A relative time synchronization method, device and medium based on dynamic-to-dynamic

Abstract

The present invention provides a dynamic-to-dynamic relative time synchronization method, device and medium, which relate to the field of satellite navigation timing technology, and include the following steps: S1, a mobile station receiver obtains differential data sent by a reference station; S2, the mobile station receiver uses its own epoch time as the reference moment to calculate observation quantities and correct clock errors; S3, the mobile station constructs a double-difference observation quantity based on a first pseudorange observation quantity and a second pseudorange observation quantity and performs Kalman filtering to obtain the position coordinates of the current mobile station relative to the reference station; S4, the mobile station determines the signal transmission time correction value of each satellite frequency point by aligning the first corrected epoch time and the second corrected epoch time, calculates the clock deviation of the current mobile station relative to the reference station based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time and the second signal transmission time, and adjusts the clock of the current mobile station receiver according to the clock deviation.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite navigation timing, and in particular to a relative time synchronization method, device and medium based on dynamic-to-dynamic synchronization. Background Art

[0002] With the continuous development of information technology fields such as national defense, communications systems, and unmanned driving, the demand for time accuracy is becoming increasingly stringent. High-precision time synchronization technology has become a key national strategic development requirement. Global Navigation Satellite System (GNSS)-based timing technology offers advantages such as high-precision time synchronization, high stability, and consistent multi-node time performance, making it one of the most widely used timing methods.

[0003] For some specific scenarios, such as dynamic-to-dynamic multi-target collaboration, higher timing accuracy and synchronization stability are often required compared to conventional absolute and relative positioning. Therefore, the present invention proposes a timing method that can meet absolute timing accuracy and relative time synchronization accuracy. Summary of the Invention

[0004] The purpose of the present invention is to provide a relative time synchronization method, device and medium based on dynamic-to-dynamic. The method mainly sends the signal transmission time, corrected epoch time and pseudo-range observation value obtained by the base station receiver as differential data to the mobile station. The mobile station can calculate the clock deviation of the current mobile station relative to the base station through the epoch time difference and signal transmission time difference between itself and the base station. The present invention can meet the requirements of real-time high-precision timing and time synchronization under dynamic-to-dynamic multi-target coordination, and can also achieve relative positioning.

[0005] In order to solve the above technical problems, the present invention adopts the following solutions:

[0006] A relative time synchronization method based on dynamic-to-dynamic synchronization comprises the following steps:

[0007] S1. The mobile station receiver obtains differential data sent by the reference station, wherein the differential data includes the first signal transmission time of each satellite frequency point, the first pseudorange observation value, and the first corrected epoch time obtained after the reference station receiver performs observation calculation and clock correction based on its own epoch time as the reference time;

[0008] S2. The mobile station receiver uses its own epoch time as the reference time to perform observation calculation and clock error correction, and obtains the second signal transmission time of each satellite frequency point, the second pseudorange observation value, and the second corrected epoch time;

[0009] S3. The mobile station constructs a double-difference observation value based on the first pseudorange observation value and the second pseudorange observation value and performs a Kalman filter solution to obtain the current position coordinates of the mobile station relative to the reference station;

[0010] S4. The mobile station determines the signal transmission time correction value of each satellite frequency point by aligning the first corrected epoch time and the second corrected epoch time, calculates the clock deviation of the current mobile station relative to the reference station based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time, and the second signal transmission time, and adjusts the clock of the current mobile station receiver according to the clock deviation.

[0011] Furthermore, in S1, the process of calculating the observation amount and correcting the clock error by the base station receiver using its own epoch time as the reference time includes the following steps:

[0012] SA1: The base station receiver uses its own epoch time as the reference time to calculate the first pseudorange observation value of each satellite frequency point by obtaining the first signal transmission time of each satellite frequency point;

[0013] SA2: Obtain the satellite position and satellite clock error calculated using the B1C and L1I broadcast ephemeris, and correct the satellite position and satellite clock error according to the B2b message to obtain the corrected satellite position and satellite clock error.

