阅读说明：本技术 一种gnss双频用户终端导航定位授时精度提升方法 (GNSS dual-frequency user terminal navigation positioning time service precision improving method ) 是由 胡光明 刘源 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种GNSS双频用户终端导航定位授时精度提升方法,涉及定位技术领域,方法包括：根据GNSS卫星双频观测数据解算静态监测站的位置；对GNSS卫星观测数据,进行相位平滑伪距处理得到伪距观测量,根据伪距观测量和静态监测站的位置计算GNSS卫星伪距O-C序列,统计得到GNSS卫星的测量误差并发送给双频用户终端；使得双频用户终端可以在使用GNSS卫星的测量误差修正双频伪距观测量后,开展双频实时导航定位授时处理,获取用户终端的时空信息；本发明创新地提出在极少地面静态监测站支持下的精度增强服务改正信息计算方法,可实现定位精度的大幅提升,大大节约了地面建站成本,简化了增强服务的流程方法。(The invention discloses a GNSS dual-frequency user terminal navigation positioning time service precision improving method, which relates to the technical field of positioning and comprises the following steps: resolving the position of a static monitoring station according to the GNSS satellite dual-frequency observation data; performing phase smoothing pseudo-range processing on GNSS satellite observation data to obtain pseudo-range observation quantity, calculating a pseudo-range O-C sequence of the GNSS satellite according to the pseudo-range observation quantity and the position of a static monitoring station, counting to obtain a measurement error of the GNSS satellite, and sending the measurement error to a dual-frequency user terminal; the dual-frequency user terminal can carry out dual-frequency real-time navigation positioning time service processing after correcting dual-frequency pseudo-range observed quantity by using a measurement error of a GNSS satellite, and acquire time-space information of the user terminal; the invention innovatively provides a precision enhanced service correction information calculation method under the support of few ground static monitoring stations, which can greatly improve the positioning precision, greatly save the ground station building cost and simplify the service enhancement flow method.)

1. A GNSS dual-frequency user terminal navigation positioning time service precision improving method is characterized by comprising the following steps:

a1, resolving the position of a static monitoring station according to GNSS satellite dual-frequency observation data monitored by the static monitoring station;

a2, performing phase smoothing pseudo range processing on GNSS satellite observation data acquired by a static monitoring station to obtain pseudo range observed quantity after phase smoothing, calculating a pseudo range O-C sequence of the GNSS satellite according to the pseudo range observed quantity after phase smoothing and the position of the static monitoring station, and counting to obtain a dual-frequency pseudo range combined measurement error of the GNSS satellite;

step A3, sending the obtained double-frequency pseudo range combined measurement error of the GNSS satellite to a double-frequency user terminal; the method is used for correcting the navigation positioning time service algorithm by the double-frequency user terminal according to the double-frequency pseudo-range combined measurement error of the GNSS satellite.

2. The method according to claim 1, wherein the step a1 specifically includes:

step A1-1: reading GNSS pseudo-range and carrier phase observation data monitored by a static monitoring station for not less than 4 hours;

a1-2, performing data preprocessing on the read GNSS pseudo-range and carrier phase observation data and the satellite position and satellite clock error acquired based on the GNSS precise orbit and clock error products;

a1-3, performing gross error detection and cycle slip detection;

and A1-4, performing parameter estimation and calculating to obtain the position of the static monitoring station.

3. The method according to claim 2, wherein the step a1-4 specifically includes:

step A1-4-1: obtaining a receiver clock error, a troposphere delay parameter and an ionosphere delay parameter by adopting a least square or Kalman filtering estimation method, obtaining carrier phase floating ambiguity of all GNSS satellites, and obtaining the carrier phase integer ambiguity of the GNSS satellites by adopting an LAMBDA method;

a1-4-2, calculating and outputting the position of the static monitoring station according to the GNSS pseudo-range of the ground static monitoring station, a carrier phase observation equation and a precise point positioning observation equation;

the ground static monitoring station GNSS pseudo-range and carrier phase observation equation is as follows:

subscripts r and i represent receiver and navigation signal frequency identifications respectively, and superscripts s and j represent GNSS system and satellite identifications respectively;andrespectively representing pseudoranges and carrier phase observations of the frequency of the ss system j satellites i observed by the static monitoring station,representing the geometric distance between the stationary monitoring station and the satellite j,and T^s,jRespectively representing the receiver clock offset and the satellite clock offset,represents a parameter representative of the tropospheric delay,representing the ionospheric delay parameter at the i frequency,the navigation signal wavelength representing the frequency of the s-system i,representing the carrier phase integer ambiguity,andmeasurement noise representing pseudo range and carrier phase respectively;

the precise single-point positioning observation equation is as follows:

X^s,j(t_r) For the satellite of system j at signal transmission time t_rPosition of (A), X_rIs the location of the static monitoring station.

