阅读说明：本技术 一种高轨卫星厘米级定轨系统与方法 (Centimeter-level orbit determination system and method for high orbit satellite ) 是由 蒙艳松 周泉 边朗 王瑛 张蓬 严涛 田野 于 2021-07-21 设计创作，主要内容包括：本发明公开了一种高轨卫星厘米级精密定轨系统与方法,可以实现高轨卫星厘米级精密轨道确定,满足当前高轨卫星应用对厘米级高精度轨道的需求。从观测方程层面直接将低轨卫星观测方程和地面监测站观测方程进行融合,通过建立合理正确的函数关系,联合估计北斗/GNSS轨道参数、低轨卫星轨道参数和高轨卫星轨道参数,进而通过残差检验、迭代循环的方式得到北斗/GNSS卫星、低轨卫星、高轨卫星的最优估值,最后再通过轨道积分,得到北斗/GNSS卫星、低轨卫星、高轨卫星的厘米级精密轨道。(The invention discloses a centimeter-level precision orbit determination system and method for a high-orbit satellite, which can be used for determining centimeter-level precision orbits of the high-orbit satellite and meeting the requirements of current high-orbit satellite application on centimeter-level high-precision orbits. The method comprises the steps of directly fusing a low-orbit satellite observation equation and a ground monitoring station observation equation from an observation equation layer, jointly estimating Beidou/GNSS orbit parameters, low-orbit satellite orbit parameters and high-orbit satellite orbit parameters by establishing a reasonable and correct functional relationship, obtaining optimal estimated values of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite through residual error detection and iterative cycle, and finally obtaining centimeter-level precise orbits of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite through orbit integration.)

1. The utility model provides a centimeter level orbit determination system of high orbit satellite which characterized in that: the orbit determination system comprises a Beidou/GNSS navigation satellite, a high orbit satellite, a low orbit satellite constellation, a ground monitoring station and a ground control center;

the Beidou/GNSS navigation satellite generates a downlink navigation signal under the control of the satellite-borne atomic clock and continuously broadcasts the downlink navigation signal to the near-earth users;

the high orbit satellite is provided with a high stability atomic clock and a navigation signal generating unit, and the navigation signal generating unit can generate a downlink navigation signal under the control of a time-frequency reference provided by the high stability atomic clock;

the low-earth-orbit satellite constellation comprises more than two low-earth-orbit satellites, one-time coverage or more than two-time coverage of the high-earth-orbit satellites can be realized, the low-earth-orbit satellites are provided with satellite-borne GNSS receivers, and the GNSS receivers can receive Beidou/GNSS navigation satellite downlink navigation signals and high-earth-orbit satellite downlink navigation signals; the low earth orbit satellites are provided with inter-satellite links, and the low earth orbit satellite observation data can be transmitted among the low earth orbit satellites in real time through the inter-satellite links; the low-orbit satellite is provided with a data downloading link and can transmit the low-orbit satellite observation data to the ground control center in real time;

the ground monitoring station is provided with a high-precision GNSS monitoring receiver, can receive Beidou/GNSS downlink navigation signals and downlink navigation signals broadcast by high-orbit satellites, generates observation data of the ground monitoring station, and transmits the generated observation data of the ground monitoring station to a ground control center in real time;

the ground control center comprises a data management subsystem and a data processing subsystem, wherein the data management subsystem is used for receiving, storing and managing low-orbit satellite observation data and ground monitoring station observation data; and the data processing subsystem is used for carrying out data processing on the observation data of the ground monitoring station and the observation data of the low-orbit satellite to generate the centimeter-level precision orbit of the high-orbit satellite.

2. The centimeter-scale orbit determination system for high-orbit satellites according to claim 1, characterized in that:

the Beidou/GNSS navigation satellite comprises at least one of a China Beidou system, an American GPS system, a Russian GLONASS system and a European Union GALILEO system; the near-earth user refers to a low-earth orbit satellite constellation and a ground monitoring station.

3. The centimeter-scale orbit determination system for high-orbit satellites according to claim 1, characterized in that:

the high-stability atomic clock-second stability to hundred-second stability of the high-orbit satellite configuration is better than 1e-12 magnitude, and the ten-thousand-second stability is better than 1e-14 magnitude; the high orbit satellite continuously broadcasts the generated downlink navigation signal to the near-earth users; the number of visible satellites (the elevation angle is larger than 7 degrees) of the high-orbit satellite at any moment in the low-orbit satellite constellation is not less than 1.

4. The centimeter-scale orbit determination system for high-orbit satellites according to claim 1, characterized in that:

the low earth orbit satellite observation data comprises two parts of contents, wherein one part of contents are pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after a low earth orbit satellite-borne GNSS receiver receives a Beidou/GNSS navigation satellite downlink navigation signal; the other part of the content is pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after a low-orbit satellite-borne GNSS receiver receives a high-orbit satellite downlink navigation signal; the method comprises the steps that a low earth orbit satellite-borne GNSS receiver receives a Beidou/GNSS navigation satellite downlink navigation signal, then generated pseudo-range observation data, carrier phase observation data and Doppler observation data are called low earth orbit satellite observation data A, the low earth orbit satellite-borne GNSS receiver receives the high earth orbit satellite downlink navigation signal, and then generated pseudo-range observation data, carrier phase observation data and Doppler observation data are called low earth orbit satellite observation data B.

5. The centimeter-scale orbit determination system for high-orbit satellites according to claim 1, characterized in that:

the ground monitoring station observation data comprises two parts, wherein one part is pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after a ground monitoring station high-precision GNSS monitoring receiver receives a Beidou/GNSS navigation satellite downlink navigation signal; the other part is pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after a high-precision GNSS monitoring receiver of a ground monitoring station receives a high-orbit satellite downlink navigation signal; the method comprises the steps that a ground monitoring station high-precision GNSS monitoring receiver receives a Beidou/GNSS navigation satellite downlink navigation signal, then generated pseudo-range observation data, carrier phase observation data and Doppler observation data are called ground monitoring station observation data A, the ground monitoring station high-precision GNSS monitoring receiver receives a high-orbit satellite downlink navigation signal, and then generated pseudo-range observation data, carrier phase observation data and Doppler observation data are called ground monitoring station observation data B.

6. The centimeter-scale orbit determination system for high-orbit satellites according to claim 1, characterized in that:

the data processing subsystem processes data by utilizing observation data of a ground monitoring station and observation data of a low earth orbit satellite, and two methods for generating centimeter-level precision orbits of high earth orbit satellites and precision clock errors are provided, wherein the first method is a high-middle-low earth integrated precision orbit determination and time synchronization method, and the other method is a high-middle-low earth integrated precision orbit determination and time synchronization method, and the steps of the high-middle-low earth integrated precision orbit determination and time synchronization method comprise:

firstly, establishing an error equation of a ground monitoring station for a Beidou/GNSS navigation satellite and a high-orbit satellite observation model;

the error equation of the ground monitoring station to the observation model of the Beidou/GNSS navigation satellite and the high orbit satellite is as follows:

v_sta＝F(X_GNSS，X_HEO，X_{sta_y}，X_{sta_n}，t_sta)-obs_sta

in the formula, v_staRepresenting the residual error of the ground monitoring station relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high orbit satellite; f (X)_GNSS，X_HEo，X_{sta_y}，X_{sta_n}，t_sta) Represents X_GNSS，X_HEO，X_{sta_y}，X_{sta_n}，t_staAnd obs_staThe functional relationship of (a); obs_staThe method comprises the steps that observation data of a ground monitoring station on a Beidou/GNSS navigation satellite and a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_GNSSExpressing the dynamic parameters of the Beidou/GNSS satellite, including the initial state vector of the Beidou/GNSS satellite, the atmospheric resistance parameter, the light pressure parameter and the empirical force parameter; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{sta_y}Parameters related to the coordinates of the ground monitoring station are represented, and the parameters comprise the coordinates of the measuring station, the earth solid tide correction and the UT1 change rate; x_{sta_n}Parameters irrelevant to the coordinates of the ground monitoring station are represented, and the parameters comprise a receiver clock error of the ground monitoring station, a Beidou/GNSS satellite clock error, a high orbit satellite clock error, an ambiguity parameter, a troposphere parameter and an ionosphere parameter; t is t_staTo representObserving epochs by a ground monitoring station;

