Satellite-based time service method and apparatus, electronic device, and storage medium

Abstract

The application discloses a satellite-based time service method and device, electronic equipment and storage medium, comprising: receiving a short message signal of a geosynchronous satellite, the short message signal comprising an uplink time delay of a standard time sent by a ground control center to the geosynchronous satellite; receiving a navigation message of the geosynchronous satellite and obtaining a correction parameter of coordinated universal time from the navigation message; calculating a downlink time delay of the geosynchronous satellite to a time service device based on the uplink time delay; calculating a local time of the time service device by using the standard time, the uplink time delay, the correction parameter and the downlink time delay; and performing time service by using the local time, without positioning the time service device to calculate the downlink time delay, and without occupying the calculation resources of the ground control center, compared with the prior art, the time service time is shortened, the influence of the calculated position on the time service precision is reduced, and the time service speed and precision are improved.

Description

Technical Field

[0001] This invention relates to the field of time synchronization technology, and more particularly to a satellite-based time synchronization method, apparatus, electronic device, and storage medium. Background Technology

[0002] Time synchronization is crucial in fields such as network communication and electronic computing. Currently, it is mainly achieved through satellite time synchronization, which involves transmitting or relaying standard time via satellite. It is one of the various time synchronization methods.

[0003] In satellite time synchronization, the accuracy of the time synchronization is related to the propagation delay of the standard time. In existing technologies, one method of satellite time synchronization is the one-way time synchronization method based on RNSS / GNSS. The propagation delay is related to the distance between the time synchronization equipment and the satellite. Therefore, the time synchronization equipment needs to obtain its own position in order to accurately calculate the propagation delay. The position of the time synchronization equipment is obtained through satellite positioning, which requires the time synchronization equipment to acquire at least 4 satellites. Furthermore, calculating the position of the time synchronization equipment takes a long time. Another method is the two-way time synchronization based on RDSS (Radio Determination Satellite Service). This method requires the user to send a timing request signal to the ground control center. After receiving the user's timing request, the control center calculates the user's propagation delay and sends the propagation delay back to the user. This method relies on the computing resources of the ground control center. Summary of the Invention

[0004] This invention provides a satellite-based time synchronization method, apparatus, electronic device, and storage medium to solve the problems of existing satellite time synchronization methods that require multiple satellites to calculate the position of the time synchronization device, which is time-consuming, or that rely on the computing resources of the ground control center.

[0005] In a first aspect, the present invention provides a satellite-based time synchronization method, applied to a time synchronization device, comprising:

[0006] Receive short message signals from geostationary satellites, the short message signals including the uplink delay Tup of standard time T0 sent by the ground control center to the geostationary satellite;

[0007] Receive navigation messages from the geostationary satellite and obtain the Coordinated Universal Time (UTCp) correction parameter from the navigation messages;

[0008] Calculate the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup.

[0009] The local time T1 of the timing device is calculated using the standard time T0, the uplink delay Tup, the correction parameter UTCp, and the downlink delay Tdown;

[0010] The local time T1 is used for time synchronization.

[0011] Optionally, before calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup, the method further includes:

[0012] Determine whether the local memory of the timing device stores the downlink delay Tdown;

[0013] If so, read the downlink delay Tdown from the local memory of the timing device;

[0014] If not, perform the step of calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup.

[0015] Optionally, calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup includes:

[0016] The geostationary satellite sends a timing request to the ground control center. After receiving the timing request, the geostationary satellite forwards the timing request to the ground control center. When the ground control center receives the timing request, it calculates the total one-way propagation delay Tc from the ground control center to the timing device.

[0017] The total one-way propagation delay Tc is received from the geostationary satellite;

[0018] The difference between the total one-way propagation delay Tc and the uplink delay Tup is calculated and used as the downlink delay Tdown.

[0019] Optionally, after calculating the difference between the total one-way propagation delay Tc and the uplink delay Tup as the downlink delay Tdown, the method further includes:

[0020] The downlink delay Tdown is stored in the local memory of the timing device.

[0021] Optionally, after storing the downlink delay Tdown into the local memory of the timing device, the method further includes:

[0022] Determine whether a preset event has been detected;

[0023] If so, perform the step of calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup.

[0024] Optionally, calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup includes:

[0025] The downlink delay Tdown is determined to be equal to the uplink delay Tup.

