PPP-B2b satellite clock error correction value abnormal jump processing method and system

Abstract

The present application relates to a kind of PPP-B2b satellite clock error correction value abnormal jump processing method and system, method includes: when the GPS reference satellite of current epoch and previous epoch is switched, reference variation is obtained, clock error correction value is corrected;Clock error correction value of GPS satellite and BDS-3 satellite is superimposed to broadcast ephemeris, and precise satellite clock error is recovered;The difference value of each satellite's precise satellite clock error is calculated;When the difference value of the precise satellite clock error of target satellite is greater than preset threshold, it is determined that there is abnormal jump;It is not reference satellite, then initialize clock error abnormal processing parameter in the positioning observation equation of target satellite;It is reference satellite, then initialize clock error abnormal processing parameter in the positioning observation equation of all satellites of current epoch;So absorb the abnormal jump part of clock error correction value.Avoid real-time PPP positioning result jump caused by clock error abnormal value, improve the continuity and reliability of PPP-B2b precise positioning result.

Description

Technical Field

[0001] This invention relates to the field of satellite navigation and positioning technology, and in particular to a method and system for handling abnormal jumps in PPP-B2b satellite clock error correction values. Background Technology

[0002] The correction products broadcast by China's BeiDou-3 Navigation Satellite System (BDS-3) include precise satellite orbits, precise clock biases, and inter-code offsets. Compared to the traditional real-time PPP technology that relies on the internet to obtain correction data, PPP-B2b only needs to receive PPP-B2b correction values ​​broadcast by GEO satellites to achieve real-time dynamic positioning. It meets the requirement that the real-time PPP convergence time of the BDS-3 / GPS dual system is within 20 minutes, achieving centimeter-level horizontal positioning accuracy under static observation conditions and decimeter-level (10-20 cm) real-time positioning performance under dynamic scenarios. The emergence of BDS-3 PPP-B2b has constructed a new satellite-based augmentation real-time precise point positioning mode. By using the mechanism of satellite-broadcasted correction data, it eliminates dependence on terrestrial communication network environments and equipment, forming a precise positioning augmentation system that is heterogeneous and collaborative with ground-based augmentation systems. It can serve as an effective supplement to ground-based augmentation real-time precise positioning, providing another feasible alternative for the realization of real-time PPP.

[0003] However, in real-time precise point positioning using PPP-B2b GPS or BDS-3 systems, the satellite clock correction values ​​broadcast by GEO satellites exhibit random and unpredictable anomalous jumps. The direct consequence is that some satellite clock correction values ​​show excessive deviations (typically exceeding 3 ns). These anomalies originate from factors such as onboard atomic clock frequency drift, satellite-to-ground time synchronization errors, and transient interference in the correction data broadcasting link. These factors can disrupt the continuity of PPP-B2b satellite clock correction values, leading to sudden shifts in real-time positioning results (maximum horizontal shift exceeding 1 m) and filter re-convergence. Therefore, it is urgent to establish a real-time detection and processing method for random anomalous jumps in PPP-B2b satellite clock correction values, thereby ensuring continuous and stable real-time PPP calculations and avoiding sudden changes or even re-convergence in positioning caused by clock correction anomalies. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] Firstly, a method for handling anomalous jumps in PPP-B2b satellite clock error correction values ​​is provided, including:

[0006] Clock correction values ​​and broadcast ephemeris values ​​for GPS and BDS-3 satellites in PPP-B2b are collected through user receivers.

[0007] The clock error correction value of the GPS satellite is used to determine whether the GPS reference satellite has switched between the current epoch and the previous epoch.

[0008] If the GPS reference satellites of the current epoch switch with those of the previous epoch, the reference change is calculated based on the clock error correction values ​​of the common GPS satellites of the current epoch and the previous epoch. The clock error correction values ​​of all visible GPS satellites of the current epoch are then corrected based on the reference change to obtain the corrected clock error correction values ​​of the GPS satellites.

[0009] The corrected clock bias values ​​of GPS satellites and BDS-3 satellites are superimposed on the broadcast ephemeris to calculate the satellite clock bias parameters. The precise satellite clock bias is then recovered based on the satellite clock bias parameters.

[0010] The precise satellite clock difference between the current epoch and the previous epoch is differentially processed to obtain the precise satellite clock difference difference value of each satellite; when the precise satellite clock difference difference value of the target satellite is greater than the preset threshold, it is determined that there is an abnormal jump in the clock difference correction value of the target satellite in the current epoch.

