CN110780588A - Wide-area accurate time service WPT system and method - Google Patents
Wide-area accurate time service WPT system and method Download PDFInfo
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- CN110780588A CN110780588A CN201910982975.1A CN201910982975A CN110780588A CN 110780588 A CN110780588 A CN 110780588A CN 201910982975 A CN201910982975 A CN 201910982975A CN 110780588 A CN110780588 A CN 110780588A
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- G—PHYSICS
- G04—HOROLOGY
- G04R—RADIO-CONTROLLED TIME-PIECES
- G04R20/00—Setting the time according to the time information carried or implied by the radio signal
- G04R20/02—Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS
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- G—PHYSICS
- G04—HOROLOGY
- G04F—TIME-INTERVAL MEASURING
- G04F5/00—Apparatus for producing preselected time intervals for use as timing standards
- G04F5/14—Apparatus for producing preselected time intervals for use as timing standards using atomic clocks
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- G—PHYSICS
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- G04R—RADIO-CONTROLLED TIME-PIECES
- G04R20/00—Setting the time according to the time information carried or implied by the radio signal
- G04R20/02—Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS
- G04R20/04—Tuning or receiving; Circuits therefor
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Abstract
The invention discloses a wide-area accurate time service system, called WPT system for short, which comprises a high-precision time product service platform, a time transmission system and a time synchronization receiver. The method comprises the steps that a synchronous receiver firstly obtains pseudo-range data, broadcast ephemeris and other public satellite signals through a GNSS antenna, meanwhile, a time reference refined data product from a high-precision time product service platform is received through a time transmission system, a local clock of the synchronous receiver is corrected through the time transmission system, the local clock and a satellite-borne clock are kept in accurate synchronization, calibrated signals such as 1PPS are obtained, and finally the signals are output to an application party. The invention can quickly trace the source to UTC, Beidou time and the like, and provides time service with a wide area range superior to 1 ns.
Description
Technical Field
The invention belongs to the field of Wide-area Precise Timing (WPT), and particularly relates to a WPT system and a WPT method.
Background
In a precise time service mode of a satellite navigation system, along with the improvement of precision and timeliness of IGS precise ephemeris and clock error products, an All-in-view (All-in-view) method becomes a precise time-frequency transmission technology superior to a CV method and becomes an important means for calculating the international atomic Time (TAI). Compared with the CV method, the AV method can improve a time transmission path, increase a large amount of data with a high elevation angle, and further improve the stability, reliability and completeness of time transmission. When the AV method introduces the observed value of the carrier phase, the method is called a PPP time transfer method. Diego et al have studied the time transfer performance of PPP using IGS final precision satellite clock error and orbit products, and have found that static PPP can achieve a time transfer accuracy of 0.1ns by comparison with a two-way satellite time-frequency comparison method (TWSTFT). In addition, the measurement noise of PPP time transfer is 1.5 times lower than that of TWSTFT in a short time (1 day), and the method is the method with the highest precision in the current GNSS time-frequency transfer technology.
In recent years, GNSS products provided by IGS data analysis centers lay the foundation for GNSS time transfer. On one hand, the GNSS product provides great convenience for eliminating satellite clock error, satellite orbit error and other modeling errors in PPP time transfer. At present, the track precision of an ultrafast precise ephemeris (IGU) provided by an IGS is about 5cm, and the precision of a satellite clock error is about 1.5 ns-3 ns; the accuracy of the fast/final ephemeris orbit is about 2.5cm and the accuracy of the satellite clock error is about 20 ps. On the other hand, in order to improve the time reference performance referred by the satellite clock error product, the external hydrogen clock tracking station is adopted to refine the reference in a post-processing mode, so that the situation that the IGS clock error reference jumps across the day is effectively improved. The daily stability of IGST is better than 1 × 10
-15Much higher than daily stability of 2X 10
-14GPST of (2).
The main problems of the existing PPP technology are that data products need post-processing and the instantaneity is poor. Because the IGS precision product has certain time ductility (the time delay of a quick product is 17-40 hours, and the time delay of a final product is about one week), the requirement of real-time precision time transfer cannot be met. On the other hand, the international high-precision time transmission technology mainly adopts GPS, and a Beidou-based wide-area real-time transmission technology system is not established.
Disclosure of Invention
Therefore, the invention provides a WPT system and a WPT method based on GNSS carrier observed quantity and state space domain correction, which can quickly trace the source to UTC, Beidou and the like and provide time service with a wide area range better than 1 ns.
