Satellite clock error determination method and device based on inter-satellite link, and electronic equipment

Abstract

The invention discloses a satellite clock error determination method and device based on an inter-satellite link and electronic equipment, and relates to the field of spaceflight measurement and control, and the method comprises the steps: obtaining inter-satellite link measurement data, and carrying out the preprocessing of the data, and obtaining inter-satellite link data; segmenting the inter-satellite link data to obtain N segmented intervals and the inter-satellite link data of each segmented interval; based on the inter-satellite link data of the segmented interval and the theoretical inter-satellite distance, calculating the observation residual error of each observation moment in the segmented interval; based on the observation residual error of each observation moment in the segmented interval, calculating a clock error coefficient vector in the segmented interval by using a statistical weighted least square method; and determining the satellite clock error of the first observation satellite in each segmented interval and the satellite clock error of the second observation satellite in each segmented interval based on the clock error coefficient vectors of the segmented intervals. According to the method, the technical problem that the related satellite clock error estimation technology is low in precision under the complex background environment of the earth-moon space is solved.

Description

Technical Field

[0001] The present invention relates to the field of aerospace measurement and control or other related technical fields. Specifically, it relates to a method and device for determining satellite clock error based on inter-satellite links, and an electronic device. Background Technique

[0002] In the communication and navigation system in the Earth-Moon space, the inter-satellite link technology plays a key role. It can not only enhance the robustness and coverage of the system, but also provide accurate relative positioning information for spacecraft. The inter-satellite link provides a direct and efficient way for data transmission and navigation between spacecraft by measuring the distance or time delay between satellites. However, the measurement data of the inter-satellite link is affected by various factors, and satellite clock error is one of the main reasons for the decrease in the absolute accuracy of one-way inter-satellite measurements.

[0003] Satellite clock error refers to the deviation between the clock carried on the satellite and the standard time on the Earth (such as International Atomic Time TAI). This deviation can be caused by various factors, including the instability of the clock itself, environmental temperature difference, electromagnetic interference, gravity field change, and relativistic effects, etc. In the communication and navigation system in the Earth space, the processing of satellite clock error has been relatively mature. However, for the Earth-Moon space, due to the longer signal light travel time, more complex gravity environment, and more significant relativistic effects, the traditional satellite clock error estimation methods face new challenges.

[0004] In the Earth-Moon space communication and navigation system, the distance between satellites can reach hundreds of thousands of kilometers, which means that the signal propagation time increases significantly, and the small change of satellite clock error will be amplified, thus having a significant impact on the inter-satellite link measurement results. In addition, the satellites operate in the gravity gradient of the Earth and the Moon, experiencing a more diverse space environment, and the change trend of satellite clock error is also more complex. In the prior art, the methods for estimating satellite clock error mostly rely on two-way ranging by ground stations, autonomous calibration of on-board atomic clocks, or indirect estimation using inter-satellite link data. However, these methods have certain limitations in the Earth-Moon space environment:

[0005] Two-way ranging based on ground stations is subject to the influence of the Earth's atmosphere and the limitation of the measurement range, and may not be able to provide continuous and global coverage of clock error estimation.

[0006] The autonomous calibration of on-board atomic clocks requires periodic uploading of calibration parameters by ground stations, and errors may accumulate after long-term operation.

[0007] The indirect estimation method using inter-satellite link data may lack accuracy when dealing with the influence of complex space environment and high-precision requirements.

[0008] In response to the above problems, no effective solution has been proposed yet. Summary of the Invention

[0009] An embodiment of the present invention provides a method and apparatus for determining satellite clock offset based on inter-satellite links and an electronic device, so as to at least solve the technical problem of low accuracy of related satellite clock offset estimation technologies in the complex background environment of the earth-moon space.

[0010] According to one aspect of the embodiments of the present invention, a method for determining satellite clock offset based on inter-satellite links is provided, including: acquiring inter-satellite link measurement data, preprocessing the inter-satellite link measurement data to obtain inter-satellite link data, where the inter-satellite link data at least includes: the observation time, the observed inter-satellite distance between the first observed satellite and the second observed satellite at each of the observation times; segmenting the inter-satellite link data to obtain N segment intervals and the inter-satellite link data of each of the segment intervals, where N is a positive integer; calculating the observation residuals at each observation time within the segment interval based on the inter-satellite link data of the segment interval and the theoretical inter-satellite distance; calculating the clock offset coefficient vector within the segment interval by using the statistical weighted least squares method based on the observation residuals at each observation time within the segment interval; and determining the satellite clock offset of the first observed satellite within each of the segment intervals and the satellite clock offset of the second observed satellite within each of the segment intervals based on the clock offset coefficient vector of the segment interval.

[0011] Optionally, the step of segmenting the inter-satellite link data to obtain N segment intervals and the inter-satellite link data of each of the segment intervals includes: acquiring the observation duration of the entire observation process corresponding to the inter-satellite link data; determining the segmentation period based on the stability of the on-board clock; and dividing the inter-satellite link data based on the observation duration and the segmentation period to obtain N segment intervals and the inter-satellite link data of each of the segment intervals.

[0012] Optionally, after segmenting the inter-satellite link data, it further includes: establishing a high-order polynomial corresponding to the satellite clock offset of each segment interval, where the high-order polynomial is expressed as: where a(t) is the satellite clock offset of the segment interval, m represents the m-th segment interval, i represents the order, represents the i-th order polynomial coefficient of the satellite clock offset within the m-th segment interval, and n represents the highest order of the polynomial.

[0013] Optionally, the step of calculating the observation residuals at each observation moment within the segmented interval based on the inter-satellite link data and the theoretical inter-satellite distance of the segmented interval includes: extracting the observed inter-satellite distance at each observation moment from the inter-satellite link data of the segmented interval; transmitting a signal from the first observation satellite to the second observation satellite at each observation moment, calculating the first position vector of the first observation satellite at the time of signal transmission based on the ephemeris data of the first observation satellite, and calculating the second position vector of the second observation satellite at the signal reception moment based on the ephemeris data of the second observation satellite; calculating the theoretical inter-satellite distance at each observation moment based on the first position vector and the second position vector; calculating the difference between the observed inter-satellite distance and the theoretical inter-satellite distance at each observation moment to obtain the observation residuals at each observation moment within the segmented interval.

[0014] Optionally, the step of calculating the clock error coefficient vector within the segmented interval by using the statistical weighted least squares method based on the observation residuals at each observation moment within the segmented interval includes: establishing an observation equation at each observation moment based on the observation residuals at each observation moment, where the observation equation is expressed as: is the observation residual, represents the clock error coefficient vector of the first observation satellite, represents the clock error coefficient vector of the second observation satellite; performing fitting calculation on the observation equations at each observation moment by using the statistical weighted least squares method to obtain the clock error coefficient vector of the segmented interval.