[0011] Determine whether the target satellite is a reference satellite;

[0012] If not, initialize the clock error handling parameters in the positioning observation equation of the target satellite to absorb the abnormal jump part of the clock error correction value;

[0013] If so, initialize the clock error handling parameters in the positioning observation equations of all satellites in the current epoch, thereby absorbing the abnormal jump portion of the clock error correction value.

[0014] Furthermore, broadcast ephemeris types are divided into GPS LNAV broadcast ephemeris and BDS-3 CNAV1 broadcast ephemeris.

[0015] Furthermore, determining whether the GPS reference satellites have switched between the current epoch and the previous epoch includes:

[0016] Obtain the clock correction values ​​for GPS satellites from the previous epoch;

[0017] Compare the clock correction values ​​of GPS satellites in the previous epoch with the clock correction values ​​of GPS satellites in the current epoch.

[0018] If only one target GPS satellite has a clock error correction value of 0 at the current epoch, then the target GPS satellite is used as the GPS reference satellite. It is then determined whether the GPS reference satellite at the current epoch is consistent with the GPS reference satellite at the previous epoch. If they are inconsistent, it is determined that a GPS reference satellite switch has occurred. If they are consistent, it is determined that no GPS reference satellite switch has occurred.

[0019] If the clock error correction values ​​of all GPS satellites in the current epoch are not 0, then the GPS reference satellite cannot be determined, and it is determined that no GPS reference satellite switch has occurred.

[0020] If the clock error correction value of multiple GPS satellites in the current epoch is 0, then the GPS reference satellite of the previous epoch is used as the GPS reference satellite of the current epoch, and it is determined that no GPS reference satellite switch has occurred.

[0021] Furthermore, the baseline change is calculated based on the clock bias correction values ​​of the common-view GPS satellites at the current epoch and the previous epoch. The clock bias correction values ​​of all visible GPS satellites at the current epoch are then corrected based on this baseline change to obtain the corrected clock bias correction values ​​for the GPS satellites, including:

[0022] The clock error correction values ​​of the common-view GPS satellites at the current epoch and the previous epoch are differentially processed to obtain the differential value of each common-view GPS satellite.

[0023] Calculate the average of the difference values ​​of all common-view GPS satellites to obtain the baseline change between the current epoch and the previous epoch;

[0024] The clock error correction values ​​of all visible GPS satellites at the current epoch are corrected using the baseline change, resulting in the corrected clock error correction values ​​for the GPS satellites.

[0025] Furthermore, the corrected clock bias values ​​of GPS satellites and BDS-3 satellites are superimposed on the broadcast ephemeris to calculate the satellite clock bias parameters. Based on these parameters, the precise satellite clock bias is recovered, including:

[0026] The satellite clock error parameters are calculated by superimposing the corrected clock errors of GPS satellites and BDS-3 satellites onto the broadcast ephemeris. ;

[0027] According to satellite clock bias parameters Precision satellite clock bias was recovered. The calculation formula is:

[0028] ;

[0029] in, Represents the speed of light under vacuum conditions; This indicates the preset clock error correction value, which is set according to the PPP-B2b correction product preset.

[0030] Furthermore, the corrected clock bias values ​​of GPS satellites and BDS-3 satellites are superimposed on the broadcast ephemeris to calculate the satellite clock bias parameters. After recovering the precise satellite clock bias based on these parameters, the process also includes:

[0031] To add a clock difference anomaly processing parameter to the positioning observation equations for pseudorange and carrier phase of each satellite at each frequency in PPP-B2b, the satellite with the highest elevation angle is selected as the reference satellite for subsequent epochs, and the value of the positioning observation equation of the reference satellite is set to 0 to eliminate the rank deficiency of the positioning observation equation.

