CN115015979A - Navigation signal receiving and processing system and method based on self-adaptive dynamic switching - Google Patents

Abstract

The invention relates to a navigation signal receiving and processing system and a method based on self-adaptive dynamic switching, comprising the following steps: the system comprises a receiver terminal self-adaptive dynamic switching receiving processing system, a receiver pseudo-range resolving system, a receiver position data processing system, an information transmission system and an information data storage system; compared with the prior art, the method is suitable for the motion speed dynamic conditions of different receiving resolving points, and improves the universality of satellite navigation signal baseband receiving processing; based on the high-speed transmission characteristic of 5G, the method develops services for the comprehensive application terminal based on the satellite navigation system, realizes the functions of resolving the position and the movement speed of the receiving and resolving point in any applicable scene, and constructs a large database of the information of the position and the movement speed of the receiving and resolving point.

Description

A navigation signal receiving and processing system and method based on adaptive dynamic switching

technical field

The present invention relates to the technical field of navigation and positioning, a baseband algorithm for navigation signal processing, and in particular, to a system and method for receiving and processing navigation signals based on adaptive dynamic switching.

Background technique

Satellite navigation and positioning, as an important application point of the basic space-time information network, provides people with accurate location information services. The satellite navigation text data and pseudorange information obtained by GNSS transmission signals are used to calculate the accuracy and accuracy of coordinate positions to ensure high accuracy. Accurate location location services. The diversity and complexity of applications and applicable scenarios have changed from the original basic location information to the universality under different dynamic state conditions. In the future, diversified and complex receiving scenarios will receive and process a single static and dynamic navigation signal. The plan puts forward requirements. In order to meet the needs of scenario-based, substantive, and refined applications, and to meet the establishment and development of a large database of precise location and motion speed information, it is an inevitable trend to transform from static and dynamic to the application of diverse and complex scenarios. Reasonable adaptive and dynamic switching navigation signal reception and processing solutions are particularly important and necessary.

At present, with the development of various industries and industries in society, the dependence on PNT (positioning, navigation and timing) information services has begun to take shape; typical application scenarios represented by modern industries, service industries, and commerce and trade fields have emerged in large-scale and explosive markets. Demand, the demand for PNT information services has changed from ordinary precision to higher precision, from simple open scenes to complex scenes (occlusion, multipath, electromagnetic interference), and from static to dynamic. Demand development, the old common precision, simple open scene, static method, etc., cannot meet the needs of scene-based, refined, and complete. The transformation of PNT information services to more comprehensive and applicable indicators is an inevitable development.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a navigation signal receiving and processing system and method based on adaptive dynamic switching, so as to solve the above-mentioned problems in the background art.

The present invention proposes a reasonable adaptive and dynamic switching navigation signal receiving and processing solution; aiming at the problems that the tracking loop may lose lock, the tracking error is too large, and the stable tracking of a single loop may be caused by the motion state of the object being dynamic, static and dynamic conversion, etc., Give full play to the advantages of adaptive dynamic switching tracking loop to ensure accurate positioning under dynamic, static and dynamic transformation of object motion state; break through the unification and transmission of space-time reference based on satellite navigation system, the construction of large data feature library of precise position and motion speed information, and the Key technologies such as update, pan-source seamless adaptive dynamic switching navigation signal reception and processing, and Beidou precise spatiotemporal information lightweight service.

To achieve the above object, the present invention provides the following technical solutions:

A navigation signal receiving and processing system based on adaptive dynamic switching, comprising: a receiver terminal adaptive dynamic switching receiving and processing system, a receiver pseudorange solution system, a receiver position data processing system, an information transmission system and an information data storage system ;

Wherein, the receiver terminal adaptive dynamic switching reception processing system uses overhead visible satellites, selects landmark points as receiving and solving points, and receives, processes, and navigates the multi-mode and multi-frequency GNSS satellite navigation signals transmitted by overhead visible satellites. Extraction of telegram data, baseband calculation, and acquisition of visual receiving satellite information data at the receiving and solving point;

The receiver pseudo-range calculation system performs information data calculation and extraction on the pseudo-range information of the receiving and solving point and the overhead visible satellite, and obtains the precise distance information data between each visible receiving satellite and the receiving and calculating point. ; Calculate and extract the Doppler frequency shift amount of the tracking processing of the receiver terminal adaptive dynamic switching receiving processing system;

The receiver position data processing system aggregates the navigation message data information provided by the receiver terminal adaptive dynamic switching reception processing system, and simultaneously aggregates the precise distance information data and Doppler frequency shift information data provided by the receiver pseudorange solution system. , obtain the characteristic matrix of position solution and motion speed solution, and obtain the precise coordinate position information data and motion speed information data of the received solution point by solution;

The information transmission system sends to the information data storage system the precise coordinate position information data of the received solution point and the movement speed information data obtained by the solution;

The information data storage system organizes and archives the precise coordinate position information data of the receiving and solving point and the moving speed information data transmitted by the information transmission system, and constructs a large database of the receiving and solving point position and moving speed information.