The invention provides a WPT system, which comprises a high-precision time product service platform, a time transmission system and a time synchronization receiver,
the high-precision time product service platform comprises:
the system comprises a reference station data stream management unit, a global reference station data stream processing unit and a global reference station data stream processing unit, wherein the reference station data stream management unit is used for receiving and preprocessing global reference station data streams in real time;
the satellite orbit real-time determining unit is used for accessing an IGS tracking station observation data stream in the preprocessed global reference station data stream in real time and calculating a satellite orbit in real time;
the satellite clock error real-time estimation unit is used for accessing the IGS observation station observation data and the broadcast ephemeris in the preprocessed global reference station data stream in real time and estimating the satellite clock error in real time;
the clock error reference refinement unit is used for refining the reference of the satellite clock error estimated in real time by adopting a time reference refinement method to obtain a real-time precise satellite clock error product, and simultaneously, introducing UTC (k) time reference and reference comparison of the refined satellite clock error to ensure the safety and reliability of the obtained real-time precise satellite clock error product;
the troposphere delay modeling unit is used for processing the wet delay of the troposphere based on the zenith of the reference station and generating a troposphere delay product;
the satellite end FCB calculation unit is used for estimating a satellite end UPD based on the three-frequency observation value to obtain a satellite end FCB product;
the time transfer system includes:
the modeling error correction processing unit is used for performing modeling error correction processing on the obtained observation data in the GNSS signal accessed by the time synchronization receiver;
the differential correction decoding processing unit is used for carrying out differential correction decoding processing on the acquired real-time precise satellite clock error product, troposphere delay product and satellite end FCB product;
the receiver local clock error parameter estimation unit is used for carrying out combined processing on the processed observation data and the processed real-time precise satellite clock error product in wide-area precise time service to estimate the receiver clock error parameter; or accurately time-giving at a short baseline, and carrying out combined processing on the processed observation data, the processed real-time precise satellite clock error product, the troposphere delay product and the satellite-side FCB product to estimate local clock error parameters of the receiver;
the time synchronization receiver comprises a local clock and a clock regulation and control module, wherein the clock regulation and control module is used for processing the acquired local clock difference parameter of the receiver to form a regulation and control quantity by utilizing a crystal oscillator precision regulation and control technology and an atomic clock taming and punctuality technology, and correcting the local clock in real time to realize a time synchronization terminal.
In some embodiments, the time synchronization receiver may further include an antenna, a radio frequency front end module, and a baseband processing module, where the antenna is configured to access a GNSS signal, the radio frequency front end module is configured to perform down-conversion and filtering processing on the accessed GNSS signal, and the baseband processing module is configured to capture and track the down-converted and filtered GNSS signal, extract ephemeris, pseudorange, and carrier phase observation data therefrom, and send the extracted ephemeris, pseudorange, and carrier phase observation data to a modeling error correction processing unit of the time transfer system for modeling error correction processing.
The invention also provides a WPT method, which comprises the following processes:
s1: a time reference refinement data product acquisition process, said time reference refinement data product comprising a real-time precision satellite clock error product, a tropospheric delay product and a satellite-side FCB product, said acquisition process comprising the sub-processes of:
s11: receiving and preprocessing a global reference station data stream in real time;
s12: accessing an IGS tracking station observation data stream in the preprocessed global reference station data stream in real time, and calculating a satellite orbit in real time;
s13: accessing IGS observation station observation data and broadcast ephemeris in the preprocessed global reference station data stream in real time, and estimating satellite clock error in real time;
s14: the method comprises the steps of adopting a time reference refinement method to refine the reference of the satellite clock error estimated in real time to obtain a real-time precise satellite clock error product, simultaneously introducing UTC (k) time reference, and comparing the UTC (k) time reference with the reference of the refined satellite clock error to ensure the safety and reliability of the obtained real-time precise satellite clock error product;
s15: generating a tropospheric delay product based on the reference station zenith tropospheric wet delay;
s16: estimating a satellite end UPD based on the three-frequency observation value to obtain a satellite end FCB product;
s2 a time transfer process for transferring the acquired time reference refined data product to a time synchronization receiver via the internet, comprising the sub-steps of:
s21: acquiring observation data in GNSS signals accessed by a time synchronization receiver in real time and carrying out modeling error correction processing on the observation data;
s22: carrying out differential correction decoding processing on the acquired real-time precise satellite clock error product, troposphere delay product and satellite end FCB product;
s23: for wide-area accurate time service, combining the observation data processed in the step S21 with the real-time accurate satellite clock error product processed in the step S22, and estimating a receiver clock error parameter; for short-baseline accurate time service, combining the observation data processed in the step S21 with the real-time accurate satellite clock error product, the troposphere delay product and the satellite-side FCB product processed in the step S22, and estimating local clock error parameters of the receiver;
s3: the real-time correction process of the local clock comprises the following sub-steps:
s31: acquiring a local clock error parameter of a receiver;
s32: and (4) processing the local clock difference parameter of the receiver acquired in the step (S31) by utilizing a crystal oscillator precision regulation and control technology and an atomic clock discipline and time keeping technology to form a regulation and control quantity, and correcting the local clock in the time synchronization receiver in real time to realize the time synchronization terminal.