[0032] The GPS / BDS-3 dual-system dual-frequency non-combined real-time PPP positioning model for PPP-B2b is represented as follows:

[0033] ;

[0034] ;

[0035] Where C represents BDS-3; G represents GPS; s represents satellite identifier; r represents user receiver; j represents satellite signal frequency; and These represent the pseudorange observations from BDS-3 and GPS satellites minus the calculated values, respectively. and These represent the carrier phase observations from BDS-3 satellites and GPS satellites minus the calculated values, respectively. and These represent the station-to-satellite line-of-sight unit vectors for BDS-3 and GPS satellites, respectively. This represents the three-dimensional position of the user receiver r; This represents the product of the speed of light and the receiver clock error estimated by the BDS-3 satellite. This represents the product of the speed of light and the receiver clock error estimated by GPS satellites. and It absorbs the pseudorange hardware delay of BDS-3 satellites and GPS satellites at the user receiver end, respectively; and These represent the tropospheric projection coefficients of the BDS-3 and GPS satellites, respectively. This indicates the wet delay in the tropospheric zenith direction at the user receiver end; and These represent the ionospheric conversion coefficients of the BDS-3 satellite and the GPS satellite, respectively. and These represent the estimated ionospheric delay on the tilted paths of the BDS-3 and GPS satellites at the first frequency, respectively. It only absorbs the pseudorange hardware delay at the user receiver end. It absorbs the pseudorange hardware delay at the user receiver end, and also absorbs the uncorrected pseudorange hardware delay at the GPS satellite end; and represents the BDS-3 satellite and GPS satellite respectively; and The j-th frequency of the BDS-3 satellite and the GPS satellite respectively absorbs the pseudorange hardware delay and phase hardware delay at the satellite end, and also absorbs the ambiguity estimate of the pseudorange hardware delay and phase hardware delay at the user receiver end. and These represent the clock anomaly handling parameters added to the positioning observation equations for BDS-3 and GPS satellites, respectively.

[0036] Furthermore, the satellite clock bias of PPP-B2b exhibits a relatively stable characteristic within each continuous arc, and the clock bias anomaly handling parameters are set as a random walk process.

[0037] Secondly, a PPP-B2b satellite clock error correction anomaly jump handling system is provided, including:

[0038] The data acquisition module is used to acquire clock correction values ​​and broadcast ephemeris values ​​of GPS and BDS-3 satellites for PPP-B2b via a user receiver.

[0039] The GPS reference satellite switching determination module is used to determine whether a switch has occurred between the current epoch and the previous epoch based on the clock error correction value of the GPS satellite.

[0040] The GPS satellite clock correction module is used to calculate the reference change based on the clock correction values ​​of the common GPS satellites in the current epoch and the previous epoch if the GPS reference satellites switch between the current epoch and the previous epoch. The clock correction values ​​of all visible GPS satellites in the current epoch are then corrected based on the reference change to obtain the corrected clock correction value of the GPS satellites.

[0041] The satellite clock error recovery module is used to superimpose the corrected clock error values ​​of GPS satellites and BDS-3 satellites onto the broadcast ephemeris, calculate the satellite clock error parameters, and recover the precise satellite clock error based on the satellite clock error parameters.

[0042] The abnormal jump detection module is used to perform differential processing on the precision satellite clock difference between the current epoch and the previous epoch to obtain the precision satellite clock difference difference value of each satellite; when the precision satellite clock difference difference value of the target satellite is greater than the preset threshold, it is determined that there is an abnormal jump in the clock difference correction value of the target satellite in the current epoch.

[0043] The abnormal jump processing module is used to determine whether the target satellite is a reference satellite. If not, it initializes the clock difference anomaly processing parameters in the positioning observation equation of the target satellite to absorb the abnormal jump part of the clock difference correction value. If it is, it initializes the clock difference anomaly processing parameters in the positioning observation equation of all satellites in the current epoch to absorb the abnormal jump part of the clock difference correction value.

[0044] The beneficial effects achieved by this invention are as follows:

[0045] The clock correction values ​​and broadcast ephemeris of GPS and BDS-3 satellites in PPP-B2b are collected by the user receiver. Based on the GPS satellite clock correction values, it is determined whether the GPS reference satellite has switched between the current and previous epochs. If a switch has occurred, the reference change is calculated based on the clock correction values ​​of the common-view GPS satellites between the current and previous epochs. The clock correction values ​​of all visible GPS satellites in the current epoch are then corrected based on this reference change to obtain the corrected clock correction values ​​for the GPS satellites. The corrected clock correction values ​​of the GPS satellites and the BDS-3 satellites are then superimposed on the broadcast ephemeris to calculate the corrected clock correction values. The system retrieves satellite clock bias parameters and recovers precise satellite clock bias based on these parameters. It then performs differential processing on the precise satellite clock biases of the current epoch and the previous epoch to obtain the precise satellite clock bias difference value for each satellite. When the precise satellite clock bias difference value of the target satellite exceeds a preset threshold, it determines that there is an abnormal jump in the clock bias correction value of the target satellite in the current epoch. It then determines whether the target satellite is a reference satellite. If not, it initializes the clock bias anomaly processing parameters in the positioning observation equation of the target satellite to absorb the abnormal jump portion of the clock bias correction value. If so, it initializes the clock bias anomaly processing parameters in the positioning observation equations of all satellites in the current epoch to absorb the abnormal jump portion of the clock bias correction value. Addressing the random abnormal jump phenomenon in satellite clock bias correction values ​​in PPP-B2b, by recovering the precise clock bias of PPP-B2b and introducing clock bias anomaly processing parameters into the positioning equation, it can detect and process random abnormal jumps in clock bias in real time. This avoids jumps in real-time PPP positioning results caused by clock bias anomalies, improving the continuity and reliability of PPP-B2b real-time precise positioning results. Attached Figure Description

[0046] Figure 1 This is a flowchart of the PPP-B2b satellite clock error correction value abnormal jump handling method of the present invention;

[0047] Figure 2 This is a structural diagram of the PPP-B2b satellite clock error correction value abnormal jump processing system of the present invention. Detailed Implementation

[0048] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0049] like Figure 1 As shown, this embodiment of the invention provides a method for handling abnormal jumps in PPP-B2b satellite clock bias correction values, including:

[0050] 101. Collect clock correction values ​​and broadcast ephemeris values ​​of GPS satellites and BDS-3 satellites for PPP-B2b through user receivers;

[0051] The user receiver synchronously acquires GPS L1 / L2 and BDS-3 B1I / B3I observation data, and decodes two types of navigation messages in real time: LNAV (GPS navigation message) and CNAV1 (BDS-3 navigation message). Simultaneously, it receives high-precision satellite clock corrections, satellite orbit corrections, inter-frequency code deviation (DCB) corrections, and antenna phase center deviation (PCO / PCV) auxiliary enhancement data broadcast by BeiDou-3 geostationary orbit (GEO) satellites via PPP-B2b enhancement signals. The broadcast ephemeris types are GPS LNAV broadcast ephemeris and BDS-3 CNAV1 broadcast ephemeris.

[0052] 102. Determine whether the GPS reference satellite has switched between the current epoch and the previous epoch based on the clock error correction value of the GPS satellite.

[0053] Considering that the PPP-B2b GPS satellite clock reference changes frequently, the clock correction value of the GPS satellite in the previous epoch is dynamically stored, and compared with the clock correction value of the GPS satellite in the current epoch. The satellite with a clock correction of zero is selected as the GPS reference satellite.

[0054] If only one target GPS satellite has a clock error correction value of 0 at the current epoch, then the target GPS satellite is used as the GPS reference satellite. It is then determined whether the GPS reference satellite at the current epoch is consistent with the GPS reference satellite at the previous epoch. If they are inconsistent, it is determined that a GPS reference satellite switch has occurred, and subsequent step 103 is executed. If they are consistent, it is determined that no GPS reference satellite switch has occurred.

[0055] If the clock correction values ​​of all GPS satellites at the current epoch are not 0, it is considered that the clock correction value of that epoch is incorrect, the GPS reference satellite at the current epoch cannot be determined, it is determined that no GPS reference satellite switch has occurred, and the clock correction values ​​of all satellites are not included in the subsequent reference unification process.

[0056] If the clock error correction value of multiple GPS satellites in the current epoch is 0, then the GPS reference satellite of the previous epoch is used as the GPS reference satellite of the current epoch, and it is determined that no GPS reference satellite switch has occurred, thus realizing the reference consistency processing of observation data in multiple time periods.

[0057] 103. The reference change is calculated based on the clock error correction values ​​of the common GPS satellites at the current epoch and the previous epoch. The clock error correction values ​​of all visible GPS satellites at the current epoch are then corrected based on the reference change to obtain the corrected clock error correction values ​​of the GPS satellites.

[0058] When the GPS reference satellites switch between adjacent epochs, a reference consistency correction model needs to be constructed based on the clock bias correction values ​​of the common-view GPS satellites, specifically:

[0059] The clock error correction values ​​of the common-view GPS satellites at the current epoch and the previous epoch are differentially processed to obtain the differential value of each common-view GPS satellite.

