Beidou remote time service device and method fusing multi-type enhancement information

Abstract

The application belongs to the technical field of satellite navigation, and discloses a Beidou remote time service device and method fusing multiple types of enhanced information. The application establishes a time service architecture based on national standard time signals, solves the problem that different devices can only fuse one type of enhanced information by fusing multiple types of enhanced information, and helps to improve the universality and reliability of the time service device. The application not only realizes comparison between a user time source and a national standard time, but also can realize real-time control of an internal time frequency source of the device. In addition, the application also constructs a Beidou time service unified mathematical model fusing multiple types of enhanced information, considers the influence of ranging error in the Beidou PPP-B2b mode, and obtains comprehensive time reference correction information by using coordinate parameters of a reference station, so as to facilitate difference calculation with user station observation information for weakening, which is superior to the mode of only calculating the difference of clock information in the traditional time transfer, and helps to further improve the time service precision.

Description

Technical Field

[0001] This invention belongs to the field of satellite navigation and relates to a BeiDou remote timing device and method that integrates multiple types of enhanced information. Background Technology

[0002] To address the urgent need for high-precision national standard time information among distributed cluster time users, the traditional solution involves installing BeiDou common-view receivers at both individual cluster locations and the central station, and using pseudorange common-view time transfer methods to compare with the national standard time. However, the accuracy of this traditional time transfer method decreases unevenly as the distance between individual clusters and the central station increases, leading to a certain systematic deviation in time information between different clusters.

[0003] Meanwhile, traditional BeiDou time synchronization methods can only achieve a 16-minute timing frequency. Time users often need to equip themselves with high-precision cesium and hydrogen atomic clocks for compensation within this 16-minute period, further increasing their costs. Therefore, how to use BeiDou technology to achieve high-precision, low-cost time synchronization and accurately place the time information of the distributed cluster under the national standard time system is a pressing technical problem that needs to be solved in the current BeiDou time synchronization field. Summary of the Invention

[0004] The purpose of this invention is to propose a BeiDou remote timing device that integrates multiple types of enhanced information. By establishing a timing architecture based on the national standard time signal and integrating multiple types of enhanced information, it helps to solve the problem that timing devices at different stations can only integrate one type of enhanced information, which helps to improve the universality of the timing device and improve its accuracy.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A BeiDou remote timing device integrating multiple types of enhanced information includes a communication unit, a BeiDou tracking module unit, a rubidium clock module unit, and a core data processing unit;

[0007] The communication unit is used to receive real-time BeiDou observation data from the reference station and real-time BDS satellite orbit and clock difference product streams broadcast by the analysis center, and transmit them to the core data processing unit; the reference station is connected to a national standard time and frequency source.

[0008] The BeiDou tracking module unit is used to receive local BeiDou observation data and input it into the core data processing unit; the BeiDou tracking module unit includes BeiDou OEM boards;

[0009] The rubidium clock module unit is used to provide time and frequency input and external 1PPS second and 10MHz signal output for the Beidou tracking module unit. It includes a rubidium clock driving module, a rubidium clock module, a time and frequency source selector, an amplifier, and a clock distributor.

[0010] The time and frequency source selector controls whether the OEM board can connect to the 10MHz signal of the rubidium clock module;

[0011] The core data processing unit is used to send command requests to the Beidou tracking module unit based on external user settings.

[0012] Meanwhile, the core data processing unit uses the obtained BeiDou real-time observation data from the reference station, combined with the BDS real-time satellite orbit and clock error data or BDS PPP-B2b real-time information correction information broadcast by the analysis center, to obtain the clock error amount;

[0013] The obtained clock difference is accumulated into a fixed-length time window. The length of this time window is fixed, and a Kalman filter is used to smooth and predict the clock difference in one step to obtain the predicted value of the clock difference. The time window is then shifted by one step, where the step size is consistent with the time interval between two adjacent clock difference values.

[0014] The predicted clock difference is input into the rubidium clock driving module to drive the rubidium clock module. After driving, the rubidium clock module outputs a frequency of 10MHz and a pulse signal of 1PPS per second, ultimately achieving synchronization between the output signal and the national standard time signal.