secondly, establishing an error equation of the low-orbit satellite to the Beidou/GNSS navigation satellite and the high-orbit satellite observation model;

the error equation of the low-orbit satellite to the Beidou/GNSS navigation satellite and the high-orbit satellite observation model is expressed as follows:

v_leo＝G(X_GNSS，X_HEO，X_LEO，X_{leo_y}，X_{leo_n}，t_leo)-obs_leo

in the formula, v_leoRepresenting the residual error of the low-orbit satellite relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high-orbit satellite; g (X)_GNSS，X_HEO，X_LEO，X_{leo_y}，X_{leo_n}，t_leo) Represents X_GNSS，X_HEO，X_LEO，X_{leo_y}，X_{leo_n}，t_leoAnd obs_leoThe functional relationship of (a); obs_leoData representing low-earth-orbit satellite observation data to Beidou/GNSS navigation satellite and high-earth-orbit satellite observation data, including pseudo-range observation data, carrier phase observation data and Doppler observation data, X_GNSSExpressing Beidou/GNSS satellite dynamic parameters including Beidou/GNSS satellite initial state vectors, atmospheric resistance parameters, light pressure parameters and empirical force parameters; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_LEORepresenting dynamic parameters of the low-orbit satellite, including an initial state vector of the low-orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{leo_y}Representing a low-orbit satellite coordinate parameter, X_{leo_n}Parameters irrelevant to the low-orbit satellite coordinates are represented, and the parameters comprise low-orbit satellite borne receiver clock error, Beidou/GNSS satellite clock error, high-orbit satellite clock error, ambiguity parameters and ionosphere parameters; t is t_leoRepresenting a low earth orbit satellite observation epoch;

thirdly, the error equation established in the first step is in the approximate value of the parameter to be estimated And (3) performing Taylor formula expansion to obtain:

fourthly, the error equation established in the second step is processed into an approximate value of the parameter to be estimated And (3) performing Taylor formula expansion to obtain:

in the formula, dX_GNSS、dX_HEO、dX_{sta_y}、dX_{sta_n}、dX_LEO、dX_{leo_y}、dX_{leo_n}Representing the number of corrections of the parameter to be estimated;

fifthly, obtaining the optimal estimated value of the parameter correction number to be estimated by adopting least square estimation

Sixthly, the initial value of the parameter to be estimated is obtained And parameters to be estimatedNumber correction number dX_GNSS、dX_HEO、dX_{sta_y}、dX_{sta_n}、dX_LEO、dX_{leo_y}、dX_{leo_n}And adding to obtain the optimal estimation value of the parameter to be estimated.

7. The centimeter-scale orbit determination system for high-orbit satellites according to claim 6, characterized in that:

the method for precisely determining the orbit of the single system of the high-orbit satellite comprises the following steps:

the method comprises the steps that firstly, a Beidou/GNSS precision orbit, a precision clock error and a ground monitoring station precision coordinate file are obtained from an international IGS data center or a global research institute; acquiring a low-orbit satellite precision orbit file from a low-orbit satellite constellation operation control mechanism;

secondly, establishing an equation of the observation error of the ground monitoring station to the high orbit satellite, wherein the equation of the observation error of the ground monitoring station to the high orbit satellite is expressed as follows:

v_sta ^GEO＝F^GEO(X_HEO，t_sta)-obs_sta ^GEO

in the formula, v_sta ^GEORepresenting the residual error of the ground monitoring station to the high orbit satellite observation equation; f^GEO(X_HEO，t_sta) Represents X_HEOAnd obs_sta ^GEOThe functional relationship of (a); obs_sta ^GEOThe method comprises the steps that observation data of a ground monitoring station on a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_staRepresenting an observation epoch of a ground monitoring station;

thirdly, establishing an equation of the observation error of the low-orbit satellite to the high-orbit satellite, wherein the equation of the observation error of the low-orbit satellite to the high-orbit satellite is expressed as follows:

v_leo ^GEO＝G^GEO(X_HEO，t_leo)-obs_leo ^GEO

in the formula, v_leo ^GEORepresenting low earth orbit satellite pairsResidual errors of the high-orbit satellite observation equation; g^GEO(X_HEO，t_leo) Represents X_HEOAnd obs_leo ^GEOThe functional relationship of (a); obs_leo ^GEOThe method comprises the steps that observation data of a low-orbit satellite to a high-orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_leoRepresenting a low earth orbit satellite observation epoch;

fourthly, approximating the error equation obtained in the second step to the parameter to be estimatedAnd (3) performing Taylor formula expansion to obtain:

fifthly, approximating the error equation obtained in the third step to the parameter to be estimatedAnd (3) performing Taylor formula expansion to obtain:

in the formula, dX_HEORepresenting the number of corrections of the parameter to be estimated;

sixthly, obtaining the optimal estimated value of the parameter correction number to be estimated by adopting least square estimation

Seventhly, the initial value of the parameter to be estimated is obtainedAnd the number of parameter corrections to be estimatedAnd adding to obtain the optimal estimation value of the parameter to be estimated.

8. A centimeter-level orbit determination method for high orbit satellites is characterized by comprising the following steps:

1) carrying a high-stability atomic clock and a navigation signal generating unit on a high-orbit satellite, generating a downlink navigation signal under the control of a time-frequency reference provided by the atomic clock, and continuously broadcasting the generated downlink navigation signal to a near-earth user;

2) carrying a high-precision satellite-borne GNSS receiver on a low-orbit satellite, receiving and storing downlink navigation signals broadcast by a Beidou/GNSS navigation satellite and a high-orbit satellite, and then injecting observation data of the low-orbit satellite to a ground control center through an inter-satellite link of the low-orbit satellite;

3) a high-precision GNSS monitoring receiver is arranged at a ground monitoring station, receives downlink navigation signals of a Beidou/GNSS navigation satellite and a high orbit satellite, and transmits observation data of the ground monitoring station to a ground control center in real time;

4) and collecting, summarizing and storing low-orbit satellite observation data and ground monitoring station observation data in a ground control center, and processing the data to generate the centimeter-level precision orbit of the high-orbit satellite.

9. The centimeter-level orbit determination method for the high-orbit satellite according to claim 8, characterized in that:

in the step 4), the data processing method includes:

1) the ground control center collects the observation data of the ground monitoring station and the observation data of the low-orbit satellite;

2) performing cycle slip detection and gross error elimination on the observation data of the ground monitoring station and the observation data of the low-orbit satellite respectively to obtain the observation data of the ground monitoring station and the observation data of the low-orbit satellite with a ambiguity mark and a gross error mark;

3) and establishing an observation error equation of the ground monitoring station by utilizing the observation data of the ground monitoring station obtained by the second step of processing:

v_sta＝F(X_GNSS，X_HEO，X_{sta_y}，X_{sta_n}，t_sta)-obs_sta

in the formula, v_staRepresenting the residual error of the ground monitoring station relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high orbit satellite; f () represents X_GNSS，X_HEO，X_{sta_y}，X_{sta_n}，t_staAnd obs_staThe functional relationship of (a); obs_staThe method comprises the steps that observation data of a ground monitoring station on a Beidou/GNSS navigation satellite and a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_GNSSExpressing the dynamic parameters of the Beidou/GNSS satellite, including the initial state vector of the Beidou/GNSS satellite, the atmospheric resistance parameter, the light pressure parameter and the empirical force parameter; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{sta_y}Parameters related to the coordinates of the ground monitoring station are represented, and the parameters comprise the coordinates of the measuring station, the earth solid tide correction and the UT1 change rate; x_{sta_n}Parameters irrelevant to the coordinates of the ground monitoring station are represented, and the parameters comprise a receiver clock error of the ground monitoring station, a Beidou/GNSS satellite clock error, a high orbit satellite clock error, an ambiguity parameter, a troposphere parameter and an ionosphere parameter; t is t_staRepresenting the observation epoch of the ground monitoring station.

