A GNSS spoofing interference tracking method and system based on double satellites

Abstract

The present application provides a dual-satellite GNSS deceptive interference tracking method and system, which includes: when the deceptive interference emitted by the same deceptive interference source is propagated to two satellites respectively, performing correlation operations on the deceptive interference received by the two satellites; performing short-time coherent integration operations; performing fast Fourier transforms; taking multiple consecutive fast Fourier transform results as a group, performing incoherent integration operations; finding the maximum value; using a set threshold to distinguish the maximum value; when the tracking channel is configurable, configuring the tracking channel based on the delay time corresponding to the maximum value and the spectral line sequence of the fast Fourier transform; repeating the above steps to obtain a sequence of delay time and fast Fourier transform number combinations, which is the interference tracking result. The advantages of the present application are: it is applicable to a dual-satellite monitoring and positioning system, and provides a solution to the current problem of dual-satellite GNSS deceptive interference tracking.

Description

Technical Field

[0001] The present application relates to the field of GNSS interference monitoring technology and applications, and specifically to a dual-star-based GNSS deceptive interference tracking method and system. Background Art

[0002] Since its introduction, the Global Navigation Satellite System (GNSS) has rapidly permeated every aspect of human life, profoundly changing how we work and live. GNSS-based applications and systems continue to emerge, serving economic development, scientific research, and national defense, playing a vital role.

[0003] The continued expansion and deepening of GNSS applications in the military has led to increasing military-level GNSS confrontations and exposed the inherent vulnerabilities of GNSS. The emergence of malicious GNSS jamming, exemplified by GNSS spoofing, has significantly jeopardized the security of GNSS-based applications and systems. Consequently, GNSS spoofing jamming detection technology and its applications have become a current research focus.

[0004] GNSS spoofing jammers use the same modulation scheme as genuine GNSS signals, potentially invading GNSS receivers and causing them to output erroneous position, velocity, and time (PVT) information. Therefore, GNSS spoofing jammers pose an extremely high threat. Furthermore, since the power of GNSS spoofing jammers is only slightly higher than that of genuine GNSS signals, GNSS spoofing jammers are highly concealed. Monitoring and locating the sources of GNSS spoofing jammers is a crucial and effective means of countering GNSS spoofing jammers.

[0005] Space-based monitoring and positioning of GNSS deceptive interference sources offers significant advantages, including all-weather and global coverage, and is currently a research focus. Dual-satellite-based space-based monitoring and positioning of GNSS deceptive interference sources is a viable solution, offering high positioning accuracy and a simple system architecture. However, tracking GNSS deceptive interference using dual satellites remains a pressing issue. Summary of the Invention

[0006] The purpose of this invention is to provide a dual-satellite GNSS deceptive jamming tracking method and system. This method and system can be applied to dual-satellite monitoring and positioning systems, providing an effective solution to the current problem of dual-satellite GNSS deceptive jamming tracking.

[0007] To achieve the above objectives, this application proposes a dual-satellite-based GNSS deceptive jamming tracking method, including:

[0008] Step S101) When GNSS deceptive interference transmitted by the same GNSS deceptive interference source is respectively propagated to two satellites, relevant operations are performed on the GNSS deceptive interference received by the two satellites;

[0009] Step S102) performing a short-time coherent integration operation on the GNSS deceptive jamming correlation results;

[0010] Step S103) performing fast Fourier transform on the short-time coherent integration result;

[0011] Step S104) treating multiple consecutive fast Fourier transform results as a group and performing a non-coherent integration operation;

[0012] Step S105) finding the maximum value from the incoherent integration operation results;

[0013] Step S106) using a set threshold to determine the maximum value, if the maximum value is greater than or equal to the set threshold, the tracking channel can be configured, otherwise the tracking channel cannot be configured;

[0014] Step S107) When the tracking channel is configurable, the tracking channel is configured based on the delay time corresponding to the maximum value and the spectral line number of the fast Fourier transform;

[0015] Step S108) Repeat steps S101) to S107) to obtain a sequence of delay time and fast Fourier transform number combinations, which is the GNSS deceptive interference tracking result based on the dual-star system.

[0016] As an improvement to the above method, step S101) includes:

[0017] The correlation expression of GNSS deceptive jamming based on dual satellites is:

[0018]

[0019] Where R(t,τ) represents the correlation result of GNSS deceptive jamming; t represents time; τ represents time delay, and -0.5ms≤τ≤0.5ms; the superscript * represents the conjugate operation; r1(t) represents the GNSS deceptive jamming received by the first satellite.

