阅读说明：本技术 一种紧组合导航转发式欺骗干扰检测方法 (Tightly-combined navigation forwarding type deception jamming detection method ) 是由 丁继成 任尚垠 赵琳 程建华 黄卫权 贾春 敖义路 王云龙 于 2021-09-08 设计创作，主要内容包括：本发明公开了一种紧组合导航转发式欺骗干扰检测方法,包括(1)采集GNSS接收机导航参数和SINS导航参数,对数据做预处理；(2)更新残差滑动窗口内数据,根据无欺骗干扰时存储的残差方差数据更新检测阈值；(3)根据前一历元各通道受欺骗情况进入相应检测程序；(4)按照动态时延欺骗信号分段检测的设计思想,依次进行动态时延过程检测和固定时延过程检测；(5)得到欺骗干扰检测结果并对检出欺骗通道所对应的卫星信号予以剔除；(6)更新历元信息,并重复执行(1)到(5),直至处理完所有历元。本发明实现了动态时延转发式欺骗干扰实时检测,能够检测码相位偏移速率不低于0.1chip/s的动态时延转发式欺骗干扰。(The invention discloses a close combination navigation forwarding type deception jamming detection method, which comprises the steps of (1) acquiring navigation parameters of a GNSS receiver and navigation parameters of an SINS (strapdown inertial navigation system), and preprocessing data; (2) updating data in a residual sliding window, and updating a detection threshold according to residual variance data stored when no deception interference exists; (3) entering a corresponding detection program according to the deception condition of each channel of the previous epoch; (4) according to the design idea of the dynamic time delay deception signal segmentation detection, the dynamic time delay process detection and the fixed time delay process detection are sequentially carried out; (5) obtaining a deception jamming detection result and eliminating satellite signals corresponding to the detected deception channels; (6) updating the epoch information, and repeatedly executing (1) to (5) until all epochs are processed. The invention realizes the real-time detection of the dynamic time delay forwarding type deception jamming, and can detect the dynamic time delay forwarding type deception jamming of which the code phase offset rate is not lower than 0.1 chip/s.)

1. A method for detecting the spoofing interference of a close-combination navigation forwarding type is characterized by comprising the following steps: the method comprises the following steps:

step 1: acquiring GNSS receiver navigation parameters and SINS navigation parameters, and preprocessing data;

step 2: updating data in a residual sliding window, and updating a detection threshold according to residual variance data stored when no deception interference exists;

and step 3: and judging each visible satellite: if the number num of the effective data in the residual sliding window is less than the capacity m of the sliding window, if so, the method does not have the detection condition, and the method does not enter the detection program for the moment, and if all the visible satellites do not have the detection condition, the method is ended; if the satellite channel is not established, entering a corresponding detection program according to a previous epoch deception flag Dec _ flag of the satellite channel and the cntr state of the isolation exit counter;

and 4, step 4: adopting dynamic time delay deception signal subsection detection, and sequentially carrying out dynamic time delay process detection and fixed time delay process detection;

and 5: obtaining a deception jamming detection result and rejecting satellite signals corresponding to the detected deception channel to obtain a deception jamming detection and combined navigation positioning result;

step 6: updating the epoch information, and repeatedly executing the steps 1 to 5 until all epochs are processed.

2. The method of claim 1, wherein the method comprises: step 2, updating the data in the residual error sliding window, wherein updating the detection threshold value according to the residual error data stored when no deception jamming exists is specifically as follows:

step 2.1: obtaining a pseudo range and a pseudo range rate residual error of a current epoch, specifically:

the expression of the GNSS/SINS tightly combined navigation system after the piecewise linearization processing is as follows: x is the number of_k＝Φ_k/k-1x_k-1+Γ_k-1w_k-1And z_k＝H_kx_k+v_kIn the formula, x_kIs a state vector; phi_k/k-1A one-step state transition matrix; gamma-shaped_k-1Is a system noise matrix; z is a radical of_kIs a vector of measured values; h_kIs a measurement matrix; w is a_k-1And v_kFor zero mean white noise vectors that are uncorrelated with each other, the closely combined system Kalman filter residual e_kIncluding pseudorange residuals pe_kAnd pseudorange rate residualsThe expression is as follows: e.g. of the type_k＝z_k-H_kx_k/k-1；

Step 2.2: updating a detection threshold value according to residual error data stored when no deception jamming exists, specifically: selecting window capacity according to the residual variance discrete degree and the calculated amount, and updating the detection threshold value in real time according to the set false alarm probability by using the pseudo-range and pseudo-range rate residual variance data which are stored when the detection threshold value is not subjected to deception interference;

step 2.3: updating data in the residual error sliding window, specifically: sliding window W ═ e with capacity m_k-m+1,e_k-m+2,…,e_k]Obtaining a sliding mean e using the residual of the first m-1 epoch_k-1And further obtaining a sliding variance, and updating data in the sliding window by each epoch through a shifting operation.