[0026] Optionally, calculating the local time T1 of the timing device using the standard time T0, the uplink delay Tup, the correction parameter UTCp, and the downlink delay Tdown includes:

[0027] Obtain device latency Td;

[0028] Calculate the difference between the standard time T0 and the correction parameter UTCp;

[0029] The sum of the difference, the uplink delay Tup, the downlink delay Tdown, and the device delay Td is calculated to serve as the local time T1 of the timing device.

[0030] Secondly, the present invention provides a satellite-based timing device for use in timing equipment, comprising:

[0031] The satellite short message signal receiving module is used to receive short message signals from geostationary satellites. The short message signals include the uplink delay Tup of the standard time T0 sent by the ground control center to the geostationary satellite.

[0032] The Coordinated Universal Time Correction Parameter Determination Module is used to receive the navigation message from the geostationary satellite and obtain the Coordinated Universal Time Correction Parameter UTCp from the navigation message;

[0033] The downlink latency calculation module is used to calculate the downlink latency Tdown from the geostationary satellite to the timing device based on the uplink latency Tup.

[0034] The local time calculation module is used to calculate the local time T1 of the time synchronization device using the standard time T0, the uplink delay Tup, the correction parameter UTCp, and the downlink delay Tdown;

[0035] The time synchronization module is used to synchronize the local time T1.

[0036] Thirdly, the present invention provides an electronic device, the electronic device comprising:

[0037] At least one processor; and

[0038] A memory communicatively connected to the at least one processor; wherein,

[0039] The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the satellite-based timing method according to any one of the first aspects of the present invention.

[0040] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the satellite-based timing method according to any one of the first aspects of the present invention.

[0041] In the satellite-based timing method of this invention, the timing device can receive short message signals from geostationary satellites. These short message signals include: an uplink delay Tup from the ground control center to the geostationary satellite (standard time T0); receiving navigation messages from the geostationary satellite and obtaining the Coordinated Universal Time (UTCp) correction parameter from the navigation messages; calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup; calculating the local time T1 of the timing device using the standard time T0, the uplink delay Tup, the correction parameter UTCp, and the downlink delay Tdown; and using the local time... The timing method of this invention, which performs timing synchronization at interval T1, can interpret the uplink delay Tup of the standard time T0 transmitted by the geostationary satellite from the short message signal of the geostationary satellite, and calculate the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup. It does not require positioning the timing device to calculate the downlink delay Tdown, nor does it occupy the computing resources of the ground control center. Compared with the prior art, which calculates the delay after solving the position of the timing device by at least 4 satellites, it shortens the timing synchronization time, avoids the influence of the calculated position on the timing synchronization accuracy, and improves the timing synchronization speed and accuracy.

[0042] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A schematic diagram showing the locations of satellites, ground control centers, and timing equipment in existing timing methods. Figure 2 This is a flowchart of a satellite-based time synchronization method provided in Embodiment 1 of the present invention;

[0045] Figure 3 This is a schematic diagram illustrating time synchronization via a geostationary satellite in an embodiment of the present invention;

[0046] Figure 4 This is a flowchart of a satellite-based time synchronization method provided in Embodiment 2 of the present invention;

[0047] Figure 5 This is a flowchart of a satellite-based time synchronization method provided in Embodiment 3 of the present invention;

[0048] Figure 6 This is a schematic diagram illustrating the propagation time difference between the closest and farthest points between the satellite and the Earth in an embodiment of the present invention.

[0049] Figure 7 This is a schematic diagram of the structure of a satellite-based timing device provided in Embodiment 4 of the present invention;

[0050] Figure 8 This is a schematic diagram of the structure of the electronic device provided in Embodiment 5 of the present invention. Detailed Implementation

[0051] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0052] like Figure 1 The diagram shows a satellite, a ground control center, and a timing device. In existing technologies, the ground control center and timing device are typically located first using multiple satellites (satellites 1-4) to obtain their precise positions. Then, the distances from the ground control center and timing device to the satellites are calculated using their precise positions. The uplink and downlink delays of the signal propagation are then calculated based on these distances. The timing device then provides timing information based on these uplink and downlink delays. This timing method requires multiple satellites (satellites 1-4) to accurately locate the ground control center and timing device. The positioning calculation process is time-consuming, and the timing accuracy depends on the positioning accuracy.