[0015] Furthermore, based on the aforementioned BeiDou remote timing device that integrates multiple types of enhanced information, this invention also proposes a BeiDou remote timing method based on the aforementioned device that integrates multiple types of enhanced information, which adopts the following technical solution:

[0016] A BeiDou remote timing method that integrates multiple types of enhanced information includes the following steps:

[0017] Step 1. Based on the time and frequency source selector, select whether to collect local BeiDou observation data based on the rubidium clock module;

[0018] Step 2. Set the enhanced information source type; if the enhanced information source type is set to 0, it will be the real-time orbit and clock bias information of BDS satellite broadcast by the analysis center; if the enhanced information source type is set to 1, it will be the real-time correction information of BDS PPP-B2b.

[0019] Step 3. The communication unit is used to receive real-time BeiDou observation data from the reference station and real-time BDS satellite orbit and clock difference product streams, and transmit them to the core data processing unit; the reference station is connected to an external national standard time and frequency source;

[0020] Step 4. In the core data processing unit, based on the received local BeiDou observation data and the real-time BeiDou observation data of the reference station obtained by the communication unit, a GNSS carrier phase time transfer model that takes into account the ranging error correction is given.

[0021] Step 5. Using the real-time BeiDou observation data of the base station and combining it with the three-dimensional coordinates of its location, subtract the station-satellite geometric distance and modeling error from the observation equation of the base station to obtain the formula for the comprehensive time reference correction information at the base station.

[0022] Step 6. Using the time reference information of the base station and combined with the observation data of the user station, directly give the function model of BeiDou remote time synchronization that takes into account the information of the base station and integrates multiple types of enhanced information;

[0023] Based on the comprehensive time reference correction information formula obtained in step 5 and the BeiDou remote time service function model that takes into account the information of the reference station and integrates multiple types of enhancement information given in step 6, the clock difference between the local clock of the user station and the national standard time of the national time service center is directly obtained by calculation using the least squares principle and method.

[0024] Step 7. Utilize the obtained clock difference and accumulate it to a fixed-length time window. Fix the length of this time window, smooth it using a Kalman filter, and perform a one-step prediction to obtain the predicted clock difference. Then, shift the time window by one step; the step size should be consistent with the time interval between two adjacent clock difference measurements.

[0025] The predicted clock difference is input into the 10MHz rubidium clock driving module to drive the rubidium clock module. After driving, the rubidium clock module outputs a 10MHz frequency and a 1PPS second pulse signal, realizing the synchronization of the output signal with the national standard time signal.

[0026] The present invention has the following advantages:

[0027] 1. This invention proposes a BeiDou remote timing device based on the BeiDou Navigation Satellite System, which integrates multiple augmentation information. It can achieve high-precision timing not only based on real-time BDS satellite orbit and clock difference information broadcast by the analysis center via the Internet (via wired or wireless means), but also based on real-time BeiDou observation data from the reference station transmitted via the internal network (wired) and combined with BDS PPP-B2b augmentation information, achieving high-precision timing in scenarios without a public network. This invention completes an integrated device architecture for a BeiDou carrier phase timing method that integrates multiple augmentation information, effectively solving the problem that different timing devices located in two different locations can only process one type of augmentation information, thus improving the universality and reliability of the timing device.

[0028] 2. The BeiDou remote timing device proposed in this invention, which integrates multiple types of enhanced information, not only enables the comparison between the user's time source and the national standard time, facilitating the analysis of the spatiotemporal variation characteristics of the user's time source and the national standard time, but also achieves remote reproduction of the national standard time at the sub-nanosecond level through real-time control of the device's internal time frequency source. The BeiDou remote timing device proposed in this invention establishes a timing architecture based on the national standard time UTC (NTSC) signal, enabling a timing frequency of up to 1 second. This achieves the lowest-cost and most convenient traceability of user time signals to the national standard time, easily integrating the user's time system equipment's time reference into the national time system and facilitating information exchange with other national time system equipment.

[0029] 3. The BeiDou remote timing method proposed in this invention integrates multiple types of enhanced information, constructs a unified mathematical model for BeiDou timing that integrates multiple types of enhanced information, and further improves the unified mathematical model for BeiDou timing by taking into account the influence of ranging error in the BeiDou PPP-B2b mode, thereby improving the timing accuracy in the BeiDou PPP-B2b mode.