4) And establishing a low-orbit satellite observation error equation by using the low-orbit satellite observation data obtained by the second step of processing:

v_leo＝G(X_GNSS，X_HEO，X_LEO，X_{leo_y}，X_{leo_n}，t_leo)-obs_leo

in the formula, v_leoRepresenting the residual error of the low-orbit satellite relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high-orbit satellite; g () represents X_GNSS，X_HEO，X_LEO，X_{leo_y}，X_{leo_n}，t_leoAnd obs_leoThe functional relationship of (a); obs_leoThe method comprises the steps that observation data of a low-orbit satellite to a Beidou/GNSS navigation satellite and a high-orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_GNSSThe same as above; x_HEOThe same as above; x_LEORepresenting dynamic parameters of the low-orbit satellite, including an initial state vector of the low-orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{leo_y}Representing low-orbit satellite coordinate parameters, including low-orbit satellite coordinates; x_{leo_n}Parameters irrelevant to the low-orbit satellite coordinates are represented, and the parameters comprise low-orbit satellite borne receiver clock error, Beidou/GNSS satellite clock error, high-orbit satellite clock error, ambiguity parameters and ionosphere parameters; t is t_leoRepresenting the low earth orbit satellite observation epoch.

5) Using Taylor formula to make error equations in step 3 and step 4 in initial value of parameter to be estimatedAnd (3) expanding the initial value to a first-order term, and simultaneously endowing corresponding prior constraints to the initial value:

in the formula, dX_GNSS、dX_HEO、dX_sta__y、dX_{sta_n}、dX_LEO、dX_{leo_y}、dX_{leo_n}Representing the number of corrections of the parameter to be estimated;

6) obtaining the optimal estimation value of the parameter correction number to be estimated by using least square estimation While using the initial values Recovering to obtain the optimal estimated value of the parameter to be estimated;

7) after parameter estimation is completed, updating a coordinate of a survey station, a clock error of a receiver of the survey station, a troposphere delay parameter of the survey station, a clock error parameter of a low earth orbit satellite receiver, an initial state vector and a kinetic parameter of a Beidou/GNSS navigation satellite, an initial state vector and a kinetic parameter of a low earth orbit satellite, and an initial state vector and a kinetic parameter of a high earth orbit satellite;

8) bringing an estimated value of a parameter to be estimated into an error equation, calculating a residual error, simultaneously carrying out search and inspection on the residual errors of all epochs of all satellites, and re-marking cycle slip information and gross error information existing in the observed quantity until the residual error is smaller than a set threshold value and then jumping out;

9) and generating centimeter-level precision orbit position time sequences of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite through orbit integration based on the initial state vectors and the kinetic parameter information of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite which are finally estimated.

10. The centimeter-level orbit determination method for the high-orbit satellite according to claim 8, characterized in that:

in the step 4), the data processing method includes:

1) the method comprises the steps that a ground control center collects ground monitoring station observation data B, wherein the ground monitoring station observation data B are observation data generated by a ground monitoring station receiving high-orbit satellite downlink navigation signals and comprise pseudo-range observation data, carrier phase observation data and Doppler observation data;

2) the method comprises the steps that a ground control center collects low-orbit satellite observation data B, wherein the low-orbit satellite observation data B are observation data generated by a low-orbit satellite receiving a high-orbit satellite downlink navigation signal and comprise pseudo-range observation data, carrier phase observation data and Doppler observation data;

3) the ground control center acquires a Beidou/GNSS precision track, precision clock error and a ground monitoring station precision coordinate file;

4) the ground control center acquires a low-orbit satellite precision orbit and a precision clock error file;

5) performing cycle slip detection and gross error elimination on the observation data B of the ground monitoring station in the step 1 and the observation data B of the low-orbit satellite in the step 2 respectively to obtain observation data B of the ground monitoring station and observation data B of the low-orbit satellite with a ambiguity mark and a gross error mark;

6) forecasting an orbit by using a high-orbit satellite or generating initial state vectors and kinetic parameter information of a high-orbit satellite reference moment by using low-precision orbit information of the high-orbit satellite through orbit fitting;

7) generating an orbit position time sequence of the high orbit satellite through orbit integration by using the generated initial state vector and the dynamic parameter information of the high orbit satellite;

8) and (5) establishing an observation error equation of the ground monitoring station by utilizing the observation data B of the ground monitoring station obtained by the processing of the step 5:

v_sta ^GEO＝F^GEO(X_HEO，t_sta)-obs_sta ^GEO

in the formula, v_sta ^GEORepresenting the residual error of the ground monitoring station to the high orbit satellite observation equation; f^GEO() Represents X_HEOAnd obs_sta ^GEOThe functional relationship of (a); obs_sta ^GEOThe method comprises the steps that observation data of a ground monitoring station on a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_staRepresenting the observation epoch of the ground monitoring station.

9) And (3) establishing an observation error equation of the low-orbit satellite by using the low-orbit satellite observation data B obtained by the processing of the step 5:

v_leo ^GEO＝G^GEO(X_HEO，t_leo)-Obs_leo ^GEO

in the formula, v_leo ^GEORepresenting the residual error of the observation equation of the low-orbit satellite to the high-orbit satellite; g^GEO() Represents X_HEOAnd obs_leo ^GEOThe functional relationship of (a); obs_leo ^GEOThe method comprises the steps that observation data of a low-orbit satellite to a high-orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_leoRepresenting the low earth orbit satellite observation epoch.

10) Using Taylor formula to make error equation be in initial value of parameter to be estimatedAnd (3) expanding the initial value to a first-order term, and simultaneously endowing corresponding prior constraints to the initial value:

in the formula, dX_HEORepresenting the number of corrections of the parameter to be estimated;

11) and then the least square estimation is used to obtain the estimation value of the parameter correction number to be estimatedWhile using the initial valuesRecovering to obtain the optimal estimated value of the parameter to be estimated;

12) after parameter estimation is completed, updating the initial state vector and the dynamic parameters of the high orbit satellite;

13) bringing an estimated value of a parameter to be estimated into an error equation, calculating a residual error, simultaneously carrying out search and inspection on the residual errors of all observation epochs, and re-marking cycle slip information and gross error information existing in the observed quantity;

14) repeating the steps 8 to 13 until the residual error is smaller than a set threshold value, and jumping out;

15) and generating a centimeter-level precision orbit position time sequence of the high-orbit satellite through orbit integration based on the initial state vector and the dynamic parameter information of the high-orbit satellite obtained by final estimation.

Technical Field

The invention belongs to the technical field of satellite navigation, and particularly relates to a centimeter-level precision orbit determination system and method for a high-orbit satellite.

Background

The aerospace development of China is different day by day in the last thirty years, and various artificial satellites play an important role in the aspects of national economic development, social production and life, national defense safety construction and the like of China and are also important marks for China to step towards the strong nation of the world. With the continuous development and progress of the aerospace technology, the satellite has increasingly prominent functions in various fields, such as communication navigation, remote sensing detection, meteorological research, military reconnaissance, deep space detection and the like, and becomes an indispensable information tool in various industries. The artificial satellites are classified into low-orbit satellites, medium-orbit satellites, and high-orbit satellites according to the orbital altitude. The orbit precision of the satellite is used as a space reference of various satellite services, the continuity, the availability and the application level of the satellite services are directly influenced, and the development and the expansion potential of potential users and markets are determined to a certain extent.