[0020] As an improvement to the above method, step S102) includes:

[0021] The short-time coherent integration operation is expressed as:

[0022]

[0023] Wherein, n represents the short-time coherent integration ordinal number, n ≥ 0; T represents the short-time coherent integration time; S represents the short-time coherent integration result; S(n,τ) represents the nth short-time coherent integration result at τ.

[0024] As an improvement to the above method, step S103) includes:

[0025] Every N consecutive short-time coherent integration results S(n,τ) are taken as a group and subjected to fast Fourier transform operation, which is expressed as:

[0026]

[0027] Wherein, u represents the u-th fast Fourier transform, u≥0; v represents the v-th spectral line corresponding to the fast Fourier transform, 0≤v≤(N-1); F represents the fast Fourier transform result; F(τ,v,u) represents the value corresponding to the u-th fast Fourier transform operation at (τ,v).

[0028] As an improvement to the above method, step S104) includes:

[0029] The U consecutive fast Fourier transform results F(τ,v,u) are taken as a group and non-coherent integration operation is performed, which is expressed as:

[0030]

[0031] Where G(τ,v) represents the value corresponding to the incoherent integration operation at (τ,v).

[0032] As an improvement to the above method, step S105) includes:

[0033] Determine the maximum value expressed as:

[0034]

[0035] Wherein, max(·) represents the maximum value function; M represents the maximum value of the incoherent integration result; It represents the (τ, v) combination corresponding to the maximum value of the incoherent integration result.

[0036] As an improvement to the above method, step S107) includes:

[0037] After the configuration is completed, the tracking channel is expressed as follows based on the dual-satellite GNSS deceptive interference:

[0038]

[0039] Among them, -ε≤τ≤ε, ε represents the minimum value.

[0040] The present application also provides a dual-satellite-based GNSS deceptive jamming tracking system, which is implemented based on the above method and includes:

[0041] a coherent operation module, configured to perform a correlation operation on the GNSS deceptive interference received by the two satellites when the GNSS deceptive interference transmitted by the same GNSS deceptive interference source is respectively propagated to the two satellites;

[0042] A short-time coherent integration module is used to perform short-time coherent integration operations on GNSS deceptive interference correlation results;

[0043] A fast Fourier transform module, used for performing fast Fourier transform on the short-time coherent integration result;

[0044] A non-coherent integration module is used to treat multiple consecutive fast Fourier transform results as a group and perform non-coherent integration operations;

[0045] A maximum value search module is used to find the maximum value from the results of non-coherent integration operations;

[0046] A maximum value identification module is used to identify the maximum value using a set threshold;

[0047] A tracking channel configuration module is used to configure the tracking channel based on the delay time and the spectral line number of the fast Fourier transform corresponding to the maximum value when the tracking channel is configurable;

[0048] The loop module is used to call the above modules in sequence to obtain a sequence of delay time and fast Fourier spectrum line number combination, which is the GNSS deceptive interference tracking result based on the dual satellite.

[0049] Compared with the prior art, the advantages of this application are:

[0050] 1. The method proposed in this invention is applicable to a dual-satellite monitoring and positioning system, and provides an effective solution to the current problem of dual-satellite-based GNSS deceptive interference tracking.

[0051] 2. The method and system proposed in the present invention are simple, effective and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 FIG2 is a flow chart of a dual-satellite-based GNSS deceptive jamming tracking method;

[0053] Figure 2 The figure shows the structural block diagram of the dual-star-based GNSS deceptive jamming tracking system. DETAILED DESCRIPTION

[0054] The technical solution of this application is described in detail below with reference to the accompanying drawings.

[0055] like Figure 1 As shown, the present invention proposes a dual-star GNSS deceptive interference tracking method, comprising:

[0056] Step S101) GNSS deceptive jamming correlation.

[0057] Two satellites jointly observe the same area on the Earth's surface, which is called the joint observation area. When a GNSS spoofing interference source exists within the joint observation area and the GNSS spoofing interference emitted by this GNSS spoofing interference source can be received by both satellites simultaneously, GNSS spoofing interference capture based on the two satellites can be performed. For ease of description, the two satellites are denoted as Satellite 1 and Satellite 2. When the GNSS spoofing interference emitted by the same GNSS spoofing interference source propagates to Satellite 1 and Satellite 2 respectively, the GNSS spoofing interference received by Satellite 1 is denoted as r1(t), and the GNSS spoofing interference received by Satellite 2 is denoted as r2(t). Where t represents time in seconds.