[0030] 4. The BeiDou remote timing method that integrates multiple types of enhanced information proposed in this invention makes full use of the coordinate parameters of the reference station to obtain comprehensive time reference correction information. It not only includes the time and frequency information of the reference station, but also the residual information of the BeiDou observation data error correction of the reference station. This facilitates the difference reduction with the observation information of the user station, which is significantly better than the traditional mode of only calculating the difference of clock information in time transmission, and helps to further improve the timing accuracy. Attached Figure Description

[0031] Figure 1 This is a structural block diagram of the BeiDou remote timing device that integrates multiple types of enhanced information in an embodiment of the present invention;

[0032] Figure 2 for Figure 1 A schematic diagram of a BeiDou remote timing device that integrates multiple types of enhanced information.

[0033] Figure 3 for Figure 1 A schematic diagram of the front panel of a BeiDou remote timing device that integrates multiple types of enhanced information;

[0034] Figure 4 for Figure 1 A schematic diagram of the rear panel of a BeiDou remote timing device that integrates multiple types of enhanced information;

[0035] Figure 5 for Figure 1 A schematic diagram of the front panel status of a Beidou remote timing device that integrates multiple types of enhanced information after it is working normally. Figure 5In the diagram, (a) represents equipment operating state one, (b) represents equipment operating state two, and (c) represents equipment operating state three. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0037] This invention addresses the urgent need for unified time signals among high-precision time users. Traditional time synchronization methods and terminal systems based on BDS pseudorange common-view suffer from accuracy degradation as the time transmission link distance increases, leading to inconsistencies in time information obtained by different users. Furthermore, the low precision of BDS pseudorange observations and the high cost of equipment severely restrict the application of time synchronization. This invention proposes a BeiDou remote time synchronization device and method that integrates multiple types of enhanced information. It comprehensively utilizes real-time BDS satellite orbit and clock difference information provided by the IGS analysis center, along with real-time BDS PPP-B2b correction information, and combines this with a high-precision time synchronization device based on the BeiDou satellite navigation system (the high-precision time synchronization device includes a communication unit, a rubidium clock module unit, a BeiDou tracking module unit, a core data processing unit, and a data storage unit), ultimately obtaining the national standard time UTC (NTSC) time information. This invention's time synchronization method features advanced algorithms, good continuous operation stability, and ease of operation, achieving high-precision information acquisition for users, and the method is simple to implement.

[0038] Example 1

[0039] like Figure 1 and Figure 2 As shown, the BeiDou remote timing device in this embodiment, which integrates multiple types of enhanced information, includes a communication unit, a rubidium clock module unit, a BeiDou tracking module unit, a core data processing unit, and a data storage unit.

[0040] The communication unit is used to receive real-time BeiDou observation data from the reference station and real-time BDS satellite orbit and clock bias product streams (i.e., RTCM format data streams of real-time BDS satellite orbit and clock bias information broadcast by the analysis center), and transmit them to the core data processing unit.

[0041] In this embodiment, the communication unit can use a wired network or a wireless network, such as a 4G / 5G module, to transmit data. The wired network is used for wired data transmission, while the 4G / 5G module is used for wireless data transmission.

[0042] The communication unit is based on the NTRIP data communication protocol and receives real-time BeiDou observation data from the reference station, which is connected to a national standard time and frequency source. At the same time, it pushes the data to the core data processing unit in real time according to the RTCM3.0 data stream format.

[0043] The rubidium clock module unit is used to provide time and frequency input and external 1PPS second and 10MHz signal output for the Beidou tracking module unit. It includes a rubidium clock driving module, a rubidium clock module, a time and frequency source selector, an amplifier, and a clock distributor.

[0044] The rubidium clock driving module is used to drive the rubidium clock module according to the predicted amount of the input clock difference. After driving, the rubidium clock module outputs a frequency of 10MHz and a pulse signal of 1PPS per second, and finally realizes the synchronization of the output signal with the national standard time signal.

[0045] The rubidium clock module is mainly used to provide a highly stable raw time frequency.

[0046] The time and frequency source selector is used to monitor the status of the rubidium clock module and other external time and frequency sources.

[0047] If the external time and frequency source is valid, the selector will automatically and seamlessly switch to the external time and frequency source as the priority; if the external time and frequency source is invalid, the selector will switch to the time and frequency source of the internal rubidium clock module.

[0048] The amplifier is used to receive the signal from the selector, amplify it to the appropriate level, provide buffer isolation, and perform filtering and level conversion to ensure that the signal has sufficient drive capability and quality.

