WO2020228754A1 - 一种低轨卫星定轨方法、装置及系统 - Google Patents

一种低轨卫星定轨方法、装置及系统 Download PDF

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Publication number
WO2020228754A1
WO2020228754A1 PCT/CN2020/090127 CN2020090127W WO2020228754A1 WO 2020228754 A1 WO2020228754 A1 WO 2020228754A1 CN 2020090127 W CN2020090127 W CN 2020090127W WO 2020228754 A1 WO2020228754 A1 WO 2020228754A1
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orbit
satellite
navigation satellite
low
ground system
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PCT/CN2020/090127
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English (en)
French (fr)
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王军
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北京合众思壮科技股份有限公司
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/38—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
    • G01S19/39—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/40—Correcting position, velocity or attitude
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/38—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system
    • G01S19/39—Determining a navigation solution using signals transmitted by a satellite radio beacon positioning system the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/42—Determining position
    • G01S19/45—Determining position by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement
    • G01S19/46—Determining position by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement the supplementary measurement being of a radio-wave signal type

Definitions

  • This application relates to the technical field of satellite communication, and in particular to a method, device and system for determining the orbit of a low-orbit satellite.
  • GNSS Global Navigation Satellite System
  • GNSS observation data includes pseudorange observations and carrier phase observations.
  • the broadcast ephemeris is used to determine the position and clock error of the navigation satellite, and then the position of the low-orbit satellite is determined according to the position, clock error and observation data of the navigation satellite.
  • embodiments of the present application provide a satellite orbit determination method, device, and system to improve the accuracy of satellite orbit determination.
  • the first aspect of the embodiments of the present application provides a method for determining the orbit of a low-orbit satellite.
  • the method is applied to the low-orbit satellite, and the method includes:
  • the correction information is calculated by the ground system according to the position of the ground system, the observation data of the navigation satellite, and the broadcast ephemeris.
  • the positioning information includes the orbit and clock offset of the navigation satellite
  • the correction information includes the orbit correction number and the clock offset correction number of the navigation satellite
  • the corrected positioning information includes the corrected Orbit and corrected clock difference.
  • the orbit correction number is obtained by the ground system according to the real-time precision orbit of the navigation satellite and the orbit of the navigation satellite;
  • the real-time precise orbit of the navigation satellite is obtained by the ground system according to the position of the ground system, the observation data and the broadcast ephemeris;
  • the orbit of the navigation satellite is obtained by the ground system according to the broadcast ephemeris;
  • the clock error correction number is obtained by the ground system according to the real-time precision clock error of the navigation satellite and the clock error of the navigation satellite;
  • the real-time precision clock offset of the navigation satellite is obtained by the ground system according to the observation data and the real-time precision orbit;
  • the clock offset of the navigation satellite is obtained by the ground system according to the broadcast ephemeris.
  • the using the corrected orbit, the corrected clock difference, and the observation data to determine the orbit of the low-orbit satellite includes:
  • the orbit of the low-orbit satellite is determined according to the orbit parameters of the low-orbit satellite in preset directions.
  • the method before the correction information based on the positioning information acquired and sent by the ground system, the method further includes:
  • the method before correcting the positioning information, the method further includes:
  • the integrity information includes a mark indicating whether the correction information is available
  • a method for determining the orbit of a low-orbit satellite is provided.
  • the method is applied to a ground system, and the method includes:
  • the correction information of the navigation satellite is obtained; the correction information is used for the low-orbit satellite to correct the positioning information to obtain the corrected positioning information; the corrected positioning The information and the observation data of the navigation satellite obtained by the low orbit satellite are used for real-time orbit determination by the low orbit satellite.
  • the correction information includes the orbit correction number and the clock error correction number of the navigation satellite; the positioning information includes the orbit and clock error of the navigation satellite, and the corrected positioning information includes the corrected position information. Orbit and corrected clock difference.
  • the obtaining the correction information of the navigation satellite according to the position of the ground system, the observation data and the broadcast ephemeris includes:
  • the clock error correction number of the navigation satellite is obtained.
  • the obtaining the real-time precise orbit of the navigation satellite according to the position of the ground system, the observation data, and the broadcast ephemeris includes:
  • the positioning information is obtained by the low-orbit satellite according to the obtained broadcast ephemeris of the navigation satellite.
  • the method further includes:
  • the integrity information is obtained according to the correction information, and the integrity information includes a flag indicating whether the correction information is available.
  • a low-orbit satellite orbit determination system includes: a ground system and a low-orbit satellite;
  • the ground system is used to execute the method described in the first aspect
  • the low-orbit satellite is used to perform the method described in the second aspect.
  • a low-orbit satellite orbit determination device which is applied to the low-orbit satellite, and the device includes:
  • the first acquisition unit is used to acquire the broadcast ephemeris and observation data of the navigation satellite;
  • a correction unit configured to obtain positioning information according to the broadcast ephemeris, and correct the positioning information based on the correction information of the positioning information acquired and sent by the ground system;
  • the first calculation unit is used to determine the orbit of the low-orbit satellite using the corrected positioning information and the observation data.
  • the correction information is calculated by the ground system according to the position of the ground system, the observation data of the navigation satellite, and the broadcast ephemeris.
  • the positioning information includes the orbit and clock offset of the navigation satellite
  • the correction information includes the orbit correction number and the clock offset correction number of the navigation satellite
  • the corrected positioning information includes the corrected Orbit and corrected clock difference.
  • the orbit correction number is obtained by the ground system according to the real-time precision orbit of the navigation satellite and the orbit of the navigation satellite;
  • the real-time precise orbit of the navigation satellite is obtained by the ground system according to the position of the ground system, the observation data and the broadcast ephemeris;
  • the orbit of the navigation satellite is obtained by the ground system according to the broadcast ephemeris;
  • the clock error correction number is obtained by the ground system according to the real-time precision clock error of the navigation satellite and the clock error of the navigation satellite;
  • the real-time precision clock offset of the navigation satellite is obtained by the ground system according to the observation data and the real-time precision orbit;
  • the clock offset of the navigation satellite is obtained by the ground system according to the broadcast ephemeris.
  • the first calculation unit includes:
  • the first acquisition subunit is configured to perform filtering calculation according to the corrected orbit, the corrected clock offset, and the observation data to obtain orbit parameters of the low-orbit satellite in preset directions;
  • the first calculation subunit is used to calculate the sum of the variances of the orbit parameters of the low-orbit satellite in preset directions;
  • the first determining subunit is configured to determine the orbital parameters of the low-orbit satellite in the preset directions when the sum of the variances of the orbital parameters in the preset directions is less than the preset threshold. Describe the orbit of a low-orbiting satellite.
  • the device further includes:
  • the first judgment unit is used to judge whether the time information of the positioning information and the correction information match
  • the correction unit is specifically configured to use the correction information to correct the positioning information when the judgment result of the first judgment unit is a match.
  • the device further includes:
  • the second judgment unit is configured to judge whether the correction information is available according to the integrity information acquired and sent by the ground system; the integrity information includes a mark indicating whether the correction information is available;
  • the correction unit is specifically configured to correct the positioning information when the judgment result of the second judgment unit is that the correction information is available.
  • the fifth aspect of the embodiments of the present application provides a low-orbit satellite orbit determination device, which is applied to a ground system, and includes:
  • the second acquisition unit is used to acquire observation data and broadcast ephemeris of navigation satellites
  • the second calculation unit is used to obtain the correction information of the navigation satellite according to the position of the ground system, the observation data and the broadcast ephemeris; the correction information is used for the low-orbit satellite to correct the positioning information to obtain the corrected positioning information
  • the corrected positioning information and the observation data of the navigation satellite obtained by the low-orbit satellite are used for real-time orbit determination of the low-orbit satellite.
  • the correction information includes the orbit correction number and the clock error correction number of the navigation satellite; the positioning information includes the orbit and clock error of the navigation satellite, and the corrected positioning information includes the corrected position information. Orbit and corrected clock difference.
  • the second calculation unit includes:
  • the second calculation subunit is used to obtain the real-time precise orbit of the navigation satellite according to the position of the ground system, the observation data and the broadcast ephemeris;
  • the third calculation subunit is configured to obtain the orbit of the navigation satellite according to the broadcast ephemeris
  • a fourth calculation subunit configured to obtain the orbit correction number of the navigation satellite according to the real-time precision orbit and the orbit of the navigation satellite;
  • a fifth calculation subunit configured to obtain the real-time precision clock offset of the navigation satellite according to the observation data and the real-time precision orbit;
  • the sixth calculation subunit is used to obtain the clock offset of the navigation satellite according to the broadcast ephemeris;
  • the seventh calculation subunit is configured to obtain the clock error correction number of the navigation satellite according to the real-time precision clock error and the clock error of the navigation satellite.
  • the second calculation subunit includes:
  • the second determining subunit is configured to obtain the orbit of the navigation satellite according to the broadcast ephemeris to determine the initial value of the orbit of the navigation satellite;
  • the third determining subunit is configured to correct the initial value of the navigation satellite orbit according to the position of the ground system and the observation data, and determine the corrected navigation satellite orbit as the real-time precision of the navigation satellite track.
  • the positioning information is obtained by the low-orbit satellite according to the obtained broadcast ephemeris of the navigation satellite.
  • the device further includes:
  • the third obtaining unit is configured to obtain integrity information according to the correction information, and the integrity information includes a mark of whether the correction information is available.
  • the low-orbit satellite in the embodiment of the application first obtains the broadcast ephemeris and observation data of the navigation satellite, and calculates the positioning information of the navigation satellite according to the broadcast ephemeris. Then, the correction information of the positioning information sent by the ground system is received, and the positioning information is corrected to obtain the corrected positioning information. Finally, the revised positioning information and observation data are used to determine the orbit of the low-orbiting satellite. It can be seen that the embodiment of the present application introduces the correction information of the positioning information, and uses the corrected positioning information to determine the orbit of the low-orbit satellite to improve the accuracy of the orbit determination.
  • FIG. 1 is an example scene diagram of low-orbit satellite orbit determination provided by an embodiment of the application
  • FIG. 2 is a flowchart of a method for determining the orbit of a low-orbit satellite according to an embodiment of the application
  • FIG. 3 is a flowchart of another low-orbit satellite orbit determination method provided by an embodiment of the application.
  • FIG. 4 is a flowchart of another method for determining the orbit of a low-orbit satellite according to an embodiment of the application
  • 5 is a framework diagram of a low-orbit satellite orbit determination provided by an embodiment of the application.
  • FIG. 6 is a structural diagram of a low-orbit satellite orbit determination system provided by an embodiment of the application.
  • FIG. 7 is a structural diagram of a low-orbit satellite orbit determination device provided by an embodiment of the application.
  • FIG. 8 is a structural diagram of another low-orbit satellite orbit determination device provided by an embodiment of the application.
  • low-orbit satellites use inaccurate reference information (navigation satellite orbits and clock differences) for real-time orbit determination, which affects the accuracy of low-orbit satellites.
  • the embodiments of the present application provide a low-orbit satellite orbit determination method, specifically, the low-orbit satellite obtains the positioning information of the navigation satellite by using the broadcast ephemeris sent by the navigation satellite, and receives the correction information of the positioning information sent by the ground system , To correct the positioning information to obtain the corrected positioning information. Then use the corrected positioning information and observation data to determine the orbit of the low-orbiting satellite. That is, accurate positioning information is used to determine the orbit of the low-orbit satellite, thereby improving the accuracy of the low-orbit satellite.
  • FIG. 1 is an example diagram of a low-orbit satellite orbit determination application scenario provided by an embodiment of this application.
  • it may include ground systems and low-orbit satellites.
  • the ground system can obtain real-time navigation satellite observation data and broadcast ephemeris through the global GNSS tracking station, and obtain correction information about the navigation satellite based on the position, observation data and broadcast ephemeris calculation of the ground system, and send the correction information to Low-orbit satellite.
  • the low-orbit satellite corrects the positioning information of the navigation satellite obtained by its own calculation according to the correction information, and obtains the corrected positioning information.
  • the low-orbit satellite determines its orbit based on the corrected positioning information and observation data.
