GNSS deception jamming tracking method and system based on double satellites

Abstract

The invention provides a GNSS deception jamming tracking method and system based on double satellites, and the method comprises the steps: carrying out the related operation of deception jamming received by two satellites when the deception jamming transmitted by the same deception jamming source is transmitted to the two satellites; performing short-time coherent integration operation; carrying out fast Fourier transform; taking a plurality of continuous fast Fourier transform results as a group, and performing incoherent integral operation; finding out a maximum value; judging the maximum value by using a set threshold value; when the tracking channel can be configured, configuring the tracking channel based on the delay time corresponding to the maximum value and the spectral line ordinal number of the fast Fourier transform; and repeatedly executing the steps to obtain a sequence of combination of the delay time and the fast Fourier transform times, wherein the sequence is an interference tracking result. The method has the advantages that the method is suitable for a double-satellite monitoring and positioning system, and a solution is provided for solving the problem of current double-satellite-based GNSS deception 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 penetrated into all aspects of human life and has greatly changed people's production and lifestyle. GNSS-based applications and systems continue to emerge, serving economic development, scientific research, and national defense construction, playing a very important role.

[0003] The application of GNSS in the military field has been continuously expanded and deepened, leading to the increasing GNSS confrontation at the military level, and the inherent vulnerability of GNSS has also been exposed. The emergence of malicious GNSS interference represented by GNSS spoofing interference has greatly endangered the security of GNSS-based applications and systems. Therefore, GNSS spoofing interference monitoring technology and application has become one of the current research focuses.

[0004] GNSS spoofing jammers have the same modulation system as real GNSS signals, which can invade GNSS receivers and cause them to output incorrect position, velocity and time (PVT) information. Therefore, GNSS spoofing jammers are extremely threatening. In addition, the power of GNSS spoofing jammers is only slightly higher than that of real GNSS signals, so GNSS spoofing jammers are highly concealed. Monitoring and locating GNSS spoofing jammers that transmit GNSS spoofing jammers is one of the most important and effective means to deal with GNSS spoofing jammers.

[0005] GNSS deceptive interference source space-based monitoring and positioning has the significant advantages of all-weather and global coverage, and is the current research focus. Dual-satellite-based GNSS deceptive interference source space-based monitoring and positioning is a feasible GNSS deceptive interference source space-based monitoring and positioning solution, which has the advantages of high positioning accuracy and simple system composition. Among them, dual-satellite-based GNSS deceptive interference tracking has always been a problem that needs to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to propose a dual-star GNSS deceptive interference tracking method and system. The method and system can be applied to a dual-star monitoring and positioning system, providing an effective solution to the current problem of dual-star GNSS deceptive interference tracking.

[0007] In order to achieve the above objectives, the present application proposes a dual-star-based GNSS deceptive interference tracking method, comprising:

[0008] Step S101) when the GNSS deceptive interference emitted 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) taking a plurality of continuous 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 discriminate the maximum value, when 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, configuring the tracking channel based on the delay time corresponding to the maximum value and the spectral line number of the fast Fourier transform;

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

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

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

[0018]

[0019] Where R(t,τ) represents the GNSS deceptive jamming correlation result; t represents time; τ represents time delay, and -0.5ms≤τ≤0.5ms; the superscript * represents the conjugate operation; r 1 (t) represents the GNSS spoofing interference received by the first satellite.

[0020] As an improvement of the above method, the 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 of the above method, the 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 of the above method, the step S104) includes:

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

[0030]

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

[0032] As an improvement of the above method, the 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; Represents the (τ, v) combination corresponding to the maximum value of the incoherent integration result.

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

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

[0038]

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

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

[0041] A coherent operation module, used for performing a correlation operation on the GNSS deceptive interference received by the two satellites when the GNSS deceptive interference emitted 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 related 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, used for treating a plurality of continuous fast Fourier transform results as a group and performing non-coherent integration operation;

[0045] A maximum value search module is used to find the maximum value from the incoherent integration operation results;

[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 turn to obtain a sequence of delay time and fast Fourier spectral 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 the present invention is applicable to a dual-star monitoring and positioning system, and provides an effective solution to the current problem of dual-star-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 Shown is a flow chart of a dual-star based GNSS deceptive jamming tracking method;

