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

Abstract

The application provides a real-time GNSS interference detection method and device based on carrier-to-noise ratio, determines carrier-to-noise ratio thresholds of different satellite systems and different frequency signals, analyzes first preset format GGA data and second preset format GSV data in received real-time GNSS information, acquires azimuth, elevation and carrier-to-noise ratio at the current moment according to the GGA data and the GSV data, compares different frequency carrier-to-noise ratios of different satellite systems with corresponding carrier-to-noise ratio thresholds to determine interference, divides a complete azimuth interval into M intervals according to a preset rule, determines total satellite numbers in each interval and satellite numbers interfered in each interval at each moment, calculates an interference ratio, and judges whether the interval is abnormal when the interference ratio exceeds an interference threshold. The application can acquire satellite elevation, azimuth and carrier-to-noise ratio and other information through real-time GGA format and GSV format data, thereby realizing real-time GNSS signal interference detection, making interference detection more convenient and lower in cost.

Description

Technical Field

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

[0002] Because the modulation parameters and coding rules of civilian satellite signals are public information, and because these signals travel long distances, they are easily deceived or interfered with, thus affecting 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 apparatus based on carrier-to-noise ratio that overcomes or at least partially solves the above-mentioned problems.

[0004] To achieve the above objectives, 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] The carrier-to-noise ratio thresholds for different satellite systems and signals at different frequencies are determined based on the minimum power level of the navigation signals transmitted by the satellite reaching the output of the receiver antenna.

[0007] Receive real-time GNSS information according to a preset protocol;

[0008] The first preset format GGA data and the second preset format GSV data in the received GNSS real-time information are parsed.

[0009] The azimuth, elevation, and carrier-to-noise ratio at the current moment are obtained based on the GGA data and the GSV data.

[0010] The carrier-to-noise ratios of different frequencies of different satellite systems are compared with the corresponding carrier-to-noise ratio thresholds. If the preset conditions are met, the frequency signals that meet the preset conditions are determined to be interfered with.

[0011] The complete azimuth interval is divided into M intervals according to preset rules;

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

[0013] Determine whether the interference ratio exceeds the interference threshold. If it does, then determine that the interval is abnormal.

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

[0015] The minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output terminal is obtained according to the space signal interface control file of different satellite systems;

[0016] At dB level, taking into account the properties of logarithmic calculations, the carrier-to-noise ratio threshold is calculated using the following formula:

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

[0018] The typical value of N0 is -204 dBW / Hz.

[0019] Optionally, the first preset format GGA data 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 UTC time, <2> Latitude <3> It is a latitudinal hemisphere. <4> Longitude <5> For the longitude hemisphere, <6> The positioning modes are 0 for unavailable, 1 for standard positioning mode, 2 for differential mode, 3 for precise positioning mode, 4 for RTK fixed solution, 5 for RTK floating-point solution, and 6 for inertial navigation system dead reckoning. <7> For the number of satellites, <8> For horizontal precision factor, <9> It is a positive high. <10> for <9> The unit of height, <11> The difference in geoid level, <12> for <11> The unit of height, <13> For the differential data period, <14> For reference base station ID, <15> For checksum.

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

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

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

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

[0026] Using n degrees as a granularity, the complete azimuth angle range [0, 360] is divided into... Each interval:

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

[0028] The determination module is used to determine the carrier-to-noise ratio threshold for different satellite systems and signals at different frequencies based on the minimum power level of the navigation signals transmitted by the satellite reaching the output of the receiver antenna;

[0029] The receiving module is used to receive real-time GNSS information according to a preset protocol.

[0030] The parsing module is used to parse the GGA data in the first preset format and the GSV data in the second preset format in the received GNSS real-time information;

[0031] The acquisition module is used to acquire the azimuth angle, elevation angle and carrier-to-noise ratio at the current moment based on the GGA data and the GSV data;

[0032] The comparison module is used to compare the carrier-to-noise ratio (CNR) of different frequency points of different satellite systems with the corresponding CNR threshold. If the preset conditions are met, it is determined that the frequency point signal that meets the preset conditions is interfered with.

