Satellite-ground time difference monitoring method, system, product and equipment based on ground station and narrowband communication terminal, and storage medium

Abstract

The invention discloses a satellite-ground time difference monitoring method, system, product and equipment based on a ground station and a narrow-band communication terminal and a storage medium, belongs to the technical field of remote sensing satellite measurement and control, and solves the problems of data loss, orbit measurement and calculation misalignment and imaging position offset caused by the fact that satellite-ground time difference cannot be obtained in time in the prior art. And the ground station is limited in receiving range and poor in timeliness. The method comprises the following steps: 1, acquiring satellite telemetry by using a ground station or a ground narrowband communication terminal; 2, carrying out system conversion on satellite telemetering and ground time respectively; and step 3, obtaining the satellite-ground time difference based on the satellite telemetry after the system conversion and the ground time after the system conversion. The satellite-ground time difference monitoring method is used for realizing real-time and accurate satellite-ground time difference monitoring.

Description

Technical Field

[0001] This invention relates to the field of remote sensing satellite telemetry and control technology, specifically to a satellite-to-ground time difference monitoring method based on ground stations and narrowband communication terminals. Background Technology

[0002] Precise time is a prerequisite for efficient collaboration between satellites and between satellites and the ground, and is the cornerstone of normal satellite operation and payload utilization. However, satellites operate in the complex space environment. On the one hand, factors such as temperature and radiation can degrade the performance of the satellite's crystal oscillators, causing clock drift and resulting in inaccurate time. On the other hand, external human interference can affect the operation and management of remote sensing constellations, making it difficult for the satellite's time system to distinguish between correct and incorrect time. In addition, there is a small probability that the satellite itself may experience time system failure. These situations do not meet the requirements for normal satellite operation and payload utilization, and may lead to a chain reaction of data loss, inaccurate orbit calculations, and imaging position deviations. Therefore, ground monitoring is necessary. Using a stable and reliable ground time as a reference, the time difference between the satellite and the ground is measured to obtain an accurate satellite-to-ground time difference. This allows for the establishment of a satellite-to-ground time difference monitoring model, enabling users to obtain timely satellite-to-ground time difference information and take appropriate action.

[0003] In the prior art, Chinese patent document CN118573259A discloses "a method, system, device, electronic device, and medium for measuring satellite-to-ground time difference." In this method, a ground station sends uplink measurement frames to a low-Earth orbit (LEO) satellite, which samples these frames to obtain on-board measurement information. The ground station then receives downlink measurement frames from the LEO satellite, which contain on-board measurement information, and samples the uplink frames to obtain ground uplink measurement information. The ground station then extracts the on-board measurement information from the downlink frames and determines the satellite-to-ground time difference based on the on-board and ground uplink measurement information. However, this technical solution relies solely on the ground station to acquire measurement information. The ground station has a small receiving range, and the satellite rarely enters its receiving range. Even when the satellite enters its receiving range, the ground station may be performing other tasks and lack available antenna resources to track the target satellite, thus hindering the timely transmission and reception of measurement frames and reducing the timeliness of satellite-to-ground time difference measurement.

[0004] In summary, existing technologies suffer from technical problems such as inaccurate satellite orbit calculations, imaging position shifts, and data loss due to the limited receiving range and poor timeliness of ground stations, which prevent timely acquisition of satellite-to-ground time differences and determination of whether satellite and ground times are consistent. Summary of the Invention

[0005] This invention solves the technical problems in the prior art where the limited receiving range and poor timeliness of ground stations make it impossible to obtain the satellite-to-ground time difference and determine whether the satellite-to-ground time is consistent, which may lead to inaccurate satellite orbit calculation, imaging position offset, and loss of downlink data.

[0006] The present invention discloses a satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal, comprising the following steps: Step 1: Obtain satellite telemetry data using a ground station or a ground narrowband communication terminal; Step 2: Convert the satellite telemetry and ground time into different number systems respectively; Step 3: Based on the satellite telemetry data after conversion and the ground time data after conversion, obtain the satellite-to-ground time difference.

[0007] Furthermore, in one embodiment of the present invention, the satellite telemetry includes integer seconds and fractional seconds, the ground time includes accumulated days and accumulated seconds, and the number system conversion is to convert hexadecimal to decimal.

[0008] Furthermore, in one embodiment of the present invention, when acquiring satellite telemetry data through a ground station, a data frame header containing ground time stamps is added to the source code of the satellite telemetry data.

