阅读说明：本技术 利用qar/ads-b数据基于到达功率差的稳健gnss干扰源定位方法 (Robust GNSS interference source positioning method based on arrival power difference by using QAR/ADS-B data ) 是由 王晓亮 王一鸣 吴仁彪 何炜琨 王文益 贾琼琼 胡铁乔 于 2021-08-23 设计创作，主要内容包括：利用QAR/ADS-B数据基于到达功率差的稳健GNSS干扰源定位方法,其中包括根据一定范围内大量受干扰航迹干扰开始和终止位置的三维坐标及机型信息,以及根据受干扰航迹干扰起始和终止位置到达功率差的特点构造代价函数,同时利用受干扰航迹干扰起始和终止位置的数据,并考虑不同飞机GNSS接收机性能可能存在差异的情况下对受干扰航迹分组构建优化代价函数,通过最小化代价函数推算干扰源所在位置。本发明提供的GNSS干扰源定位方法在不同航空器采用的机载GNSS接收设备性能存在差异性的情况下,仍能达到较高定位精度。(A robust GNSS interference source positioning method based on arrival power difference by using QAR/ADS-B data comprises the steps of constructing cost functions according to three-dimensional coordinates and model information of a large number of start and end positions interfered by interfered tracks in a certain range and according to the characteristics of arrival power difference of the start and end positions interfered by the interfered tracks, constructing optimized cost functions for interfered tracks in a grouping mode by using data of the start and end positions interfered by the interfered tracks and considering the fact that different aircraft GNSS receiver performances possibly have differences, and calculating the positions of interference sources through the minimized cost functions. The GNSS interference source positioning method provided by the invention can still achieve higher positioning accuracy under the condition that the performances of airborne GNSS receiving equipment adopted by different aircrafts have differences.)

1. The method for positioning the robust GNSS interference source based on the arrival power difference by using the QAR/ADS-B data is characterized in that: the method comprises the following steps of using interfered track data obtained by QAR data or ADS-B data, including three-dimensional coordinates and model information of an interfered track interference starting position and an interfered track interference ending position, utilizing a cost function related to an arrival power difference and designed as follows, and estimating the position of an interference source by solving a parameter value which enables the cost function to be minimum, wherein the method specifically comprises the following steps:

(1) grouping the interfered tracks, and setting the interference theoretical power P of the interference termination positions of all the interfered tracks in the ith group₂(i) Interference theoretical power P of initial position interfered by interfered track₁(i) Ratio P of₂(i)/P₁(i) The correction coefficients are the same and are all alpha (i) K, the theoretical power ratios in different groups are different, wherein alpha (i) is a correction coefficient of the theoretical power ratios of different groups of tracks, the 1 st group is a reference group, the theoretical power ratio is defined as K, and alpha (1) is 1;

(2) and constructing a cost function corresponding to the interfered track by utilizing the characteristics that the square of the theoretical distance ratio from the interference starting position and the interference ending position of the interfered track to the interference source in the same group is the same as the reciprocal of the theoretical power ratio of the interference starting position and the interference ending position. For disturbed start position at { x₁(i,j),y₁(i,j),z₁(i, j) }, interfered termination position is in { x }₂(i,j),y₂(i,j),z₂(i, j) } the ith group of the jth interfered track when the interference source is positioned at (x)₀,y₀,z₀) In the process, the cost function of the jth interfered track of the ith group is the square of the ratio of the distance from the interfered initial position to the interference source to the distance from the interfered termination position to the interference source, the theoretical power ratio alpha (i) K of the ith group of interfered tracks is subtracted, and then the square value is taken, namely the power ratio alpha (i) K of the jth interfered track of the ith group of interfered tracks is obtained

(3) The total cost function is the accumulated sum of all the interfered track cost functions;

(4) general assemblyThe cost function comprises (x)₀,y₀,z₀) K, α (i) a number of variables to be optimized.

