Method, device and equipment for determining measurement and control orbit of low-orbit satellite and medium

Abstract

The invention discloses a low-orbit satellite measurement and control orbit determination method, device and equipment and a medium, and the method comprises the steps: obtaining a satellite-borne GNSS pseudo-range observation value and a GNSS broadcast ephemeris, and carrying out the calculation through a pseudo-range single-point positioning algorithm, and obtaining a self-positioning result of a low-orbit satellite; when the number of GNSS satellites used by pseudo-range single-point positioning is lower than a first threshold value, or a satellite space distribution characteristic value of a positioning epoch is greater than a second threshold value, removing a corresponding self-positioning result; polynomial fitting is carried out on the filtered self-positioning results by adopting a sliding window, the self-positioning results with fitting residual errors larger than a third threshold value are removed, then interpolation processing is carried out, and optimized self-positioning results are obtained; and orbit determination is carried out in combination with a dynamic fitting method, and a final low-orbit satellite measurement and control orbit is obtained. The method is low in calculation cost and good in real-time performance, gets rid of the dependence of a ground station, is less affected by low-orbit satellite orbit maneuver, and can reflect a more accurate satellite position.

Description

Technical Field

[0001] The present invention relates to the field of satellite orbit measurement and control technology, and in particular to a method, device, equipment and medium for determining a low-orbit satellite measurement and control orbit. Background Art

[0002] Orbit measurement and control of low-orbit satellites is crucial to ensure the normal operation of satellites and the execution of missions. Accurate orbit determination can provide precise position and velocity information of satellites, thereby supporting effective attitude control, orbit correction, and collision avoidance operations. In addition, orbit measurement and control can also ensure smooth communication between satellites and ground stations, helping the smooth implementation of scientific research, remote sensing observation, navigation and positioning tasks.

[0003] The orbit of a low-orbit satellite is affected by a variety of disturbance factors, such as atmospheric drag and solar radiation pressure. Traditional orbit measurement and control methods, such as ground station observations or onboard GNSS (Global Navigation Satellite System) observations, usually find it difficult to provide high-precision orbit status in a short period of time. Onboard self-positioning data can provide instant orbit information, which does not rely on real-time observation data from ground measurement and control stations, reducing the impact of data transmission delays. Through onboard reception and autonomous navigation and positioning algorithms, satellites can complete orbit determination without ground control, which can effectively alleviate the shortcomings of relying on ground stations. It helps to reduce operation and maintenance costs and improve the efficiency of orbit determination, especially for high-frequency low-orbit satellite monitoring tasks, and can achieve a lower-cost orbit measurement and control solution. Up to now, there has been little research on low-orbit satellite measurement and control orbit determination based on onboard self-positioning data. In the prior art, the following technical methods are highly relevant to this method: The patent application with publication number CN117008155A discloses a method for improving the orbit accuracy of single-point positioning of low-orbit satellites in orbit. According to the position and velocity time series transmitted by the low-orbit satellite in a period of time, the six Kepler roots of the low-orbit satellite at the initial moment are calculated, and two custom coefficients and pseudo-random pulse parameters within N time periods are fitted. On this basis, the acceleration of the low-orbit satellite is integrated using the Collocation multi-step method, and the dynamic smoothed orbit of the low-orbit satellite at any time in the integration interval is obtained using the integrated data, so as to realize low-cost precise orbit determination of low-orbit satellites. However, the implementation process of this scheme is relatively complicated, and the entire orbit determination arc needs to be segmented. Moreover, it is necessary to perform least squares fitting first to obtain two custom coefficients, and the calculation process is complicated and time-consuming. The two custom coefficients represent the tangential and normal accelerations of the solar pressure respectively, and the solar pressure perturbation effect on the low-orbit satellite is not significant. Atmospheric drag is the largest error source of the perturbation force on the low-orbit satellite. This scheme does not consider the improvement of atmospheric drag, and there may be large orbit errors.

[0004] The patent application with publication number CN113008243A discloses a method and system for autonomous orbit determination of a low-orbit satellite constellation, including obtaining inter-satellite link ranging data and onboard GNSS receiver observation data. First, the onboard observation data is used to perform PPP solution to obtain the rough position of the low-orbit satellite, and then the low-orbit satellite orbit is fitted based on dynamics. Finally, the low-orbit constellation network is jointly adjusted through the inter-satellite link data to achieve high-precision, safe and autonomous orbit determination on the low-orbit satellite. However, this method contains multiple key steps, and the required data types and data volumes are relatively large. It is necessary to use both the precise single-point positioning method and the dynamic orbit determination method. The implementation process is cumbersome and the calculation is large.

