A space-based directional observation method and device based on orbit accuracy assessment

Abstract

This invention discloses a space-based directional observation method and apparatus based on orbital accuracy assessment. The method includes acquiring stellar angular distance measurement data, Ka-band inter-satellite link observations, and L-band satellite-to-ground link observations from BeiDou satellites. Using this information, a multi-dimensional observation matrix is ​​constructed and processed to obtain satellite position parameters corresponding to three space-based directional observation modes. Using the MGEX precise ephemeris as a baseline, the satellite position parameters are compared to obtain the optimal observation mode. Therefore, this invention proposes three space-based directional observation modes, using orbital accuracy as the evaluation criterion, forming a highly adaptable and practical observation mode system that improves the orbital accuracy of BeiDou satellites.

Description

Technical Field

[0001] This invention relates to the field of satellite navigation technology, and specifically to a space-based orientation observation method and device based on orbit accuracy assessment. Background Technology

[0002] In the field of deep space measurement, it is crucial to explore the integrated application of navigation measurement technology and star sensor-based space-based orientation measurement technology, aiming to solve the challenges of accuracy and coverage in navigation measurements under complex environments. However, due to the immaturity of the specific design of the space-based orientation measurement mode, this integrated technology model is currently still in the exploratory and demonstration stage and requires further research and optimization.

[0003] Space-based orientation measurement, as a technological method that breaks through the limitations of traditional ground-based measurement, provides a novel solution for navigation tasks in complex scenarios. Its core lies in observing target satellites and background stars using high-precision star sensors to obtain inter-satellite orientation information, thereby accurately determining the direction of the line connecting target satellites in inertial space. Simultaneously, combining this with high-precision inter-satellite ranging obtained through inter-satellite links (such as the Ka-band) further optimizes orbital data calculation. These two approaches complement each other, significantly improving the accuracy of navigation satellite orbital data and demonstrating superior performance in estimating orbital orientation elements. However, current research mainly focuses on verifying autonomous orbit determination methods for navigation satellites supported by space-based orientation measurement, primarily concentrating on theoretical feasibility analysis and algorithm correctness verification, without in-depth research on the adaptive design of measurement modes and their practical engineering implementation. This limitation directly restricts the widespread application of space-based orientation measurement technology in engineering practice, while the scientific and rational design of space-based orientation measurement modes is crucial for its effective implementation in complex navigation tasks. Summary of the Invention

[0004] The purpose of this invention is to propose a space-based directional observation method and device based on orbital accuracy assessment to solve the above-mentioned problems.

[0005] To achieve the above objectives, a first aspect of the present invention discloses a space-based directional observation method based on orbital accuracy assessment, the method comprising:

[0006] S1. Acquire stellar angular distance measurement data of BeiDou satellites under three space-based directional observation modes; the three space-based directional observation modes include staring measurement mode, short-period rotation measurement mode, and long-period rotation measurement mode; the stellar angular distance measurement data includes a first-mode stellar angular distance measurement dataset, a second-mode stellar angular distance measurement dataset, and a third-mode stellar angular distance measurement dataset; the stellar angular distance measurement data includes relative right ascension and relative declination data between stars in the celestial coordinate system; preferably, the observation duration is not less than 15 days;

[0007] S2. Use Ka-band inter-satellite links to conduct inter-satellite observations and obtain Ka-band inter-satellite link observation values;

[0008] S3. Use the BeiDou system monitoring station to conduct L-band satellite-to-ground observations and obtain L-band satellite-to-ground link observation values;

[0009] S4. Based on the star angular distance measurement data, Ka-band inter-satellite link observations and L-band satellite-to-ground link observations, construct a multi-dimensional observation matrix and perform calculation processing to obtain the satellite position parameters corresponding to the three space-based directional observation modes.

[0010] S5. Using the MGEX precise ephemeris as a comparison baseline, the satellite position parameters corresponding to the three space-based directional observation modes are compared and processed to obtain the optimal observation mode.

[0011] As an optional implementation, in the first aspect of the present invention, the three space-based directional observation modes specifically include:

[0012] The staring measurement mode includes: using 3 BeiDou IGSO (Inclined Geosynchronous Orbit) satellites to stare at 24 BeiDou MEO (Medium Earth Orbit) satellites; the 24 MEO satellites are distributed in 3 orbital planes, and each IGSO satellite is fixed to observe one visible MEO satellite on a certain orbital plane; when the MEO satellite is not visible, the observation is switched to other visible MEO satellites in the same orbital plane; each IGSO satellite generates one stellar angular distance measurement data at each observation time, and the observation is carried out every 15 minutes to obtain the first mode stellar angular distance measurement dataset.

[0013] The short-cycle rotation measurement mode uses a first duration as the short rotation cycle, which is no less than 1 hour and no more than 2 hours. Within each short rotation cycle, three BeiDou IGSO satellites conduct rotational observations of MEO satellites in three orbits. Each IGSO satellite observes any visible MEO satellite on a fixed orbital plane, and observes once every 15 minutes. At the beginning of the next short rotation cycle, the IGSO satellites switch to another orbital plane, and the three IGSO satellites switch according to the same rules to ensure that MEO satellites participate in the observation of all three orbital planes within each short rotation cycle. Each IGSO satellite selects any visible MEO satellite on the observed orbital plane for observation, and generates one stellar angular distance measurement data at each observation moment, thus obtaining the second-mode stellar angular distance measurement dataset.