[0053] To address the aforementioned issues, the satellite-based time synchronization method provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0054] Example 1

[0055] Figure 2This is a flowchart of a satellite-based time synchronization method provided in Embodiment 1 of the present invention. This embodiment is applicable to situations where time synchronization is performed after the time synchronization device is calibrated based on a satellite. This method can be executed by a satellite-based time synchronization device, which can be implemented in hardware and / or software and can be configured in an electronic device. Figure 2 As shown, this satellite-based timing method includes:

[0056] S201. Receive short message signals from geostationary satellites. The short message signals include the uplink delay Tup from the ground control center to the geostationary satellite at standard time T0.

[0057] In this embodiment, the satellite used for time synchronization is a geostationary satellite. Geostationary satellites are stationary relative to the Earth. An exemplary geostationary satellite can be a geostationary satellite (GEO) used as a short message satellite in the BeiDou-3 system. The frequency band of the outgoing signal of the geostationary satellite in the BeiDou-3 system is 2491.75MHz, which is 900MHz different from the frequency band of 1575.42MHz of traditional RNSS / GNSS time synchronization devices, thus exhibiting high anti-interference capability.

[0058] The ground control center can be a time service center located on the ground, which can inject standard time T0 into the geostationary satellite according to a preset cycle. For example, the ground control center can be the national time service center of each country.

[0059] Uplink latency Tup can be the time required for the ground control center to send standard time T0 to the geostationary satellite, such as... Figure 3 As shown, since the satellite is a geostationary satellite, the location of the ground control center can be precisely positioned in advance and fixed. Therefore, the distance from the ground control center to the geostationary satellite can be determined. By calculating the ratio of this distance to the propagation speed of electromagnetic waves, the uplink delay Tup can be obtained. When the ground control center sends the standard time T0 to the geostationary satellite, it can carry this uplink delay Tup. The uplink delay Tup is different for different ground control centers.

[0060] When a geostationary satellite receives the standard time T0 sent by the ground control center, it can generate a short message signal including the standard time T0 and the uplink delay Tup, and send the short message signal to the timing device. The timing device can be a ground-based device that needs to provide time synchronization. In one example, the timing device can be various network devices, such as electronic devices such as switches and hosts in communication base stations. In another example, the timing device can also be various mobile terminals, such as mobile phones. The timing device can capture the short message signal sent by the geostationary satellite and calculate the standard time T0 and the uplink delay Tup from the short message signal.

[0061] S202. Receive navigation messages from geostationary satellites and obtain the Coordinated Universal Time (UTCp) correction parameter from the navigation messages.

[0062] Due to the unevenness and long-term slowing of the Earth's rotation, the accumulated error between Universal Time (UT) and International Atomic Time (IAT) is increasing. When the difference between UT and IAT reaches ±0.9 seconds, the International Bureau of Weights and Measures will uniformly adjust Coordinated Universal Time by adding or subtracting 1 second at the end of the year or in the middle of the year. The BeiDou time system started on January 1, 2006, and the correction parameter UTCp for Coordinated Universal Time in the BeiDou system is 4 seconds. The navigation message of the geostationary satellite can include this correction parameter UTCp, so the correction parameter UTCp can be obtained from the navigation message.

[0063] S203. Calculate the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup.

[0064] In one embodiment, the timing device can send a timing request to the ground control center via a geostationary satellite. After receiving the timing request, the ground control center calculates the total one-way propagation delay Tc, which is the total delay of the ground control center transmitting signals to the timing device via the geostationary satellite. The difference between the total one-way propagation delay Tc and the uplink delay Tup is calculated, and this difference is the downlink delay Tdown from the geostationary satellite to the timing device.

[0065] In another embodiment, since the ground control center and timing equipment are stationary relative to the geostationary satellite, when the timing accuracy requirement is not high, the downlink delay Tdown can be set to be equal to the uplink delay Tup.

[0066] S204. Calculate the local time T1 of the time synchronization device using standard time T0, uplink delay Tup, correction parameter UTCp, and downlink delay Tdown.

[0067] Specifically, after obtaining the pre-calibrated device delay Td, the local time T1 of the time synchronization device can be calculated using the following formula:

[0068] T1 = T0 - UTCp + Tup + Tdown + Td

[0069] If the current local time of the time synchronization device is the same as the calculated local time T1, then there is no need to adjust the local time of the time synchronization device. If the current local time of the time synchronization device is not the same as the calculated local time T1, then the local time of the time synchronization device should be adjusted to T1.