[0005] The patent application with publication number CN110058287A discloses a method, device and system for determining the orbit of a low-orbit satellite. The method obtains the orbit and clock error of a navigation satellite based on broadcast ephemeris calculations, introduces correction information of positioning information from the ground system, and uses accurate corrected positioning information to determine the orbit of the low-orbit satellite, thereby improving the orbit determination accuracy of the low-orbit satellite. However, it is not easy to obtain correction information of the navigation satellite through the ground system in this method, and the accuracy of the navigation satellite orbit calculated by combining the broadcast ephemeris and correction information cannot be guaranteed, resulting in limited accuracy of low-orbit satellite orbit determination. This method relies on both navigation satellites and ground stations, and has poor autonomy.

[0006] Therefore, the prior art mainly has the following technical problems: (1) Traditional orbit measurement and control methods such as ground station observation or satellite-borne GNSS observation are usually difficult to provide high-precision orbit status in a short period of time. Low-orbit satellite orbit determination through ground station observation and satellite-borne GNSS observation generally requires a relatively precise dynamic model. In addition, the dynamic orbit determination method needs to ensure real-time observation data transmission and requires strict data processing algorithms from the ground station. The implementation process is computationally intensive and relatively complex. (2) During the orbit control process of low-orbit satellites, the attitude and orbit of the satellite will change frequently, which will reduce the timeliness and accuracy of onboard or ground observation data. The dynamic changes of the satellite may cause observation data deviation, thus affecting the orbit determination accuracy. The use of orbit control acceleration modeling will inevitably increase the computational complexity and increase the computational time. How to achieve orbit determination of low-orbit satellites during orbit control becomes a difficult problem. (3) Since the satellite cannot implement overly complex algorithms, the onboard self-positioning results are generally obtained by solving a simple single-point positioning algorithm. Due to the high dynamic motion of low-orbit satellites and the quality of onboard observation data, there may be outliers in the onboard self-positioning data, which seriously deviate from the actual orbit of the low-orbit satellite. In addition, the onboard self-positioning data of low-orbit satellites are discrete points with unequal intervals, which do not conform to the smooth orbit characteristics of low-orbit satellites. Direct use for orbit determination may lead to orbit fitting divergence. Summary of the invention

[0007] In view of the deficiencies in the prior art, an object of the present invention is to provide a method, device, equipment and medium for determining a low-orbit satellite tracking and control orbit, so as to solve at least one of the above-mentioned technical problems.

[0008] In a first aspect, a method for determining a low-orbit satellite tracking and control orbit is provided, comprising the following steps: Obtain self-positioning results: Obtain onboard GNSS pseudo-range observations and GNSS broadcast ephemeris, and obtain the self-positioning results of low-orbit satellites through pseudo-range single-point positioning algorithm; Self-positioning result filtering: When the number of GNSS satellites used for pseudo-range single-point positioning is lower than the first threshold, the corresponding self-positioning result is discarded; the satellite spatial distribution characteristic value of the positioning epoch is calculated, and when the satellite spatial distribution characteristic value is greater than the second threshold, the corresponding self-positioning result is discarded; Self-positioning result optimization: The filtered self-positioning results are fitted with a polynomial using a sliding window method, and the self-positioning results with fitting residuals greater than the third threshold are eliminated. Interpolation processing is performed based on the final fitted polynomial to obtain the optimized self-positioning results. Satellite orbit determination: Based on the optimized self-positioning results, the low-orbit satellite is orbit determined using the dynamic fitting method to obtain the final low-orbit satellite tracking and control orbit.