[0014] SA3. Establish a pseudorange observation equation based on the first pseudorange observation value, the corrected satellite position, and the satellite clock error, and perform a least squares solution on the equation to obtain a first receiver clock error.

[0015] SA4. Perform clock error correction on the local epoch time according to the first receiver clock error to obtain a first corrected epoch time.

[0016] Furthermore, step S2 includes the following steps:

[0017] S21. The mobile station receiver calculates a second pseudorange observation value of each satellite frequency point by using its own epoch time as a reference time and obtaining the second signal transmission time of each satellite frequency point;

[0018] S22. Obtain the satellite position and satellite clock error calculated using the B1C and L1I broadcast ephemeris, and correct the satellite position and satellite clock error according to the B2b message to obtain the corrected satellite position and satellite clock error;

[0019] S23, establishing a pseudorange observation equation based on the second pseudorange observation value, the corrected satellite position and the satellite clock error, and performing a least squares solution on the pseudorange observation equation to obtain a second receiver clock error;

[0020] S24. Correct the clock error of the local epoch time according to the second receiver clock error to obtain a second corrected epoch time.

[0021] Furthermore, the B2b message includes an orbit correction number and a clock correction number. The satellite position is corrected according to the orbit correction number in the B2b message to obtain a corrected satellite position; the satellite clock error is corrected according to the clock correction number in the B2b message to obtain a corrected satellite clock error.

[0022] Furthermore, the S4 includes the following steps:

[0023] S41. Aligning the first corrected epoch time with the second corrected epoch time to obtain an epoch time difference between the first corrected epoch time and the second corrected epoch time, and calculating the Doppler shift of each satellite frequency point based on the epoch time difference to obtain a signal transmission time correction value for each satellite frequency point;

[0024] S42: Calculate the clock difference based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time, and the second signal transmission time to obtain the clock deviation of the current mobile station relative to the reference station.

[0025] Furthermore, the step S42 includes the following steps:

[0026] S421. Calculate the difference in signal transmission time of each satellite frequency point between the mobile station and the reference station based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time, and the second signal transmission time;

[0027] S422. Calculate a receiver clock difference between the mobile station and the reference station based on the signal transmission time difference of each satellite frequency point, the first receiver clock difference, and the second receiver clock difference;

[0028] S423: Calculate an average value based on the receiver clock differences between the mobile station and the reference station, and use the average value as the clock deviation of the current mobile station relative to the reference station.

[0029] Furthermore, in S4, the process of adjusting the clock of the current mobile station receiver according to the clock deviation is as follows:

[0030] By calibrating the current mobile station receiver in advance, the constant deviation of the current mobile station receiver can be obtained. The difference between the constant deviation and the clock deviation of the current mobile station relative to the reference station is calculated, and the clock of the current mobile station receiver is adjusted based on the difference.

[0031] A relative time synchronization device based on dynamic-to-dynamic synchronization, comprising:

[0032] a memory for non-transitory storage of computer-readable instructions;

[0033] The processor is used to execute the computer-readable instructions, and the computer-readable instructions, when executed by the processor, implement the dynamic-to-dynamic relative time synchronization method.

[0034] A non-transitory computer-readable storage medium stores computer-readable instructions, wherein the computer-readable instructions, when executed by a processor, implement the dynamic-to-dynamic relative time synchronization method.

[0035] Beneficial effects of the present invention:

[0036] The present invention provides a relative time synchronization method, device and medium based on dynamic-to-dynamic synchronization. The method mainly uses the current epoch time as the reference time to obtain the signal transmission time of the GPS / BDS satellite frequency point, the corrected epoch time and the pseudo-range observation value of the base station receiver, and sends them to the mobile station as differential data. The mobile station can calculate the clock deviation of the current mobile station relative to the base station through the epoch time difference and the signal transmission time difference between itself and the base station. Therefore, the present invention can meet the requirements of real-time high-precision timing and time synchronization under dynamic-to-dynamic multi-target coordination, and can also achieve relative positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the steps of a dynamic-to-dynamic relative time synchronization method in Example 1 of the present invention;

[0038] Figure 2 This is a flow chart of a dynamic-to-dynamic relative time synchronization method in Example 1 of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Unless otherwise specifically stated, the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0041] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0042] Additionally, descriptions of well-known structures, functions, and configurations may be omitted for clarity and conciseness. Those skilled in the art will recognize that various changes and modifications can be made to the examples described herein without departing from the spirit and scope of the present disclosure.