[0014] The long-cycle rotation measurement mode uses a second duration as the long rotation cycle, which is no less than 8 hours and no more than 12 hours. Within each long rotation cycle, three BeiDou IGSO satellites conduct rotational observations of MEO satellites in three orbits using star sensors. Each IGSO satellite observes any visible MEO satellite in its fixed observation orbit plane, taking one observation every 15 minutes. At the start of the next long rotation cycle, the IGSO satellites switch to another orbit plane, and the three IGSO satellites switch according to the same rules to ensure that MEO satellites participate in the observation of all three orbit planes within each long rotation cycle. Each IGSO satellite selects any visible MEO satellite in its observed orbit plane for observation, and generates one stellar angular distance measurement data point at each observation moment, thus obtaining the third-mode stellar angular distance measurement dataset.

[0015] As an optional implementation, in the first aspect of the present invention, the step of using Ka-band inter-satellite links for inter-satellite observation to obtain Ka-band inter-satellite link observation values ​​includes:

[0016] Based on the inter-satellite observation link of the BeiDou system's Ka-band, and based on inter-satellite pseudorange observations Extracting inter-satellite link observations The corresponding expression is:

[0017]

[0018] Where c is the speed of light. and These represent the transmit and receive delays of the inter-satellite link device A, respectively. and These represent the transmit and receive delays of the inter-satellite link device B, respectively. and These are error correction terms from inter-satellite observations, including satellite antenna phase center and relativistic effects, both of which can be accurately modeled and corrected using known models. The data sampling interval is set to 15 minutes.

[0019] As an optional implementation, the step of using BeiDou system monitoring stations to conduct L-band satellite-to-ground observations and obtain L-band satellite-to-ground link observation values ​​includes:

[0020] Domestic BeiDou monitoring stations are deployed in Hainan, Beijing, Northeast China, Xinjiang, Fujian, and Sichuan. L-band satellite-to-ground link observations are conducted from these monitoring stations, with a data sampling interval of 15 minutes, yielding t... k The L-band satellite-to-ground link observation values ​​from the time monitoring station are denoted as

[0021] As an optional implementation, in the first aspect of the present invention, the step of constructing a multi-dimensional observation matrix and performing calculation processing based on the stellar angular distance measurement data, Ka-band inter-satellite link observations, and L-band satellite-to-ground link observations to obtain satellite position parameters corresponding to three space-based directional observation modes includes:

[0022] S41. The star angular distance measurement data, Ka-band inter-satellite link observations and L-band satellite-to-ground link observations are integrated and processed to obtain a multi-dimensional observation matrix corresponding to the three space-based directional observation modes.

[0023] The multidimensional observation matrix is ​​represented as follows:

[0024]

[0025] In the formula, t k L represents the observation time. orb (t k ) represents a multidimensional observation matrix. This represents the observation value of the Ka-band inter-satellite link. This represents the L-band satellite-to-ground link observation value. This represents the angular distance measurement data of stars in mode i. The relative right ascension and relative declination of the line connecting inter-satellite observation satellite A and observation satellite B in the celestial coordinate system are respectively represented, and the i-mode is one of the three space-based directional observation modes;

[0026] S42. Based on the multidimensional observation matrix corresponding to the three space-based directional observation modes, construct the multidimensional observation equations corresponding to the three space-based directional observation modes.

[0027] The multi-dimensional observation equation is as follows:

[0028]

[0029] In the formula, L orb (t k ) represents a multidimensional observation matrix, X orb (t k ) represents the epoch t k The position parameters of the BeiDou satellite at time k=1, t k That is, time t1, which is the starting time, and the position parameters X of the Beidou satellite. orb (t1) is the quantity to be estimated, Δ orb Let A be the orbital observation noise vector. orb The satellite position coefficient matrix expresses the relationship between the observed data and the satellite position vector, and can be specifically represented as:

[0030]

[0031] S43. Based on the multi-dimensional observation equations corresponding to the three space-based directional observation modes, the satellite position parameters corresponding to the three space-based directional observation modes are obtained by solving the least squares algorithm.

[0032] The satellite position parameters are expressed as follows:

[0033] X orb (t k )=(A orb T ·A orb ) -1 ·A orb T ·L orb (t k ).

[0034] As an optional implementation, in the first aspect of the present invention, the step of comparing the satellite position parameters corresponding to the three space-based directional observation modes using MGEX precise ephemeris as a comparison baseline to obtain the optimal observation mode includes:

[0035] S51. Obtain the precise ephemeris of the BeiDou satellite from MGEX to obtain the reference satellite position parameter information; the epoch of the reference satellite position parameter information is the same as the epoch of the satellite position parameters corresponding to the three space-based directional observation modes;

[0036] It should be noted that the precise ephemeris of the BeiDou satellites obtained by MGEX refers to the precise ephemeris of the BeiDou satellites released by the Multimode GNSS Experimental Tracking Network International Organization, which is publicly available information.

