GNSS interference detection method and system based on AGC gain of satellite-borne GNSS occultation detector

Abstract

The invention provides a GNSS interference detection method and system based on AGC gain of a satellite-borne GNSS occultation detector. The method comprises the following steps: reading AGC gain data and LEO satellite position data; performing time matching on the AGC gain data and the LEO satellite position data; determining an AGC gain under the condition of no GNSS interference; calculating an AGC gain difference value sequence; and performing GNSS interference detection on the AGC gain difference value sequence based on a set GNSS interference detection threshold value. The method has the advantages that the method is suitable for the satellite-borne GNSS occultation detector, an effective solution is provided for carrying out GNSS interference detection based on the observed quantity of the satellite-borne GNSS occultation detector, and the method is simple, effective and convenient to implement.

Description

Technical Field

[0001] The present application belongs to the field of GNSS remote sensing technology and application and the field of GNSS interference monitoring technology and application, and specifically relates to a GNSS interference detection method and system based on the AGC gain of a satellite-borne GNSS occultation detector. Background Art

[0002] The Global Navigation Satellite System (GNSS) has greatly promoted economic and social development, promoted the progress of scientific research, helped the construction of national defense and the military, and changed people's lifestyles. With the rapid development and widespread application of GNSS, the inherent vulnerability of GNSS has also been exposed, and intentional and unintentional GNSS interference has also increased. In particular, the emergence of intentional GNSS interference has greatly endangered the security of GNSS-based applications and systems. Therefore, GNSS interference monitoring technology and application has become one of the current research focuses.

[0003] Space-based GNSS occultation remote sensing detection technology is a technology that uses the global navigation satellite system to conduct remote sensing detection of the Earth's atmosphere. Space-borne GNSS occultation detectors are payloads for space-based GNSS occultation remote sensing detection, and are usually carried on low Earth Orbit (LEO) satellites. It is worth mentioning that the occultation antenna equipped with the space-borne GNSS occultation detector is a right-hand circularly polarized high-gain antenna. While receiving GNSS occultation signals, it can also receive GNSS interference from the Earth's surface. These received GNSS interferences will inevitably affect the normal operation of the space-borne GNSS occultation detector and affect the measurement values ​​of various observation quantities.

[0004] In summary, GNSS interference detection based on space-borne GNSS occultation detector observations has always been one of the research hotspots. Summary of the invention

[0005] The purpose of the present invention is to propose a GNSS interference detection method based on the AGC gain of a satellite-borne GNSS occultation detector. The method can be applied to the satellite-borne GNSS occultation detector and provides an effective solution for GNSS interference detection based on the observations of the satellite-borne GNSS occultation detector.

[0006] In order to achieve the above objectives, the present application proposes a GNSS interference detection method based on the AGC gain of a satellite-borne GNSS occultation detector, comprising:

[0007] Step S101) reading AGC gain data;

[0008] Step S102) reading LEO satellite position data;

[0009] Step S103) time matching the AGC gain data with the LEO satellite position data;

[0010] Step S104) determining the AGC gain under the condition of no GNSS interference;

[0011] Step S105) calculating the AGC gain difference sequence;

[0012] Step S106) performing GNSS interference detection on the AGC gain difference sequence based on the set GNSS interference detection threshold.

[0013] As an improvement of the above method, the step S104) includes:

[0014] The South Pacific region is regarded as a region without GNSS interference, and the LEO satellite positions of all sub-satellite points in the South Pacific region are composed of a set {P s}, set {P s}satisfy:

[0015]

[0016] Where i represents the ordinal number of the LEO satellite position sequence; P(i) represents the i-th element in the LEO satellite position sequence P; mathematical symbols represents any; Lon represents longitude; Lat represents latitude;

[0017] With the set {P s The corresponding AGC gain composition set {G s}; The AGC gain without GNSS interference is expressed as:

[0018] G0=mean({G s})

[0019] Where G0 represents the AGC gain without GNSS interference; mean(·) represents the function of taking the average value of all elements.

[0020] As an improvement of the above method, the step S105) includes:

[0021] Based on the AGC gain sequence G and the AGC gain G0 under the condition of no GNSS interference, the AGC gain difference sequence is calculated, which is expressed as:

[0022] ΔG=[ΔG(1),ΔG(2),ΔG(3),…,ΔG(n),…,ΔG(N)]

[0023] Wherein, ΔG represents the AGC gain difference sequence; ΔG(n) represents the nth element in the AGC gain difference sequence, and ΔG(n)=G(n)-G0.