A method for constructing a navigation signal receiving and processing based on adaptive dynamic switching, wherein a navigation signal receiving and processing system receives a GNSS signal transmitted by an overhead visible satellite, comprising the following steps:

Step S1, select the object point as the receiving and solving point, perform receiving processing, navigation message data extraction, baseband solving on the multi-mode and multi-frequency GNSS satellite navigation signals transmitted by the overhead visible satellite, and obtain the receiving and solving point visual receiving satellite. information data;

Step S2, solve and extract the pseudo-range information data between the receiving and solving point and the overhead visible satellite, and obtain the precise distance information data between each visible receiving satellite and the receiving and solving point; Adapt to the Doppler frequency shift in the tracking process of the dynamic switching receiving and processing system;

In step S3, the extracted navigation text data information, Doppler frequency shift amount and precise distance information data are unifiedly aggregated to obtain the position solution and motion speed solution feature matrix, and the solution obtains the precise coordinate position information data of the received solution point, Movement speed information data;

Step S4, sending the precise coordinate position information data and motion speed information data of the received solution point obtained by the solution to the back-end information data storage system;

In step S5, the back-end information data storage system uniformly aggregates and transmits the precise coordinate position information data and motion speed information data, and archives them according to an effective database data management method, and constructs a large database of receiving and solving point positions and motion speed information.

Preferably according to the present invention, the specific implementation process of step S1 includes:

Step S1.1: Receive and process GNSS satellite navigation signals

Receive the multi-mode and multi-frequency GNSS satellite navigation signal transmitted by the overhead visible satellite, and convert it into digital signal data after digital frequency conversion, sampling and quantization;

Step S1.2: Acquire tracking processing data

The receiving and solving point is based on the real-time acquisition of the moving speed information data of the receiving and solving point, and the adaptive and dynamic switching tracking loop solution method is used to track the GNSS satellite navigation signal with high precision and accuracy;

The movement speed information data refers to the real-time movement speed of the carrier when the receiver terminal adaptive dynamic switching receiving processing system receives the GNSS satellite navigation signal; in the static state, the true value of the movement speed of the receiving solution point is 0;

Use the Doppler frequency shift in the tracking process for motion velocity measurement and calculation to obtain motion velocity information data; the solution equation is shown in formula (I):

λD _i =ρ _i +cidt _u -cidt _i -I _i +T _i +ε (I)

In formula (I), λ is the carrier frequency wavelength, D _i is the observed value of the Doppler frequency shift of the i-th observation satellite, ρ _i is the rate of change of the pseudo-range observation, c is the speed of light, and dt _u and dt _i are the receiving The rate of change of the clock error of the terminal and the rate of change of the clock error of the i-th observation satellite, I _i and T _i are the rate of change of the ionosphere and troposphere delays, respectively, and ε is the observation noise;

The direction cosine (e ^xi _i , e ^yi , e ^zi ) between the receiving and solving point (X _u , _Yu , Z _u ) and the observation satellite (X _i , Y _i , Z _i ) is shown in formula (II), formula (III), shown in formula (IV):

The rate of change of pseudorange observations is shown in formula (V):

为第i颗观测卫星运行速度，

为接收解算点运动速度，[e^xi e^yie^zi]为接收解算点与观测卫星i的方向余弦；In formula (V),

is the running speed of the i-th observation satellite,

is the movement speed of the receiving solution point, [e ^xi e ^yi e ^zi ] is the cosine of the direction between the receiving solution point and the observation satellite i;

The satellite position and satellite running speed are calculated from the navigation message data information; the approximate coordinate position of the receiving and solving point is obtained, then the moving speed of the receiving and solving point and the rate of change of the receiver clock error are unknowns to be determined; when 4 or more observation satellites are received, Construct a system of characteristic matrix equations, and solve the unknowns to be solved by the least squares method;

Step S1.3: extracting navigation message data through signal capture and tracking processing;

After the satellite navigation signal tracking process is completed, the real-time I branch component information obtained by the tracking loop demodulation is subjected to bit synchronization, frame synchronization, and parity check processing procedures, and the navigation message data is extracted bit by bit.

Further preferably, the specific implementation process of step S1.2 includes:

When the motion acceleration of the receiving and solving point is less than 5gm/s ² and the speed is less than 25m/s, the receiving and solving point adopts the tracking loop structure of the second-order frequency-locked loop assisted by the third-order phase-locked loop to receive and process the GNSS satellite navigation signal;

When the motion acceleration of the receiving and solving point is greater than 5gm/s ² and the speed is greater than 25m/s, the receiving and solving point adopts the extended Kalman filter tracking loop structure to receive and process the GNSS satellite navigation signal.

Preferably according to the present invention, the specific implementation process of step S2 includes:

Step S2.1: Acquire pseudorange information data, that is, pseudorange observation quantity information

The pseudo-range observation information is obtained by using code correlation technology, and a local replica code with the same structure as the observation satellite ranging code is generated; the receiving and solving point is divided into multiple satellite navigation signal receiving channels, and each satellite navigation signal receiving channel continuously tracks a separate Satellite navigation signals, maintain stable and continuous tracking of satellite navigation signals; use the tracking results and frame synchronization header position information to obtain pseudo-range observation information by relative measurement:

1) Taking the observation satellite closest to the receiving and solving point as the reference satellite, and taking the position moment of the rising edge of the frame synchronization header as the moment of obtaining the pseudo-range observation quantity information of each observation satellite;

2) Calculate the relative pseudorange Δρ _i between each observation satellite and the reference satellite, as shown in formula (VI):

为第i颗观测卫星帧同步头上升跳变沿位置时刻；In formula (VI),

is the position moment of the rising edge of the frame synchronization header of the i-th observation satellite;

3) Observing satellite pseudo-range observation quantity information ρ _i , as shown in formula (VII):

为接收解算点内置GNSS卫星导航信号最小传输时间，与光速c相乘为卫星导航信号最小传输距离，各观测卫星伪距观测量信息为最小传输距离与相对伪距的累积；In formula (VII), dt is the satellite clock error parameter,

In order to receive the minimum transmission time of the built-in GNSS satellite navigation signal at the calculation point, the minimum transmission distance of the satellite navigation signal is multiplied by the speed of light c, and the pseudorange observation information of each observation satellite is the accumulation of the minimum transmission distance and the relative pseudorange;

Step S2.2: Obtain the Doppler frequency shift amount, that is, the Doppler frequency shift observation amount

The obtained Doppler frequency shift observation is the difference between the tracked carrier frequency and the nominal carrier frequency of the satellite navigation signal.