[0070] S205. Use local time T1 for time synchronization.

[0071] Local time T1 is the time after the timing device is synchronized with the time of the geostationary satellite. Local time T1 is synchronized with the time of the ground control center. The timing device can use this local time T1 to provide time synchronization to its various modules or to other devices outside the timing device.

[0072] In the satellite-based timing method of this invention, the timing device can receive short message signals from geostationary satellites. These short message signals include: an uplink delay Tup from the ground control center to the geostationary satellite (standard time T0); receiving navigation messages from the geostationary satellite and obtaining the Coordinated Universal Time (UTCp) correction parameter from the navigation messages; calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup; and calculating the local time T1 of the timing device using the standard time T0, the uplink delay Tup, the correction parameter UTCp, and the downlink delay Tdown. The local time T1 is used for time synchronization. The time synchronization method of this embodiment can interpret the uplink delay Tup of the standard time T0 transmitted by the geostationary satellite from the short message signal of the geostationary satellite, and calculate the downlink delay Tdown from the geostationary satellite to the time synchronization device based on the uplink delay Tup. It does not require positioning the time synchronization device to calculate the downlink delay, nor does it occupy the computing resources of the ground control center. Compared with the prior art, which calculates the delay after solving the position of the time synchronization device by at least 4 satellites, it shortens the time synchronization time, reduces the influence of the calculated position on the time synchronization accuracy, and improves the time synchronization speed and accuracy.

[0073] Example 2

[0074] Figure 4 This is a flowchart of a satellite-based timing method provided in Embodiment 2 of the present invention. This embodiment optimizes Embodiment 1 as described above. Figure 4 As shown, this satellite-based timing method includes:

[0075] S401. Receive short message signals from geostationary satellites. The short message signals include the uplink delay Tup from the ground control center to the geostationary satellite at standard time T0.

[0076] like Figure 3 As shown, the satellite used for time synchronization in this embodiment is a geostationary satellite. For example, a geostationary satellite used as a short message satellite in the BeiDou-3 system can be used. The ground control center can inject standard time T0 and uplink delay Tup into the geostationary satellite according to a preset period. When the geostationary satellite receives the standard time T0 sent by the ground control center, it can generate a short message signal including standard time T0 and uplink delay Tup, and send the short message signal to the time synchronization device. The time synchronization device can calculate the standard time T0 and uplink delay Tup from the short message signal of the geostationary satellite.

[0077] S402. Receive navigation messages from geostationary satellites and obtain the Coordinated Universal Time (UTCp) correction parameter from the navigation messages.

[0078] In this embodiment, the navigation message of the geostationary satellite may include the correction parameter UTCp, thereby obtaining the Coordinated Universal Time (UTCp) correction parameter from the navigation message.

[0079] In another embodiment, after the timing device obtains the Coordinated Universal Time (UTCp) correction parameter, it can store the correction parameter UTCp in local memory, so that it does not need to obtain the correction parameter UTCp from the navigation message of the geostationary satellite again before the next update of the UTC correction parameter UTCp.

[0080] S403. Determine whether the local memory of the timing device stores the downlink delay Tdown.

[0081] The downlink delay Tdown is the delay in signal transmission from the geostationary satellite to the timing device. Since the timing device can be a stationary device, such as a host or switch in a communication base station, and the geostationary satellite is stationary relative to the Earth, the distance between the timing device and the geostationary satellite remains constant, and the downlink delay Tdown remains fixed. After the timing device is powered on for the first time for time synchronization, the downlink delay Tdown can be stored in the local memory. It can be determined whether the local memory of the timing device stores the downlink delay Tdown. If it does, then S404 is executed. Otherwise, it means that the timing device may have cleared the stored downlink delay Tdown after a long period of operation, or it is the timing device that is powered on for the first time, or it is the timing device after a reset. Then S405 can be executed.

[0082] S404: Read the downlink delay Tdown from the local memory of the timing device.

[0083] When the local memory of the timing device stores the downlink delay Tdown, the downlink delay Tdown can be read directly from the local memory to improve the speed of obtaining the downlink delay Tdown and further improve the timing speed.

[0084] S405. A timing request is sent to the ground control center via a geostationary satellite. After receiving the timing request, the geostationary satellite forwards it to the ground control center. When the ground control center receives the timing request, it calculates the total one-way propagation delay Tc from the ground control center to the timing equipment.