[0009] Furthermore, in one embodiment of the present invention, when the satellite telemetry is acquired through a ground narrowband communication terminal, the ground time at the time of reception is recorded together with the satellite telemetry in its original form of Y year M month D day h hour m minute s second μ microsecond.

[0010] Furthermore, in one embodiment of the present invention, the satellite-to-ground time difference is calculated based on satellite telemetry acquired by the ground station, specifically as follows: ; in, The satellite-to-ground time difference is based on the data obtained from the ground station. and These are the integer seconds and fractional seconds after base conversion, respectively. and These are the accumulated days and seconds after conversion between number systems.

[0011] Furthermore, in one embodiment of the present invention, the satellite-to-ground time difference is calculated based on satellite telemetry acquired by a terrestrial narrowband communication terminal, specifically as follows: ; in, N represents the satellite-to-ground time difference obtained based on the terrestrial narrowband communication terminal, and N is the cumulative number of days from January 1, 2000 to D day of M month, Y year.

[0012] The present invention discloses a satellite-to-ground time difference monitoring system based on a ground station and a narrowband communication terminal. The system is constructed based on the above method and includes the following modules: Module 1 acquires satellite telemetry data using a ground station or a ground narrowband communication terminal; Module 2 performs number system conversions for satellite telemetry and ground time. Module 3 calculates the satellite-to-ground time difference based on the converted satellite telemetry data and the converted ground time data.

[0013] The computer program product of the present invention includes a computer program or instructions, which, when executed by a processor, implement any of the above-described methods for monitoring the time difference between satellite and ground stations based on ground stations and narrowband communication terminals.

[0014] The electronic device of the present invention includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus. Memory, used to store computer programs; The processor, when executing the program stored in the memory, implements any of the above-described methods for monitoring the time difference between satellite and ground stations based on ground stations and narrowband communication terminals.

[0015] The present invention provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, which, when executed by a processor, implements any of the above-described methods for monitoring the time difference between satellite and ground stations based on ground stations and narrowband communication terminals.

[0016] This invention solves the technical problems of existing technologies, such as the inability to obtain satellite-to-ground time difference and determine whether satellite and ground times are consistent due to the limited receiving range and poor timeliness of ground stations. This can lead to inaccurate satellite orbit calculations, imaging position offsets, and data loss during downlink transmission. Specific beneficial effects include: This invention proposes a satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal. By establishing a joint monitoring system using a ground station and a narrowband communication terminal, the method avoids the problems of limited reception range and poor timeliness that can occur when using only a ground station. It obtains accurate satellite-to-ground time difference information, allowing users to promptly receive satellite-to-ground time difference information, thereby detecting and handling anomalies. This avoids inaccurate satellite orbit calculations, imaging position shifts, and data loss during downlink transmission. It provides a decision-making basis for subsequent satellite-to-ground time difference correction research and promotes the development of aerospace technology. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1This is a flowchart of the satellite-to-ground time difference monitoring method based on ground stations and narrowband communication terminals as described in Implementation Method 1; Figure 2 This is a diagram of the ground station receiving telemetry data structure as described in Implementation Method 3. Detailed Implementation

[0018] Various embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. The embodiments described with reference to the drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0019] Implementation Method 1: A satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal, comprising the following steps: Step 1: Obtain satellite telemetry data using a ground station or a ground narrowband communication terminal; Step 2: Convert the satellite telemetry and ground time into different number systems respectively; Step 3: Based on the satellite telemetry data after conversion and the ground time data after conversion, obtain the satellite-to-ground time difference.

[0020] Existing technologies in satellite communication and remote sensing suffer from the physical limitation of limited coverage of ground stations, making it impossible to obtain accurate and timely satellite-to-ground time differences. This leads to the inability to detect anomalies in satellite time in a timely manner, which may cause a series of chain reactions, such as inaccurate satellite orbit calculations, imaging position shifts, and loss of downlink data.

[0021] To address the aforementioned issues, this implementation method establishes a satellite-to-ground time difference monitoring model to obtain accurate satellite-to-ground time differences, such as... Figure 1 As shown, satellite telemetry is acquired and analyzed through both ground stations and narrowband communication to obtain satellite time and calculate the satellite-to-ground time difference, and the relevant data is stored. When the satellite passes within the receiving range of the ground station, a satellite tracking plan can be issued to the ground station to receive satellite telemetry. When the satellite is outside the receiving range of the ground station but within the narrowband communication telemetry and control range, the ground terminal continuously receives telemetry transmitted by the satellite via narrowband communication. Satellite time can be obtained from the satellite telemetry acquired through both methods, and the satellite-to-ground time difference can be calculated by comparing it with ground time, thereby establishing a satellite-to-ground time difference monitoring model.