3. A method of detecting a tightly combined navigation-forwarded spoofed interference according to claim 1 or 2, characterized in that: if the satellite channel is not established, entering a corresponding detection program according to the previous epoch deception flag Dec _ flag and the state of the isolation exit counter cntr specifically comprises the following steps:

step 3.1: if the Dec _ flag is equal to 0 or 1, entering an isolation detection program, otherwise, continuously judging whether an isolation exit counter cntr is 0, and if the cntr is not 0, executing a step 3.2; if cntr is 0, go to step 3.3;

step 3.2: the satellite is in an isolation exit stage and executes an isolation exit detection program;

step 3.3: the satellite is not spoofed during the past filtering process and a conventional detection procedure is performed.

4. A method of detecting a tightly combined navigation-forwarded spoofed interference according to claim 1 or 2, characterized in that: step 4, adopting the dynamic time delay deception signal segmentation detection, and sequentially carrying out the dynamic time delay process detection and the fixed time delay process detection specifically comprises the following steps:

step 4.1: the dynamic time delay process detection specifically comprises the following steps: calculating a pseudo-range rate residual error variance, comparing the pseudo-range rate residual error variance with a pseudo-range rate residual error variance threshold, if the detected quantity is larger than the threshold, indicating that a dynamic time delay process exists and dynamic time delay forwarding type deception jamming exists, setting a deception flag Dec _ flag to be 1, assigning the deception flag Dec _ flag to a maximum count value set by a cntr of an isolation exit counter, and ending; if the detection quantity is smaller than the threshold value, the dynamic time delay process does not exist, and the step 4.2 is executed;

step 4.2: the fixed time delay process detection specifically comprises the following steps: calculating a pseudo-range residual error variance, comparing the pseudo-range residual error variance with a pseudo-range residual error variance threshold, if the detected quantity is larger than the threshold, indicating that a fixed time delay process exists and fixed time delay forwarding type deception interference exists, setting a deception flag Dec _ flag to be 1, assigning a maximum count value set by a cntr of an isolation exit counter, and ending; if the detection quantity is smaller than the threshold value, the forwarding type deception jamming does not exist, and a step 4.3 is executed;

step 4.3: when the deception jamming is not detected, corresponding operation is carried out on the isolation exit counter, and the method specifically comprises the following steps: executing a conventional detection program, resetting an isolation exit counter to zero, and setting a deception flag Dec _ flag to 0; executing an isolation exit detection program, and subtracting 1 from the isolation exit counter each time until the isolation exit counter returns to zero, wherein a deception flag Dec _ flag is set to 0; and executing an isolation detection program, giving the maximum value set by the isolation exit counter, and setting a deception flag Dec _ flag to be 0.

5. A method of detecting a tightly combined navigation-forwarded spoofed interference according to claim 1 or 2, characterized in that: the step 1 of collecting the GNSS receiver navigation parameters and the SINS navigation parameters, and the data preprocessing specifically comprises the following steps:

step 1.1: collecting GNSS receiver navigation parameters, comprising: time tag, satellite PRN number, carrier phase, pseudorange, doppler shift, signal strength, and ephemeris data;

step 1.2: acquiring SINS navigation parameters including specific force data, angular velocity data and a time tag updated each time by SINS;

step 1.3: preprocessing the acquired data, specifically: firstly, processing receiver observation data to obtain observation information, wherein the observation information comprises a time tag, a visible satellite PRN number, a pseudo range and a pseudo range rate; secondly, satellite position and speed calculation is carried out by extracting ephemeris parameters to obtain the three-dimensional position, speed, clock error and frequency drift of each visible satellite; and finally, carrying out time synchronization on the SINS navigation parameters and the GNSS receiver navigation parameters according to the same time tag.

6. A method of detecting a tightly combined navigation-forwarded spoofed interference according to claim 1 or 2, characterized in that: and 5, obtaining a deception jamming detection result and eliminating satellite signals corresponding to the detected deception channels, wherein the obtained deception jamming detection and combined navigation positioning results specifically comprise the following steps: isolating the deception interfered satellite channel, reconstructing a corresponding residual error matrix, a measurement noise covariance matrix and a gain matrix, combining navigation Kalman filtering end and state updating, and storing a current epoch deception detection result.