[0058] The correlation expression of GNSS deceptive jamming based on dual satellites is:

[0059]

[0060] Where R(t,τ) represents the GNSS deceptive jamming correlation result; τ represents the time delay in seconds, and -0.5ms≤τ≤0.5ms; the superscript * indicates the conjugate operation.

[0061] Step S102) Short-time coherent integration.

[0062] Based on the GNSS deceptive jamming correlation result R(t,τ), a short-time coherent integration operation is performed, which is expressed as:

[0063]

[0064] Wherein, n represents the short-time coherent integration number, and n≥0; T represents the short-time coherent integration time, in seconds; S represents the short-time coherent integration result, and S(n,τ) represents the nth short-time coherent integration result at τ.

[0065] Step S103) FFT operation.

[0066] Every N consecutive short-time coherent integration results S(n,τ) are taken as a group and FFT operation is performed, which is expressed as:

[0067]

[0068] Among them, u represents the u-th FFT operation, and u ≥ 0; v represents the v-th spectral line corresponding to the FFT operation, and 0 ≤ v ≤ (N - 1); F represents the FFT operation result, and F(τ, v, u) represents the value corresponding to the u-th FFT operation at (τ, v).

[0069] Step S104) Non-coherent integration.

[0070] Taking the U consecutive FFT operation results F(τ, v, u) as a group for non-coherent integration operation, which is expressed as:

[0071]

[0072] Among them, G represents the non-coherent integration result, and G(τ, v) represents the value corresponding to the non-coherent integration operation at (τ, v).

[0073] Step S105) Determine the maximum value.

[0074] The non-coherent integration result G obtained from the non-coherent integration operation is a two-dimensional matrix, and different (τ, v) combinations correspond to different values, and there is a maximum value in this two-dimensional matrix. Determining the maximum value is expressed as:

[0075]

[0076] Among them, max(·) represents the maximum value taking function; M represents the maximum value of the non-coherent integration result G; represents the (τ, v) combination corresponding to the maximum value of the non-coherent integration result G.

[0077] Step S106) Maximum value judgment. [[ID=3`1]]

[0078] Th represents the judgment threshold (empirical value). When M ≥ Th, it indicates that the tracking condition is satisfied and the tracking channel can be configured. When M < Th, it indicates that the tracking condition is not satisfied and the tracking channel cannot be configured or the tracking ends.

[0079] Step S107) Configure the tracking channel.

[0080] Based on the (τ, v) combination corresponding to the maximum value of the non-coherent integration result G Configure the tracking channel. After the configuration is completed, the tracking channel is related to the GNSS spoofing interference of the double stars as:

[0081]

[0082] Among them, -ε ≤ τ ≤ ε, and ε represents a very small value with the unit of "second".[[ID=4`7]]

[0083] Step S108) Output the tracking result.

[0084] Repeat steps S101) to S107) to obtain a The sequence is the real-time tracking result of GNSS deceptive interference based on dual stars.

[0085] like Figure 2 As shown, the present application also provides a dual-star-based GNSS deceptive jamming tracking system, which is implemented based on the above method and includes:

[0086] a coherent operation module, configured to perform a correlation operation on the GNSS deceptive interference received by the two satellites when the GNSS deceptive interference transmitted by the same GNSS deceptive interference source is respectively propagated to the two satellites;

[0087] A short-time coherent integration module is used to perform short-time coherent integration operations on GNSS deceptive interference correlation results;

[0088] A fast Fourier transform module, used for performing fast Fourier transform on the short-time coherent integration result;

[0089] A non-coherent integration module is used to treat multiple consecutive fast Fourier transform results as a group and perform non-coherent integration operations;

[0090] A maximum value search module is used to find the maximum value from the results of non-coherent integration operations;

[0091] A maximum value identification module is used to identify the maximum value using a set threshold;

[0092] A tracking channel configuration module is used to configure the tracking channel based on the delay time and the spectral line number of the fast Fourier transform corresponding to the maximum value when the tracking channel is configurable;

[0093] The loop module is used to call the above modules in sequence to obtain a sequence of delay time and fast Fourier spectrum line number combination, which is the GNSS deceptive interference tracking result based on the dual satellite.

[0094] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit the scope of the present invention. Although this application has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application and should be encompassed by the claims of this application.