[0015] Optionally, the step of determining the satellite clock error of the first observation satellite within each segmented interval and the satellite clock error of the second observation satellite within each segmented interval based on the clock error coefficient vector of the segmented interval includes: extracting the first clock error coefficient set of the first observation satellite from the clock error coefficient vector of the segmented interval; substituting the first clock error coefficient set into a high-order polynomial of the corresponding segmented interval for calculation to obtain the satellite clock error of the first observation satellite within the segmented interval; extracting the second clock error coefficient set of the second observation satellite from the clock error coefficient vector of the segmented interval; substituting the second clock error coefficient set into a high-order polynomial of the corresponding segmented interval for calculation to obtain the satellite clock error of the second observation satellite within the segmented interval.

[0016] Optionally, the step of preprocessing the inter-satellite link measurement data includes: detecting outliers in the inter-satellite link measurement data and removing the detected outliers; performing smoothing processing on the inter-satellite link measurement data to remove the noise in the data.

[0017] According to another aspect of the embodiments of the present invention, there is also provided a satellite clock error determination device based on an inter-satellite link, including: an acquisition unit, configured to acquire inter-satellite link measurement data, preprocess the inter-satellite link measurement data to obtain inter-satellite link data, where the inter-satellite link data at least includes: an observation time, and an observed inter-satellite distance between a first observed satellite and a second observed satellite at each of the observation times; a segmentation unit, configured to segment the inter-satellite link data to obtain N segmentation intervals and the inter-satellite link data of each of the segmentation intervals, where N is a positive integer; a first calculation unit, configured to calculate an observation residual at each observation time within the segmentation interval based on the inter-satellite link data of the segmentation interval and a theoretical inter-satellite distance; a second calculation unit, configured to calculate a clock error coefficient vector within the segmentation interval by using a statistical weighted least squares method based on the observation residuals at each observation time within the segmentation interval; a determination unit, configured to determine the satellite clock error of the first observed satellite within each of the segmentation intervals and the satellite clock error of the second observed satellite within each of the segmentation intervals based on the clock error coefficient vector of the segmentation interval.

[0018] Optionally, the segmentation unit includes: a first acquisition module, configured to acquire an observation duration of the entire observation process corresponding to the inter-satellite link data; a first determination module, configured to determine a segmentation period based on the stability of an on-board clock; a first division module, configured to divide the inter-satellite link data based on the observation duration and the segmentation period to obtain N segmentation intervals and the inter-satellite link data of each of the segmentation intervals.

[0019] Optionally, the satellite clock error determination device based on the inter-satellite link further includes: a first establishment module, configured to establish a high-order polynomial corresponding to the satellite clock error of each of the segmentation intervals, where the high-order polynomial is expressed as: where a(t) is the satellite clock error of the segmentation interval, m represents the m-th segmentation interval, i represents the order, represents the i-th order polynomial coefficient of the satellite clock error within the m-th segmentation interval, and n represents the highest order of the polynomial.

[0020] Optionally, the first calculation unit includes: a first extraction module, configured to extract the observed inter-satellite distances at each of the observation times from the inter-satellite link data of the segmented interval; a first calculation module, configured to transmit a signal from the first observation satellite to the second observation satellite at each of the observation times, calculate a first position vector of the first observation satellite at the time of signal transmission based on the ephemeris data of the first observation satellite, and calculate a second position vector of the second observation satellite at the time of signal reception based on the ephemeris data of the second observation satellite; a second calculation module, configured to calculate the theoretical inter-satellite distance at each observation time based on the first position vector and the second position vector; and a third calculation module, configured to calculate the difference between the observed inter-satellite distance and the theoretical inter-satellite distance at each observation time to obtain the observation residuals at each observation time within the segmented interval.

[0021] Optionally, the second calculation unit includes: a second establishment module, configured to establish an observation equation at each of the observation times based on the observation residuals at each of the observation times, where the observation equation is expressed as: is the observation residual, represents the clock error coefficient vector of the first observation satellite, represents the clock error coefficient vector of the second observation satellite; a first fitting module, configured to perform fitting calculation on the observation equations at each of the observation times by means of statistical weighted least squares method to obtain the clock error coefficient vector of the segmented interval.

[0022] Optionally, the determination unit includes: a second extraction module, configured to extract a first set of clock error coefficients of the first observation satellite from the clock error coefficient vector of the segmented interval; a fourth calculation module, configured to substitute the first set of clock error coefficients into a high-order polynomial of the corresponding segmented interval for calculation to obtain the satellite clock error of the first observation satellite within the segmented interval; a third extraction module, configured to extract a second set of clock error coefficients of the second observation satellite from the clock error coefficient vector of the segmented interval; and a fifth calculation module, configured to substitute the second set of clock error coefficients into a high-order polynomial of the corresponding segmented interval for calculation to obtain the satellite clock error of the second observation satellite within the segmented interval.

[0023] Optionally, the satellite clock error determination device based on the inter-satellite link further includes: a first detection module, configured to perform outlier detection on the inter-satellite link measurement data and remove the detected outliers; and a first processing module, configured to perform smoothing processing on the inter-satellite link measurement data to remove the noise in the data.

[0024] According to another aspect of the embodiments of the present invention, there is also provided a computer-readable storage medium, which includes a stored computer program. When the computer program runs, it controls the device where the computer-readable storage medium is located to execute any one of the above satellite clock difference determination methods based on the inter-satellite link.

[0025] According to another aspect of the embodiments of the present invention, there is also provided an electronic device, including one or more processors and a memory. The memory is used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors are caused to implement any one of the above satellite clock difference determination methods based on the inter-satellite link.

[0026] In the present application, through the following steps: First, obtain the inter-satellite link measurement data, preprocess the inter-satellite link measurement data to obtain the inter-satellite link data, where the inter-satellite link data at least includes: the observation time, the observed inter-satellite distance between the first observed satellite and the second observed satellite at each observation time, and segment the inter-satellite link data to obtain N segmented intervals and the inter-satellite link data of each segmented interval, where N is a positive integer. Then, calculate the observation residuals at each observation time within the segmented interval based on the inter-satellite link data and the theoretical inter-satellite distance of the segmented interval, and calculate the clock difference coefficient vector within the segmented interval by using the statistical weighted least squares method based on the observation residuals at each observation time within the segmented interval. Finally, determine the satellite clock difference of the first observed satellite within each segmented interval and the satellite clock difference of the second observed satellite within each segmented interval based on the clock difference coefficient vector of the segmented interval.