[0060] Calculate the average of the difference values ​​of all common-view GPS satellites to obtain the baseline change between the current epoch and the previous epoch;

[0061] The clock error correction values ​​of all visible GPS satellites at the current epoch are corrected using the baseline change, resulting in the corrected clock error correction values ​​for the GPS satellites.

[0062] To ensure the continuity of reference transmission, in scenarios involving multiple reference satellite switching, it is necessary to update the overall reference correction based on the historically accumulated reference offset and the differential mean of the current epoch. This will reduce the clock bias reference jump error caused by frequent changes in the reference satellite and obtain a sequence of stable GPS satellite clock bias correction values.

[0063] 104. The corrected clock bias values ​​of GPS satellites and BDS-3 satellites are superimposed on the broadcast ephemeris to calculate the satellite clock bias parameters. The precise satellite clock bias is then recovered based on the satellite clock bias parameters.

[0064] The satellite clock error parameters are calculated by superimposing the corrected clock errors of GPS satellites and BDS-3 satellites onto the broadcast ephemeris. ;

[0065] According to satellite clock bias parameters Precision satellite clock bias was recovered. The calculation formula is:

[0066] ;

[0067] in, Represents the speed of light under vacuum conditions; This indicates the preset clock error correction value, which is set according to the PPP-B2b correction product preset.

[0068] 105. Perform differential processing on the precision satellite clock difference between the current epoch and the previous epoch to obtain the precision satellite clock difference difference value of each satellite; when the precision satellite clock difference difference value of the target satellite is greater than the preset threshold, it is determined that there is an abnormal jump in the clock difference correction value of the target satellite in the current epoch.

[0069] Based on prior experience, a threshold is set. If the precision satellite clock error difference value of the clock error correction value of a certain satellite exceeds the preset threshold, it is considered that the clock error value of that satellite in the current epoch has an abnormal jump.

[0070] 106. Determine whether the target satellite is a reference satellite;

[0071] If the target satellite is not the reference satellite, proceed to step 107; if the target satellite is the reference satellite, proceed to step 108.

[0072] 107. Initialize the clock error handling parameters in the positioning observation equation of the target satellite to absorb the abnormal jump part of the clock error correction value;

[0073] The target satellite is not the reference satellite. The clock error handling parameters in the positioning observation equation of the target satellite are initialized. The satellite clock error of PPP-B2b exhibits a relatively stable characteristic in each continuous arc. The clock error handling parameters are set to a random walk process.

[0074] 108. Initialize the clock error handling parameters in the positioning observation equations of all satellites in the current epoch, thereby absorbing the abnormal jump part of the clock error correction value.

[0075] The target satellite is the reference satellite. The clock error handling parameters in the positioning observation equations of all satellites in the current epoch are initialized. The clock error handling parameters estimated based on the latest observation information can effectively absorb the abnormal jump part of the PPP-B2b satellite clock error correction value, ensuring the robustness between positioning filter estimation parameters and the continuity of positioning.

[0076] In the above Figure 1 In steps 107 and 108 of the illustrated embodiment, the satellite positioning observation equation and clock error handling parameters are pre-defined. Existing PPP-B2b GPS and BDS-3 system satellites have initial systematic biases. Since these initial systematic biases are absorbed by the phase ambiguity parameters during parameterization, and pseudorange observations directly reduce the accuracy of pseudorange during the positioning convergence phase, they do not affect the positioning accuracy after convergence, but they do reduce the accuracy of pseudorange observations and affect the early convergence time of positioning. Therefore, to compensate for this bias, the PPP-B2b real-time positioning model introduces an initial satellite clock error bias compensation parameter into the positioning observation equation of pseudorange for each satellite. However, random outliers in satellite clock errors are abnormal phenomena that affect not only pseudorange but also carrier phase observations. Therefore, it is proposed to add an abnormal clock error handling parameter to the positioning observation equations of pseudorange and carrier phase for each frequency of each satellite in PPP-B2b to absorb the influence of clock error outliers.