Technical Field

The invention relates to GNSS/SINS tight combination navigation forwarding type deception jamming detection, in particular to a tight combination navigation forwarding type deception jamming detection method based on residual dynamic time delay characteristics, and belongs to the technical field of satellite navigation deception detection.

Background

With the rapid development of global navigation satellite systems, the application of satellite navigation positioning technology is increasingly widespread. However, the receiver is prone to be induced to the wrong location by the effect of the repeater spoofing interference, which poses a serious challenge to the reliability of the receiver.

Currently, research on the detection of the repeater spoofing interference mainly focuses on both the independent receiver navigation without inertial navigation and the combined navigation with inertial navigation. When inertial navigation is not available, methods such as satellite signal power detection, correlation peak detection and pseudo-range difference detection are mainly adopted, but the methods lose the effect in a dynamic time delay forwarding type deception jamming scene that deception signal power is lower than that of a real signal and time delay is slowly increased. When inertial navigation exists, tightly combined residual errors chi are mainly adopted²Methods such as detection and tight combined pseudo-range difference detection cannot indicate a specific satellite affected by deception jamming and cannot perform deception suppression in a targeted manner; the latter uses the difference value of the receiver and the inertial navigation pseudo range or the tightly combined pseudo range residual error to carry out deception detection, can detect fixed time delay forwarding type deception jamming, but has no capability for dynamic time delay forwarding type deception jamming.

Disclosure of Invention

Aiming at the prior art, the technical problem to be solved by the invention is to provide a method for detecting the dynamic time delay forwarding type deception jamming by using the close-coupled navigation forwarding type deception jamming, which can realize the real-time detection of the dynamic time delay forwarding type deception jamming.

In order to solve the technical problem, the invention provides a method for detecting the close-combination navigation forwarding type deception jamming, which comprises the following steps:

step 1: acquiring GNSS receiver navigation parameters and SINS navigation parameters, and preprocessing data;

step 2: updating data in a residual sliding window, and updating a detection threshold according to residual variance data stored when no deception interference exists;

and step 3: and judging each visible satellite: if the number num of the effective data in the residual sliding window is less than the capacity m of the sliding window, if so, the method does not have the detection condition, and the method does not enter the detection program for the moment, and if all the visible satellites do not have the detection condition, the method is ended; if the satellite channel is not established, entering a corresponding detection program according to a previous epoch deception flag Dec _ flag of the satellite channel and the cntr state of the isolation exit counter;

and 4, step 4: adopting dynamic time delay deception signal subsection detection, and sequentially carrying out dynamic time delay process detection and fixed time delay process detection;

and 5: obtaining a deception jamming detection result and rejecting satellite signals corresponding to the detected deception channel to obtain a deception jamming detection and combined navigation positioning result;

step 6: updating the epoch information, and repeatedly executing the steps 1 to 5 until all epochs are processed.

The invention also includes:

1. updating data in the residual error sliding window in the step 2, and updating the detection threshold according to the residual error data stored when no deception jamming exists specifically comprises the following steps:

step 2.1: obtaining a pseudo range and a pseudo range rate residual error of a current epoch, specifically:

the expression of the GNSS/SINS tightly combined navigation system after the piecewise linearization processing is as follows: x is the number of_k＝Φ_k/k-1x_k-1+Γ_{k- 1}w_k-1And z_k＝H_kx_k+v_kIn the formula, x_kIs a state vector; phi_k/k-1A one-step state transition matrix; gamma-shaped_k-1Is a system noise matrix; z is a radical of_kIs a vector of measured values; h_kIs a measurement matrix; w is a_k-1And v_kFor zero mean white noise vectors that are uncorrelated with each other, the closely combined system Kalman filter residual e_kIncluding pseudorange residuals pe_kAnd pseudorange rate residualsThe expression is as follows: e.g. of the type_k＝z_k-H_kx_k/k-1；

Step 2.2: updating a detection threshold value according to residual error data stored when no deception jamming exists, specifically: selecting window capacity according to the residual variance discrete degree and the calculated amount, and updating the detection threshold value in real time according to the set false alarm probability by using the pseudo-range and pseudo-range rate residual variance data which are stored when the detection threshold value is not subjected to deception interference;

step 2.3: updating data in the residual error sliding window, specifically: sliding window W ═ e with capacity m_k-m+1,e_k-m+2,…,e_k]Obtaining a sliding mean using the residual of the first m-1 epochAnd further obtaining a sliding variance, and updating data in the sliding window by each epoch through a shifting operation.