[0009] Furthermore, the self-positioning result of the low-orbit satellite is obtained by solving the pseudo-range single-point positioning algorithm, specifically including: Spaceborne GNSS pseudorange observations The observation equation is expressed as follows: ; In the formula, the subscript , Represent the frequency and satellite receiver respectively, the superscript represents a GNSS satellite, Indicates the geometric distance from the GNSS satellite to the center of the onboard receiver; and They represent the receiver clock error and satellite clock error contained in the pseudorange respectively; and Respectively represent the frequency The hardware delay deviation between the receiver and the satellite, where the hardware delay at the receiver is received by the receiver clock error during positioning; represents the tropospheric delay error of pseudorange measurement, Indicates frequency The ionospheric delay, is the pseudorange observation noise, is the speed of light in a vacuum; The error equation after linearization of the observation equation of the satellite-borne GNSS pseudorange observation value is expressed as follows: ; In the formula, is the observation correction vector, is the design matrix, is the residual vector of pseudorange observations, is the unknown parameter correction vector, ,in , , is the satellite receiver coordinate correction number; The unknown parameter correction vector can be obtained by the least squares principle: ; In the formula, is the coefficient matrix of the normal equation, is the observation value weight matrix; Iterative calculation is performed until the unknown parameter correction vector meets the iterative convergence condition, and then the coordinates of the onboard receiver at the current epoch are obtained as the self-positioning result of the low-orbit satellite.

[0010] Furthermore, the satellite spatial distribution characteristic value is calculated by the following method: The geometric distance from the GNSS satellite to the center of the onboard receiver Approximate position of satellite in low orbit Perform Taylor series expansion at , retain the first-order term, and the linearized equation is: ; In the formula, , , , is the geometric distance from the GNSS satellite to the center of the onboard receiver calculated from the approximate position, Indicates GNSS satellite coordinates; make ,have , subscript n is the number of GNSS satellites observed by the onboard receiver in the current epoch; Then the satellite spatial distribution characteristic value is .

[0011] Furthermore, the self-positioning result optimization specifically includes: Set the sliding window length and sliding step size. The sliding window length is equal to the sliding step size. Divide the filtered self-positioning results into multiple segments of self-positioning results through a sliding window; For each segment of the self-positioning results after division, a polynomial fitting is performed, and the self-positioning results whose fitting residuals are greater than the third threshold are eliminated. The polynomial fitting and elimination process is iterated until the fitting residuals of the retained self-positioning results are all less than the third threshold, thereby obtaining the final fitting polynomial; Interpolation processing is performed according to the final fitted polynomial to obtain the optimized self-positioning result.

[0012] Furthermore, the satellite orbit determination specifically includes: Assumptions The self-positioning position on the satellite at time ; The position and velocity at the initial orbit time can be obtained by fitting the final fitting polynomial, and the position and velocity at the initial orbit time can be obtained by integration. The low-orbit satellite position at the time , and then establish the N-dimensional observation equation as follows: = ; In the formula, for The satellite motion state transfer matrix at time , , , are the corrections of the position, velocity and dynamic parameters of the low-orbit satellite at the time of initial orbit; Find the least squares optimal solution for the N-dimensional observation equation and perform iterative calculation until , , The iterative convergence conditions are met, and then the final orbit of the low-orbit satellite is obtained through orbit integration.

[0013] Furthermore, the first threshold is 8; the second threshold is 2; and the third threshold is 10m.

[0014] In a second aspect, a low-orbit satellite tracking and control orbit determination device is provided, comprising: The initial self-positioning module is used to obtain the onboard GNSS pseudo-range observation values ​​and GNSS broadcast ephemeris, and obtain the self-positioning result of the low-orbit satellite through the pseudo-range single-point positioning algorithm; A filtering module is used to remove the corresponding self-positioning result when the number of GNSS satellites used for pseudo-range single-point positioning is lower than a first threshold; calculate the satellite spatial distribution characteristic value of the positioning epoch, and when the satellite spatial distribution characteristic value is greater than a second threshold, remove the corresponding self-positioning result; An optimization module is used to perform polynomial fitting on the filtered self-positioning results by using a sliding window method, eliminate the self-positioning results whose fitting residuals are greater than a third threshold, and perform interpolation processing according to the final fitted polynomial to obtain an optimized self-positioning result; The orbit determination module is used to determine the orbit of the low-orbit satellite using the dynamic fitting method based on the optimized self-positioning results to obtain the final low-orbit satellite measurement and control orbit.

[0015] In a third aspect, a low-orbit satellite tracking and control orbit determination device is provided, which is configured on a low-orbit satellite and includes: The onboard receiver is used to receive onboard GNSS pseudorange observations and GNSS broadcast ephemeris and transmit them to the low-orbit satellite orbit determination module; The satellite-side computing module is configured to implement the low-orbit satellite tracking and control orbit determination method as described above.