[0077] Preferably, in some embodiments of the present invention, after step 104, which involves superimposing the corrected clock bias values ​​of the GPS satellites and the BDS-3 satellites onto the broadcast ephemeris to calculate the satellite clock bias parameters, and then recovering the precise satellite clock bias based on the satellite clock bias parameters, the method further includes:

[0078] To add a clock difference anomaly processing parameter to the positioning observation equations for pseudorange and carrier phase of each satellite at each frequency in PPP-B2b, the satellite with the highest elevation angle is selected as the reference satellite for subsequent epochs, and the value of the positioning observation equation of the reference satellite is set to 0 to eliminate the rank deficiency of the positioning observation equation.

[0079] The GPS / BDS-3 dual-system dual-frequency non-combined real-time PPP positioning model for PPP-B2b is represented as follows:

[0080] ;

[0081] ;

[0082] Where C represents BDS-3; G represents GPS; s represents satellite identifier; r represents user receiver; j represents satellite signal frequency; and These represent the pseudorange observations from BDS-3 and GPS satellites minus the calculated values, respectively. and These represent the carrier phase observations from BDS-3 satellites and GPS satellites minus the calculated values, respectively. and These represent the station-to-satellite line-of-sight unit vectors for BDS-3 and GPS satellites, respectively. This represents the three-dimensional position of the user receiver r; This represents the product of the speed of light and the receiver clock error estimated by the BDS-3 satellite. This represents the product of the speed of light and the receiver clock error estimated by GPS satellites. and It absorbs the pseudorange hardware delay of BDS-3 satellites and GPS satellites at the user receiver end, respectively; and These represent the tropospheric projection coefficients of the BDS-3 and GPS satellites, respectively. This indicates the wet delay in the tropospheric zenith direction at the user receiver end; and These represent the ionospheric conversion coefficients of the BDS-3 satellite and the GPS satellite, respectively. and These represent the estimated ionospheric delay on the tilted paths of the BDS-3 and GPS satellites at the first frequency, respectively. It only absorbs the pseudorange hardware delay at the user receiver end. It absorbs the pseudorange hardware delay at the user receiver end, and also absorbs the uncorrected pseudorange hardware delay at the GPS satellite end; and represents the BDS-3 satellite and GPS satellite respectively; and The j-th frequency of the BDS-3 satellite and the GPS satellite respectively absorbs the pseudorange hardware delay and phase hardware delay at the satellite end, and also absorbs the ambiguity estimate of the pseudorange hardware delay and phase hardware delay at the user receiver end. and These represent the clock anomaly handling parameters added to the positioning observation equations for BDS-3 and GPS satellites, respectively.

[0083] The beneficial effects of the embodiment of the PPP-B2b satellite clock error correction anomaly jump handling method of the present invention are as follows:

[0084] The clock correction values ​​and broadcast ephemeris of GPS and BDS-3 satellites in PPP-B2b are collected by the user receiver. Based on the GPS satellite clock correction values, it is determined whether the GPS reference satellite has switched between the current and previous epochs. If a switch has occurred, the reference change is calculated based on the clock correction values ​​of the common-view GPS satellites between the current and previous epochs. The clock correction values ​​of all visible GPS satellites in the current epoch are then corrected based on this reference change to obtain the corrected clock correction values ​​for the GPS satellites. The corrected clock correction values ​​of the GPS satellites and the BDS-3 satellites are then superimposed on the broadcast ephemeris to calculate the corrected clock correction values. The system retrieves satellite clock bias parameters and recovers precise satellite clock bias based on these parameters. It then performs differential processing on the precise satellite clock biases of the current epoch and the previous epoch to obtain the precise satellite clock bias difference value for each satellite. When the precise satellite clock bias difference value of the target satellite exceeds a preset threshold, it determines that there is an abnormal jump in the clock bias correction value of the target satellite in the current epoch. It then determines whether the target satellite is a reference satellite. If not, it initializes the clock bias anomaly processing parameters in the positioning observation equation of the target satellite to absorb the abnormal jump portion of the clock bias correction value. If so, it initializes the clock bias anomaly processing parameters in the positioning observation equations of all satellites in the current epoch to absorb the abnormal jump portion of the clock bias correction value. Addressing the random abnormal jump phenomenon in satellite clock bias correction values ​​in PPP-B2b, by recovering the precise clock bias of PPP-B2b and introducing clock bias anomaly processing parameters into the positioning equation, it can detect and process random abnormal jumps in clock bias in real time. This avoids jumps in real-time PPP positioning results caused by clock bias anomalies, improving the continuity and reliability of PPP-B2b real-time precise positioning results.