Further, step S1 further includes: the obtained precision satellite clock error and the satellite orbit correction number are recorded locally in the format of an SP3 file for subsequent analysis, and are simultaneously broadcast to a time synchronization receiver operating in real time in a real-time data stream mode through a TCP/IP protocol.
Further, step S13 includes modeling a stochastic process of the satellite-borne hydrogen clock, and using the stochastic process for the filtered estimation of the clock error.
Further, the step S14 specifically includes:
stability analysis is carried out on atomic clocks configured in different reference stations by adopting a time domain stability analysis method, and corresponding noise level coefficients and corresponding weight ratio relations of the atomic clocks are respectively determined based on Allen variance data of different smooth time intervals; then based on an atomic clock random differential model, estimating the state of the atomic clock of the station by Kalman filtering, and separating an initial clock error term, a frequency offset term and a deviation value of the atomic clock of the station relative to a reference in a network solution mode; and finally, obtaining a final reference correction quantity in a weighted average mode according to the weight ratio relation among the atomic clocks so as to obtain the refined satellite clock error reference.
The invention has the beneficial effects that:
1) the broadcasting data can be updated once per second in real time;
2) wide area (global coverage) time service can be realized;
3) high-precision (sub-nanosecond level) time service can be realized: the precision of the high-precision server time reference is better than 0.2ns (RMS) within a single day; the precision of the satellite clock error products broadcast by the server is better than 0.2ns (RMS), and the broadcast frequency of the products is 1 Hz; the global wide area coverage can be realized, and the long-baseline time service precision is better than 0.5 ns;
4) the cost is low, and is equivalent to the price of the traditional high-precision time service receiver, which is about one tenth of the price of the satellite bidirectional method.
Drawings
FIG. 1 is a flow chart of a WPT process of the present invention;
FIG. 2 is a flow chart of the time delivery process of the present invention;
FIG. 3 is a schematic structural diagram of a high-precision time product service platform according to the present invention;
fig. 4 is a schematic structural diagram of the time synchronization receiver of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings and examples, it being understood that the examples described below are intended to facilitate the understanding of the invention, and are not intended to limit it in any way. In the following embodiments, the beidou signal is taken as an example for explanation.
As shown in FIG. 1, the WPT method with wide area and accurate time service of the invention comprises the following steps:
s1: acquiring a time reference refined data product comprising a real-time precision satellite clock error product, a troposphere delay product and a satellite end FCB product, wherein the acquiring step comprises the following substeps:
s11: the server accesses the GNSS global observation data stream in real time through the real-time data stream comprehensive software, and decodes, stores, synchronizes in real time, packs and forwards the GNSS global observation data stream.
S12: based on the preprocessed IGS tracking station observation data stream in the global reference station data stream, a sliding window short arc comprehensive orbit determination method is adopted, real-time orbit determination is processed by establishing a short arc method equation and a short arc method equation to synthesize two parallel processes, and the satellite orbit real-time calculation method with high processing speed, fast initialization and stable numerical value is realized.
S13: and estimating the satellite clock error in real time by adopting a hybrid differential and convective dual-thread estimation method based on the IGS observation station observation data and the broadcast ephemeris in the preprocessed global reference station data stream.
In the estimation process of the satellite clock error, the multi-station troposphere delay, ambiguity parameters, satellite clock error parameters and the like need to be solved, and the efficiency of satellite clock error estimation can be influenced to a certain extent due to the large number of parameters to be estimated. Therefore, fast estimation is the technical basis for implementing the second-level update of the product. The invention adopts the estimation strategy of mixed difference and troposphere double threads to estimate the clock error. On the one hand, the "mixed difference" estimation strategy can avoid the estimation of non-difference mass ambiguity parameters; on the other hand, "troposphere double-thread processing" can reduce the troposphere parameters in the second-by-second estimation thread, further improve the estimation efficiency, and realize the second-by-second estimation of the satellite clock error product. In addition, considering that the Beidou-3 loads a new generation of high-performance hydrogen atomic clock, a random process of the satellite-borne hydrogen clock needs to be modeled, and the random process is used for filtering estimation of the clock error, so that the effect of further improving the clock error precision is achieved.