[0049] Clock distributors are primarily used to receive signals from amplifiers, accurately replicate them, and distribute them to numerous output ports, delivering synchronization clock signals to various devices that require synchronization with extremely low skew.

[0050] The BeiDou tracking module unit is used to receive local BeiDou observation data and input it into the core data processing unit.

[0051] The Beidou tracking module unit includes a Beidou OEM board and a BDS antenna interface. The rubidium clock module controls whether the OEM board is connected to the 10MHz signal of the rubidium clock module through a time and frequency source selector.

[0052] If the time and frequency source selector detects an external 10MHz time and frequency reference signal input, the OEM board of the Beidou tracking module unit will perform local Beidou observation data acquisition based on the external 10MHz time and frequency reference signal. If no external 10MHz time and frequency reference signal input is detected, local Beidou observation data acquisition will be performed based on the rubidium clock module.

[0053] The core data processing unit is used to send command requests to the BeiDou tracking module unit through external user settings information, and to control the BeiDou tracking module unit to receive local BeiDou observation data.

[0054] Meanwhile, the core data processing unit can also use the obtained real-time BeiDou observation data from the reference station, combined with the real-time satellite orbit and clock error data of BDS or the real-time information correction information of BDS PPP-B2b broadcast by the analysis center, to obtain the clock error.

[0055] The obtained clock difference is accumulated into a fixed-length time window. The length of the time window is fixed, and a Kalman filter is used to smooth and predict it in one step. The time window is then shifted by one step.

[0056] The step size is consistent with the time interval between two adjacent clock difference measurements.

[0057] The predicted clock difference is input into the rubidium clock driving module to drive the rubidium clock module. After driving, the rubidium clock module outputs a frequency of 10MHz and a pulse signal of 1PPS per second, ultimately achieving synchronization between the output signal and the national standard time signal.

[0058] In this embodiment, the rubidium clock driving module is, for example, a phase micro-jump meter.

[0059] In addition, the core data processing unit can also store the status information and raw observation data of the user stations into the data storage module. The data storage unit is used to store the raw data from the base station and user stations, as well as clock error information.

[0060] The front panel of the Beidou remote timing device is used to set the enhanced information source type; if the enhanced information source is set to the RTS identifier, it is the real-time orbit and clock difference information of the BDS satellite broadcast by the analysis center, and the information source type is 0.

[0061] If the enhanced information source is set to the PPP-B2b identifier, then it is BDS PPP-B2b real-time correction information, and the information source type is 1.

[0062] The purpose of setting different enhanced information source types here is to enable remote time synchronization when the real-time satellite orbit and clock difference information provided by the analysis center is unavailable, thereby enhancing the time synchronization accuracy and reliability in multiple scenarios.

[0063] Based on the enhanced information source set by the local time synchronization device, the same time transmission model as the local time synchronization device is selected simultaneously on the time synchronization devices at different sites to eliminate systematic errors caused by different sites selecting different data models.

[0064] In addition, the BeiDou remote timing device in this embodiment also includes a data interface unit, a power management module unit, etc.

[0065] The data interface unit mainly includes an RS232 serial port, an HDMI port, and a USB port, which are used to connect to a computer, display the data processing process of the data processing module, and import external data, respectively.

[0066] The RS232 serial port connects to a computer to configure and adjust the internal program of the device.

[0067] The power management module unit is mainly used for converting external 220V voltage to power other module units.

[0068] like Figure 3 The components of the front panel of the BeiDou remote timing device in this embodiment are shown, wherein:

[0069] I.1. The leftmost button on the front panel is the receiver power switch.

[0070] When the device is off, the indicator light on the right is off; when the device is on, the indicator light is constantly lit in red.

[0071] I.2. The ESC button is the exit button when setting the enhanced information source.

[0072] I.3. There are a total of 6 indicator lights, from left to right:

[0073] The satellite search status display shows a solid green light indicating a satellite has been successfully locked, and a flashing red light indicating a satellite has not been locked.

[0074] Location status display: solid green indicates location is complete, flashing red indicates location is incomplete;

[0075] 4G / 5G communication signal quality: solid green indicates normal signal, flashing red indicates abnormal signal.

[0076] A solid green SYN light and a flashing red light indicate that synchronization with the national standard time signal has been completed and not yet achieved, respectively.