[0085] When the local memory of the timing device does not store the downlink delay Tdown, the timing device can send a timing request to the ground control center via a geostationary satellite, and the ground control center can calculate the total one-way propagation delay Tc from the ground control center to the timing device.

[0086] In one embodiment, after receiving a timing request, the ground control center sends a signal to the timing device via a geostationary satellite at time t1. Upon receiving the signal, the timing device responds by sending a response signal to the ground control center via a geostationary satellite. The ground control center receives the response signal at time t2. Using time t1 and time t2, the total one-way propagation delay Tc from the ground control center to the timing device can be calculated, and the total one-way propagation delay Tc is sent to the timing device via a geostationary satellite.

[0087] S406, Total one-way propagation delay Tc from geostationary satellite reception.

[0088] After the ground control center sends the total one-way propagation delay Tc to the geostationary satellite, the geostationary satellite forwards the total one-way propagation delay Tc, and the timing equipment can receive the total one-way propagation delay Tc from the geostationary satellite.

[0089] S407. Calculate the difference between the total one-way propagation delay Tc and the uplink delay Tup, and use it as the downlink delay Tdown.

[0090] like Figure 3 As shown, the total one-way propagation delay Tc is the total delay of the signal from the ground control center being transmitted to the timing equipment via the geostationary satellite, i.e., Tc = Tup + Tdown. Therefore, Tdown = Tc - Tup can be calculated.

[0091] S408. Store the downlink delay Tdown to the local memory of the timing device.

[0092] After the timing device is powered on for the first time or after a reset and power-on, when the downlink delay Tdown is calculated, it is stored in the local memory. Since the distance between the timing device and the geostationary satellite is relatively fixed, the downlink delay Tdown remains unchanged. After a power outage and power-on, the downlink delay Tdown can be read directly from the local memory to improve the timing speed.

[0093] S409. Determine whether a preset event has been detected.

[0094] In this embodiment, the preset event can be receiving a time synchronization operation triggered by the user. For example, after the location of the timing device changes, the user triggers the timing device to resynchronize. For instance, the user removes the timing device from location A in the communication base station and installs it on the communication base station at location B, which is far from location A, causing the distance between the timing device and the geostationary satellite to change. The user can trigger the timing device to synchronize the time through operation.

[0095] The preset event can also be an event such as the timing device being reset and then powered on again, or the timing period being reached. When a preset event is detected, the process returns to S405 to re-determine the downlink delay Tdown. If no preset event is detected, it is determined that the distance between the timing device and the geostationary satellite has not changed, or that the timing device has not been reset. This embodiment improves the accuracy of the downlink delay Tdown by triggering the update of the downlink delay Tdown through a preset event, thereby improving the timing accuracy.

[0096] S410. Calculate the local time T1 of the time synchronization device using standard time T0, uplink delay Tup, correction parameter UTCp, and downlink delay Tdown.

[0097] Specifically, the pre-calibrated device delay Td can be obtained. The device delay Td is the time required for the timing device to resolve the time information after receiving the signal from the geostationary satellite. The local time T1 of the timing device can be calculated using the following formula:

[0098] T1 = T0 - UTCp + Tup + Tdown + Td

[0099] S411, Time synchronization is performed using local time T1.

[0100] Local time T1 is the time after the timing device is synchronized with the time of the geostationary satellite. Local time T1 is synchronized with the time of the ground control center. The timing device can use this local time T1 to provide time synchronization to its various modules or to other devices outside the timing device.

[0101] This embodiment calculates the standard time T0 and uplink delay Tup from the short message signal of the geostationary satellite, obtains the Coordinated Universal Time (UTCp) correction parameter, and directly reads the downlink delay Tdown if it is stored in the local memory of the timing device. Otherwise, it sends a timing request to the ground control center via the geostationary satellite. After receiving the timing request, the geostationary satellite forwards it to the ground control center. Upon receiving the timing request, the ground control center calculates the total one-way propagation delay Tc from the ground control center to the timing device and receives the one-way transmission from the geostationary satellite. After the total propagation delay Tc, the difference between the one-way propagation delay Tc and the uplink delay Tup is calculated as the downlink delay Tdown. The local time T1 of the timing equipment is calculated using the standard time T0, the uplink delay Tup, the correction parameter UTCp, and the downlink delay Tdown for external timing. This eliminates the need to locate the timing equipment to calculate the downlink delay and does not occupy the computing resources of the ground control center. Compared with the existing technology that calculates the delay by solving the position of the timing equipment through at least 4 satellites, this shortens the timing time, reduces the impact of the calculated position on the timing accuracy, and improves the timing speed and accuracy.