[0022] Implementation Method 2: This implementation method further defines the satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal described in Implementation Method 1. The satellite telemetry includes integer seconds and fractional seconds, the ground time includes accumulated days and accumulated seconds, and the number system conversion is to convert hexadecimal to decimal.

[0023] In telemetry, on-board time is stored in two fields: integer seconds and fractional seconds. The integer seconds field is 4 bytes long and is a hexadecimal representation of the cumulative seconds count from 20:00 Beijing time on January 1, 2000, to the time the telemetry frame was generated. The fractional seconds field is 3 bytes long and is a hexadecimal representation of the fractional seconds of the telemetry frame's generation time. The hexadecimal source code is denoted as... , Total Bit, express Counting from right to left 16-bit hexadecimal code The corresponding decimal value is... The decimal value represented Equation (1) yields: (1) The integer and fractional seconds on the satellite are converted from hexadecimal to decimal using equation (1), and are denoted as follows: and .

[0024] Regarding ground time, for ground stations, ground time is divided into two fields: accumulated days and accumulated seconds. The accumulated days field is 2 bytes long and is a hexadecimal representation of the cumulative number of days from January 1, 2000 (Beijing time) until the ground receives the telemetry frame. The accumulated seconds field is 4 bytes long and is a hexadecimal representation of the cumulative time from 0:00 Beijing time on that day until the ground receives the telemetry frame, counted in units of 100 microseconds (i.e., 0.1 milliseconds). The accumulated days and seconds are converted from hexadecimal to decimal using equation (1), and are denoted as follows: and .

[0025] Table 1 summarizes the characteristics of the satellite integer seconds, fractional seconds, and ground area days and accumulated seconds fields.

[0026] Table 1

[0027] The positions of the integer seconds and fractional seconds fields on satellites may differ for different satellite models; the positions of the day and second fields in the ground data frame header may also differ for different ground stations, and need to be extracted according to the corresponding protocol.

[0028] Implementation Method 3: This implementation method further defines the satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal described in Implementation Method 1. When acquiring satellite telemetry data through the ground station, a data frame header containing a ground time stamp is added to the satellite telemetry source code.

[0029] like Figure 2As shown, when the ground station receives telemetry data from the satellite, it adds a data frame header containing ground time stamps to the telemetry source code. This is for the satellite-to-ground time difference between the satellite and the ground station. (Unit: seconds), the difference in cumulative time between satellite and ground needs to be calculated based on the same starting time. Taking 00:00 on January 1, 2000 as the base, it can be calculated using formula (2): (2) in, The satellite-to-ground time difference is based on the data obtained from the ground station. and These are the integer seconds and fractional seconds after base conversion, respectively. and These are the accumulated days and seconds after conversion between number systems.

[0030] Implementation Method 4: This implementation method further defines the satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal described in Implementation Method 1. When the satellite telemetry is acquired through the ground narrowband communication terminal, the ground time at the time of reception is recorded together with the satellite telemetry in the original form of Y year M month D day h hour m minute s second μ microsecond.

[0031] Considering the limited reception range of ground stations, which may affect timeliness, this implementation method uses a ground narrowband communication terminal to acquire satellite telemetry. When the satellite is outside the reception range of the ground station, the ground narrowband communication terminal can also be used to calculate the satellite-to-ground time difference, which is highly responsive and avoids the inability to obtain the satellite-to-ground time difference in a timely manner.

[0032] Chinese patent document CN113346939A discloses a "satellite command uploading system and method with narrowband communication and information forwarding functions", which can be used to receive satellite telemetry using terrestrial narrowband communication.

[0033] In this embodiment, when a ground-based narrowband communication terminal receives telemetry data from a satellite, the reception time is recorded in its original form, such as Y year M month D day h hour m minute s second μ microsecond.

[0034] For the satellite-to-ground time difference between satellite and ground narrowband communication terminals (Unit: seconds), the difference in cumulative time between satellite and ground needs to be calculated based on the same starting time. Taking 00:00 on January 1, 2000 as the base, it can be calculated using formula (3): (3) in, N represents the satellite-to-ground time difference obtained based on the terrestrial narrowband communication terminal, and N is the cumulative number of days from January 1, 2000 to D day of M month, Y year.