[0037] S52. Based on the reference satellite position parameter information, perform error calculation processing on the satellite position parameters corresponding to the three space-based directional observation modes to obtain the error values ​​corresponding to the three space-based directional observation modes.

[0038] S53. Based on the error values ​​corresponding to the three space-based directional observation modes, select the space-based directional observation mode corresponding to the error value as the optimal observation mode.

[0039] As an optional implementation, in the first aspect of the present invention, the step of performing error calculation processing on the satellite position parameters corresponding to the three space-based directional observation modes based on the reference satellite position parameter information to obtain the error values ​​corresponding to the three space-based directional observation modes includes:

[0040] S521. Calculate the root mean square error of the difference between the satellite position parameters corresponding to any given sky-based directional observation mode and the reference satellite position parameter information according to the epoch time sequence, and obtain the error value of the given sky-based directional observation mode.

[0041] S522. Repeat step S521 to obtain the error values ​​corresponding to the three space-based orientation observation modes.

[0042] The second aspect of this invention discloses a space-based directional observation device based on orbital accuracy assessment, employing the space-based directional observation method based on orbital accuracy assessment disclosed in the first aspect of this invention. The device includes:

[0043] A stellar angular distance measurement data acquisition module is used to acquire stellar angular distance measurement data information from BeiDou satellites under three space-based directional observation modes: staring measurement mode, short-period rotation measurement mode, and long-period rotation measurement mode; the stellar angular distance measurement data information includes a first-mode stellar angular distance measurement dataset, a second-mode stellar angular distance measurement dataset, and a third-mode stellar angular distance measurement dataset; the stellar angular distance measurement data includes inter-satellite relative right ascension and relative declination data in the celestial coordinate system.

[0044] The Ka-band inter-satellite link observation acquisition module is used to conduct inter-satellite observations using Ka-band inter-satellite links and acquire Ka-band inter-satellite link observation values.

[0045] The L-band satellite-to-ground link observation module is used to conduct L-band satellite-to-ground observations using BeiDou system monitoring stations and obtain L-band satellite-to-ground link observation values.

[0046] The satellite position parameter calculation module is used to construct a multi-dimensional observation matrix and perform calculation processing based on the star angular distance measurement data, Ka-band inter-satellite link observations and L-band satellite-to-ground link observations to obtain the satellite position parameters corresponding to the three space-based directional observation modes.

[0047] The observation mode determination module uses the MGEX precise ephemeris as a comparison baseline to compare and process the satellite position parameters corresponding to the three space-based directional observation modes to obtain the optimal observation mode.

[0048] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0049] This invention discloses a space-based directional observation method and apparatus based on orbit accuracy assessment. Based on the actual on-orbit operation of BeiDou satellites, it proposes three space-based directional observation modes: staring measurement mode, short-period rotation measurement mode, and long-period rotation measurement mode. Using orbit accuracy as the assessment criterion, it forms a highly adaptable and practical observation mode system by systematically planning star sensor layout schemes, dynamically adjusting observation strategies, and fusing inter-satellite link ranging and direction observation data. This significantly improves the accuracy of navigation satellite orbit determination, balances high-precision measurement with resource optimization, and adapts to the needs of different mission scenarios, providing theoretical basis and technical support for high-precision orbit measurement and complex navigation tasks of the BeiDou system.

[0050] (1) Multi-mode design to improve track accuracy adaptability and reliability

[0051] This invention proposes three space-based directional observation modes, which improve the adaptability and accuracy of orbit measurement by flexibly adjusting the observation strategy according to different mission requirements and scenarios. The multi-mode design fully considers high-dynamic scenarios, global coverage requirements, and long-term observation redundancy, enabling the system to stably output high-precision orbit data in complex environments.

[0052] (2) An evaluation method based on precise ephemeris ensures the optimization of the observation mode.

[0053] By using the MGEX precise ephemeris as a benchmark, the position parameters under different observation modes are evaluated for error, and the root mean square error (RMS) is used as the accuracy measure to ensure that the selected observation mode has the highest orbital accuracy. This method provides a systematic means of optimizing observation modes, which not only guarantees the high-precision requirements of BeiDou satellite orbit calculation, but also provides a scientific basis and technical support for future high-precision navigation missions. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of a space-based directional observation method based on orbital accuracy assessment disclosed in an embodiment of the present invention;

[0055] Figure 2 This is a schematic diagram of three space-based directional observation modes disclosed in an embodiment of the present invention;

[0056] Figure 3 This is a schematic diagram illustrating the calculation of a space-based directional observation method based on orbital accuracy assessment disclosed in an embodiment of the present invention;

[0057] Figure 4 This is a schematic diagram of a space-based directional observation device based on orbital accuracy assessment disclosed in an embodiment of the present invention. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] Example 1

[0060] Please see Figure 1 . Figure 1 This is a schematic diagram of a space-based directional observation method based on orbital accuracy assessment disclosed in an embodiment of the present invention. Figure 1 The space-based orientation observation method based on orbital accuracy assessment described herein is applied in management systems, such as local servers or cloud servers used for management, and is not limited in the embodiments of this invention.

