Method for estimating position of interference source

Abstract

The invention discloses a method for estimating the position of an interference source, which comprises the following steps of: firstly, confirming the direction of an antenna on a receiver, defining the relative position of a ground interference element and the receiver, and obtaining the gain of the receiving antenna in the BDS interference signal direction of the receiver according to a Haversin formula and coordinate transformation; and then performing gridding segmentation processing on the geographic area, assuming that the interference source is located at one grid point position of the geographic area, estimating the strength of the received interference signal according to the acquired data, and assuming whether the judgment criterion is true or not by using a judgment criterion, thereby determining the position of the interference source at a certain grid point in the geographic area. According to the method, the space search of the interference source in the geographic area is converted into the grid search, so that the interference source position estimation efficiency is greatly improved, and the accuracy of the estimation result is high.

Description

Technical Field

[0001] The invention relates to the technical field of satellite navigation, and in particular to a method for estimating the position of an interference source. Background Art

[0002] The Global Satellite Navigation System (GNSS) is an air-based radio navigation and positioning system that can provide users with all-weather three-dimensional coordinates, speed and time information at any location on the Earth's surface or in near-Earth space. It includes one or more satellite constellations and their augmentation systems required to support specific tasks. The four major satellite navigation system suppliers announced by the International Committee on Global Navigation Satellite Systems include the United States' Global Positioning System GPS, Russia's GLONASS, the European Union's Galileo Satellite Navigation System (GALILEO) and China's BeiDou Satellite Navigation System (BDS).

[0003] BDS jammer, also known as Beidou jammer or Beidou signal blocker, is an electronic device specially designed to interfere with or block the reception of BeiDou Navigation Satellite System (BDS) signals. BeiDou Navigation Satellite System is a global satellite navigation system independently developed by China, similar to the US GPS system, Russia's GLONASS system and Europe's Galileo system. BDS jammers emit electromagnetic waves similar to Beidou satellite signals, making it impossible for receiving equipment (such as navigation devices on vehicles, ships, and aircraft) to correctly receive or process valid signals from Beidou satellites, thereby affecting the positioning, navigation and time synchronization functions of these devices. The effect of interference depends on the power, operating frequency, design complexity and anti-interference ability of the target receiving equipment of the jammer. Since the Beidou system and the GPS system may overlap in some frequency bands, some BDS jammers may have a certain impact on GPS signals while interfering with Beidou signals.

[0004] The interference encountered by the BDS system can be divided into two categories: suppressive interference and deceptive interference, both of which can cause the receiver to be unable to receive and analyze the BDS signal normally. Specifically, suppressive interference is to transmit high-power frequency-modulated noise or modulated pseudo-random code with the same frequency as the BDS band through the jammer, resulting in a decrease in the signal-to-noise ratio of the BDS receiver, making the effective BDS signal drowned by the noise and indistinguishable. On the other hand, deceptive interference is to transmit fake BDS signals, inducing the BDS receiver to mistake these forged signals for real BDS signals and process them, resulting in distortion of the received geographic location information and presenting it as false data. Among them, deceptive interference is often used in navigation operations or navigation confrontation scenarios, and its purpose is to confuse the opponent's positioning judgment by providing a false signal source. In contrast, when performing missions, aerial vehicles are more likely to face suppressive interference from competing signal sources on the ground or in the same airspace. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for estimating the position of an interference source. By making assumptions about the position of each grid point of the interference source and then determining the grid point position of the interference source according to the interference signal strength of the receiver, it helps to transform the complex spatial search problem into a discretized grid search problem, and can more effectively process and analyze data, thereby improving estimation efficiency.

