A method for detecting anomaly in observation data of BeiDou-3 high-dynamic receiver

Abstract

The invention relates to the field of satellite navigation technology, and in particular to a method for detecting anomaly of BeiDou-3 high-dynamic receiver observation data. The method comprises the following steps: S1: reading a priori real-time information provided by an inertial navigation system; S2: simultaneously reading real-time data of a satellite navigation receiver; S3: performing a priori residual test, and eliminating satellites with larger residuals by using a mathematical statistical method; and S4: performing iterative positioning and solving by using satellite information that has passed the a priori residual test, and calculating the residual of each satellite in real time by using the solved receiver position and speed information. The invention proposes a set of specific processing steps for detecting anomaly of BeiDou-3 high-dynamic receiver observation data by using inertial navigation auxiliary information, can effectively detect abnormal observation data in a high-dynamic environment, reduce the probability of missed alarms and false alarms in abnormal data detection, and prevent abnormal data from participating in positioning and solving to bias the result, thereby significantly improving the success rate of positioning and solving and positioning accuracy.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation technology, and in particular to a method for detecting anomaly in observation data of a BeiDou-3 high-dynamic receiver. Background Art

[0002] With the development of modern science and technology in my country, especially the development of military science and technology, the application of Beidou satellite navigation has become more and more extensive, especially in precision-guided bombs.

[0003] However, due to the highly dynamic operating environment of the bomb, satellite signal capture and tracking anomalies often occur. If these satellites with capture or tracking anomalies cannot be detected quickly and timely and are put into the positioning solution process, it will easily lead to positioning solution failure. Therefore, it is particularly important to detect these abnormal satellites in a timely and rapid manner.

[0004] Current methods for removing anomalous satellites from positioning solutions typically use a posteriori residual testing. However, this presents a problem: by including anomalously tracked or captured satellites in the navigation and positioning solution, the positioning result can be biased. Consequently, this autonomous integrity monitoring method cannot effectively and timely remove these anomalous satellites, resulting in non-positioning or excessive positioning deviations. Proper navigation and positioning solutions require the timely removal of anomalous satellites. This a posteriori residual testing approach can easily misreport normal measurements as errors and faults when the geometry of the satellite image is poor or when a large number of satellites with large errors are present, leading to false alarms and missed alarms. Furthermore, the difficulty in determining an appropriate rejection threshold also makes false alarms and missed alarms more likely. Navigation receivers in highly dynamic environments are prone to generating anomalous measurements due to high dynamic stress. Therefore, timely and effective detection of these anomalous measurements is crucial in these highly dynamic environments.

[0005] Aiming at this highly dynamic and harsh application environment, the present invention proposes a method for detecting anomalies in observation data using inertial navigation auxiliary data. Summary of the Invention

[0006] In order to overcome the problem that the traditional method adopts the a posteriori residual test method, abnormal satellites participate in the solution and pull the positioning results off, making it difficult to effectively remove abnormal satellites in a timely manner, and false alarms and missed alarms are prone to occur when the satellite image geometry is poor or there are many satellites with large errors. At the same time, the appropriate rejection threshold is difficult to determine, and abnormal observation values ​​cannot be detected in a timely and effective manner in a high dynamic environment.

[0007] The technical solution of the present invention is: a method for detecting abnormality of BeiDou-3 high-dynamic receiver observation data, which comprises the following steps: S1: reading a priori real-time information provided by an inertial navigation system; S2: simultaneously reading real-time data of a satellite navigation receiver; S3: performing a priori residual test, and eliminating satellites with large residuals using a mathematical statistical method; S4: performing iterative positioning solution using satellite information that has passed the a priori residual test, and calculating the residual of each satellite in real time using the calculated receiver position and velocity information; S5: judging whether the residual exceeds a threshold, eliminating satellites with excessive residuals, and re-performing positioning solution until all satellite residuals meet the requirements or the number of satellites is insufficient, and marking satellites with excessive residuals; S6: after the solution is completed, calculating the residuals of all satellites using the calculated receiver position, velocity and time information, and if the satellite that originally had a large residual now has a small residual, removing the mark of the original excessive residual; and S7: determining whether there is next epoch data to be processed, and if there is data, repeating the processing of steps S1 to S6, and if there is no data, the processing ends.