[0061] like Figure 1 As shown, the space-based directional observation method based on orbital accuracy assessment disclosed in this embodiment of the invention includes:

[0062] S1. Acquire stellar angular distance measurement data of BeiDou satellites under three space-based directional observation modes; the three space-based directional observation modes include staring measurement mode, short-period rotation measurement mode, and long-period rotation measurement mode; the stellar angular distance measurement data includes a first-mode stellar angular distance measurement dataset, a second-mode stellar angular distance measurement dataset, and a third-mode stellar angular distance measurement dataset; the stellar angular distance measurement data includes relative right ascension and relative declination data between stars in the celestial coordinate system; preferably, the observation duration is not less than 15 days;

[0063] S2. Use Ka-band inter-satellite links to conduct inter-satellite observations and obtain Ka-band inter-satellite link observation values;

[0064] S3. Use the BeiDou system monitoring station to conduct L-band satellite-to-ground observations and obtain L-band satellite-to-ground link observation values;

[0065] S4. Based on the star angular distance measurement data, Ka-band inter-satellite link observations and L-band satellite-to-ground link observations, construct a multi-dimensional observation matrix and perform calculation processing to obtain the satellite position parameters corresponding to the three space-based directional observation modes.

[0066] S5. Using the MGEX precise ephemeris as a comparison baseline, the satellite position parameters corresponding to the three space-based directional observation modes are compared and processed to obtain the optimal observation mode.

[0067] As an optional implementation, please refer to Figure 2 , Figure 2 This is a schematic diagram of three space-based directional observation modes disclosed in an embodiment of the present invention, such as... Figure 2 As shown, the three space-based directional observation modes specifically include:

[0068] The staring measurement mode includes: using 3 BeiDou IGSO (Inclined Geosynchronous Orbit) satellites to stare at 24 BeiDou MEO (Medium Earth Orbit) satellites; the 24 MEO satellites are distributed in 3 orbital planes, and each IGSO satellite is fixed to observe one visible MEO satellite on a certain orbital plane; when the MEO satellite is not visible, the observation is switched to other visible MEO satellites in the same orbital plane; each IGSO satellite generates one stellar angular distance measurement data at each observation time, and the observation is carried out every 15 minutes to obtain the first mode stellar angular distance measurement dataset.

[0069] It should be noted that the staring measurement mode uses a star sensor to conduct long-term continuous observation of specific target satellites, focusing on high-precision data acquisition, which is suitable for orbital accuracy optimization needs in key areas or specific mission scenarios.

[0070] The short-cycle rotation measurement mode uses a first duration as the short rotation cycle, which is no less than 1 hour and no more than 2 hours. Within each short rotation cycle, three BeiDou IGSO satellites use star sensors to perform rotational observations of MEO satellites in three orbits. Each IGSO satellite observes any visible MEO satellite in its fixed observation orbit plane, and observes once every 15 minutes. At the beginning of the next short rotation cycle, the IGSO satellites switch to another orbit plane, and the three IGSO satellites switch according to the same rules to ensure that MEO satellites participate in the observation of all three orbit planes within each short rotation cycle. Each IGSO satellite selects any visible MEO satellite in its observed orbit plane for observation. Each observation moment generates one stellar angular distance measurement data, resulting in the second-mode stellar angular distance measurement dataset.

[0071] In short-period round-robin measurement mode, all orbital planes are dynamically covered, improving the uniformity and efficiency of observations. Dynamic adjustment of the star sensor's observation target balances orbital coverage breadth and measurement data continuity, making it suitable for accuracy assessment in multi-target dynamic scenarios.

[0072] The long-cycle rotation measurement mode uses a second duration as the long rotation cycle, which is no less than 8 hours and no more than 12 hours. Within each long rotation cycle, three BeiDou IGSO satellites conduct rotational observations of MEO satellites in three orbits using star sensors. Each IGSO satellite observes any visible MEO satellite in its fixed observation orbit plane, taking one observation every 15 minutes. At the start of the next long rotation cycle, the IGSO satellites switch to another orbit plane, and the three IGSO satellites switch according to the same rules to ensure that MEO satellites participate in the observation of all three orbit planes within each long rotation cycle. Each IGSO satellite selects any visible MEO satellite in its observed orbit plane for observation, and generates one stellar angular distance measurement data point at each observation moment, thus obtaining the third-mode stellar angular distance measurement dataset.

[0073] It should be noted that the long-cycle rotation measurement mode plans observation tasks with a longer observation cycle, improves global orbit accuracy and consistency through redundant observation, and is suitable for orbit data optimization in global navigation tasks.

[0074] Unlike the short-cycle rotation measurement mode, the long-cycle rotation measurement mode extends the rotation switching interval. Within each rotation cycle, angle measurement observations are performed at 15-minute intervals, generating three angle measurement data points at the same measurement moment. By extending the rotation cycle, this mode is suitable for long-term global observation tasks while reducing the resource consumption caused by frequent switching.