[0016] In a fourth aspect, an electronic device is provided, including: Memory on which computer programs or instructions are stored; The processor is used to load and execute the computer program or instructions to implement the low-orbit satellite tracking and control orbit determination method as described above.

[0017] In a fifth aspect, a computer-readable storage medium is provided, on which a computer program or instruction is stored. When the computer program or instruction is executed by a processor, the method for determining the low-orbit satellite tracking and control orbit as described above is implemented.

[0018] The present invention proposes a method, device, equipment and medium for determining a low-orbit satellite tracking and control orbit, which has the following beneficial effects: (1) In order to solve the problem of large errors in ground-based observation data during orbit control, it is proposed to use the GNSS observation data and GNSS broadcast ephemeris received by the onboard receiver to perform pseudo-range single-point positioning and solve the preliminary low-orbit satellite self-positioning in real time, which can achieve relatively accurate orbit determination during orbit control; (2) As for the problem of some outliers in the onboard self-positioning results, it is proposed to use the satellite spatial distribution characteristic values ​​and the number of satellites used in the self-positioning solution to eliminate the outliers in the self-positioning results, thereby improving the quality of the original self-positioning data from the positioning principle; (3) The short-term low-orbit satellite orbit conforms to the polynomial characteristics. In order to make the discrete on-board self-positioning results better used for dynamic orbit determination, it is proposed to use the sliding window polynomial fitting method to fit and smooth the self-positioning data, and further eliminate the outliers in the self-positioning results through the fitting residual. The smoothed self-positioning data can effectively improve the orbit determination accuracy. (4) The implementation process of the present invention is relatively simple. The pseudo-range single-point positioning algorithm is used to reduce the computational complexity. Only pseudo-range measurement data is used, which also reduces the data processing complexity and the amount of calculation. Therefore, the overall computational cost is low and has good real-time performance. It can realize the measurement and control orbit determination of low-orbit satellites without relying on ground stations. Since the self-positioning result is solved in real time, it is less affected by the orbital maneuvers of low-orbit satellites and can reflect a more accurate satellite position. The measurement and control tasks of a large number of low-orbit satellites in a large low-orbit constellation are arduous and complex, and low-orbit satellites have frequent orbital maneuvers. The present invention provides a solution to the measurement and control orbit determination problem of low-orbit satellites under this situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a flow chart of a method for determining a low-orbit satellite tracking and control orbit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0022] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or order. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0023] like Figure 1 As shown, an embodiment of the present invention provides a method for determining a low-orbit satellite tracking and control orbit, comprising the following steps: S1: Obtain self-positioning results: Obtain the onboard GNSS pseudo-range observation values ​​and GNSS broadcast ephemeris, and obtain the self-positioning results of the low-orbit satellite through the pseudo-range single-point positioning algorithm.

[0024] Specifically, the pseudo-range single point positioning algorithm includes the following processes: Spaceborne GNSS pseudorange observations The observation equation is expressed as follows: ; In the formula, the subscript , Represent the frequency and satellite receiver respectively, the superscript represents a GNSS satellite, Indicates the geometric distance from the GNSS satellite to the center of the onboard receiver; and They represent the receiver clock error and satellite clock error contained in the pseudorange respectively; and Respectively represent the frequency The hardware delay deviation between the receiver and the satellite, where the hardware delay at the receiver is received by the receiver clock error during positioning; represents the tropospheric delay error of pseudorange measurement, Indicates frequency The ionospheric delay, is the pseudorange observation noise, is the speed of light in a vacuum; The geometric distance from the GNSS satellite to the center of the onboard receiver , where are the GNSS satellite coordinates, is the center coordinate of the satellite receiver; the center coordinate of the satellite receiver is the quantity to be solved. In the initial calculation, the center coordinate of the satellite receiver uses the approximate position Instead, the coordinate correction number of the satellite receiver is continuously optimized to obtain the final satellite receiver center coordinate position as the low-orbit satellite self-positioning result; the process of optimizing the satellite receiver coordinate correction number is as follows: The error equation after linearization of the observation equation of the satellite-borne GNSS pseudorange observation value is expressed as follows: ; In the formula, is the vector of observation corrections; is the design matrix; is the residual vector of pseudorange observations, is the pseudorange observations minus the geometric distance The residual vector after summing up the errors; is the unknown parameter correction vector, ,in , , is the satellite receiver coordinate correction number; The unknown parameter correction vector can be obtained by the least squares principle: ; In the formula, is the coefficient matrix of the normal equation, is the observation value weight matrix; Iterative calculation is performed until the unknown parameter correction vector meets the iterative convergence condition, and then the coordinates of the onboard receiver at the current epoch are obtained as the self-positioning result of the low-orbit satellite.