2. The method of claim 1, wherein the QAR/ADS-B data based robust GNSS interference source positioning method based on arrival power difference comprises: and grouping the interfered tracks according to the difference of the airborne GNSS receivers. According to prior information of models of different types of onboard GNSS receivers, converting the corresponding relation between the flight path and the airplane type into the corresponding relation between the flight path and the onboard GNSS receiver, grouping the same flight path of the GNSS receivers into the same group, and grouping different flight paths of the GNSS receivers into different groups; when the prior information of the model of the GNSS receiver carried by different models cannot be obtained, the models are directly grouped according to the models, interfered tracks of the same model are classified into the same group, and interfered tracks of different models are classified into different groups.

3. The method of claim 1, wherein the QAR/ADS-B data based robust GNSS interference source positioning method based on arrival power difference comprises: when prior information of performance difference of GNSS receivers can be obtained, the simplified method for estimating the position of the interference source by solving the parameter value which minimizes the cost function is that alpha (i) is determined in advance by the prior information of different GNSS receivers, alpha (i) becomes a known quantity in the optimization operation of the cost function, and the variable (x) is related to₀,y₀,z₀) The optimization problem of K, α (i) is reduced to that for the variable (x)₀,y₀,z₀) And K.

4. A simplified method of estimating the location of an interfering source by solving the parameter values that minimize the cost function as claimed in claim 3, characterized by: when prior information of GNSS receiver performance difference can be obtained, a further simplified method for estimating the position of the interference source by solving a parameter value which minimizes the cost function is to determine K in advance through the prior information of the GNSS receiver, so that K in the optimization operation of the cost function becomes a known quantity, and the simplified related variable (x) is obtained₀,y₀,z₀) K ofThe optimization problem is further reduced to a variable (x)₀,y₀,z₀) To the optimization problem of (2).

5. The method of claim 1, wherein the QAR/ADS-B data based robust GNSS interference source positioning method based on arrival power difference comprises: in estimating the location of the interfering source by solving the parameter values that minimize the cost function, the height values z are computed using a terrain database₀Constrained to the surface to simplify the solution process.

Technical Field

The invention belongs to the field of positioning of Global Navigation Satellite System (GNSS) interference sources, and particularly relates to a GNSS interference source positioning method using interfered tracks in the field.

Background

The GNSS signal is a weak signal which is easy to interfere, and an interference source can cause the lock losing of an airborne GNSS receiver of a flight in the flight process, influence the integrity of a navigation system and threaten the running safety of civil aviation. How to locate the interference source in time becomes a practical problem which needs to be solved urgently.

In the existing ground interference investigation technology, the cost of a ground monitoring network laying mode is high; the manner of using a mobile interference detection device for large-scale troubleshooting is inefficient, time consuming and labor intensive. Data of a Quick Access Recorder (QAR) or a Broadcast Automatic Dependent Surveillance system (ADS-B) is analyzed, and a mode of positioning an interference source according to an interfered track is gradually a potential technical means due to low cost and good timeliness.

In the research Of obtaining interfered track data by ADS-B data abroad to position an interference source, European EUROCONROL researchers put forward a method for estimating the position Of the interference source by using a thermodynamic diagram to represent probability based on the assumption that the Power Difference Of Arrival (PDOA) is known and the same, but the principle Of calculating the thermodynamic diagram is unreasonable, the reliability Of the method depends on the accuracy Of prior information Of the Power Difference Of Arrival, the method does not consider the Difference Of GNSS receivers on different airplanes, and the Difference can greatly influence the estimation accuracy Of the position Of the interference source.

Disclosure of Invention

The invention provides a robust GNSS interference source positioning method based on arrival power difference by using QAR/ADS-B data to solve the problems in the background art.