[0006] The technical solution of the present invention is:

[0007] A method for estimating the location of an interference source comprises the following steps:

[0008] (1) Confirm the direction of the antenna on the receiver, define the relative position of the ground interference element and the receiver, and obtain the receiving antenna gain in the direction of the receiver BDS interference signal based on the Haversin formula and coordinate transformation;

[0009] (2) The geographical area is divided into grids and the interference source is assumed to be located at one of the grid points in the geographical area. The strength of the received interference signal is estimated based on the collected data and the judgment criteria are used to determine whether the assumption is valid, thereby determining whether the interference source is located at a certain grid point in the geographical area.

[0010] The specific steps of confirming the direction of the antenna on the receiver, defining the relative position of the ground interference element and the receiver, and obtaining the receiving antenna gain in the direction of the receiver BDS interference signal according to the Haversin formula and coordinate transformation are as follows:

[0011] S11. Collect the receiver location data and define the coordinates of the ground interference source as (lat Jam ,lon Jam ,0), the coordinates of the receiver are (lat p,lon p ,hei p );

[0012] Based on the Haversine formula, that is, the following formula (1):

[0013]

[0014] Obtain the interference source ground point (lat Jam ,lon Jam ,0) to the receiver ground point (lat p ,lon p ,0), as shown in the following formula (2):

[0015] d0=Rhsin -1 (hsin(φ2-φ1))+cosφ1cosφ2hsin(λ2-λ1) (2);

[0016] In formula (2), R is the radius of the earth, φ2 is the latitude of the interference source, φ1 is the latitude of the receiver, λ2 is the longitude of the interference source, and λ1 is the longitude of the receiver;

[0017] S12. Defined in the three-dimensional coordinate system, the angle θ between the projection of the receiver antenna pointing to the ground and the positive direction of the z-axis is calculated by the following formula (3):

[0018]

[0019] The moving direction of the receiver is defined as heading, the angle between the projection of the receiver-antenna system on the ground and the true north direction is φ, and the angle between the projection of the receiver antenna on the ground and the true north direction is φ0;

[0020] The angle φ0 is calculated by the following formula (4):

[0021]

[0022] In formula (5), φ2 is the latitude of the interference source, φ1 is the latitude of the receiver, and Δλ represents the longitude difference between the receiver and the interference source coordinate point, that is, Δλ = |λ2-λ1|;

[0023] The angle φ is calculated by the following formula (5):

[0024] φ=heading-φ0 (5);

[0025] When the receiver has complex azimuth changes, the azimuth is φ, the yaw angle is heading, then the direction vector corresponding to φ0 is The position in the receiver coordinate system is in Satisfies the following formula (6):

[0026]

[0027] Formula (6) is expanded to obtain the matrix equation shown in formula (7):

[0028]

[0029] The ground coordinate system is transformed into the receiver coordinate system by performing three rotation transformations according to formula (7);

[0030] In formula (7), ψ is the X coordinate system of the receiver b Axis in ground coordinate system O e X e Y e Projection in the plane and X e The angle between the two axes; σ is the X b Axis and ground coordinate system O e X e Y e The angle between the planes; γ is the Y coordinate system of the receiver b Axis and ground coordinate system O e X e X e The angle between the planes;

[0031] Then according to the above formula (7), the direction vector After changing to the receiver coordinate system, (σ, ψ) is obtained; then the receiving antenna gain gain(σ, ψ) in the corresponding direction is obtained according to the following formula (8):

[0032]

[0033] In formula (8), σ c , σ f , ψ c , ψ f Satisfies the following formula (9):

[0034]

[0035] In formula (9), ceil() means rounding up, and floor() means rounding down.