[0025] To address the problem of large errors in ground-based observation data during orbit control, it is proposed to use the GNSS observation data and GNSS broadcast ephemeris received by the onboard receiver to perform pseudo-range single-point positioning and solve the preliminary low-orbit satellite self-positioning in real time, which can achieve relatively accurate orbit determination during orbit control.

[0026] S2: Self-positioning result filtering: When the number of GNSS satellites used for pseudo-range single-point positioning is lower than the first threshold, the corresponding self-positioning result is discarded; the satellite spatial distribution characteristic value of the positioning epoch is calculated, and when the satellite spatial distribution characteristic value is greater than the second threshold, the corresponding self-positioning result is discarded.

[0027] Through step S1, the center coordinates of the satellite receiver at multiple epochs (i.e., the self-positioning results of low-orbit satellites) can be obtained. However, due to the high dynamic operation of low-orbit satellites, the number of GNSS satellites observed by the satellite receiver in some periods is too small or the spatial distribution configuration is poor, which will cause a large deviation in the center coordinates of the satellite receiver obtained in step S1. To address this problem, two strategies are used in this embodiment to filter the self-positioning results of low-orbit satellites over a period of time: the first strategy is to eliminate the self-positioning results when the number of GNSS satellites used for pseudo-range single-point positioning is lower than the first threshold; the second strategy is to calculate the satellite spatial distribution characteristic value of the positioning epoch, and eliminate the self-positioning result when the satellite spatial distribution characteristic value is greater than the second threshold. The above-mentioned first threshold and second threshold are set according to empirical values. In this embodiment, the first threshold is 8; the second threshold is 2, so as to ensure the accuracy of the self-positioning results of low-orbit satellites with high dynamic operation.

[0028] The smaller the satellite spatial distribution characteristic value is, the higher the on-board self-positioning accuracy of the low-orbit satellite is, which is calculated by the following method: The geometric distance from the GNSS satellite to the center of the onboard receiver Approximate position of satellite in low orbit Perform Taylor series expansion at , retain the first-order term, and the linearized equation is: ; In the formula, , , , is the geometric distance from the GNSS satellite to the center of the onboard receiver calculated from the approximate position, Indicates GNSS satellite coordinates; make ,have , subscript n is the number of GNSS satellites observed by the onboard receiver in the current epoch; Then the satellite spatial distribution characteristic value is .

[0029] To solve the problem of some outliers in the onboard self-positioning results, it is proposed to eliminate the outliers in the self-positioning results by using the satellite spatial distribution characteristic values ​​and the number of GNSS satellites used in the self-positioning solution, so as to improve the quality of the original self-positioning data from the positioning principle.

[0030] S3: Optimization of self-positioning results: Use a sliding window method to perform polynomial fitting on the filtered self-positioning results, eliminate the self-positioning results whose fitting residuals are greater than the third threshold, and perform interpolation processing based on the final fitted polynomial to obtain the optimized self-positioning results.

[0031] Specifically, the self-positioning result optimization includes: Set the sliding window length and sliding step length. The sliding window length is equal to the sliding step length. In this embodiment, both parameters are set to 600s. Divide the filtered self-positioning results into multiple segments of self-positioning results through a sliding window; For each segment of self-positioning results after division, perform polynomial fitting, preferably perform fifth-order polynomial fitting, and eliminate self-positioning results whose fitting residuals are greater than a third threshold (such as 10m, which is set according to the specific accuracy requirements). Iterate the polynomial fitting and elimination process until the fitting residuals of the retained self-positioning results are no greater than the third threshold, and obtain the final fitting polynomial. Interpolation processing is performed according to the final fitted polynomial. In this embodiment, uniform interpolation is performed for a series of self-positioning results with a time interval of 30 seconds to obtain an optimized self-positioning result.