Satellites with orbital altitudes below 2000km are generally referred to as low-orbit satellites, those with orbital altitudes between 2000km and 35786km are medium-orbit satellites, and those with orbital altitudes greater than 35786km are high-orbit satellites. Currently, low earth orbit satellites are mostly applied to earth observation satellites, space stations and next-generation communication constellations represented by 'star chains'; the medium orbit satellite is generally applied to navigation satellite constellations, such as a Beidou system, a GPS system in the United states, a GALILEO system in the European Union and the like in China; due to the unique high-orbit characteristic and the static earth characteristic, one high-orbit satellite can cover almost one third of the earth, is more and more widely applied to various fields such as communication, monitoring, weather, astronomy, deep space exploration and the like, has irreplaceable functions of medium and low orbits, and becomes the most important orbit resource of the earth space section.

Compared with a high-orbit satellite, most of the current middle and low-orbit satellites are provided with satellite-borne GNSS receivers, and by means of pseudo-range and phase observation data of the satellite-borne GNSS receivers, real-time or afterwards centimeter-level precision orbit determination of the middle and low-orbit satellites can be realized, and the requirement of high-precision orbit precision is met. For the problem of high orbit satellite orbit determination, the ground station tracking mode adopted by the traditional orbit determination has complex facilities, high cost and low precision, is limited by the restriction of China's territory, and cannot be used for laying tracking stations in foreign regions. If a similar mode of carrying a satellite-borne GNSS receiver with a medium-low orbit satellite is adopted, because the operation orbit of the high-orbit satellite is higher than the orbit of the GNSS satellite, and the signal emission direction of the GNSS navigation satellite is pointed to the center of the earth, the problem that the satellite-borne GNSS receiver of the high-orbit satellite receives an edge signal emitted by the navigation satellite on the other side of the earth is caused, the number of visible GNSS satellites of the high-orbit satellite is too small, and the signal to noise ratio is too low is caused, the high-orbit satellite orbit determination accuracy based on the satellite-borne GNSS receiver is seriously influenced, and the application potential of the high-orbit satellite in the aspects of communication, navigation, remote sensing, reconnaissance, scientific research and the like is restricted.

Disclosure of Invention

The technical problems solved by the invention are as follows: aiming at the requirement of a high-orbit satellite on a centimeter-level high-precision orbit, combining the development prospect of the current low-orbit satellite constellation, fully utilizing multisystem multilevel observation data of high, medium and low regions, providing a centimeter-level precision orbit determination system and method suitable for the high-orbit satellite, and meeting the requirement of the current high-orbit satellite application on the centimeter-level high-precision orbit.

In order to achieve the purpose, the invention discloses a centimeter-level precision orbit determination system and method for a high orbit satellite.

A centimeter-level precision orbit determination system for a high orbit satellite comprises a Beidou/GNSS navigation satellite, the high orbit satellite, a low orbit satellite constellation, a ground monitoring station and a ground control center;

the Beidou/GNSS navigation satellite generates a downlink navigation signal under the control of the satellite-borne atomic clock and continuously broadcasts the downlink navigation signal to a near-earth user to provide positioning, speed measuring and time service, and comprises at least one of a China Beidou system, an American GPS system, a Russian GLONASS system and an European Union GALILEO system;

the near-earth user refers to a low-earth orbit satellite constellation and a ground monitoring station;

the high orbit satellite is provided with a high-stability atomic clock for providing a high-precision time-frequency reference, the second stability to the hundred second stability of the high-stability atomic clock is better than 1e-12 magnitude, and the ten thousand second stability is better than 1e-14 magnitude; the high orbit satellite is also provided with a navigation signal generating unit which can generate a downlink navigation signal under the control of a time-frequency reference provided by a high-stability atomic clock and continuously broadcast the generated downlink navigation signal to a near-earth user;

the low-orbit satellite constellation comprises more than two low-orbit satellites, and can realize one-time coverage and more than two-time coverage on the high-orbit satellites, namely the number of visible satellites (the elevation angle is more than 7 ℃) on the high-orbit satellites at any moment is not less than 1; all low-earth orbit satellites are provided with high-precision satellite-borne GNSS receivers, and the GNSS receivers can receive Beidou/GNSS navigation satellite downlink navigation signals and high-earth orbit satellite downlink navigation signals; the low earth orbit satellites are provided with inter-satellite links, and the low earth orbit satellite observation data can be transmitted among the low earth orbit satellites in real time through the inter-satellite links; the low-orbit satellite is provided with a data downloading link and can transmit the low-orbit satellite observation data to the ground control center in real time; the low earth orbit satellite observation data comprises two parts of contents, wherein one part of contents are pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after a low earth orbit satellite-borne GNSS receiver receives a Beidou/GNSS navigation satellite downlink navigation signal; the other part of the content is pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after a low-orbit satellite-borne GNSS receiver receives a high-orbit satellite downlink navigation signal; receiving a Beidou/GNSS navigation satellite downlink navigation signal by a low earth orbit satellite-borne GNSS receiver, then generating pseudo-range observation data, carrier phase observation data and Doppler observation data called low earth orbit satellite observation data A, receiving the high earth orbit satellite downlink navigation signal by the low earth orbit satellite-borne GNSS receiver, then generating pseudo-range observation data, carrier phase observation data and Doppler observation data called low earth orbit satellite observation data B, namely the low earth orbit satellite observation data A is the low earth orbit satellite downlink navigation signal received by the low earth orbit satellite-borne GNSS receiver, and then generating pseudo-range observation data, carrier phase observation data and Doppler observation data; the low earth orbit satellite observation data B is pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after a low earth orbit satellite-borne GNSS receiver receives a high earth orbit satellite downlink navigation signal;

the ground monitoring station is provided with a high-precision GNSS monitoring receiver, can receive Beidou/GNSS downlink navigation signals and downlink navigation signals broadcast by high-orbit satellites, generates observation data of the ground monitoring station, and transmits the generated observation data of the ground monitoring station to a ground control center in real time; the ground monitoring station observation data comprises two parts, wherein one part is pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after a ground monitoring station high-precision GNSS monitoring receiver receives a Beidou/GNSS navigation satellite downlink navigation signal; the other part is pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after a high-precision GNSS monitoring receiver of a ground monitoring station receives a high-orbit satellite downlink navigation signal; receiving a Beidou/GNSS navigation satellite downlink navigation signal by a ground monitoring station high-precision GNSS monitoring receiver, then generating pseudo-range observation data, carrier phase observation data and Doppler observation data called ground monitoring station observation data A, receiving the high-orbit satellite downlink navigation signal by the ground monitoring station high-precision GNSS monitoring receiver, then generating pseudo-range observation data, carrier phase observation data and Doppler observation data called ground monitoring station observation data B, namely the ground monitoring station observation data A means receiving the Beidou/GNSS navigation satellite downlink navigation signal by the ground monitoring station high-precision GNSS monitoring receiver, and then generating pseudo-range observation data, carrier phase observation data and Doppler observation data; the observation data B of the ground monitoring station refers to pseudo-range observation data, carrier phase observation data and Doppler observation data which are generated after the ground monitoring station high-precision GNSS monitoring receiver receives the high-orbit satellite downlink navigation signals;