[0027] In the present application, the non-linear change trend of the on-board clock is characterized by a high-order polynomial, and the statistical weighted least squares method of the observation data is used to fit the coefficients of the high-order polynomial, that is, the clock difference coefficients. Then, the clock difference coefficients are substituted into the high-order polynomial to solve, and the satellite clock differences of each observation interval are obtained. The satellite clock differences adopt a segmented high-order representation method, which allows for a more accurate description of the satellite clock differences within each segment, achieving the purpose of accurately calculating the satellite clock differences, obtaining the technical effect of improving the accuracy of the satellite clock difference calculation results, and further solving the technical problem of the low accuracy of the relevant satellite clock difference estimation technology in the complex background environment of the earth-moon space. Description of the Drawings

[0028] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0029] Figure 1 is a flowchart of an optional satellite clock difference determination method based on the inter-satellite link according to the embodiments of the present invention;

[0030] Figure 2 It is an optional segmented schematic diagram of satellite clock offset according to an embodiment of the present invention;

[0031] Figure 3 It is a schematic diagram of an optional satellite clock offset determination device based on an inter-satellite link according to an embodiment of the present invention;

[0032] Figure 4 It is a hardware structure block diagram of an electronic device (or mobile device) that executes a method for determining satellite clock offset based on an inter-satellite link according to an embodiment of the present invention. Detailed implementation manners

[0033] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order different from those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily need to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0035] It should be noted that the method and device for determining satellite clock offset based on an inter-satellite link in the present application can be used in the field of space TT&C when determining the satellite clock offset at each moment based on a segmented high-order polynomial, and can also be used in any field other than the field of space TT&C when determining the satellite clock offset at each moment based on a segmented high-order polynomial. The application field of the method and device for determining satellite clock offset based on an inter-satellite link in the present application is not limited.

[0036] It should be noted that the relevant information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are information and data authorized by the user or fully authorized by all parties. Moreover, for the processing of relevant data such as collection, storage, use, processing, transmission, provision, disclosure, and application, all comply with the relevant laws, regulations, and standards of the relevant regions, adopt necessary confidentiality measures, do not violate public order and good customs, and provide corresponding operation entrances for users to choose to authorize or refuse. For example, there is an interface between this system and relevant users or institutions. Before obtaining relevant information, a request for acquisition needs to be sent to the aforementioned users or institutions through the interface, and after receiving the consent information feedback from the aforementioned users or institutions, the relevant information can be obtained.

[0037] It should be noted that when collecting and analyzing customer information in this application, a corresponding operation entrance is provided for users to choose to agree or refuse the automated decision-making results; if the user chooses to refuse, the expert decision-making process will be entered.

[0038] The following embodiments of the present invention can be applied to a satellite clock difference determination system / application / device based on an inter-satellite link. A method for estimating the satellite clock difference based on an inter-satellite link proposed by the present invention can characterize the variation of the satellite clock difference in the Earth-Moon space through a high-order polynomial, and calculate the satellite clock difference through the satellite combination of the inter-satellite link, thereby realizing high-precision correction of the ranging data of the inter-satellite link and providing high-precision data support for the orbit determination calculation of spacecraft in the Earth-Moon space.

[0039] The present invention will be described in detail below in conjunction with each embodiment.

[0040] Embodiment 1

[0041] According to an embodiment of the present invention, an embodiment of a method for determining the satellite clock difference based on an inter-satellite link is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order from here.

[0042] Figure 1 is a flowchart of an optional method for determining the satellite clock difference based on an inter-satellite link according to an embodiment of the present invention. As Figure 1 shown, the method includes the following steps:

[0043] Step S101, obtain the inter-satellite link measurement data, and preprocess the inter-satellite link measurement data to obtain the inter-satellite link data.

[0044] In the above step S101, the inter-satellite link can be a wireless communication link established between any two or more satellites, especially for the inter-satellite link within the Earth-Moon space range or applicable to the Earth-Moon space environment. The tracking and control signals of the inter-satellite link can obtain the relative distance between satellites for satellite orbit calculation. The essence of inter-satellite link measurement is the time delay of the signal transmitted between two satellites, which includes both the geometric distance between satellites and the clock biases of the two satellites respectively. Due to the physical properties of the on-board clock itself and the space environment it is in, it is difficult to accurately model the error of the on-board clock, which directly manifests as a systematic deviation in inter-satellite ranging. The inter-satellite link in the Earth-Moon space is different from that in the Earth space. Its main significant features include that the light travel time of signals in the Earth-Moon space is longer and the space gravitational environment is more complex, resulting in more significant satellite clock biases caused by relativistic effects.

[0045] In the embodiments of the present invention, the inter-satellite link data at least includes: the observation time, and the observation distance between the first observation satellite and the second observation satellite at each observation time.

[0046] In the embodiments of the present invention, from the perspective of satellite clock bias, the satellite clock biases of two satellites are calculated through inter-satellite link data, so as to provide more accurate measurement data for aerospace exploration, and further provide high-precision time synchronization services and positioning data for the Earth-Moon space communication and navigation system.

[0047] Optionally, the steps of preprocessing the inter-satellite link measurement data include: detecting outliers in the inter-satellite link measurement data and removing the detected outliers; smoothing the inter-satellite link measurement data to remove the noise in the data.

[0048] It should be noted that when observing a target using the inter-satellite link, the obtained inter-satellite link measurement data is at any time and the data volume is large. After obtaining the inter-satellite link measurement data, it is first necessary to preprocess the data. Specifically, various statistical or machine learning methods are used to detect outliers in the data, and the observed values that significantly deviate from the normal range in the inter-satellite link measurement data are identified and removed according to the data distribution or model prediction. At the same time, the preprocessing also includes smoothing the inter-satellite link measurement data to remove the noise in the data. The preprocessing can ensure the accuracy of the data, enhance the stability of the data, improve the accuracy of satellite clock bias estimation and the accuracy of satellite clock bias calculation.

[0049] In another optional embodiment, the steps of preprocessing the inter-satellite link measurement data further include: obtaining the observation timestamp of each inter-satellite link measurement data, sorting the inter-satellite link measurement data according to the observation timestamp to obtain time-series inter-satellite link data, which is used as the data basis for subsequent segmentation.

[0050] Step S102: Segment the inter-satellite link data to obtain N segmented intervals and the inter-satellite link data for each segmented interval, where N is a positive integer.