[0036] The aforementioned grid-segmentation processing of the geographical area is performed, assuming that the interference source is located at one of the grid points in the geographical area, and then estimating the strength of the received interference signal based on the collected data, and using the judgment criteria to determine whether the assumption is established, thereby determining that the interference source is located at a certain grid point in the geographical area. The specific steps are:

[0037] S21, the edge node falls on a circle with the interference source as the center and the farthest interference distance as the radius, and the interference signal strength sent by the interference source to the edge node is threshold, then the interference signal strength threshold is the threshold;

[0038] S22, define that the mobile receiver receives the interference signal for the first time at time s during the movement process, that is, the interference signal strength received at this time is threshold, and is no longer interfered at time e+1. Based on the interference model, the receiver is an edge node of the interference model at time s and time e, and the received interference signal strength is approximately equal to threshold, that is, it satisfies the following formula (10):

[0039] P rs ,P re ∈[threshold-0.5Δ,threshold+0.5Δ] (10);

[0040] In formula (10), P rs is the interference signal strength received by the receiver at time s, P re is the interference signal strength received by the receiver at time e, and Δ is the error value;

[0041] The calculation formula for the interference signal strength received by the receiver is shown in the following formula (11):

[0042]

[0043] In formula (11), P t is the interference signal strength emitted by the interference source, G t is the gain of the interference source transmitting antenna, G rs is the receiving antenna gain of the receiver at time s, G re is the receiving antenna gain of the receiver at time e, G rs and G re Calculated by formula (8), λ is the wavelength of the interference signal, d is the distance between the receiver and the interference source, α is the environmental parameter, L is the loss factor of the receiver, L≥1;

[0044] S23. Solve the location (x, y, 0) of the interference source in the geographical area with longitude range [x0, x1] and latitude range [y0, y1], and define the location of the i-th grid point in the geographical area as (x i ,y i ,0),x i ∈[x0,x0+Δx,…,x1],y i ∈[y0,y0+Δy,…,y1], Δx and Δy represent the division interval values ​​of longitude and latitude when the geographical area is gridded;

[0045] Assume x = x i , y=y i , and then solve P according to formula (11) rs or P re , when the obtained P rs or P re If equation (10) is not satisfied, then the position of the i-th grid point is not the position of the interference source. rs or P re If equation (10) is satisfied, the position of the i-th grid point is taken as the assumed position of the interference source.

[0046] The method for setting the threshold value threshold and the error value Δ is as follows: first, fix Δ and traverse threshold: for each set threshold value, determine whether all receivers meet the condition according to formula (10). If so, set the flag value corresponding to the receiver to 1, otherwise to 0. Finally, record the number of receivers res with a flag value of 1, and determine the thershold value corresponding to the maximum res as the optimal threshold; then fix the thershold value, traverse all set Δ, and for each Δ value, check whether all receivers meet formula (10). If so, set the flag value corresponding to the receiver to 1. Finally, record the number of receivers res with a flag value of 1, and determine the Δ value corresponding to the maximum res as the optimal error value.

[0047] The i-th grid point is the interference source location, and the result set of its flag value is {flag i1 ,flag i2 ,…,flag iN}, N is the total number of receivers. In the result set, the number of receivers with flag value equal to 1 is: Δ i and threshold i Respectively represent the optimal error value and optimal threshold corresponding to the i-th grid point, res i The larger it is, the greater the possibility that the i-th grid point is the location of the interference source;

[0048] For all grid point positions, the feature set of all grid points is calculated, as shown in the following formula (12):

[0049] {(res i ,Δ i ,threshold i )},1≤i≤M×M (12);

[0050] In formula (12), M×M is the total number of grid points;

[0051] The probability value is then used to quantify the possibility that the i-th grid point is the location of the interference source. For the location of the i-th grid point, the probability value is used It indicates the possibility that the location is the interference source location. The grid point corresponding to the maximum P(i) value is the location of the interference source.

[0052] Advantages of the present invention:

[0053] The present invention obtains the receiving antenna gain in the direction of the interference signal, then performs grid division processing on the geographical area, and assumes that the interference source is located at one of the grid points, and then estimates the interference signal strength of the interference signal received by the receiver based on the collected data, and then determines whether the assumption is established based on a judgment criterion, thereby determining the location of the interference source, and converting the spatial search for the interference source in the geographical area into a grid search, which greatly improves the efficiency of the interference source position estimation, and the estimation result has a high accuracy rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a flow chart of the present invention.