[0102] Furthermore, when the timing device is in a static state, based on the unchanged relative position between the timing device and the geostationary satellite, the downlink delay is determined by a timed request and stored in the local memory. On the one hand, the downlink delay can be directly read when the timing device is running for a long time or after a second power-on, thus improving the timing speed. On the other hand, after obtaining the downlink delay by a timed request, there is no need to request the downlink delay again, thus avoiding long-term occupation of the computing resources of the ground control center.

[0103] Furthermore, when a preset event is detected, the downlink delay is re-requested at regular intervals to avoid the problem of low timing accuracy caused by large downlink delay errors after the timing device's location changes, thus improving timing accuracy.

[0104] Example 3

[0105] Figure 5 This is a flowchart of a satellite-based timing method provided in Embodiment 3 of the present invention. This embodiment optimizes Embodiment 1 as described above. Figure 5 As shown, this satellite-based timing method includes:

[0106] S501. Receive short message signals from geostationary satellites. The short message signals include the uplink delay Tup from the ground control center to the geostationary satellite at standard time T0.

[0107] S502, Receive navigation messages from geostationary satellites and obtain the Coordinated Universal Time (UTCp) correction parameter from the navigation messages.

[0108] S501-S502 in this embodiment can refer to S201-S202 in Embodiment 1, or S401-S402 in Embodiment 2, and will not be described in detail here.

[0109] S503. Determine that the downlink delay Tdown is equal to the uplink delay Tup.

[0110] In this embodiment, since the satellite used for timing is a geostationary satellite, which is stationary relative to the Earth, the distance between the geostationary satellite and the Earth remains constant. Furthermore, the distances from the ground control center and the timing equipment to the geostationary satellite also remain constant. Figure 6 As shown, the distance from the geostationary satellite to its closest point on Earth, P3, is the satellite's altitude, H; the distance from the geostationary satellite to its farthest point on Earth, P1, is L; and the Earth's radius is R. According to the Pythagorean theorem, we can obtain:

[0111] L 2 +R 2 = (R+H) 2

[0112] The Earth's radius R = 6371 km, and the altitude of a geostationary satellite H = 35786 km. Using the above formula, we calculate L = 41672 km. The time difference between the closest point P3 and the farthest point P1 transmitted by the geostationary satellite signal is Δt = (lh) / c ≈ 19.68 ms. Generally, the ground control center is neither at the equator (closest point) nor at the farthest point. For example, the national time service center is in Xi'an. Other countries' time service centers are not located at either the closest or farthest point. Therefore, setting the downlink delay Tdown from the geostationary satellite to the time service equipment to be equal to the uplink delay Tup from the ground control center to the geostationary satellite results in an error of less than 10 ms for the downlink delay Tdown. In other words, setting the downlink delay Tdown to be equal to the uplink delay Tup can meet the needs of time service scenarios with low accuracy.

[0113] S504. Calculate the local time T1 of the time synchronization device using standard time T0, uplink delay Tup, correction parameter UTCp, and downlink delay Tdown.

[0114] Specifically, the pre-calibrated device delay Td can be obtained. This device delay Td can be the time required for the timing device to resolve the time information after receiving the signal from the geostationary satellite. The local time T1 of the timing device can then be calculated using the following formula:

[0115] T1 = T0 - UTCp + Tup + Tdown + Td

[0116] Since the downlink latency Tdown equals the uplink latency Tup, the formula for calculating local time T1 is as follows:

[0117] T1 = T0 - UTCp + 2 × Tup + Td

[0118] S505 uses local time T1 for time synchronization.

[0119] Local time T1 is the time after the timing device is synchronized with the time of the geostationary satellite. Local time T1 is synchronized with the time of the ground control center. The timing device can use this local time T1 to provide time synchronization to its various modules or to other devices outside the timing device.