4. The method according to claim 1, wherein the step a2 specifically includes:

step A2-1, performing smooth filtering processing on pseudo-range observation values by utilizing carrier phase data on GNSS satellite observation data which are acquired by a static monitoring station and are not less than 24 hours, wherein the processing formula is as follows:

andare each t_k-1And t_kPseudorange observations at time after phase smoothing,andare each t_k-1And t_kThe carrier phase observed quantity at a moment, omega is a weight;

a2-2, calculating a visible GNSS satellite pseudo range O-C sequence according to the pseudo range observed quantity after the phase smoothing filtering processing and the position of a static monitoring station, and counting to obtain the double-frequency pseudo range combined measurement error of the GNSS satellite;

the method comprises the following steps:

the calculation method comprises the following steps:

subscripts r and i represent receiver and navigation signal frequency identifications respectively, and superscripts s and j represent GNSS system and satellite identifications respectively;for the pseudorange observations after the phase smoothing filtering process,as pseudo-range O-C value, X, of GNSS satellite_rThe position of the static monitoring station, delta t is the clock error between the satellite and the user terminal, and delta rho_sysIs a systematic error;

pseudo range O-C sequence based on GNSS satellite and adopting formulaCalculating a double-frequency combined O-C sequence corresponding to each GNSS satellite;

andrespectively obtaining double-frequency pseudo range O-C values of the ground static monitoring stations corresponding to the GNSS satellites; f. of₁And f₂Respectively the dual-frequency frequencies of the GNSS satellites,

based on the double-frequency combined O-C sequence corresponding to each GNSS satellite, adopting a formula

Calculating the double-frequency combined measurement error of each GNSS satellite;

Bias^s,jthe dual frequency pseudoranges for the s-system j-star combine the measurement error,and m is the number of the static monitoring stations for comprehensively evaluating the factors.

5. The method of claim 4, wherein before performing the smoothing filtering process on the pseudorange observation value using the carrier phase data, the method further comprises: and checking whether the observation data of the GNSS satellite is abnormal or not, performing cycle slip detection after checking that the observation data of the GNSS satellite is not abnormal, and then performing smooth filtering processing on the pseudo-range observation value by utilizing the carrier phase data.

6. The method according to claim 1, wherein the obtained dual-frequency pseudo-range combined measurement error of the GNSS satellite is sent to the dual-frequency user terminal, specifically: and broadcasting the obtained double-frequency pseudo range combined measurement error of the GNSS satellite to a double-frequency user terminal through one or more of a network, a satellite, a broadcast and a 5G mode.

7. The method according to claim 1, wherein the algorithm for correcting the navigation positioning time service by the dual-frequency user terminal according to the dual-frequency pseudo-range combined measurement error of the selected GNSS satellite specifically comprises:

step s 1: the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the GNSS satellite through a module for receiving satellite measurement error information in real time, decodes the dual-frequency pseudo-range combined measurement error of the GNSS satellite and obtains the dual-frequency pseudo-range combined measurement error of the GNSS satellite;

step s 2: by adopting an embedded algorithm, when a dual-frequency user carries out real-time navigation positioning time service resolving, the error is measured by using the dual-frequency pseudo range combination of the GNSS satellite, and the formula is used

Correcting the dual-frequency pseudo range observed quantity of the dual-frequency user terminal, using the corrected dual-frequency pseudo range observed quantity to carry out dual-frequency real-time navigation positioning time service processing, and acquiring the time-space information of the user terminal;

andthe pseudo-range observed quantity of the double frequency observed by the double frequency user terminal is obtained; bias^s,jThe dual frequency pseudoranges for the s-system j-star combine the measurement error,the corrected dual-frequency pseudo range observed quantity is obtained; f. of₁And f₂Respectively, the dual-frequency frequencies of the GNSS satellites.

8. A GNSS dual-frequency user terminal navigation positioning time service precision improving method is characterized by comprising the following steps:

step M1, the dual-frequency user terminal receives the dual-frequency pseudo range combined measurement error of the GNSS satellite;

and M2, the dual-frequency user terminal corrects the navigation positioning time service algorithm according to the dual-frequency pseudo-range combined measurement error of the GNSS satellite.

9. The method according to claim 8, wherein the step M1 specifically comprises:

the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the selected visible GNSS satellite through one or more of a network mode, a satellite mode, a broadcast mode and a 5G mode through a module for receiving satellite measurement error information in real time.

10. The method according to claim 8, comprising:

the M1 is specifically as follows: the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the GNSS satellite through a module for receiving satellite measurement error information in real time, decodes the dual-frequency pseudo-range combined measurement error of the GNSS satellite and obtains the dual-frequency pseudo-range combined measurement error of the GNSS satellite;

the M2 is specifically as follows: the dual-frequency user terminal adopts an embedded algorithm, and when the dual-frequency user carries out real-time navigation positioning time service resolving, the error is measured by using the dual-frequency pseudo range combination of the GNSS satellite, and the formula is used

Correcting the dual-frequency pseudo range observed quantity of the dual-frequency user terminal, using the corrected dual-frequency pseudo range observed quantity to carry out dual-frequency real-time navigation positioning time service processing, and acquiring the time-space information of the user terminal;

andthe pseudo-range observed quantity of the double frequency observed by the double frequency user terminal is obtained; bias^s,jThe dual frequency pseudoranges for the s-system j-star combine the measurement error,for modified dual-frequency pseudorange observations, f₁And f₂Respectively, the dual-frequency frequencies of the GNSS satellites.