[0032] The short-term low-orbit satellite orbit conforms to the polynomial characteristics. In order to make the discrete on-board self-positioning results better used for dynamic orbit determination, a sliding window polynomial fitting method is proposed to fit and smooth the self-positioning data, and the outliers in the self-positioning results are further eliminated by fitting the residuals. The smoothed self-positioning data can effectively improve the orbit determination accuracy.

[0033] S4: Satellite orbit determination: Based on the optimized self-positioning results, the low-orbit satellite is orbit determined using the dynamic fitting method to obtain the final low-orbit satellite tracking and control orbit.

[0034] Specifically, the satellite orbit determination process includes: Assumptions The self-positioning position on the satellite at time ; The position and velocity at the initial orbit time can be obtained by fitting the final fitting polynomial, and the position and velocity at the initial orbit time can be obtained by integration. The low-orbit satellite position at the time , and then establish the N-dimensional observation equation as follows: = ; In the formula, for The satellite motion state transfer matrix at time , , , are the corrections of the position, velocity and dynamic parameters of the low-orbit satellite at the time of initial orbit; Find the least squares optimal solution for the N-dimensional observation equation and perform iterative calculation until , , The iterative convergence conditions are met, and then the final orbit of the low-orbit satellite is obtained through orbit integration.

[0035] The above embodiment provides a method for determining the orbit of a low-orbit satellite measurement and control, which calculates the real-time satellite position based on the onboard GNSS pseudorange data and the broadcast ephemeris; in view of the gross error problem existing in high dynamic positioning, it is proposed to combine the satellite spatial distribution characteristic value and the positioning to use the satellite number threshold to eliminate the gross error in the self-positioning result; for the problem that the self-positioning result is a discrete point with unequal intervals, a sliding window polynomial is used to fit the self-positioning result, and the wild value in the discrete point is further eliminated by using the fitting residual; a series of smoothed self-positioning results are obtained based on the fitted polynomial interpolation, and the final low-orbit satellite measurement and control orbit is determined by dynamic orbit fitting. The data used in the present invention only includes single-frequency onboard GNSS pseudorange data and broadcast ephemeris, and the data type and data volume used are relatively small, so the cost is low; only a simple pseudorange single-point positioning algorithm and a dynamic orbit determination method are used, and the implementation process is relatively simple and the calculation amount is small; therefore, the technical solution of the present invention has a relatively simple implementation process, a low calculation cost and good real-time performance, and can realize the determination of the low-orbit satellite measurement and control orbit that does not rely on the ground station. Since the self-positioning results are solved in real time and processed through multiple outlier elimination, they are free from the dependence on ground stations and are less affected by the orbital maneuvers of low-orbit satellites. They can reflect more accurate satellite positions and have better orbit determination accuracy than the orbit determination results of ground station data measurement and control. The measurement and control tasks of a large number of low-orbit satellites in large low-orbit constellations are arduous and complex, and low-orbit satellites have frequent orbital maneuvers. This technical solution provides a way to solve the measurement and control orbit determination problems of low-orbit satellites in this situation.

[0036] It should also be noted that the rough orbital position can be obtained by single-point positioning using a low-orbit satellite onboard receiver, but this result is obtained by geometric solution and does not have orbital characteristics. The fusion of the dynamic fitting orbit determination method can make it have dynamic orbital characteristics, which is more in line with the actual satellite orbit. It is necessary to combine two key technologies to achieve the measurement and control orbit determination that does not rely on the ground station system. The difficulty lies in the reasonable preprocessing of the results of single-point positioning. Otherwise, if the data preprocessing is not appropriate, it may cause the orbit determination error to diverge. The present invention uses an effective method to eliminate the wild values ​​of single-point positioning, and performs smoothing processing that conforms to the orbital characteristics. The preprocessed data is used as the input for orbit determination. The gross errors in the single-point positioning results can be eliminated through this processing, so that the orbit determination results can be used for low-orbit satellite measurement and control with higher accuracy and reliability.