[0008] Preferably, the prior real-time information in step S1 includes the approximate position and speed of the high-dynamic carrier; a connection is established with the inertial navigation system through a dedicated interface, and the approximate position information of the high-dynamic carrier is read at a frequency of not less than 10 Hz, including the three-dimensional coordinates in the protocol earth coordinate system ( , , ), and at the same time obtain the velocity information of the carrier, that is, the three-dimensional velocity components ( , , After reading, the data is preliminarily filtered using a simple sliding average filter with a window size of 3 to remove burst noise in the data and improve data stability.

[0009] As a preference, in step S2, real-time data is obtained from the satellite navigation receiver baseband measurement module, including: accurate timestamp , accurate to nanosecond level; observation data, mainly pseudo-range , pseudorange rate and carrier phase ; Ephemeris information, including satellite orbit parameters and clock parameters, is used for subsequent satellite position and status calculations; the data acquisition frequency is consistent with the receiver sampling frequency, 1Hz-10Hz. After acquisition, the data is stored in a cache queue in chronological order for subsequent processing.

[0010] As a preferred method, the detailed steps of S3 are as follows: S31: Calculate the satellite's prior position and velocity, and calculate the position of each satellite at the current moment based on the ephemeris information, using the Kepler orbit model and combining the satellite's orbital elements, such as the semi-major axis, eccentricity, and orbital inclination. The three-dimensional position of , , ) and three-dimensional velocity ( , , ), in the calculation process, the influence of factors such as the earth's rotation and the relativistic effect on the satellite orbit is considered to improve the calculation accuracy; S32: calculate the prior pseudo-range, according to the approximate position of the carrier ( , , ) and satellite positions ( , , ), calculate the geometric distance d; , combined with the satellite and receiver clock bias , calculate the prior pseudorange ; ,in, is the speed of light; S33: calculate the prior residual, calculate the pseudorange prior residual of each satellite ; At the same time, according to the speed information of satellite and carrier, the pseudo-range first test residual is calculated. ; , S34: Statistical processing and outlier elimination, statistical analysis of the prior residuals of all satellites, using Principle, calculate the mean of the residuals and standard deviation ; If the pseudorange of a satellite or the pseudorange first check residual meets , then the satellite’s observation data is judged to be abnormal and it is removed from the data set.

[0011] As a preference, the detailed steps of iterative positioning solution and residual calculation in S4 are as follows: S41: Least squares positioning solution, using satellite information that has passed the prior residual test to establish a positioning equation. Taking pseudorange positioning as an example, the positioning equation is:

[0012] = + + ,in, For the Pseudorange measurements of satellites, For the The position of the satellites, is the receiver position to be solved, is the clock deviation between the receiver and the satellite, To measure noise; solve the above positioning equations by the least squares method to obtain the position of the receiver and speed ;S42: Real-time residual calculation, recalculate the pseudo-range residual of each satellite based on the calculated receiver position and velocity information and pseudorange rate residuals , the calculation method is the same as step S33.

[0013] As a preference, in step S5, the pseudorange residual threshold is set The threshold value is determined according to the actual application scenario and receiver performance. The pseudorange residual threshold is set to 1-3 meters, and the pseudorange rate residual threshold is set to 0.1-0.3 meters / second. If the pseudorange residual of a satellite is > or pseudorange rate residual > , then the satellite is judged to be abnormal, and it is removed from the positioning solution data, and a residual error flag is set for the satellite; after removing the abnormal satellite, the positioning solution is re-performed, and step S4 is repeated until the residual errors of all satellites meet the requirements, that is, and ≤ , or the number of remaining satellites is insufficient for positioning solution, the number of satellites must be greater than or equal to 4.

[0014] As a preference, in step S6, if a satellite that was originally judged to have a large residual and set a flag, now has a residual that meets the requirement, that is, and ≤ , then remove the excessive residual flag of the satellite and include it back in the category of available satellites.

[0015] Preferably, in step S7, the final positioning result and satellite status information are output after the processing is completed.

[0016] The beneficial effects of the present invention are as follows: By utilizing inertial navigation auxiliary information, the present invention proposes a set of specific processing steps for detecting abnormal observation data of BeiDou-3 high-dynamic receivers, which can effectively detect abnormal observation data in a high-dynamic environment, reduce the probability of missed alarms and false alarms in abnormal data detection, and avoid abnormal data from participating in positioning and solving biased results, thereby significantly improving the success rate and positioning accuracy of positioning and solving, and meeting the stringent requirements of high-dynamic application scenarios for navigation and positioning accuracy and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 What is shown is a flow chart of the method for detecting anomaly in the BeiDou-3 high-dynamic receiver observation data of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and examples.