[0077] A solid green PPS-IN light indicates that the device is connected to an external second pulse signal, while a gray, off light indicates that the device is using the pulse signal from the internal rubidium clock.

[0078] A solid green REF-IN light indicates that the device is connected to an external frequency signal, while a gray, off light indicates that the device is using a frequency signal from an internal rubidium clock.

[0079] I.4. The LCD display shows information during the setup process and related status information such as positioning and time synchronization accuracy.

[0080] I.5. Function selection button, displayed on the LCD screen, is used to set the enhanced information source type.

[0081] like Figure 4The components of the front panel of the BeiDou remote timing device in this embodiment are shown, wherein:

[0082] II.1. The BNC connector corresponding to GNSS1 is responsible for connecting the external antenna of GNSS.

[0083] II.2. The TNC connector corresponding to REFI is responsible for connecting an external 10MHz frequency signal.

[0084] II.3. The TNC connector corresponding to REFO is responsible for outputting a 10 MHz frequency signal from the internally controlled time-frequency source.

[0085] II.4. The TNC connector for 4G is responsible for connecting the antenna for the 4G signal.

[0086] II.5. The TNC connector corresponding to PPS-IN is responsible for receiving the external 1PPS pulse signal.

[0087] II.6. The TNC connector corresponding to PPS-OUT is responsible for the output of the 1PPS pulse signal from the internal time-frequency source after control.

[0088] II.7. COM1 and COM2 are the COM ports displayed on the device, and are male and female respectively.

[0089] II.8. ETH is the network cable connection port.

[0090] II.9. USBC, USB1, and USB2 are all interfaces for the exchange of data, programs, scripts, and other files between the timing device and the external environment.

[0091] II.10. The SIM card is a communication card slot.

[0092] II.11. HDMI is a display interface.

[0093] II.12. The 24V interface is the power supply port for the timing device, which is powered by the adapter provided with the device.

[0094] The specific operation process of the BeiDou remote timing device that integrates multiple types of enhanced information in this embodiment is as follows:

[0095] 1. Connect the Beidou external antenna to the GNSS1 interface on the rear panel of the timing device of this invention, connect the communication antenna to the 4G interface and insert the SIM card into the SIM card slot, and connect the adapter to the power supply on the rear panel.

[0096] Without an external time and frequency standard, there is no need to connect an external time and frequency standard. With an external time and frequency standard, connect a 10MHz time frequency at REFI and an external 1PPS second pulse at PPS-IN.

[0097] 2. Press the power button on the front panel of the authorized device to start the device. After normal startup, the display panel will show the word "Normal". Use the selection buttons on the right to configure the enhanced information source, and press the "OK" button to confirm after selection.

[0098] If the real-time orbit and clock bias information of the BDS satellite broadcast by the analysis center is used, the augmentation information source is 0 and the ranging error S is zero; if the BDS PPP-B2b correction information source is used, the augmentation information source is 1 and the ranging error S is not zero.

[0099] This invention enables user equipment to switch freely between two enhanced information scenarios, enhancing the equipment's versatility. Furthermore, in the BeiDou PPP-B2b mode, ranging errors are taken into account, improving timing accuracy in this scenario.

[0100] 3. The front panel of the BeiDou remote timing equipment, which integrates multiple types of enhanced information, automatically displays tasks such as satellite search, normal positioning, time transfer, and time-frequency control. After normal operation, the display scrolls through the information. Figure 5 (a), (b), and (c) are shown in the image, and the scrolling interval is 5 seconds. Figure 5 (a), (b), and (c) in the text represent the equipment operating states one, two, and three, respectively.

[0101] Equipment operating status one indicates that the solution mode is the BeiDou timing model (PPP) that integrates multiple types of enhanced information, and the GNSS system is BDS (BDS). Equipment operating status two indicates the location of the equipment (longitude (Lon) and latitude (Lat)). Equipment operating status three indicates the elevation (Height) and receiver clock offset (Clkoff) of the equipment, in meters and nanoseconds, respectively.

[0102] Example 2

[0103] This embodiment 2 describes a BeiDou remote timing method that integrates multiple types of enhanced information. This method is based on the BeiDou remote timing device that integrates multiple types of enhanced information in the above embodiment 1.