  • the correction information needs to be updated frequently. Because the low-orbit satellites are running fast, the trajectories of the sub-satellite points are all over the world. If the ground system directly communicates with the low-orbit satellites, the ground system needs to be able to communicate with the low-orbit satellites in many places around the world for a short time, which will take up a lot Communication resources. Therefore, in a possible implementation manner in this embodiment, the communication satellite is used as a relay station between the ground system and the low-orbit satellite to forward data.
  • the low-orbit satellite in the embodiment of this application corrects the positioning information of the navigation satellite obtained by its calculation according to the correction information provided by the ground system.
  • the application will be first described below. The method for determining the correction information in the ground system is explained.
  • FIG. 2 is a flowchart of a method for determining the orbit of a low-orbit satellite according to an embodiment of the application. As shown in FIG. 2, the method is applied to a ground system, and the method may include:
  • S201 Obtain observation data and broadcast ephemeris of navigation satellites.
  • the ground system can obtain GNSS observation data and broadcast ephemeris in real time through a global GNSS tracking station.
  • each GNSS tracking station can be equipped with a GNSS receiver to obtain GNSS observation data and broadcast ephemeris through the GNSS receiver.
  • the GNSS observation data is obtained by the ground system by analyzing the satellite signals sent by the navigation satellites.
  • the observation data may include information such as carrier phase observation values, pseudorange observation values and so on.
  • the carrier phase observation value refers to the instantaneous carrier phase value at the moment when the GNSS receiver receives the carrier signal of the navigation satellite;
  • the pseudorange refers to the signal with a structure of "pseudorandom noise code" transmitted by the navigation satellite according to the on-board clock, called Ranging code signal (ie coarse code C/A code or fine code P code).
  • the ranging code signal is transmitted from the navigation satellite for a time ⁇ t, and then arrives at the receiver antenna; multiplying the above signal propagation time ⁇ t by the electromagnetic wave velocity c in vacuum is the distance from the satellite to the receiver.
  • the propagation time ⁇ t contains the error of the satellite clock and the receiver clock not being synchronized, the satellite ephemeris error, the receiver measurement noise and the delay error of the ranging code propagation in the atmosphere, etc., the distance value obtained from this is not true
  • the geometric distance of the station star is called "pseudorange".
  • the broadcast ephemeris is the radio signal sent by the navigation satellite carrying the message information predicting the number of satellites within a certain period of time, which can be used to calculate the orbit, that is, the position of the navigation satellite.
  • S202 Obtain correction information of the navigation satellite according to the position, observation data and broadcast ephemeris of the ground system.
  • the correction information of the navigation satellite can be calculated according to the position, observation data and broadcast ephemeris of the ground system.
  • the correction information is used for the low-orbit satellite to correct the positioning information to obtain the corrected positioning information
  • the corrected positioning information and the observation data of the navigation satellite obtained by the low-orbit satellite are used for real-time orbit determination of the low-orbit satellite.
  • the positioning information is obtained by the low-orbit satellites according to the acquired broadcast ephemeris of the navigation satellites.
  • the correction information can include the orbit correction number and the clock error correction number of the navigation satellite
  • the positioning information can include the orbit and clock error of the navigation satellite.
  • the corrected positioning information includes the corrected orbit and the corrected clock error.
  • the orbit correction number is used for the low-orbit satellite to correct the orbit of the navigation satellite to obtain the corrected orbit
  • the clock error correction number is used for the low-orbit satellite to correct the clock error of the navigation satellite to obtain the corrected clock error .
  • Low-orbit satellites use the corrected orbit, the corrected clock offset, and the observation data for real-time orbit determination.
  • the orbit of the navigation satellite and the clock difference of the navigation satellite are obtained by the low-orbit satellite according to the broadcast ephemeris of the navigation satellite obtained by the low-orbit satellite.
  • the ground system calculates the orbit correction number and clock error correction number of the navigation satellite according to the position, observation data and broadcast ephemeris of the ground system, and the use of the orbit correction number and clock error for the low-orbit satellite
  • the correction number corrects the orbit and clock difference of the navigation satellite, and the specific realization of orbit determination based on the corrected orbit, the corrected clock difference and the observation data will be described in subsequent embodiments.
  • the communication satellite between the low-orbit satellite and the ground system can be used for forwarding. That is, the ground system transmits the orbit correction number and the clock error correction number to the communication satellite to transmit the orbit correction number and the clock error correction number to the low-orbit satellite through the communication satellite. That is, the communication satellite is used to forward the orbit correction number and the clock error correction number sent by the ground system to the low-orbit satellite to ensure the real-time nature of the orbit correction number and the clock error correction number.
  • the ground system can obtain the correction information of the navigation satellite according to its own position information, the observation data of the navigation satellite, and the calculation of the broadcast ephemeris, so as to send the correction information to the low-orbit satellite, so that the low-orbit satellite uses the correction information to use
  • the positioning information of the navigation satellite obtained by the calculation of the broadcast ephemeris is corrected to obtain the corrected positioning information, and then the orbit determination is performed according to the corrected positioning information and the observation data to improve the orbit determination accuracy.
  • FIG. 3 is a flowchart of a method for obtaining orbit correction numbers and clock offset correction numbers according to an embodiment of the application. As shown in FIG. 3, the method is applied to a ground system, and the method may include:
  • S301 Obtain the real-time precise orbit of the navigation satellite based on the position of the ground system, observation data and broadcast ephemeris.
  • the ground system uses the position, observation data and broadcast ephemeris calculation of the ground system to obtain the real-time precise orbit of the navigation satellite.
  • the orbit of the navigation satellite is determined as the real-time precision orbit of the navigation satellite.
  • the position of the ground system is known and accurate, that is, the position of the GNSS receiver is known and accurate, and the GNSS observation data represents the distance between the GNSS receiver and the navigation satellite, so it can be based on the position and observation of the ground system
  • the data is calculated to obtain a more accurate position of the navigation satellite.
  • the broadcast ephemeris is used to calculate the position of the navigation satellite, there is a certain error in the determined position of the navigation satellite due to the error of the broadcast ephemeris itself.
  • the position of the navigation satellite obtained through the observation data is used to correct the position of the navigation satellite obtained through the broadcast ephemeris, so as to obtain the accurate position of the navigation satellite, that is, the real-time precision orbit.
  • the least squares batch processing method can be used to calculate the real-time precise orbit of the navigation satellite. Specifically, (1) use the broadcast ephemeris to calculate the orbit of the navigation satellite and use it as the initial value of the orbit; (2) wait for the global GNSS When the observation data obtained by the tracking station has accumulated to a certain length of time, the least squares batch processing method is used to iteratively update the initial value of the orbit until the residual sum of the observation value is less than the preset limit. Among them, the residual of the observation can be the residual between the actual position of the ground system and the estimated value.
  • the observation data obtained by the GNSS tracking station also has a certain degree of error.
  • multiple sets of observation data are used for the navigation satellite The position has been revised several times.
  • the specific implementation is to first use the actual position value of the ground system and the first set of observation data to correct the position of the navigation satellite obtained by the broadcast ephemeris to obtain the first position. Then use the first position and the observation data to calculate the estimated value of the ground system position, and obtain the first residual according to the actual position of the ground system and the estimated value of the ground system position. If the first residual meets the preset threshold, it means that the first residual One location is accurate.
  • the actual position value of the ground system and the second set of observation data are used to correct the first position to obtain the second position. Then use the second position and the observation data to calculate the estimated value of the ground system position, and obtain the second residual according to the actual value of the ground system position and the estimated value of the ground system position. If the root mean square of the first residual and the second residual is Satisfying the preset threshold indicates that the second position is accurate. If the root mean square of the first residual and the second residual does not meet the preset threshold, the actual position value of the ground system and the third set of observation data are used to correct the second position to obtain the third position.
  • the third position and the observation data use the third position and the observation data to calculate the estimated value of the ground system position, and obtain the third residual according to the actual value of the ground system position and the estimated value of the ground system position. If the root mean square of the second residual and the third residual is Satisfying the preset threshold value indicates that the third position is accurate. If the root mean square of the second residual and the third residual does not meet the preset threshold, continue to use other sets of observation data to iteratively update until the roots of the two adjacent residuals meet the preset threshold.
  • the orbit correction number for the navigation satellite can be obtained according to the real-time precision orbit and the orbit of the navigation satellite.
  • S304 Obtain the real-time precision clock offset of the navigation satellite based on the observation data and the real-time precision orbit.
  • the ground system calculates and obtains the real-time precision clock error of the navigation satellite according to the real-time precision orbit and observation data, and calculates the clock error of the navigation satellite by using the broadcast ephemeris.
  • the real-time precision clock error of the navigation satellite is obtained by using observation data
  • the real-time precision orbit can be used as a constraint condition to calculate and obtain the real-time precision clock error of the navigation satellite.
  • the clock error correction number of the navigation satellite is obtained according to the real-time precision clock error and the clock error of the navigation satellite.
  • the ground system can obtain the integrity information based on the correction information while calculating the correction information.
  • the integrity information may include a mark indicating whether the correction information is available, so that the low-orbit satellites
  • the integrity monitoring system in the ground system can judge the correction information, and then give a mark as to whether the correction information is available or unavailable according to the judgment result, and then the ground system uses the integrity information to make the correction information available or unavailable.
  • the unavailable flags are sent to low-orbiting satellites.
  • the ground system sends the integrity information to the low-orbit satellite through the communication satellite, so that the low-orbit satellite can determine whether to use the orbit correction data according to the integrity information. It is corrected with the clock correction number to ensure the real-time nature of the integrity information acquired by the low-orbit satellite.
  • the ground system can first send the orbit correction number and clock error correction number to the satellite uploading station, and then the satellite uploading station uploads the orbit correction number, clock error correction number, and integrity information to the communication satellite.
  • the communication satellite receives the orbit correction number and the clock error correction number and sends it to the low-orbit satellite.
  • the ground system can provide low-orbit satellites with orbit correction numbers and clock correction numbers.
  • the low-orbit satellites determine their orbits according to the parameters sent by the navigation satellites, they can first use the orbit correction numbers and clock correction numbers.
  • the orbit and clock difference of the navigation satellite obtained by the calculation of the broadcast ephemeris are corrected so as to use the more accurate orbit and clock error of the navigation satellite to determine its own orbit to improve the accuracy of orbit determination.
  • FIG. 4 is a flowchart of a low-orbit satellite orbit determination method provided by an embodiment of the application. As shown in FIG. 4, the method is applied to a low-orbit satellite, and the method may include:
  • S402 Obtain positioning information according to the broadcast ephemeris, and correct the positioning information based on the correction information of the positioning information acquired and sent by the ground system.
  • the low-orbit satellite can receive the broadcast ephemeris sent by the navigation satellite, obtain positioning information according to the broadcast ephemeris, and receive the correction information of the positioning information sent by the ground system, so as to correct the positioning information by using the correction information to obtain The revised positioning information.
  • the correction information is calculated by the ground system based on the position of the ground system, the observation data of the navigation satellite, and the broadcast ephemeris. For the acquisition of the correction information, please refer to the first embodiment of the method.
  • the positioning information may include the orbit and clock offset of the navigation satellite
  • the correction information includes the orbit correction number and the clock offset correction number of the navigation satellite
  • the corrected positioning information may include the corrected orbit and the corrected clock offset.
  • the acquisition of the orbit correction number and the clock error correction number can refer to method embodiment two.
  • low-orbit satellites can be installed with GNNS receivers to obtain real-time broadcast ephemeris and GNSS observation data of navigation satellites using GNSS receivers.
  • GNSS observation data is obtained by low-orbit satellites by analyzing satellite signals sent by navigation satellites.
  • S403 Use the corrected positioning information and observation data to determine the orbit of the low-orbit satellite.
  • the corrected positioning information and observation data are used to determine the orbit of the low-orbit satellite.
  • the positioning information can include the orbit and clock offset of the navigation satellite
  • the correction information can include the orbit correction number and the clock offset correction number of the navigation satellite
  • the corrected orbit and the corrected clock offset and observation data can be used. Orbit determination of low-orbit satellites. Among them, the specific implementation of using the corrected orbit, the corrected clock difference and the observation data to determine the orbit of the low-orbit satellite will be described in subsequent embodiments.