[0055] Figure 2 It is the interference model diagram of the present invention.

[0056] Figure 3 It is a schematic diagram of the angular relationship among the yaw angle heading, the azimuth angle φ and the azimuth angle φ0 of the mobile receiver of the present invention.

[0057] Figure 4 It is a structural schematic diagram of the receiver coordinate system and the ground coordinate system of the present invention. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] See Figure 1 , a method for estimating the location of an interference source, specifically comprising the following steps:

[0060] (1) Confirm the direction of the antenna on the receiver, define the relative position of the ground interference element and the receiver, and obtain the receiving antenna gain in the direction of the receiver BDS interference signal based on the Haversin formula and coordinate transformation. The specific steps are as follows:

[0061] S11. Collect the receiver location data and define the coordinates of the ground interference source as (lat Jam,lon Jam ,0), the coordinates of the receiver are (lat p ,lon p ,hei p );

[0062] Based on the Haversine formula, that is, the following formula (1):

[0063]

[0064] Obtain the interference source ground point (lat Jam ,lon Jam ,0) to the receiver ground point (lat p ,lon p ,0), as shown in the following formula (2):

[0065] d0=Rhsin -1 (hsin(φ2-φ1))+cosφ1cosφ2hsin(λ2-λ1) (2);

[0066] In formula (2), R is the radius of the earth, φ2 is the latitude of the interference source, φ1 is the latitude of the receiver, λ2 is the longitude of the interference source, and λ1 is the longitude of the receiver;

[0067] If the distance of the great circle on the earth's surface is approximated as the straight-line distance, then the interference source (lat Jam ,long Jam ,0) to the receiver (lat p ,lon p ,hei p )

[0068] S12. Defined in the three-dimensional coordinate system, the angle θ between the projection of the receiver antenna pointing to the ground and the positive direction of the z-axis is calculated by the following formula (3):

[0069]

[0070] See Figure 3 , define the moving direction of the receiver as heading, the angle between the projection of the receiver-antenna system on the ground and the true north direction as φ, and the angle between the projection of the receiver antenna pointing to the ground and the true north direction as φ0;

[0071] The angle φ0 is calculated by the following formula (4):

[0072]

[0073] In formula (5), φ2 is the latitude of the interference source, φ1 is the latitude of the receiver, and Δλ represents the longitude difference between the receiver and the interference source coordinate point, that is, Δλ = |λ2-λ1|;

[0074] The angle φ is calculated by the following formula (5):

[0075] φ=heading-φ0 (5);

[0076] When the receiver has complex azimuth changes, the azimuth is φ, the yaw angle is heading, then the direction vector corresponding to φ0 is The position in the receiver coordinate system is in Satisfies the following formula (6):

[0077]

[0078] Formula (6) is expanded to obtain the matrix equation shown in formula (7):

[0079]

[0080] The ground coordinate system is transformed into the receiver coordinate system by performing three rotation transformations according to formula (7);

[0081] In formula (7), ψ is the X coordinate system of the receiver b Axis in ground coordinate system O e X e Y e Projection in the plane and X e The angle between the two axes; σ is the X b Axis and ground coordinate system O e X e Y e The angle between the planes; γ is the Y coordinate system of the receiver b Axis and ground coordinate system O e X e Y e The angle between the planes is shown in Figure 4 As shown;

[0082] Then according to the above formula (7), the direction vector After changing to the receiver coordinate system, (σ, ψ) is obtained; then the receiving antenna gain gain(σ, ψ) in the corresponding direction is obtained according to the following formula (8):

[0083]

[0084] In formula (8), σ c , σ f , ψ c , ψf Satisfies the following formula (9):

[0085]

[0086] In formula (9), ceil() means rounding up, and floor() means rounding down;

[0087] (2) The geographical area is divided into grids, and it is assumed that the interference source is located at one of the grid points in the geographical area. Then, the strength of the received interference signal is estimated based on the collected data. The judgment criterion assumption is used to determine whether the interference source is located at a certain grid point in the geographical area. The specific steps are as follows:

[0088] S21, see Figure 2 In the interference model, the interference signal emitted by the interference source has the same power in all directions, and reaches the receiver through the line-of-sight propagation in free space, implementing the same-frequency suppression interference on the receiver. This interference method applies a stronger signal at the same frequency, thereby drowning the original communication signal, causing the receiver to be unable to decode and receive the expected information normally; on a circle with the interference source as the center and the farthest interference distance as the radius, the receiver on the outer circle of the circle is the undisturbed node, the receiver on the inner circle of the circle is the interfered node, and the receiver falling on the circle is the edge node. The strength of the interference signal sent by the interference source to the edge node is threshold, and this interference signal strength threshold is the threshold;

[0089] S22, define that the mobile receiver receives the interference signal for the first time at time s during the movement process, that is, the interference signal strength received at this time is threshold, and is no longer interfered at time e+1. Based on the interference model, the receiver is an edge node of the interference model at time s and time e, and the received interference signal strength is approximately equal to threshold, that is, it satisfies the following formula (10):

[0090] P rs ,P re ∈[threshold-0.5Δ,threshold+0.5Δ] (10);

[0091] In formula (10), P rs is the interference signal strength received by the receiver at time s, P re is the interference signal strength received by the receiver at time e, and Δ is the error value;

[0092] The calculation formula for the interference signal strength received by the receiver is shown in the following formula (11):

[0093]

[0094] In formula (11), P t is the interference signal strength emitted by the interference source, G t is the gain of the interference source transmitting antenna, G rs is the receiving antenna gain of the receiver at time s, G re is the receiving antenna gain of the receiver at time e, G rs and G re Calculated by formula (8), λ is the wavelength of the interference signal, d is the distance between the receiver and the interference source, α is the environmental parameter, L is the loss factor of the receiver, L≥1;

[0095] S23. Solve the location (x, y, 0) of the interference source in the geographical area with longitude range [x0, x1] and latitude range [y0, y1], and define the location of the i-th grid point in the geographical area as (x i ,y i ,0),x i ∈[x0,x0+Δx,…,x1],y i ∈[y0,y0+Δy,…,y1], Δx and Δy represent the division interval values ​​of longitude and latitude when the geographical area is gridded;

[0096] Assume x = x i , y=y i , and then solve P according to formula (11) rs or P re , when the obtained P rs or P re If equation (10) is not satisfied, then the position of the i-th grid point is not the position of the interference source. rs or P re If equation (10) is satisfied, the position of the i-th grid point is taken as the assumed position of the interference source;

[0097] By the above calculation, the grid points that meet the assumed position of the interference source are found, thereby obtaining a set of candidate grid points as the predicted position of the interference source;

[0098] S24, the setting value of the allowed error value Δ and the threshold value threshold will directly affect the judgment result; if the Δ value is set too large, the judgment result will deviate from the characteristics of the edge node in the actual interference model, affecting the accuracy of the judgment; on the contrary, if the Δ value is set too small, due to the error in the signal strength calculation itself and the influence of external noise, the amount of data that meets the judgment conditions may be greatly reduced, thereby affecting the efficiency and accuracy of positioning or tracking, so Δ is defined to be between 1-2dBm;

[0099] The specific setting method of the threshold threshold and the error value Δ is as follows: first fix Δ and traverse threshold: for each set threshold value, determine whether all receivers meet the condition according to formula (10). If so, set the flag value corresponding to the receiver to 1, otherwise to 0. Finally, record the number of receivers res with a flag value of 1, and determine the threshold value corresponding to the maximum res as the optimal threshold; then fix the threshold value and traverse all set Δ. For each Δ value, check whether all receivers meet formula (10). If so, set the flag value corresponding to the receiver to 1. Finally, record the number of receivers res with a flag value of 1, and determine the Δ value corresponding to the maximum res as the optimal error value.