In order to achieve the purpose, the invention provides the following technical scheme:

obtaining three-dimensional coordinates and model information of a large number of interfered track interference starting positions and interference ending positions in a certain range by QAR or ADS-B data, estimating interference source positions by utilizing cost functions related to arrival power difference and solving parameter values enabling the cost functions to be minimum, and specifically comprising the following steps:

(1) grouping the interfered tracks, wherein the interference theoretical power P of all interference termination positions (namely the recapture positions of the GNSS receiver) of the interfered tracks in the ith group₂(i) Interference theoretical power P with interfered track interference starting position (namely GNSS receiver out-of-lock position)₁(i) Ratio P of₂(i)/P₁(i) The theoretical power ratios are all the same and are alpha (i) K, the theoretical power ratios in different groups are different, wherein alpha (i) is a correction coefficient of the theoretical power ratios of different groups of tracks, the 1 st group is a reference group, the theoretical power ratio is defined as K, and alpha (1) is 1.

(2) And constructing a cost function corresponding to the interfered track by utilizing the characteristics that the square of the theoretical distance ratio from the interference starting position and the interference ending position of the interfered track to the interference source in the same group is the same as the reciprocal of the theoretical power ratio of the interference starting position and the interference ending position. For disturbed start position at { x₁(i,j),y₁(i,j),z₁(i, j) }, interfered termination position is in { x }₂(i,j),y₂(i,j),z₂(i, j) } the ith group of the jth interfered track when the interference source is positioned at (x)₀,y₀,z₀) In the process, the cost function of the jth interfered track of the ith group is the square of the ratio of the distance from the interfered initial position to the interference source to the distance from the interfered termination position to the interference source, after the theoretical power ratio alpha (i) K of the ith group of interfered tracks is subtracted, the square value is taken, namely the power ratio alpha (i) K of the jth interfered track of the ith group of interfered tracks is obtained

(3) For a co-contained I set of disturbed tracks, the I-th set contains J_iIn the case of a disturbed track, the total cost function is the cumulative sum of all the disturbed track cost functions. Namely, it is

(4) The total cost function contains (x)₀,y₀,z₀) K, α (i) a number of variables to be optimized.

Preferably, the interfered tracks are grouped according to the difference of the on-board GNSS receivers. According to prior information of models of different types of onboard GNSS receivers, converting the corresponding relation between the flight path and the airplane type into the corresponding relation between the flight path and the onboard GNSS receiver, grouping the same flight path of the GNSS receivers into the same group, and grouping different flight paths of the GNSS receivers into different groups; when the prior information of the model of the GNSS receiver carried by different models cannot be obtained, the models are directly grouped according to the models, interfered tracks of the same model are classified into the same group, and interfered tracks of different models are classified into different groups.

Preferably, in the process of estimating the interference source position by solving the parameter value for minimizing the cost function, when the prior information of the performance difference of the GNSS receiver can be obtained, the simplified method of the solving process is to determine α (i) in advance by the prior information of different GNSS receivers, so that α (i) becomes a known quantity in the optimization operation of the cost function, and the variable (x) is related to₀,y₀,z₀) The optimization problem of K, α (i) is reduced to that for the variable (x)₀,y₀,z₀) And K.

Preferably, in the process of estimating the interference source position by solving the parameter value for minimizing the cost function, when the prior information of the performance difference of the GNSS receiver can be obtained, the further simplification method of the solving process is to determine K in advance by the prior information of the GNSS receiver, so that the simplified variable (x) is related to₀,y₀,z₀) K to a further simplification with respect to the variable (x)₀,y₀,z₀) To the optimization problem of (2).

Preferably, the height value z is estimated using a terrain database in estimating the location of the interfering source by solving the parameter value that minimizes the cost function₀Constrained to the surface to simplify the solution process.

Compared with the prior art, the invention has the following advantages:

(1) when the ratio of the lock losing power to the recapture power of the airborne GNSS receiver cannot be known in advance, the method still can keep better positioning performance.

(2) The method simultaneously considers the difference of the airborne GNSS receiver, the model is closer to the real situation, and the algorithm interference source positioning still has better positioning performance and is more stable when the difference exists in the airplane airborne GNSS receiver corresponding to the analyzed interfered track.