[0051] In the above step S102, the inter-satellite link data (i.e., the above-mentioned time-series inter-satellite link data) is divided into multiple segmented intervals by segmentation. Due to the large variations in the performance of satellite clocks and environmental conditions, dividing the inter-satellite link data enables the performance of the satellite clock and environmental conditions to remain in a relatively stable state within each segmented interval with a short time duration. Thus, the changing trend of satellite clock error can be modeled more accurately.

[0052] In this embodiment, in the application scenario of the Earth-Moon space communication and navigation system, the stability of the satellite clock may be affected by the complex space environment and long-term operation, showing a non-linear changing trend. Piecewise high-order polynomials can more accurately describe such complex clock error changes, and based on the above-mentioned segmented data, the uncertainties accumulated during long-term observations can be reduced, improving the credibility of clock error estimation.

[0053] Optionally, the step of segmenting the inter-satellite link data to obtain N segmented intervals and the inter-satellite link data for each segmented interval includes: obtaining the observation duration of the entire observation process corresponding to the inter-satellite link data; determining the segmentation period based on the stability of the on-board clock; and dividing the inter-satellite link data based on the observation duration and the segmentation period to obtain N segmented intervals and the inter-satellite link data for each segmented interval.

[0054] Specifically, first, the observation duration of the entire observation process corresponding to the inter-satellite link data is determined by recording the time difference between the first observation and the last observation. Secondly, according to the stability index of the satellite clock and the characteristics of the inter-satellite link data, a reasonable segmentation time length, i.e., the segmentation period, is determined. This time length should be sufficient to capture the significant changes in satellite clock error but not too long to cause the clock error changes to be too complex to accurately model. Then, based on the obtained observation duration and the determined segmentation period, the total number N of segmented intervals that can be divided is calculated, and the observation time window is equally divided into N consecutive intervals according to the segmentation period. The entire observation time window is evenly divided to obtain N segmented intervals, where N is a positive integer selected according to specific observation requirements and data characteristics.

[0055] Exemplarily, when segmenting the inter-satellite link data, all the inter-satellite link data is sorted in chronological order to determine the time interval [t beg , t end that contains all the inter-satellite link observations, and the time length of the observation interval (corresponding to the above-mentioned observation duration) t dur = t beg - t end; Determine the time length (corresponding to the above-mentioned segmentation period) T of the segmented representation of the clock error according to the stability of the satellite on-board clock, and combine it with the time length of the observation interval, the number of segments of the satellite clock error [] represents rounding up.

[0056] Through the above steps, the segmentation period and the number of segmentation intervals are reasonably selected, significantly improving the efficiency of inter-satellite link data processing and the accuracy of satellite clock error estimation.

[0057] Optionally, after segmenting the inter-satellite link data, it further includes: establishing a high-order polynomial corresponding to the satellite clock error of each segmentation interval, where the high-order polynomial is expressed as: where a(t) is the satellite clock error of the segmentation interval, m represents the m-th segmentation interval, i represents the order, represents the i-th order polynomial coefficient of the satellite clock error in the m-th segmentation interval, and n represents the highest order of the polynomial.

[0058] In some embodiments, the purpose of segmenting the inter-satellite link data is to construct a high-order polynomial within the segmentation interval, so as to fit the satellite clock error through the segmented high-order polynomial, and the changing trend of the satellite clock error can be modeled more accurately, especially when the performance of the satellite clock changes greatly over time. Specifically, a high-order polynomial corresponding to the satellite clock error is established within each segmentation interval. The high-order polynomial contains polynomial coefficients of each order, that is, clock error coefficients. Then, according to the inter-satellite measurement data within each segmentation interval, the set of polynomial coefficients within the segmentation interval is fitted, and thus the polynomial coefficients of each order are substituted into the high-order polynomial to solve for the satellite clock error.

[0059] Exemplarily, the satellite clock error of each segmentation interval is expressed as a high-order polynomial, and the high-order polynomial of the satellite clock error can be expressed as:

[0060]

[0061] In the formula, represents the high-order polynomial coefficient within the segmentation interval, m = 0, 1,..., N - 1 represents the starting point of the segmentation interval, and n represents the highest order of the polynomial.

[0062] Step S103, calculate the observation residuals at each observation moment within the segmentation interval based on the inter-satellite link data and the theoretical inter-satellite distance of the segmentation interval.

[0063] Figure 2 is an optional schematic diagram of the segmentation of the satellite clock error according to an embodiment of the present invention. As Figure 2 shown, the observation process corresponding to the inter-satellite link data is divided into N segmentation intervals, that is Figure 2 in [t 0 , t 1 , [t1 ,t 2 , [t 2 ,t 3 , …, [t N-2 ,t N-1 , [t N-1 ,t N , each segmented interval corresponds to a high-order polynomial of satellite clock offset, such as Figure 2 in, [t 0 ,t 1 corresponds to the segmented high-order polynomial as follows: [t 1 ,t 2 corresponds to the segmented high-order polynomial as follows: [t 2 ,t 3 corresponds to the segmented high-order polynomial as follows: [t N-2 ,t N-1 corresponds to the segmented high-order polynomial as follows: [t N-1 ,t N corresponds to the segmented high-order polynomial as follows:

[0064] In the above step S103, by taking the difference between the inter-satellite link data and the theoretical inter-satellite distance (i.e., the observation residual), the influence of satellite clock offset on the inter-satellite link distance measurement is extracted, providing a solid data basis for the high-precision estimation of satellite clock offset. The calculation of the observation residual can not only reveal the systematic deviation of the inter-satellite link measurement, but also help identify the performance problems of satellite clocks and environmental interference factors, providing key information for data correction and system optimization.

[0065] Optionally, the steps of calculating the observation residuals at each observation moment within the segmented interval based on the inter-satellite link data and the theoretical inter-satellite distance within the segmented interval include: extracting the observed inter-satellite distances at each observation moment from the inter-satellite link data within the segmented interval; transmitting signals from the first observation satellite to the second observation satellite at each observation moment, calculating the first position vector of the first observation satellite at the signal transmission time based on the ephemeris data of the first observation satellite, and calculating the second position vector of the second observation satellite at the signal reception time based on the ephemeris data of the second observation satellite; calculating the theoretical inter-satellite distance at each observation moment based on the first position vector and the second position vector; calculating the difference between the observed inter-satellite distance and the theoretical inter-satellite distance at each observation moment to obtain the observation residuals at each observation moment within the segmented interval.

[0066] Specifically, when calculating the observation residual, first extract the inter-satellite distance values observed at each moment from the inter-satellite link data to obtain the observed inter-satellite distance, and then compare it with the theoretical inter-satellite distance value at the corresponding moment. Calculate the difference between the two, that is, the observation residual, and this difference reflects the influence of the satellite clock error on the observed distance.