  • the low-orbit satellites obtain the broadcast ephemeris and observation data of the navigation satellites, calculate the positioning information of the navigation satellites according to the broadcast ephemeris, and at the same time receive the correction information of the positioning information sent by the ground system, and perform the positioning information Correction to obtain the corrected positioning information. Then use the corrected positioning information and observation data to determine the orbit of the low-orbiting satellite.
  • the embodiment of the present application introduces the correction information of the positioning information obtained by the ground system, and uses the corrected positioning information to determine the orbit of the low-orbit satellite, thereby improving the accuracy of the orbit determination.
  • the orbit correction number is obtained by the ground system according to the real-time precision orbit of the navigation satellite and the orbit of the navigation satellite;
  • the real-time precision orbit of the navigation satellite is obtained by the ground system according to the position of the ground system , Observation data and broadcast ephemeris;
  • the orbit of the navigation satellite is obtained by the ground system according to the broadcast ephemeris;
  • the clock correction number is obtained by the ground system according to the real-time precision clock error of the navigation satellite and the clock error of the navigation satellite ;
  • the real-time precision clock error of the navigation satellite is obtained by the ground system based on observation data and real-time precision orbit;
  • the clock error of the navigation satellite is obtained by the ground system based on the broadcast ephemeris.
  • a communication satellite receiver can be installed on a low-orbit satellite, so that the communication satellite receiver can be used to receive the orbit correction number and clock correction number forwarded by the communication satellite.
  • low-orbit satellites can be equipped with integrated receiving equipment capable of receiving both navigation satellite signals and communication satellite signals, or multiple independent equipment for receiving different signals.
  • the orbit correction number and the clock offset correction number the corrected orbit and the corrected clock error of the navigation satellite can be calculated by the following formula:
  • R/T/N are the radial/tangential/normal components of the satellite orbit
  • [R T N] precise is the recovered high-precision real-time orbit
  • [R T N] brdc is the broadcast
  • [dR dT dN] SSR-orbit is the correction number of the orbit in the three directions of R/T/N.
  • dt precise is the recovered high-precision real clock difference
  • dt brdc is the clock difference of the navigation satellite calculated by the broadcast ephemeris
  • dt SSR-clock is the clock correction number.
  • the three directions of R/T/N can also be replaced with X/Y/Z directions, just multiply by the corresponding rotation matrix, and the right side of the equation uses the "+" or "-" sign, and correction The calculation method is related.
  • the low-orbit satellite receives the broadcast ephemeris sent by the navigation satellite and obtains observation data, calculates the orbit and clock difference of the navigation satellite according to the broadcast ephemeris, and receives the orbit correction of the navigation satellite obtained and sent by the ground system. Correct the number and the clock difference. Then use the orbit correction number to correct the orbit of the navigation satellite calculated according to the broadcast ephemeris, and use the clock correction number to correct the clock error of the navigation satellite calculated according to the broadcast ephemeris to obtain the corrected orbit and The corrected clock difference. Then, the orbit and speed of the low-orbit satellite are determined according to the corrected orbit of the navigation satellite, the corrected clock difference and the observation data.
  • the embodiment of the application introduces the orbit correction number and the clock error correction number, thereby improving the overall accuracy of the navigation satellite orbit and clock error, and further improves the positioning when positioning the orbit of the low-orbit satellite according to the orbit and clock error of the navigation satellite. Track accuracy.
  • the variance of the orbit parameter is combined And judge whether the filtering is convergent. If the filtering equation converges, it indicates that the current orbit determination results of low-orbit satellites are reliable.
  • filtering calculation is performed according to the corrected orbit, the corrected clock difference and the observation data to obtain the orbit parameters of the low-orbit satellite in preset directions; and the calculation of the orbital parameters of the low-orbit satellite in the preset directions
  • the sum of variances when the sum of the variances of the orbit parameters of the low-orbit satellite in preset directions is less than the preset threshold, determine the orbit of the low-orbit satellite according to the orbit parameters of the low-orbit satellite in the preset directions .
  • the corrected orbit, the corrected clock error, and the observation data are input into the filter equation.
  • the filter equation may be a Kalman filter equation.
  • the initial value of the state parameter and the initial value of the covariance matrix can be preset for the filter equation.
  • the covariance matrix is used to represent the position error of the low-orbit satellite in three directions, and then use the corrected orbit to correct
  • the initial state parameters and the covariance matrix are updated, when the sum of the position variances of the low-orbiting satellites in the three directions in the updated covariance matrix is less than the preset threshold, it means that the filtering has converged.
  • the orbit parameter of the low-orbit satellite output at this time is determined as the position of the low-orbit satellite.
  • the filtering algorithm can be an extended Kalman filter based on UD decomposition, using satellite-borne GNSS observations, the corrected orbit of the navigation satellite and the corrected clock error as input, and continuous filtering until the Kalman filter converges.
  • the low-orbit satellite can judge Whether the time information of the positioning information and the time information of the correction information match, if they match, the correction information is used to correct the positioning information.
  • the ground system when the ground system calculates and obtains the correction information, it can add a time stamp to the correction information, and the time corresponding to the time stamp is the time when the positioning information can be corrected using the correction information; the low-orbit satellite is acquiring At the same time as the positioning information, a time stamp is added, and the time corresponding to the time stamp is the time specified for obtaining the positioning information.
  • the low-orbit satellite After the low-orbit satellite receives the correction information sent by the ground system, it can judge whether the two match according to the time stamp in the correction information and the time stamp of the positioning information. If they match, the positioning information is corrected.
  • the two match may be that the time stamps of the two are equal, or the time difference between the two is within the preset time range.
  • the IODE value of each satellite provided in the broadcast ephemeris can be used to match the value of each orbit correction number and the additional IODE value of the clock error correction number. If the values are equal, the orbit correction number is used to match the broadcast satellite. The orbit calculated by the calendar is corrected, and the clock difference calculated by the broadcast ephemeris is corrected using the clock correction number.
  • the ground system before the ground system uses the correction information to correct the positioning information, it can also determine whether the received correction information is available, so as to avoid using unavailable correction information to correct the positioning information. , Affecting the accuracy of orbit determination. Specifically, the low-orbit satellite judges whether the correction information is available based on the integrity information acquired and sent by the ground system; the integrity information includes a mark indicating whether the correction information is available. If the correction information is available, the positioning information is corrected. That is, if the integrity information includes a mark that can be used for the correction information, the positioning information is corrected using the correction information; if the integrity information includes a mark that the correction information is not available, the positioning information is not corrected.
  • FIG. 5 is a low-orbit satellite orbit determination framework provided by an embodiment of this application.
  • the low-orbit satellite is equipped with a GNSS receiver to obtain satellite-borne GNSS observation data and is sent by navigation satellites. Broadcast ephemeris and orbit corrections and clock corrections sent by ground systems. Then, the corrected orbit of the navigation satellite is calculated, that is, the actual orbit and the corrected clock difference, that is, the actual clock difference. Then calculate the orbit and speed of the low-orbit satellite based on the actual orbit of the navigation satellite, the actual clock difference and the GNSS observation data. Kalman filtering is performed on the calculated orbit and velocity of the low-orbit satellite.
  • the filtering converges, indicating that the orbit determination result is reliable, the result is output. If it does not converge, no results are output.
  • the dynamic model is used to predict the position and velocity information of the low-orbit satellite at the next time as the prior value of the filtering parameters at the next time, and filtering is performed again. Cycle in turn.
  • this application also provides a low-orbit satellite orbit determination system, which will be described below with reference to the accompanying drawings.
  • FIG. 6 is a structural diagram of a low-orbit satellite orbit determination system provided by an embodiment of the application. As shown in FIG. 6, the system may include:
  • It may include a ground system 601 and a low-orbit satellite 602.
  • the ground system 601 is configured to execute the methods described in method embodiment one and method embodiment two;
  • the LEO satellite 602 is used to execute the method described in the third method embodiment.
  • the ground system 601 can obtain the observation data of navigation satellites and broadcast ephemeris in real time through the global GNSS tracking station, and then calculate the orbit correction number and clock of the navigation satellite based on the position of the ground system, observation data and broadcast ephemeris.
  • the difference correction number, and the orbit correction number and the clock correction number are sent to the LEO satellite 602, so that the LEO satellite 602 corrects the orbit and clock error of the navigation satellite calculated by itself according to the orbit correction number and the clock correction number , To obtain the corrected orbit and the corrected clock difference of the navigation satellite.
  • the LEO satellite 602 determines its orbit according to the corrected orbit, the corrected clock offset and the observation data.
  • the system may also include: a communication satellite.
  • the communication satellite is located between the ground system and the low-orbit satellite, and is used to forward data sent by the ground system to the low-orbit satellite.
  • this application also provides a low-orbit satellite orbit determination device, which will be described below with reference to the accompanying drawings.
  • FIG. 7 is a structural diagram of a low-orbit satellite orbit determination device provided by an embodiment of the application. As shown in FIG. 7, the device is applied to a low-orbit satellite, and the device may include:
  • the first acquiring unit 701 is configured to acquire the broadcast ephemeris and observation data of the navigation satellite;
  • the correction unit 702 is configured to obtain positioning information according to the broadcast ephemeris, and correct the positioning information based on the correction information of the positioning information acquired and sent by the ground system;
  • the first calculation unit 703 is configured to use the corrected positioning information and the observation data to determine the orbit of the low-orbit satellite.
  • the correction information is calculated by the ground system according to the position of the ground system, the observation data of the navigation satellite, and the broadcast ephemeris.
  • the positioning information includes the orbit and clock offset of the navigation satellite
  • the correction information includes the orbit correction number and the clock offset correction number of the navigation satellite
  • the corrected positioning information includes the corrected Orbit and corrected clock difference.
  • the orbit correction number is obtained by the ground system according to the real-time precision orbit of the navigation satellite and the orbit of the navigation satellite;
  • the real-time precise orbit of the navigation satellite is obtained by the ground system according to the position of the ground system, the observation data and the broadcast ephemeris;
  • the orbit of the navigation satellite is obtained by the ground system according to the broadcast ephemeris;
  • the clock error correction number is obtained by the ground system according to the real-time precision clock error of the navigation satellite and the clock error of the navigation satellite;
  • the real-time precision clock offset of the navigation satellite is obtained by the ground system according to the observation data and the real-time precision orbit;
  • the clock offset of the navigation satellite is obtained by the ground system according to the broadcast ephemeris.
  • the first calculation unit includes:
  • the first acquisition subunit is configured to perform filtering calculation according to the corrected orbit, the corrected clock offset, and the observation data to obtain orbit parameters of the low-orbit satellite in preset directions;
  • the first calculation subunit is used to calculate the sum of the variances of the orbit parameters of the low-orbit satellite in preset directions;
  • the first determining subunit is configured to determine the orbital parameters of the low-orbit satellite in the preset directions when the sum of the variances of the orbital parameters in the preset directions is less than the preset threshold. Describe the orbit of a low-orbiting satellite.
  • the device further includes:
  • the first judgment unit is used to judge whether the time information of the positioning information and the correction information match
  • the correction unit is specifically configured to use the correction information to correct the positioning information when the judgment result of the first judgment unit is a match.
  • the device further includes:
  • the second judgment unit is configured to judge whether the correction information is available according to the integrity information acquired and sent by the ground system; the integrity information includes a mark indicating whether the correction information is available;
  • the correction unit is specifically configured to correct the positioning information when the judgment result of the second judgment unit is that the correction information is available.
  • FIG 8 is a structural diagram of another low-orbit satellite orbit determination device.
  • the device is applied to a ground system, and the device includes:
  • the second acquiring unit 801 is used to acquire observation data and broadcast ephemeris of navigation satellites
  • the second calculation unit 802 is configured to obtain correction information of the navigation satellite according to the position of the ground system, the observation data and the broadcast ephemeris; the correction information is used for the low-orbit satellite to correct the positioning information to obtain the corrected positioning Information; the corrected positioning information and the observation data of the navigation satellite obtained by the low-orbit satellite are used for real-time orbit determination by the low-orbit satellite.