[0104] Specifically, the BeiDou remote timing method that integrates multiple types of enhanced information in this embodiment includes the following steps:

[0105] Step 1. Based on the time and frequency source selector, select whether to collect local BeiDou observation data based on the rubidium clock module.

[0106] If the time and frequency source selector detects an external 10MHz time and frequency reference signal input, the OEM board of the Beidou tracking module unit will perform local Beidou observation data acquisition based on the external 10MHz time and frequency reference signal. If no external 10MHz time and frequency reference signal input is detected, local Beidou observation data acquisition will be performed based on the rubidium clock module.

[0107] Step 2. Set the enhanced information source type; if the enhanced information source type is set to 0, it will be the real-time orbit and clock bias information of BDS satellite broadcast by the analysis center; if the enhanced information source type is set to 1, it will be the real-time correction information of BDS PPP-B2b.

[0108] Step 3. The communication unit, for example based on a 4G / 5G module, receives real-time BeiDou observation data from the base station and real-time satellite orbit and clock difference product streams from BDS, and transmits them to the core data processing unit; the base station is connected to an external national standard time and frequency source.

[0109] Step 4. In the core data processing unit, the local BeiDou observation data received by the BeiDou tracking module and the real-time BeiDou observation data of the reference station obtained by the 4G / 5G module undergo multi-threaded data processing, and the GNSS carrier phase time transfer model that takes into account the ranging error correction and the calculation formula of the ranging error are given, as shown in formula (1):

[0110] (1)

[0111] In the formula Pseudo-distance observations Represents carrier phase observations. As an epoch identifier, GNSS satellite With receiver The distance between them For receiver clock bias, For satellite clock bias, At the speed of light, For tropospheric delay, For carrier phase ambiguity, This is pseudorange noise. For carrier phase noise, This represents the distance measurement error equivalent to the corresponding orbit and clock difference.

[0112] If the enhanced information source is set to 0, then it will be the real-time orbit and clock bias information of the BDS satellite broadcast by the analysis center, and the ranging error will be... The value is 0; if Enhanced Information Source 1 is set, it will be BDS PPP-B2b real-time correction information, and the ranging error will be 0. for .

[0113] The ranging error is The specific calculation method is as follows:

[0114] T represents the satellite clock bias, R represents the radial orbit bias, A represents the tangential orbit bias, and C represents the normal orbit bias. The specific values ​​of each parameter can be found in Table 1.

[0115] Table 1. Specific values ​​for each parameter

[0116]

[0117] in, and The constant coefficients, The values ​​are 0.99 and 0.98 in the GEO / IGSO and MEO constellations, respectively. The values ​​are 127 and 54 in the GEO / IGSO and MEO constellations, respectively.

[0118] Step 5. Using the real-time BeiDou observation data of the reference station UTC(NTSC) obtained by the communication unit, and combining it with the three-dimensional coordinates of its location, subtract the station-satellite geometric distance and modeling error from the observation equation of the reference station to obtain the formula for the comprehensive time reference correction information at the reference station, as shown in formula (2):

[0119] (2)

[0120] in This represents the pseudorange residual of the base station. This indicates the pseudorange observations at the base station. Indicates the distance between the satellite and the ground station. This represents the phase residual of the base station. This indicates the phase observations at the base station.

[0121] Step 6. Using the time reference information of the base station and combined with the observation data of the user station, directly give the function model of BeiDou remote timing that takes into account the information of the base station and integrates multiple types of enhanced information, as shown in formula (3):

[0122] (3)

[0123] In the formula This indicates the receiver clock bias parameter of the base station. This represents the relative distance measurement error between the user station and the base station. , For the satellite distance of the user station, The distance between the satellite and the ground station is the reference station.

[0124] Combining formulas (2) and (3), and using the least squares principle and method, the clock difference between the local clock of the user station and the national standard time of the national time service center is directly obtained by calculation, as shown in formula (4):

[0125] (4)

[0126] In the formula, This represents the clock difference between the user station's local clock and the national standard time of the national time service center at the current moment.

[0127] Step 7. Obtain clock driving quantity.

[0128] The obtained clock difference is accumulated into a fixed-length time window, such as 30 minutes. The length of this time window is fixed, and the clock difference is smoothed and predicted in one step using a Kalman filter to obtain the predicted value of the clock difference. The time window is then shifted by one step, where the step size is consistent with the time interval between two adjacent clock difference values.