[0067] Exemplarily, mark the inter-satellite link measurement as the observed inter-satellite distance measured by the signal transmitted from satellite A (such as the first observation satellite) and received by satellite B (such as the second observation satellite). Calculate the inter-satellite link measurement data at time t corresponding theoretical inter-satellite distance In the formula, represents the position vector of satellite A at the signal emission moment (corresponding to the above first position vector), represents the position vector of satellite B at the signal reception moment (corresponding to the above second position vector). Then the inter-satellite link measurement can be expressed as:

[0068] The inter-satellite link measurement value includes the clock errors of satellites A and B, and its expression is:

[0069]

[0070] where c1 represents the clock error coefficient of satellite A, and c2 represents the clock error coefficient of satellite B. Define the observation residual of the inter-satellite link as

[0071] Step S104, based on the observation residuals at each observation moment within the segmented interval, use the statistical weighted least squares method to calculate the clock error coefficient vector within the segmented interval.

[0072] In the above step S104, based on the observation residuals at each observation moment within the segmented interval, construct a design matrix (corresponding to the above observation equation), and use the statistical weighted least squares method to calculate the clock error coefficient vector within the segmented interval. The method of estimating the clock error coefficient using the statistical weighted least squares method provides high-precision satellite clock error modeling parameters, which is the key to realizing the calibration of inter-satellite link data and improving the accuracy of spacecraft orbit calculation.

[0073] Optionally, the step of calculating the clock error coefficient vector within the segmented interval based on the observation residuals at each observation moment within the segmented interval using the statistical weighted least squares method includes: establishing an observation equation for each observation moment based on the observation residuals at each observation moment, where the observation equation is expressed as: is the observation residual, represents the clock error coefficient vector of the first observation satellite, Denote the clock error coefficient vector of the second observation satellite; through statistical weighted least squares method, the observation equations at each observation moment are fitted and calculated to obtain the clock error coefficient vector of the segmented interval.

[0074] Specifically, for each segmented interval, based on the observation residuals calculated in the foregoing steps, prepare a list or matrix containing the observation residuals at all observation moments, and construct a design matrix according to the order and form of the segmented high-order polynomial model. Each row of this matrix corresponds to an observation moment and contains the coefficients of the polynomial terms corresponding to that moment, so as to reflect the linear relationship between the observation residuals and the clock error coefficients. Then, by solving the statistical weighted least squares problem, that is, minimizing the sum of the squares of the observation residuals, the clock error coefficient vector is obtained.

[0075] In another optional embodiment, a weight matrix W is constructed based on the statistical characteristics (such as variance or standard deviation) of the observation residuals. Each term W of the weight matrix i reflects the reliability of the data at the corresponding observation moment and is usually inversely proportional to the variance of the observation residuals. This strategy ensures that high-quality data plays a greater role in clock error estimation, while the impact of low-quality data on the result is appropriately weakened.

[0076] Exemplarily, calculate the partial derivatives of the inter-satellite link measurement values with respect to the clock errors of satellites A and B. Calculate the partial derivative of the clock error coefficient of satellite A (corresponding to the first observation satellite above) with respect to any moment t.

[0077]

[0078] The above is the clock error coefficient of the first observation satellite.

[0079] Calculate the partial derivative of the clock error coefficient of satellite B (corresponding to the second observation satellite above) with respect to any moment t.

[0080]

[0081] The above is the clock error coefficient of the second observation satellite.

[0082] Each set of observation data, that is, the data within each segmented interval, can form the following equation (corresponding to the above observation equation).

[0083]

[0084] In the formula, denotes the clock error coefficient vector of satellite A in each segmented interval. denotes the clock error coefficient vector of satellite B in each segmented interval.

[0085] Specifically, it can be expanded as follows:

[0086]

[0087] Marker Then, for a set of observed data, the above can be rewritten as

[0088]

[0089] For k sets of observed data, it can be written as:

[0090]

[0091] Marker O = [o 1 , o 2 , …, o k T , H = [h 1 , h 2 , …, h l T Then, the solution of the above formula can be expressed as:

[0092]

[0093] From this, the clock error coefficient vector can be solved, which includes the clock error coefficients of the first observed satellite and the second observed satellite at each moment in the segmented interval.

[0094] Step S105: Determine the satellite clock error of the first observed satellite in each segmented interval and the satellite clock error of the second observed satellite in each segmented interval based on the clock error coefficient vector of the segmented interval.

[0095] In the above step S105, the clock error coefficients of the first observed satellite and the second observed satellite are extracted according to the solved clock error coefficient vector, and combined with the pre-established high-order polynomial to solve the satellite clock error of the observed satellite in the segmented interval. In the embodiment of the present invention, the flexibility of the high-order polynomial model and the accuracy of the statistical weighted least squares method are utilized to achieve fine estimation of the satellite clock error.

[0096] ​​Optionally, the steps of determining the satellite clock error of the first observed satellite and the satellite clock error of the second observed satellite in each segmented interval based on the clock error coefficient vector of the segmented interval include: extracting the first clock error coefficient set of the first observed satellite from the clock error coefficient vector of the segmented interval; substituting the first clock error coefficient set into the high-order polynomial of the corresponding segmented interval for calculation to obtain the satellite clock error of the first observed satellite in the segmented interval; extracting the second clock error coefficient set of the second observed satellite from the clock error coefficient vector of the segmented interval; substituting the second clock error coefficient set into the high-order polynomial of the corresponding segmented interval for calculation to obtain the satellite clock error of the second observed satellite in the segmented interval.

[0097] Specifically, the clock error coefficient vector is calculated by the statistical weighted least squares method and contains the description of the clock error changes of the first observed satellite and the second observed satellite in multiple segmented intervals. Therefore, it is first necessary to identify which coefficients correspond to the clock error changes of the first observed satellite in the current segmented interval, then extract these coefficients to form the first clock error coefficient set, substitute the first clock error coefficient set into the high-order polynomial model of the corresponding segmented interval of the first observed satellite, and perform mathematical operations to obtain the satellite clock error of the first observed satellite in the segmented interval. Similarly, select the coefficient set related to the clock error change of the second observed satellite from the clock error coefficient vector, substitute the second clock error coefficient set into the high-order polynomial model corresponding to the second observed satellite, and calculate the satellite clock error of the second observed satellite in the segmented interval.