  • the correction information includes the orbit correction number and the clock error correction number of the navigation satellite; the positioning information includes the orbit and clock error of the navigation satellite, and the corrected positioning information includes the corrected position information. Orbit and corrected clock difference.
  • the second calculation unit includes:
  • the second calculation subunit is used to obtain the real-time precise orbit of the navigation satellite according to the position of the ground system, the observation data and the broadcast ephemeris;
  • the third calculation subunit is configured to obtain the orbit of the navigation satellite according to the broadcast ephemeris
  • a fourth calculation subunit configured to obtain the orbit correction number of the navigation satellite according to the real-time precision orbit and the orbit of the navigation satellite;
  • a fifth calculation subunit configured to obtain the real-time precision clock offset of the navigation satellite according to the observation data and the real-time precision orbit;
  • the sixth calculation subunit is used to obtain the clock offset of the navigation satellite according to the broadcast ephemeris;
  • the seventh calculation subunit is configured to obtain the clock error correction number of the navigation satellite according to the real-time precision clock error and the clock error of the navigation satellite.
  • the second calculation subunit includes:
  • the second determining subunit is configured to obtain the orbit of the navigation satellite according to the broadcast ephemeris to determine the initial value of the orbit of the navigation satellite;
  • the third determining subunit is configured to correct the initial value of the navigation satellite orbit according to the position of the ground system and the observation data, and determine the corrected navigation satellite orbit as the real-time precision of the navigation satellite track.
  • the positioning information is obtained by the low-orbit satellite according to the obtained broadcast ephemeris of the navigation satellite.
  • the device further includes:
  • the third obtaining unit is configured to obtain integrity information according to the correction information, and the integrity information includes a mark of whether the correction information is available.

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Abstract

一种低轨卫星定轨方法，包括：获取导航卫星的广播星历和观测数据（S401）；根据广播星历计算获得定位信息，接收地面系统发送的定位信息的修正信息，对定位信息进行修正，获得修正后的定位信息（S402）；采用修正后的定位信息以及观测数据对低轨卫星进行定轨（S403）。该方法引入了定位信息的修正信息，利用准确的修正后的定位信息对低轨卫星进行定轨，从而提高低轨卫星的定轨精度。还公开了一种低轨卫星定轨装置。

Description

一种低轨卫星定轨方法、装置及系统
本申请要求于2019年5月16日提交中国专利局、申请号为201910406386.9、申请名称为“一种低轨卫星定轨方法、装置及系统”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及卫星通信技术领域，具体涉及一种低轨卫星定轨方法、装置及系统。
背景技术
随着全球导航卫星系统(Global Navigation Satellite System，GNSS)技术的不断发展，其全球性、高精度以及低成本等特点，使得GNSS测量技术逐渐成为低轨卫星定位的主要技术手段。低轨卫星搭载GNSS接收机，以实时获取GNSS观测数据和GNSS卫星发送的广播星历，其中，GNSS观测数据包括伪距观测值和载波相位观测值。在实际定轨时，先利用广播星历确定导航卫星的位置和钟差，再根据导航卫星的位置、钟差以及观测数据确定低轨卫星的位置。然而，由于广播星历自身均存在误差，低轨卫星在利用广播星历和观测数据进行定轨时，会导致定轨精度仅能达到0.3-0.5米。伴随着各类领域的不断发展，对低轨卫星定轨的要求更高，通常达到厘米级。显然，现有的卫星定轨方法难以满足行业发展需求。
发明内容
有鉴于此，本申请实施例提供一种卫星定轨方法、装置及系统，以提升卫星定轨精度。
为解决上述问题，本申请实施例提供的技术方案如下：
本申请实施例第一方面，提供了一种低轨卫星定轨方法，所述方法应用于所述低轨卫星，所述方法包括：
获取导航卫星的广播星历和观测数据；
根据所述广播星历，获得定位信息，基于地面系统获取并发送来的所述定位信息的修正信息，对所述定位信息进行修正；
采用修正后的定位信息以及所述观测数据对所述低轨卫星进行定轨。
在一种可能的实现方式中，所述修正信息是由所述地面系统根据地面系统的位置、导航卫星的观测数据以及广播星历计算获得的。
在一种可能的实现方式中，所述定位信息包括导航卫星的轨道和钟差，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述修正后的定位信息包括修正后的轨道和修正后的钟差。
在一种可能的实现方式中，所述轨道改正数是由所述地面系统根据导航卫星的实时精密轨道和导航卫星的轨道获得的；
所述导航卫星的实时精密轨道是由所述地面系统根据地面系统的位置、所述观测数据和所述广播星历而获得的；
所述导航卫星的轨道是由所述地面系统根据所述广播星历获得的；
所述钟差改正数是由所述地面系统根据导航卫星的实时精密钟差和导航卫星的钟差获得的；
所述导航卫星的实时精密钟差是由所述地面系统根据所述观测数据和所述实时精密轨道而获得的；
所述导航卫星的钟差是由所述地面系统根据所述广播星历获得的。
在一种可能的实现方式中，所述采用所述修正后的轨道和所述修正后的钟差以及所述观测数据对所述低轨卫星进行定轨，包括：
根据所述修正后的轨道、所述修正后的钟差以及所述观测数据进行滤波计算，获得所述低轨卫星在预设各方向上的轨道参数；
计算所述低轨卫星在预设各方向上的轨道参数的方差之和；
当所述低轨卫星在预设各方向上的轨道参数的方差之和小于预设阈值时，根据所述低轨卫星在预设各方向上的轨道参数确定所述低轨卫星的轨道。
在一种可能的实现方式中，所述基于地面系统获取并发送来的所述定位信息的修正信息，对所述定位信息进行修正之前，所述方法还包括：
判断所述定位信息以及所述修正信息的时间信息是否匹配；
如果匹配，对所述定位信息进行修正。
在一种可能的实现方式中，所述在对所述定位信息进行修正之前，所述方法还包括：
根据所述地面系统获取并发送来的完好性信息，判断所述修正信息是否可用；所述完好性信息包括所述修正信息是否可用的标记；
如果是，则对所述定位信息进行修正。
本申请实施例第二方面，提供了一种低轨卫星定轨方法，所述方法应用于地面系统，所述方法包括：
获取导航卫星的观测数据和广播星历；
根据地面系统的位置、所述观测数据和广播星历，获得导航卫星的修正信息；所述修正信息用于低轨卫星对定位信息进行修正，获得修正后的定位信息；所述修正后的定位信息以及所述低轨卫星获得的所述导航卫星的观测数据用于所述低轨卫星进行实时定轨。
在一种可能的实现方式中，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述定位信息包括导航卫星的轨道和钟差，所述修正后的定位信息包括修正后的轨道和修正后的钟差。
在一种可能的实现方式中，所述根据地面系统的位置、所述观测数据和广播星历，获得导航卫星的修正信息，包括：
根据地面系统的位置、所述观测数据和所述广播星历，获得所述导航卫星的实时精密轨道；
根据所述广播星历获得所述导航卫星的轨道；
根据所述实时精密轨道和所述导航卫星的轨道，获得所述导航卫星的轨道改正数；
根据所述观测数据和所述实时精密轨道，获得所述导航卫星的实时精密钟差；
根据所述广播星历获得述导航卫星的钟差；
根据所述实时精密钟差和所述导航卫星的钟差，获得所述导航卫星的钟差改正数。
在一种可能的实现方式中，所述根据地面系统的位置、所述观测数据和所述广播星历，获得所述导航卫星的实时精密轨道，包括：
根据所述广播星历获得所述导航卫星的轨道，以确定为所述导航卫星轨道的初值；
根据所述地面系统的位置、所述观测数据对所述导航卫星轨道的初值进行修正，将修正后的所述导航卫星轨道确定为所述导航卫星的实时精密轨道。
在一种可能的实现方式中，所述定位信息是由所述低轨卫星根据获取的所述导航卫星的广播星历获得的。
在一种可能的实现方式中，所述方法还包括：
根据所述修正信息获得完好性信息，所述完好性信息包括所述修正信息是否可用的标记。
本申请实施例第三方面，提供了一种低轨卫星定轨系统，所述系统包括：地面系统、低轨卫星；
所述地面系统，用于执行第一方面所述的方法；
所述低轨卫星，用于执行第二方面所述的方法。
本申请实施例第四方面，提供了一种低轨卫星定轨装置，所述装置应用于所述低轨卫星，所述装置包括：
第一获取单元，用于获取导航卫星的广播星历和观测数据；
修正单元，用于根据所述广播星历，获得定位信息，基于地面系统获取并发送来的所述定位信息的修正信息，对所述定位信息进行修正；
第一计算单元，用于采用修正后的定位信息以及所述观测数据对所述低轨卫星进行定轨。
在一种可能的实现方式中，所述修正信息是由所述地面系统根据地面系统的位置、导航卫星的观测数据以及广播星历计算获得的。
在一种可能的实现方式中，所述定位信息包括导航卫星的轨道和钟差，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述修正后的定位信息包括修正后的轨道和修正后的钟差。