[0085] Based on the PPP-B2b satellite clock error correction value abnormal jump handling method described in the above embodiments, the PPP-B2b satellite clock error correction value abnormal jump handling system will be explained below through embodiments.

[0086] like Figure 2 As shown, this embodiment of the invention provides a PPP-B2b satellite clock error correction anomaly jump handling system, including:

[0087] The data acquisition module 201 is used to acquire clock correction values ​​and broadcast ephemeris values ​​of GPS satellites and BDS-3 satellites of PPP-B2b through the user receiver;

[0088] GPS reference satellite switching determination module 202 is used to determine whether the GPS reference satellite of the current epoch has switched with the GPS reference satellite of the previous epoch based on the clock error correction value of the GPS satellite.

[0089] GPS satellite clock correction module 203 is used to calculate the reference change based on the clock correction value of the common GPS satellites in the current epoch and the previous epoch if the GPS reference satellite is switched between the current epoch and the previous epoch. Then, it corrects the clock correction value of all visible GPS satellites in the current epoch based on the reference change value to obtain the corrected clock correction value of the GPS satellite.

[0090] The satellite clock error recovery module 204 is used to superimpose the corrected clock error values ​​of GPS satellites and BDS-3 satellites onto the broadcast ephemeris, calculate the satellite clock error parameters, and recover the precise satellite clock error based on the satellite clock error parameters.

[0091] The abnormal jump detection module 205 is used to perform differential processing on the precision satellite clock difference between the current epoch and the previous epoch to obtain the precision satellite clock difference difference value of each satellite; when the precision satellite clock difference difference value of the target satellite is greater than a preset threshold, it is determined that there is an abnormal jump in the clock difference correction value of the target satellite in the current epoch.

[0092] The abnormal jump processing module 206 is used to determine whether the target satellite is a reference satellite; if not, it initializes the clock difference abnormal processing parameters in the positioning observation equation of the target satellite to absorb the abnormal jump part of the clock difference correction value; if so, it initializes the clock difference abnormal processing parameters in the positioning observation equation of all satellites in the current epoch to absorb the abnormal jump part of the clock difference correction value.

[0093] The beneficial effects of the embodiments of the present invention are as follows:

[0094] To address the issue of random anomalies in satellite clock correction values ​​in PPP-B2b, this paper proposes a method to recover the precise clock bias of PPP-B2b and introduce clock bias anomaly handling parameters into the positioning equation. This allows for real-time detection and processing of random anomalies in clock bias, thereby avoiding real-time PPP positioning result jumps caused by clock bias anomalies and improving the continuity and reliability of PPP-B2b real-time precise positioning results.

[0095] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0096] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0097] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0098] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0099] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A method for processing abnormal jump of PPP-B2b satellite clock error correction value, characterized in that, The method comprises the following steps: acquiring the clock correction value and broadcast ephemeris of GPS satellites and BDS-3 satellites through a user receiver; determining whether the GPS reference satellite is switched between the current epoch and the previous epoch according to the clock correction value of the GPS satellite; if the GPS reference satellite is switched between the current epoch and the previous epoch, calculating the reference change amount according to the clock correction value of the common view GPS satellite between the current epoch and the previous epoch, correcting the clock correction value of all visible GPS satellites in the current epoch according to the reference change amount to obtain the corrected clock correction value of the GPS satellite; superimposing the corrected clock correction value of the GPS satellite and the clock correction value of the BDS-3 satellite on the broadcast ephemeris to calculate the satellite clock difference parameter, and recovering the precise satellite clock difference according to the satellite clock difference parameter; differentially processing the precise satellite clock difference between the current epoch and the previous epoch to obtain the precise satellite clock difference value of each satellite; when the precise satellite clock difference value of the target satellite is greater than a preset threshold, determining that the clock correction value of the target satellite in the current epoch has an abnormal jump; determining whether the target satellite is a reference satellite; if not, initializing the clock abnormality processing parameter in the positioning observation equation of the target satellite to absorb the abnormal jump part of the clock correction value; if yes, initializing the clock abnormality processing parameter in the positioning observation equation of all satellites in the current epoch to absorb the abnormal jump part of the clock correction value.