The objects, features, and advantages of the present invention can be described in detail by the following drawings and examples.

Drawings

FIG. 1 is a processing flow diagram of a robust GNSS interference source positioning method based on arrival power difference using QAR/ADS-B data according to the present invention;

FIG. 2 is a schematic diagram of an interference source positioning model established by the present invention;

FIG. 3 is a schematic diagram of the positioning effect of simulation data according to the present invention;

FIG. 4 is a comparison of the interference source localization results obtained by the method of the present invention on a set of simulation data with other methods.

Detailed Description

The robust GNSS interference source positioning method based on the arrival power difference using QAR/ADS-B data according to the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1, the processing procedure of the method for locating the interference source includes:

and acquiring the longitude and latitude and the height of the interference starting position and the interference ending position of each interfered track in the attention area range by using the interfered track data obtained by the QAR data or the ADS-B data, converting the longitude and latitude and the height into three-dimensional coordinates under a rectangular coordinate system, and acquiring airplane model information corresponding to each interfered track.

And grouping the interfered tracks according to the difference of the airborne GNSS receivers corresponding to the interfered tracks. According to the information of the types of the GNSS receivers carried by different types of the aircraft, the corresponding relation between the flight path and the aircraft type is converted into the corresponding relation between the flight path and the airborne GNSS receiver, the same flight paths of the GNSS receivers are grouped into the same group, and the different flight paths of the GNSS receivers are grouped into different groups. When the prior information of the model of the GNSS receiver carried by different models cannot be obtained, the models are directly grouped according to the models, interfered tracks of the same model are classified into the same group, and interfered tracks of different models are classified into different groups.

Constructing an optimized cost function

And constructing a cost function corresponding to the interfered track by utilizing the characteristics that the square of the theoretical distance ratio from the interference starting position and the interference ending position of the interfered track to the interference source in the same group is the same as the reciprocal of the theoretical power ratio of the interference starting position and the interference ending position. After the tracks are grouped, the interfered tracks are divided into I groups, and the number of the interfered tracks contained in the I-th group is J_i(I ═ 1,2, …, I). Let the interference source be located at (x)₀,y₀,z₀) And for the ith group j of interfered tracks, the coordinates of the interference starting position are { x }₁(i,j),y₁(i,j),z₁(i, j) }, and the interference termination position coordinate is { x }₂(i,j),y₂(i,j),z₂(i, j) }. Interference theoretical power P of all interfered track interference termination positions (namely GNSS receiver recapture positions) in the ith group₂(i) Interference theoretical power P with interfered track interference starting position (namely GNSS receiver out-of-lock position)₁(i) Ratio P of₂(i)/P₁(i) The theoretical power ratios are all the same and are alpha (i) K, and the theoretical power ratios in different groups are different, wherein alpha (i) is a correction coefficient of the theoretical power ratios of different groups of tracks. Constructing a cost function to be optimized as

The cost function is a function of the sum of (x)₀,y₀,z₀) K, α (i) a function of a plurality of variables to be optimized.

Optimization problem construction and simplification

Solving for variables (x) when a priori information about GNSS receiver performance differences is unknown₀,y₀,z₀) K, α (i) an optimization problem that minimizes the cost function. I.e. by solving

The location of the possible interference sources is estimated. Where α ═ { α (1), α (2), …, α (I) }, and α (1) ═ 1. When the difference of the re-spread out-of-lock power ratios of different sets of GNSS receivers can be known by using the prior information, a is determined in advance as { α (1), α (2), …, α (I) } by using the prior information. The a priori information may be receiver parameters, historical data, or pre-experimental results. And optimizing after solving, wherein the optimization problem is simplified into the solving of the related variable (x)₀,y₀,z₀) And K. I.e. by solving

The location of the possible interference sources is estimated. When the GNSS receiver re-spread lock-losing power ratio can be obtained by using the prior information, K is further determined in advance by using the prior information, and the optimization problem is simplified to solve the related variable (x)₀,y₀,z₀) To the optimization problem of (2). I.e. by solving

The location of the possible interference sources is estimated.