Preferably according to the present invention, the specific implementation process of step S3 is as follows:

Step S3.1: Calculate the position information data

Through the extracted navigation message data information, pseudo-range observation information and precise distance information data, the three-dimensional space position of the receiving solution point in the coordinate system is obtained:

The observation equation is shown in formula (VIII):

表示第i颗观测卫星大气延迟误差；In formula (VIII), ρ ⁱ represents the pseudo-range observation amount of the i-th observation satellite, (X _j , Y _j , Z _j ) represents the three-dimensional space position of the receiving point in the coordinate system, (Xi,Yi,Zi) represents the i-th observation satellite, dt represents the receiver terminal clock error, dT ⁱ represents the i-th observation satellite clock error,

represents the atmospheric delay error of the i-th observation satellite;

The coordinate position of the observation satellite, the satellite clock error, and the atmospheric delay error are obtained from the navigation message data information, and the full rank condition of the observation equation (VIII) is satisfied. Obtain the position information data (X _j , Y _j , Z _j ) of the received solution point and the receiver terminal clock error.

Step S3.2: Calculation of motion speed information data

Through the extracted navigation text data information and tracking processing data, the movement speed of the receiving solution point in the coordinate system is obtained; the observation equation is shown in formula (IX):

D=e ⁱ (vi -v ^j )+b+δ _i ⁽ IX)

为第i颗观测卫星多普勒频移量，λ为接收GNSS卫星导航信号载波频率波长，vⁱ为第i颗观测卫星运动速度，由提取的导航电文数据获得，v_j为接收解算点运动速度信息数据，其对应坐标系下的3个方向运动速度分别为[v_xj,v_yj,v_zj]^T，eⁱ为接收解算点与观测卫星之间连线方向的余弦参数变量，其3个方向参数变量分别为：In formula (IX), D is the Doppler frequency shift,

is the Doppler frequency shift of the i-th observation satellite, λ is the carrier frequency wavelength of the received GNSS satellite navigation signal, v ⁱ is the motion speed of the i-th observation satellite, obtained from the extracted navigation message data, and v _j is the receiving solution point Movement velocity information data, the movement velocity in the corresponding three directions in the coordinate system is [v _xj , v _yj , v _zj ] ^T , e ⁱ is the cosine parameter variable of the connection direction between the receiving solution point and the observation satellite, Its three direction parameter variables are:

(X _j , Y _j , Z _j ) represents the three-dimensional space position of the receiving solution point in the coordinate system, (X ⁱ , Y ⁱ , Z ⁱ ) represents the i-th observation satellite, and b is the receiver terminal clock error rate of change , δ ⁱ is the error term caused by various factors such as the observation satellite clock error, ionospheric error, and tropospheric error;

Satisfying the full rank condition of the observation equation (IX) means receiving and processing the GNSS satellite navigation signal data transmitted by 4 or more observation satellites, and obtaining the motion speed information data of the receiving and solving point by solving the equation (I).

The beneficial effects of the present invention are:

Compared with the prior art, the present invention provides a navigation signal receiving and processing system and method based on adaptive dynamic switching, which is suitable for the dynamic conditions of motion speed of different receiving and solving points, and enhances the universality of satellite navigation signal baseband receiving and processing; Based on the high-speed transmission characteristics of 5G, it provides services for the comprehensive application terminal based on the satellite navigation system, realizes the function of calculating the position of the receiving and solving point and the moving speed in any applicable scenario, and builds a large database of information on the position and moving speed of the receiving and solving point.

Description of drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings required in the technical solutions of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained from these drawings without creative effort.

FIG. 1 is a block diagram of a navigation signal receiving and processing system based on adaptive dynamic switching according to an embodiment of the present invention.

FIG. 2 is a schematic flowchart of a navigation signal receiving process based on adaptive dynamic handover according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a process flow of receiving and processing satellite navigation signals according to an embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a tracking loop of a second-order frequency-locked loop assisted by a third-order phase-locked loop according to an embodiment of the present invention.

FIG. 5 is a schematic structural diagram of an extended Kalman filter tracking loop according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

A navigation signal receiving and processing system based on adaptive dynamic switching, as shown in Figure 1, includes: a receiver terminal adaptive dynamic switching receiving and processing system, a receiver pseudorange solution system, a receiver position data processing system, and an information transmission system. system and information data storage system;

Among them, the receiver terminal adaptive dynamic switching receiving processing system uses the overhead visible satellites in a certain receiving scene area, selects the object points as the receiving and solving points, and performs multi-mode and multi-frequency GNSS satellite navigation signals transmitted by the overhead visible satellites. Reception processing, navigation message data extraction, baseband calculation, and acquisition of visible satellite information data at reception and calculation points;

The receiver pseudo-range calculation system performs information data calculation and extraction on the pseudo-range information of the receiving and solving point and the overhead visible satellite, and obtains the accurate distance information data between each visible receiving satellite and the receiving and calculating point; Receiver terminal adaptive dynamic switching receiving processing system tracking processing Doppler frequency shift calculation and extraction; prepare for the receiver position data processing system to obtain the position information and motion speed information of the receiving and solving point;

The receiver position data processing system aggregates the navigation message data information provided by the receiver terminal adaptive dynamic switching reception processing system in a certain reception scene area, and at the same time aggregates the precise distance information provided by the receiver pseudorange solution system in a certain reception scene area data, Doppler frequency shift information data, obtain the characteristic matrix of position calculation and motion speed calculation, and obtain the precise coordinate position information data and motion speed information data of the receiving and calculation point through calculation;

The information transmission system utilizes the high-speed transmission characteristics of 5G to send the precise coordinate position information data and motion speed information data of the received solution point obtained by the solution to the information data storage system;

The information data storage system is deployed in the system terminal server or workstation, and the precise coordinate position information data and motion speed information data of the receiving and solving point transmitted by the information transmission system are regularly archived according to the effective database data management method, and the position of the receiving and solving point is constructed. Large database with movement speed information.