[0024] As an improvement of the above method, the step S106) includes:

[0025] Based on the AGC gain difference sequence ΔG, when ΔG(n)≤Th, it is determined that the LEO satellite has received GNSS interference at position P(n); when ΔG(n)>Th / 2, it is determined that the LEO satellite has not received GNSS interference at position P(n); when Th<ΔG(n)≤Th / 2, it is determined that the LEO satellite is suspected of receiving GNSS interference at position P(n); Th represents the set GNSS interference detection threshold.

[0026] The present application also provides a GNSS interference detection system based on the AGC gain of a satellite-borne GNSS occultation detector, which is implemented based on the above method, and the system includes:

[0027] The gain data reading module is used to read the AGC gain data;

[0028] The satellite position data reading module is used to read the LEO satellite position data;

[0029] A time matching module is used to time match the AGC gain data with the LEO satellite position data;

[0030] An interference-free gain determination module is used to determine the AGC gain under the condition of no GNSS interference;

[0031] A gain difference sequence calculation module is used to calculate the AGC gain difference sequence;

[0032] The interference detection module is used to perform GNSS interference detection on the AGC gain difference sequence according to a set GNSS interference detection threshold.

[0033] Compared with the prior art, the advantages of this application are:

[0034] 1. The method proposed in the present invention is applicable to a space-borne GNSS occultation detector, and provides an effective solution for GNSS interference detection based on the observations of the space-borne GNSS occultation detector;

[0035] 2. The method proposed in the present invention is simple, effective and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Shown is a flow chart of a GNSS interference detection method based on the AGC gain of a space-borne GNSS occultation detector. DETAILED DESCRIPTION

[0037] The technical solution of the present application is described in detail below with reference to the accompanying drawings.

[0038] like Figure 1 As shown, the present invention proposes a GNSS interference detection method based on the AGC gain of a satellite-borne GNSS occultation detector, comprising:

[0039] Step S101) reading AGC gain data;

[0040] Generally, the RF unit of a satellite-borne GNSS occultation detector contains an AGC module, which is used to autonomously adjust the RF front-end gain, thereby ensuring that the strength of the signal input to the subsequent ADC is in a suitable range, thereby ensuring the normal operation of the satellite-borne GNSS occultation detector. The gain of the AGC module contained in the RF unit is called the AGC gain. The host of the satellite-borne GNSS occultation detector reads the AGC gain in real time according to a certain frequency. G(t) represents the real-time read AGC gain, in "dB", where t represents time, in "seconds".

[0041] Step S102) reading LEO satellite position data;

[0042] A spaceborne GNSS occultation detector usually includes a spaceborne GNSS receiver module. The spaceborne GNSS receiver module is responsible for processing GNSS signals and performing positioning calculations to obtain the position information of the LEO satellite platform where the spaceborne GNSS occultation detector is located. The host of the spaceborne GNSS occultation detector reads the LEO satellite position information in real time at a certain frequency. P(t) represents the real-time read LEO satellite position information.

[0043] Step S103) Time matching of AGC gain data and LEO satellite position data;

[0044] Based on the real-time read AGC gain G(t) and the real-time read LEO satellite position P(t), the AGC gain data and the LEO satellite position data are matched. The matching operation matches the AGC gain and the LEO satellite position read at the same time one by one, and obtains the AGC gain sequence and the LEO satellite position sequence respectively.

[0045] The one-to-one correspondence between the AGC gain sequence and the LEO satellite position sequence is expressed as:

[0046]

[0047] Where G represents the AGC gain sequence; P represents the LEO satellite position sequence; n represents the sequence number; N represents the total number of elements; G(n) represents the nth element in the AGC gain sequence; P(n) represents the nth element in the LEO satellite position sequence, and P(n) = [Lon(n), Lat(n), Alt(n)] T ; Where Lon represents longitude, Lat represents latitude, and Alt represents altitude. The superscript T represents transposition.

[0048] Step S104) determining the AGC gain under the condition of no GNSS interference;

[0049] Generally, the South Pacific region (170°W to 90°W, 60°S to 10°S) is far from the mainland, sparsely populated, and GNSS interference rarely occurs. Therefore, the South Pacific region is regarded as a GNSS interference-free region. The LEO satellite positions of all sub-satellite points in the South Pacific region form a set {P s}, set {P s}satisfy:

[0050]

[0051] Where i represents the ordinal number of the LEO satellite position sequence, and P(i) represents the i-th element in the LEO satellite position sequence P; mathematical symbols Indicates any.

[0052] With the set {P s The corresponding AGC gain composition set {G s}. The AGC gain without GNSS interference is expressed as:

[0053] G0=mean({G s}) (3)

[0054] Where G0 represents the AGC gain without GNSS interference; mean(-) represents the function of taking the average value of all elements.