Technical Field

The invention relates to the technical field of positioning, in particular to a GNSS dual-frequency user terminal navigation positioning time service precision improving method.

Background

With the economic development and the upgrading of industrial structures, the national social development and the economic activities of people require higher and higher spatio-temporal information. As an important space-time infrastructure, GNSS (Global Navigation Satellite System) plays an increasingly important role in the development of national society and the economic activity of people. Under the influence of ionosphere delay, the navigation positioning time service precision of the single-frequency user terminal cannot meet the requirement of higher-precision space-time information of economic activities of people, and the double-frequency user terminal gradually occupies larger and larger market components. However, due to the diversity of manufacturing processes and parameter selection, the dual-frequency user terminal faces the pseudo range error which is seriously amplified, and the navigation positioning time service precision has no significant advantage compared with a single-frequency user terminal.

However, the dual-frequency navigation positioning time service resolving of the user can obviously amplify the influence of pseudo-range measurement errors. With the continuous improvement of the satellite navigation system, the spatial signal precision of the navigation satellite is continuously improved, and is no longer a main bottleneck for improving the positioning precision of a dual-frequency user. The bottleneck effect of the pseudo-range measurement error on the dual-frequency navigation positioning time service precision is more obvious. The invention provides a method for improving the navigation positioning time service precision of a GNSS (global navigation satellite system) dual-frequency user terminal.

Disclosure of Invention

The GNSS dual-frequency user terminal navigation positioning time service precision improving method provided by the invention solves the problems.

The invention provides a GNSS dual-frequency user terminal navigation positioning time service precision improving method, which comprises the following steps:

a1, resolving the position of a static monitoring station according to GNSS satellite dual-frequency observation data monitored by the static monitoring station;

a2, performing phase smoothing pseudo range processing on GNSS satellite observation data acquired by a static monitoring station to obtain pseudo range observed quantity after phase smoothing, calculating a pseudo range O-C sequence of the GNSS satellite according to the pseudo range observed quantity after phase smoothing and the position of the static monitoring station, and counting to obtain a dual-frequency pseudo range combined measurement error of the GNSS satellite;

step A3, sending the obtained double-frequency pseudo range combined measurement error of the GNSS satellite to a double-frequency user terminal; the method is used for correcting the navigation positioning time service algorithm by the double-frequency user terminal according to the double-frequency pseudo-range combined measurement error of the GNSS satellite.

Optionally, the step a1 specifically includes:

step A1-1: reading GNSS pseudo-range and carrier phase observation data monitored by a static monitoring station for not less than 4 hours;

a1-2, performing data preprocessing on the read GNSS pseudo-range and carrier phase observation data and the satellite position and satellite clock error acquired based on the GNSS precise orbit and clock error products;

a1-3, performing gross error detection and cycle slip detection;

and A1-4, performing parameter estimation and calculating to obtain the position of the static monitoring station.

Optionally, the step a1-4 specifically includes:

step A1-4-1: obtaining a receiver clock error, a troposphere delay parameter and an ionosphere delay parameter by adopting a least square or Kalman filtering estimation method, obtaining carrier phase floating ambiguity of all GNSS satellites, and obtaining the carrier phase integer ambiguity of the GNSS satellites by adopting an LAMBDA method;

a1-4-2, calculating and outputting the position of the static monitoring station according to the GNSS pseudo-range of the ground static monitoring station, a carrier phase observation equation and a precise point positioning observation equation;

the ground static monitoring station GNSS pseudo-range and carrier phase observation equation is as follows:

the indices r and i represent the receiver and navigation signal frequency identifications, respectively, the indices s and jRespectively representing a GNSS system and a satellite identifier;andrespectively representing pseudoranges and carrier phase observations of the frequency of the ss system j satellites i observed by the static monitoring station,representing the geometric distance between the stationary monitoring station and the satellite j,and T^s,jRespectively representing the receiver clock offset and the satellite clock offset,represents a parameter representative of the tropospheric delay,representing the ionospheric delay parameter at the i frequency,the navigation signal wavelength representing the frequency of the s-system i,representing the carrier phase integer ambiguity,andmeasurement noise representing pseudo range and carrier phase respectively;

the precise single-point positioning observation equation is as follows:

X^s,j(t_r) For the satellite of system j at signal transmission time t_rPosition of (A), X_rIs the location of the static monitoring station.