Example 2

A navigation signal reception and processing construction method based on adaptive dynamic switching, the navigation signal reception and processing system described in Embodiment 1 receives the overhead visible satellite to transmit GNSS satellite navigation signals, as shown in Figure 2 and Figure 3, including the following steps:

The Samsung seven-band (including the above four-star and thirteen-band) receiving antenna is used to connect with the navigation signal receiving and processing system for adaptive dynamic switching of the receiver terminal. It is worth noting that the four-star and thirteen-frequency receiving antenna is used to solve the The results of position information data and motion speed information data are better than Samsung's seven-frequency receiving antenna, which is related to the multi-mode and multi-frequency GNSS satellite navigation signal data that can participate in the position and motion speed calculation;

Step S1: In a certain receiving scene area, select a feature point as a receiving and solving point, and perform receiving processing, navigation text data extraction, and baseband solving on the multi-mode and multi-frequency GNSS satellite navigation signals transmitted by the overhead visible satellites, and obtain the received signal. The solution point can receive the satellite information data visually;

Step S2, solve and extract the pseudo-range information data of the overhead visible satellites in a certain receiving scene area with the receiving and solving point, and obtain the precise distance information data between each corresponding visible receiving satellite and the receiving and solving point; Extracting the Doppler frequency shift in the tracking process of the receiver terminal adaptive dynamic switching receiving processing system; preparing for the receiver position data processing system to obtain the position information and motion speed information of the receiving solution point;

Step S3: Unified aggregation of the navigation message data information, Doppler frequency shift amount and precise distance information data extracted in a certain receiving scene area to obtain a position solution and a motion speed solution feature matrix, and obtain accurate receiving and solution points. Coordinate position information data, motion speed information data;

Step S4, using the high-speed transmission characteristics of 5G, send the precise coordinate position information data and motion speed information data of the received solution point obtained by the solution to the back-end information data storage system;

In step S5, the back-end information data storage system uniformly aggregates and transmits the precise coordinate position information data and motion speed information data, and archives them according to an effective database data management method, and constructs a large database of receiving and solving point positions and motion speed information.

Example 3

A method for constructing a navigation signal receiving and processing based on adaptive dynamic switching according to Embodiment 2, the difference is:

The specific implementation process of step S1 includes:

Step S1.1: Receive and process GNSS satellite navigation signals

The receiving antenna receives the multi-mode and multi-frequency GNSS satellite navigation signals transmitted by the overhead visible satellites in a certain receiving scene area, and transmits it into the receiver terminal adaptive dynamic switching receiving and processing system, which is digital signal data after digital frequency conversion, sampling and quantization;

Digital frequency conversion refers to: realizing the transfer of multi-mode and multi-frequency GNSS satellite navigation signals in the frequency domain, and down-converting the carrier frequency of multi-mode and multi-frequency GNSS satellite navigation signals from the nominal RF frequency to the intermediate frequency frequency;

Sampling refers to: digitally process the multi-mode and multi-frequency GNSS satellite navigation signals transmitted by the receiving observation satellite on the time continuous axis, and extract the corresponding instantaneous value of the signal amplitude at a certain time interval;

Quantization refers to the digital processing of the multi-mode and multi-frequency GNSS satellite navigation signals transmitted by the receiving observation satellite on the continuous axis of amplitude, and the quantized value is represented by a limited binary number, and the received signal data is digital signal data;

Step S1.2: Acquire tracking processing data

The receiving and solving point is based on the movement speed information data of the receiving and solving point acquired by the receiver position data processing system in real time, and the adaptive and dynamic switching tracking loop solution method is used to track the GNSS satellite navigation signal with high precision and accuracy. Preparing for the extraction step of the Puller frequency shift, it is worth noting that the tracking process selects the second-order FLL-assisted third-order PLL tracking loop structure when acquiring the receiver motion speed information data in the initial stage. In the case of information data, based on the motion speed information data, real-time adaptive and dynamic switching of the tracking loop structure to meet the needs of high-precision tracking and matching motion speed;

The movement speed information data refers to the real-time movement speed of the carrier when the receiver terminal adaptive dynamic switching receiving processing system receives the GNSS satellite navigation signal; in the static state, the true value of the movement speed of the receiving solution point is 0;

Use the Doppler frequency shift in the tracking process for motion velocity measurement and calculation to obtain motion velocity information data; the solution equation is shown in formula (I):

λD _i =ρ _i +c·dt _u -c·dt _i -I _i +T _i +ε (I)

In formula (I), λ is the carrier frequency wavelength, D _i is the observed value of the Doppler frequency shift of the i-th observation satellite, ρ _i is the rate of change of the pseudo-range observation, c is the speed of light, and dt _u and dt _i are the receiving The rate of change of the clock error of the terminal and the rate of change of the clock error of the i-th observation satellite, I _i and T _i are the rate of change of the ionosphere and troposphere delays, respectively, and ε is the observation noise;

