the longitude, <5> is the longitude hemisphere, <6> is the positioning mode, 0 represents unavailable, 1 represents standard positioning mode, 2 represents differential mode, 3 represents precise positioning mode, 4 represents RTK fixed solution, 5 represents RTK floating point solution, and 6 represents inertial navigation system dead reckoning. <7> is the number of satellites, <8> is the horizontal precision factor, <9> For positive height, <10> for <9> The height unit, <11> is the geoid difference, <12> for <11> The height unit, <13> is the differential data period, <14> is the reference base station ID, <15> is the checksum.

[0022] Optionally, the GSV data in the second preset format includes:

[0023] $ <0> GSV, <1> , <2> , <3> , <4> , <5> , <6> , <7> ,… <4> , <5> , <6> , <7> * <8>

[0024] in, <0> For satellite systems, <1> is the total number of GSV statements, <2> Number the statement. <3> is the total number of satellites, <4> is the satellite PRN number, <5> is the pitch angle, <6> is the azimuth, <7> is the signal-to-noise ratio, <8> is the checksum.

[0025] Optionally, dividing the complete azimuth interval into M intervals according to a preset rule includes:

[0026] Taking n degrees as a granularity, the complete azimuth interval [0,360] is divided into Intervals:

[0027] Another aspect of the present invention provides a real-time GNSS interference detection device based on carrier-to-noise ratio, comprising:

[0028] A determination module, used to determine the carrier-to-noise ratio thresholds of different satellite systems and different frequency signals according to the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna;

[0029] A receiving module, used for receiving GNSS real-time information of a preset protocol;

[0030] A parsing module, used for parsing the GGA data in a first preset format and the GSV data in a second preset format in the received GNSS real-time information;

[0031] An acquisition module, used for acquiring the azimuth, pitch angle and carrier-to-noise ratio at the current moment according to the GGA data and the GSV data;

[0032] A comparison module is used to compare the carrier-to-noise ratios of different frequencies of different satellite systems with corresponding carrier-to-noise ratio thresholds. If a preset condition is met, it is determined that the frequency signal that meets the preset condition is interfered;

[0033] A division module, used for dividing the complete azimuth interval into M intervals according to a preset rule;

[0034] A calculation module, used to determine the total number of satellites in each interval at each time and the number of satellites receiving interference in each interval, and calculate the interference ratio;

[0035] The judgment module is used to judge whether the interference ratio exceeds the interference threshold, and if it exceeds the interference threshold, determine that the interval is abnormal.

[0036] Optionally, the determination module determines the carrier-to-noise ratio thresholds of different satellite systems and different frequency point signals according to the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna in the following manner:

[0037] Acquire the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna according to the space signal interface control files of different satellite systems;

[0038] In dB units, combined with the logarithmic calculation properties, the carrier-to-noise ratio threshold is calculated according to the following formula:

[0039] Carrier-to-noise ratio = minimum power level - typical value of N0

[0040] Among them, the typical value of N0 is -204dBW / Hz.

[0041] Optionally, the GGA data in the first preset format includes:

[0042] $ <0> GGA, <1> , <2> , <3> , <4> , <5> , <6> , <7> , <8> , <9> , <10> , <11> , <12> , <13> , <14> * <15>

[0043] in, <0> For satellite systems, <1> To locate UTC time, <2> is the latitude, <3> is the latitude hemisphere, <4> is the longitude, <5> is the longitude hemisphere, <6> is the positioning mode, 0 represents unavailable, 1 represents standard positioning mode, 2 represents differential mode, 3 represents precise positioning mode, 4 represents RTK fixed solution, 5 represents RTK floating point solution, and 6 represents inertial navigation system dead reckoning. <7> is the number of satellites, <8> is the horizontal precision factor, <9> For positive height, <10> for <9> The height unit, <11> is the geoid difference, <12> for <11> The height unit, <13> is the differential data period, <14> is the reference base station ID, <15> is the checksum.

[0044] Optionally, the GSV data in the second preset format includes:

[0045] $ <0> GSV, <1> , <2> , <3> , <4> , <5> , <6> , <7> ,… <4> , <5> , <6> , <7> * <8>

[0046] in, <0> For satellite systems, <1> is the total number of GSV statements, <2> Number the statement. <3> is the total number of satellites, <4> is the satellite PRN number, <5> is the pitch angle, <6> is the azimuth, <7> is the signal-to-noise ratio, <8> is the checksum.