Claims

1. A dual-satellite-based GNSS deceptive jamming tracking method, comprising: Step S101) When GNSS deceptive interference transmitted by the same GNSS deceptive interference source is respectively propagated to two satellites, relevant operations are performed on the GNSS deceptive interference received by the two satellites; Step S102) performing a short-time coherent integration operation on the GNSS deceptive jamming correlation results; Step S103) performing fast Fourier transform on the short-time coherent integration result; Step S104) treating multiple consecutive fast Fourier transform results as a group and performing a non-coherent integration operation; Step S105) finding the maximum value from the incoherent integration operation results; Step S106) using a set threshold to determine the maximum value, if the maximum value is greater than or equal to the set threshold, the tracking channel can be configured, otherwise the tracking channel cannot be configured; Step S107) When the tracking channel is configurable, the tracking channel is configured based on the delay time corresponding to the maximum value and the spectral line number of the fast Fourier transform; Step S108) Repeat steps S101) to S107) to obtain a sequence of delay time and fast Fourier transform number combinations, which is the GNSS deceptive interference tracking result based on the dual-star system.

2. The dual-star GNSS deceptive jamming tracking method according to claim 1, characterized in that: The step S101) includes: The correlation expression of GNSS deceptive jamming based on dual satellites is: Where R(t,τ) represents the correlation result of GNSS deceptive jamming; t represents time; τ represents time delay, and -0.5ms≤τ≤0.5ms; the superscript * represents the conjugate operation; r1(t) represents the GNSS deceptive jamming received by the first satellite.

3. The dual-star GNSS deceptive jamming tracking method according to claim 2, characterized in that: The step S102) includes: The short-time coherent integration operation is expressed as: Wherein, n represents the short-time coherent integration ordinal number, n ≥ 0; T represents the short-time coherent integration time; S represents the short-time coherent integration result; S(n,τ) represents the nth short-time coherent integration result at τ.

4. The dual-star GNSS deceptive jamming tracking method according to claim 3, characterized in that: The step S103) includes: Every N consecutive short-time coherent integration results S(n,τ) are taken as a group and subjected to fast Fourier transform operation, which is expressed as: Wherein, u represents the u-th fast Fourier transform, u≥0; v represents the v-th spectral line corresponding to the fast Fourier transform, 0≤v≤(N-1); F represents the fast Fourier transform result; F(τ,v,u) represents the value corresponding to the u-th fast Fourier transform operation at (τ,v).

5. The dual-star GNSS deceptive jamming tracking method according to claim 4, characterized in that: The step S104) includes: The U consecutive fast Fourier transform results F(τ,v,u) are taken as a group and non-coherent integration operation is performed, which is expressed as: Where G(τ,v) represents the value corresponding to the incoherent integration operation at (τ,v).

6. The dual-star GNSS deceptive jamming tracking method according to claim 5, characterized in that: The step S105) includes: Determine the maximum value expressed as: Wherein, max(·) represents the maximum value function; M represents the maximum value of the incoherent integration result; It represents the (τ, v) combination corresponding to the maximum value of the incoherent integration result.

7. The dual-star GNSS deceptive jamming tracking method according to claim 6, characterized in that: The step S107) includes: After the configuration is completed, the tracking channel is expressed as follows based on the dual-satellite GNSS deceptive interference: Among them, -ε≤τ≤ε, ε represents the minimum value.

8. A dual-satellite-based GNSS deceptive jamming tracking system, implemented based on the method of any one of claims 1 to 7, characterized in that: The system comprises: a coherent operation module, configured to perform a correlation operation on the GNSS deceptive interference received by the two satellites when the GNSS deceptive interference transmitted by the same GNSS deceptive interference source is respectively propagated to the two satellites; A short-time coherent integration module is used to perform short-time coherent integration operations on GNSS deceptive interference correlation results; A fast Fourier transform module, used for performing fast Fourier transform on the short-time coherent integration result; A non-coherent integration module is used to treat multiple consecutive fast Fourier transform results as a group and perform non-coherent integration operations; A maximum value search module is used to find the maximum value from the results of non-coherent integration operations; A maximum value identification module is used to identify the maximum value using a set threshold; a configuration tracking channel module for configuring the tracking channel based on the delay time and the fast Fourier transform spectral line number corresponding to the maximum value when the tracking channel is configurable; and The loop module is used to call the above modules in sequence to obtain a sequence of delay time and fast Fourier spectrum line number combination, which is the GNSS deceptive interference tracking result based on the dual satellite.

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