The direction cosine (e ^xi _i , e ^yi , e ^zi ) between the receiving and solving point (X _u , _Yu , Z _u ) and the observation satellite (X _i , Y _i , Z _i ) is shown in formula (II), formula (III), shown in formula (IV):

The rate of change of pseudorange observations is shown in formula (V):

为第i颗观测卫星运行速度，

为接收解算点运动速度，[e^xi e^yie^zi]为接收解算点与观测卫星i的方向余弦；In formula (V),

is the running speed of the i-th observation satellite,

is the movement speed of the receiving solution point, [e ^xi e ^yi e ^zi ] is the cosine of the direction between the receiving solution point and the observation satellite i;

The magnitude of the change rate of the satellite clock error is 0.001ns/s, which can be ignored; the ionospheric and tropospheric delay change rates are ignored; the satellite position and satellite speed are calculated from the navigation message data information; the approximate coordinate position of the receiving point is obtained, then The motion speed of the receiving solution point and the receiver clock error rate of change are unknowns; receive 4 or more observation satellites, construct a characteristic matrix equation system, and solve the unknowns by the least squares method;

The specific implementation process of step S1.2 includes:

Adaptive dynamic switching means that within a certain receiving scene area, the motion speed information data of the receiving solution point calculated and extracted by the receiver position data processing system is used as the judgment basis. Tracking loop workaround during receive processing:

When the motion acceleration of the receiving and solving point is less than 5gm/s ² and the speed is less than 25m/s, the receiving and solving point adopts the tracking loop structure of the second-order frequency-locked loop (FLL) assisted by the third-order phase-locked loop (PLL) to receive and process GNSS satellite navigation signals;

The process of solving the motion acceleration of the receiving and solving point is as follows: on the basis of extracting the motion velocity sequence of the receiving and solving point, the acceleration sequence is obtained by the differential operation after curve fitting; the segmental velocity polynomial is obtained by using the M-order least square fitting method. , the derivation of the piecewise velocity polynomial is the acceleration sequence.

The frequency-locked loop (FLL) adopts a wider loop noise bandwidth and a shorter correlation accumulation time to meet the requirements of pulling the carrier frequency to the tracking frequency range and provides good dynamic tracking performance; the phase-locked loop (PLL) adopts a narrower The loop noise bandwidth and higher loop order can meet the requirements of high-precision tracking of the GNSS satellite navigation signal state and match its theoretical dynamic range; the tracking loop structure of the second-order frequency-locked loop assisted by the third-order phase-locked loop is adopted As shown in Figure 4.

When the motion acceleration of the receiver solution point is greater than 5gm/s ² and the velocity is greater than 25m/s, the receiver solution point adopts the extended Kalman filter (EKF) tracking loop structure to receive and process the GNSS satellite navigation signal.

The extended Kalman filter (EKF) is used to replace the tracking loop filter structure in Fig. 4, so that the carrier frequency can be pulled to the tracking frequency range, and the stability of the tracking loop can be satisfied. (FLL) auxiliary third-order phase-locked loop (PLL) tracking loop structure for higher tracking accuracy; Extended Kalman filter (EKF) tracking loop structure diagram is shown in Figure 5.

Step S1.3: Extract navigation message data through signal capture and tracking processing

Signal acquisition refers to: reading digital signal data, performing coarse synchronization (code correlation technology) processing between the received satellite navigation signal and the locally generated copy, and estimating the code phase and carrier frequency deviation;

Tracking processing refers to the process of synchronizing the changes of the code phase and carrier frequency in a finer manner than the acquisition; the carrier tracking loop and the code tracking loop estimate the offset of the carrier phase and the code phase in real time to achieve stability , synchronization, and continuous tracking to meet the demand for continuous demodulation of the input satellite navigation signal; the carrier tracking loop is generally a phase-locked loop, a frequency-locked loop to estimate the carrier phase offset, and the code tracking loop is generally a delay-locked loop estimation code Phase offset, to achieve precise synchronization of code phase and carrier frequency in independently divided tracking channels;

After the satellite navigation signal tracking process is completed, the real-time I branch component information obtained by the tracking loop demodulation is subjected to bit synchronization, frame synchronization, and parity check processing procedures, and the navigation message data is extracted bit by bit.

The real-time I branch component obtained by the tracking loop demodulation contains the message or secondary code information, which is accumulated, summed, and judged in turn, and processed by frame synchronization (correlation operation with the fixed frame synchronization header in the message or secondary code) , determine the position of the frame header sequence; obtain the synchronization result of the data component, decode the data component, so as to obtain the navigation message data information required for the navigation solution; read the corresponding message data format according to the interface control file (ICD) The ephemeris data information is converted from binary to decimal for calculation of satellite position, speed and other parameters; for different multi-mode and multi-frequency GNSS satellite navigation signals, the navigation message data is included for satellite orbit calculation. The semi-major axis, eccentricity, amplitude angle of perigee, ascending node right ascension, orbital inclination, mean perigee angle, ephemeris reference time, etc.

Navigation signal receiving and processing means that the receiving and solving point will receive the GNSS satellite navigation signals transmitted by the overhead visible satellites in a certain area of the scene, and perform related processing such as capturing, tracking, and demodulating the navigation text data.

Receiver pseudorange calculation refers to the collection of accurate distance information data between the overhead visible satellite and the receiver calculation point within a certain receiving scene area by the receiver calculation point, which is the pseudorange information data; Doppler frequency shift; prepare for the receiver position data processing system to calculate the position information and motion speed information of the receiving point.