2. If the state is not established in the step 3, entering a corresponding detection program according to the previous epoch deception flag Dec _ flag of the satellite channel and the state of the isolation exit counter cntr specifically comprises the following steps:

step 3.1: if the Dec _ flag is equal to 0 or 1, entering an isolation detection program, otherwise, continuously judging whether an isolation exit counter cntr is 0, and if the cntr is not 0, executing a step 3.2; if cntr is 0, go to step 3.3;

step 3.2: the satellite is in an isolation exit stage and executes an isolation exit detection program;

step 3.3: the satellite is not spoofed during the past filtering process and a conventional detection procedure is performed.

3. Step 4, dynamic delay deception signal segmentation detection is adopted, and the specific steps of sequentially carrying out dynamic delay process detection and fixed delay process detection are as follows:

step 4.1: the dynamic time delay process detection specifically comprises the following steps: calculating a pseudo-range rate residual error variance, comparing the pseudo-range rate residual error variance with a pseudo-range rate residual error variance threshold, if the detected quantity is larger than the threshold, indicating that a dynamic time delay process exists and dynamic time delay forwarding type deception jamming exists, setting a deception flag Dec _ flag to be 1, assigning the deception flag Dec _ flag to a maximum count value set by a cntr of an isolation exit counter, and ending; if the detection quantity is smaller than the threshold value, the dynamic time delay process does not exist, and the step 4.2 is executed;

step 4.2: the fixed time delay process detection specifically comprises the following steps: calculating a pseudo-range residual error variance, comparing the pseudo-range residual error variance with a pseudo-range residual error variance threshold, if the detected quantity is larger than the threshold, indicating that a fixed time delay process exists and fixed time delay forwarding type deception interference exists, setting a deception flag Dec _ flag to be 1, assigning a maximum count value set by a cntr of an isolation exit counter, and ending; if the detection quantity is smaller than the threshold value, the forwarding type deception jamming does not exist, and a step 4.3 is executed;

step 4.3: when the deception jamming is not detected, corresponding operation is carried out on the isolation exit counter, and the method specifically comprises the following steps: executing a conventional detection program, resetting an isolation exit counter to zero, and setting a deception flag Dec _ flag to 0; executing an isolation exit detection program, and subtracting 1 from the isolation exit counter each time until the isolation exit counter returns to zero, wherein a deception flag Dec _ flag is set to 0; and executing an isolation detection program, giving the maximum value set by the isolation exit counter, and setting a deception flag Dec _ flag to be 0.

4. In the step 1, GNSS receiver navigation parameters and SINS navigation parameters are collected, and the data are preprocessed specifically as follows:

step 1.1: collecting GNSS receiver navigation parameters, comprising: time tag, satellite PRN number, carrier phase, pseudorange, doppler shift, signal strength, and ephemeris data;

step 1.2: acquiring SINS navigation parameters including specific force data, angular velocity data and a time tag updated each time by SINS;

step 1.3: preprocessing the acquired data, specifically: firstly, processing receiver observation data to obtain observation information, wherein the observation information comprises a time tag, a visible satellite PRN number, a pseudo range and a pseudo range rate; secondly, satellite position and speed calculation is carried out by extracting ephemeris parameters to obtain the three-dimensional position, speed, clock error and frequency drift of each visible satellite; and finally, carrying out time synchronization on the SINS navigation parameters and the GNSS receiver navigation parameters according to the same time tag.

5. The step 5 of obtaining a deception jamming detection result and rejecting satellite signals corresponding to the detected deception channel, and the obtained deception jamming detection and combined navigation positioning results are specifically as follows: isolating the deception interfered satellite channel, reconstructing a corresponding residual error matrix, a measurement noise covariance matrix and a gain matrix, combining navigation Kalman filtering end and state updating, and storing a current epoch deception detection result.

The invention has the beneficial effects that: aiming at the problem of detection of dynamic time delay forwarding type deception jamming, the invention introduces a strapdown inertial navigation system which is not interfered by the outside to form a GNSS/SINS tightly-combined navigation system, decomposes a once complete dynamic time delay forwarding type deception jamming process into a dynamic time delay process and a fixed time delay process by analyzing the dynamic time delay characteristics of tightly-combined pseudo range and pseudo range rate residual error, provides a tightly-combined navigation forwarding type deception jamming detection method based on the residual dynamic time delay characteristics, and realizes the real-time detection of the dynamic time delay forwarding type deception jamming.