S14: and meanwhile, the UTC (k) time reference is introduced to be compared with the reference of the refined satellite clock difference, so that the safety and reliability of the obtained real-time precise satellite clock difference product are ensured.
Maintaining high precision time synchronization in a wide area requires introducing a stable, high precision time base as a reference time base in a time synchronization system. Because the traditional real-time satellite clock error estimation emphasizes real-time positioning application, the reference time deviation is generally not specially processed, and the time service precision is influenced. Therefore, the time reference introduced by the satellite clock difference needs to be further refined.
Aiming at the problem of unstable real-time satellite clock error reference, firstly, stability analysis is carried out on atomic clocks configured in different reference stations by adopting a time domain stability analysis method, and corresponding noise level coefficients and corresponding weight ratio relations of the atomic clocks are respectively determined based on Allen variance data of different smooth time intervals; then based on an atomic clock random differential model, estimating the state of the atomic clock of the station by Kalman filtering, and separating an initial clock error term, a frequency offset term and a deviation value of the clock error reference of the station clock relative to the reference in a network solution mode; and finally, obtaining a final reference correction quantity in a weighted average mode according to the weight ratio relation among the atomic clocks, thereby obtaining a refined time reference and obtaining a real-time precise satellite clock error product with the time being less than 0.2 ns. And finally, recording the precision satellite clock error and the satellite orbit correction number in the local in the format of an SP3 file for post analysis, and simultaneously broadcasting the precision satellite clock error and the satellite orbit correction number to a precision time service terminal which runs in real time in a real-time data stream mode through a TCP/IP protocol.
S15: a tropospheric delay product is generated based on the reference station zenith tropospheric wet delay.
S16: and estimating the UPD of the satellite terminal based on the Beidou tri-band observation value to obtain the FCB product of the satellite terminal.
The acquired time reference refinement data product is delivered to the time synchronization receiver over the internet (public communication network or private DCN) S2.
Aiming at the problem of low PPP convergence speed at present, the invention provides a rapid convergence technology, which comprises the following steps: combining and processing multi-system observation data, increasing the number of observation values and improving the geometric configuration of a satellite; optimizing a random model of altitude angle weighting, and weakening pseudo-range multi-path errors; researching a troposphere processing strategy, and accelerating the convergence of wide-area accurate time service by utilizing troposphere prior constraint; and replacing the non-ionosphere combined observed value of the pseudo range with large noise by using the single-frequency pseudo range observed value, and adding the Uofc observed value to perform combined processing. As shown in fig. 2, the method specifically includes the following sub-steps:
s21: the method comprises the steps of acquiring observation data in multi-constellation signals such as Beidou, GPS and the like accessed by a time synchronization receiver in real time, performing modeling error correction processing on the observation data, increasing the number of observation values, improving the geometric configuration of a satellite, optimizing a random model of altitude angle weighting, and weakening pseudo-range multi-path errors;
s22: carrying out differential correction decoding processing on the acquired real-time precise satellite clock error product, troposphere delay product and satellite end FCB product, and accelerating the convergence of wide-area precise time service;
s23: and for wide-area accurate time service, combining the processed observation data and the processed real-time accurate satellite clock error product, and estimating a receiver clock error parameter. In particular, the method adopts a short-baseline accurate time service mode, combines the processed observation data with the processed real-time accurate satellite clock error product, the troposphere delay product and the satellite-side FCB product, and estimates the local clock error parameters of the receiver.
S3: the method comprises the steps of acquiring pseudo-range data, broadcast ephemeris and other public satellite signals through a GNSS antenna, receiving a time reference refinement data product from a time service platform through the Internet, correcting a local clock of a receiver by using the time reference refinement data product, keeping the local clock and a satellite-borne clock in accurate synchronization, acquiring calibrated signals (the precision is less than 1ns) such as 1PPS and the like, and finally outputting the calibrated signals to an application party. Specifically, the method comprises the following substeps:
s31: acquiring a local clock error parameter of a receiver;
s32: and processing the acquired local clock difference parameter of the receiver to form a regulation and control quantity by utilizing a crystal oscillator precision regulation and control technology and an atomic clock discipline and time keeping technology, and correcting a local clock in the time synchronization receiver in real time to realize a time synchronization terminal.
Based on the WPT technology, the invention provides a WPT system which mainly comprises a high-precision time product service platform, a time transmission system and a time synchronization receiver.