[0043] Technologies, methods and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods and equipment should be considered part of the authorization specification.

[0044] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0045] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments:

[0046] Example 1

[0047] In this embodiment, if Figure 1 As shown, a relative time synchronization method based on dynamic to dynamic is proposed, and the method includes the following steps:

[0048] S1. The mobile station receiver obtains differential data sent by the reference station, wherein the differential data includes the first signal transmission time of each satellite frequency point, the first pseudorange observation value, and the first corrected epoch time obtained after the reference station receiver performs observation calculation and clock correction based on its own epoch time as the reference time;

[0049] S2. The mobile station receiver uses its own epoch time as the reference time to perform observation calculation and clock error correction, and obtains the second signal transmission time of each satellite frequency point, the second pseudorange observation value, and the second corrected epoch time;

[0050] S3. The mobile station constructs a double-difference observation value based on the first pseudorange observation value and the second pseudorange observation value and performs a Kalman filter solution to obtain the current position coordinates of the mobile station relative to the reference station;

[0051] S4. The mobile station determines the signal transmission time correction value of each satellite frequency point by aligning the first corrected epoch time and the second corrected epoch time, calculates the clock deviation of the current mobile station relative to the reference station based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time, and the second signal transmission time, and adjusts the clock of the current mobile station receiver according to the clock deviation.

[0052] Preferably, in S1, the process of calculating the observation amount and correcting the clock error by the reference station receiver using its own epoch time as the reference time includes the following steps:

[0053] SA1: The base station receiver uses its own epoch time as the reference time to calculate the first pseudorange observation value of each satellite frequency point by obtaining the first signal transmission time of each satellite frequency point;

[0054] SA2: Obtain the satellite position and satellite clock error calculated using the B1C and L1I broadcast ephemeris, and correct the satellite position and satellite clock error according to the B2b message to obtain the corrected satellite position and satellite clock error.

[0055] SA3. Establish a pseudorange observation equation based on the first pseudorange observation value, the corrected satellite position, and the satellite clock error, and perform a least squares solution on the equation to obtain a first receiver clock error.

[0056] SA4. Perform clock error correction on the local epoch time according to the first receiver clock error to obtain a first corrected epoch time.

[0057] Preferably, the step S2 includes the following steps:

[0058] S21. The mobile station receiver calculates a second pseudorange observation value of each satellite frequency point by using its own epoch time as a reference time and obtaining the second signal transmission time of each satellite frequency point;

[0059] S22. Obtain the satellite position and satellite clock error calculated using the B1C and L1I broadcast ephemeris, and correct the satellite position and satellite clock error according to the B2b message to obtain the corrected satellite position and satellite clock error;

[0060] S23, establishing a pseudorange observation equation based on the second pseudorange observation value, the corrected satellite position and the satellite clock error, and performing a least squares solution on the pseudorange observation equation to obtain a second receiver clock error;

[0061] S24. Correct the clock error of the local epoch time according to the second receiver clock error to obtain a second corrected epoch time.

[0062] Preferably, the B2b message includes an orbit correction number and a clock correction number. The satellite position is corrected according to the orbit correction number in the B2b message to obtain a corrected satellite position; the satellite clock error is corrected according to the clock correction number in the B2b message to obtain a corrected satellite clock error.

[0063] Preferably, said S4 includes the following steps:

[0064] S41. Aligning the first corrected epoch time with the second corrected epoch time to obtain an epoch time difference between the first corrected epoch time and the second corrected epoch time, and calculating the Doppler shift of each satellite frequency point based on the epoch time difference to obtain a signal transmission time correction value for each satellite frequency point;

[0065] S42: Calculate the clock difference based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time, and the second signal transmission time to obtain the clock deviation of the current mobile station relative to the reference station.