The method utilizes the dynamic time delay characteristic of tightly combined pseudo range and pseudo range rate residual to design the detection amount and the detection flow, utilizes the probability statistical characteristic of residual variance to design the detection threshold, and can effectively detect the dynamic time delay forwarding type deception jamming of which the code phase offset rate is not lower than 0.1 chip/s.

Drawings

Fig. 1 is an overall flowchart of a spoofed interference detection method according to the present invention.

Fig. 2 is a flowchart of a conventional detection procedure.

Fig. 3 is a flowchart of the isolation detection procedure.

Fig. 4 is a flowchart of the isolated exit detection procedure.

Fig. 5 shows a pseudorange residual variance change (sliding window capacity m is 10) when there is no forward spoofing interference.

Fig. 6 shows a pseudorange residual variance change (sliding window capacity m is 50) without forwarding spoofing interference.

Fig. 7 shows a pseudorange residual variance change (sliding window capacity m is 100) without forwarding spoofing interference.

Fig. 8 shows a change of a pseudorange rate residual variance without the repeater spoofing interference (the sliding window capacity m is 10).

Fig. 9 shows a change of a pseudorange rate residual variance without the repeater spoofing interference (the sliding window capacity m is 50).

Fig. 10 shows a change of a pseudorange rate residual variance without the repeater spoofing interference (the sliding window capacity m is 100).

FIG. 11 is a pseudorange residual variance probability statistic.

Fig. 12 is a pseudorange rate residual variance probability statistic.

Fig. 13 shows the dynamic delay forwarding spoofing interference pseudoranges and pseudorange rate error changes.

Fig. 14 shows the PRN1 continuous dynamic delay spoofing signal detection results.

Fig. 15 shows the detection result of the dynamic delay spoofed signal at the PRN9 stage.

Fig. 16 shows the PRN2 spoofing signal detection without dynamic delay.

Detailed Description

The invention is further described with reference to the drawings and the detailed description.

With reference to fig. 1 to 4, the embodiment of the present invention includes the following steps:

the method comprises the following steps: the method comprises the following steps of collecting GNSS receiver navigation parameters and SINS navigation parameters, and preprocessing data, wherein the steps specifically comprise:

1.1 collecting navigation parameters of the GNSS receiver.

1.2, acquiring SINS navigation parameters.

1.3 preprocessing the collected data.

Step two: updating data in a residual sliding window, and updating a detection threshold according to residual variance data stored when no deception jamming exists, wherein the method specifically comprises the following steps:

2.1 obtaining the pseudorange and pseudorange rate residuals for the current epoch.

2.2 updating the detection threshold based on residual variance data stored in the absence of spoofing interference

2.3 updating residual within-sliding-window data

Step three: if the number num of the effective data in the residual sliding window is less than the window capacity m, no detection condition is provided, and the detection program is not entered for the moment; otherwise, entering a corresponding detection program according to a previous epoch deception flag Dec _ flag of the satellite channel and the state of the isolation exit counter cntr, wherein the detection program specifically comprises the following steps:

3.1 if the number num of the effective data in the residual sliding window is less than the window capacity m, temporarily not entering a detection program; otherwise, entering a corresponding detection program according to the deception flag Dec _ flag of each channel of the previous epoch and the cntr state of the isolation exit counter.

3.2 if Dec _ flag is 1, entering an isolation detection program, otherwise, continuously judging whether an isolation exit counter cntr is 0.

3.3 if cntr is not 0, it means that the satellite is in the isolated exit phase, and the isolated exit detection procedure needs to be executed.

3.4 if cntr is 0, it means that the satellite is not deceptively interfered in the past 50 times of filtering processes, and a "conventional detection procedure" needs to be executed.

Step four: according to the design idea of the dynamic time delay deception signal segmentation detection, the dynamic time delay process detection and the fixed time delay process detection are sequentially carried out, and the method specifically comprises the following steps:

4.1 dynamic delay process detection.

4.2 fixed delay process detection.

4.3 when no spoofing interference is detected, the three detection programs need to correspondingly operate the isolation exit counter.

Step five: obtaining a deception jamming detection result and eliminating satellite signals corresponding to the detected deception channels, specifically comprising:

and 5.1, rejecting the channel and the corresponding satellite which are detected to be deceptive.