[0033] The division module is used to divide the complete azimuth angle interval into M intervals according to preset rules;

[0034] The calculation module is used to determine the total number of satellites at each time point and in each interval, as well as the number of satellites receiving interference in each interval, and to calculate the interference ratio.

[0035] The judgment module is used to determine whether the interference ratio exceeds the interference threshold. If it exceeds the interference threshold, the interval is determined to be abnormal.

[0036] Optionally, the determining module determines the carrier-to-noise ratio threshold for different satellite systems and signals at different frequencies based on the minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output terminal:

[0037] The minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output terminal is obtained according to the space signal interface control file of different satellite systems;

[0038] At dB level, taking into account the properties of logarithmic calculations, the carrier-to-noise ratio threshold is calculated using the following formula:

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

[0040] The typical value of N0 is -204 dBW / Hz.

[0041] Optionally, the first preset format GGA data 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> Latitude <3> It is a latitudinal hemisphere. <4> Longitude <5> For the longitude hemisphere, <6> The positioning modes are 0 for unavailable, 1 for standard positioning mode, 2 for differential mode, 3 for precise positioning mode, 4 for RTK fixed solution, 5 for RTK floating-point solution, and 6 for inertial navigation system dead reckoning. <7> For the number of satellites, <8> For horizontal precision factor, <9> It is a positive high. <10> for <9> The unit of height, <11> The difference in geoid level, <12> for <11> The unit of height, <13> For the differential data period, <14> For reference base station ID, <15> For checksum.

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

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

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

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

[0048] Using n degrees as a granularity, the complete azimuth angle range [0, 360] is divided into... Each interval:

[0049] Therefore, the real-time GNSS interference detection method and device based on carrier-to-noise ratio provided by this invention can obtain information such as satellite elevation angle, azimuth angle and carrier-to-noise ratio through real-time GGA format and GSV format data, thereby realizing real-time GNSS signal interference detection, making interference detection simpler and cheaper. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0052] Figure 2 This is a schematic diagram of the structure of a real-time GNSS interference detection device based on carrier-to-noise ratio provided in an embodiment of the present invention. Detailed Implementation

[0053] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0054] Figure 1 A flowchart of the real-time GNSS interference detection method based on carrier-to-noise ratio provided in an embodiment of the present invention is shown. See also... Figure 1 The real-time GNSS interference detection method based on carrier-to-noise ratio provided in this embodiment of the invention includes:

[0055] S1. Determine the carrier-to-noise ratio threshold for different satellite systems and signals at different frequencies based on the minimum power level of the navigation signal transmitted by the satellite reaching the output of the receiver antenna.

[0056] As an optional implementation of this invention, determining the carrier-to-noise ratio threshold for different satellite systems and signals at different frequencies based on the minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output includes:

[0057] The minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output is obtained from the space signal interface control file of different satellite systems.

[0058] At dB level, taking into account the properties of logarithmic calculations, the carrier-to-noise ratio threshold is calculated using the following formula:

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

[0060] The typical value of N0 is -204 dBW / Hz.

[0061] Specifically, this invention determines the carrier-to-noise ratio threshold for signals from different satellite systems and at different frequencies based on the minimum power level of the navigation signal transmitted by the satellite reaching the output of the receiver antenna.

[0062] in:

[0063] The carrier-to-noise ratio (CNR) is measured in dB·Hz and is defined 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 N0 represents the power of the received satellite signal. The specific calculation method for N0 is as follows;

[0066] N0=k·T

[0067] Where, k = 1.38 × 10 -23 J / K is the Bolmann constant; T is the noise temperature, in Kelvin (K). A typical receiver's N0 value at 290K is -204 dBW / Hz.

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

[0069] C / N0 = SNR × B n

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

[0071] The minimum power level (in dBW) of the navigation signal transmitted by the satellite reaching the receiver antenna output can be obtained from the space signal interface control file of different satellite systems.

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

[0073]

[0074] dBW is a relative quantity, which is obtained by assigning the reference power P2 in the dB formula a value of 1W. The expression for dBW is as follows:

[0075]

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

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

[0078] The carrier-to-noise ratio (CNR) values ​​corresponding to the minimum power of different satellite systems are calculated using the above formula. These values ​​are then used as the CNR thresholds for different frequency points of different satellite systems. Specific values ​​are shown in Table 1 below.