[0066] Preferably, the step S42 includes the following steps:

[0067] S421. Calculate the difference in signal transmission time of each satellite frequency point between the mobile station and the reference station based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time, and the second signal transmission time;

[0068] S422. Calculate a receiver clock difference between the mobile station and the reference station based on the signal transmission time difference of each satellite frequency point, the first receiver clock difference, and the second receiver clock difference;

[0069] S423: Calculate an average value based on the receiver clock differences between the mobile station and the reference station, and use the average value as the clock deviation of the current mobile station relative to the reference station.

[0070] Preferably, in S4, the process of adjusting the clock of the current mobile station receiver according to the clock deviation is:

[0071] By calibrating the current mobile station receiver in advance, the constant deviation of the current mobile station receiver can be obtained. The difference between the constant deviation and the clock deviation of the current mobile station relative to the reference station is calculated, and the clock of the current mobile station receiver is adjusted based on the difference.

[0072] Based on the above principles, the present invention is further elaborated:

[0073] In this embodiment, the dynamic-to-dynamic refers to the base station to the mobile station. In order to achieve real-time high-precision relative positioning and time synchronization between the base station and the mobile station, a relative time synchronization method based on dynamic-to-dynamic is proposed, which is mainly used to calculate the clock deviation of the mobile station relative to the base station. Therefore, the clock of the current mobile station receiver can be adjusted in real time through the clock deviation.

[0074] Before calculating the clock deviation of the mobile station relative to the reference station, the signal transmission time, corrected epoch time and pseudo-range observation value obtained by the reference station receiver must first be sent to the mobile station as differential data. The mobile station can then calculate the clock deviation of the current mobile station relative to the reference station through the epoch time difference and signal transmission time difference between itself and the reference station. Both the reference station and the mobile station need to use the current epoch time as the reference time to perform observation calculation and clock deviation correction to obtain the corresponding signal transmission time, corrected epoch time and pseudo-range observation value. Since the reference station and the mobile station have their own clocks, The current epoch time under their respective clocks is different. The base station and the mobile station use the current epoch time of their own clocks as the reference time, that is, use their own historical time as the reference time, so that the base station and the mobile station obtain the signal transmission time of each satellite frequency point of the GPS / BDS satellite system based on their own historical time, calculate the pseudo-range observation amount according to the signal transmission time of each satellite frequency point, and use the B2b telegram correction information to correct the satellite position and satellite clock error. Then, perform conventional single-point positioning solution to obtain the corresponding receiver clock error in the GPS / BDS satellite system, and then correct their own epoch time.

[0075] According to the above-mentioned relative time synchronization method based on dynamic to dynamic, combined with Figure 2 The actual operation process of this method is described in detail as follows:

[0076] Step 1-1: The base station receiver uses the current epoch time EpochTime as the reference time and calculates the pseudorange observation value of each satellite frequency point at the current reference time by obtaining the signal transmission time Ts of each GPS / BDS satellite signal frequency point. The calculation method is as follows:

[0077]

[0078] Where P represents the calculated pseudorange observation, EpochTime is the epoch time, Ts is the signal transmission time, c represents the speed of light, the superscript s represents the satellite number, and the subscripts k and fre represent an epoch and satellite frequency, respectively. The satellite frequencies represented by fre include B1I, B3I, B1C, L1I, and L2C.

[0079] Step 1-2: Correct the satellite positions and satellite clock errors calculated using the B1C and L1I broadcast ephemeris according to the B2b message, i.e., make orbit and clock corrections. The B2b message is used to correct the CNAV1 message of the BDS and the LNAV navigation message of the GPS. Therefore, for the satellite positions and satellite clock errors calculated using the B1C and L1I broadcast ephemeris, the orbit and clock corrections in the B2b message are used to correct them, while the others are not corrected:

[0080] The orbit correction is calculated as follows:

[0081] X orbit =X broadcast -δX;