在一种可能的实现方式中，所述轨道改正数是由所述地面系统根据导航卫星的实时精密轨道和导航卫星的轨道获得的；
所述导航卫星的实时精密轨道是由所述地面系统根据地面系统的位置、所述观测数据和所述广播星历而获得的；
所述导航卫星的轨道是由所述地面系统根据所述广播星历获得的；
所述钟差改正数是由所述地面系统根据导航卫星的实时精密钟差和导航 卫星的钟差获得的；
所述导航卫星的实时精密钟差是由所述地面系统根据所述观测数据和所述实时精密轨道而获得的；
所述导航卫星的钟差是由所述地面系统根据所述广播星历获得的。
在一种可能的实现方式中，所述第一计算单元，包括：
第一获取子单元，用于根据所述修正后的轨道、所述修正后的钟差以及所述观测数据进行滤波计算，获得所述低轨卫星在预设各方向上的轨道参数；
第一计算子单元，用于计算所述低轨卫星在预设各方向上的轨道参数的方差之和；
第一确定子单元，用于当所述低轨卫星在预设各方向上的轨道参数的方差之和小于预设阈值时，根据所述低轨卫星在预设各方向上的轨道参数确定所述低轨卫星的轨道。
在一种可能的实现方式中，所述装置还包括：
第一判断单元，用于判断所述定位信息以及所述修正信息的时间信息是否匹配；
所述修正单元，具体用于当所述第一判断单元的判断结果为匹配时，则利用所述修正信息对所述定位信息进行修正。
在一种可能的实现方式中，所述装置还包括：
第二判断单元，用于根据所述地面系统获取并发送来的完好性信息，判断所述修正信息是否可用；所述完好性信息包括所述修正信息是否可用的标记；
所述修正单元，具体用于当所述第二判断单元的判断结果为所述修正信息可用时，对所述定位信息进行修正。
本申请实施例第五方面，提供了一种低轨卫星定轨装置，所述装置应用于地面系统，所述装置包括：
第二获取单元，用于获取导航卫星的观测数据和广播星历；
第二计算单元，用于根据地面系统的位置、所述观测数据和广播星历，获得导航卫星的修正信息；所述修正信息用于低轨卫星对定位信息进行修正，获得修正后的定位信息；所述修正后的定位信息以及所述低轨卫星获得的所述导航卫星的观测数据用于所述低轨卫星进行实时定轨。
在一种可能的实现方式中，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述定位信息包括导航卫星的轨道和钟差，所述修正后的定位信息包括修正后的轨道和修正后的钟差。
在一种可能的实现方式中，所述第二计算单元，包括：
第二计算子单元，用于根据地面系统的位置、所述观测数据和所述广播星历，获得所述导航卫星的实时精密轨道；
第三计算子单元，用于根据所述广播星历获得所述导航卫星的轨道；
第四计算子单元，用于根据所述实时精密轨道和所述导航卫星的轨道，获得所述导航卫星的轨道改正数；
第五计算子单元，用于根据所述观测数据和所述实时精密轨道，获得所述导航卫星的实时精密钟差；
第六计算子单元，用于根据所述广播星历获得述导航卫星的钟差；
第七计算子单元，用于根据所述实时精密钟差和所述导航卫星的钟差，获得所述导航卫星的钟差改正数。
在一种可能的实现方式中，所述第二计算子单元，包括：
第二确定子单元，用于根据所述广播星历获得所述导航卫星的轨道，以确定为所述导航卫星轨道的初值；
第三确定子单元，用于根据所述地面系统的位置、所述观测数据对所述导航卫星轨道的初值进行修正，将修正后的所述导航卫星轨道确定为所述导航卫星的实时精密轨道。
在一种可能的实现方式中，所述定位信息是由所述低轨卫星根据获取的所述导航卫星的广播星历获得的。
在一种可能的实现方式中，所述装置还包括：
第三获取单元，用于根据所述修正信息获得完好性信息，所述完好性信息包括所述修正信息是否可用的标记。
由此可见，本申请实施例具有如下有益效果：
本申请实施例低轨卫星首先获取导航卫星的广播星历和观测数据，根据广播星历计算获得导航卫星的定位信息。然后，接收地面系统发送的定位信息的修正信息，并对定位信息进行修正，获取修正后的定位信息。最后，采用修正 后的定位信息以及观测数据对低轨卫星进行定轨。可见，本申请实施例引入定位信息的修正信息，利用修正后的定位信息对低轨卫星进行定轨，提高定轨精度。
附图说明
图1为本申请实施例提供的一种低轨卫星定轨示例场景图；
图2为本申请实施例提供的一种低轨卫星定轨方法的流程图；
图3为本申请实施例提供的另一种低轨卫星定轨方法的流程图；
图4为本申请实施例提供的又一种低轨卫星定轨方法的流程图；
图5为本申请实施例提供的一种低轨卫星定轨框架图；
图6为本申请实施例提供的一种低轨卫星定轨系统结构图；
图7为本申请实施例提供的一种低轨卫星定轨装置结构图；
图8为本申请实施例提供的另一种低轨卫星定轨装置结构图。
具体实施方式
为使本申请的上述目的、特征和优点能够更加明显易懂，下面结合附图和具体实施方式对本申请实施例作进一步详细的说明。
为便于理解本申请实施例提供的技术方案，下面先对本申请技术方案的发现过程进行说明。
发明人经过研究发现，低轨卫星在利用GNSS进行定轨时，由于受实时性和自主性的条件限制，通常情况下，利用广播星历计算获得导航卫星的轨道和钟差，再根据导航卫星的轨道、钟差和GNSS观测数据确定低轨卫星的轨道。然而，由于广播星历自身存在误差较大，导致低轨卫星利用不精确的基准信息(导航卫星的轨道和钟差)进行实时定轨，影响低轨卫星的定轨精度。
基于此，本申请实施例提供了一种低轨卫星定轨方法，具体为，低轨卫星利用导航卫星发送的广播星历获得导航卫星的定位信息，并接收地面系统发送的定位信息的修正信息，以对定位信息进行修正，获得修正后的定位信息。再采用修正后的定位信息以及观测数据对低轨卫星进行定轨。即，利用准确的定位信息对低轨卫星进行定轨，从而提高低轨卫星的定轨精度。
为便于理解本申请实施例的技术方案，下面将先对本申请实施例的实际应用场景进行说明。
参见图1，该图为本申请实施例提供的一种低轨卫星定轨应用场景示例图，在本实施例中，为实现低轨卫星定轨，可以包括地面系统、低轨卫星。
其中，地面系统可以通过全球GNSS跟踪站实时获取导航卫星的观测数据以及广播星历，并根据地面系统的位置、观测数据和广播星历计算获得关于导航卫星的修正信息，并将修正信息发送给低轨卫星。低轨卫星根据修正信息对自身计算获得的导航卫星的定位信息进行修正，获得修正后的定位信息。最后，低轨卫星根据修正后的定位信息以及观测数据进行定轨。
需要说明的是，考虑到修正信息有效时间非常有限，需要频繁对修正信息进行更新。由于低轨卫星运行速度较快，星下点轨迹遍布全球，如果由地面系统直接与低轨卫星通信，则需要地面系统能够在全球多处地点与低轨卫星进行短时间持续通信，将占用大量通信资源。因此，在本实施例中一种可能的实现方式中，将通信卫星作为地面系统和低轨卫星之间的中继站，进行数据的转发。
可以理解的是，本申请实施例中低轨卫星是根据地面系统提供的修正信息对自身计算获得导航卫星的定位信息进行修正，为便于理解本申请实施例提供的技术方案，下面将先对本申请中地面系统确定修正信息的方法进行说明。
方法实施例一
参见图2，该图为本申请实施例提供的一种低轨卫星定轨方法的流程图，如图2所示，该方法应用于地面系统，该方法可以包括：
S201：获取导航卫星的观测数据和广播星历。
本实施例中，地面系统可以通过全球GNSS跟踪站实时获取GNSS观测数据和广播星历。在具体实现时，每个GNSS跟踪站可以搭载GNSS接收机，以通过GNSS接收机获得GNSS观测数据和广播星历。其中，GNSS观测数据是地面系统通过解析导航卫星所发送的卫星信号获得。
其中，观测数据可以包括载波相位观测值、伪距观测值等信息。其中，载波相位观测值是指GNSS接收机在接收导航卫星载波信号时刻的瞬时载波相位值；伪距是指导航卫星按照星载时钟发射某一结构为"伪随机噪声码"的信号，称为测距码信号(即粗码C/A码或精码P码)。该测距码信号从导航卫星发射经时 间Δt后，到达接收机天线；用上述信号传播时间Δt乘以电磁波在真空中的速度c，就是卫星至接收机的距离。由于传播时间Δt中包含有卫星时钟与接收机时钟不同步的误差、卫星星历误差、接收机测量噪声以及测距码在大气中传播的延迟误差等等，由此求得的距离值并非真正的站星几何距离，因此称之为"伪距"。
广播星历是导航卫星发送的无线电信号上载有预报一定时间内卫星根数的电文信息，可以用于计算导航卫星的轨道，即位置。
S202：根据地面系统的位置、观测数据和广播星历，获得导航卫星的修正信息。
本实施例中，当获取导航卫星的观测数据和广播星历后，由于地面系统的位置已知，则可以根据地面系统的位置、观测数据和广播星历，计算获得导航卫星的修正信息。其中，修正信息用于低轨卫星对定位信息进行修正，获得修正后的定位信息，该修正后的定位信息以及低轨卫星获得的导航卫星的观测数据用于低轨卫星进行实时定轨。其中，定位信息是由低轨卫星根据获取的导航卫星的广播星历获得的。
在实际应用中，修正信息可以包括导航卫星的轨道改正数和钟差改正数，定位信息可以包括导航卫星的轨道和钟差，则修正后的定位信息包括修正后的轨道和修正后的钟差。其中，轨道改正数用于低轨卫星对导航卫星的轨道进行修正，以获得修正后的轨道；钟差改正数用于低轨卫星对导航卫星的钟差进行修正，以获得修正后的钟差。低轨卫星利用修正后的轨道、修正后的钟差以及观测数据进行实时定轨。其中，导航卫星的轨道和导航卫星的钟差是由低轨卫星根据低轨卫星获得的导航卫星的广播星历而获得的。
需要说明的是，关于地面系统根据地面系统的位置、观测数据和广播星历，计算获得导航卫星的轨道改正数和钟差改正数的具体实现，和关于低轨卫星利用轨道改正数和钟差改正数对导航卫星的轨道、钟差进行修正，以及根据修正后的轨道、修正后的钟差以及观测数据进行定轨的具体实现将在后续实施例进行说明。
可以理解的是，为保证低轨卫星可以及时获取地面系统获得的轨道改正数和钟差改正数，可以利用低轨卫星和地面系统之间的通信卫星进行转发。即， 地面系统将轨道改正数和钟差改正数发送给通信卫星，以通过通信卫星将轨道改正数和钟差改正数发送给低轨卫星。也就是，利用通信卫星将地面系统发送的轨道改正数和钟差改正数转发给低轨卫星，保证轨道改正数和钟差改正数的实时性。
通过上述描述可知，地面系统可以根据自身位置信息、导航卫星的观测数据以及广播星历计算获得导航卫星的修正信息，以便将修正信息发送给低轨卫星，以使得低轨卫星利用修正信息对采用广播星历计算获得的导航卫星的定位信息进行修正，以获得修正后的定位信息，进而根据修正后的定位信息以及观测数据进行定轨，提高定轨精度。
方法实施例二
下面将结合附图对地面系统计算获得导航卫星的轨道改正数和钟差改正数的实现进行说明。
参见图3，该图为本申请实施例提供的一种获取轨道改正数和钟差改正数方法的流程图，如图3所示，该方法应用于地面系统，该方法可以包括：
S301：根据地面系统的位置、观测数据和广播星历，获得导航卫星的实时精密轨道。
本实施例中，地面系统在接收到GNSS观测数据和广播星历后，利用地面系统的位置、观测数据和广播星历计算获得导航卫星的实时精密轨道。
在具体实现时，首先利用广播星历计算导航卫星的轨道，并将其确定为导航卫星轨道的初值，然后利用地面系统的位置、观测数据对导航卫星轨道初值进行修正，将修正后的导航卫星轨道确定为导航卫星的实时精密轨道。
可以理解的是，由于地面系统的位置已知且准确，即GNSS接收机的位置已知且准确，而GNSS观测数据表示GNSS接收机与导航卫星的距离，因此，可以根据地面系统的位置以及观测数据计算获得比较准确的导航卫星的位置。而在利用广播星历计算导航卫星的位置时，由于广播星历自身存在误差，导致确定的导航卫星的位置存在一定误差。为消除误差，则利用通过观测数据获得的导航卫星的位置对通过广播星历获得的导航卫星的位置进行修正，从而得到准确导航卫星的位置，即实时精密轨道。
在实时应用时，可以利用最小二乘批处理方法计算获得导航卫星的实时精密轨道，具体为，(1)利用广播星历计算导航卫星的轨道，并作为轨道初值；(2)待全球GNSS跟踪站获取到的观测数据积累到一定时间长度时，采用最小二乘批处理方法对轨道初值进行迭代更新直到观测值残差之和小于预先设定的限值。其中，观测值残差可以为地面系统实际位置与估计值之间的残差。
可以理解的是，GNSS跟踪站所获取的观测数据也存在一定程度的误差，为保证对利用广播星历计算获得导航卫星的位置修正的准确性，通常情况下会利用多组观测数据对导航卫星的位置进行多次修正。具体实现为，先利用地面系统的位置实际值、第一组观测数据对利用广播星历获得导航卫星的位置进行修正，获得第一位置。然后再利用第一位置以及观测数据计算地面系统位置的估计值，根据地面系统的位置实际值与地面系统位置的估计值获得第一残差，如果第一残差满足预设阈值，则表明第一位置准确。如果第一残差不满足预设阈值，则利用地面系统的位置实际值、第二组观测数据对第一位置进行修正，获得第二位置。然后利用第二位置以及观测数据计算地面系统位置的估计值，根据地面系统的位置实际值与地面系统位置的估计值获得第二残差，如果第一残差与第二残差的均方根满足预设阈值，则表明第二位置准确。如果第一残差与第二残差的均方根不满足预设阈值，则利用地面系统的位置实际值、第三组观测数据对第二位置进行修正，获得第三位置。然后利用第三位置以及观测数据计算地面系统位置的估计值，根据地面系统的位置实际值与地面系统位置的估计值获得第三残差，如果第二残差与第三残差的均方根满足预设阈值，则表明第三位置准确。如果第二残差与第三残差的均方根不满足预设阈值，则继续利用其它组观测数据进行迭代更新，直至相邻两个残差的均方根满足预设阈值。