[0037] The embodiment of the present invention further provides a low-orbit satellite tracking and control orbit determination device, comprising: The initial self-positioning module is used to obtain the onboard GNSS pseudo-range observation values ​​and GNSS broadcast ephemeris, and obtain the self-positioning result of the low-orbit satellite through the pseudo-range single-point positioning algorithm; A filtering module is used to remove the corresponding self-positioning result when the number of GNSS satellites used for pseudo-range single-point positioning is lower than a first threshold; calculate the satellite spatial distribution characteristic value of the positioning epoch, and when the satellite spatial distribution characteristic value is greater than a second threshold, remove the corresponding self-positioning result; An optimization module is used to perform polynomial fitting on the filtered self-positioning results by using a sliding window method, eliminate the self-positioning results whose fitting residuals are greater than a third threshold, and perform interpolation processing according to the final fitted polynomial to obtain an optimized self-positioning result; The orbit determination module is used to determine the orbit of the low-orbit satellite using the dynamic fitting method based on the optimized self-positioning results to obtain the final low-orbit satellite measurement and control orbit.

[0038] It should be understood that the functional unit modules in various embodiments of the present invention may be concentrated in one processing unit, or each unit module may exist physically separately, or two or more unit modules may be integrated in one unit module, and may be implemented in the form of hardware or software.

[0039] The embodiment of the present invention further provides a low-orbit satellite tracking and control orbit determination device, which is configured on a low-orbit satellite and includes: The onboard receiver is used to receive onboard GNSS pseudorange observations and GNSS broadcast ephemeris and transmit them to the low-orbit satellite orbit determination module; The satellite-side computing module is configured to implement the low-orbit satellite tracking and control orbit determination method as described above.

[0040] An embodiment of the present invention further provides an electronic device, including: Memory on which computer programs or instructions are stored; The processor is used to load and execute the computer program or instructions to implement the low-orbit satellite tracking and control orbit determination method as described above.

[0041] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program or instruction is stored. When the computer program or instruction is executed by a processor, the method for determining the low-orbit satellite tracking and control orbit as described above is implemented.

[0042] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0043] It should be understood that the functional unit modules in various embodiments of the present invention may be concentrated in one processing unit, or each unit module may exist physically separately, or two or more unit modules may be integrated in one unit module, and may be implemented in the form of hardware or software.

[0044] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0045] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0046] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0047] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0048] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for determining a low-orbit satellite tracking and control orbit, characterized in that: The steps include: Obtain self-positioning results: Obtain onboard GNSS pseudo-range observations and GNSS broadcast ephemeris, and obtain the self-positioning results of low-orbit satellites through pseudo-range single-point positioning algorithm; Self-positioning result filtering: When the number of GNSS satellites used for pseudo-range single-point positioning is lower than the first threshold, the corresponding self-positioning result is eliminated; Calculate the satellite spatial distribution characteristic value of the positioning epoch, and when the satellite spatial distribution characteristic value is greater than a second threshold, remove the corresponding self-positioning result; Self-positioning result optimization: The filtered self-positioning results are fitted with a polynomial using a sliding window method, and the self-positioning results with fitting residuals greater than the third threshold are eliminated. Interpolation processing is performed based on the final fitted polynomial to obtain the optimized self-positioning results. Satellite orbit determination: Based on the optimized self-positioning results, the low-orbit satellite is orbit determined using the dynamic fitting method to obtain the final low-orbit satellite tracking and control orbit.

2. The method for determining the low-orbit satellite tracking and control orbit according to claim 1, characterized in that: The self-positioning result of the low-orbit satellite is obtained by solving the pseudo-range single-point positioning algorithm, specifically including: Spaceborne GNSS pseudorange observations The observation equation is expressed as follows: ； In the formula, the subscript , Represent the frequency and satellite receiver respectively, the superscript represents a GNSS satellite, Indicates the geometric distance from the GNSS satellite to the center of the onboard receiver; and They represent the receiver clock error and satellite clock error contained in the pseudorange respectively; and Respectively represent the frequency The hardware delay deviation between the receiver and the satellite, where the hardware delay at the receiver is received by the receiver clock error during positioning; represents the tropospheric delay error of pseudorange measurement, Indicates frequency The ionospheric delay, is the pseudorange observation noise, is the speed of light in a vacuum; The error equation after linearization of the observation equation of the satellite-borne GNSS pseudorange observation value is expressed as follows: ； In the formula, is the observation correction vector, is the design matrix, is the residual vector of pseudorange observations, is the unknown parameter correction vector, ,in , , is the coordinate correction number of the satellite receiver; The unknown parameter correction vector can be obtained by the least squares principle: ； In the formula, is the coefficient matrix of the normal equation, is the observation value weight matrix; Iterative calculation is performed until the unknown parameter correction vector meets the iterative convergence condition, and then the coordinates of the onboard receiver at the current epoch are obtained as the self-positioning result of the low-orbit satellite.