[0075] It should be noted that the stellar angular distance measurement data obtained under the above three space-based directional observation modes vary in accuracy depending on the observation mode, as specifically expressed as follows:

[0076]

[0077] Among them, (x A ,y A ,z A ) and (x B ,y B ,z B The vectors () represent the position vectors of satellite A and satellite B in the inertial coordinate system, respectively. and and These represent the observation errors under the i-th observation mode (approximately on the order of 5mas).

[0078] As an optional implementation, the step of using Ka-band inter-satellite links for inter-satellite observation to obtain Ka-band inter-satellite link observation values ​​includes:

[0079] Based on the inter-satellite observation link of the BeiDou system's Ka-band, and based on inter-satellite pseudorange observations Extracting inter-satellite link observations The corresponding expression is:

[0080]

[0081] Where c is the speed of light. and These represent the transmit and receive delays of the inter-satellite link device A, respectively. and These represent the transmit and receive delays of the inter-satellite link device B, respectively. and These are error correction terms from inter-satellite observations, including satellite antenna phase center and relativistic effects, both of which can be accurately modeled and corrected using known models. The data sampling interval is set to 15 minutes.

[0082] As an optional implementation, the step of using BeiDou system monitoring stations to conduct L-band satellite-to-ground observations and obtain L-band satellite-to-ground link observation values ​​includes:

[0083] Domestic BeiDou monitoring stations are deployed in Hainan, Beijing, Northeast China, Xinjiang, Fujian, and Sichuan. L-band satellite-to-ground link observations are conducted from these monitoring stations, with a data sampling interval of 15 minutes, yielding t... k The L-band satellite-to-ground link observation values ​​from the time monitoring station are denoted as

[0084] The above-mentioned monitoring station's satellite-to-ground link observation data are raw pseudorange phase observation data. After necessary data preprocessing, and using the existing precise navigation measurement model, phase center correction, tropospheric and ionospheric delay error correction, relativistic effect correction, and Earth tidal error correction are achieved for the station antenna and satellite antenna.

[0085] To correct the phase center of a satellite antenna, the calculation requires first transforming the satellite's mechanical coordinate system to the satellite's orbital coordinate system, and then transforming it to the J2000 inertial frame to give the phase center deviation.

[0086] Transforming a satellite from its mechanical coordinate system to its orbital coordinate system requires three coordinate axis rotations. 1) Rotation around the z-axis. s 1) yaw angle of rotation around the axis; 2) yaw angle of rotation around the axis. s 3) Rotation and pitch angle around x s The axis rotation roll angle. The formula for calculating the transformation from the satellite mechanical coordinate system to the satellite orbital coordinate system is as follows:

[0087]

[0088] in It is the position of the antenna phase center in the mechanical coordinate system relative to the origin (geometric center) of the mechanical coordinate system; the three rotation matrices are represented as follows, with the angles being positive when rotating counterclockwise.

[0089]

[0090]

[0091] The three attitude angles (roll, pitch, yaw) are obtained from the telemetry data of the satellite attitude.

[0092] The phase center deviation is given in the satellite reference coordinate system, which is defined as follows: the origin is at the satellite's center of mass, the Z-axis points to the Earth's center of mass, the X-axis represents the satellite's direction of motion, and the Y-axis, Z-axis, and X-axis form a right-handed coordinate system. That is:

[0093]

[0094] in and These are the satellite's position and velocity vectors in the inertial frame, respectively.

[0095] The transformation relationship from the satellite reference coordinate system to the J2000 inertial frame is as follows:

[0096]

[0097] Therefore, the satellite antenna phase center correction ΔD SatAnt The model is:

[0098]

[0099] For relativistic effects, the distance correction ΔD caused by the influence of the periodic term CRel The following formula can be used for calculation:

[0100]

[0101] Among them, X S , denoted as the satellite's position and velocity vectors, respectively, where c is the speed of light.

[0102] For the phase center correction of the station antenna, precise calibration is performed during the manufacturing process of the ground measurement equipment, and the calibration results are provided to the user. Therefore, this error can be corrected using the parameters provided by the manufacturer.

[0103] To correct the tropospheric delay error, actual meteorological observation data from tracking stations are used in the orbit determination calculation. Pseudorange phase observation data are corrected using the Saastamoinen-Neil model. In this model, temperature, air pressure, and humidity are input to calculate the tropospheric delay error.

[0104] To address ionospheric delay error, a dual-frequency ionospheric de-escalation combination is employed. Where f1 and f2 are the frequencies of two points, and L1 and L2 are the pseudorange observations at the two frequencies. (The last part, "L," appears to be a typo and can be omitted.) C Combining these methods can eliminate the influence of ionospheric errors and correct ionospheric errors. Under the condition of only single-frequency observation, the global precision ionospheric delay model provided by the European Orbit Determination Centre (CODE) is used to calculate the ionospheric delay of each monitoring station and the corresponding puncture point of the satellite using the global ionospheric delay map.