[0053] Figure 2 Shown is the structural block diagram of the dual-star based GNSS deceptive interference tracking system. DETAILED DESCRIPTION

[0054] The technical solution of the present 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] The two satellites conduct joint observations on the same area on the earth's surface, which is called the joint observation area. When there is a GNSS deceptive interference source in the joint observation area and the GNSS deceptive interference emitted by the GNSS deceptive interference source can be received by the two satellites at the same time, the GNSS deceptive interference capture based on the two satellites can be performed. For the convenience of description, the two satellites are respectively recorded as satellite 1 and satellite 2. When the GNSS deceptive interference emitted by the same GNSS deceptive interference source is transmitted to satellite 1 and satellite 2 respectively, the GNSS deceptive interference received by satellite 1 is recorded as r 1 (t), the GNSS deceptive interference received by satellite 2 is denoted as r 2 (t). Wherein, t represents time, in seconds.

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

[0059]

[0060] Wherein, R(t,τ) represents the GNSS deceptive interference correlation result; τ represents the time delay, the unit is "second", and -0.5ms≤τ≤0.5ms; the superscript * represents the conjugate operation.

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

[0062] Based on the GNSS deceptive interference 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 ordinal number, and n≥0; T represents the short-time coherent integration time, and the unit is 'second'; 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 subjected to FFT operation, 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 result of the FFT operation, 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 U consecutive FFT operation results F(τ, v, u) as a group, perform 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. 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 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.

[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 follows:

[0081]

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

[0083] Step S108) Output the tracking results.

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

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

[0086] A coherent operation module, used for performing a correlation operation on the GNSS deceptive interference received by the two satellites when the GNSS deceptive interference emitted 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 related 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, used for treating a plurality of continuous fast Fourier transform results as a group and performing non-coherent integration operation;

[0090] A maximum value search module is used to find the maximum value from the incoherent integration operation results;

[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 turn to obtain a sequence of delay time and fast Fourier spectral 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 only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application is described in detail with reference to the embodiments, a person skilled in the art should understand that any modification or equivalent replacement of the technical solution of the present application does not depart from the spirit and scope of the technical solution of the present application and should be included in the scope of the claims of the present application.

Claims

1. A dual-star based GNSS deceptive jamming tracking method, comprising: Step S101) when the GNSS deceptive interference emitted 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) taking a plurality of continuous 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 discriminate the maximum value, when 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, configuring the tracking channel based on the delay time corresponding to the maximum value and the spectral line number of the fast Fourier transform; Step S108) repeats steps S101) to S107) to obtain a sequence of combinations of delay time and number of fast Fourier transforms, which is the GNSS deceptive interference tracking result based on dual satellites.

2. The dual-star GNSS deceptive interference tracking method according to claim 1 is characterized in that: The step S101) comprises: The correlation expression of GNSS deceptive jamming based on dual satellites is: Wherein, R(t,τ) represents the GNSS deceptive interference correlation result; 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 interference received by the first satellite.

3. The dual-star GNSS deceptive interference tracking method according to claim 2 is characterized in that: The step S102) comprises: 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 interference tracking method according to claim 3 is characterized in that: The step S103) comprises: 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 based GNSS deceptive interference tracking method according to claim 4, characterized in that: The step S104) comprises: The U consecutive fast Fourier transform operation results F(τ,v,u) are taken as a group and non-coherent integration operation is performed, which is expressed as: Among them, G(τ,v) represents the value corresponding to the incoherent integration operation at (τ,v).

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

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

8. A dual-star based GNSS deceptive jamming tracking system, implemented based on any of the methods described in claims 1-7, characterized in that: The system comprises: A coherent operation module, used for performing a correlation operation on the GNSS deceptive interference received by the two satellites when the GNSS deceptive interference emitted 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 related results; A fast Fourier transform module, used for performing fast Fourier transform on the short-time coherent integration result; A non-coherent integration module, used for treating a plurality of continuous fast Fourier transform results as a group and performing non-coherent integration operation; A maximum value search module is used to find the maximum value from the incoherent integration operation results; A maximum value identification module is used to identify the maximum value using a set threshold; 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; and The loop module is used to call the above modules in turn to obtain a sequence of delay time and fast Fourier spectral line number combination, which is the GNSS deceptive interference tracking result based on the dual satellite.

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