[0079] Table 1

[0080]

[0081] S2 receives real-time GNSS information according to a preset protocol.

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

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

[0084] As an optional implementation of this invention, the first preset format GGA data 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 UTC time, <2> Latitude <3> It is a latitudinal hemisphere. <4> Longitude <5> For the longitude hemisphere, <6> The positioning modes are 0 for unavailable, 1 for standard positioning mode, 2 for differential mode, 3 for precise positioning mode, 4 for RTK fixed solution, 5 for RTK floating-point solution, and 6 for inertial navigation system dead reckoning. <7> For the number of satellites, <8> For horizontal precision factor, <9> It is a positive high. <10> for <9> The unit of height, <11> The difference in geoid level, <12> for <11> The unit of height, <13> For the differential data period, <14> For reference base station ID, <15> For checksum.

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

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

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

[0090] Specifically, this 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 correspondences are shown in Table 2 above; <1> To locate UTC time, the format is hhmmss.ss (hours, minutes, seconds.seconds); <2> For latitude, the format is ddmm.mmmm (degrees / minutes.minutes); <3> It represents the latitudinal hemisphere, where N represents North Latitude and S represents South Latitude. <4> This is for longitude, in the format dddmm.mmmm (degrees in minutes.minutes); <5> The longitude hemisphere is represented by E, which stands for East Longitude and W, which stands for West Longitude. <6> The positioning modes are: 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 solution, and 6 represents inertial navigation system dead reckoning. <7> Number of satellites; <8> HDOP (Horizontal Precision Factor); <9> It is a positive high; <10> for <9> The unit of height, M, indicates the unit as meters; <11> The difference in geoid level; <12> for <11> The unit of height, M, indicates the unit as meters; <13> For differential data period; <14> Reference base station ID; <15> For checksum.

[0095] This 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 correspondence is shown in Table 2; <1> Total number of GSV statements; <2> Number the statements; <3> Total number of satellites; <4> For satellite PRN number; <5> The pitch angle is expressed in degrees, with a maximum of 90°. <6> The azimuth angle is in degrees and ranges from 000° to 359°. <7> Signal-to-noise ratio (SNR); <8> For checksums. Each satellite's... <4> , <5> , <6> , <7> The information will be displayed sequentially, with each GSV statement showing information on a maximum of four satellites.

[0098] S4. Obtain the azimuth, elevation, and carrier-to-noise ratio at the current moment based on GGA and GSV data.

[0099] S5 compares the carrier-to-noise ratio (CNR) of different frequencies of different satellite systems with the corresponding CNR threshold. If the preset conditions are met, it is determined that the frequency signal that meets the preset conditions is being interfered with.

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

[0101] This process is repeated to assess interference for each satellite.

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

[0103] S6 divides the complete azimuth interval into M intervals according to preset rules.

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

[0105] Using n degrees as a granularity, the complete azimuth angle range [0, 360] is divided into... Each interval:

[0106] Specifically, the present invention can divide the complete azimuth angle interval [0, 360] into units of n degrees. Each interval: 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 angle range in other ways, such as setting each range to be of unequal size according to the number of satellites, which is not specifically limited in the present invention.

[0108] S7, determine the total number of satellites at each time point and in each interval, as well as the number of satellites receiving interference in each interval, and calculate the interference ratio.

[0109] Specifically, this invention counts the total number of satellites and the number of interfered satellites within each interval at each time point, and calculates the interference ratio based on the total number of satellites and the number of interfered satellites in each interval:

[0110]

[0111] S8, determine whether the interference ratio exceeds the interference threshold. If it exceeds the interference threshold, then determine that the interval is abnormal.

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

[0113] Therefore, the real-time GNSS interference detection method based on carrier-to-noise ratio provided by this invention can obtain information such as satellite elevation angle, azimuth angle and carrier-to-noise ratio through real-time GGA format and GSV format data, thereby realizing real-time GNSS signal interference detection, making interference detection simpler and cheaper.