[0105] The following formula can be used to calculate the Earth's tidal error:

[0106]

[0107] In the formula, GM is the Earth's gravitational constant; j Let r and R be the gravitational constants of tidal bodies (the Moon when j=2, the Sun when j=3). j These represent the geocentric locations of the observation station and the tidal body, respectively. Let h2 be the corresponding unit vector, h2 be the Love number, and l2 be the Shida number.

[0108] As an optional implementation, based on the stellar angular distance measurement data, Ka-band inter-satellite link observations, and L-band satellite-to-ground link observations, a multi-dimensional observation matrix is ​​constructed and processed to obtain the satellite position parameters corresponding to the three space-based directional observation modes, including:

[0109] S41. The star angular distance measurement data, Ka-band inter-satellite link observations and L-band satellite-to-ground link observations are integrated and processed to obtain a multi-dimensional observation matrix corresponding to the three space-based directional observation modes.

[0110] The multidimensional observation matrix is ​​represented as follows:

[0111]

[0112] In the formula, t k L represents the observation time. orb (t k ) represents a multidimensional observation matrix. This represents the observation value of the Ka-band inter-satellite link. This represents the L-band satellite-to-ground link observation value. This represents the angular distance measurement data of stars in mode i. The relative right ascension and relative declination of the line connecting inter-satellite observation satellite A and observation satellite B in the celestial coordinate system are respectively represented, and the i-mode is one of the three space-based directional observation modes;

[0113] S42. Based on the multidimensional observation matrix corresponding to the three space-based directional observation modes, construct the multidimensional observation equations corresponding to the three space-based directional observation modes.

[0114] The multi-dimensional observation equation is as follows:

[0115]

[0116] In the formula, L orb (t k ) represents a multidimensional observation matrix, X orb (t k ) represents the epoch t k The position parameters of the BeiDou satellite at time k=1, t k That is, time t1, which is the starting time, and the position parameters X of the Beidou satellite. orb (t1) is the quantity to be estimated, Δ orb Let A be the orbital observation noise vector. orb The satellite position coefficient matrix expresses the relationship between the observed data and the satellite position vector, and can be specifically represented as:

[0117]

[0118] It should be noted that the mechanical model used for orbit determination includes the Earth's central gravitational force on the satellite, conservative force perturbations, and non-conservative force perturbations. The conservative force perturbations include N-body perturbations, Earth shape perturbations, solid tides, and ocean tide perturbations. The non-conservative force perturbations include solar direct radiation pressure perturbations, Earth albedo radiation pressure perturbations, and satellite body radiation perturbations. The Earth's gravitational field adopts the 10×10 order JGM-3 model, the planetary ephemeris adopts the JPL DE403 parameters, the nutation model adopts the IAU80 model, the solar radiation pressure model adopts the ECOM5 model, and the solid tides adopt the IERS96 model.

[0119] S43. Based on the multi-dimensional observation equations corresponding to the three space-based directional observation modes, the satellite position parameters corresponding to the three space-based directional observation modes are obtained by solving the least squares algorithm.

[0120] The satellite position parameters are expressed as follows:

[0121] X orb (t k )=(A orb T ·A orb )-1 ·A orb T ·L orb (t k ).

[0122] As an optional implementation, the method of comparing the satellite position parameters corresponding to the three space-based directional observation modes using MGEX precise ephemeris as a comparison baseline to obtain the optimal observation mode includes:

[0123] S51. Obtain the precise ephemeris of the BeiDou satellite from MGEX to obtain the reference satellite position parameter information; the epoch of the reference satellite position parameter information is the same as the epoch of the satellite position parameters corresponding to the three space-based directional observation modes;

[0124] It should be noted that the precise ephemeris of the BeiDou satellites obtained by MGEX refers to the precise ephemeris of the BeiDou satellites released by the Multimode GNSS Experimental Tracking Network International Organization, which is publicly available information.

[0125] S52. Based on the reference satellite position parameter information, perform error calculation processing on the satellite position parameters corresponding to the three space-based directional observation modes to obtain the error values ​​corresponding to the three space-based directional observation modes.

[0126] S53. Based on the error values ​​corresponding to the three space-based directional observation modes, select the space-based directional observation mode corresponding to the error value as the optimal observation mode.

[0127] As an optional implementation, the step of performing error calculation processing on the satellite position parameters corresponding to the three space-based directional observation modes based on the reference satellite position parameter information to obtain the error values ​​corresponding to the three space-based directional observation modes includes:

[0128] S521. Calculate the root mean square error of the difference between the satellite position parameters corresponding to any given sky-based directional observation mode and the reference satellite position parameter information according to the epoch time sequence, and obtain the error value of the given sky-based directional observation mode.

[0129] S522. Repeat step S521 to obtain the error values ​​corresponding to the three space-based orientation observation modes.

[0130] It should be noted that the root mean square error reflects the degree of deviation between the calculated position parameters and the reference precise ephemeris. The smaller the error value, the higher the accuracy of the position parameters.