[0019] See also Figure 1The present invention provides an embodiment: a method for detecting anomaly in observation data of a BeiDou-3 high-dynamic receiver, and the steps are as follows.

[0020] S1: Read the prior real-time information provided by the inertial navigation system; the prior real-time information includes the approximate position and speed of the high-dynamic carrier; establish a connection with the inertial navigation system through a dedicated interface, and read the approximate position information of the high-dynamic carrier at a frequency of not less than 10Hz, including the three-dimensional coordinates in the protocol earth coordinate system ( , , ), and at the same time obtain the velocity information of the carrier, that is, the three-dimensional velocity components ( , , After reading, the data is preliminarily filtered using a simple sliding average filter with a window size of 3 to remove burst noise in the data and improve data stability.

[0021] S2: Simultaneously read the real-time data of the satellite navigation receiver; obtain real-time data from the satellite navigation receiver baseband measurement module, including: accurate timestamp , accurate to nanosecond level; observation data, mainly pseudo-range , pseudorange rate and carrier phase ; Ephemeris information, including satellite orbit parameters and clock parameters, is used for subsequent satellite position and status calculations; the data acquisition frequency is consistent with the receiver sampling frequency, 1Hz-10Hz. After acquisition, the data is stored in a cache queue in chronological order for subsequent processing.

[0022] S3: Prior residual test, using mathematical statistics to eliminate satellites with large residuals; S31: Calculate the satellite's prior position and velocity, based on the ephemeris information, using the Kepler orbit model, combined with the satellite's orbital elements, such as the semi-major axis, eccentricity, and orbital inclination, to calculate the current position and velocity of each satellite. The three-dimensional position of and three-dimensional velocity In the calculation process, the influence of factors such as the earth's rotation and the relativistic effect on the satellite orbit is considered to improve the calculation accuracy; S32: Calculate the prior pseudo-range, based on the approximate position of the carrier and satellite positions , calculate the geometric distance d; , combined with the satellite and receiver clock bias , calculate the prior pseudorange ; ,in, is the speed of light; S33: calculate the prior residual, calculate the pseudorange prior residual of each satellite ; At the same time, according to the speed information of the satellite and the carrier, the pseudo-range first test residual is calculated ; , S34: Statistical processing and outlier elimination, statistical analysis of the prior residuals of all satellites, using Principle, calculate the mean of the residuals and standard deviation ; If the pseudorange of a satellite or the pseudorange first check residual meets , then the satellite’s observation data is judged to be abnormal and it is removed from the data set.

[0023] S4: Use the satellite information that has passed the prior residual test to perform iterative positioning solution, and use the calculated receiver position and velocity information to calculate the residual of each satellite in real time; the detailed steps of iterative positioning solution and residual calculation are as follows: S41: Least squares positioning solution, use the satellite information that has passed the prior residual test to establish the positioning equation.

[0024] Taking pseudorange positioning as an example, the positioning equation is: ,in, For the Pseudorange measurements of satellites, For the The position of the satellites, is the receiver position to be solved, is the clock deviation between the receiver and the satellite, To measure noise; solve the above positioning equations by the least squares method to obtain the position of the receiver and speed ;42: Real-time residual calculation, recalculate the pseudo-range residual of each satellite based on the calculated receiver position and velocity information and pseudorange rate residuals , the calculation method is the same as step S33.

[0025] S5: Determine whether the residual exceeds the threshold, and remove the satellites with excessive residuals, and re-calculate the positioning solution until all satellite residuals meet the requirements or the number of satellites is insufficient, and mark the satellites with excessive residuals; set the pseudorange residual threshold The threshold value is determined according to the actual application scenario and receiver performance. The pseudorange residual threshold is set to 1-3 meters, and the pseudorange rate residual threshold is set to 0.1-0.3 meters / second. If the pseudorange residual of a satellite is > or pseudorange rate residual > , then the satellite is judged to be abnormal, and it is removed from the positioning solution data, and a residual error flag is set for the satellite; after removing the abnormal satellite, the positioning solution is re-performed, and step S4 is repeated until the residual errors of all satellites meet the requirements, that is, ≤ and ≤ , or the number of remaining satellites is insufficient for positioning solution, the number of satellites must be greater than or equal to 4.

[0026] S6: After the solution is completed, the residuals of all satellites are calculated using the calculated position, velocity and time information of the receiver. If a satellite that was originally judged to have too large residuals and set a flag now meets the requirements, that is, ≤ and ≤ , then remove the excessive residual flag of the satellite and include it back in the category of available satellites.