Receiver position data processing refers to using the extracted navigation message data, accurate distance information, and Doppler frequency shift of the received and resolved points to construct a feature matrix for position calculation and motion speed calculation, and obtain its precise coordinate position and motion speed through calculation. information data.

The information transmission system and the information data storage system transmit and receive the precise coordinate position information data and motion speed information data of the solution points through 5G communication means, and cooperate with them to organize and archive them according to the effective database data management method to build a big data resource library of position and motion speed information.

Example 4

A method for constructing a navigation signal receiving and processing based on adaptive dynamic switching according to Embodiment 3, the difference is:

The specific implementation process of step S2 includes:

Step S2.1: Acquire pseudorange information data, that is, pseudorange observation quantity information

The pseudo-range observation information is obtained by using code correlation technology, and a local replica code with the same structure as the observation satellite ranging code is generated; the receiving and solving point is divided into multiple satellite navigation signal receiving channels, and each satellite navigation signal receiving channel continuously tracks a separate Satellite navigation signals, maintain stable and continuous tracking of satellite navigation signals; use the tracking results and frame synchronization header position information to obtain pseudo-range observation information by relative measurement:

1) Taking the observation satellite closest to the receiving and solving point as the reference satellite, and taking the position moment of the rising edge of the frame synchronization header as the moment of obtaining the pseudo-range observation quantity information of each observation satellite;

2) Calculate the relative pseudorange Δρ _i between each observation satellite and the reference satellite, as shown in formula (VI):

为第i颗观测卫星帧同步头上升跳变沿位置时刻；In formula (VI),

is the position moment of the rising edge of the frame synchronization header of the i-th observation satellite;

3) Observing satellite pseudo-range observation quantity information ρ _i , as shown in formula (VII):

为接收解算点内置GNSS卫星导航信号最小传输时间，与光速c相乘为卫星导航信号最小传输距离，各观测卫星伪距观测量信息为最小传输距离与相对伪距的累积；In formula (VII), dt is the satellite clock error parameter,

In order to receive the minimum transmission time of the built-in GNSS satellite navigation signal at the calculation point, the minimum transmission distance of the satellite navigation signal is multiplied by the speed of light c, and the pseudorange observation information of each observation satellite is the accumulation of the minimum transmission distance and the relative pseudorange;

The positioning algorithm is an iterative operation process, and uses the pseudo-range observation information to calculate the coordinate position of the receiving point; when calculating the subsequent pseudo-range observation, the number of milliseconds between the sub-frames of each observation satellite and reference satellite is maintained to ensure that each tracking channel is chipped The real moment of the rising edge;

Step S2.2: Obtain the Doppler frequency shift amount, that is, the Doppler frequency shift observation amount

The tracking processing process in the receiver terminal adaptive dynamic switching receiving processing system is to accurately calculate and capture the carrier frequency and code phase information of the GNSS satellite navigation signal transmitted by the observation satellite, and can stably and continuously synchronize the output result value that changes with the tracking processing time. The tracking accuracy is directly related to the pseudorange observation information; the obtained Doppler frequency shift observation is the difference between the carrier frequency of the tracking processing and the nominal carrier frequency of the satellite navigation signal. That is: Doppler frequency shift observation = tracking processing carrier frequency - signal nominal carrier frequency.

Example 5

A method for constructing a navigation signal receiving and processing based on adaptive dynamic switching according to Embodiment 3, the difference is:

The specific implementation process of step S3 is as follows:

Step S3.1: Calculate the position information data

Through the extracted navigation message data information, pseudo-range observation information and precise distance information data, the three-dimensional space position of the receiving solution point in the coordinate system is obtained:

The observation equation is shown in formula (VIII):

表示第i颗观测卫星大气延迟误差；In formula (VIII), ρ ⁱ represents the pseudo-range observation amount of the i-th observation satellite, (X _j , Y _j , Z _j ) represents the three-dimensional space position of the receiving point in the coordinate system, (X ⁱ , Y ⁱ , Z ⁱ ) represents the i-th observation satellite in a certain receiving scene area, dt represents the receiver terminal clock error, dT ⁱ represents the i-th observation satellite clock error,

represents the atmospheric delay error of the i-th observation satellite;

The coordinate position of the observation satellite, the satellite clock error, and the atmospheric delay error are obtained from the navigation message data information, and the full rank condition of the observation equation (VIII) is satisfied. Obtain the position information data (X _j , Y _j , Z _j ) of the received solution point and the receiver terminal clock error.

Step S3.2: Calculation of motion speed information data

Through the extracted navigation text data information and tracking processing data, the movement speed of the receiving solution point in the coordinate system is obtained; the observation equation is shown in formula (IX):

D=e ⁱ (vi -v ^j )+b+δ _i ⁽ IX)

为第i颗观测卫星多普勒频移量，λ为接收GNSS卫星导航信号载波频率波长，vⁱ为第i颗观测卫星运动速度，由提取的导航电文数据获得，v_j为接收解算点运动速度信息数据，其对应坐标系下的3个方向运动速度分别为[v_xj,v_yj,v_zj]^T，eⁱ为接收解算点与观测卫星之间连线方向的余弦参数变量，其3个方向参数变量分别为：In formula (IX), D is the Doppler frequency shift,

is the Doppler frequency shift of the i-th observation satellite, λ is the carrier frequency wavelength of the received GNSS satellite navigation signal, v ⁱ is the motion speed of the i-th observation satellite, obtained from the extracted navigation message data, and v _j is the receiving solution point Movement velocity information data, the movement velocity in the corresponding three directions in the coordinate system is [v _xj , v _yj , v _zj ] ^T , e ⁱ is the cosine parameter variable of the connection direction between the receiving solution point and the observation satellite, Its three direction parameter variables are:

(X _j , Y _j , Z _j ) represents the three-dimensional space position of the receiving solution point in the coordinate system, (X ⁱ , Y ⁱ , Z ⁱ ) represents the i-th observation satellite in a certain receiving scene area, and b is the receiver The rate of change of the terminal clock error, δ ⁱ is the error term caused by various factors such as the observation satellite clock error, ionospheric error, and tropospheric error;

Satisfying the full rank condition of the observation equation (IX) means receiving and processing the GNSS satellite navigation signal data transmitted by 4 or more observation satellites, and obtaining the motion speed information data of the receiving and solving point by solving the equation (I).