[0131] It should be noted that the data processing procedure can be found in [reference needed]. Figure 3 , Figure 3 This is a schematic diagram illustrating the calculation of a space-based directional observation method based on orbital accuracy assessment disclosed in an embodiment of the present invention.

[0132] Example 2

[0133] Please see Figure 4 . Figure 4 This is a schematic diagram of a space-based directional observation device based on orbital accuracy assessment, as disclosed in an embodiment of the present invention. Figure 4 The described apparatus can be applied in management systems, such as local servers or cloud servers for management, and the embodiments of the present invention are not limited thereto. Figure 4 As shown, the device may include:

[0134] The stellar angular distance measurement data acquisition module 201 is used to acquire stellar angular distance measurement data information of BeiDou satellites under three space-based directional observation modes; the three space-based directional observation modes include staring measurement mode, short-period rotation measurement mode, and long-period rotation measurement mode; the stellar angular distance measurement data information includes a first-mode stellar angular distance measurement dataset, a second-mode stellar angular distance measurement dataset, and a third-mode stellar angular distance measurement dataset; the stellar angular distance measurement data includes inter-satellite relative right ascension and relative declination data in the celestial coordinate system;

[0135] Ka-band inter-satellite link observation acquisition module 202 is used to conduct inter-satellite observations using Ka-band inter-satellite links and acquire Ka-band inter-satellite link observation values.

[0136] L-band satellite-to-ground link observation acquisition module 203 is used to conduct L-band satellite-to-ground observations using BeiDou system monitoring stations and acquire L-band satellite-to-ground link observation values.

[0137] The satellite position parameter calculation module 204 is used to construct a multi-dimensional observation matrix and perform calculation processing based on the star angular distance measurement data, Ka-band inter-satellite link observations and L-band satellite-to-ground link observations to obtain the satellite position parameters corresponding to the three space-based directional observation modes.

[0138] The observation mode determination module 205 compares and processes the satellite position parameters corresponding to the three space-based directional observation modes using the MGEX precise ephemeris as a comparison baseline to obtain the optimal observation mode.

[0139] This second embodiment is the product embodiment corresponding to the first embodiment. The steps and methods included are the same as those in the first embodiment, and will not be described in detail in the second embodiment.

[0140] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0141] Through the detailed description of the above embodiments, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, including read-only memory (ROM), random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-Erasable Programmable Read-Only Memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0142] Finally, it should be noted that the space-based directional observation method and device based on orbital accuracy assessment disclosed in the embodiments of the present invention are merely preferred embodiments of the present invention and are only used to illustrate the technical solutions of the present invention, not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A space-based directional observation method based on orbital accuracy assessment, characterized in that, The method includes: S1. Acquire stellar angular distance measurement data under three space-based directional observation modes; the three space-based directional observation modes include staring measurement mode, short-period rotation measurement mode, and long-period rotation measurement mode; the stellar angular distance measurement data includes a first-mode stellar angular distance measurement dataset, a second-mode stellar angular distance measurement dataset, and a third-mode stellar angular distance measurement dataset; the stellar angular distance measurement data includes relative right ascension and relative declination data between stars in the celestial coordinate system; S2. Use Ka-band inter-satellite links to conduct inter-satellite observations and obtain Ka-band inter-satellite link observation values; S3. Use the BeiDou system monitoring station to conduct L-band satellite-to-ground observations and obtain L-band satellite-to-ground link observation values; S4. Based on the stellar angular distance measurement data, the Ka-band inter-satellite link observations, and the L-band satellite-to-ground link observations, a multi-dimensional observation matrix is ​​constructed and processed to obtain the satellite position parameters corresponding to the three space-based directional observation modes, including: S41. The star angular distance measurement data, the Ka-band inter-satellite link observations and the L-band satellite-to-ground link observations are integrated and processed to obtain a multi-dimensional observation matrix corresponding to the three space-based directional observation modes. The multidimensional observation matrix is ​​represented as follows: In the formula, Indicates the observation time. Represents a multidimensional observation matrix. This represents the observation value of the Ka-band inter-satellite link. This represents the L-band satellite-to-ground link observation value. This represents the angular distance measurement data of stars in mode i. , The relative right ascension and relative declination represent the direction of the line connecting inter-satellite observation satellite A and observation satellite B in the celestial coordinate system, respectively. The i-mode is one of three space-based directional observation modes. S42. Based on the multidimensional observation matrix corresponding to the three space-based directional observation modes, construct the multidimensional observation equations corresponding to the three space-based directional observation modes. The multi-dimensional observation equation is as follows: In the formula, Represents a multidimensional observation matrix. For the calendar The position parameters of the BeiDou satellite at time k=1 That is The time is the starting time, and the position parameters of the BeiDou satellite. As to be estimated This is the orbital observation noise vector. This is the satellite position coefficient matrix, which expresses the relationship between the observed data and the satellite position vector; S43. Solve the multi-dimensional observation equations corresponding to the three space-based directional observation modes to obtain the satellite position parameters corresponding to the three space-based directional observation modes. The satellite position parameters are expressed as follows: ； S5. Using the MGEX precise ephemeris as a baseline, the satellite position parameters corresponding to the three space-based directional observation modes are compared and processed to obtain the optimal observation mode, including: S51. Obtain the precise ephemeris of the BeiDou satellite from MGEX to obtain the reference satellite position parameter information; the epoch of the reference satellite position parameter information is the same as the epoch of the satellite position parameters corresponding to the three space-based directional observation modes; S52. Based on the reference satellite position parameter information, perform error calculation processing on the satellite position parameters corresponding to the three space-based directional observation modes to obtain the error values ​​corresponding to the three space-based directional observation modes. S53. Based on the error values ​​corresponding to the three space-based directional observation modes, select the space-based directional observation mode with the smallest error value as the optimal observation mode. The three space-based directional observation modes specifically include: The staring measurement mode includes: using 3 BeiDou IGSO satellites to stare at 24 BeiDou MEO satellites; each IGSO satellite fixedly observes one visible MEO satellite in one orbital plane; when the MEO satellite is not visible, it switches to observe other visible MEO satellites in the same orbital plane; each IGSO satellite generates one stellar angular distance measurement data at each observation time, and observes once every 15 minutes to obtain the first mode stellar angular distance measurement dataset; The short-cycle rotation measurement mode uses a first duration as the short rotation cycle, which is not less than 1 hour and not more than 2 hours. Within each short rotation cycle, three BeiDou IGSO satellites conduct rotational observations of MEO satellites in three orbits. Each IGSO satellite is fixed to observe any visible MEO satellite in its orbital plane, and observes once every 15 minutes. At the beginning of the next short rotation cycle, the IGSO satellites switch to another orbital plane. The three IGSO satellites switch according to the same rules to ensure that MEO satellites participate in the observation in all three orbital planes within each short rotation cycle. Each IGSO satellite selects any visible MEO satellite in its observed orbital plane for observation. Each observation moment generates one stellar angular distance measurement data, resulting in the second-mode stellar angular distance measurement dataset. The long-cycle rotation measurement mode uses a second duration as the long rotation cycle, which is no less than 8 hours and no more than 12 hours. Within each long rotation cycle, three BeiDou IGSO satellites conduct rotation observations of MEO satellites in three orbits. Each IGSO satellite is fixed to observe any visible MEO satellite in its orbital plane, and observes once every 15 minutes. At the beginning of the next long rotation cycle, the IGSO satellites switch to another orbital plane, and the three IGSO satellites switch according to the same rules to ensure that MEO satellites participate in the observation of all three orbital planes within each long rotation cycle. Each IGSO satellite selects any visible MEO satellite in its observed orbital plane for observation, and generates one stellar angular distance measurement data at each observation moment, thus obtaining the third-mode stellar angular distance measurement dataset.