[0035] Furthermore, in this embodiment, since there are a large number of on-board telemetry frames with microsecond-level time, storing each frame as a file would have low utilization. Therefore, this embodiment stores the satellite telemetry source code as a single file within each continuous arc segment of the satellite.

[0036] Furthermore, in this embodiment, since there are a large number of on-board telemetry frames with microsecond-level time, the utilization rate of storing the satellite-to-ground time difference calculated for each frame as a row record in the database is low. In this embodiment, when storing the satellite-to-ground time difference data in the database, the satellite-to-ground time difference within a continuous arc segment of each satellite is averaged, and only the average result is stored as a row record in the database.

[0037] Implementation Method 5: This implementation method describes a satellite-to-ground time difference monitoring system based on a ground station and a narrowband communication terminal. The system is constructed based on the method described in Implementation Method 1 and includes the following modules: Module 1 acquires satellite telemetry data using a ground station or a ground narrowband communication terminal; Module 2 performs number system conversions for satellite telemetry and ground time. Module 3 calculates the satellite-to-ground time difference based on the converted satellite telemetry data and the converted ground time data.

[0038] Implementation Method Six: A computer program product described in this implementation method includes a computer program or instructions, which, when executed by a processor, implement the satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal as described in any of the above implementation methods.

[0039] Implementation Method Seven: An electronic device according to this implementation method includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus. Memory, used to store computer programs; When the processor executes the program stored in the memory, it implements the satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal as described in any of the above embodiments.

[0040] Implementation Method 8: A computer-readable storage medium according to this implementation method, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal as described in any of the above implementation methods.

[0041] Currently, the system has initially established an emergency telemetry and control service architecture for some satellite models and completed the construction of a prototype system. Extensive testing has been conducted on a group of satellites in orbit, and the results are good and meet the expected standards.

[0042] The foregoing has provided a detailed description of the satellite-to-ground time difference monitoring method, system, product, equipment, and storage medium based on a ground station and narrowband communication terminal proposed in this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for monitoring satellite-to-ground time difference based on a ground station and a narrowband communication terminal, characterized in that, Includes the following steps: Step 1: Obtain satellite telemetry data using a ground station or a ground narrowband communication terminal; Step 2: Convert the satellite telemetry and ground time into different number systems respectively; Step 3: Based on the satellite telemetry data after conversion and the ground time data after conversion, obtain the satellite-to-ground time difference.

2. The satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal according to claim 1, characterized in that, The satellite telemetry includes integer seconds and fractional seconds, the ground time includes accumulated days and accumulated seconds, and the number system conversion is to convert hexadecimal to decimal.

3. The satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal according to claim 2, characterized in that, When acquiring satellite telemetry data via ground stations, a data frame header containing ground time stamps is added to the satellite telemetry source code.

4. The satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal according to claim 2, characterized in that, When the satellite telemetry is acquired through a ground narrowband communication terminal, the ground time at the time of reception is recorded together with the satellite telemetry in its original form as Y year M month D day h hour m minute s second μ microsecond.

5. The satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal according to claim 3, characterized in that, Based on satellite telemetry data obtained from ground stations, the satellite-to-ground time difference is calculated as follows: ； in, The satellite-to-ground time difference is based on the data obtained from the ground station. and These are the integer seconds and fractional seconds after base conversion, respectively. and These are the accumulated days and seconds after conversion between number systems.

6. The satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal according to claim 4, characterized in that, Based on satellite telemetry acquired from a ground-based narrowband communication terminal, the satellite-to-ground time difference is calculated as follows: ； in, N represents the satellite-to-ground time difference obtained based on the terrestrial narrowband communication terminal, and N is the cumulative number of days from January 1, 2000 to D day of M month, Y year.

7. A satellite-to-ground time difference monitoring system based on a ground station and a narrowband communication terminal, the system being constructed based on the method described in claim 1, characterized in that... Includes the following modules: Module 1 acquires satellite telemetry data using a ground station or a ground narrowband communication terminal; Module 2 performs number system conversions for satellite telemetry and ground time. Module 3 calculates the satellite-to-ground time difference based on the converted satellite telemetry data and the converted ground time data.

8. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by the processor, they implement the satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal as described in any one of claims 1-6.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; The processor, when executing a program stored in memory, implements the satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal as described in any one of claims 1-6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the satellite-to-ground time difference monitoring method based on a ground station and a narrowband communication terminal as described in any one of claims 1-6.

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