And 5.2, obtaining a deception jamming detection and combined navigation positioning result.

Step six: updating the epoch information, and repeatedly executing the steps from one to five until all epochs are processed.

In step 1.1, the method for collecting the navigation parameters of the GNSS receiver comprises the following steps: the observation data (including time tag, satellite PRN number, carrier phase, pseudorange, doppler shift, signal strength, etc. observation information) and ephemeris data are read in the RINEX3.02 format.

In step 1.2, the method for collecting the specific force data and the angular velocity data output by the SINS comprises the following steps: and acquiring specific force data and angular velocity data output by the SINS and a time tag updated every time by the SINS.

In step 1.3, the method for preprocessing the collected data comprises the following steps: firstly, simply processing observation data of a receiver, and directly obtaining observation information such as a time tag, a visible satellite PRN (pseudo-random number), a pseudo range rate and the like; secondly, extracting ephemeris parameters and resolving satellite position and velocity to obtain information such as three-dimensional position, velocity, clock error, frequency drift and the like of each visible satellite; and finally, carrying out time synchronization on the SINS navigation parameters and the GNSS receiver navigation parameters according to the same time tag.

In step 2.1, the method for obtaining the pseudo range and the pseudo range rate residual error of the current epoch comprises the following steps: the expression of the GNSS/SINS tightly combined navigation system after the piecewise linearization processing is as follows: x is the number of_k＝Φ_k/k-1x_k-1+Γ_k-1w_k-1And z_k＝H_kx_k+v_k. In the formula, x_kIs a state vector; phi_k/k-1A one-step state transition matrix; gamma-shaped_k-1Is a system noise matrix; z is a radical of_kIs a vector of measured values; h_kIs a measurement matrix; w is a_k-1And v_kAre zero-mean white noise vectors that are uncorrelated. Tightly combined system Kalman filtering residual e_kIncluding pseudorange residuals pe_kAnd pseudorange rate residualsThe expression is as follows: e.g. of the type_k＝z_k-H_kx_k/k-1。

In step 2.2, the method for updating the detection threshold according to the residual error data stored when no deception jamming exists comprises the following steps: the degree of residual variance dispersion decreases with increasing window capacity, but too much window capacity increases the amount of computation. The window capacity can be taken to be 50. In practical application, the pseudorange and pseudorange rate residual variance data stored when the pseudorange and the pseudorange rate residual variance data are not subjected to deception jamming are used, and the detection threshold value is updated in real time according to the set false alarm probability.

In step 2.3, the method for updating data in the residual error sliding window comprises the following steps: sliding window W ═ e with capacity m_k-m+1,e_k-m+2,…,e_k]The residual error of the first m-1 epoch is used to obtain the sliding mean valueAnd further obtaining a sliding variance, and updating data in the sliding window by each epoch through a shifting operation.

In step 3.1, the method for judging whether to enter the detection program comprises the following steps: and judging whether the quantity of available data in the residual sliding window is less than the window capacity, if so, temporarily not entering a detection program, and otherwise, entering the detection program.

In step 3.2, the method for judging whether to enter the isolation detection program comprises the following steps: and judging whether the cheating mark is 1, if so, entering an isolation detection program, and otherwise, further judging whether an isolation exit counter is 0.

In step 3.3, the method for entering the isolation exit detection program is judged: and judging whether the isolation exit counter is 0 or not on the premise that the cheating flag is 0, and if not, entering an isolation exit detection program.

In step 3.4, the method for entering the conventional detection program is judged: and judging whether the isolation exit counter is 0 or not on the premise that the cheating flag is 0, and entering a conventional detection program if the isolation exit counter is 0.

In step 4.1, the method for detecting the dynamic time delay process comprises the following steps: by comparing the dynamic time delay characteristics of the pseudo range and the pseudo range rate, the pseudo range error changes slowly and the pseudo range rate error changes rapidly under the effect of the dynamic time delay deception signal. Therefore, the method can carry out segmented detection on the dynamic time delay forwarding type deception jamming, and equate the dynamic time delay forwarding type deception jamming process into a dynamic time delay process and a fixed time delay process. In the dynamic time delay process, the characteristic of the mutation of the pseudo range rate is used for detection, in the fixed time delay process, the pseudo range difference accumulated in the dynamic time delay process is used for detection, and therefore the deception detection algorithm is designed by respectively using the dynamic time delay characteristics of the pseudo range and the pseudo range rate in different stages.