[0047] Optionally, the division module divides the azimuth complete interval into M intervals according to a preset rule in the following manner:

[0048] Taking n degrees as a granularity, the azimuth angle interval [0,360] is divided into Intervals:

[0049] It can be seen that, through the real-time GNSS interference detection method and device based on carrier-to-noise ratio provided by the present invention, information such as satellite pitch angle, azimuth angle and carrier-to-noise ratio can be obtained through real-time GGA format and GSV format data, thereby realizing real-time GNSS signal interference detection, making interference detection simpler and less costly. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0051] Figure 1 A flowchart of a real-time GNSS interference detection method based on carrier-to-noise ratio provided in an embodiment of the present invention;

[0052] Figure 2 A schematic structural diagram of a real-time GNSS interference detection device based on carrier-to-noise ratio provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0054] Figure 1 A flowchart of a real-time GNSS interference detection method based on carrier-to-noise ratio provided by an embodiment of the present invention is shown. Figure 1 The embodiment of the present invention provides a real-time GNSS interference detection method based on carrier-to-noise ratio, comprising:

[0055] S1, determine the carrier-to-noise ratio thresholds of different satellite systems and different frequency signals based on the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna.

[0056] As an optional implementation of the embodiment of the present invention, determining the carrier-to-noise ratio thresholds of different satellite systems and different frequency point signals according to the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna includes:

[0057] According to the space signal interface control files of different satellite systems, the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna is obtained;

[0058] In dB units, combined with the logarithmic calculation properties, the carrier-to-noise ratio threshold is calculated according to the following formula:

[0059] Carrier-to-noise ratio = minimum power level - typical value of N0

[0060] Among them, the typical value of N0 is -204dBW / Hz.

[0061] Specifically, the present invention determines the carrier-to-noise ratio thresholds of different satellite systems and different frequency point signals based on the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna.

[0062] in:

[0063] The unit of carrier-to-noise ratio is dB·Hz. The definition of carrier-to-noise ratio is as follows:

[0064] C / N0=P R / N0

[0065] Where C is the signal power received by the satellite; N0 is the power spectral density of the noise; P R is the power of the received satellite signal. The specific calculation method of N0 is as follows;

[0066] N0=k·T

[0067] Where k = 1.38 × 10 -23 J / K is the Boltz constant; T is the noise temperature, in Kelvin (K). The typical value of N0 for a general receiver at a temperature of 290K is -204dBW / Hz.

[0068] The relationship between carrier-to-noise ratio and signal-to-noise ratio is:

[0069] C / N0=SNR×B n

[0070] Among them, B n is the noise bandwidth.

[0071] According to the space signal interface control files of different satellite systems, the minimum power level (in dBW) of the navigation signal transmitted by the satellite to reach the output end of the receiver antenna can be obtained.

[0072] It is known that decibel (dB) is an absolute quantity, and its calculation formula is as follows, which represents the magnitude relationship of power P1 relative to reference power P2.

[0073]

[0074] dBW is a relative quantity, which is the reference power P2 in the dB formula assigned to 1w. The expression of dBW is as follows:

[0075]

[0076] In dB units, based on the logarithmic calculation properties, the division of power ratios can be converted into subtraction of dB values ​​for calculation.

[0077] Carrier-to-noise ratio = minimum power level - typical value of N0

[0078] According to the above formula, the carrier-to-noise ratio values ​​corresponding to the minimum power of different satellite systems are calculated, and this value is used as the basis for the carrier-to-noise ratio thresholds of different satellite systems at different frequencies. The specific values ​​are shown in Table 1:

[0079] Table 1

[0080]

[0081] S2, receiving GNSS real-time information of a preset protocol.

[0082] Specifically, the present invention can receive GNSS real-time information using the NMEA0183 protocol.

[0083] S3, parsing the GGA data in the first preset format and the GSV data in the second preset format in the received GNSS real-time information.