[0114] Figure 2 This diagram illustrates the structure of a real-time GNSS interference detection device based on carrier-to-noise ratio (CNR) according to an embodiment of the present invention. This CNR-based real-time GNSS interference detection device applies the aforementioned method. The following is only a brief description of the structure of the CNR-based real-time GNSS interference detection device; for other matters not covered herein, please refer to the relevant descriptions in the aforementioned real-time GNSS interference detection method based on CNR. Figure 2 The real-time GNSS interference detection device based on carrier-to-noise ratio provided in this embodiment of the invention includes:

[0115] The determination module is used to determine the carrier-to-noise ratio threshold for different satellite systems and signals at different frequencies based on the minimum power level of the navigation signals transmitted by the satellite reaching the output of the receiver antenna;

[0116] The receiving module is used to receive real-time GNSS information according to a preset protocol.

[0117] The parsing module is used to parse the first preset format GGA data and the second preset format GSV data in the received GNSS real-time information.

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

[0119] The comparison module is used to compare the carrier-to-noise ratio (CNR) of different frequency points of different satellite systems with the corresponding CNR threshold. If the preset conditions are met, it is determined that the frequency point signal that meets the preset conditions is interfered with.

[0120] The division module is used to divide the complete azimuth angle interval into M intervals according to preset rules;

[0121] The calculation module is used to determine the total number of satellites at each time point and in each interval, as well as the number of satellites receiving interference in each interval, and to calculate the interference ratio.

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

[0123] As an optional implementation of this invention, the determining module determines the carrier-to-noise ratio threshold for different satellite systems and signals at different frequencies based on the minimum power level of the navigation signal transmitted by the satellite reaching the output of the receiver antenna in the following manner:

[0124] The minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output is obtained from the space signal interface control file of different satellite systems.

[0125] At dB level, taking into account the properties of logarithmic calculations, the carrier-to-noise ratio threshold is calculated using the following formula:

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

[0127] The typical value of N0 is -204 dBW / Hz.

[0128] As an optional implementation of this invention, the first preset format GGA data 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> Latitude <3> It is a latitudinal hemisphere. <4> Longitude <5> For the longitude hemisphere, <6> The positioning modes are 0 for unavailable, 1 for standard positioning mode, 2 for differential mode, 3 for precise positioning mode, 4 for RTK fixed solution, 5 for RTK floating-point solution, and 6 for inertial navigation system dead reckoning. <7> For the number of satellites, <8> For horizontal precision factor, <9> It is a positive high. <10> for <9> The unit of height, <11> The difference in geoid level, <12> for <11> The unit of height, <13> For the differential data period, <14> For reference base station ID, <15> For checksum.

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

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

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

[0134] As an optional implementation of this invention, the division module divides the complete azimuth angle interval into M intervals according to preset rules in the following manner:

[0135] Using n degrees as a granularity, the complete azimuth angle range [0, 360] is divided into... Each interval:

[0136] Therefore, the real-time GNSS interference detection device based on carrier-to-noise ratio provided by this invention can obtain information such as satellite elevation angle, azimuth angle and carrier-to-noise ratio through real-time GGA format and GSV format data, thereby realizing real-time GNSS signal interference detection, making interference detection simpler and cheaper.

[0137] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A real-time GNSS interference detection method based on carrier-to-noise ratio, characterized in that, include: The carrier-to-noise ratio thresholds for different satellite systems and signals at different frequencies are determined based on the minimum power level of the navigation signals transmitted by the satellite reaching the output of the receiver antenna. Receive real-time GNSS information according to a preset protocol; The first preset format GGA data and the second preset format GSV data in the received GNSS real-time information are parsed. The azimuth, elevation, and carrier-to-noise ratio at the current moment are obtained based on the GGA data and the GSV data. The carrier-to-noise ratios of different frequencies of different satellite systems are compared with the corresponding carrier-to-noise ratio thresholds. If the preset conditions are met, the frequency signals that meet the preset conditions are determined to be interfered with. The complete azimuth interval is divided into M intervals according to preset rules; Determine the total number of satellites at each time point and within each interval, as well as the number of satellites receiving interference within each interval, and calculate the interference ratio; Determine whether the interference ratio exceeds the interference threshold; if it does, determine that the interval is abnormal. in: The determination of the carrier-to-noise ratio thresholds for different satellite systems and different frequency signals based on the minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output includes: The minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output terminal is obtained according to the space signal interface control file of different satellite systems; At dB level, taking into account the properties of logarithmic calculations, the carrier-to-noise ratio threshold is calculated using the following formula: Carrier-to-noise ratio = minimum power level - typical value of N0 The typical value of N0 is -204 dBW / Hz.