[0055] Step S105) calculating the AGC gain difference sequence;

[0056] Based on the AGC gain sequence G and the AGC gain G0 under the condition of no GNSS interference, the AGC gain difference sequence is calculated, which is expressed as:

[0057] ΔG=G-G0=[ΔG(1),ΔG(2),ΔG(3),…,ΔG(n),…,ΔG(N)] (4)

[0058] Wherein, ΔG represents the AGC gain difference sequence; ΔG(n) represents the nth element in the AGC gain difference sequence, and ΔG(n)=G(n)-G0.

[0059] Step S106) GNSS interference detection;

[0060] Based on the AGC gain difference sequence ΔG, when ΔG(n)≤Th, it is determined that the LEO satellite has received GNSS interference at position P(n); when ΔG(n)>Th / 2, it is determined that the LEO satellite has not received GNSS interference at position P(n); when Th<ΔG(n)≤Th / 2, it is determined that the LEO satellite is suspected of receiving GNSS interference at position P(n). Th represents the GNSS interference detection threshold, which is generally an empirical value in dB.

[0061] The present application also provides a GNSS interference detection system based on the AGC gain of a satellite-borne GNSS occultation detector, which is implemented based on the above method, and the system includes:

[0062] The gain data reading module is used to read the AGC gain data;

[0063] The satellite position data reading module is used to read the LEO satellite position data;

[0064] A time matching module is used to time match the AGC gain data with the LEO satellite position data;

[0065] An interference-free gain determination module is used to determine the AGC gain under the condition of no GNSS interference;

[0066] A gain difference sequence calculation module is used to calculate the AGC gain difference sequence;

[0067] The interference detection module is used to perform GNSS interference detection on the AGC gain difference sequence according to a set GNSS interference detection threshold.

[0068] 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 GNSS interference detection method based on AGC gain of a space-borne GNSS occultation detector, comprising: Step S101) reading AGC gain data; Step S102) reading LEO satellite position data; Step S103) time matching the AGC gain data with the LEO satellite position data; Step S104) determining the AGC gain under the condition of no GNSS interference; Step S105) calculating the AGC gain difference sequence; Step S106) performing GNSS interference detection on the AGC gain difference sequence based on the set GNSS interference detection threshold.

2. The GNSS interference detection method based on the AGC gain of the space-borne GNSS occultation detector according to claim 1, characterized in that: The step S104) comprises: The South Pacific region is regarded as a region without GNSS interference, and the LEO satellite positions of all sub-satellite points in the South Pacific region are composed of a set {P s }, set {P s }satisfy: Where i represents the ordinal number of the LEO satellite position sequence; P(i) represents the i-th element in the LEO satellite position sequence P; mathematical symbols represents any; Lon represents longitude; Lat represents latitude; With the set {P s The corresponding AGC gain composition set {G s }; The AGC gain without GNSS interference is expressed as: G0=mean({G s }) Where G0 represents the AGC gain without GNSS interference; mean(·) represents the function of taking the average value of all elements.

3. The GNSS interference detection method based on the AGC gain of the space-borne GNSS occultation detector according to claim 1 is characterized in that: The step S105) comprises: Based on the AGC gain sequence G and the AGC gain G0 under the condition of no GNSS interference, the AGC gain difference sequence is calculated, which is expressed as: ΔG=[ΔG(1),ΔG(2),ΔG(3),…,ΔG(n),…,ΔG(N)] Wherein, ΔG represents the AGC gain difference sequence; ΔG(n) represents the nth element in the AGC gain difference sequence, and ΔG(n)=G(n)-G0.

4. The GNSS interference detection method based on the AGC gain of the space-borne GNSS occultation detector according to claim 1, characterized in that: The step S106) comprises: Based on the AGC gain difference sequence ΔG, when ΔG(n)≤Th, it is determined that the LEO satellite has received GNSS interference at position P(n); when ΔG(n)>Th / 2, it is determined that the LEO satellite has not received GNSS interference at position P(n); when Th<ΔG(n)≤Th / 2, it is determined that the LEO satellite is suspected of receiving GNSS interference at position P(n); Th represents the set GNSS interference detection threshold.

5. A GNSS interference detection system based on AGC gain of a satellite-borne GNSS occultation detector, implemented based on the method described in any one of claims 1 to 4, characterized in that: The system comprises: The gain data reading module is used to read the AGC gain data; The satellite position data reading module is used to read the LEO satellite position data; A time matching module is used to time match the AGC gain data with the LEO satellite position data; An interference-free gain determination module is used to determine the AGC gain under the condition of no GNSS interference; A gain difference sequence calculation module, used for calculating an AGC gain difference sequence; and The interference detection module is used to perform GNSS interference detection on the AGC gain difference sequence according to a set GNSS interference detection threshold.

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