the ground control center comprises a data management subsystem and a data processing subsystem, wherein the data management subsystem is used for receiving, storing and managing low-orbit satellite observation data; the data management subsystem is used for receiving, storing and managing observation data of the ground monitoring station; the data management subsystem is used for receiving, storing and managing the precise orbit and the precise clock error of the high orbit satellite; the data processing subsystem performs data processing by utilizing observation data of a ground monitoring station and observation data of a low-orbit satellite to generate centimeter-level precision orbit and precision clock error of the high-orbit satellite;

the data processing subsystem processes data by utilizing observation data of a ground monitoring station and observation data of a low earth orbit satellite, and two methods for generating centimeter-level precision orbits of high earth orbit satellites and precision clock errors are provided, wherein the first method is a high-middle-low earth integrated precision orbit determination and time synchronization method, and the other method is a high-middle-low earth integrated precision orbit determination and time synchronization method, and the steps of the high-middle-low earth integrated precision orbit determination and time synchronization method comprise:

firstly, establishing an error equation of a ground monitoring station for a Beidou/GNSS navigation satellite and a high-orbit satellite observation model;

the error equation of the ground monitoring station to the observation model of the Beidou/GNSS navigation satellite and the high orbit satellite is as follows:

v_sta＝F(X_GNSS,X_HEO,X_{sta_y},X_{sta_n},t_sta)-obs_sta

in the formula, v_staRepresenting the residual error of the ground monitoring station relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high orbit satellite; f (X)_GNSS,X_HEO,X_{sta_y},X_{sta_n},t_sta) Represents X_GNsS,X_HEO,X_{sta_y},X_{sta_n},t_staAnd obs_staThe functional relationship of (a); obs_staThe method comprises the steps that observation data of a ground monitoring station on a Beidou/GNSS navigation satellite and a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_GNSSExpressing the dynamic parameters of the Beidou/GNSS satellite, including the initial state vector of the Beidou/GNSS satellite, the atmospheric resistance parameter, the light pressure parameter and the empirical force parameter; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{sta_y}Is shown andparameters of the ground monitoring station coordinates comprise the coordinates of the measuring station, the earth solid tide correction and the UT1 change rate; x_{sta_n}Parameters irrelevant to the coordinates of the ground monitoring station are represented, and the parameters comprise a receiver clock error of the ground monitoring station, a Beidou/GNSS satellite clock error, a high orbit satellite clock error, an ambiguity parameter, a troposphere parameter and an ionosphere parameter; t is t_staRepresenting an observation epoch of a ground monitoring station;

secondly, establishing an error equation of the low-orbit satellite to the Beidou/GNSS navigation satellite and the high-orbit satellite observation model;

the error equation of the low-orbit satellite to the Beidou/GNSS navigation satellite and the high-orbit satellite observation model is expressed as follows:

v_leo＝G(X_GNSS,X_HEO,X_LEO,X_{leo_y},X_{leo_n},t_leo)-obs_leo

in the formula, v_leoRepresenting the residual error of the low-orbit satellite relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high-orbit satellite; g (X)_GNSS,X_HEO,X_LEO,X_{leo_y},X_{leo_n},t_leo) Represents X_GNSS,X_HEO,X_LEO,X_{leo_y},X_{leo_n},t_leoAnd obs_leoThe functional relationship of (a); obs_leoData representing low-earth-orbit satellite observation data to Beidou/GNSS navigation satellite and high-earth-orbit satellite observation data, including pseudo-range observation data, carrier phase observation data and Doppler observation data, X_GNSSExpressing the dynamic parameters of the Beidou/GNSS satellite, including the initial state vector of the Beidou/GNSS satellite, the atmospheric resistance parameter, the light pressure parameter and the empirical force parameter; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_LEORepresenting dynamic parameters of the low-orbit satellite, including an initial state vector of the low-orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{leo_y}Representing the coordinate parameters of the low orbit satellite; x_{leo_n}Parameters irrelevant to the low-orbit satellite coordinates are represented and comprise clock error of a low-orbit satellite borne receiver, clock error of a Beidou/GNSS satellite, clock error of a high-orbit satellite and fuzzyDegree parameters and ionospheric parameters; t is t_leoRepresenting a low earth orbit satellite observation epoch;

thirdly, the error equation established in the first step is in the approximate value of the parameter to be estimated And (3) performing Taylor formula expansion to obtain:

fourthly, the error equation established in the second step is processed into an approximate value of the parameter to be estimated And (3) performing Taylor formula expansion to obtain:

in the formula, dX_GNSS、dX_HEO、dX_{sta_y}、dX_{sta_n}、dX_LEO、dX_{leo_y}、dX_{leo_n}Representing the number of corrections of the parameter to be estimated;

fifthly, obtaining the optimal estimated value of the parameter correction number to be estimated by adopting least square estimation

Sixthly, the initial value of the parameter to be estimated is obtained And the parameter correction dX to be estimated_GNSS、dX_HEO、dX_{sta_y}、dX_{sta_n}、dX_LEO、dX_{leo_y}、dX_{leo_n}Adding to obtain the optimal estimated value of the parameter to be estimated;

the method for precisely determining the orbit of the single system of the high-orbit satellite comprises the following steps:

the method comprises the steps that firstly, a Beidou/GNSS precision orbit, a precision clock error and a ground monitoring station precision coordinate file are obtained from an international IGS data center or a global research institute; acquiring a low-orbit satellite precision orbit file from a low-orbit satellite constellation operation control mechanism;

secondly, establishing an equation of the observation error of the ground monitoring station to the high orbit satellite, wherein the equation of the observation error of the ground monitoring station to the high orbit satellite is expressed as follows:

v_sta ^GEO＝F^GEO(X_HEO,t_sta)-obs_sta ^GEO

in the formula, v_sta ^GEORepresenting the residual error of the ground monitoring station to the high orbit satellite observation equation; f^GEO(X_HEO,t_sta) Represents X_HEOAnd Obs_sta ^GEOThe functional relationship of (a); obs_sta ^GEOThe method comprises the steps that observation data of a ground monitoring station on a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_staRepresenting an observation epoch of a ground monitoring station;

thirdly, establishing an equation of the observation error of the low-orbit satellite to the high-orbit satellite, wherein the equation of the observation error of the low-orbit satellite to the high-orbit satellite is expressed as follows:

v_leo ^GEO＝G^GEO(X_HEO,t_leo)-obs_leo ^GEO

in the formula, v_leo ^GEOTo representResidual errors of low-orbit satellites to high-orbit satellite observation equations; g^GEO(X_HEO,t_leo) Represents X_HEOAnd obs_leo ^GEoThe functional relationship of (a); obs_leo ^GEOThe method comprises the steps that observation data of a low-orbit satellite to a high-orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_leoRepresenting a low earth orbit satellite observation epoch;

fourthly, approximating the error equation obtained in the second step to the parameter to be estimatedAnd (3) performing Taylor formula expansion to obtain:

fifthly, approximating the error equation obtained in the third step to the parameter to be estimatedAnd (3) performing Taylor formula expansion to obtain:

in the formula, dX_HEORepresenting the number of corrections of the parameter to be estimated;

sixthly, obtaining the optimal estimated value of the parameter correction number to be estimated by adopting least square estimation

Seventhly, the initial value of the parameter to be estimated is obtainedAnd the number of parameter corrections to be estimatedAnd adding to obtain the optimal estimation value of the parameter to be estimated.

A centimeter-level precision orbit determination method for high orbit satellites comprises the following steps:

1) carrying a high-stability atomic clock and a navigation signal generating unit on a high-orbit satellite, generating a downlink navigation signal under the control of a time-frequency reference provided by the atomic clock, and continuously broadcasting the generated downlink navigation signal to a near-earth user;

2) carrying a high-precision satellite-borne GNSS receiver on a low-orbit satellite, receiving and storing downlink navigation signals broadcast by a Beidou/GNSS navigation satellite and a high-orbit satellite, and then injecting observation data of the low-orbit satellite to a ground control center through an inter-satellite link of the low-orbit satellite;

3) a high-precision GNSS monitoring receiver is arranged at a ground monitoring station, receives downlink navigation signals of a Beidou/GNSS navigation satellite and a high orbit satellite, and transmits observation data of the ground monitoring station to a ground control center in real time;

4) and collecting, summarizing and storing low-orbit satellite observation data and ground monitoring station observation data in a ground control center, and generating a centimeter-level precision orbit of the high-orbit satellite through data processing.