3. The method for determining the low-orbit satellite tracking and control orbit according to claim 1, characterized in that: The satellite spatial distribution characteristic value is calculated by the following method: The geometric distance from the GNSS satellite to the center of the onboard receiver Approximate position of satellite in low orbit Perform Taylor series expansion at , retain the first-order term, and the linearized equation is: ； In the formula, , , , is the geometric distance from the GNSS satellite to the center of the onboard receiver calculated from the approximate position, Indicates GNSS satellite coordinates; make ,have , subscript n is the number of GNSS satellites observed by the onboard receiver in the current epoch; Then the satellite spatial distribution characteristic value is .

4. The method for determining the low-orbit satellite tracking and control orbit according to claim 1, characterized in that: The self-positioning result optimization specifically includes: Set the sliding window length and sliding step size. The sliding window length is equal to the sliding step size. Divide the filtered self-positioning results into multiple segments of self-positioning results through a sliding window; For each segment of the self-positioning results after division, a polynomial fitting is performed, and the self-positioning results whose fitting residuals are greater than the third threshold are eliminated. The polynomial fitting and elimination process is iterated until the fitting residuals of the retained self-positioning results are all less than the third threshold, thereby obtaining the final fitting polynomial; Interpolation processing is performed according to the final fitted polynomial to obtain the optimized self-positioning result.

5. The method for determining the low-orbit satellite tracking and control orbit according to claim 1, characterized in that: The satellite orbit determination specifically includes: Assumptions The self-positioning position on the satellite at time ; The position and velocity at the initial orbit time can be obtained by fitting the final fitting polynomial, and the position and velocity at the initial orbit time can be obtained by integration. The low-orbit satellite position at the time , and then establish the N-dimensional observation equation as follows: = ； In the formula, for The satellite motion state transfer matrix at time , , , are the corrections of the position, velocity and dynamic parameters of the low-orbit satellite at the time of initial orbit; Find the least squares optimal solution for the N-dimensional observation equation and perform iterative calculation until , , The iterative convergence conditions are met, and then the final orbit of the low-orbit satellite is obtained through orbit integration.

6. The method for determining the low-orbit satellite tracking and control orbit according to claim 1, characterized in that: The first threshold is 8; the second threshold is 2; and the third threshold is 10m.

7. A low-orbit satellite tracking and control orbit determination device, characterized in that: include: The initial self-positioning module is used to obtain the onboard GNSS pseudo-range observation values ​​and GNSS broadcast ephemeris, and obtain the self-positioning result of the low-orbit satellite through the pseudo-range single-point positioning algorithm; A filtering module, used for discarding the corresponding self-positioning result when the number of GNSS satellites used for pseudo-range single point positioning is lower than a first threshold; Calculate the satellite spatial distribution characteristic value of the positioning epoch, and when the satellite spatial distribution characteristic value is greater than a second threshold, remove the corresponding self-positioning result; An optimization module is used to perform polynomial fitting on the filtered self-positioning results by using a sliding window method, eliminate the self-positioning results whose fitting residuals are greater than a third threshold, and perform interpolation processing according to the final fitted polynomial to obtain an optimized self-positioning result; The orbit determination module is used to determine the orbit of the low-orbit satellite using the dynamic fitting method based on the optimized self-positioning results to obtain the final low-orbit satellite measurement and control orbit.

8. A low-orbit satellite tracking and control orbit determination device, characterized in that: Configured on low-orbit satellites, including: The onboard receiver is used to receive onboard GNSS pseudorange observations and GNSS broadcast ephemeris and transmit them to the low-orbit satellite orbit determination module; The satellite-side computing module is configured to implement the low-orbit satellite tracking and control orbit determination method as described in any one of claims 1 to 6.

9. An electronic device, characterized in that: include: Memory on which computer programs or instructions are stored; A processor is used to load and execute the computer program or instruction to implement the low-orbit satellite tracking and control orbit determination method as described in any one of claims 1 to 6.

10. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed by the processor, the method for determining the low-orbit satellite tracking and control orbit as described in any one of claims 1 to 6 is implemented.

Images