[0098] Through the above steps, first obtain the inter-satellite link measurement data, preprocess the inter-satellite link measurement data to obtain the inter-satellite link data, where the inter-satellite link data at least includes: the observation time, the observed inter-satellite distance between the first observed satellite and the second observed satellite at each observation time, and segment the inter-satellite link data to obtain N segmented intervals and the inter-satellite link data of each segmented interval, where N is a positive integer, then calculate the observation residuals at each observation time in the segmented interval based on the inter-satellite link data and the theoretical inter-satellite distance of the segmented interval, and calculate the clock error coefficient vector in the segmented interval by using the statistical weighted least squares method based on the observation residuals at each observation time in the segmented interval, and finally determine the satellite clock error of the first observed satellite and the satellite clock error of the second observed satellite in each segmented interval based on the clock error coefficient vector of the segmented interval.

[0099] In this embodiment, the non-linear variation trend of the spaceborne clock is characterized by a high-order polynomial, and the high-order polynomial coefficients, that is, the clock error coefficients, are fitted by using the statistical weighted least squares method of the observed data. Then, the satellite clock errors in each observation interval are obtained by substituting the clock error coefficients into the high-order polynomial. The satellite clock error adopts a segmented high-order characterization method, which allows for a more accurate description of the satellite clock error within each segment, achieving the purpose of accurately calculating the satellite clock error, obtaining the technical effect of improving the accuracy of the satellite clock error calculation result, and further solving the technical problem of the low accuracy of the related satellite clock error estimation technology in the complex background environment of the Earth-Moon space.

[0100] A detailed description will be given below in conjunction with another embodiment.

[0101] Embodiment 2

[0102] A satellite clock error determination device based on an inter-satellite link provided in this embodiment includes multiple implementation units. Each implementation unit corresponds to each implementation step in Embodiment 1 above. The specific implementation manner and beneficial effects can be referred to the foregoing method embodiment and will not be elaborated here.

[0103] Figure 3 It is a schematic diagram of an optional satellite clock error determination device based on an inter-satellite link according to an embodiment of the present invention. As Figure 3 shown, the satellite clock error determination device based on the inter-satellite link includes: an acquisition unit 31, a segmentation unit 32, a first calculation unit 33, a second calculation unit 34, and a determination unit 35. Among them,

[0104] The acquisition unit 31 is configured to acquire inter-satellite link measurement data, preprocess the inter-satellite link measurement data to obtain inter-satellite link data, where the inter-satellite link data at least includes: the observation time, and the observed inter-satellite distance between the first observed satellite and the second observed satellite at each observation time;

[0105] The segmentation unit 32 is configured to segment the inter-satellite link data to obtain N segmented intervals and the inter-satellite link data of each segmented interval, where N is a positive integer;

[0106] The first calculation unit 33 is configured to calculate the observation residuals at each observation time within the segmented interval based on the inter-satellite link data of the segmented interval and the theoretical inter-satellite distance;

[0107] The second calculation unit 34 is configured to calculate the clock error coefficient vector within the segmented interval by using the statistical weighted least squares method based on the observation residuals at each observation time within the segmented interval;

[0108] The determination unit 35 is configured to determine the satellite clock error of the first observed satellite within each segmented interval and the satellite clock error of the second observed satellite within each segmented interval based on the clock error coefficient vector of the segmented interval.

[0109] The above satellite clock error determination device based on inter-satellite links obtains inter-satellite link measurement data through an acquisition unit 31, preprocesses the inter-satellite link measurement data to obtain inter-satellite link data, where the inter-satellite link data at least includes: the observation time, and the observed inter-satellite distance between the first observed satellite and the second observed satellite at each observation time; segments the inter-satellite link data through a segmentation unit 32 to obtain N segmentation intervals and the inter-satellite link data of each segmentation interval, where N is a positive integer; calculates the observation residuals at each observation time within the segmentation interval based on the inter-satellite link data and the theoretical inter-satellite distance of the segmentation interval through a first calculation unit 33; calculates the clock error coefficient vector within the segmentation interval by using the statistical weighted least squares method based on the observation residuals at each observation time within the segmentation interval through a second calculation unit 34; and determines the satellite clock error of the first observed satellite and the satellite clock error of the second observed satellite within each segmentation interval based on the clock error coefficient vector of the segmentation interval through a determination unit 35.

[0110] In this embodiment, the non-linear change trend of the on-board clock is characterized by a high-order polynomial, and the high-order polynomial coefficients, that is, the clock error coefficients, are parameter-fitted by using the statistical weighted least squares method of the observation data. Then, the clock error coefficients are substituted into the high-order polynomial for solution to obtain the satellite clock error of each observation interval. The satellite clock error adopts a segmented high-order characterization method, which allows for a more accurate description of the satellite clock error within each segment, achieving the purpose of accurately calculating the satellite clock error and obtaining the technical effect of improving the accuracy of the satellite clock error calculation result. Furthermore, it solves the technical problem of the low accuracy of related satellite clock error estimation technologies in the complex background environment of the earth-moon space.

[0111] Optionally, the segmentation unit 32 includes: a first acquisition module for acquiring the observation duration of the entire observation process corresponding to the inter-satellite link data; and a first determination module for dividing the inter-satellite link data based on the observation duration and the segmentation period to obtain N segmentation intervals and the inter-satellite link data of each segmentation interval.

[0112] Optionally, the satellite clock error determination device based on inter-satellite links further includes: a first establishment module for establishing a high-order polynomial corresponding to the satellite clock error of each segmentation interval, where the high-order polynomial is expressed as: where a(t) is the satellite clock error of the segmentation interval, m represents the m-th segmentation interval, i represents the order, represents the i-th order polynomial coefficient of the satellite clock error within the m-th segmentation interval, and n represents the highest order of the polynomial.

[0113] Optionally, the first calculation unit 33 includes: a first extraction module, configured to extract the observed inter-satellite distances at each observation time from the inter-satellite link data in the segmented interval; a first calculation module, configured to transmit a signal from the first observation satellite to the second observation satellite at each observation time, calculate the first position vector of the first observation satellite at the signal transmission time based on the ephemeris data of the first observation satellite, and calculate the second position vector of the second observation satellite at the signal reception time based on the ephemeris data of the second observation satellite; a second calculation module, configured to calculate the theoretical inter-satellite distances at each observation time based on the first position vector and the second position vector; a third calculation module, configured to calculate the difference between the observed inter-satellite distance and the theoretical inter-satellite distance at each observation time, and obtain the observation residuals at each observation time in the segmented interval.

[0114] Optionally, the second calculation unit 34 includes: a second establishment module, configured to establish an observation equation at each observation time based on the observation residuals at each observation time, where the observation equation is expressed as: is the observation residual, represents the clock error coefficient vector of the first observation satellite, represents the clock error coefficient vector of the second observation satellite; a first fitting module, configured to perform fitting calculation on the observation equations at each observation time by means of statistical weighted least squares method to obtain the clock error coefficient vector of the segmented interval.