The detailed data processing flow of high, medium and low integrated precision orbit determination and time synchronization is specifically described as follows:

1) the method comprises the steps that a ground control center collects ground monitoring station observation data and low-orbit satellite observation data, wherein the ground monitoring station observation data comprise ground monitoring station observation data A and ground monitoring station observation data B, and the low-orbit satellite observation data comprise low-orbit satellite observation data A and low-orbit satellite observation data B;

2) further, cycle slip detection and gross error elimination are respectively carried out on the observation data of the ground monitoring station and the observation data of the low-orbit satellite, so that the observation data of the ground monitoring station and the observation data of the low-orbit satellite with the ambiguity marks and the gross error marks are obtained;

3) generating a position sequence of a Beidou/GNSS satellite by utilizing the Beidou/GNSS broadcast ephemeris, and generating a group of initial state vectors and initial kinetic parameter information of the Beidou/GNSS satellite reference time through orbit fitting;

4) resolving a low-precision low-orbit satellite position sequence by utilizing a Beidou/GNSS broadcast ephemeris and low-orbit satellite observation data, and generating an initial state vector of a low-orbit satellite reference moment, initial value information of dynamic parameters and clock error of a low-orbit satellite receiver through orbit fitting;

5) forecasting an orbit by using a high-orbit satellite or generating initial state vectors and kinetic parameter information of a high-orbit satellite reference moment by using low-precision orbit information of the high-orbit satellite through orbit fitting;

6) generating orbit position time sequences of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite by using the generated initial state vectors and kinetic parameter information of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite through orbit integration;

7) and establishing an observation error equation of the ground monitoring station by utilizing the observation data of the ground monitoring station obtained by the second step of processing:

v_sta＝F(X_GNSS,X_HEO,X_{sta_y},X_{sta_n},t_sta)-obs_sta

in the formula, v_staRepresenting the residual error of the ground monitoring station relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high orbit satellite; f represents X_GNSS,X_HEO,X_{sta_y},X_{sta_n},t_staAnd obs_staThe functional relationship of (a); obs_staThe method comprises the steps that observation data of a ground monitoring station on a Beidou/GNSS navigation satellite and a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_GNSSExpressing the dynamic parameters of the Beidou/GNSS satellite, including the initial state vector of the Beidou/GNSS satellite, the atmospheric resistance parameter, the light pressure parameter and the empirical force parameter; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{sta_y}Parameters representing coordinates with a ground monitoring station, including coordinates of the station, earth solid tide correction, UT1 rate of change; x_{sta_n}Parameters irrelevant to the coordinates of the ground monitoring station are represented, and the parameters comprise a receiver clock error of the ground monitoring station, a Beidou/GNSS satellite clock error, a high orbit satellite clock error, an ambiguity parameter, a troposphere parameter and an ionosphere parameter; t is t_staRepresenting the observation epoch of the ground monitoring station.

8) And establishing a low-orbit satellite observation error equation by using the low-orbit satellite observation data obtained by the second step of processing:

v_leo＝G(X_GNSS,X_HEO,X_LEO,X_{leo_y},X_{leo_n},t_leo)-obs_leo

in the formula, v_leoRepresenting the residual error of the low-orbit satellite relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high-orbit satellite; g represents X_GNSS,X_HEO,X_LEO,X_{leo_y},X_{leo_n},t_leoAnd obs_leoThe functional relationship of (a); obs_leoThe method comprises the steps that observation data of a low-orbit satellite to a Beidou/GNSS navigation satellite and a high-orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_GNSSThe same as above; x_HEOThe same as above; x_LEORepresenting dynamic parameters of the low-orbit satellite, including an initial state vector of the low-orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{leo_y}Representing the coordinate parameters of the low orbit satellite; x_{leo_n}Parameters irrelevant to the low-orbit satellite coordinates are represented, and the parameters comprise low-orbit satellite borne receiver clock error, Beidou/GNSS satellite clock error, high-orbit satellite clock error, ambiguity parameters and ionosphere parameters; t is t_leoRepresenting the low earth orbit satellite observation epoch.

9) Using Taylor formula to make error equations in step 7 and step 8 in initial value of parameter to be estimatedAnd (3) expanding the initial value to a first-order term, and simultaneously endowing corresponding prior constraints to the initial value:

in the formula, dX_GNSS、dX_HEO、dX_{sta_y}、dX_{sta_n}、dX_LEO、dX_{leo_y}、dX_{leo_n}Representing the number of corrections of the parameter to be estimated;

10) obtaining the optimal estimation value of the parameter correction number to be estimated by using least square estimation While using the initial values Recovering to obtain the optimal estimated value of the parameter to be estimated;

11) after parameter estimation is completed, updating a coordinate of a survey station, a clock error of a receiver of the survey station, a troposphere delay parameter of the survey station, a clock error parameter of a low earth orbit satellite receiver, an initial state vector and a kinetic parameter of a Beidou/GNSS navigation satellite, an initial state vector and a kinetic parameter of a low earth orbit satellite, and an initial state vector and a kinetic parameter of a high earth orbit satellite;

12) bringing the estimated value of the parameter to be estimated into an error equation, calculating residual errors, simultaneously carrying out search and inspection on the residual errors of all epochs of all satellites, and re-marking cycle slip information and gross error information existing in the observed quantity;

13) repeating the step 7 to the step 12 until the residual error is smaller than the set threshold value, and jumping out;

14) and generating centimeter-level precision orbit position time sequences of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite through orbit integration based on the initial state vectors and the kinetic parameter information of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite which are finally estimated.

The detailed data processing flow of the high-orbit satellite single-system precise orbit determination is specifically described as follows:

1) the method comprises the steps that a ground control center collects ground monitoring station observation data B, wherein the ground monitoring station observation data B are observation data generated by a ground monitoring station receiving high-orbit satellite downlink navigation signals and comprise pseudo-range observation data, carrier phase observation data and Doppler observation data;

2) the method comprises the steps that a ground control center collects low-orbit satellite observation data B, wherein the low-orbit satellite observation data B are observation data generated by a low-orbit satellite receiving a high-orbit satellite downlink navigation signal and comprise pseudo-range observation data, carrier phase observation data and Doppler observation data;

3) the ground control center acquires a Beidou/GNSS precision track, precision clock error and a ground monitoring station precision coordinate file;

4) the ground control center acquires a low-orbit satellite precision orbit and a precision clock error file;

5) performing cycle slip detection and gross error elimination on the observation data B of the ground monitoring station in the step 1 and the observation data B of the low-orbit satellite in the step 2 respectively to obtain observation data B of the ground monitoring station and observation data B of the low-orbit satellite with a ambiguity mark and a gross error mark;

6) forecasting an orbit by using a high-orbit satellite or generating initial state vectors and kinetic parameter information of a high-orbit satellite reference moment by using low-precision orbit information of the high-orbit satellite through orbit fitting;

7) generating an orbit position time sequence of the high orbit satellite through orbit integration by using the generated initial state vector and the dynamic parameter information of the high orbit satellite;

8) and (5) establishing an observation error equation of the ground monitoring station by utilizing the observation data B of the ground monitoring station obtained by the processing of the step 5:

v_sta ^GEO＝F^GEO(X_HEO,t_sta)-obs_sta ^GEO

in the formula, v_sta ^GEORepresenting the residual error of the ground monitoring station to the high orbit satellite observation equation; f^GEO() Represents X_HEOAnd obs_sta ^GEOThe functional relationship of (a); obs_sta ^GEOThe method comprises the steps that observation data of a ground monitoring station on a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_staRepresenting the observation epoch of the ground monitoring station.