2. The space-based directional observation method based on orbital accuracy assessment according to claim 1, characterized in that, The satellite position coefficient matrix Represented as: ； In the formula, , , These represent the coordinates of satellite A in the inertial coordinate system. , , These represent the coordinates of satellite B in the inertial coordinate system.

3. The space-based directional observation method based on orbital accuracy assessment according to claim 1, characterized in that, Based on the reference satellite position parameter information, error calculation processing is performed on the satellite position parameters corresponding to the three space-based directional observation modes to obtain the error values ​​corresponding to the three space-based directional observation modes, including: S521. Calculate the root mean square error of the difference between the satellite position parameters corresponding to any given sky-based directional observation mode and the reference satellite position parameter information according to the epoch time sequence, and obtain the error value of the given sky-based directional observation mode. S522. Repeat step S521 to obtain the error values ​​corresponding to the three space-based orientation observation modes.

4. A space-based directional observation device based on orbital accuracy assessment, characterized in that, The apparatus, applied to the space-based orientation observation method based on orbital accuracy assessment as described in any one of claims 1-3, comprises: A stellar angular distance measurement data acquisition module is used to acquire stellar angular distance measurement data information from BeiDou satellites under three space-based directional observation modes: staring measurement mode, short-period rotation measurement mode, and long-period rotation measurement mode; the stellar angular distance measurement data information includes a first-mode stellar angular distance measurement dataset, a second-mode stellar angular distance measurement dataset, and a third-mode stellar angular distance measurement dataset; the stellar angular distance measurement data includes inter-satellite relative right ascension and relative declination data in the celestial coordinate system. The Ka-band inter-satellite link observation acquisition module is used to conduct inter-satellite observations using Ka-band inter-satellite links and acquire Ka-band inter-satellite link observation values. The L-band satellite-to-ground link observation module is used to conduct L-band satellite-to-ground observations using BeiDou system monitoring stations and obtain L-band satellite-to-ground link observation values. The satellite position parameter calculation module is used to construct a multi-dimensional observation matrix and perform calculation processing based on the star angular distance measurement data, Ka-band inter-satellite link observations and L-band satellite-to-ground link observations to obtain the satellite position parameters corresponding to the three space-based directional observation modes. The observation mode determination module is used to compare and process the satellite position parameters corresponding to the three space-based directional observation modes with MGEX precise ephemeris as the comparison baseline, and obtain the optimal observation mode.

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