[0120] In this embodiment, the timing device can receive short message signals from geostationary satellites. These short message signals include the uplink delay Tup of standard time T0 sent by the ground control center to the geostationary satellite, the navigation message received from the geostationary satellite, the Coordinated Universal Time (UTCp) correction parameter obtained from the navigation message, the determination that the downlink delay Tdown equals the uplink delay Tup, the calculation of the local time T1 of the timing device using standard time T0, uplink delay Tup, correction parameter UTCp, and downlink delay Tdown, and the external timing is then provided. The uplink delay is directly estimated as the downlink delay, eliminating the need to locate the timing device and calculate the downlink delay, and also avoiding the use of the ground control center's computing resources. Compared to existing technologies that calculate the delay after determining the location of the timing device using at least four satellites, this shortens the timing time, making it suitable for scenarios with low timing accuracy requirements. Furthermore, it eliminates the need to calculate the downlink delay, resulting in faster timing speed.

[0121] Example 4

[0122] Figure 7 This is a schematic diagram of a satellite-based timing device provided in Embodiment 4 of the present invention. Figure 7 As shown, this satellite-based timing device is applied to timing equipment and includes:

[0123] The satellite short message signal receiving module 701 is used to receive short message signals from geostationary satellites. The short message signals include the uplink delay Tup from the ground control center to the geostationary satellite at standard time T0.

[0124] The Coordinated Universal Time (UTC) correction parameter determination module 702 is used to receive navigation messages from geostationary satellites and obtain the UTC correction parameter UTCp from the navigation messages;

[0125] The downlink latency calculation module 703 is used to calculate the downlink latency Tdown from the geostationary satellite to the timing device based on the uplink latency Tup.

[0126] The local time calculation module 704 is used to calculate the local time T1 of the time synchronization device using the standard time T0, uplink delay Tup, correction parameter UTCp and downlink delay Tdown;

[0127] The time synchronization module 705 is used to synchronize time using the local time T1.

[0128] Optional, also includes:

[0129] The judgment module is used to determine whether the local memory of the timing device stores downlink delay Tdown.

[0130] The downlink latency Tdown reading module is used to read the downlink latency Tdown from the local memory of the timing device;

[0131] The jump module is used to jump to the downlink delay calculation module 703.

[0132] Optionally, the downlink latency calculation module 703 includes:

[0133] The timing request sending unit is used to send timing requests to the ground control center via the geostationary satellite. After receiving the timing request, the geostationary satellite forwards the timing request to the ground control center. When the ground control center receives the timing request, it calculates the total one-way propagation delay Tc from the ground control center to the timing equipment.

[0134] The one-way propagation total delay receiving unit is used to receive the one-way propagation total delay Tc from the geostationary satellite.

[0135] The downlink delay Tdown calculation unit is used to calculate the difference between the total one-way propagation delay Tc and the uplink delay Tup, which is used as the downlink delay Tdown.

[0136] Optionally, the following may be included after the downlink delay Tdown calculation unit:

[0137] The downlink latency Tdown storage unit is used to store the downlink latency Tdown to the local memory of the timing device.

[0138] Optionally, the downlink latency Tdown storage unit may also include:

[0139] A preset event detection unit is used to determine whether a preset event has been detected;

[0140] The adjustment unit is used to jump to the downlink delay calculation module 703.

[0141] Optionally, the downlink latency calculation module 703 includes:

[0142] The downlink delay Tdown determination unit is used to determine that the downlink delay Tdown is equal to the uplink delay Tup.

[0143] Optionally, the local time calculation module 704 includes:

[0144] The device delay Td acquisition unit is used to acquire the device delay Td;

[0145] The first calculation unit is used to calculate the difference between the standard time T0 and the correction parameter UTCp;

[0146] The second calculation unit is used to calculate the sum of the difference and the uplink delay Tup, downlink delay Tdown, and device delay Td, so as to use the local time T1 of the timing device.

[0147] The satellite-based timing device provided in the embodiments of the present invention can execute the satellite-based timing method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0148] Example 5

[0149] Figure 8 A schematic diagram of an electronic device 80 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0150] like Figure 8 As shown, the electronic device 80 includes at least one processor 81 and a memory, such as a read-only memory (ROM) 82 and a random access memory (RAM) 83, communicatively connected to the at least one processor 81. The memory stores computer programs executable by the at least one processor. The processor 81 can perform various appropriate actions and processes based on the computer program stored in the ROM 82 or loaded from storage unit 88 into the RAM 83. The RAM 83 can also store various programs and data required for the operation of the electronic device 80. The processor 81, ROM 82, and RAM 83 are interconnected via a bus 84. An input / output (I / O) interface 85 is also connected to the bus 84.