Optionally, the step a2 specifically includes:

step A2-1, performing smooth filtering processing on pseudo-range observation values by utilizing carrier phase data on GNSS satellite observation data which are acquired by a static monitoring station and are not less than 24 hours, wherein the processing formula is as follows:

andare each t_k-1And t_kPseudorange observations at time after phase smoothing,andare each t_k-1And t_kThe carrier phase observed quantity at a moment, omega is a weight;

a2-2, calculating a visible GNSS satellite pseudo range O-C sequence according to the pseudo range observed quantity after the phase smoothing filtering processing and the position of a static monitoring station, and counting to obtain the double-frequency pseudo range combined measurement error of the GNSS satellite;

the method comprises the following steps:

the calculation method comprises the following steps:

subscripts r and i represent receiver and navigation signal frequency identifications respectively, and superscripts s and j represent GNSS system and satellite identifications respectively;for the pseudorange observations after the phase smoothing filtering process,as pseudo-range O-C value, X, of GNSS satellite_rThe position of the static monitoring station, delta t is the clock error between the satellite and the user terminal, and delta rho_sysIs a systematic error;

pseudo range O-C sequence based on GNSS satellite and adopting formulaCalculating a double-frequency combined O-C sequence corresponding to each GNSS satellite;

andrespectively obtaining double-frequency pseudo range O-C values of the ground static monitoring stations corresponding to the GNSS satellites; f. of₁And f₂Respectively the dual-frequency frequencies of the GNSS satellites,

based on the double-frequency combined O-C sequence corresponding to each GNSS satellite, adopting a formula

Calculating the double-frequency combined measurement error of each GNSS satellite;

Bias^s,jthe dual frequency pseudoranges for the s-system j-star combine the measurement error,and m is the number of the static monitoring stations for comprehensively evaluating the factors.

Optionally, before the performing smoothing filtering processing on the pseudo-range observation value by using the carrier-phase data, the method further includes: and checking whether the observation data of the GNSS satellite is abnormal or not, performing cycle slip detection after checking that the observation data of the GNSS satellite is not abnormal, and then performing smooth filtering processing on the pseudo-range observation value by utilizing the carrier phase data.

Optionally, the sending the obtained dual-frequency pseudo-range combined measurement error of the GNSS satellite to the dual-frequency user terminal specifically includes: and broadcasting the obtained double-frequency pseudo range combined measurement error of the GNSS satellite to a double-frequency user terminal through one or more of a network, a satellite, a broadcast and a 5G mode.

Optionally, the method for correcting the navigation positioning time service by the dual-frequency user terminal according to the dual-frequency pseudo-range combined measurement error of the selected GNSS satellite specifically includes:

step s 1: the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the GNSS satellite through a module for receiving satellite measurement error information in real time, decodes the dual-frequency pseudo-range combined measurement error of the GNSS satellite and obtains the dual-frequency pseudo-range combined measurement error of the GNSS satellite;

step s 2: by adopting an embedded algorithm, when a dual-frequency user carries out real-time navigation positioning time service resolving, the error is measured by using the dual-frequency pseudo range combination of the GNSS satellite, and the formula is used

Correcting the dual-frequency pseudo range observed quantity of the dual-frequency user terminal, using the corrected dual-frequency pseudo range observed quantity to carry out dual-frequency real-time navigation positioning time service processing, and acquiring the time-space information of the user terminal;

andthe pseudo-range observed quantity of the double frequency observed by the double frequency user terminal is obtained; bias^s,jThe dual frequency pseudoranges for the s-system j-star combine the measurement error,the corrected dual-frequency pseudo range observed quantity is obtained; f. of₁And f₂Respectively, the dual-frequency frequencies of the GNSS satellites.

The invention also provides a GNSS dual-frequency user terminal navigation positioning time service precision improving method, which comprises the following steps:

step M1, the dual-frequency user terminal receives the dual-frequency pseudo range combined measurement error of the GNSS satellite;

and M2, the dual-frequency user terminal corrects the navigation positioning time service algorithm according to the dual-frequency pseudo-range combined measurement error of the GNSS satellite.

Optionally, the step M1 is specifically:

the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the selected visible GNSS satellite through one or more of a network mode, a satellite mode, a broadcast mode and a 5G mode through a module for receiving satellite measurement error information in real time.

Optionally, comprising:

the M1 is specifically as follows: the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the GNSS satellite through a module for receiving satellite measurement error information in real time, decodes the dual-frequency pseudo-range combined measurement error of the GNSS satellite and obtains the dual-frequency pseudo-range combined measurement error of the GNSS satellite;

the M2 is specifically as follows: the dual-frequency user terminal adopts an embedded algorithm, and when the dual-frequency user carries out real-time navigation positioning time service resolving, the error is measured by using the dual-frequency pseudo range combination of the GNSS satellite, and the formula is used

Correcting the dual-frequency pseudo range observed quantity of the dual-frequency user terminal, using the corrected dual-frequency pseudo range observed quantity to carry out dual-frequency real-time navigation positioning time service processing, and acquiring the time-space information of the user terminal;

andthe pseudo-range observed quantity of the double frequency observed by the double frequency user terminal is obtained; bias^s,jThe dual frequency pseudoranges for the s-system j-star combine the measurement error,for modified dual-frequency pseudorange observations, f₁And f₂Respectively, the dual-frequency frequencies of the GNSS satellites.

The invention has the beneficial effects that: according to the method for improving the navigation positioning time service precision of the GNSS dual-frequency user terminal, the dual-frequency user terminal can perform dual-frequency real-time navigation positioning time service processing after correcting dual-frequency pseudo range observed quantity by using the dual-frequency pseudo range combined measurement error of a GNSS satellite, and acquire the time-space information of the user terminal; the accuracy enhancement service correction information calculation method under the support of few ground static monitoring stations is innovatively provided, the positioning accuracy can be greatly improved, the ground station building cost is greatly saved, and the service enhancement flow method is simplified.