Claims (6)

1. a navigation signal receiving and processing system based on adaptive dynamic switching, is characterized in that, comprising: receiver terminal adaptive dynamic switching receiving processing system, receiver pseudorange solution system, receiver position data processing system, information transmission system system and information data storage system; Wherein, the receiver terminal adaptive dynamic switching reception processing system uses overhead visible satellites, selects landmark points as receiving and solving points, and receives, processes, and navigates the multi-mode and multi-frequency GNSS satellite navigation signals transmitted by overhead visible satellites. Extraction of telegram data, baseband calculation, and acquisition of visual receiving satellite information data at the receiving and solving point; The receiver pseudo-range calculation system performs information data calculation and extraction on the pseudo-range information of the receiving and solving point and the overhead visible satellite, and obtains the precise distance information data between each visible receiving satellite and the receiving and calculating point. ; Calculate and extract the Doppler frequency shift amount of the tracking processing of the receiver terminal adaptive dynamic switching receiving processing system; The receiver position data processing system aggregates the navigation message data information provided by the receiver terminal adaptive dynamic switching reception processing system, and simultaneously aggregates the precise distance information data and Doppler frequency shift information data provided by the receiver pseudorange solution system. , obtain the characteristic matrix of position solution and motion speed solution, and obtain the precise coordinate position information data and motion speed information data of the received solution point by solution; The information transmission system sends to the information data storage system the precise coordinate position information data of the received solution point and the movement speed information data obtained by the solution; The information data storage system organizes and archives the precise coordinate position information data of the receiving and solving point and the moving speed information data transmitted by the information transmission system, and constructs a large database of the receiving and solving point position and moving speed information. 2. a navigation signal receiving and processing construction method based on adaptive dynamic switching, the navigation signal receiving and processing system according to claim 1 receives overhead visible satellite transmission GNSS signal, it is characterized in that, comprises the steps: Step S1, select the object point as the receiving and solving point, perform receiving processing, navigation message data extraction, baseband solving on the multi-mode and multi-frequency GNSS satellite navigation signals transmitted by the overhead visible satellite, and obtain the receiving and solving point visual receiving satellite. information data; Step S2, solve and extract the pseudo-range information data between the receiving and solving point and the overhead visible satellite, and obtain the precise distance information data between each visible receiving satellite and the receiving and solving point; Adapt to the Doppler frequency shift in the tracking process of the dynamic switching receiving and processing system; In step S3, the extracted navigation text data information, Doppler frequency shift amount and precise distance information data are unifiedly aggregated to obtain the characteristic matrix of position solution and motion speed solution, and the precise coordinate position information data of the receiving and solution point are obtained through calculation, Movement speed information data; Step S4, sending the precise coordinate position information data and motion speed information data of the received solution point obtained by the solution to the back-end information data storage system; In step S5, the back-end information data storage system uniformly aggregates and transmits the precise coordinate position information data and motion speed information data, and archives them according to an effective database data management method, and constructs a large database of receiving and solving point positions and motion speed information. 3. a kind of navigation signal receiving and processing construction method based on adaptive dynamic switching according to claim 2, is characterized in that, the concrete realization process of step S1 comprises: Step S1.1: Receive and process GNSS satellite navigation signals Receive the multi-mode and multi-frequency GNSS satellite navigation signal transmitted by the overhead visible satellite, and convert it into digital signal data after digital frequency conversion, sampling and quantization; Step S1.2: Acquire tracking processing data The receiving and solving point is based on the real-time acquisition of the moving speed information data of the receiving and solving point, and the adaptive and dynamic switching tracking loop solution method is used to track the GNSS satellite navigation signal with high precision and accuracy; The movement speed information data refers to the real-time movement speed of the carrier when the receiver terminal adaptive dynamic switching receiving processing system receives the GNSS satellite navigation signal; in the static state, the true value of the movement speed of the receiving solution point is 0; Use the Doppler frequency shift in the tracking process for motion velocity measurement and calculation to obtain motion velocity information data; the solution equation is shown in formula (I): λD _i =ρ _i +c·dt _u -c·dt _i -I _i +T _i +ε (I) In formula (I), λ is the carrier frequency wavelength, D _i is the observed value of the Doppler frequency shift of the i-th observation satellite, ρ _i is the rate of change of the pseudo-range observation, c is the speed of light, and dt _u and dt _i are the receiving The rate of change of the clock error of the terminal and the rate of change of the clock error of the i-th observation satellite, I _i and T _i are the rate of change of the ionosphere and troposphere delays, respectively, and ε is the observation noise; The direction cosine (e ^xi _i , e ^yi , e ^zi ) between the receiving and solving point (X _u , _Yu , Z _u ) and the observation satellite (X _i , Y _i , Z _i ) is shown in formula (II), formula (III), shown in formula (IV):

The rate of change of pseudorange observations is shown in formula (V):