S302：根据广播星历获得导航卫星的轨道。
S303：根据实时精密轨道和导航卫星的轨道，获得导航卫星的轨道改正数。
本实施例中，当获得实时精密轨道和导航卫星的轨道后，可以根据实时精密轨道和导航卫星的轨道获得关于导航卫星的轨道改正数。
S304：根据观测数据和实时精密轨道，获得导航卫星的实时精密钟差。
S305：根据广播星历获得导航卫星的钟差。
S306：根据实时精密钟差和导航卫星的钟差，获得导航卫星的钟差改正数。
本实施例中，地面系统在计算获得导航卫星的实时精密轨道后，根据实时精密轨道和观测数据，计算获得导航卫星的实时精密钟差，以及利用广播星历计算获得导航卫星的钟差。在具体实现时，在利用观测数据获得导航卫星的实时精密钟差时，可以以实时精密轨道为约束条件，来计算获得导航卫星的实时精密钟差。然后，根据实时精密钟差和导航卫星的钟差获得导航卫星的钟差改正数。
在本申请实施例一种可能的实现方式中，地面系统在计算获得修正信息同时，还可以根据修正信息获取完好性信息，该完好性信息可以包括修正信息是否可用的标记，以便低轨卫星在接收到地面系统发送的完好性信息后，可以根据完好性信息中所包括的标记判断当前所接收的修正信息是否可以用于修正定位信息。在具体实现时，可以由地面系统中的完好性监测系统对修正信息进行判断，然后根据判断结果给出该修正信息可用或不可用的标记，再由地面系统通过完好性信息将修正信息可用或不可用的标记发送给低轨卫星。
可以理解的是，为保证低轨卫星可以及时获取地面系统发送的完好性信息，地面系统通过通信卫星向低轨卫星发送完好性信息，以使得低轨卫星根据完好性信息确定是否利用轨道改正数和钟差改正数进行修正，从而保证低轨卫星所获取的完好性信息的实时性。
在具体实现时，地面系统可以先将轨道改正数和钟差改正数发送到卫星上注站，再由卫星上注站将轨道改正数、钟差改正数以及完好性信息上传到通信卫星，当通信卫星接收到轨道改正数和钟差改正数后发送给低轨卫星。
通过上述描述可知，地面系统可以为低轨卫星提供轨道改正数和钟差改正数，在低轨卫星根据导航卫星发送的参数进行定轨时，可以先利用轨道改正数和钟差改正数对采用广播星历计算获得的导航卫星的轨道和钟差进行修正，以便利用比较准确的导航卫星的轨道和钟差进行自身定轨，以提高定轨精度。
方法实施例三
上述实施例介绍了修正信息的获取，下面将结合附图对本申请实施例提供的低轨卫星利用修正信息进行定轨的方法进行说明。
参见图4，该图为本申请实施例提供的一种低轨卫星定轨方法的流程图，如图4所示，该方法应用于低轨卫星，该方法可以包括：
S401：获取导航卫星的广播星历和观测数据。
S402：根据广播星历，获得定位信息，基于地面系统获取并发送来的定位信息的修正信息，对定位信息进行修正。
本实施例中，低轨卫星可以接收导航卫星发送的广播星历，根据该广播星历获得定位信息，并接收地面系统发送的定位信息的修正信息，以利用修正信息对定位信息进行修正，获得修正后的定位信息。其中，修正信息是由地面系统根据地面系统的位置、导航卫星的观测数据以及广播星历计算获得的，关于修正信息的获取可以参见方法实施例一。
在具体实现时，定位信息可以包括导航卫星的轨道和钟差，修正信息包括导航卫星的轨道改正数和钟差改正数；修正后的定位信息可以包括修正后的轨道和修正后的钟差。其中，关于轨道改正数和钟差改正数的获取可以参见方法实施例二。
在实际应用中，低轨卫星可以安装GNNS接收机，以便利用GNSS接收机实时获取导航卫星的广播星历和GNSS观测数据。其中，GNSS观测数据是低轨卫星通过解析导航卫星所发送的卫星信号获得。
S403：采用修正后的定位信息以及观测数据对低轨卫星进行定轨。
本实施例中，当通过S402获取修正后的定位信息后，采用修正后的定位信息以及观测数据对低轨卫星进行定轨。
在具体实现时，由于定位信息可以包括导航卫星的轨道和钟差，修正信息可以包括导航卫星的轨道改正数和钟差改正数，则可以采用修正后的轨道和修正后的钟差以及观测数据对低轨卫星进行定轨。其中，关于利用修正后的轨道和修正后的钟差以及观测数据对低轨卫星进行定轨的具体实现将在后续实施例进行说明。
通过上述描述可知，低轨卫星在获取导航卫星的广播星历和观测数据，根据广播星历计算获得导航卫星的定位信息的同时，接收地面系统发送的定位信息的修正信息，并对定位信息进行修正，获取修正后的定位信息。再采用修正后的定位信息以及观测数据对低轨卫星进行定轨。可见，本申请实施例引入地 面系统获取的定位信息的修正信息，利用修正后的定位信息对低轨卫星进行定轨，提高定轨精度。
在本申请实施例一种可能的实现方式中，轨道改正数是由地面系统根据导航卫星的实时精密轨道和导航卫星的轨道获得的；导航卫星的实时精密轨道是由地面系统根据地面系统的位置、观测数据和广播星历而获得的；导航卫星的轨道是由地面系统根据广播星历获得的；钟差改正数是由地面系统根据导航卫星的实时精密钟差和导航卫星的钟差获得的；导航卫星的实时精密钟差是由地面系统根据观测数据和实时精密轨道而获得的；导航卫星的钟差是由地面系统根据广播星历获得的。
其中，关于地面系统计算获得轨道改正数和钟差改正数的具体实现，可以参见方法实施例二。
在实际应用中，低轨卫星可以安装通信卫星接收机，以便利用该通信卫星接收机接收通信卫星转发的轨道改正数和钟差改正数。在具体实现时，低轨卫星可以安装同时具备接收导航卫星信号、通信卫星信号功能的一体化接收设备，也可以安装多个接收不同信号的独立设备。
在具体实现时，当低轨卫星获取导航卫星的轨道和钟差以及轨道改正数和钟差改正数，可以通过以下公式计算获得导航卫星的修正后的轨道和修正后的钟差：
[R T N] precise＝[R T N] brdc±[dR dT dN] SSR-orbit    (1)
dt precise＝dt brdc±dt SSR-clock     (2)
其中，R/T/N分别为卫星轨道在径向(Radial)/切向(Tangential)/法向(Normal)的分量，[R T N] precise为恢复的高精度实时轨道，[R T N] brdc为广播星历计算出来的导航卫星的轨道，[dR dT dN] SSR-orbit为轨道在R/T/N三个方向的改正数。dt precise为恢复的高精度实时钟差，dt brdc为广播星历计算的导航卫星的钟差，dt SSR-clock为钟差改正数。需要说明的是，R/T/N三个方向也可以换成X/Y/Z方向，只需要乘以相应的旋转矩阵即可，等式右边采用“+”还是“-”号，与改正数计算方法有关。
可以理解的是，当低轨卫星在实时定轨时，当获取到采用广播星历计算的导航卫星的轨道和钟差以及从地面系统发送的轨道改正数和钟差改正数后，利 用公式(1)和公式(2)可以计算获得导航卫星的修正后的轨道和修正后的钟差，再利用修正后的轨道和修正后的钟差以及观测数据进行定轨。
通过上述描述可知，低轨卫星在接收导航卫星发送的广播星历以及获取观测数据，根据广播星历计算获得导航卫星的轨道以及钟差的同时，接收地面系统获得并发送的导航卫星的轨道改正数和钟差改正数。再分别利用轨道改正数对根据广播星历计算获得导航卫星的轨道进行修正，利用钟差改正数对根据广播星历计算获得导航卫星的钟差进行修正，从而获得导航卫星的修正后的轨道和修正后的钟差。再根据导航卫星的修正后的轨道、修正后的钟差以及观测数据确定低轨卫星的轨道和速度。可见，本申请实施例引入轨道改正数和钟差改正数，从而提高导航卫星轨道和钟差的整体精度，进而在根据导航卫星的轨道和钟差对低轨卫星的轨道进行定位时，提高定轨精度。
在本申请实施例一种可能的实现方式中，为保证利用修正后的轨道、修正后的钟差以及观测数据进行低轨卫星定轨的精度，每一步滤波结束后，结合轨道参数的方差之和判断滤波是否收敛，若滤波方程收敛，表明当前获得低轨卫星的定轨结果可靠。具体为，根据修正后的轨道、修正后的钟差以及观测数据进行滤波计算，获得低轨卫星在预设各方向上的轨道参数；计算所述低轨卫星在预设各方向上轨道参数的方差之和；当所述低轨卫星在预设各方向上的轨道参数的方差之和小于预设阈值时，根据所述低轨卫星在预设各方向上的轨道参数确定低轨卫星的轨道。
在具体实现时，将修正后的轨道、修正后的钟差以及观测数据输入滤波方程，当滤波方程输出的低轨卫星在预设各方向上的轨道参数的方差之和小于预设阈值时，根据滤波方程输出的低轨卫星在预设各方向上的轨道参数确定低轨卫星的位置。其中，滤波方程可以为卡尔曼滤波方程。
在实际应用时，可以针对滤波方程预先设置状态参数的初始值以及协方差矩阵的初始值，该协方差矩阵用于表示低轨卫星在三个方向的位置误差，然后利用修正后的轨道、修正后的钟差、观测数据、对初始状态参数以及协方差矩阵进行更新，当更新后的协方差矩阵中低轨卫星在三个方向的位置方差之和小于预设阈值时，则表示滤波收敛，则将此时输出的低轨卫星的轨道参数确定为低轨卫星的位置。
在具体实现时，利用当前时刻获得的星载GNSS观测值、修正后的轨道，修正后的钟差，对滤波方程进行状态更新，得到更新后的协方差信息，如果位置参数的方差之和小于预先设定的限值，则认为滤波收敛；否则认为滤波不收敛，利用本次滤波计算得到的位置和速度参数，采用动力学模型预测下一时刻的低轨卫星位置和速度信息，作为下一时刻滤波参数的先验值。在实际应用中，滤波算法可以为基于UD分解的扩展卡尔曼滤波，利用星载GNSS观测值，导航卫星的修正后的轨道和修正后的钟差作为输入，持续滤波，直至卡尔曼滤波收敛。
在本申请实施例一种可能的实现方式中，由于导航卫星轨道在不断变化，为保证地面系统在获取修正信息所依据的导航卫星的广播星历以及观测数据的时间信息与低轨卫星在获取定位信息所依据的导航卫星的广播星历以及观测数据的时间信息匹配，进而保证低轨卫星可以根据地面系统所发送的修正信息对匹配的定位信息进行修正，在修正之前，低轨卫星可以判断定位信息的时间信息和修正信息的时间信息是否匹配，如匹配，则利用修正信息对定位信息进行修正。
在具体实现时，地面系统在计算获得修正信息时，可以在该修正信息中添加时间戳，该时间戳所对应的时刻为可以使用该修正信息进行修正的定位信息的时刻；低轨卫星在获取定位信息同时，添加时间戳，该时间戳所对应的时刻为获取定位信息所指定的时刻。当低轨卫星接收到地面系统发送的修正信息后，可以根据修正信息中的时间戳以及定位信息的时间戳判断二者是否匹配，如果匹配，则对定位信息进行修正。其中，二者匹配可以为二者时间戳相等，或者二者的时间差在预设时间范围内。
在具体实现时，可以利用广播星历中提供的每颗卫星的IODE值与每个轨道改正数和钟差改正数附加的IODE值进行数值匹配，如果数值相等，则利用轨道改正数对广播星历计算出来的轨道进行改正，利用钟差改正数对广播星历计算出来的钟差进行改正。
在本申请实施例一种可能的实现方式中，地面系统在利用修正信息对定位信息进行修正之前，还可以判断所接收的修正信息是否可用，以避免利用不可用的修正信息对定位信息进行修正，影响定轨的准确性。具体为，低轨卫星根 据地面系统获取并发送来的完好性信息，判断修正信息是否可用；该完好性信息包括修正信息是否可用的标记。如果修正信息可用，则对定位信息进行修正。即，如果完好性信息中包括修正信息可用的标记，则利用修正信息对定位信息进行修正；如果完好性信息中包括修正信息不可用的标记，则不对定位信息进行修正。
为便于理解本申请的实施原理，参见图5，该图为本申请实施例提供的一种低轨卫星定轨框架图，低轨卫星搭载GNSS接收机获取星载GNSS观测数据、导航卫星发送的广播星历以及地面系统发送的轨道改正数和钟差改正数。然后，计算获得导航卫星的修正后的轨道，即实际轨道和修正后的钟差，即实际钟差。再根据导航卫星的实际轨道、实际钟差以及GNSS观测数据计算获得低轨卫星的轨道和速度。对计算获得低轨卫星的轨道和速度进行卡尔曼滤波，如果滤波收敛，表明定轨结果可靠，则输出结果。如果不收敛，则不输出结果。每次滤波结束后，利用本次滤波计算得到的位置和速度参数，采用动力学模型预测下一时刻的低轨卫星位置和速度信息，作为下一时刻滤波参数的先验值，再次进行滤波，依次循环。
设备实施例
基于上述方法实施例，本申请还提供了一种低轨卫星定轨系统，下面将结合附图对该系统进行说明。
参见图6，该图为本申请实施例提供的一种低轨卫星定轨系统结构图，如图6所示，该系统可以包括：
可以包括地面系统601，低轨卫星602。
地面系统601，用于执行方法实施例一和方法实施例二所述的方法；
低轨卫星602，用于执行方法实施例三所述的方法。