Drawings

Fig. 1 is a flowchart of a method for improving the navigation positioning time service precision of a GNSS dual-frequency user terminal according to embodiment 1 of the present invention;

fig. 2 is a flowchart illustrating a specific operation of step a1 in the method for improving the accuracy of GNSS dual-band user terminal navigation positioning time service according to embodiment 1 of the present invention;

fig. 3 is a schematic view of a GNSS satellite dual-frequency pseudo-range combined measurement error broadcast provided in embodiment 2 of the present invention;

fig. 4 is an original positioning error sequence diagram before a dual-frequency pseudo-range observation of a dual-frequency user terminal is corrected by a dual-frequency pseudo-range combined measurement error of the dual-frequency user terminal according to embodiment 2 of the present invention;

fig. 5 is a positioning error sequence diagram of a dual-frequency pseudorange observed quantity of a dual-frequency user terminal corrected by a dual-frequency pseudorange combination measurement error by the dual-frequency user terminal according to embodiment 2 of the present invention.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The embodiment of the present invention provides a method for improving the navigation positioning time service precision of a GNSS dual-frequency user terminal, as shown in fig. 1, including:

a1, resolving the position of a static monitoring station according to GNSS satellite dual-frequency observation data monitored by the static monitoring station;

a2, performing phase smoothing pseudo range processing on GNSS satellite observation data acquired by a static monitoring station to obtain pseudo range observed quantity after phase smoothing, calculating a pseudo range O-C (difference between observed value and calculated value) sequence of the GNSS satellite according to the pseudo range observed quantity after phase smoothing and the position of the static monitoring station, and counting to obtain a dual-frequency pseudo range combined measurement error of the GNSS satellite;

step A3, sending the obtained double-frequency pseudo range combined measurement error of the GNSS satellite to a double-frequency user terminal; the method is used for correcting the navigation positioning time service algorithm by the double-frequency user terminal according to the double-frequency pseudo-range combined measurement error of the GNSS satellite.

Optionally, as shown in fig. 2, step a1 specifically includes:

step A1-1: reading GNSS pseudo-range and carrier phase observation data monitored by a static monitoring station for not less than 4 hours;

a1-2, performing data preprocessing on the read GNSS pseudo-range and carrier phase observation data and the satellite position and satellite clock error acquired based on the GNSS precise orbit and clock error products;

a1-3, performing gross error detection and cycle slip detection;

and A1-4, performing parameter estimation and calculating to obtain the position of the static monitoring station.

Optionally, step a1-4 specifically includes:

step A1-4-1: obtaining a receiver clock error, a troposphere delay parameter and an ionosphere delay parameter by adopting a least square or Kalman filtering estimation method, obtaining carrier phase floating ambiguity of all GNSS satellites, and obtaining the carrier phase integer ambiguity of the GNSS satellites by adopting an LAMBDA method;

a1-4-2, calculating and outputting the position of the static monitoring station according to the GNSS pseudo-range of the ground static monitoring station, a carrier phase observation equation and a precise point positioning observation equation;

the ground static monitoring station GNSS pseudo-range and carrier phase observation equation is as follows:

subscripts r and i represent receiver and navigation signal frequency identifications respectively, and superscripts s and j represent GNSS system and satellite identifications respectively;andrespectively representing pseudoranges and carrier phase observations of the frequency of the ss system j satellites i observed by the static monitoring station,representing the geometric distance between the stationary monitoring station and the satellite j,and T^s,jRespectively representing the receiver clock offset and the satellite clock offset,represents a parameter representative of the tropospheric delay,representing the ionospheric delay parameter at the i frequency,the navigation signal wavelength representing the frequency of the s-system i,representing the carrier phase integer ambiguity,andmeasurement noise representing pseudo range and carrier phase respectively;

the precise single-point positioning observation equation is as follows:

X^s,j(t_r) For the satellite of system j at signal transmission time t_rPosition of (A), X_rIs the location of the static monitoring station.

Optionally, step a2 specifically includes:

step A2-1, performing smooth filtering processing on pseudo-range observation values by utilizing carrier phase data on GNSS satellite observation data which are acquired by a static monitoring station and are not less than 24 hours, wherein the processing formula is as follows:

andare each t_k-1And t_kPseudorange observations at time after phase smoothing,andare each t_k-1And t_kLoad of time of dayWave phase observations, ω is weight;

a2-2, calculating a visible GNSS satellite pseudo range O-C sequence according to the pseudo range observed quantity after the phase smoothing filtering processing and the position of a static monitoring station, and counting to obtain the double-frequency pseudo range combined measurement error of the GNSS satellite;

the method comprises the following steps:

the calculation method comprises the following steps:

subscripts r and i represent receiver and navigation signal frequency identifications respectively, and superscripts s and j represent GNSS system and satellite identifications respectively;for the pseudorange observations after the phase smoothing filtering process,as pseudo-range O-C value, X, of GNSS satellite_rThe position of the static monitoring station, delta t is the clock error between the satellite and the user terminal, and delta rho_sysIs a systematic error;

pseudo range O-C sequence based on GNSS satellite and adopting formula

Calculating a double-frequency combined O-C sequence corresponding to each GNSS satellite;

andrespectively obtaining double-frequency pseudo range O-C values of the ground static monitoring stations corresponding to the GNSS satellites; f. of₁And f₂Respectively the dual-frequency frequencies of the GNSS satellites,

based on the double-frequency combined O-C sequence corresponding to each GNSS satellite, adopting a formula