[0100] S25. When the i-th grid point is set as the interference source position, the result set of its flag value is {flag i1 ,flag i2 ,…,flag iN}, N is the total number of receivers. In the result set, the number of receivers with flag value equal to 1 is: Δ i and threshold i Respectively represent the optimal error value and optimal threshold corresponding to the i-th grid point, res i The larger it is, the greater the possibility that the i-th grid point is the location of the interference source;

[0101] For all grid point positions, the feature set of all grid points is calculated, as shown in the following formula (12):

[0102] {(res i ,Δ i ,threshold i )},1≤i≤M×M (12);

[0103] In formula (12), M×M is the total number of grid points;

[0104] The probability value is then used to quantify the possibility that the i-th grid point is the location of the interference source. For the location of the i-th grid point, the probability value is used It indicates the possibility that the location is the interference source location. The grid point corresponding to the maximum P(i) value is the location of the interference source.

[0105] The interference source location estimation system specifically includes a data acquisition and analysis system, a data communication transmission system and a UI interface. First, the user accesses the UI interface and checks in the default start page whether the interference source location estimation system has been connected to the data communication transmission system for data acquisition and analysis; when the connection has been established, the user selects the interference source location estimation function on the UI interface. In this function page, the user sets the time and the geographical area of ​​interest for screening, and then the data acquisition and analysis system automatically collects the navigation data interfered by the BDS. After completing the data screening operation, the user clicks the calculation button in the function page, and the data acquisition and analysis system automatically performs the estimation calculation of the BDS interference source, thereby obtaining the estimated interference source positioning heat map, which is then transmitted to the UI interface through the data communication transmission system. The interference source positioning heat map will be displayed on the high-precision map of the UI interface.

[0106] The interference source location estimation system is implemented based on Python programming. The client uses the Flask framework to develop Web applications, and uses USRP and GNURadio for data acquisition. The system development environment is Ubuntu 20.04.2LTS and Python 3.8. The client is mainly supported by two processes, data acquisition and analysis and Web, and the server is mainly supported by the background process of the BDS interference source location estimation algorithm.

[0107] User layer: The user layer implements the development of the Web front-end interface and back-end services based on the Python Flask framework. The front-end page uses JavaScript for UI design and event programming, and uses Cesium to integrate high-precision maps into the front-end interface. The collected data will be displayed on the high-precision map in real time according to the longitude and latitude, and Python is used for data processing, providing the function of filtering according to parameters such as time and geographic area; for the receiver data identified as having BDS interference, the front-end page sets a positioning calculation trigger button, and the user can trigger the positioning calculation logic by clicking the button.

[0108] Functional layer: Use the universal software radio platform USRP and GNURadio to complete data acquisition. By introducing the Python function library of GNURadio, the automation and modularization of data acquisition and analysis are realized, and the data acquisition and analysis process is encapsulated in a modular program; use USRP to perform wireless signal reception, filtering, AD conversion and mixing operations to convert the RF signal into a digital baseband signal; then, demodulate the digital baseband signal, and perform noise floor estimation, frame header detection, PPM bit judgment and CRC check in sequence; when estimating the noise floor, use the sliding window averaging method, set the sliding window to three leading sequence lengths to obtain the estimated noise floor; set the fixed pulse detection threshold to 7dB, so as to obtain the high-level detection threshold value of the leading sequence pulse, and use this threshold value to detect the leading frame header pulse;

[0109] The BDS interference source location estimation method based on signal strength is the core function of the system. Python is used to encapsulate the method as a function. The input parameter of the function is the collected receiver data set interfered by BDS, and the return value of the function is the positioning heat map. Each point in the interference source positioning heat map corresponds to an actual longitude and latitude, and the heat value indicates the probability that the longitude and latitude point is predicted to be the interference source location.