[0084] As an optional implementation of the embodiment of the present invention, the GGA data in the first preset format includes:

[0085] $ <0> GGA, <1> , <2> , <3> , <4> , <5> , <6> , <7> , <8> , <9> , <10> , <11> , <12> , <13> , <14> * <15>

[0086] in, <0> For satellite systems, <1> To locate the UTC time, <2> is the latitude, <3> is the latitude hemisphere, <4> is the longitude, <5> is the longitude hemisphere, <6> is the positioning mode, 0 represents unavailable, 1 represents standard positioning mode, 2 represents differential mode, 3 represents precise positioning mode, 4 represents RTK fixed solution, 5 represents RTK floating point solution, and 6 represents inertial navigation system dead reckoning. <7> is the number of satellites, <8> is the horizontal precision factor, <9> For positive height, <10> for <9> The height unit, <11> is the geoid difference, <12> for <11> The height unit, <13> is the differential data period, <14> is the reference base station ID, <15> is the checksum.

[0087] As an optional implementation of the embodiment of the present invention, the GSV data in the second preset format includes:

[0088] $ <0> GSV, <1> , <2> , <3> , <4> , <5> , <6> , <7> ,… <4> , <5> , <6> , <7> * <8>

[0089] in, <0> For satellite systems, <1> is the total number of GSV statements, <2> Number the statement. <3> is the total number of satellites, <4> is the satellite PRN number, <5> is the pitch angle, <6> is the azimuth, <7> is the signal-to-noise ratio, <8> is the checksum.

[0090] Specifically, the present invention parses the GGA data in the information received in step S2. The string format of the GGA data is:

[0091] $ <0> GGA, <1> , <2> , <3> , <4> , <5> , <6> , <7> , <8> , <9> , <10> , <11> , <12> , <13> , <14> * <15>

[0092] Table 2

[0093]

[0094] in: <0> For satellite systems, the specific corresponding relationship is shown in Table 2 above; <1> To locate UTC time, the format is hhmmss.ss (hour, minute, second.second); <2> is latitude, the format is ddmm.mmmm (degrees, minutes, minutes); <3> It is the latitude hemisphere, N represents north latitude and S represents south latitude. <4> is the longitude, the format is dddmm.mmmm (degrees, minutes, minutes); <5> It is the longitude hemisphere, E represents east longitude and W represents west longitude. <6> is the positioning mode, 0 represents unavailable, 1 represents standard positioning mode, 2 represents differential mode, 3 represents precise positioning mode, 4 represents RTK fixed solution, 5 represents RTK floating point solution, and 6 represents inertial navigation system dead reckoning; <7> is the number of satellites; <8> is the HDOP (horizontal dilution of precision); <9> It is positive height; <10> for <9> The unit of height, M means the unit is meter; <11> is the geoid difference; <12> for <11> The unit of height, M means the unit is meter; <13> is the differential data period; <14> is the reference base station ID; <15> is the checksum.

[0095] The present invention parses the GSV data in the information received in step S2. The string format of the GSV data is:

[0096] $ <0> GSV, <1> , <2> , <3> , <4> , <5> , <6> , <7> ,… <4> , <5> , <6> , <7> * <8>

[0097] in: <0> For satellite systems, the specific corresponding relationship is shown in Table 2; <1> is the total number of GSV statements; <2> Number the statements; <3> is the total number of satellites; <4> is the satellite PRN number; <5> is the pitch angle, in degrees, with a maximum of 90°; <6> is the azimuth in degrees, ranging from 000° to 359°; <7> is the signal-to-noise ratio (SNR); <8> is the checksum. <4> , <5> , <6> , <7> It will be displayed sequentially, with each GSV sentence showing information of up to 4 satellites.

[0098] S4, obtaining the azimuth, elevation angle and carrier-to-noise ratio at the current moment according to the GGA data and GSV data;

[0099] S5, comparing the carrier-to-noise ratios of different frequencies of different satellite systems with corresponding carrier-to-noise ratio thresholds, and if a preset condition is met, determining that the frequency signal meeting the preset condition is interfered.

[0100] Specifically, the present invention obtains information such as satellite azimuth, elevation angle and carrier-to-noise ratio at the current time based on real-time GGA and GSV format data. The carrier-to-noise ratio values ​​of different frequencies of different satellite systems are compared with the corresponding carrier-to-noise ratio thresholds. If the carrier-to-noise ratio is lower than the corresponding threshold of 10 dB·Hz, the signal at the frequency point is considered to be interfered.