在具体实现时，地面系统601可以通过全球GNSS跟踪站实时获取导航卫星的观测数据以及广播星历，然后根据地面系统的位置、观测数据和广播星历计算获得关于导航卫星的轨道改正数和钟差改正数，并将轨道改正数和钟差改正数发送给低轨卫星602，以使得低轨卫星602根据轨道改正数和钟差改正数对自身计算获得的导航卫星的轨道和钟差进行修正，获 得导航卫星的修正后的轨道和修正后的钟差。低轨卫星602再根据修正后的轨道、修正后的钟差和观测数据进行定轨。
在一种可能的实现方式中，系统还可以包括：通信卫星。该通信卫星位于地面系统和低轨卫星之间，用于将地面系统发送的数据转发给低轨卫星。
需要说明的是，本实施例中，地面系统和低轨卫星的具体实现可以参见上述方法实施例，本实施例在此不再赘述。
装置实施例一
基于上述方法实施例，本申请还提供了一种低轨卫星定轨装置，下面将结合附图对该装置进行说明。
参见图7，该图为本申请实施例提供的一种低轨卫星定轨装置结构图，如图7所示，该装置应用于低轨卫星，该装置可以包括：
第一获取单元701，用于获取导航卫星的广播星历和观测数据；
修正单元702，用于根据所述广播星历，获得定位信息，基于地面系统获取并发送来的所述定位信息的修正信息，对所述定位信息进行修正；
第一计算单元703，用于采用修正后的定位信息以及所述观测数据对所述低轨卫星进行定轨。
在一种可能的实现方式中，所述修正信息是由所述地面系统根据地面系统的位置、导航卫星的观测数据以及广播星历计算获得的。
在一种可能的实现方式中，所述定位信息包括导航卫星的轨道和钟差，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述修正后的定位信息包括修正后的轨道和修正后的钟差。
在一种可能的实现方式中，所述轨道改正数是由所述地面系统根据导航卫星的实时精密轨道和导航卫星的轨道获得的；
所述导航卫星的实时精密轨道是由所述地面系统根据地面系统的位置、所述观测数据和所述广播星历而获得的；
所述导航卫星的轨道是由所述地面系统根据所述广播星历获得的；
所述钟差改正数是由所述地面系统根据导航卫星的实时精密钟差和导航卫星的钟差获得的；
所述导航卫星的实时精密钟差是由所述地面系统根据所述观测数据和所述实时精密轨道而获得的；
所述导航卫星的钟差是由所述地面系统根据所述广播星历获得的。
在一种可能的实现方式中，所述第一计算单元，包括：
第一获取子单元，用于根据所述修正后的轨道、所述修正后的钟差以及所述观测数据进行滤波计算，获得所述低轨卫星在预设各方向上的轨道参数；
第一计算子单元，用于计算所述低轨卫星在预设各方向上的轨道参数的方差之和；
第一确定子单元，用于当所述低轨卫星在预设各方向上的轨道参数的方差之和小于预设阈值时，根据所述低轨卫星在预设各方向上的轨道参数确定所述低轨卫星的轨道。
在一种可能的实现方式中，所述装置还包括：
第一判断单元，用于判断所述定位信息以及所述修正信息的时间信息是否匹配；
所述修正单元，具体用于当所述第一判断单元的判断结果为匹配时，则利用所述修正信息对所述定位信息进行修正。
在一种可能的实现方式中，所述装置还包括：
第二判断单元，用于根据所述地面系统获取并发送来的完好性信息，判断所述修正信息是否可用；所述完好性信息包括所述修正信息是否可用的标记；
所述修正单元，具体用于当所述第二判断单元的判断结果为所述修正信息可用时，对所述定位信息进行修正。
需要说明的是，本实施例中各个单元的实现可以参见上述方法实例，本实施例在此不再赘述。
装置实施例二
参见图8，该图为另一种低轨卫星定轨装置结构图，所述装置应用于地面系统，所述装置包括：
第二获取单元801，用于获取导航卫星的观测数据和广播星历；
第二计算单元802，用于根据地面系统的位置、所述观测数据和广播星历，获得导航卫星的修正信息；所述修正信息用于低轨卫星对定位信息进行修正，获得修正后的定位信息；所述修正后的定位信息以及所述低轨卫星获得的所述导航卫星的观测数据用于所述低轨卫星进行实时定轨。
在一种可能的实现方式中，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述定位信息包括导航卫星的轨道和钟差，所述修正后的定位信息包括修正后的轨道和修正后的钟差。
在一种可能的实现方式中，所述第二计算单元，包括：
第二计算子单元，用于根据地面系统的位置、所述观测数据和所述广播星历，获得所述导航卫星的实时精密轨道；
第三计算子单元，用于根据所述广播星历获得所述导航卫星的轨道；
第四计算子单元，用于根据所述实时精密轨道和所述导航卫星的轨道，获得所述导航卫星的轨道改正数；
第五计算子单元，用于根据所述观测数据和所述实时精密轨道，获得所述导航卫星的实时精密钟差；
第六计算子单元，用于根据所述广播星历获得述导航卫星的钟差；
第七计算子单元，用于根据所述实时精密钟差和所述导航卫星的钟差，获得所述导航卫星的钟差改正数。
在一种可能的实现方式中，所述第二计算子单元，包括：
第二确定子单元，用于根据所述广播星历获得所述导航卫星的轨道，以确定为所述导航卫星轨道的初值；
第三确定子单元，用于根据所述地面系统的位置、所述观测数据对所述导航卫星轨道的初值进行修正，将修正后的所述导航卫星轨道确定为所述导航卫星的实时精密轨道。
在一种可能的实现方式中，所述定位信息是由所述低轨卫星根据获取的所述导航卫星的广播星历获得的。在一种可能的实现方式中，所述装置还包括：
第三获取单元，用于根据所述修正信息获得完好性信息，所述完好性信息包括所述修正信息是否可用的标记。
需要说明的是，本实施例中各个单元的实现可以参见上述方法实施例，本实施例在此不再赘述。
以上详细描述了本发明的优选实施方式，但是本申请并不限于上述实施方式中的具体细节，在本发明的技术构思范围内，可以对本发明的技术方案进行多种等同变换(如数量、形状、位置等)，这些等同变换均属于本发明的保护范围。

Claims (27)

  1. 一种低轨卫星定轨方法，其特征在于，所述方法应用于所述低轨卫星，所述方法包括：
    获取导航卫星的广播星历和观测数据；
    根据所述广播星历，获得定位信息，基于地面系统获取并发送来的所述定位信息的修正信息，对所述定位信息进行修正；
    采用修正后的定位信息以及所述观测数据对所述低轨卫星进行定轨。
  2. 根据权利要求1所述的方法，其特征在于，所述修正信息是由所述地面系统根据地面系统的位置、导航卫星的观测数据以及广播星历计算获得的。
  3. 根据权利要求1所述的方法，其特征在于，所述定位信息包括导航卫星的轨道和钟差，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述修正后的定位信息包括修正后的轨道和修正后的钟差。
  4. 根据权利要求3所述的方法，其特征在于，所述轨道改正数是由所述地面系统根据导航卫星的实时精密轨道和导航卫星的轨道获得的；
    所述导航卫星的实时精密轨道是由所述地面系统根据地面系统的位置、所述观测数据和所述广播星历而获得的；
    所述导航卫星的轨道是由所述地面系统根据所述广播星历获得的；
    所述钟差改正数是由所述地面系统根据导航卫星的实时精密钟差和导航卫星的钟差获得的；
    所述导航卫星的实时精密钟差是由所述地面系统根据所述观测数据和所述实时精密轨道而获得的；
    所述导航卫星的钟差是由所述地面系统根据所述广播星历获得的。
  5. 根据权利要求3所述的方法，其特征在于，所述采用所述修正后的轨道和所述修正后的钟差以及所述观测数据对所述低轨卫星进行定轨，包括：
    根据所述修正后的轨道、所述修正后的钟差以及所述观测数据进行滤波计算，获得所述低轨卫星在预设各方向上的轨道参数；
    计算所述低轨卫星在预设各方向上的轨道参数的方差之和；
    当所述低轨卫星在预设各方向上的轨道参数的方差之和小于预设阈值时，根据所述低轨卫星在预设各方向上的轨道参数确定所述低轨卫星的轨道。
  6. 根据权利要求1所述的方法，其特征在于，所述基于地面系统获取并发送来的所述定位信息的修正信息，对所述定位信息进行修正之前，所述方法还包括：
    判断所述定位信息以及所述修正信息的时间信息是否匹配；
    如果匹配，对所述定位信息进行修正。
  7. 根据权利要求1-6任一项所述的方法，其特征在于，所述在对所述定位信息进行修正之前，所述方法还包括：
    根据所述地面系统获取并发送来的完好性信息，判断所述修正信息是否可用；所述完好性信息包括所述修正信息是否可用的标记；
    如果是，则对所述定位信息进行修正。
  8. 一种低轨卫星定轨方法，其特征在于，所述方法应用于地面系统，所述方法包括：
    获取导航卫星的观测数据和广播星历；
    根据地面系统的位置、所述观测数据和广播星历，获得导航卫星的修正信息；所述修正信息用于低轨卫星对定位信息进行修正，获得修正后的定位信息；所述修正后的定位信息以及所述低轨卫星获得的所述导航卫星的观测数据用于所述低轨卫星进行实时定轨。
  9. 根据权利要求8所述的方法，其特征在于，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述定位信息包括导航卫星的轨道和钟差，所述修正后的定位信息包括修正后的轨道和修正后的钟差。
  10. 根据权利要求8所述的方法，其特征在于，所述根据地面系统的位置、所述观测数据和广播星历，获得导航卫星的修正信息，包括：
    根据地面系统的位置、所述观测数据和所述广播星历，获得所述导航卫星的实时精密轨道；
    根据所述广播星历获得所述导航卫星的轨道；
    根据所述实时精密轨道和所述导航卫星的轨道，获得所述导航卫星的轨道改正数；
    根据所述观测数据和所述实时精密轨道，获得所述导航卫星的实时精密钟差；
    根据所述广播星历获得述导航卫星的钟差；
    根据所述实时精密钟差和所述导航卫星的钟差，获得所述导航卫星的钟差改正数。
  11. 根据权利要求10所述的方法，其特征在于，所述根据地面系统的位置、所述观测数据和所述广播星历，获得所述导航卫星的实时精密轨道，包括：
    根据所述广播星历获得所述导航卫星的轨道，以确定为所述导航卫星轨道的初值；
    根据所述地面系统的位置、所述观测数据对所述导航卫星轨道的初值进行修正，将修正后的所述导航卫星轨道确定为所述导航卫星的实时精密轨道。
  12. 根据权利要求8所述的方法，其特征在于，所述定位信息是由所述低轨卫星根据获取的所述导航卫星的广播星历获得的。
  13. 根据权利要求8-12任一项所述的方法，其特征在于，所述方法还包括：
    根据所述修正信息获得完好性信息，所述完好性信息包括所述修正信息是否可用的标记。
  14. 一种低轨卫星定轨系统，其特征在于，所述系统包括：地面系统、低轨卫星；
    所述地面系统，用于执行权利要求8-13任一项所述方法；
    所述低轨卫星，用于执行权利要求1-7任一项所述方法。
  15. 一种低轨卫星定轨装置，其特征在于，所述装置应用于所述低轨卫星，所述装置包括：
    第一获取单元，用于获取导航卫星的广播星历和观测数据；
    修正单元，用于根据所述广播星历，获得定位信息，基于地面系统获取并发送来的所述定位信息的修正信息，对所述定位信息进行修正；
    第一计算单元，用于采用修正后的定位信息以及所述观测数据对所述低轨卫星进行定轨。
  16. 根据权利要求15所述的装置，其特征在于，所述修正信息是由所述地面系统根据地面系统的位置、导航卫星的观测数据以及广播星历计算获得的。
  17. 根据权利要求16所述的装置，其特征在于，所述定位信息包括导航卫星的轨道和钟差，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述修正后的定位信息包括修正后的轨道和修正后的钟差。
  18. 根据权利要求17所述的装置，其特征在于，所述轨道改正数是由所述地面系统根据导航卫星的实时精密轨道和导航卫星的轨道获得的；
    所述导航卫星的实时精密轨道是由所述地面系统根据地面系统的位置、所述观测数据和所述广播星历而获得的；
    所述导航卫星的轨道是由所述地面系统根据所述广播星历获得的；
    所述钟差改正数是由所述地面系统根据导航卫星的实时精密钟差和导航卫星的钟差获得的；
    所述导航卫星的实时精密钟差是由所述地面系统根据所述观测数据和所述实时精密轨道而获得的；
    所述导航卫星的钟差是由所述地面系统根据所述广播星历获得的。
  19. 根据权利要求17所述的装置，其特征在于，所述第一计算单元，包括：
    第一获取子单元，用于根据所述修正后的轨道、所述修正后的钟差以及所述观测数据进行滤波计算，获得所述低轨卫星在预设各方向上的轨道参数；
    第一计算子单元，用于计算所述低轨卫星在预设各方向上的轨道参数的方差之和；
    第一确定子单元，用于当所述低轨卫星在预设各方向上的轨道参数的方差之和小于预设阈值时，根据所述低轨卫星在预设各方向上的轨道参数确定所述低轨卫星的轨道。
  20. 根据权利要求15所述的装置，其特征在于，所述装置还包括：
    第一判断单元，用于判断所述定位信息以及所述修正信息的时间信息是否匹配；