The Beidou-based high-precision time product service platform is used for estimating and broadcasting high-precision satellite clock error correction numbers with precise time references in real time. In particular, the high-precision time product service platform comprises a dedicated server and a reference station data stream management unit, a satellite orbit real-time determination unit, a satellite clock error real-time estimation unit, a clock error reference refinement unit, a troposphere delay modeling unit and a satellite-side FCB calculation unit which are arranged at one or more positions, as shown in fig. 3. The server accesses GNSS global observation data through real-time data flow comprehensive software (not only can the real-time data flow of satellite observation stations all over the region be distributed, but also an IGS ultra-fast forecasting orbit product and an ephemeris data flow can be accessed at the same time); decoding and storing, synchronizing and forwarding accessed GNSS global observation data in real time by using a reference station data stream management unit; calculating the satellite orbit in real time by using a satellite orbit real-time determining unit and adopting a sliding window short arc comprehensive orbit determination method; estimating the satellite clock error in real time by using a satellite clock error real-time estimation unit and adopting a mixed differential and convection double-thread estimation method; a clock error reference refinement unit is utilized, and a time reference refinement method is adopted to refine the reference of the satellite clock error estimated in real time, so as to obtain a real-time precise satellite clock error product of less than 0.2 ns; generating a tropospheric delay product using a tropospheric delay modeling unit; and estimating a satellite end UPD by using a satellite end FCB calculation unit based on the Beidou tri-band observation value to obtain a satellite end FCB product. And finally, recording the precision satellite clock error and the satellite orbit correction number in the local in the format of an SP3 file for post analysis, and simultaneously broadcasting the precision satellite clock error and the satellite orbit correction number to a precision time service terminal which runs in real time in a real-time data stream mode through a TCP/IP protocol.
The time transfer system can be used as an information transfer channel between the high-precision time product platform and the time synchronization receiver through a public communication network or a special DCN. Therefore, under the time service architecture of the 'cloud pipe end', the time transmission system belongs to a macroscopic one-way information pipeline.
In particular, the time transfer system comprises: a modeling error correction processing unit, a differential correction number decoding processing unit and a receiver local clock error parameter estimation unit. The modeling error correction processing unit is used for performing modeling error correction processing on the obtained observation data in the Beidou signal accessed by the time synchronization receiver; the differential correction decoding processing unit is used for carrying out differential correction decoding processing on the acquired real-time precise satellite clock difference product, troposphere delay product and satellite end FCB product; the receiver local clock error parameter estimation unit is used for carrying out combined processing on the processed observation data and the processed real-time precise satellite clock error product in wide-area precise time service to estimate the receiver clock error parameter; and (3) accurately timing at a short baseline, combining the processed observation data with the processed real-time precise satellite clock error product, troposphere delay product and satellite-side FCB product, and estimating local clock error parameters of the receiver.
As shown in fig. 4, the time synchronization receiver includes an antenna, a radio frequency front end module, a baseband processing module, a clock conditioning module, and a local clock. The antenna is used for accessing a Beidou signal; the radio frequency front end module is used for carrying out down-conversion and filtering processing on the accessed Beidou signals; the baseband processing module is used for capturing and tracking the Beidou signal after down-conversion and filtering processing, extracting ephemeris, pseudo-range and carrier phase observation data from the acquired Beidou signal, and sending the ephemeris, pseudo-range and carrier phase observation data to a modeling error correction processing unit of the time transfer system for modeling error correction processing; the clock regulation and control module is used for processing the acquired local clock difference parameters of the receiver to form a regulation and control quantity by utilizing a crystal oscillator precision regulation and control technology and an atomic clock disciplining and time keeping technology, correcting the local clock in real time, finally realizing a time synchronization terminal, acquiring a calibrated signal (the precision is less than 1ns) such as 1PPS and the like, and finally outputting the calibrated signal to an application party.
The invention can be applied to the application fields of communication industry, railway time-frequency system, distributed radar, secondary radar and the like.
It will be apparent to those skilled in the art that various modifications and improvements can be made to the embodiments of the present invention without departing from the inventive concept thereof, and these modifications and improvements are intended to be within the scope of the invention.