[0101] This process repeats itself to make interference judgments for each satellite.

[0102] As an optional implementation manner of an embodiment of the present invention, the real-time GNSS interference detection method based on carrier-to-noise ratio provided in an embodiment of the present invention further includes: recording the satellite number, frequency information, pitch angle, azimuth angle, and carrier-to-noise ratio value.

[0103] S6, dividing the complete azimuth interval into M intervals according to a preset rule.

[0104] As an optional implementation of the embodiment of the present invention, dividing the azimuth angle complete interval into M intervals according to a preset rule includes:

[0105] Taking n degrees as a granularity, the azimuth angle interval [0,360] is divided into Intervals:

[0106] Specifically, the present invention can divide the azimuth angle full interval [0,360] into n degrees as a granularity. Intervals: Each interval represents a certain range of azimuth angles, and the specific value of n can be determined according to specific requirements, such as 15°.

[0107] Of course, the present invention can also divide the complete azimuth interval into other ways, such as setting each interval to be of different sizes according to the number of satellites, which is not specifically limited in the present invention.

[0108] S7, determining the total number of satellites in each interval at each time and the number of satellites receiving interference in each interval, and calculating the interference ratio.

[0109] Specifically, the present invention counts the total number of satellites in each interval and the number of satellites interfered in the interval at each moment, and calculates the interference ratio according to the total number of satellites and the number of interfered satellites in each interval:

[0110]

[0111] S8, determining whether the interference ratio exceeds an interference threshold, and if so, determining that the interval is abnormal.

[0112] Specifically, a ratio threshold is set according to actual needs, and each interval is judged to be abnormal according to the set threshold. If the interference ratio of a certain interval exceeds the threshold, the position is marked as abnormal and recorded. Assuming that the threshold is set to 85%, if the interference ratio of a certain interval is greater than 85%, it is considered that the position is abnormal.

[0113] It can be seen that through the real-time GNSS interference detection method based on carrier-to-noise ratio provided by the present invention, information such as satellite pitch angle, azimuth angle and carrier-to-noise ratio can be obtained through real-time GGA format and GSV format data, thereby realizing real-time GNSS signal interference detection, making interference detection simpler and less costly.

[0114] Figure 2 The structure diagram of the real-time GNSS interference detection device based on carrier-to-noise ratio provided by an embodiment of the present invention is shown. The real-time GNSS interference detection device based on carrier-to-noise ratio applies the above method. The following is only a brief description of the structure of the real-time GNSS interference detection device based on carrier-to-noise ratio. For other matters not covered, please refer to the relevant description in the real-time GNSS interference detection method based on carrier-to-noise ratio. Figure 2 , a real-time GNSS interference detection device based on carrier-to-noise ratio provided by an embodiment of the present invention comprises:

[0115] A determination module, used to determine the carrier-to-noise ratio thresholds of different satellite systems and different frequency signals according to the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna;

[0116] A receiving module, used for receiving GNSS real-time information of a preset protocol;

[0117] A parsing module, used for parsing GGA data in a first preset format and GSV data in a second preset format in the received GNSS real-time information;

[0118] The acquisition module is used to obtain the azimuth, pitch angle and carrier-to-noise ratio at the current moment based on the GGA data and GSV data;

[0119] A comparison module is used to compare the carrier-to-noise ratios of different frequencies of different satellite systems with corresponding carrier-to-noise ratio thresholds. If a preset condition is met, it is determined that the frequency signal that meets the preset condition is interfered;

[0120] A division module, used for dividing the complete azimuth interval into M intervals according to a preset rule;

[0121] A calculation module, used to determine the total number of satellites in each interval at each time and the number of satellites receiving interference in each interval, and calculate the interference ratio;

[0122] The judgment module is used to judge whether the interference ratio exceeds the interference threshold. If it exceeds the interference threshold, it is determined that the interval is abnormal.

[0123] As an optional implementation of the embodiment of the present invention, the determination module determines the carrier-to-noise ratio thresholds of different satellite systems and different frequency point signals according to the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna in the following manner:

[0124] According to the space signal interface control files of different satellite systems, the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna is obtained;

[0125] In dB units, combined with the logarithmic calculation properties, the carrier-to-noise ratio threshold is calculated according to the following formula:

[0126] Carrier-to-noise ratio = minimum power level - typical value of N0

[0127] Among them, the typical value of N0 is -204dBW / Hz.