2. The method according to claim 1, characterized in that, The first preset format GGA data 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> Latitude <3> It is a latitudinal hemisphere. <4> Longitude <5> For the longitude hemisphere, <6> The positioning modes are 0 for unavailable, 1 for standard positioning mode, 2 for differential mode, 3 for precise positioning mode, 4 for RTK fixed solution, 5 for RTK floating-point solution, and 6 for inertial navigation system dead reckoning. <7> For the number of satellites, <8> For horizontal precision factor, <9> It is a positive high. <10> for <9> The unit of height, <11> The difference in geoid level, <12> for <11> The unit of height, <13> For the differential data period, <14> For reference base station ID, <15> For checksum.

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

4. The method according to any one of claims 1 to 3, characterized in that, The step of dividing the complete azimuth angle interval into M intervals according to preset rules includes: Using n degrees as a granularity, the complete azimuth angle range [0, 360] is divided into... Each interval:

5. A real-time GNSS interference detection device based on carrier-to-noise ratio, characterized in that, include: The determination module is used to determine the carrier-to-noise ratio threshold for different satellite systems and signals at different frequencies based on the minimum power level of the navigation signals transmitted by the satellite reaching the output of the receiver antenna; The receiving module is used to receive real-time GNSS information according to a preset protocol. The parsing module is used to parse the GGA data in the first preset format and the GSV data in the second preset format in the received GNSS real-time information; The acquisition module is used to acquire the azimuth angle, elevation angle and carrier-to-noise ratio at the current moment based on the GGA data and the GSV data; The comparison module is used to compare the carrier-to-noise ratio (CNR) of different frequency points of different satellite systems with the corresponding CNR threshold. If the preset conditions are met, it is determined that the frequency point signal that meets the preset conditions is interfered with. The division module is used to divide the complete azimuth angle interval into M intervals according to preset rules; The calculation module is used to determine the total number of satellites at each time point and in each interval, as well as the number of satellites receiving interference in each interval, and to calculate the interference ratio. The judgment module is used to determine whether the interference ratio exceeds the interference threshold. If it exceeds the interference threshold, the interval is determined to be abnormal. in: The determining module determines the carrier-to-noise ratio threshold for different satellite systems and signals at different frequencies based on the minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output terminal in the following manner: The minimum power level of the navigation signal transmitted by the satellite reaching the receiver antenna output terminal is obtained according to the space signal interface control file of different satellite systems; At dB level, taking into account the properties of logarithmic calculations, the carrier-to-noise ratio threshold is calculated using the following formula: Carrier-to-noise ratio = minimum power level - typical value of N0 The typical value of N0 is -204 dBW / Hz.

6. The apparatus according to claim 5, characterized in that, The first preset format GGA data 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> Latitude <3> It is a latitudinal hemisphere. <4> Longitude <5> For the longitude hemisphere, <6> The positioning modes are 0 for unavailable, 1 for standard positioning mode, 2 for differential mode, 3 for precise positioning mode, 4 for RTK fixed solution, 5 for RTK floating-point solution, and 6 for inertial navigation system dead reckoning. <7> For the number of satellites, <8> For horizontal precision factor, <9> It is a positive high. <10> for <9> The unit of height, <11> The difference in geoid level, <12> for <11> The unit of height, <13> For the differential data period, <14> For reference base station ID, <15> For checksum.

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

8. The apparatus according to any one of claims 5 to 7, characterized in that, The division module divides the complete azimuth angle interval into M intervals according to preset rules in the following manner: Using n degrees as a granularity, the complete azimuth angle range [0, 360] is divided into... Each interval:

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