Claims (6)
1. A WPT system for wide-area precise time service is characterized by comprising a high-precision time product service platform, a time transmission system and a time synchronization receiver,
the high-precision time product service platform comprises:
the system comprises a reference station data stream management unit, a global reference station data stream processing unit and a global reference station data stream processing unit, wherein the reference station data stream management unit is used for receiving and preprocessing global reference station data streams in real time;
the satellite orbit real-time determining unit is used for accessing an IGS tracking station observation data stream in the preprocessed global reference station data stream in real time and calculating a satellite orbit in real time;
the satellite clock error real-time estimation unit is used for accessing the IGS observation station observation data and the broadcast ephemeris in the preprocessed global reference station data stream in real time and estimating the satellite clock error in real time;
the clock error reference refinement unit is used for refining the reference of the satellite clock error estimated in real time by adopting a time reference refinement method to obtain a real-time precise satellite clock error product, and simultaneously, introducing UTC (k) time reference and reference comparison of the refined satellite clock error to ensure the safety and reliability of the obtained real-time precise satellite clock error product;
the troposphere delay modeling unit is used for processing the wet delay of the troposphere based on the zenith of the reference station and generating a troposphere delay product;
the satellite end FCB calculation unit is used for estimating a satellite end UPD based on the three-frequency observation value to obtain a satellite end FCB product;
the time transfer system includes:
the modeling error correction processing unit is used for performing modeling error correction processing on the obtained observation data in the GNSS signal accessed by the time synchronization receiver;
the differential correction decoding processing unit is used for carrying out differential correction decoding processing on the acquired real-time precise satellite clock error product, troposphere delay product and satellite end FCB product;
the receiver local clock error parameter estimation unit is used for carrying out combined processing on the processed observation data and the processed real-time precise satellite clock error product in wide-area precise time service to estimate the receiver clock error parameter; or accurately time-giving at a short baseline, and carrying out combined processing on the processed observation data, the processed real-time precise satellite clock error product, the troposphere delay product and the satellite-side FCB product to estimate local clock error parameters of the receiver;
the time synchronization receiver comprises a local clock and a clock regulation and control module, wherein the clock regulation and control module is used for processing the acquired local clock difference parameter of the receiver to form a regulation and control quantity by utilizing a crystal oscillator precision regulation and control technology and an atomic clock taming and punctuality technology, and correcting the local clock in real time to realize a time synchronization terminal.
2. The system of claim 1, wherein the time synchronization receiver further comprises an antenna, a radio frequency front end module, and a baseband processing module, the antenna is configured to access GNSS signals, the radio frequency front end module is configured to perform down-conversion and filtering processing on the accessed GNSS signals, the baseband processing module is configured to capture and track the down-converted and filtered GNSS signals, extract ephemeris, pseudorange, and carrier phase observation data therefrom, and send the extracted ephemeris, pseudorange, and carrier phase observation data to the modeled error correction processing unit of the time transfer module for modeled error correction processing.
3. A wide-area accurate time service method, called WPT method for short, is characterized by comprising the following steps:
s1: the method comprises the following steps of obtaining a time reference refined data product, wherein the time reference refined data product comprises a real-time precise satellite clock error product, a troposphere delay product and a satellite end FCB product, and comprises the following substeps:
s11: receiving and preprocessing a global reference station data stream in real time;
s12: calculating the satellite orbit in real time based on the IGS tracking station observation data flow in the preprocessed global reference station data flow;
s13: estimating satellite clock error in real time based on the IGS observation station observation data and the broadcast ephemeris in the preprocessed global reference station data stream;
s14: the method comprises the steps of adopting a time reference refinement method to refine the reference of the satellite clock error estimated in real time to obtain a real-time precise satellite clock error product, simultaneously introducing UTC (k) time reference, and comparing the UTC (k) time reference with the reference of the refined satellite clock error to ensure the safety and reliability of the obtained real-time precise satellite clock error product;
s15: generating a tropospheric delay product based on the reference station zenith tropospheric wet delay;
s16: estimating a satellite end UPD based on the three-frequency observation value to obtain a satellite end FCB product;
s2 time transfer for transferring the acquired time reference refined data product to a time synchronization receiver via the internet, comprising the sub-steps of:
s21: acquiring observation data in GNSS signals accessed by a time synchronization receiver in real time and carrying out modeling error correction processing on the observation data;
s22: carrying out differential correction decoding processing on the acquired real-time precise satellite clock error product, troposphere delay product and satellite end FCB product;
s23: for wide-area accurate time service, combining the observation data processed in the step S21 with the real-time accurate satellite clock error product processed in the step S22, and estimating a receiver clock error parameter; for short-baseline accurate time service, combining the observation data processed in the step S21 with the real-time accurate satellite clock error product, the troposphere delay product and the satellite-side FCB product processed in the step S22, and estimating local clock error parameters of the receiver;
s3: correcting the local clock in real time, comprising the following substeps:
s31: acquiring a local clock error parameter of a receiver;
s32: and (4) processing the local clock difference parameter of the receiver acquired in the step (S31) by utilizing a crystal oscillator precision regulation and control technology and an atomic clock discipline and time keeping technology to form a regulation and control quantity, and correcting the local clock in the time synchronization receiver in real time to realize the time synchronization terminal.