[0110] The data communication transmission function of the functional layer is implemented through message queues. Each message in the message queue contains the interfered receiver data set collected and transmitted by the client. These data are serialized and transmitted through the message queue for network communication. Every time the server receives a message, it obtains the receiver data set transmitted by the client through a deserialization operation, and sends the calculation results to another message queue for transmitting the positioning results after the calculation is completed. The client listens and receives the corresponding calculation results.

[0111] Data layer: To improve data access performance, the memory database Redis is used as data cache, and the collected data is cached in units of days. Earlier historical data is persistently stored using the relational database MySQL. To improve the query performance of the database, an index is created for the date column.

[0112] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for estimating the location of an interference source, characterized in that: The specific steps include: (1) Confirm the direction of the antenna on the receiver, define the relative position of the ground interference element and the receiver, and obtain the receiving antenna gain in the direction of the receiver BDS interference signal based on the Haversin formula and coordinate transformation; (2) The geographical area is divided into grids and the interference source is assumed to be located at one of the grid points in the geographical area. The strength of the received interference signal is estimated based on the collected data and the judgment criteria are used to determine whether the assumption is valid, thereby determining whether the interference source is located at a certain grid point in the geographical area.

2. The method for estimating the location of an interference source according to claim 1, characterized in that: The specific steps of confirming the direction of the antenna on the receiver, defining the relative position of the ground interference element and the receiver, and obtaining the receiving antenna gain in the direction of the receiver BDS interference signal according to the Haversin formula and coordinate transformation are as follows: S11. Collect the receiver location data and define the coordinates of the ground interference source as (lat Jam ,lon Jam ,0), the coordinates of the receiver are (lat p ,lon p ,hei p ); Based on the Haversine formula, that is, the following formula (1): Obtain the interference source ground point (lat Jam ,lon Jam ,0) to the receiver ground point (lat p ,lon p ,0), as shown in the following formula (2): d0=Rhsin -1 (hsin(φ2-φ1))+cosφ1cosφ2hsin(λ2-λ1) (2); In formula (2), R is the radius of the earth, φ2 is the latitude of the interference source, φ1 is the latitude of the receiver, λ2 is the longitude of the interference source, and λ1 is the longitude of the receiver; S12. Defined in the three-dimensional coordinate system, the angle θ between the projection of the receiver antenna pointing to the ground and the positive direction of the z-axis is calculated by the following formula (3): The moving direction of the receiver is defined as heading, the angle between the projection of the receiver-antenna system on the ground and the true north direction is φ, and the angle between the projection of the receiver antenna on the ground and the true north direction is φ0; The angle φ0 is calculated by the following formula (4): In formula (5), φ2 is the latitude of the interference source, φ1 is the latitude of the receiver, and Δλ represents the longitude difference between the receiver and the interference source coordinate point, that is, Δλ = |λ2-λ1|; The angle φ is calculated by the following formula (5): φ=heading-φ0 (5); When the receiver has complex azimuth changes, the azimuth is φ, the yaw angle is heading, then the direction vector corresponding to φ0 is The position in the receiver coordinate system is in Satisfies the following formula (6): Formula (6) is expanded to obtain the matrix equation shown in formula (7): The ground coordinate system is transformed into the receiver coordinate system by performing three rotation transformations according to formula (7); In formula (7), ψ is the X coordinate system of the receiver b Axis in ground coordinate system O e X e Y e Projection in the plane and X e The angle between the two axes; σ is the X b Axis and ground coordinate system O e X e Y e The angle between the planes; γ is the Y coordinate system of the receiver b Axis and ground coordinate system O e X e Y e The angle between the planes; Then according to the above formula (7), the direction vector After changing to the receiver coordinate system, (σ, ψ) is obtained; then the receiving antenna gain gain(σ, ψ) in the corresponding direction is obtained according to the following formula (8): In formula (8), σ c , σ f , ψ c , ψ f Satisfies the following formula (9): In formula (9), ceil() means rounding up, and floor() means rounding down.