Calculating the double-frequency combined measurement error of each GNSS satellite;

Bias^s,jthe dual frequency pseudoranges for the s-system j-star combine the measurement error,and m is the number of the static monitoring stations for comprehensively evaluating the factors.

Optionally, before performing a smoothing filtering process on the pseudorange observations using the carrier-phase data, the method further includes: and checking whether the observation data of the GNSS satellite is abnormal or not, performing cycle slip detection after checking that the observation data of the GNSS satellite is not abnormal, and then performing smooth filtering processing on the pseudo-range observation value by utilizing the carrier phase data.

Optionally, the obtained dual-frequency pseudo-range combined measurement error of the selected visible GNSS satellite is sent to a dual-frequency user terminal, specifically: and broadcasting the obtained double-frequency pseudo range combined measurement error of the GNSS satellite to a double-frequency user terminal through one or more of a network, a satellite, a broadcast and a 5G mode.

Optionally, the algorithm for correcting the navigation positioning time service by the dual-frequency user terminal according to the dual-frequency pseudo-range combined measurement error of the selected GNSS satellite specifically includes:

step s 1: the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the GNSS satellite through a module for receiving satellite measurement error information in real time, decodes the dual-frequency pseudo-range combined measurement error of the GNSS satellite and obtains the dual-frequency pseudo-range combined measurement error of the GNSS satellite;

step s 2: by adopting an embedded algorithm, when a dual-frequency user carries out real-time navigation positioning time service resolving, the error is measured by using the dual-frequency pseudo range combination of the GNSS satellite, and the formula is used

Correcting the dual-frequency pseudo range observed quantity of the dual-frequency user terminal, using the corrected dual-frequency pseudo range observed quantity to carry out dual-frequency real-time navigation positioning time service processing, and acquiring the time-space information of the user terminal;

andthe pseudo-range observed quantity of the double frequency observed by the double frequency user terminal is obtained; bias^s,jThe dual frequency pseudoranges for the s-system j-star combine the measurement error,for modified dual-frequency pseudorange observations

The invention also provides a GNSS dual-frequency user terminal navigation positioning time service precision improving method, which comprises the following steps:

step M1, the dual-frequency user terminal receives the dual-frequency pseudo range combined measurement error of the GNSS satellite;

and M2, the dual-frequency user terminal corrects the navigation positioning time service algorithm according to the dual-frequency pseudo-range combined measurement error of the GNSS satellite.

Optionally, step M1 is specifically:

the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the selected visible GNSS satellite through one or more of a network mode, a satellite mode, a broadcast mode and a 5G mode through a module for receiving satellite measurement error information in real time.

Optionally, comprising:

m1 specifically is: the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the GNSS satellite through a module for receiving satellite measurement error information in real time, decodes the dual-frequency pseudo-range combined measurement error of the GNSS satellite and obtains the dual-frequency pseudo-range combined measurement error of the GNSS satellite;

m2 specifically is: the dual-frequency user terminal adopts an embedded algorithm, and when the dual-frequency user carries out real-time navigation positioning time service resolving, the error is measured by using the dual-frequency pseudo range combination of the GNSS satellite, and the formula is used

Correcting the dual-frequency pseudo range observed quantity of the dual-frequency user terminal, using the corrected dual-frequency pseudo range observed quantity to carry out dual-frequency real-time navigation positioning time service processing, and acquiring the time-space information of the user terminal;

andthe pseudo-range observed quantity of the double frequency observed by the double frequency user terminal is obtained; bias^s,jThe dual frequency pseudoranges for the s-system j-star combine the measurement error,for modified dual-frequency pseudorange observations, f₁And f₂Respectively, the dual-frequency frequencies of the GNSS satellites.

According to the GNSS dual-frequency user terminal navigation positioning time service precision improving method provided by the embodiment, the dual-frequency user terminal can perform dual-frequency real-time navigation positioning time service processing after correcting dual-frequency pseudo-range observed quantity by using dual-frequency pseudo-range combined measurement errors of GNSS satellites, and acquire time-space information of the user terminal; the accuracy enhancement service correction information calculation method under the support of few ground static monitoring stations is innovatively provided, the positioning accuracy can be greatly improved, the ground station building cost is greatly saved, and the service enhancement flow method is simplified.