4. The method according to claim 3, wherein step S1 further comprises: the obtained precision satellite clock error and the satellite orbit correction number are recorded locally in the format of an SP3 file for subsequent analysis, and are simultaneously broadcast to a time synchronization receiver operating in real time in a real-time data stream mode through a TCP/IP protocol.
5. The method of claim 3, wherein step S13 further comprises modeling a stochastic process of the satellite-borne hydrogen clock and using it for the filtered estimation of the clock error.
6. The method according to claim 3, wherein the step S14 is specifically performed by:
stability analysis is carried out on the atomic clocks configured in different reference stations by adopting a time domain stability analysis method, and corresponding noise level coefficients and corresponding weight ratio relations of the atomic clocks are respectively determined based on Allen variance data of different smooth time intervals; then based on an atomic clock random differential model, estimating the state of the atomic clock of the station by Kalman filtering, and separating an initial clock error term, a frequency offset term and a deviation value of the atomic clock of the station relative to a reference in a network solution mode; and finally, obtaining a final reference correction quantity in a weighted average mode according to the weight ratio relation among the atomic clocks so as to obtain the refined satellite clock error reference.
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| CN112068165A (en) * | 2020-09-04 | 2020-12-11 | 北京航空航天大学 | High-precision time performance indirect detection method |
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Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101609143A (en) * | 2009-04-30 | 2009-12-23 | 中国科学院国家授时中心 | A kind of satellite timing method that strengthens based on wide area differential |
| CN103238041A (en) * | 2010-11-12 | 2013-08-07 | 内克斯特纳夫有限公司 | Wide area positioning system |
| CN105068096A (en) * | 2015-07-21 | 2015-11-18 | 上海司南卫星导航技术股份有限公司 | Non-difference correction distributed processing system based on reference station receiver and method |
| CN105700000A (en) * | 2016-04-13 | 2016-06-22 | 武汉大学 | Real-time dynamic precise positioning method of BeiDou navigation receiver |
| US20160274243A1 (en) * | 2015-03-17 | 2016-09-22 | Seiko Epson Corporation | Timing signal generation device and electronic apparatus |
| CN106292264A (en) * | 2016-08-23 | 2017-01-04 | 武汉羲和科技有限公司 | A kind of wide area accurate time transmission system strengthening system based on GNSS high accuracy |
| CN106705966A (en) * | 2016-09-18 | 2017-05-24 | 北京星网卫通科技开发有限公司 | Stable platform system capable of realizing high-precision absolute position and posture measurement |
| CN106850177A (en) * | 2016-12-15 | 2017-06-13 | 北京无线电计量测试研究所 | A kind of real-time time transmission method based on Static Precise Point Positioning |
| CN108536003A (en) * | 2018-05-24 | 2018-09-14 | 千寻位置网络有限公司 | Accurate time transmission system and method and time service service system |
| CN108919634A (en) * | 2018-08-13 | 2018-11-30 | 中国科学院国家授时中心 | A kind of three non-non-combined observation Time Transmission system and method for difference of frequency of Beidou |
| CN108931915A (en) * | 2018-05-08 | 2018-12-04 | 和芯星通科技(北京)有限公司 | Utilize time service method and device, the computer readable storage medium of navigation satellite |
| CN109001972A (en) * | 2018-08-13 | 2018-12-14 | 中国科学院国家授时中心 | A kind of Beidou wide area time dissemination system and method |
| CN109633701A (en) * | 2018-12-17 | 2019-04-16 | 北京跟踪与通信技术研究所 | GNSS timing receiver system delay calibration method based on punctual lab resources |
-
2019
- 2019-10-16 CN CN201910982975.1A patent/CN110780588B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101609143A (en) * | 2009-04-30 | 2009-12-23 | 中国科学院国家授时中心 | A kind of satellite timing method that strengthens based on wide area differential |
| CN103238041A (en) * | 2010-11-12 | 2013-08-07 | 内克斯特纳夫有限公司 | Wide area positioning system |
| US20160274243A1 (en) * | 2015-03-17 | 2016-09-22 | Seiko Epson Corporation | Timing signal generation device and electronic apparatus |