3. The method for estimating the location of an interference source according to claim 2, characterized in that: The aforementioned grid-segmentation processing of the geographical area is performed, assuming that the interference source is located at one of the grid points in the geographical area, and then estimating the strength of the received interference signal based on the collected data, and using the judgment criteria to determine whether the assumption is established, thereby determining that the interference source is located at a certain grid point in the geographical area. The specific steps are: S21, the edge node falls on a circle with the interference source as the center and the farthest interference distance as the radius, and the interference signal strength sent by the interference source to the edge node is threshold, then the interference signal strength threshold is the threshold; S22, define that the mobile receiver receives the interference signal for the first time at time s during the movement process, that is, the interference signal strength received at this time is threshold, and is no longer interfered at time e+1. Based on the interference model, the receiver is an edge node of the interference model at time s and time e, and the received interference signal strength is approximately equal to threshold, that is, it satisfies the following formula (10): P rs ,P re ∈[threshold-0.5Δ,threshold+0.5Δ] (10); In formula (10), P rs is the interference signal strength received by the receiver at time s, P re is the interference signal strength received by the receiver at time e, and Δ is the error value; The calculation formula for the interference signal strength received by the receiver is shown in the following formula (11): In formula (11), P t is the interference signal strength emitted by the interference source, G t is the gain of the interference source transmitting antenna, G rs is the receiving antenna gain of the receiver at time s, G re is the receiving antenna gain of the receiver at time e, G rs and G re Calculated by formula (8), λ is the wavelength of the interference signal, d is the distance between the receiver and the interference source, α is the environmental parameter, L is the loss factor of the receiver, L≥1; S23. Solve the location (x, y, 0) of the interference source in the geographical area with longitude range [x0, x1] and latitude range [y0, y1], and define the location of the i-th grid point in the geographical area as (x i ,y i ,0),x i ∈[x0,x0+Δx,…,x1],y i ∈[y0,y0+Δy,…,y1], Δx and Δy represent the division interval values ​​of longitude and latitude when the geographical area is gridded; Assume x = x i , y=y i , and then solve P according to formula (11) rs or P re , when the obtained P rs or P re If equation (10) is not satisfied, then the position of the i-th grid point is not the location of the interference source. rs or P re If equation (10) is satisfied, the position of the i-th grid point is taken as the assumed position of the interference source.

4. The method for estimating the location of an interference source according to claim 3, characterized in that: The method for setting the threshold value threshold and the error value Δ is as follows: first, fix Δ and traverse threshold: for each set threshold value, determine whether all receivers meet the condition according to formula (10). If so, set the flag value corresponding to the receiver to 1, otherwise to 0. Finally, record the number of receivers res with a flag value of 1, and determine the threshold value corresponding to the maximum res as the optimal threshold; then fix the threshold value and traverse all set Δ. For each Δ value, check whether all receivers meet formula (10). If so, set the flag value corresponding to the receiver to 1. Finally, record the number of receivers res with a flag value of 1, and determine the Δ value corresponding to the maximum res as the optimal error value.

5. The method for estimating the location of an interference source according to claim 4, characterized in that: The i-th grid point is the interference source location, and the result set of its flag value is {flag i1 ,flag i2 ,…,flag iN }, N is the total number of receivers. In the result set, the number of receivers with flag value equal to 1 is: Δ i and threshold i They represent the optimal error value and optimal threshold corresponding to the i-th grid point, res i The larger it is, the more likely it is that the i-th grid point is the location of the interference source; For all grid point positions, the feature set of all grid points is calculated, as shown in the following formula (12): {(res i ,Δ i ,threshold i )},1≤i≤M×M (12); In formula (12), M×M is the total number of grid points; The probability value is then used to quantify the possibility that the i-th grid point is the location of the interference source. For the location of the i-th grid point, the probability value is used It indicates the possibility that the location is the interference source location. The grid point corresponding to the maximum P(i) value is the location of the interference source.

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