9) And (3) establishing an observation error equation of the low-orbit satellite by using the low-orbit satellite observation data B obtained by the processing of the step 5:

v_leo ^GEO＝G^GEO(X_HEO,t_leo)-obs_leo ^GEO

in the formula, v_leo ^GEORepresenting the residual error of the observation equation of the low-orbit satellite to the high-orbit satellite; g^GEO() Represents X_HEOAnd obs_leo ^GEOThe functional relationship of (a); obs_leo ^GEOThe method comprises the steps that observation data of a low-orbit satellite to a high-orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_leoRepresenting the low earth orbit satellite observation epoch.

10) Using Taylor formula to make error equation be in initial value of parameter to be estimatedAnd (3) expanding the initial value to a first-order term, and simultaneously endowing corresponding prior constraints to the initial value:

in the formula, dX_HEOIndicating changes in the parameter to be estimatedA positive number;

11) and then the least square estimation is used to obtain the estimation value of the parameter correction number to be estimatedWhile using the initial valuesRecovering to obtain the optimal estimated value of the parameter to be estimated;

12) after parameter estimation is completed, updating the initial state vector and the dynamic parameters of the high orbit satellite;

13) bringing an estimated value of a parameter to be estimated into an error equation, calculating a residual error, simultaneously carrying out search and inspection on the residual errors of all observation epochs, and re-marking cycle slip information and gross error information existing in the observed quantity;

14) repeating the steps 8 to 13 until the residual error is smaller than a set threshold value, and jumping out;

15) and generating a centimeter-level precision orbit position time sequence of the high-orbit satellite through orbit integration based on the initial state vector and the dynamic parameter information of the high-orbit satellite obtained by final estimation.

Compared with the prior art, the method disclosed by the invention has the following advantages:

(1) the method is characterized in that an atomic clock and a navigation signal generating unit are carried on a high-orbit satellite, so that the high-orbit satellite has the navigation signal generating and broadcasting capacity;

(2) the satellite-borne GNSS receiver is carried on the low-orbit satellite, receives downlink navigation signals of the Beidou/GNSS navigation satellite and the high-orbit satellite at the same time, utilizes the characteristics of high movement speed and large change of geometric configuration of the low-orbit satellite, solves the adverse effect of the static characteristic of the high-orbit satellite on precise orbit determination, obviously improves the geometric observation condition of the high-orbit satellite, and greatly improves the orbit determination precision of the high-orbit satellite, particularly the precision in the tangential direction;

(3) the method comprises the steps that navigation signals of a Beidou/GNSS navigation satellite and a high-orbit satellite are received at a ground monitoring station at the same time, and the intensity of orbit determination solution is enhanced while the orbit determination precision is improved by increasing redundant observation quantity;

(4) in an orbit determination solution strategy, a high, medium and low ground integrated precise orbit determination and time synchronization method is provided, a low orbit satellite observation equation and a ground monitoring station observation equation are directly fused from an observation equation layer, Beidou/GNSS orbit parameters, low orbit satellite orbit parameters and high orbit satellite orbit parameters are jointly estimated by establishing a reasonable and correct function relation, then the optimal estimated values of the Beidou/GNSS satellite, the low orbit satellite and the high orbit satellite are obtained through residual error detection and iterative cycle, and finally centimeter-level precise orbits of the Beidou/GNSS satellite, the low orbit satellite and the high orbit satellite are obtained through orbit integration. The method makes full use of multi-system multi-level observation data, provides more stable and reliable space-time reference, enhances the strength of orbit determination solution, and can obtain higher orbit precision.

(5) The method fixes the Beidou/GNSS precise orbit, the precise clock error, the low orbit satellite precise orbit and the precise clock error, fixes the ground station coordinate, only estimates the initial state vector and the dynamic parameter related to the high orbit satellite, greatly simplifies the high orbit satellite precise orbit determination data processing flow and greatly shortens the processing time while obtaining the high orbit satellite centimeter-grade precise orbit and the precise clock error.

(6) The invention discloses a centimeter-level precision orbit determination system and method for a high-orbit satellite.

Drawings

FIG. 1 is a schematic diagram of the centimeter-level precision orbit determination system of the high orbit satellite of the present invention;

FIG. 2 is a block diagram of a high, medium and low ground integrated precision orbit determination and time synchronization method;

fig. 3 is a block diagram of a single system precise orbit determination method for a high orbit satellite.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings.

The invention discloses a centimeter-level precision orbit determination system of a high orbit satellite, which is shown in figure 1:

1) carrying a high-stability atomic clock and a navigation signal generating unit on a high-orbit satellite, and generating a downlink navigation signal under the control of a time-frequency reference provided by the atomic clock;

2) carrying a high-precision satellite-borne GNSS receiver on a low-orbit satellite, receiving and storing downlink navigation signals broadcast by a Beidou/GNSS navigation satellite and a high-orbit satellite, and then injecting observation data of the low-orbit satellite to a ground control center through an inter-satellite link of the low-orbit satellite;

3) a high-precision GNSS monitoring receiver is arranged at a ground monitoring station, receives downlink navigation signals of a Beidou/GNSS navigation satellite and a high orbit satellite, and transmits observation data of the ground monitoring station to a ground control center in real time;

4) and collecting, summarizing and storing low-orbit satellite observation data and ground monitoring station observation data in a ground control center, and generating a centimeter-level precision orbit of the high-orbit satellite through data processing.

Fig. 2 shows a detailed data processing flow of high, medium and low integrated precision orbit determination and time synchronization, which is specifically described as follows:

1) the method comprises the steps that a ground control center collects ground monitoring station observation data and low-orbit satellite observation data, wherein the ground monitoring station observation data comprise ground monitoring station observation data A and ground monitoring station observation data B, and the low-orbit satellite observation data comprise low-orbit satellite observation data A and low-orbit satellite observation data B;

2) further, cycle slip detection and gross error elimination are respectively carried out on the observation data of the ground monitoring station and the observation data of the low-orbit satellite, so that the observation data of the ground monitoring station and the observation data of the low-orbit satellite with the ambiguity marks and the gross error marks are obtained;

3) generating a position sequence of a Beidou/GNSS satellite by utilizing the Beidou/GNSS broadcast ephemeris, and generating a group of initial state vectors and initial kinetic parameter information of the Beidou/GNSS satellite reference time through orbit fitting;

4) resolving a low-precision low-orbit satellite position sequence by utilizing a Beidou/GNSS broadcast ephemeris and low-orbit satellite observation data, and generating an initial state vector of a low-orbit satellite reference moment, initial value information of dynamic parameters and clock error of a low-orbit satellite receiver through orbit fitting;

5) forecasting an orbit by using a high-orbit satellite or generating initial state vectors and kinetic parameter information of a high-orbit satellite reference moment by using low-precision orbit information of the high-orbit satellite through orbit fitting;

6) generating orbit position time sequences of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite by using the generated initial state vectors and kinetic parameter information of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite through orbit integration;

7) and establishing an observation error equation of the ground monitoring station by utilizing the observation data of the ground monitoring station obtained by the second step of processing:

v_sta＝F(X_GNSS,X_HEO,X_{sta_y},X_{sta_n},t_sta)-obs_sta

in the formula, v_staRepresenting the residual error of the ground monitoring station relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high orbit satellite; f represents X_GNSS,X_HEO,X_{sta_y},X_{sta_n},t_staAnd obs_staThe functional relationship of (a); obs_staThe method comprises the steps that observation data of a ground monitoring station on a Beidou/GNSS navigation satellite and a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_GNSSExpressing the dynamic parameters of the Beidou/GNSS satellite, including the initial state vector of the Beidou/GNSS satellite, the atmospheric resistance parameter, the light pressure parameter and the empirical force parameter; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{sta_y}Parameters representing coordinates with a ground monitoring station, including coordinates of the station, earth solid tide correction, UT1 rate of change; x_{sta_n}Indicating independence from ground monitoring station coordinatesParameters including a ground monitoring station receiver clock error, a Beidou/GNSS satellite clock error, a high orbit satellite clock error, an ambiguity parameter, a troposphere parameter and an ionosphere parameter; t is t_staRepresenting the observation epoch of the ground monitoring station.