[0128] As an optional implementation of the embodiment of the present invention, the GGA data in the first preset format includes:

[0129] $ <0> GGA, <1> , <2> , <3> , <4> , <5> , <6> , <7> , <8> , <9> , <10> , <11> , <12> , <13> , <14> * <15>

[0130] in, <0> For satellite systems, <1> To locate UTC time, <2> is the latitude, <3> is the latitude hemisphere, <4> is the longitude, <5> is the longitude hemisphere, <6> is the positioning mode, 0 represents unavailable, 1 represents standard positioning mode, 2 represents differential mode, 3 represents precise positioning mode, 4 represents RTK fixed solution, 5 represents RTK floating point solution, and 6 represents inertial navigation system dead reckoning. <7> is the number of satellites, <8> is the horizontal precision factor, <9> For positive height, <10> for <9> The height unit, <11> is the geoid difference, <12> for <11> The height unit, <13> is the differential data period, <14> is the reference base station ID, <15> is the checksum.

[0131] As an optional implementation of the embodiment of the present invention, the GSV data in the second preset format includes:

[0132] $ <0> GSV, <1> , <2> , <3> , <4> , <5> , <6> , <7> ,… <4> , <5> , <6> , <7> * <8>

[0133] in, <0> For satellite systems, <1> is the total number of GSV statements, <2> Number the statement. <3> is the total number of satellites, <4> is the satellite PRN number, <5> is the pitch angle, <6> is the azimuth, <7> is the signal-to-noise ratio, <8> is the checksum.

[0134] As an optional implementation of the embodiment of the present invention, the division module divides the azimuth complete interval into M intervals according to a preset rule in the following manner:

[0135] Taking n degrees as a granularity, the azimuth angle interval [0,360] is divided into Intervals:

[0136] It can be seen that, through the real-time GNSS interference detection device based on carrier-to-noise ratio provided by the present invention, information such as satellite pitch angle, azimuth angle and carrier-to-noise ratio can be obtained through real-time GGA format and GSV format data, thereby realizing real-time GNSS signal interference detection, making interference detection simpler and less costly.

[0137] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A real-time GNSS interference detection method based on carrier-to-noise ratio, characterized in that: include: Determine the carrier-to-noise ratio thresholds of different satellite systems and different frequency signals based on the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna; Receive GNSS real-time information with preset protocol; Parsing the GGA data in a first preset format and the GSV data in a second preset format in the received GNSS real-time information; Acquire the azimuth, elevation and carrier-to-noise ratio at the current moment according to the GGA data and the GSV data; Compare the carrier-to-noise ratios of different frequencies of different satellite systems with corresponding carrier-to-noise ratio thresholds, and if the preset conditions are met, determine that the frequency signals meeting the preset conditions are interfered; Divide the complete azimuth interval into M intervals according to a preset rule; Determine the total number of satellites in each interval at each time and the number of satellites receiving interference in each interval, and calculate the interference ratio; It is determined whether the interference ratio exceeds an interference threshold, and if so, the interval is determined to be abnormal.

2. The method according to claim 1, characterized in that Determining the carrier-to-noise ratio thresholds of different satellite systems and different frequency signals according to the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna includes: Acquire the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna according to the space signal interface control files of different satellite systems; In dB units, combined with the logarithmic calculation properties, the carrier-to-noise ratio threshold is calculated according to the following formula: Carrier-to-noise ratio = minimum power level - typical value of N0 Among them, the typical value of N0 is -204dBW / Hz.

3. The method according to claim 2, characterized in that The GGA data in the first preset format includes: $ <0> GGA, <1> , <2> , <3> , <4> , <5> , <6> , <7> , <8> , <9> , <10> , <11> , <12> , <13> , <14> * <15> in, <0> For satellite systems, <1> To locate UTC time, <2> is the latitude, <3> is the latitude hemisphere, <4> is the longitude, <5> is the longitude hemisphere, <6> is the positioning mode, 0 represents unavailable, 1 represents standard positioning mode, 2 represents differential mode, 3 represents precise positioning mode, 4 represents RTK fixed solution, 5 represents RTK floating point solution, and 6 represents inertial navigation system dead reckoning. <7> is the number of satellites, <8> is the horizontal precision factor, <9> For positive height, <10> for <9> The height unit, <11> is the geoid difference, <12> for <11> The height unit, <13> is the differential data period, <14> is the reference base station ID, <15> is the checksum.