[0082] Among them, X orbit is the corrected satellite position, X broadcast is the satellite position calculated by broadcast ephemeris, and δX is the orbit correction number;

[0083] The orbit correction number δX is calculated as follows:

[0084]

[0085]

[0086] e along =e cross ×e radial ;

[0087] δX=[e radial e along e cross ]·δο;

[0088] Where r represents the broadcast ephemeris satellite position vector, represents the broadcast ephemeris satellite velocity vector, e i is the direction unit vector, i = {radial, along, cross} corresponds to radial, tangential, and normal directions respectively; δο is the orbit correction vector in the three directions in the B2b message;

[0089] The calculation method of the clock error correction is:

[0090]

[0091] Among them, t satellite is the corrected satellite clock error, t broadcast is the satellite clock error calculated from the broadcast ephemeris, c is the speed of light, and C0 is the clock error correction number in the B2b message.

[0092] Step 1-3: Establish a pseudorange residual model based on the pseudorange observation equation, perform conventional least squares calculations, and solve for the receiver clock error. The specific process is as follows:

[0093]

[0094] Among them, Z is the pseudorange residual, P is the pseudorange observation, r is the satellite-to-ground distance, δt u and δt srepresent the receiver clock error and satellite clock error respectively, Iono and Trop are ionospheric delay and trajectory delay respectively;

[0095] The covariance matrix R is constructed as follows:

[0096] R i =sqrt(fact 2 *(a 2 +a 2 / (sin(e)))*3 2 +vtrop+vari+vare+var orbit +var clk );

[0097] Among them, vtrop is the tropospheric error term, vari is the ionospheric error term, vare is the clock error term, and var orbit is the orbit correction error term, var clk is the satellite clock correction error term, fact and a are empirical constants, and e is the satellite elevation angle;

[0098] The geometry matrix H is:

[0099]

[0100] Among them, the direction vector I xyz For: I xyz =[e x e y e z 1] T ;

[0101] Then the least squares equation is solved as follows:

[0102] Δx=((H / R)′*(H / R)) -1 *(H / R)'*(Z / R);

[0103] Where: Δx=[xyz clk gps clk bds ], where x, y, z are position parameters, clk gps ,clk bds are the GPS and BDS receiver clock error parameters respectively.

[0104] Step 1-4: Correct the current epoch time based on the calculated receiver clock error. The calculation method is as follows:

[0105]

[0106] Step 1-5: Use the corrected EpochTime as the reference time for calculating the pseudorange observation value of the next epoch. The calculation formula is as follows:

[0107] Step 1-6: Use the corrected EpochTime as the observation time, and customize the signal transmission time Ts of each satellite frequency point according to the standard RTCM protocol format, and broadcast it as differential data via 4G.

[0108] Step 2: Follow steps 1-1 to 1-6 above to correct the observations of the mobile station and obtain the receiver clock error.

[0109] Step 3: Perform conventional Kalman filter solution, where the Kalman filter algorithm state equation and observation equation can be expressed as:

[0110]

[0111] Among them, X and Y are the state vector and observation vector respectively, V and W are the observation noise and process noise respectively, Φ is the state transfer matrix, Γ is the input relationship matrix, and H is the relationship matrix between the observation quantity and the system state.

[0112] Furthermore, in Kalman filtering, it is usually assumed that the observation noise V k and system process noise W k-1 are independent and uncorrelated with each other, and they all conform to the statistical characteristics of Gaussian white noise, which can be expressed as:

[0113]

[0114] Among them, R k is the covariance matrix of the observation noise, Q k is the covariance matrix of the system process noise, δ kj The matrix expression is:

[0115]

[0116] The Kalman filter recursive process is as follows:

[0117] (1) Calculate the predicted value of the state vector for epoch k:

[0118]

[0119] (2) Calculate the state mean square error matrix:

[0120]

[0121] (3) Calculate the Kalman filter gain:

[0122]

[0123] (4) Perform state estimation:

[0124]

[0125] (5) Calculate the estimated mean square error matrix:

[0126] P k =(IK k H k )P k,k-1 ;

[0127] Where, “^” represents the estimated value, I is the unit matrix, is the predicted value of the state vector, P k,k-1 is the corresponding state mean square error matrix, K k is the Kalman filter gain, is the filtered estimate, P k is the corresponding estimated mean square error matrix.