[0115] Optionally, the determination unit 35 includes: a second extraction module, configured to extract the first clock error coefficient set of the first observation satellite from the clock error coefficient vector of the segmented interval; a fourth calculation module, configured to substitute the first clock error coefficient set into the high-order polynomial corresponding to the segmented interval for calculation to obtain the satellite clock error of the first observation satellite in the segmented interval; a third extraction module, configured to extract the second clock error coefficient set of the second observation satellite from the clock error coefficient vector of the segmented interval; a fifth calculation module, configured to substitute the second clock error coefficient set into the high-order polynomial corresponding to the segmented interval for calculation to obtain the satellite clock error of the second observation satellite in the segmented interval.

[0116] Optionally, the satellite clock error determination device based on the inter-satellite link further includes: a first detection module, configured to perform outlier detection on the inter-satellite link measurement data and eliminate the detected outliers; a first processing module, configured to perform smoothing processing on the inter-satellite link measurement data to remove the noise in the data.

[0117] The above satellite clock error determination device based on the inter-satellite link may further include a processor and a memory. The above acquisition unit 31, segmentation unit 32, first calculation unit 33, second calculation unit 34, determination unit 35, etc. are all stored in the memory as program units, and the corresponding functions are implemented by the processor executing the above program units stored in the memory.

[0118] The above-mentioned processor includes a kernel, which retrieves corresponding program units from the memory. One or more kernels can be set, and the measurement and control accuracy of satellite clock error can be improved by adjusting the kernel parameters.

[0119] The above-mentioned memory may include non-permanent memory in a computer-readable medium, random access memory (RAM), and / or non-volatile memory in the form of, for example, read-only memory (ROM) or flash memory (flash RAM). The memory includes at least one memory chip.

[0120] According to another aspect of the embodiments of the present invention, there is also provided a computer-readable storage medium, which includes a stored computer program. When the computer program runs, it controls the device where the computer-readable storage medium is located to execute any one of the above-mentioned satellite clock error determination methods based on an inter-satellite link.

[0121] According to another aspect of the embodiments of the present invention, there is also provided an electronic device, which includes one or more processors and a memory. The memory is used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors are caused to implement any one of the above-mentioned satellite clock error determination methods based on an inter-satellite link.

[0122] According to another aspect of the embodiments of the present invention, there is also provided a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements any one of the above-mentioned satellite clock error determination methods based on an inter-satellite link.

[0123] The present application also provides a computer program product, which is adapted to execute a program initialized with the following method steps when executed on a data processing device: obtaining inter-satellite link measurement data, preprocessing the inter-satellite link measurement data to obtain inter-satellite link data, where the inter-satellite link data at least includes: the observation time, the observed inter-satellite distance between the first observed satellite and the second observed satellite at each observation time; segmenting the inter-satellite link data to obtain N segment intervals and the inter-satellite link data of each segment interval, where N is a positive integer; calculating the observation residuals at each observation time within the segment interval based on the inter-satellite link data of the segment interval and the theoretical inter-satellite distance; calculating the clock error coefficient vector within the segment interval using the statistical weighted least squares method based on the observation residuals at each observation time within the segment interval; determining the satellite clock error of the first observed satellite within each segment interval and the satellite clock error of the second observed satellite within each segment interval based on the clock error coefficient vector of the segment interval.

[0124] Optionally, the steps of segmenting the inter-satellite link data to obtain N segment intervals and the inter-satellite link data of each segment interval include: obtaining the observation duration of the entire observation process corresponding to the inter-satellite link data; determining the segmentation period based on the stability of the on-board clock; and dividing the inter-satellite link data based on the observation duration and the segmentation period to obtain N segment intervals and the inter-satellite link data of each segment interval.

[0125] Optionally, after segmenting the inter-satellite link data, it further includes: establishing a high-order polynomial corresponding to the satellite clock offset of each segment interval, where the high-order polynomial is expressed as: where a(t) is the satellite clock offset of the segment interval, m represents the m-th segment interval, i represents the order, represents the i-th order polynomial coefficient of the satellite clock offset within the m-th segment interval, and n represents the highest order of the polynomial.

[0126] Optionally, the steps of calculating the observation residuals at each observation moment within the segment interval based on the inter-satellite link data of the segment interval and the theoretical inter-satellite distance include: extracting the observed inter-satellite distance at each observation moment from the inter-satellite link data of the segment interval; transmitting a signal from the first observation satellite to the second observation satellite at each observation moment, calculating the first position vector of the first observation satellite at the signal transmission moment based on the ephemeris data of the first observation satellite, and calculating the second position vector of the second observation satellite at the signal reception moment based on the ephemeris data of the second observation satellite; calculating the theoretical inter-satellite distance at each observation moment based on the first position vector and the second position vector; and calculating the difference between the observed inter-satellite distance and the theoretical inter-satellite distance at each observation moment to obtain the observation residuals at each observation moment within the segment interval.

[0127] Optionally, the steps of calculating the clock offset coefficient vector within the segment interval by using the statistical weighted least squares method based on the observation residuals at each observation moment within the segment interval include: establishing an observation equation at each observation moment based on the observation residuals, where the observation equation is expressed as: is the observation residual, represents the clock offset coefficient vector of the first observation satellite, represents the clock offset coefficient vector of the second observation satellite; and performing fitting calculation on the observation equations at each observation moment by using the statistical weighted least squares method to obtain the clock offset coefficient vector of the segment interval.

[0128] Optionally, the steps of determining the satellite clock offset of the first observed satellite and the satellite clock offset of the second observed satellite in each segmented interval based on the clock offset coefficient vector of the segmented interval include: extracting the first clock offset coefficient set of the first observed satellite from the clock offset coefficient vector of the segmented interval; substituting the first clock offset coefficient set into the high-order polynomial of the corresponding segmented interval for calculation to obtain the satellite clock offset of the first observed satellite in the segmented interval; extracting the second clock offset coefficient set of the second observed satellite from the clock offset coefficient vector of the segmented interval; substituting the second clock offset coefficient set into the high-order polynomial of the corresponding segmented interval for calculation to obtain the satellite clock offset of the second observed satellite in the segmented interval.

[0129] Optionally, the steps of preprocessing the inter-satellite link measurement data include: detecting outliers in the inter-satellite link measurement data and removing the detected outliers; smoothing the inter-satellite link measurement data to remove the noise in the data.