[0129] The predicted clock difference (i.e., clock control quantity) is input into a 10MHz phase micro-jump meter (i.e., rubidium clock control module) to control the rubidium clock module. After control, the rubidium clock module outputs a 10MHz frequency and a 1PPS second pulse signal, ultimately achieving synchronization between the output signal and the national standard time signal. Thus, BeiDou remote time synchronization is completed.

[0130] Of course, the above description is only a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. It should be noted that any equivalent substitutions or obvious modifications made by those skilled in the art under the guidance of this specification fall within the scope of this specification and should be protected by the present invention.

Claims

1. A BeiDou remote timing device integrating multiple types of enhanced information, characterized in that, It includes a communication unit, a BeiDou tracking module unit, a rubidium clock module unit, and a core data processing unit; The communication unit is used to receive real-time BeiDou observation data from the reference station and real-time BDS satellite orbit and clock difference product streams broadcast by the analysis center, and transmit them to the core data processing unit; the reference station is connected to a national standard time and frequency source. The BeiDou tracking module unit is used to receive local BeiDou observation data and input it into the core data processing unit; The BeiDou tracking module includes BeiDou OEM boards; The rubidium clock module unit is used to provide time and frequency input and external 1PPS second and 10MHz signal output for the Beidou tracking module unit. It includes a rubidium clock driving module, a rubidium clock module, a time and frequency source selector, an amplifier, and a clock distributor. The time and frequency source selector controls whether the OEM board can connect to the 10MHz signal of the rubidium clock module; The core data processing unit is used to send command requests to the Beidou tracking module unit based on external user settings. Meanwhile, the core data processing unit uses the obtained BeiDou real-time observation data from the reference station, combined with the BDS real-time satellite orbit and clock error data or BDS PPP-B2b real-time information correction information broadcast by the analysis center, to obtain the clock error amount; The obtained clock difference is accumulated into a fixed-length time window. The length of this time window is fixed, and a Kalman filter is used to smooth and predict the clock difference in one step to obtain the predicted value of the clock difference. The time window is then shifted by one step, where the step size is consistent with the time interval between two adjacent clock difference values. The predicted clock difference is input into the rubidium clock driving module to drive the rubidium clock module. After driving, the rubidium clock module outputs a frequency of 10MHz and a pulse signal of 1PPS per second, ultimately achieving synchronization between the output signal and the national standard time signal.

2. The BeiDou remote timing device integrating multiple types of enhanced information according to claim 1, characterized in that, The time-frequency source selector automatically configures the time-frequency source type; If the time and frequency source selector detects an external 10MHz time and frequency reference signal input, the OEM board will perform local BeiDou observation data acquisition based on the external 10MHz time and frequency reference signal. If no external 10MHz time and frequency reference signal input is detected, local BeiDou observation data is collected based on the rubidium clock module.

3. The BeiDou remote timing device integrating multiple types of enhanced information according to claim 1, characterized in that, The front panel of the Beidou remote timing device is used to set the enhanced information source type; if the enhanced information source is set to RTS identifier, it is the real-time orbit and clock difference information of BDS satellite broadcast by the analysis center, and the information source type is 0. If the enhanced information source is set to the PPP-B2b identifier, then it is BDS PPP-B2b real-time correction information, and the information source type is 1.

4. The BeiDou remote timing device integrating multiple types of enhanced information according to claim 1, characterized in that, The communication unit includes a wired network or a 4G / 5G module. The communication unit is based on the NTRIP data communication protocol and receives real-time BeiDou observation data from the reference station in real time. The reference station is connected to a national standard time and frequency source. Meanwhile, the communication unit pushes the data to the core data processing unit in real time according to the RTCM3.0 data stream format.

5. The BeiDou remote timing device integrating multiple types of enhanced information according to claim 1, characterized in that, The BeiDou remote timing device that integrates multiple types of enhanced information also includes a data storage unit; wherein, the data storage unit is used to store the raw BDS observation data of the reference station and user station, as well as the clock difference information.

6. The BeiDou remote timing device integrating multiple types of enhanced information according to claim 1, characterized in that, Based on the enhanced information source type set by the local time synchronization device, the same time transmission model as the local time synchronization device is selected simultaneously on the time synchronization devices at different sites to eliminate systematic errors caused by different sites selecting different data models.