8) And establishing a low-orbit satellite observation error equation by using the low-orbit satellite observation data obtained by the second step of processing:

v_leo＝G(X_GNSS,X_HEO,X_LEO,X_{leo_y},X_{leo_n},t_leo)-obs_leo

in the formula, v_leoRepresenting the residual error of the low-orbit satellite relative to the observation equation of the Beidou/GNSS navigation satellite and the residual error relative to the observation equation of the high-orbit satellite; g represents X_GNSS,X_HEO,X_LEO,X_{leo_y},X_{leo_n},t_leoAnd obs_leoThe functional relationship of (a); obs_leoThe method comprises the steps that observation data of a low-orbit satellite to a Beidou/GNSS navigation satellite and a high-orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_GNSSThe same as above; x_HEOThe same as above; x_LEORepresenting dynamic parameters of the low-orbit satellite, including an initial state vector of the low-orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; x_{leo_y}Representing the coordinate parameters of the low orbit satellite; x_{leo_n}Parameters irrelevant to the low-orbit satellite coordinates are represented, and the parameters comprise low-orbit satellite borne receiver clock error, Beidou/GNSS satellite clock error, high-orbit satellite clock error, ambiguity parameters and ionosphere parameters; t is t_leoRepresenting the low earth orbit satellite observation epoch.

9) Using Taylor formula to make error equations in step 7 and step 8 in initial value of parameter to be estimatedAnd (3) expanding the initial value to a first-order term, and simultaneously endowing corresponding prior constraints to the initial value:

in the formula, dX_GNSS、dX_HEO、dX_{sta_y}、dX_{sta_n}、dX_LEO、dX_{leo_y}、dX_{leo_n}Representing the number of corrections of the parameter to be estimated;

10) obtaining the optimal estimation value of the parameter correction number to be estimated by using least square estimation While using the initial values Recovering to obtain the optimal estimated value of the parameter to be estimated;

11) after parameter estimation is completed, updating a coordinate of a survey station, a clock error of a receiver of the survey station, a troposphere delay parameter of the survey station, a clock error parameter of a low earth orbit satellite receiver, an initial state vector and a kinetic parameter of a Beidou/GNSS navigation satellite, an initial state vector and a kinetic parameter of a low earth orbit satellite, and an initial state vector and a kinetic parameter of a high earth orbit satellite;

12) bringing the estimated value of the parameter to be estimated into an error equation, calculating residual errors, simultaneously carrying out search and inspection on the residual errors of all epochs of all satellites, and re-marking cycle slip information and gross error information existing in the observed quantity;

13) repeating the step 7 to the step 12 until the residual error is smaller than the set threshold value, and jumping out;

14) and generating centimeter-level precision orbit position time sequences of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite through orbit integration based on the initial state vectors and the kinetic parameter information of the Beidou/GNSS satellite, the low-orbit satellite and the high-orbit satellite which are finally estimated.

Fig. 3 shows a detailed data processing flow of the precise orbit determination of the single system of the high orbit satellite, which is specifically described as follows:

1) the method comprises the steps that a ground control center collects ground monitoring station observation data B, wherein the ground monitoring station observation data B are observation data generated by a ground monitoring station receiving high-orbit satellite downlink navigation signals and comprise pseudo-range observation data, carrier phase observation data and Doppler observation data;

2) the method comprises the steps that a ground control center collects low-orbit satellite observation data B, wherein the low-orbit satellite observation data B are observation data generated by a low-orbit satellite receiving a high-orbit satellite downlink navigation signal and comprise pseudo-range observation data, carrier phase observation data and Doppler observation data;

3) the ground control center acquires a Beidou/GNSS precision track, precision clock error and a ground monitoring station precision coordinate file;

4) the ground control center acquires a low-orbit satellite precision orbit and a precision clock error file;

5) performing cycle slip detection and gross error elimination on the observation data B of the ground monitoring station in the step 1 and the observation data B of the low-orbit satellite in the step 2 respectively to obtain observation data B of the ground monitoring station and observation data B of the low-orbit satellite with a ambiguity mark and a gross error mark;

6) forecasting an orbit by using a high-orbit satellite or generating initial state vectors and kinetic parameter information of a high-orbit satellite reference moment by using low-precision orbit information of the high-orbit satellite through orbit fitting;

7) generating an orbit position time sequence of the high orbit satellite through orbit integration by using the generated initial state vector and the dynamic parameter information of the high orbit satellite;

8) and (5) establishing an observation error equation of the ground monitoring station by utilizing the observation data B of the ground monitoring station obtained by the processing of the step 5:

v_sta ^GEO＝F^GEO(X_HEO,t_sta)-obs_sta ^GEO

in the formula, v_sta ^GEORepresenting the residual error of the ground monitoring station to the high orbit satellite observation equation; f^GEO() Represents X_HEOAnd obs_staThe functional relationship of (a); obs_sta ^GEOThe method comprises the steps that observation data of a ground monitoring station on a high orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_staRepresenting the observation epoch of the ground monitoring station.

9) And (3) establishing an observation error equation of the low-orbit satellite by using the low-orbit satellite observation data B obtained by the processing of the step 5:

v_leo ^GEO＝G^GEO(X_HEO,t_leo)-obs_leo ^GEO

in the formula, v_leo ^GEORepresenting the residual error of the observation equation of the low-orbit satellite to the high-orbit satellite; g^GEO() Represents X_HEOAnd obs_leo ^GEOThe functional relationship of (a); obs_leo ^GEoThe method comprises the steps that observation data of a low-orbit satellite to a high-orbit satellite are represented, wherein the observation data comprise pseudo-range observation data, carrier phase observation data and Doppler observation data; x_HEOThe dynamic parameters of the high orbit satellite are represented, and comprise an initial state vector of the high orbit satellite, an atmospheric resistance parameter, a light pressure parameter and an empirical force parameter; t is t_leoRepresenting the low earth orbit satellite observation epoch.

10) Using Taylor formula to make error equation be in initial value of parameter to be estimatedAnd (3) expanding the initial value to a first-order term, and simultaneously endowing corresponding prior constraints to the initial value:

in the formula, dX_HEORepresenting the number of corrections of the parameter to be estimated;

11) And then the least square estimation is used to obtain the estimation value of the parameter correction number to be estimatedWhile using the initial valuesRecovering to obtain the optimal estimated value of the parameter to be estimated;

12) after parameter estimation is completed, updating the initial state vector and the dynamic parameters of the high orbit satellite;

13) bringing an estimated value of a parameter to be estimated into an error equation, calculating a residual error, simultaneously carrying out search and inspection on the residual errors of all observation epochs, and re-marking cycle slip information and gross error information existing in the observed quantity;

14) repeating the steps 8 to 13 until the residual error is smaller than a set threshold value, and jumping out;

15) and generating a centimeter-level precision orbit position time sequence of the high-orbit satellite through orbit integration based on the initial state vector and the dynamic parameter information of the high-orbit satellite obtained by final estimation.