Optimization problem solving

Searching extreme points of the cost function by using a grid method, and taking the (x) corresponding to the minimum value of the cost function₀,y₀,z₀) The method provides an estimate of the location of the source of the interferer. And gridding and dividing the search area, wherein the grid size delta r of the interference source position search can be set according to the positioning precision requirement. By utilizing a terrain database, the search area is limited to the surface to simplify the search in the elevation dimension.

The effects of the present invention can be further illustrated by the following simulation experiments.

Description of simulation data

The power ratio K of recapture to the unlocking threshold of the model 1 airborne GNSS receiver set as the reference is 0.5dB, and the interference source causes the model 1Radius r of the lost lock influence zone₁40km, the radius r of the out-of-lock influence area caused by the interference source to the model 2₂It was 28.32 km.

In order to compare the interference source position estimation performance of the method and the prior method under different conditions, the correction terms alpha (2) of the model 2 relative to the reference recapture and the unlocking threshold power ratio are respectively set to be 0dB and 0.5dB, and the relationship between the receiving power and the distance is determined according to the received powerRecapture radius for computer model 1 and model 2. The Monte Carlo experiments are carried out for 50 times under two conditions, and the position of the interference source in each experiment is randomly distributed within a range of 100m in a grid delta r by taking a preset interference source position as a center. After the position of the interference source is set, interfered tracks generated when 2 different airborne GNSS receivers are interfered are generated. The experimental tracks are randomly distributed along two main directions each time, and the condition that the civil aircraft flies along a fixed air route is simulated. The deviation of the actual distance from the interference starting and stopping position to the interference source position of the interfered track in each experiment and the theoretical distance is also randomly distributed. And adding Gaussian white noise with the mean value mu being 0m and the standard deviation sigma being 100m to the actual distance between the start-stop position of each interfered track and the interference source on the basis of the set distance. 50 simulation interfered tracks are generated, 25 interfered tracks are respectively contained in the model 1 and the model 2, and simulation data are schematically shown in FIG. 3 (only part of the tracks are shown in the figure).

Simulation experiment process

And selecting a probability thermodynamic diagram method based on the equal assumption of PDOA (product class of Automation) of EUROCONROL as the existing method to compare with the method. The method needs a predetermined ratio K of recapture to out-of-lock power of the airplane_XpThe probability calculation steps are as follows:

EUROCONRONTROL method calculates each grid point (x) by the grid method₀,y₀,z₀) Corresponding probability value F (x)₀,y₀,z₀) And look forLet F (x)₀,y₀,z₀) Point of maximum valueTo determine the location of the interferer source.

Simulation experiment results

Fig. 4 shows the positioning result of the interference source obtained by using the method of the present invention for one set of simulation data. Contour plots of the results and the probability distribution of the occurrence of the interference sources for one set of simulated data locations are shown. The set of simulation data resulted in a deviation of 19.30m between the estimated position of the interference source and the set position of the simulation.

Table 1 compares the Root Mean Square Error (RMSE) of the positioning results of the EUROCONROL method and the simulation experiment of the method of the present invention under different conditions. As can be seen from the table, the process of the invention maintains the RMSE less thanThe EUROCONROL method must be performed at a predetermined ratio of recapture to out-of-lock power (K) of the aircraft_XpK) and no difference between GNSS receivers (α (2) ═ 0dB) can be kept less thanThe accuracy of the estimation of.

In conclusion, the method can effectively position the position of the ground GNSS interference source, and when the airborne GNSS receivers corresponding to different tracks have differences, the positioning effect of the method is better than that of the existing method, the differences among the GNSS receivers are more stable, and the method is more beneficial to estimating the position of the ground GNSS interference source by analyzing flight big data in practical situations, thereby providing effective help for further troubleshooting and searching for the interference source.

Table 1.