In the detection stage of the dynamic time delay process, calculating a pseudo-range rate residual error variance, comparing the pseudo-range rate residual error variance with a pseudo-range rate residual error variance threshold, if the detection amount is larger than the threshold, indicating that the dynamic time delay process exists and dynamic time delay forwarding type deception jamming exists, setting a deception flag Dec _ flag to be 1, and giving the deception flag Deck to a maximum count value of a cntr of an isolation exit counter 50; if the detection quantity is smaller than the threshold value, the dynamic time delay process does not exist, but the fixed time delay process detection is needed to be further carried out to judge whether the deception jamming exists.

In step 4.2, the fixed time delay process detection method comprises the following steps: and in the detection stage of the fixed time delay process, calculating the variance of the pseudo-range residual error, and comparing the variance with the threshold of the pseudo-range residual error. If the detection quantity is larger than the threshold value, the fixed time delay process exists, the forward type deception jamming exists, a deception flag Dec _ flag is set to be 1, and the deception flag Dec _ flag is given to a maximum count value 50 of a cntr of an isolation exit counter; and if the detection quantity is smaller than the threshold value, the repeater type deception jamming does not exist.

In step 4.3, when no deception jamming is detected, three methods for performing corresponding operations on the isolation exit counter by the detection program are as follows: the conventional detection program does not relate to the problem of isolation exit, so that an isolation exit counter is directly reset to zero; the isolation exit detection program needs to ensure that the satellite signal which is just recovered to be normal has no deception jamming influence in the last 50 times of filtering processes, so that the operation of subtracting 1 is adopted for each time until the isolation exit counter returns to zero; the isolation detection program does not detect the spoofed interference, that is, it determines that the current satellite signal is normal, and gives the maximum count value 50 to the isolation exit counter for the subsequent execution of the isolation exit program.

In step 5.1, the method for eliminating the channel detected as deception and the corresponding satellite comprises the following steps: and isolating the satellite channels subjected to deception interference, and reconstructing corresponding residual error matrixes, measurement noise covariance matrixes and gain matrixes.

In step 5.2, the method for obtaining the deception jamming detection and combined navigation positioning result comprises the following steps: and finishing the integrated navigation Kalman filtering, updating the state, and storing the current epoch deception detection result.

Examples are given below with specific parameters:

the steps of the example are as follows:

step 1: and acquiring navigation parameters of the GNSS receiver and navigation parameters of the SINS, and preprocessing the data.

Step 2: and updating data in the residual sliding window, and updating the detection threshold according to residual variance data stored when no deception jamming exists.

And step 3: if the number num of the effective data in the residual sliding window is less than the window capacity m, no detection condition is provided, and the detection program is not entered for the moment; otherwise, entering a corresponding detection program according to a previous epoch deception flag Dec _ flag of the satellite channel and the cntr state of the isolation exit counter.

And 4, step 4: and according to the design idea of the dynamic time delay deception signal segmentation detection, sequentially carrying out dynamic time delay process detection and fixed time delay process detection.

And 5: and obtaining a deception jamming detection result and eliminating the satellite signals corresponding to the detected deception channels.

Step 6: updating the epoch information, and repeatedly executing the steps (1) to (5) until all epochs are processed.

The invention takes the observation data output by the GNSS receiver and the specific force and angular velocity data output by the medium-precision optical fiber inertial navigation as examples to explain the specific processing process in detail. A dynamic time delay forwarding type spoofing interference person in the data is added, and specific information of the data is shown in table 1:

TABLE 1 dynamic delay scenario delay parameters

In the step 1, the total time length of SINS data is 600 s; the total time length of the GNSS receiver data is 590.9 s; the combined navigation initiation processing epoch is the 91 st epoch.

In step 2, taking PRN1 as an example, when residual sliding windows are respectively set to 10, 50, and 100, the variation situations of pseudorange and pseudorange rate residual variance under no repeater-like spoofing interference are shown in fig. 5 to 10, and the capacity of the residual sliding window is set to m equal to 50 by comprehensive consideration; fig. 11 and 12 show probability density and cumulative distribution curves of pseudorange and pseudorange rate residual variance, respectively, without the effects of spoofing interference. When the detection probability is higher than 99%, the pseudorange residual detection threshold may be set to 4.65m²At this threshold, the false alarm probability is 1.5 × 10^-3(ii) a When the detection probability is higher than 99%, the pseudorange rate residual detection threshold may be set to 0.10m²/s²At this threshold, the false alarm probability is 1.2 × 10^-3。