| CN105068096A (en) * | 2015-07-21 | 2015-11-18 | 上海司南卫星导航技术股份有限公司 | Non-difference correction distributed processing system based on reference station receiver and method |
| CN105700000A (en) * | 2016-04-13 | 2016-06-22 | 武汉大学 | Real-time dynamic precise positioning method of BeiDou navigation receiver |
| CN106292264A (en) * | 2016-08-23 | 2017-01-04 | 武汉羲和科技有限公司 | A kind of wide area accurate time transmission system strengthening system based on GNSS high accuracy |
| CN106705966A (en) * | 2016-09-18 | 2017-05-24 | 北京星网卫通科技开发有限公司 | Stable platform system capable of realizing high-precision absolute position and posture measurement |
| CN106850177A (en) * | 2016-12-15 | 2017-06-13 | 北京无线电计量测试研究所 | A kind of real-time time transmission method based on Static Precise Point Positioning |
| CN108931915A (en) * | 2018-05-08 | 2018-12-04 | 和芯星通科技(北京)有限公司 | Utilize time service method and device, the computer readable storage medium of navigation satellite |
| CN108536003A (en) * | 2018-05-24 | 2018-09-14 | 千寻位置网络有限公司 | Accurate time transmission system and method and time service service system |
| CN108919634A (en) * | 2018-08-13 | 2018-11-30 | 中国科学院国家授时中心 | A kind of three non-non-combined observation Time Transmission system and method for difference of frequency of Beidou |
| CN109001972A (en) * | 2018-08-13 | 2018-12-14 | 中国科学院国家授时中心 | A kind of Beidou wide area time dissemination system and method |
| CN109633701A (en) * | 2018-12-17 | 2019-04-16 | 北京跟踪与通信技术研究所 | GNSS timing receiver system delay calibration method based on punctual lab resources |
Non-Patent Citations (2)
| Title |
|---|
| YUN QING ET AL.: "Benefits of satellite clock modeling in BDS and Galileo orbit determination", 《ADVANCES IN SPACE RESEARCH》 * |
| 施闯 等: "北斗广域实时精密定位服务***研究与评估分析", 《测绘学报》 * |
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111866754A (en) * | 2020-06-29 | 2020-10-30 | 湖南省时空基准科技有限公司 | Wireless broadcast time service information processing method |
| CN112068165A (en) * | 2020-09-04 | 2020-12-11 | 北京航空航天大学 | High-precision time performance indirect detection method |
| CN113985719A (en) * | 2021-10-25 | 2022-01-28 | 中国科学院国家授时中心 | Sliding window-based pulsar time taming cesium atomic clock method |
| CN113985719B (en) * | 2021-10-25 | 2022-09-16 | 中国科学院国家授时中心 | Sliding window-based pulsar time taming cesium atomic clock method |
| CN114285514A (en) * | 2021-11-23 | 2022-04-05 | 泰康保险集团股份有限公司 | Clock synchronization method and device |
| CN114285514B (en) * | 2021-11-23 | 2024-04-23 | 泰康保险集团股份有限公司 | Clock synchronization method and device |
| CN114355758A (en) * | 2022-01-14 | 2022-04-15 | 中国人民解放军国防科技大学 | High-precision time tracing method based on Beidou satellite-based enhancement and precise ephemeris service |
| CN115128942B (en) * | 2022-06-17 | 2024-04-19 | 南京师范大学 | Instantaneous clock error recovery method and device after interruption of PPP time transfer data |
| CN115128942A (en) * | 2022-06-17 | 2022-09-30 | 南京师范大学 | Method and device for recovering instantaneous clock error after PPP time transmission data interruption |
| CN115616890A (en) * | 2022-09-28 | 2023-01-17 | 广西自贸区见炬科技有限公司 | Thermoelectric system clock error prediction error correction system |
| CN115933356A (en) * | 2023-01-09 | 2023-04-07 | 北京航空航天大学 | High-precision time synchronization system and method of virtual atomic clock |
| CN115933356B (en) * | 2023-01-09 | 2023-08-22 | 北京航空航天大学 | High-precision time synchronization system and method for virtual atomic clock |
| CN116299580A (en) * | 2023-01-19 | 2023-06-23 | 北京航空航天大学 | PPP time service oriented remote high-precision hardware time delay calibration system and method |
| CN116243591B (en) * | 2023-01-28 | 2023-09-29 | 北京航空航天大学 | Subnanosecond time service method integrating UTC (k) and Beidou broadcast ephemeris |
| CN116243591A (en) * | 2023-01-28 | 2023-06-09 | 北京航空航天大学 | Subnanosecond time service method integrating UTC (k) and Beidou broadcast ephemeris |
| CN116338752A (en) * | 2023-01-29 | 2023-06-27 | 北京航空航天大学 | Precise ambiguity fixing method for carrier phase single-difference time transfer |
| CN116338752B (en) * | 2023-01-29 | 2023-11-07 | 北京航空航天大学 | Precise ambiguity fixing method for carrier phase single-difference time transfer |
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