Example 2

The embodiment provides a method for improving the navigation positioning time service precision of a GNSS dual-frequency user terminal, aiming at the key bottleneck of improving the navigation positioning time service precision of the GNSS dual-frequency user terminal. The method is realized by the following steps:

step (1): under the support of centimeter-level GNSS Satellite precise orbits and precise clock error products, the position of a static monitoring station is solved by utilizing GNSS Satellite dual-frequency observation data monitored by a ground static monitoring station for not less than 4 hours, and the GNSS selectable in the step can comprise any one of a GPS (Global Positioning System), a GLONASS (Global NAvigation Satellite System), a GALILEO (Galileo Satellite NAvigation System), a QZSS (Quasi-Zenith Satellite System ) and a Beidou System or any multi-System combination;

step (2): performing phase smoothing pseudo range processing on the GNSS satellite observation data which is received by the static monitoring station in the step (1) and the monitoring receiver which is configured by the static monitoring station and the dual-frequency user terminal in the same way and is not less than 24 hours, calculating a visible GNSS satellite pseudo range O-C (difference between an observed value and a calculated value) sequence, and counting to obtain a dual-frequency pseudo range combined measurement error of the selected visible GNSS satellite, wherein the GNSS selectable in the step can comprise any one of a GPS system, a GLONASS system, a GALILEO system, a QZSS system and a Beidou system or any multi-system combination;

and (3): broadcasting the double-frequency pseudo-range combined measurement error of the selected visible GNSS satellite in the step (2) to a double-frequency user terminal through one or more of the modes of network, satellite, broadcast, 5G and the like;

and (4): and (4) the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the selected visual GNSS satellite broadcasted in the step (3), corrects the dual-frequency pseudo-range combined measurement error of the selected visual GNSS satellite to a navigation positioning time service algorithm, and is used for real-time navigation positioning time service resolving of the dual-frequency user terminal.

According to the invention, through the acquisition of the GNSS pseudo-range measurement error in the step (2) and the embedded navigation positioning time service method of the dual-frequency user terminal in the step (4), a precision enhanced service correction information calculation method under the support of few ground stations is innovatively provided, and the application cost of an enhanced service center and a user segment is greatly reduced.

Wherein, the specific mode of the step (1) is as follows:

(101) the ground static monitoring station GNSS pseudo range and carrier phase observation equation is as follows:

in the formula, subscripts r and i represent receiver and navigation signal frequency identifiers, respectively, and superscripts s and j represent GNSS system and satellite identifiers, respectively.Andrespectively representing pseudoranges and carrier phase observations of the frequency of the ss system j satellites i observed by the static monitoring station,representing the geometric distance between the stationary monitoring station and the satellite j,and T^s,jRespectively representing the receiver clock offset and the satellite clock offset,represents a parameter representative of the tropospheric delay,representing the ionospheric delay parameter at the i frequency,the navigation signal wavelength representing the frequency of the s-system i,representing the carrier phase integer ambiguity,andrepresenting the measured noise of the pseudorange and carrier phase, respectively. Wherein, the geometric distance between the satellite and the receiver in the precise point positioning observation equation can be expressed as

In the formula, X^s,j(t_r) For the satellite of system j at signal transmission time t_rPosition of (A), X_rIs the location of the static monitoring station.

(102) The position calculating method of the static monitoring station based on the precise single-point positioning observation equation comprises the following steps:

known quantities available based on GNSS precision orbit and clock error products include satellite position X^s,j(t_r) And satellite clock error T^s,j. Thus, the parameter to be estimated of the above equation includes the position X of the static monitoring station_rClock error of receiverTropospheric delay parameterIonospheric delay parameterAnd carrier phase integer ambiguityIf the GLONASS system is selected, the inter-frequency bias IFB parameter estimation needs to be considered. If a multi-GNSS system combined precise single-point positioning algorithm is adopted, the parameters of inter-system bias ISB and inter-frequency bias IFB are additionally estimated.

After reading the GNSS pseudo-range and carrier phase observation data, firstly, preprocessing the data, mainly comprising gross error detection and cycle slip detection, and then estimating parameters. In the parameter estimation process, a least square or Kalman filtering estimation method can be adopted to obtain the carrier phase floating ambiguity of all satellites, and then the integer ambiguity fixed solution of each satellite is obtained by adopting methods such as LAMBDA (least squares-based adaptive diversity acquisition) and the like, so that the position parameter X of the static monitoring station after the integer ambiguity fixed solution is obtained_r。

Wherein, the specific mode of the step (2) is as follows:

(201) for GNSS satellite observation data which are acquired by a ground static monitoring station and are not less than 24 hours, carrier phase data are utilized to carry out smooth filtering processing on pseudo-range observation values, and the method comprises the following steps:

in the formula (I), the compound is shown in the specification,andare each t_k-1And t_kPseudorange observations at time after phase smoothing,andare each t_k-1And t_kThe carrier phase observations at time, ω is a weight.

In step (201), before performing smoothing filtering processing on the pseudorange observation value by using the carrier phase data, the method may further include: and checking whether the observation data of the GNSS satellite is abnormal or not, performing cycle slip detection after checking that the observation data of the GNSS satellite is not abnormal, and performing smooth filtering processing on the pseudo-range observation value by utilizing carrier phase data.