[0128] The optimal solution is obtained by the Kalman filter mentioned above, and the position coordinates of the receiver between the base station and the mobile station are obtained, which can achieve centimeter-level positioning accuracy.

[0129] Step 4-1: Calculate and obtain the epoch time difference between the first corrected epoch time and the corresponding second corrected epoch time, that is, calculate the epoch time difference EpochDiff between the mobile station and the reference station, as follows:

[0130]

[0131] Here, i represents the BDS and GPS satellite systems, the subscripts rover and base represent the rover station and the base station, respectively, and k is the epoch time.

[0132] Step 4-2: Select the B1I and L1I frequencies of the BDS and GPS satellite systems respectively, and calculate the time correction CorrTs using the Doppler shift:

[0133]

[0134] Where frq represents the B1I and L1I frequencies, and Doppler represents the Doppler shift in the observation value.

[0135] Step 4-3: After correcting the epoch time, you can start calculating the difference between the mobile station and the base station receiver clock. The process is as follows:

[0136] (1) Calculate the difference in Ts for each satellite between the mobile station and the base station:

[0137]

[0138] (2) Calculate the difference between the mobile station and the base station receiver clock errors based on the observation equation of each satellite:

[0139]

[0140] (3) The average value is the clock deviation of the mobile station relative to the reference station in this epoch:

[0141]

[0142] Step 4-3: Due to the delay between different hardware, there will be a constant deviation between the clock errors of the two receivers. Therefore, the device needs to be calibrated before use to solve for this constant deviation:

[0143] BiasClk k =(ClkDiff1′+ClkDiff2′+…+ClkDiff n ′) / n;

[0144] At this time, the deviation of the real receiver clock error of the mobile station relative to the reference station at each epoch is:

[0145] ClkDiff k = ClkDiff k ′-BiasClk k ;

[0146] Finally, the receiver clock is adjusted in real time according to the calculated deviation value.

[0147] Example 2

[0148] A relative time synchronization device based on dynamic-to-dynamic synchronization, comprising:

[0149] a memory for non-transitory storage of computer-readable instructions;

[0150] The processor is used to execute the computer-readable instructions, and the computer-readable instructions, when executed by the processor, implement the dynamic-to-dynamic relative time synchronization method.

[0151] A non-transitory computer-readable storage medium stores computer-readable instructions, wherein the computer-readable instructions, when executed by a processor, implement the dynamic-to-dynamic relative time synchronization method.

[0152] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Based on the technical essence of the present invention and within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement of the above embodiment shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A relative time synchronization method based on dynamic to dynamic, characterized in that: The method comprises the following steps: S1. The mobile station receiver obtains differential data sent by the reference station, wherein the differential data includes the first signal transmission time of each satellite frequency point, the first pseudorange observation value, and the first corrected epoch time obtained after the reference station receiver performs observation calculation and clock correction based on its own epoch time as the reference time; S2. The mobile station receiver uses its own epoch time as the reference time to perform observation calculation and clock error correction, and obtains the second signal transmission time of each satellite frequency point, the second pseudorange observation value, and the second corrected epoch time; S3. The mobile station constructs a double-difference observation value based on the first pseudorange observation value and the second pseudorange observation value and performs a Kalman filter solution to obtain the current position coordinates of the mobile station relative to the reference station; S4. The mobile station determines the signal transmission time correction value of each satellite frequency point by aligning the first corrected epoch time and the second corrected epoch time, calculates the clock deviation of the current mobile station relative to the reference station based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time, and the second signal transmission time, and adjusts the clock of the current mobile station receiver according to the clock deviation.