[0151] Multiple components in electronic device 80 are connected to I / O interface 85, including: input unit 86, such as keyboard, mouse, etc.; output unit 87, such as various types of monitors, speakers, etc.; storage unit 88, such as disk, optical disk, etc.; and communication unit 89, such as network card, modem, wireless transceiver, etc. Communication unit 89 allows electronic device 80 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0152] Processor 81 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 81 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 81 performs the various methods and processes described above, such as satellite-based time synchronization methods.

[0153] In some embodiments, the satellite-based timing method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 88. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 80 via ROM 82 and / or communication unit 89. When the computer program is loaded into RAM 83 and executed by processor 81, one or more steps of the satellite-based timing method described above may be performed. Alternatively, in other embodiments, processor 81 may be configured to perform the satellite-based timing method by any other suitable means (e.g., by means of firmware).

[0154] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0155] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0156] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0157] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0158] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0159] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0160] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0161] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A satellite-based time dissemination method, characterized in that, Applications in time synchronization devices include: Receive short message signals from geostationary satellites, the short message signals including the uplink delay Tup of standard time T0 sent by the ground control center to the geostationary satellite; Receive navigation messages from the geostationary satellite and obtain the Coordinated Universal Time (UTCp) correction parameter from the navigation messages; Calculate the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup. The local time T1 of the timing device is calculated using the standard time T0, the uplink delay Tup, the correction parameter UTCp, and the downlink delay Tdown; The local time T1 is used for time synchronization.

2. The satellite based time dissemination method of claim 1, wherein, Before calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup, the method further includes: Determine whether the local memory of the timing device stores the downlink delay Tdown; If so, read the downlink delay Tdown from the local memory of the timing device; If not, perform the step of calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup.

3. The satellite based time transfer method of claim 1 or 2, wherein, The calculation of the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup includes: The geostationary satellite sends a timing request to the ground control center. After receiving the timing request, the geostationary satellite forwards the timing request to the ground control center. When the ground control center receives the timing request, it calculates the total one-way propagation delay Tc from the ground control center to the timing device. The total one-way propagation delay Tc is received from the geostationary satellite; The difference between the total one-way propagation delay Tc and the uplink delay Tup is calculated and used as the downlink delay Tdown.

4. The satellite based time dissemination method of claim 3, wherein, After calculating the difference between the total one-way propagation delay Tc and the uplink delay Tup, as the downlink delay Tdown, the method further includes: The downlink delay Tdown is stored in the local memory of the timing device.

5. The satellite based time dissemination method of claim 4, wherein, After storing the downlink delay Tdown into the local memory of the timing device, the method further includes: Determine whether a preset event has been detected; If so, perform the step of calculating the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup.

6. The satellite-based time synchronization method according to claim 1, characterized in that, The calculation of the downlink delay Tdown from the geostationary satellite to the timing device based on the uplink delay Tup includes: The downlink delay Tdown is determined to be equal to the uplink delay Tup.

7. The satellite-based time synchronization method according to claim 1, characterized in that, The calculation of the local time T1 of the timing device using the standard time T0, the uplink delay Tup, the correction parameter UTCp, and the downlink delay Tdown includes: Obtain device latency Td; Calculate the difference between the standard time T0 and the correction parameter UTCp; The sum of the difference, the uplink delay Tup, the downlink delay Tdown, and the device delay Td is calculated to serve as the local time T1 of the timing device.

8. A satellite-based timing device, characterized in that, Applications in time synchronization devices include: The satellite short message signal receiving module is used to receive short message signals from geostationary satellites. The short message signals include the uplink delay Tup of the standard time T0 sent by the ground control center to the geostationary satellite. The Coordinated Universal Time Correction Parameter Determination Module is used to receive the navigation message from the geostationary satellite and obtain the Coordinated Universal Time Correction Parameter UTCp from the navigation message; The downlink latency calculation module is used to calculate the downlink latency Tdown from the geostationary satellite to the timing device based on the uplink latency Tup. The local time calculation module is used to calculate the local time T1 of the time synchronization device using the standard time T0, the uplink delay Tup, the correction parameter UTCp, and the downlink delay Tdown; The time synchronization module is used to synchronize the local time T1.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the satellite-based timing method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the satellite-based timing method according to any one of claims 1-7.

Images