(202) Calculating a pseudo range O-C sequence of a visible GNSS satellite based on the position of the ground static monitoring station calculated in the step (1) and the pseudo range observed quantity after phase smoothing in the step (201), and counting to obtain a double-frequency pseudo range combined measurement error of the selected visible GNSS satellite, wherein the method comprises the following steps:

in the formula (I), the compound is shown in the specification,is the pseudorange O-C value of the GNSS satellite,for pseudorange observations, X, after phase smoothing filtering_rδ t is the clock error between the satellite and the dual-frequency user terminal, δ ρ is the precise position coordinate of the ground monitoring station calculated based on the step (1)_sysThe system errors include ionosphere, troposphere, and multipath errors. Based on the pseudo-range O-C sequence of the GNSS satellite, the double-frequency combined O-C sequence corresponding to each GNSS satellite is calculated by adopting the following formula.

In the formula (f)₁And f₂Respectively the dual-frequency frequencies of the satellites of the GNSS system,andand respectively obtaining the double-frequency pseudo range O-C values of the ground static monitoring station corresponding to each GNSS system satellite. Based on the double-frequency combined O-C sequence of each GNSS satellite corresponding to a plurality of ground static monitoring stations, the following formula is adopted to calculate the double-frequency combined measurement error of each GNSS system.

In the formula, Bias^s,jThe dual frequency pseudoranges for the s-system j-star combine the measurement error,and m is the number of the ground static monitoring stations for comprehensively evaluating the factors.

Wherein, the specific mode of the step (3) is as follows:

after the pseudo-range dual-frequency combined measurement errors of the satellites of the GNSS systems calculated in step (2) are formatted according to a certain format, the pseudo-range dual-frequency combined measurement errors are broadcast to the dual-frequency user terminal 3 in real time based on one or more of modes such as 5G and broadcasting through a ground network processing center 1 or a satellite 2 and the like as shown in fig. 3.

And (4) any propagation mode of the double-frequency pseudo range combined measurement error of the GNSS satellite in the step (3) is within a protection range, and the propagation mode comprises but is not limited to oral transmission, telephone notification, Internet communication, satellite communication and the like.

Wherein, the specific mode of the step (4) is as follows:

and (3) the dual-frequency user terminal receives the dual-frequency pseudo-range combined measurement error of the selected GNSS satellite broadcasted in the step (3), corrects the dual-frequency pseudo-range combined measurement error of the selected GNSS satellite to a navigation positioning time service algorithm, and is used for real-time navigation positioning time service resolving of the dual-frequency user terminal, wherein the method comprises the following steps:

(401) adding a module for receiving satellite measurement error information in real time on a universal standardized double-frequency user terminal, decoding a received double-frequency pseudo-range combined measurement error in a specific format, and acquiring an error correction value Bias of each GNSS satellite^{s ,j}。

(402) The dual-frequency user terminal adopts a new embedded algorithm, when the dual-frequency user carries out real-time navigation positioning time service resolving, the dual-frequency pseudo range observed quantity of the dual-frequency user terminal is corrected by utilizing the dual-frequency pseudo range combined measurement error of each GNSS satellite decoded by the terminal, and the new dual-frequency pseudo range observed quantity is usedAnd carrying out double-frequency real-time navigation positioning time service processing to obtain the time-space information of the user terminal.

In the formula (f)₁And f₂Respectively the dual-frequency frequencies of the satellites of the GNSS system,andand (4) obtaining the dual-frequency pseudo range observed quantity for the dual-frequency user terminal.

Fig. 4 is an original positioning error sequence diagram before a dual-frequency pseudo-range observation of a dual-frequency user terminal is corrected by a dual-frequency pseudo-range combined measurement error, which is not used by the dual-frequency user terminal; fig. 5 is a positioning error sequence diagram after a dual-frequency pseudorange combination measurement error is used by a dual-frequency subscriber terminal to correct a dual-frequency pseudorange observed quantity of the dual-frequency subscriber terminal.

Compared with a positioning method in the prior art that a foundation enhancement system needs to be provided with thousands of ground monitoring stations, the method can calculate the pseudo-range measurement error of the GNSS satellite only based on GNSS satellite dual-frequency observation data monitored by a very small number (such as a few or even only 1) of ground static monitoring stations, and the dual-frequency user terminal adopts a new embedded algorithm, so that the positioning accuracy can be greatly improved, the ground station construction cost is greatly saved, and the flow method for enhancing the service is simplified. The GNSS satellite dual-frequency pseudo-range combined measurement error content of the method is concise, the broadcasting frequency is low, the GNSS satellite dual-frequency pseudo-range combined measurement error content is broadcasted to a dual-frequency user terminal in real time based on one or more of the modes of 5G, broadcasting and the like by carriers such as a satellite or a ground network, the broadcasting cost is reduced, and the usability of the user enhanced service is greatly improved. In addition, the method aims at the general consumption level users, can provide precision enhancement service with extremely low cost, and has obvious application advantages and larger potential user population compared with the existing foundation enhancement system. Compared with the existing enhancement modes such as foundation and satellite-based, the communication frequency of the user terminal and the system end is reduced from second level to minute level to hours level to days level, the communication and data transmission frequency is greatly reduced, and the communication pressure is greatly reduced.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.