[0027] S7: Check whether there is next epoch data to be processed. If there is data, repeat the processing of steps S1-S6. If there is no data, the processing ends and the final positioning result and satellite status information are output.

[0028] Experimental example: The experimental hardware equipment is as follows: BeiDou-3 high-dynamic receiver: simulates signal reception in a high-dynamic operating environment; high-precision inertial navigation system: provides carrier prior position and velocity information, with an accuracy of position error ≤ 0.1 meter and velocity error ≤ 0.01 meter / second; signal simulator: can simulate satellite signals in high-dynamic scenarios, including different dynamic stresses, satellite geometric configurations, etc.; software platform: experimental data processing software: used to implement the algorithm of the method of the present invention and the traditional a posteriori residual test method, as well as the calculation, analysis and storage of data; simulation analysis software: performs visual analysis of the experimental data and compares the detection results and positioning effects of the two methods.

[0029] Experimental data acquisition; 1) Use a signal simulator to generate multiple sets of satellite signal data under high-dynamic scenarios. The simulated scenarios include: high-speed linear motion: speed 200 m / s, acceleration 5 m / s²; high-speed turning motion: speed 150 m / s, turning angular velocity 0.5 rad / s; accelerated dive motion: initial speed 100 m / s, acceleration 8 m / s², dive angle 30°; 2) Each set of scenario data contains normal satellite signals and artificially added abnormal satellite signals, with the abnormal ratio set to 10%-30%. Observation data is collected through the BeiDou-3 high-dynamic receiver, and the real-time position and velocity information of the carrier is collected using a high-precision inertial navigation system.

[0030] Experimental grouping: The collected data are divided into two groups. As Experimental Example 1, the anomaly detection method based on inertial navigation assistance proposed in this invention is used for processing. The other group, as Experimental Example 2, uses the traditional posterior residual test method for anomaly detection and positioning solution.

[0031] The experimental steps of Experimental Example 2 are as follows: Directly perform positioning solution on the collected observation data; Calculate the residual based on the positioning solution result, use fixed thresholds, pseudorange residual threshold of 2 meters, and pseudorange rate residual threshold of 0.2 meters / second to identify and eliminate abnormal satellites. Repeat the positioning solution until the convergence condition is met or the number of satellites is insufficient; Data recording and analysis: Record the following indicators of the two methods in each set of data processing: Number of missed alarms: the number of abnormal satellites that are not detected. Number of false alarms: the number of normal satellites that are mistakenly judged as abnormal. Positioning solution success rate: the proportion of the number of successful positioning solutions to the total number of times. Positioning accuracy: the average error between the solved position and the true position (unit: meter). The data results are shown in the following table:

[0032]

[0033] It can be seen from the experimental data that in a high-dynamic environment, the BeiDou-3 high-dynamic receiver observation data anomaly detection method based on inertial navigation assistance proposed in the present invention is superior to the traditional a posteriori residual test method in terms of the number of missed alarms, the number of false alarms, the positioning solution success rate and the positioning accuracy, which effectively verifies the effectiveness and superiority of the method of the present invention.

Claims

1. A method for detecting anomaly in BeiDou-3 high-dynamic receiver observation data, characterized in that: The steps are as follows: S1: read the a priori real-time information provided by the inertial navigation; S2: simultaneously read the real-time data of the satellite navigation receiver; S3: a priori residual test, and use mathematical statistics to eliminate satellites with large residuals; S4: use the satellite information that has passed the a priori residual test to perform iterative positioning solution, and use the solved receiver position and velocity information to calculate the residual of each satellite in real time; S5: determine whether the residual exceeds the threshold, and eliminate the satellites with too large residuals, and re-perform positioning solution until all satellite residuals meet the requirements or the number of satellites is insufficient, and mark the satellites with too large residuals; S6: after the solution is completed, use the solved receiver position, velocity and time information to calculate the residuals of all stars. If the satellite with a large residual originally has a smaller residual now, the mark of the original excessive residual is removed; S7: Check if there is next epoch data to be processed. If there is data, repeat the process of steps S1-S6. If there is no data, the process ends.