4. The method according to claim 2, characterized in that: The GSV data in the second preset format includes: $ <0> GSV, <1> , <2> , <3> , <4> , <5> , <6> , <7> ,… <4> , <5> , <6> , <7> * <8> in, <0> For satellite systems, <1> is the total number of GSV statements, <2> Number the statement. <3> is the total number of satellites, <4> is the satellite PRN number, <5> is the pitch angle, <6> is the azimuth, <7> is the signal-to-noise ratio, <8> is the checksum.

5. The method according to any one of claims 1 to 4, characterized in that: The dividing of the complete azimuth interval into M intervals according to a preset rule comprises: Taking n degrees as a granularity, the azimuth angle interval [0,360] is divided into Intervals:

6. A real-time GNSS interference detection device based on carrier-to-noise ratio, characterized in that: include: A determination module, used to determine the carrier-to-noise ratio thresholds of different satellite systems and different frequency signals according to the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna; A receiving module, used for receiving GNSS real-time information of a preset protocol; A parsing module, used for parsing the GGA data in a first preset format and the GSV data in a second preset format in the received GNSS real-time information; An acquisition module, used for acquiring the azimuth, pitch angle and carrier-to-noise ratio at the current moment according to the GGA data and the GSV data; A comparison module is used to compare the carrier-to-noise ratios of different frequencies of different satellite systems with corresponding carrier-to-noise ratio thresholds. If a preset condition is met, it is determined that the frequency signal that meets the preset condition is interfered; A division module, used for dividing the complete azimuth interval into M intervals according to a preset rule; A calculation module, used to determine the total number of satellites in each interval at each time and the number of satellites receiving interference in each interval, and calculate the interference ratio; The judgment module is used to judge whether the interference ratio exceeds the interference threshold, and if it exceeds the interference threshold, determine that the interval is abnormal.

7. The device according to claim 6, characterized in that The determination module determines the carrier-to-noise ratio thresholds of different satellite systems and different frequency point signals according to the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna in the following manner: Acquire the minimum power level of the navigation signal transmitted by the satellite reaching the output end of the receiver antenna according to the space signal interface control files of different satellite systems; In dB units, combined with the logarithmic calculation properties, the carrier-to-noise ratio threshold is calculated according to the following formula: Carrier-to-noise ratio = minimum power level - typical value of N0 Among them, the typical value of N0 is -204dBW / Hz.

8. The device according to claim 7, characterized in that The GGA data in the first preset format includes: $ <0> GGA, <1> , <2> , <3> , <4> , <5> , <6> , <7> , <8> , <9> , <10> , <11> , <12> , <13> , <14> * <15> in, <0> For satellite systems, <1> To locate UTC time, <2> is the latitude, <3> is the latitude hemisphere, <4> is the longitude, <5> is the longitude hemisphere, <6> is the positioning mode, 0 represents unavailable, 1 represents standard positioning mode, 2 represents differential mode, 3 represents precise positioning mode, 4 represents RTK fixed solution, 5 represents RTK floating point solution, and 6 represents inertial navigation system dead reckoning. <7> is the number of satellites, <8> is the horizontal precision factor, <9> For positive height, <10> for <9> The height unit, <11> is the geoid difference, <12> for <11> The height unit, <13> is the differential data period, <14> is the reference base station ID, <15> is the checksum.

9. The device according to claim 7, characterized in that The GSV data in the second preset format includes: $ <0> GSV, <1> , <2> , <3> , <4> , <5> , <6> , <7> ,… <4> , <5> , <6> , <7> * <8> in, <0> For satellite systems, <1> is the total number of GSV statements, <2> Number the statement. <3> is the total number of satellites, <4> is the satellite PRN number, <5> is the pitch angle, <6> is the azimuth, <7> is the signal-to-noise ratio, <8> is the checksum.

10. The device according to any one of claims 6 to 9, characterized in that The division module divides the azimuth complete interval into M intervals according to a preset rule in the following manner: Taking n degrees as a granularity, the azimuth angle interval [0,360] is divided into Intervals:

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