    所述修正单元，具体用于当所述第一判断单元的判断结果为匹配时，则利用所述修正信息对所述定位信息进行修正。
  21. 根据权利要求15-20任一项所述的装置，其特征在于，所述装置还包括：
    第二判断单元，用于根据所述地面系统获取并发送来的完好性信息，判断所述修正信息是否可用；所述完好性信息包括所述修正信息是否可用的标记；
    所述修正单元，具体用于当所述第二判断单元的判断结果为所述修正信息可用时，对所述定位信息进行修正。
  22. 一种低轨卫星定轨装置，其特征在于，所述装置应用于地面系统，所述装置包括：
    第二获取单元，用于获取导航卫星的观测数据和广播星历；
    第二计算单元，用于根据地面系统的位置、所述观测数据和广播星历，获得导航卫星的修正信息；所述修正信息用于低轨卫星对定位信息进行修正，获得修正后的定位信息；所述修正后的定位信息以及所述低轨卫星获得的所述导航卫星的观测数据用于所述低轨卫星进行实时定轨。
  23. 根据权利要求22所述的装置，其特征在于，所述修正信息包括导航卫星的轨道改正数和钟差改正数；所述定位信息包括导航卫星的轨道和钟差，所述修正后的定位信息包括修正后的轨道和修正后的钟差。
  24. 根据权利要求23所述的装置，其特征在于，所述第二计算单元，包括：
    第二计算子单元，用于根据地面系统的位置、所述观测数据和所述广播星历，获得所述导航卫星的实时精密轨道；
    第三计算子单元，用于根据所述广播星历获得所述导航卫星的轨道；
    第四计算子单元，用于根据所述实时精密轨道和所述导航卫星的轨道，获得所述导航卫星的轨道改正数；
    第五计算子单元，用于根据所述观测数据和所述实时精密轨道，获得所述导航卫星的实时精密钟差；
    第六计算子单元，用于根据所述广播星历获得述导航卫星的钟差；
    第七计算子单元，用于根据所述实时精密钟差和所述导航卫星的钟差，获得所述导航卫星的钟差改正数。
  25. 根据权利要求24所述的装置，其特征在于，所述第二计算子单元，包括：
    第二确定子单元，用于根据所述广播星历获得所述导航卫星的轨道，以确 定为所述导航卫星轨道的初值；
    第三确定子单元，用于根据所述地面系统的位置、所述观测数据对所述导航卫星轨道的初值进行修正，将修正后的所述导航卫星轨道确定为所述导航卫星的实时精密轨道。
  26. 根据权利要求22所述的装置，其特征在于，所述定位信息是由所述低轨卫星根据获取的所述导航卫星的广播星历获得的。
  27. 根据权利要求22-26任一项所述的装置，其特征在于，所述装置还包括：
    第三获取单元，用于根据所述修正信息获得完好性信息，所述完好性信息包括所述修正信息是否可用的标记。
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CN112526553A (zh) * 2020-12-16 2021-03-19 中电科航空电子有限公司 一种基于机载位置追踪设备的定位方法及相关装置
CN114791614A (zh) * 2021-01-25 2022-07-26 华为技术有限公司 钟差预报方法和装置
EP4370944A1 (en) * 2021-07-15 2024-05-22 Qualcomm Incorporated Low-earth orbit (leo) satellite position, velocity, and time (pvt) determination for leo-based positioning
CN114509790A (zh) * 2022-02-17 2022-05-17 北京国电高科科技有限公司 一种基于低轨卫星星座的定位方法及定位系统
CN116552812B (zh) * 2023-04-12 2024-01-23 四川大学 一种电推进geo卫星自学习定轨方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090091493A1 (en) * 2004-11-04 2009-04-09 Electronics And Telecommunications Research Instit Method for correcting ionosphere error, and system and method for determining precision orbit using the same
US20130332072A1 (en) * 2008-01-10 2013-12-12 Trimble Navigation Limited Refining a position estimate of a low earth orbiting satellite
CN103675861A (zh) * 2013-11-18 2014-03-26 航天恒星科技有限公司 一种基于星载gnss多天线的卫星自主定轨方法
US20160041267A1 (en) * 2014-08-06 2016-02-11 Raytheon Company Orbital Determination (OD) Of Geosynchronous Satellites
CN106338753A (zh) * 2016-09-22 2017-01-18 北京航空航天大学 一种基于地面站/星间链路/gnss联合测量的地球同步轨道星座定轨方法
CN110058287A (zh) * 2019-05-16 2019-07-26 北京合众思壮科技股份有限公司 一种低轨卫星定轨方法、装置及系统

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1959430A (zh) * 2006-11-24 2007-05-09 中国科学院上海技术物理研究所 一种中低轨卫星的精密定轨系统及其实现方法
CN100437144C (zh) * 2007-08-13 2008-11-26 北京航空航天大学 一种卫星导航增强系统的定位方法
WO2014046917A1 (en) * 2012-09-20 2014-03-27 California Institute Of Technology Enhanced broadcast ephemeris for high accuracy assisted gps positioning
CN105301609B (zh) * 2014-06-16 2018-10-23 中国电信股份有限公司 星历修正方法和装置
CN104614734B (zh) * 2014-12-22 2017-03-29 中国科学院国家授时中心 北斗天基高精度差分电文生成方法
CN104765047B (zh) * 2015-04-20 2017-05-24 中国电子科技集团公司第五十四研究所 同步卫星运动导致站间时间同步误差的修正方法
CN109387859B (zh) * 2017-08-14 2023-05-30 千寻位置网络有限公司 基于地面跟踪站产生长期卫星轨道和钟差的方法和装置
CN108761508A (zh) * 2018-03-09 2018-11-06 羲和时空（武汉）网络科技有限公司 一种卫星位置与卫星钟差恢复及轨道钟差改正数表示方法
CN108761504A (zh) * 2018-04-04 2018-11-06 南京航空航天大学 低轨导航增强卫星系统
CN109061677B (zh) * 2018-06-28 2020-08-25 上海卫星工程研究所 利用低轨卫星进行星基导航增强的方法
CN109520512A (zh) * 2018-12-28 2019-03-26 上海海积信息科技股份有限公司 一种卫星精密定轨方法及装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090091493A1 (en) * 2004-11-04 2009-04-09 Electronics And Telecommunications Research Instit Method for correcting ionosphere error, and system and method for determining precision orbit using the same
US20130332072A1 (en) * 2008-01-10 2013-12-12 Trimble Navigation Limited Refining a position estimate of a low earth orbiting satellite
CN103675861A (zh) * 2013-11-18 2014-03-26 航天恒星科技有限公司 一种基于星载gnss多天线的卫星自主定轨方法
US20160041267A1 (en) * 2014-08-06 2016-02-11 Raytheon Company Orbital Determination (OD) Of Geosynchronous Satellites
CN106338753A (zh) * 2016-09-22 2017-01-18 北京航空航天大学 一种基于地面站/星间链路/gnss联合测量的地球同步轨道星座定轨方法
CN110058287A (zh) * 2019-05-16 2019-07-26 北京合众思壮科技股份有限公司 一种低轨卫星定轨方法、装置及系统

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112946693B (zh) * 2021-02-03 2024-01-23 中国人民解放军61540部队 一种卫星导航系统的系统时间偏差的确定方法及系统
CN112987051B (zh) * 2021-02-26 2023-01-10 北京眸星科技有限公司 一种提高卫星导航定位性能的方法
CN112987051A (zh) * 2021-02-26 2021-06-18 刘成 一种提高卫星导航定位性能的方法
CN114325786A (zh) * 2021-12-22 2022-04-12 广州南方卫星导航仪器有限公司 一种bds3-ppp定位方法及系统
CN115098828B (zh) * 2022-08-26 2022-11-04 北京控制工程研究所 近圆中低轨卫星轨道的计算方法和装置
CN115098828A (zh) * 2022-08-26 2022-09-23 北京控制工程研究所 近圆中低轨卫星轨道的计算方法和装置
CN116224746A (zh) * 2023-01-29 2023-06-06 北京航空航天大学 一种星地原子钟融合的高稳定时间基准建立方法
CN117031502B (zh) * 2023-07-03 2024-04-30 哈尔滨工程大学 实时ppp-rtk卫星钟轨改正产品完好性监测方法
CN117031502A (zh) * 2023-07-03 2023-11-10 哈尔滨工程大学 实时ppp-rtk卫星钟轨改正产品完好性监测方法
CN116840879A (zh) * 2023-09-04 2023-10-03 中国科学院国家授时中心 顾及轨道约束的低轨卫星钟差的确定方法及系统
CN116840879B (zh) * 2023-09-04 2023-12-08 中国科学院国家授时中心 顾及轨道约束的低轨卫星钟差的确定方法及系统
CN116893438A (zh) * 2023-09-11 2023-10-17 中国科学院国家授时中心 顾及钟差模型的低轨卫星钟差的确定方法及系统
CN116893438B (zh) * 2023-09-11 2023-12-01 中国科学院国家授时中心 顾及钟差模型的低轨卫星钟差的确定方法及系统
CN117310755A (zh) * 2023-11-30 2023-12-29 中国人民解放军国防科技大学 卫星导航信号可信认证协议及终端可信定位的方法与装置
CN117310755B (zh) * 2023-11-30 2024-02-20 中国人民解放军国防科技大学 卫星导航信号可信认证协议及终端可信定位的方法与装置
CN117890936A (zh) * 2024-03-13 2024-04-16 中国科学院国家授时中心 一种低轨卫星在轨实时星间时间传递方法和系统
CN117890936B (zh) * 2024-03-13 2024-06-04 中国科学院国家授时中心 一种低轨卫星在轨实时星间时间传递方法和系统
CN118129767A (zh) * 2024-05-07 2024-06-04 武汉大学 一种动力学约束的低轨卫星gnss实时精密定轨方法及系统

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