2. The method for detecting anomaly of BeiDou-3 high-dynamic receiver observation data according to claim 1, characterized in that: The prior real-time information in step S1 includes the approximate position and speed of the high-dynamic carrier; a connection is established with the inertial navigation system through a dedicated interface to read the approximate position information of the high-dynamic carrier at a frequency of not less than 10Hz, including the three-dimensional coordinates in the protocol earth coordinate system , and simultaneously obtain the velocity information of the carrier, that is, the three-dimensional velocity components After reading, the data is preliminarily filtered using a simple sliding average filter with a window size of 3 to remove burst noise in the data and improve data stability.

3. The method for detecting anomaly in BeiDou-3 high-dynamic receiver observation data according to claim 1, characterized in that: In step S2, real-time data is obtained from the satellite navigation receiver baseband measurement module, including: accurate timestamp , accurate to nanosecond level; observation data, mainly pseudo-range , pseudorange rate and carrier phase ; Ephemeris information, including satellite orbit parameters and clock parameters, is used for subsequent satellite position and status calculations; the data acquisition frequency is consistent with the receiver sampling frequency, 1Hz-10Hz. After acquisition, the data is stored in a cache queue in chronological order for subsequent processing.

4. The method for detecting anomaly in BeiDou-3 high-dynamic receiver observation data according to claim 3, characterized in that: The detailed steps of S3 are as follows: S31: Calculate the satellite's prior position and velocity: Based on the ephemeris information, use the Kepler orbit model and combine the satellite's orbital elements, such as the orbital semi-major axis, eccentricity, and orbital inclination to calculate the position and velocity of each satellite at the current moment. The three-dimensional position of , , ) and three-dimensional velocity ( , , ), in the calculation process, the influence of the earth's rotation and relativistic effects on the satellite orbit is considered to improve the calculation accuracy; S32: Calculate the prior pseudorange: according to the approximate position of the carrier ( , , ) and satellite positions ( , , ), calculate the geometric distance d; , combined with the satellite and receiver clock bias , calculate the prior pseudorange ; ,in, is the speed of light; S33: Calculate the prior residual: Calculate the prior residual of the pseudorange of each satellite ; = At the same time, according to the speed information of the satellite and the carrier, the pseudo-range first test residual is calculated ; in, is the prior value of the pseudorange change rate; S34: Statistical processing and anomaly elimination: Statistical analysis of the prior residuals of all satellites is performed using Principle, calculate the mean of the residuals and standard deviation ; If the pseudorange of a satellite or the pseudorange first check residual meets , then the satellite’s observation data is judged to be abnormal and it is removed from the data set.

5. The method for detecting anomaly in BeiDou-3 high-dynamic receiver observation data according to claim 4, characterized in that: The detailed steps of iterative positioning solution and residual calculation in S4 are as follows: S41: Least squares positioning solution: Use the satellite information that has passed the prior residual test to establish the positioning equation, where the positioning equation for pseudorange positioning is: ,in, For the Pseudorange measurements of satellites, ( , , ) is the The positions of satellites, ( , , ) is the receiver position to be solved, is the clock deviation between the receiver and the satellite, To measure the noise; solve the above equation by the least square method to obtain the position of the receiver ( , , ) and speed ( , , ); S42: Real-time residual calculation: Recalculate the pseudorange residual of each satellite based on the calculated receiver position and velocity information and pseudorange rate residuals , the calculation method is the same as step S33.

6. The method for detecting anomaly in BeiDou-3 high-dynamic receiver observation data according to claim 1, characterized in that: In step S5, set the pseudorange residual threshold The threshold value is determined according to the actual application scenario and receiver performance. The pseudorange residual threshold is set to 1-3 meters, and the pseudorange rate residual threshold is set to 0.1-0.3 meters / second. If the pseudorange residual of a satellite is > or pseudorange rate residual > , then the satellite is judged to be abnormal, and it is removed from the positioning solution data, and a residual error flag is set for the satellite; after removing the abnormal satellite, the positioning solution is re-performed, and step S4 is repeated until the residual errors of all satellites meet the requirements, that is, ≤ and ≤ , or the number of remaining satellites is insufficient for positioning solution, the number of satellites must be greater than or equal to 4.

7. The method for detecting anomaly in BeiDou-3 high-dynamic receiver observation data according to claim 6, characterized in that: In step S6, if a satellite that was originally judged to have a large residual and set a flag, now has a residual that meets the requirements, that is, and , then remove the excessive residual flag of the satellite and include it back in the category of available satellites.

8. The method for detecting anomaly of BeiDou-3 high-dynamic receiver observation data according to claim 1, characterized in that ; In step S7, the final positioning result and satellite status information are output after the processing is completed.

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