In formula (V),

is the running speed of the i-th observation satellite,

is the movement speed of the receiving solution point, [e ^xi e ^yi e ^zi ] is the cosine of the direction between the receiving solution point and the observation satellite i; The satellite position and satellite running speed are calculated from the navigation message data information; the approximate coordinate position of the receiving and solving point is obtained, then the moving speed of the receiving and solving point and the rate of change of the receiver clock error are unknowns to be determined; when 4 or more observation satellites are received, Construct a system of characteristic matrix equations, and solve the unknowns to be solved by the least squares method; Step S1.3: Extract navigation message data through signal capture and tracking processing After the satellite navigation signal tracking process is completed, the real-time I branch component information obtained by the tracking loop demodulation is subjected to bit synchronization, frame synchronization, and parity check processing procedures, and the navigation message data is extracted bit by bit. 4. a kind of navigation signal receiving and processing construction method based on adaptive dynamic switching according to claim 3, is characterized in that, the concrete realization process of step S1.2 comprises: When the motion acceleration of the receiving and solving point is less than 5gm/s ² and the speed is less than 25m/s, the receiving and solving point adopts the tracking loop structure of the second-order frequency-locked loop assisted by the third-order phase-locked loop to receive and process the GNSS satellite navigation signal; When the motion acceleration of the receiving and solving point is greater than 5gm/s ² and the speed is greater than 25m/s, the receiving and solving point adopts the extended Kalman filter tracking loop structure to receive and process the GNSS satellite navigation signal. 5. a kind of navigation signal receiving and processing construction method based on adaptive dynamic handover according to claim 2, is characterized in that, the concrete realization process of step S2 comprises: Step S2.1: Acquire pseudorange information data, that is, pseudorange observation quantity information The pseudo-range observation information is obtained by using code correlation technology, and a local replica code with the same structure as the observation satellite ranging code is generated; the receiving and solving point is divided into multiple satellite navigation signal receiving channels, and each satellite navigation signal receiving channel continuously tracks a separate Satellite navigation signals, maintain stable and continuous tracking of satellite navigation signals; use the tracking results and frame synchronization header position information to obtain pseudo-range observation information by relative measurement: 1) Taking the observation satellite closest to the receiving and solving point as the reference satellite, and taking the position moment of the rising edge of the frame synchronization header as the moment of obtaining the pseudo-range observation quantity information of each observation satellite; 2) Calculate the relative pseudorange Δρ _i between each observation satellite and the reference satellite, as shown in formula (VI):

In formula (VI),

is the position moment of the rising edge of the frame synchronization header of the i-th observation satellite; 3) Observing satellite pseudo-range observation quantity information ρ _i , as shown in formula (VII):

In formula (VII), dt is the satellite clock error parameter,

In order to receive the minimum transmission time of the built-in GNSS satellite navigation signal at the calculation point, the minimum transmission distance of the satellite navigation signal is multiplied by the speed of light c, and the pseudorange observation information of each observation satellite is the accumulation of the minimum transmission distance and the relative pseudorange; Step S2.2: Obtain the Doppler frequency shift amount, that is, the Doppler frequency shift observation amount The obtained Doppler frequency shift observation is the difference between the tracked carrier frequency and the nominal carrier frequency of the satellite navigation signal. 6. a kind of navigation signal receiving and processing construction method based on adaptive dynamic switching according to any one of claims 2-5, it is characterized in that, the concrete realization process of step S3 is as follows: Step S3.1: Calculate the position information data Through the extracted navigation message data information, pseudo-range observation information and precise distance information data, the three-dimensional space position of the receiving solution point in the coordinate system is obtained: The observation equation is shown in formula (VIII):

In formula (VIII), ρ ⁱ represents the pseudo-range observation amount of the i-th observation satellite, (X _j , Y _j , Z _j ) represents the three-dimensional space position of the receiving point in the coordinate system, (X ⁱ , Y ⁱ , Z ⁱ ) represents the ith observation satellite, dt represents the receiver terminal clock error, dT ⁱ represents the ith observation satellite clock error,

represents the atmospheric delay error of the i-th observation satellite; The coordinate position of the observation satellite, the satellite clock error, and the atmospheric delay error are obtained from the navigation message data information, and the full rank condition of the observation equation (VIII) is satisfied. Acquire the position information data (X _j , Y _j , Z _j ) of the receiving and resolving point and the receiver terminal clock difference; Step S3.2: Calculation of motion speed information data Through the extracted navigation message data information and tracking processing data, the movement speed of the receiving and solving point in the coordinate system is obtained; The observation equation is shown in formula (IX): D=e ⁱ (vi -v ^j )+b+δ _i ⁽ IX) In formula (IX), D is the Doppler frequency shift,

is the Doppler frequency shift of the i-th observation satellite, λ is the carrier frequency wavelength of the received GNSS satellite navigation signal, v ⁱ is the motion speed of the i-th observation satellite, obtained from the extracted navigation message data, and v _j is the receiving solution point Movement velocity information data, the movement velocity in the corresponding three directions in the coordinate system is [v _xj , v _yj , v _zj ] ^T , e ⁱ is the cosine parameter variable of the connection direction between the receiving solution point and the observation satellite, Its three direction parameter variables are:

(X _j , Y _j , Z _j ) represents the three-dimensional space position of the receiving solution point in the coordinate system, (X ⁱ , Y ⁱ , Z ⁱ ) represents the i-th observation satellite, and b is the receiver terminal clock error rate of change , δ ⁱ is the error term caused by various factors including observation satellite clock error, ionospheric error and tropospheric error; Satisfying the full rank condition of the observation equation (IX) means receiving and processing the GNSS satellite navigation signal data transmitted by 4 or more observation satellites, and obtaining the motion speed information data of the receiving and solving point by solving the equation (I).

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