7. A BeiDou remote timing method integrating multiple types of enhanced information, based on a BeiDou remote timing device integrating multiple types of enhanced information as described in any one of claims 1 to 6, characterized in that, The method includes the following steps: Step 1. Based on the time and frequency source selector, select whether to collect local BeiDou observation data based on the rubidium clock module; Step 2. Set the enhanced information source type; if the enhanced information source type is set to 0, it will be the real-time orbit and clock bias information of BDS satellite broadcast by the analysis center; if the enhanced information source type is set to 1, it will be the real-time correction information of BDS PPP-B2b. Step 3. The communication unit is used to receive real-time BeiDou observation data from the reference station and real-time BDS satellite orbit and clock difference product streams, and transmit them to the core data processing unit; the reference station is connected to an external national standard time and frequency source; Step 4. In the core data processing unit, based on the received local BeiDou observation data and the real-time BeiDou observation data of the reference station obtained by the communication unit, a GNSS carrier phase time transfer model that takes into account the ranging error correction is given. Step 5. Using the real-time BeiDou observation data of the base station and combining it with the three-dimensional coordinates of its location, subtract the station-satellite geometric distance and modeling error from the observation equation of the base station to obtain the formula for the comprehensive time reference correction information at the base station. Step 6. Using the time reference information of the base station and combined with the observation data of the user station, directly give the function model of BeiDou remote time synchronization that takes into account the information of the base station and integrates multiple types of enhanced information; Based on the comprehensive time reference correction information formula obtained in step 5 and the BeiDou remote time service function model that takes into account the information of the reference station and integrates multiple types of enhancement information given in step 6, the clock difference between the local clock of the user station and the national standard time of the national time service center is directly obtained by calculation using the least squares principle and method. Step 7. Utilize the obtained clock difference and accumulate it to a fixed-length time window. Fix the length of this time window, smooth it using a Kalman filter, and perform a one-step prediction to obtain the predicted clock difference. Then, shift the time window by one step; the step size should be consistent with the time interval between two adjacent clock difference measurements. The predicted clock difference is input into the 10MHz rubidium clock driving module to drive the rubidium clock module. After driving, the rubidium clock module outputs a 10MHz frequency and a 1PPS second pulse signal, realizing the synchronization of the output signal with the national standard time signal.

8. The BeiDou remote timing method for integrating multiple types of enhanced information according to claim 7, characterized in that, In step 4, the GNSS carrier phase time transfer model that takes into account ranging error correction is shown in formula (1): （1） In the formula Indicates pseudo-distance observations, Represents carrier phase observations. As an epoch identifier, GNSS satellite With receiver The distance between them For receiver clock bias, For satellite clock bias, At the speed of light, For tropospheric delay, For carrier phase ambiguity, This is pseudorange noise. For carrier phase noise, This represents the distance measurement error equivalent to the corresponding orbit and clock difference; If the enhanced information source is set to 0, then it will be the real-time orbit and clock bias information of the BDS satellite broadcast by the analysis center, and the ranging error will be... The value is 0; if Enhanced Information Source 1 is set, it will be BDS PPP-B2b real-time correction information, and the ranging error will be 0. for ; The ranging error is The calculation formula is shown below; In the formula, T represents the satellite clock bias, R represents the radial orbit bias, A represents the tangential orbit bias, and C represents the normal orbit bias. and is a constant coefficient.

9. The BeiDou remote timing method for integrating multiple types of enhanced information according to claim 8, characterized in that, In step 5, the integrated time base correction information at the base station is shown in formula (2): (2) in This represents the pseudorange residual of the base station. This indicates the pseudorange observations at the base station. Indicates the distance between the satellite and the ground station. This represents the phase residual of the base station. This indicates the phase observations at the base station.

10. The BeiDou remote timing method for integrating multiple types of enhanced information according to claim 9, characterized in that, In step 6, the function model for BeiDou remote time synchronization is shown in formula (3): （3） In the formula This indicates the receiver clock bias parameter of the base station. This refers to the relative ranging error between the user station and the base station. , For the satellite distance of the user station, The satellite-to-ground distance of the reference station; Combining formulas (2) and (3), and using the least squares principle and method, the clock difference between the local clock of the user station and the national standard time of the national time service center is directly obtained by calculation, as shown in formula (4): (4) In the formula, This represents the clock difference between the user station's local clock and the national standard time of the national time service center at the current moment.

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