2. A dynamic-to-dynamic relative time synchronization method according to claim 1, characterized in that: In S1, the process of calculating observations and correcting clock errors by the base station receiver using its own epoch time as the reference moment includes the following steps: SA1: The base station receiver uses its own epoch time as the reference time to calculate the first pseudorange observation value of each satellite frequency point by obtaining the first signal transmission time of each satellite frequency point; SA2: Obtain the satellite position and satellite clock error calculated using the B1C and L1I broadcast ephemeris, and correct the satellite position and satellite clock error according to the B2b message to obtain the corrected satellite position and satellite clock error. SA3. Establish a pseudorange observation equation based on the first pseudorange observation value, the corrected satellite position, and the satellite clock error, and perform a least squares solution on the equation to obtain a first receiver clock error. SA4. Perform clock error correction on the local epoch time according to the first receiver clock error to obtain a first corrected epoch time.

3. The method of relative time synchronization based on dynamic to dynamic according to claim 1, characterized in that: The step S2 includes the following steps: S21. The mobile station receiver calculates a second pseudorange observation value of each satellite frequency point by using its own epoch time as a reference time and obtaining the second signal transmission time of each satellite frequency point; S22. Obtain the satellite position and satellite clock error calculated using the B1C and L1I broadcast ephemeris, and correct the satellite position and satellite clock error according to the B2b message to obtain the corrected satellite position and satellite clock error; S23, establishing a pseudorange observation equation based on the second pseudorange observation value, the corrected satellite position and the satellite clock error, and performing a least squares solution on the pseudorange observation equation to obtain a second receiver clock error; S24. Correct the clock error of the local epoch time according to the second receiver clock error to obtain a second corrected epoch time.

4. A dynamic-to-dynamic relative time synchronization method according to claim 2 or 3, characterized in that: The B2b message includes an orbit correction number and a clock correction number. The satellite position is corrected according to the orbit correction number in the B2b message to obtain a corrected satellite position. The satellite clock error is corrected according to the clock error correction number in the B2b message to obtain the corrected satellite clock error.

5. The method of relative time synchronization based on dynamic to dynamic according to claim 1, characterized in that: The S4 includes the following steps: S41. Aligning the first corrected epoch time with the second corrected epoch time to obtain an epoch time difference between the first corrected epoch time and the second corrected epoch time, and calculating the Doppler shift of each satellite frequency point based on the epoch time difference to obtain a signal transmission time correction value for each satellite frequency point; S42: Calculate the clock difference based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time, and the second signal transmission time to obtain the clock deviation of the current mobile station relative to the reference station.

6. The method of relative time synchronization based on dynamic to dynamic according to claim 5, characterized in that: The step S42 includes the following steps: S421. Calculate the difference in signal transmission time of each satellite frequency point between the mobile station and the reference station based on the signal transmission time correction value of each satellite frequency point, the first signal transmission time, and the second signal transmission time; S422. Calculate a receiver clock difference between the mobile station and the reference station based on the signal transmission time difference of each satellite frequency point, the first receiver clock difference, and the second receiver clock difference; S423: Calculate an average value based on the receiver clock differences between the mobile station and the reference station, and use the average value as the clock deviation of the current mobile station relative to the reference station.

7. The method of relative time synchronization based on dynamic to dynamic according to claim 1, characterized in that: In S4, the process of adjusting the clock of the current mobile station receiver according to the clock deviation is as follows: By calibrating the current mobile station receiver in advance, the constant deviation of the current mobile station receiver can be obtained. The difference between the constant deviation and the clock deviation of the current mobile station relative to the reference station is calculated, and the clock of the current mobile station receiver is adjusted based on the difference.

8. A relative time synchronization device based on dynamic to dynamic, characterized in that: include: a memory for non-transitory storage of computer-readable instructions; A processor is used to execute the computer-readable instructions, wherein the computer-readable instructions, when executed by the processor, implement the dynamic-to-dynamic relative time synchronization method according to any one of claims 1 to 7.

9. A non-transitory computer-readable storage medium, wherein: The non-transitory computer-readable storage medium stores computer-readable instructions, and when the computer-readable instructions are executed by a processor, the method for relative time synchronization based on dynamic-to-dynamic synchronization according to any one of claims 1 to 7 is implemented.

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