[0130] Figure 4 is a hardware structure block diagram of an electronic device (or mobile device) that executes the satellite clock offset determination method based on the inter-satellite link according to an embodiment of the present invention. As Figure 4 shown, the electronic device may include one or more processors ( Figure 4 denoted by 402a, 402b,..., 402n in the figure, and the processor may include, but is not limited to, a processing device such as a microprocessor MCU or a field programmable gate array FPGA), and a memory 404 for storing data. In addition, it may further include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the I / O interface), a network interface, a keyboard, a power supply, and / or a camera. Those of ordinary skill in the art can understand that Figure 4 the structure shown in the figure is only schematic and does not limit the structure of the above-mentioned electronic device. For example, the electronic device may further include more or fewer components than those Figure 4 shown in the figure, or have a different configuration from that Figure 4 shown in the figure.

[0131] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages and disadvantages of the embodiments.

[0132] In the above embodiments of the present invention, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0133] In several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are merely illustrative. For example, the division of the units can be a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some interfaces. The indirect couplings or communication connections of units or modules can be in electrical or other forms.

[0134] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0135] In addition, in each embodiment of the present invention, the functional units can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0136] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: USB flash drives, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), mobile hard disks, magnetic disks, or optical discs and other various media that can store program codes.

[0137] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for determining satellite clock errors based on intersatellite links, characterized in that: include: Acquire intersatellite link measurement data, preprocess the intersatellite link measurement data to obtain intersatellite link data, wherein the intersatellite link data at least includes: observation time, and the observed intersatellite distance between the first observation satellite and the second observation satellite at each of the observation times; Segmenting the intersatellite link data to obtain N segment intervals and intersatellite link data of each segment interval, where N is a positive integer; Calculate the observation residual at each observation time in the segmented interval based on the inter-satellite link data of the segmented interval and the theoretical inter-satellite distance; Based on the observation residuals of each observation time in the segmented interval, the clock error coefficient vector in the segmented interval is calculated by using the statistical weighted least squares method; The satellite clock error of the first observation satellite in each of the segmented intervals and the satellite clock error of the second observation satellite in each of the segmented intervals are determined based on the clock error coefficient vector of the segmented intervals.

2. The method according to claim 1, characterized in that The step of segmenting the intersatellite link data to obtain N segment intervals and the intersatellite link data of each segment interval comprises: Obtaining the observation duration of the entire observation process corresponding to the intersatellite link data; Determine the segment period based on the stability of the onboard clock; The inter-satellite link data is divided based on the observation duration and the segmentation period to obtain N segmentation intervals and the inter-satellite link data of each segmentation interval.

3. The method according to claim 1, characterized in that After segmenting the intersatellite link data, the method further comprises: A high-order polynomial corresponding to the satellite clock error of each segmented interval is established, wherein the high-order polynomial is expressed as: Where a(t) is the satellite clock error in the segmented interval, m represents the mth segmented interval, and i represents the order. It represents the i-th order polynomial coefficient of the satellite clock error in the m-th segment interval, and n represents the highest order of the polynomial.

4. The method according to claim 1, characterized in that: The step of calculating the observation residual at each observation time in the segmented interval based on the inter-satellite link data in the segmented interval and the theoretical inter-satellite distance comprises: Extracting the observed inter-satellite distance at each of the observation moments from the inter-satellite link data of the segmented interval; At each of the observation times, the first observation satellite transmits a signal to the second observation satellite, calculates a first position vector of the first observation satellite at the time of signal transmission based on the ephemeris data of the first observation satellite, and calculates a second position vector of the second observation satellite at the time of signal reception based on the ephemeris data of the second observation satellite; Calculate the theoretical inter-satellite distance at each observation time based on the first position vector and the second position vector; The difference between the observed inter-satellite distance and the theoretical inter-satellite distance at each of the observation moments is calculated to obtain the observation residual at each observation moment in the segmented interval.

5. The method according to claim 1, characterized in that The step of calculating the clock error coefficient vector in the segmented interval by using the statistical weighted least squares method based on the observation residuals of each observation time in the segmented interval includes: The observation equation at each observation moment is established based on the observation residual at each observation moment, wherein the observation equation is expressed as: is the observed residual, represents the clock error coefficient vector of the first observation satellite, represents the clock error coefficient vector of the second observation satellite; The observation equation at each observation moment is fitted and calculated by the statistical weighted least square method to obtain the clock error coefficient vector of the segmented interval.

6. The method according to claim 3, characterized in that The step of determining the satellite clock error of the first observation satellite in each of the segmented intervals and the satellite clock error of the second observation satellite in each of the segmented intervals based on the clock error coefficient vector of the segmented intervals comprises: Extracting a first clock error coefficient set for a first observation satellite from the clock error coefficient vector of the segmented interval; Substituting the first clock error coefficient set into the high-order polynomial of the corresponding segmented interval for calculation, to obtain the satellite clock error of the first observed satellite in the segmented interval; Extracting a second clock error coefficient set for a second observation satellite from the clock error coefficient vector of the segmented interval; Substitute the second clock error coefficient set into the high-order polynomial of the corresponding segmented interval for calculation to obtain the satellite clock error of the second observation satellite in the segmented interval.

7. The method according to claim 1, characterized in that The step of preprocessing the intersatellite link measurement data comprises: Performing outlier detection on the intersatellite link measurement data, and removing the detected outliers; The intersatellite link measurement data is smoothed to remove noise in the data.

8. A satellite clock error determination device based on an intersatellite link, characterized in that: include: an acquisition unit, configured to acquire intersatellite link measurement data, preprocess the intersatellite link measurement data, and obtain intersatellite link data, wherein the intersatellite link data at least includes: an observation time, and an observed intersatellite distance between a first observation satellite and a second observation satellite at each of the observation times; A segmentation unit, used for segmenting the intersatellite link data to obtain N segmentation intervals and the intersatellite link data of each segmentation interval, wherein N is a positive integer; A first calculation unit, configured to calculate the observation residual at each observation time in the segmented interval based on the inter-satellite link data of the segmented interval and the theoretical inter-satellite distance; A second calculation unit is used to calculate the clock error coefficient vector in the segmented interval by using a statistical weighted least square method based on the observation residuals of each observation time in the segmented interval; A determination unit is used to determine the satellite clock error of the first observation satellite in each of the segmented intervals and the satellite clock error of the second observation satellite in each of the segmented intervals based on the clock error coefficient vector of the segmented intervals.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the satellite clock error determination method based on inter-satellite links as described in any one of claims 1 to 7.

10. An electronic device, characterized in that: It includes one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the satellite clock error determination method based on inter-satellite links as described in any one of claims 1 to 7.

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