In the step 3, the capacity of the sliding window is preset to be m, if the satellite serial number i is larger than the number n of visible satellites, it is indicated that all the visible satellite channels are detected, and the detection program is quitted; otherwise, the execution is continued, and the pseudo range rate residual error sliding window of the ith satellite are updated. If the number num of the effective data in the residual sliding window is less than the window capacity m, the detection program is not entered temporarily, otherwise, the corresponding detection program is entered according to the deception flag Dec _ flag of each channel of the previous epoch and the cntr state of the isolation exit counter. The flow charts of the conventional detection procedure, the isolation detection procedure, and the isolation exit detection procedure are shown in fig. 2, 3, and 4. When the deception flag Dec _ flag is detected to be 1, it is indicated that the satellite has been detected to have deception interference in the last kalman filtering process, and then an isolation detection program is entered to perform deception interference detection, otherwise, it is required to further determine whether the cntr of the isolation exit counter is 0. If cntr is not 0, it indicates that the satellite is currently in the isolated exit stage, and an isolated exit detection program needs to be executed; if cntr is 0, it means that the satellite has not been spoofed and interfered in at least the past 50 filtering processes, and only the "conventional detection procedure" needs to be executed.

In step 4, taking PRN1 as an example, the dynamic delay characteristics of the pseudorange and pseudorange rate errors under dynamic delay-forwarded spoofing interference are shown in fig. 13. PseudorangeThe error slowly increases at a rate of about 14.7m/s to about 439.9m and does not continue to increase; the pseudorange rate error is abruptly changed to about 14.7m/s over 2 epochs and returns to normal after the pseudorange error reaches about 439.9 m. By comparing the dynamic time delay characteristics of the pseudo range and the pseudo range rate, the design of the cheat detection algorithm can be effectively developed by equating the dynamic time delay forwarding type cheat interference process into a dynamic time delay process and a fixed time delay process. The detection procedure is illustrated in fig. 2. If MV _ raw _ dot>T₁If the dynamic delay process exists, the Dec _ flag is 1 and the cntr is 50; if less than the threshold T₁Then, whether a fixed time delay process exists needs to be further judged; if MV _ raw>T₀If so, it indicates that a fixed delay process exists, and it needs to make Dec _ flag equal to 1 and cntr equal to 50; if MV _ raw<T₀Then it indicates that the detection algorithm has not detected spoofing interference.

Step 5, isolating the satellite channel subjected to deception interference on the premise of detecting deception interference, and reconstructing a corresponding residual error matrix, a measurement noise covariance matrix and a gain matrix; and finishing the state updating and storing the current epoch deception detection result.

In step 6, updating the epoch information KF _ cntr ═ KF _ cntr +1, and finishing all epochs by loop processing. The PRN1 continuous dynamic delay spoofed signal detection results are shown in fig. 14. The PRN9 stage dynamic delay spoofing signal detection results are shown in fig. 15. The PRN2 spoof signal detection results without dynamic delay are shown in fig. 16.

According to the detection result of the dynamic time delay forwarding type deception jamming, the method can effectively detect the dynamic time delay forwarding type deception jamming with the code phase offset rate not lower than 0.1chip/s in real time.

In summary, the invention relates to a GNSS/SINS tightly-combined navigation forwarding type deception jamming detection method, and belongs to the technical field of satellite navigation deception detection. The traditional detection method identifies the deception signal according to pseudo-range mutation caused by the forwarding type deception interference, can detect the fixed time delay forwarding type deception interference, but has no effect on the dynamic time delay forwarding type deception interference. Aiming at the problem of detection of dynamic delay forwarding type deception interference, the invention provides a method for detecting the close-coupled navigation forwarding type deception interference based on residual dynamic delay characteristics. The invention comprises the following steps: (1) acquiring GNSS receiver navigation parameters and SINS navigation parameters, and preprocessing data; (2) updating data in a residual sliding window, and updating a detection threshold according to residual variance data stored when no deception interference exists; (3) and (3) entering a corresponding detection program (4) according to the deception condition of each channel of the previous epoch, sequentially carrying out dynamic time delay process detection and fixed time delay process detection (5) according to the design concept of dynamic time delay deception signal segmentation detection to obtain a deception interference detection result, removing (6) satellite signals corresponding to the detected deception channels to update epoch information, and repeatedly executing the steps (1) to (5) until all epochs are processed. The verification proves that the method can effectively detect the dynamic time delay forwarding type deception jamming with the code phase offset rate not lower than 0.1chip/s in real time.