2. The PPP-B2b satellite clock correction value abnormal jump processing method according to claim 1, wherein the type of the broadcast ephemeris is divided into GPS LNAV broadcast ephemeris and BDS-3 CNAV1 broadcast ephemeris. The method for determining whether the GPS reference satellite is switched between the current epoch and the previous epoch according to the clock correction value of the GPS satellite comprises the following steps:

3. The method for processing the abnormal jump of PPP-B2b satellite clock error correction value according to claim 2, characterized in that, acquiring the clock correction value of the GPS satellite in the previous epoch; comparing the clock correction value of the GPS satellite in the previous epoch with the clock correction value of the GPS satellite in the current epoch; if the clock correction value of a target GPS satellite in the current epoch is 0, taking the target GPS satellite as the GPS reference satellite, and determining whether the GPS reference satellite in the current epoch is consistent with the GPS reference satellite in the previous epoch; if not, determining that the GPS reference satellite is switched; if yes, determining that the GPS reference satellite is not switched; if the clock correction value of all GPS satellites in the current epoch is not 0, it is impossible to determine the GPS reference satellite, and it is determined that the GPS reference satellite is not switched; if the clock correction value of multiple GPS satellites in the current epoch is 0, taking the GPS reference satellite in the previous epoch as the GPS reference satellite in the current epoch, and determining that the GPS reference satellite is not switched. ​ 4. The method for processing PPP-B2b satellite clock correction value abnormal jump according to claim 3, characterized in that, The reference change amount is calculated according to the clock correction value of the common-view GPS satellite of the current epoch and the previous epoch, the clock correction value of all visible GPS satellites of the current epoch is corrected according to the reference change amount, and the corrected clock correction value of the GPS satellite is obtained, including: The clock correction value of the common-view GPS satellite of the current epoch and the previous epoch is differentially processed to obtain the differential value of each common-view GPS satellite; The average value of the differential values of all common-view GPS satellites is obtained to obtain the reference change amount between the current epoch and the previous epoch; The clock correction value of all visible GPS satellites of the current epoch is corrected by using the reference change amount to obtain the corrected clock correction value of the GPS satellite.

5. The method for processing PPP-B2b satellite clock correction value abnormal jump according to claim 4, characterized in that, The corrected clock correction value of the GPS satellite and the clock correction value of the BDS-3 satellite are superimposed on the broadcast ephemeris to obtain the satellite clock difference parameter, and the precise satellite clock difference is recovered according to the satellite clock difference parameter, including: superimposing the correction value of the modified clock difference of the GPS satellite and the correction value of the clock difference of the BDS-3 satellite to the broadcast ephemeris, the satellite clock difference parameter calculated ; According to the satellite clock error parameter The precise satellite clock error is recovered The calculation formula is: ； Among them, the Indicates the speed of light under vacuum conditions; the Indicates the preset clock correction value, which is preset according to the PPP-B2b correction product.

6. The method for processing PPP-B2b satellite clock correction value abnormal jump according to claim 1, characterized in that, After the corrected clock correction value of the GPS satellite and the clock correction value of the BDS-3 satellite are superimposed on the broadcast ephemeris to obtain the satellite clock difference parameter, and the precise satellite clock difference is recovered according to the satellite clock difference parameter, it further includes: A clock difference abnormality processing parameter is commonly added to the positioning observation equation of the pseudorange and carrier phase of each satellite and each frequency of the PPP-B2b, the satellite with the highest elevation angle in the first epoch is selected as the reference satellite in the subsequent epoch, and the value of the positioning observation equation of the reference satellite is set to 0 to eliminate the rank defect of the positioning observation equation; The GPS / BDS-3 double-system double-frequency non-combination real-time PPP positioning model of the PPP-B2b is represented as: ； ； Wherein, the C represents BDS-3; the G represents GPS; the s represents satellite identification; the r represents user receiver; the j represents satellite signal frequency; the and the respectively represent pseudo-range observation value of the BDS-3 satellite and the GPS satellite minus calculated value; the and the respectively represent carrier phase observation value of the BDS-3 satellite and the GPS satellite minus calculated value; the and the respectively represent station-star line-of-sight unit vector of the BDS-3 satellite and the GPS satellite; the represents three-dimensional position of the user receiver r; the represents product of light speed and receiver clock bias estimated by the BDS-3 satellite, the represents product of light speed and receiver clock bias estimated by the GPS satellite, the and the respectively absorb pseudo-range hardware delay of the BDS-3 satellite and the GPS satellite at user receiver end; the and the respectively represent troposphere projection coefficient of the BDS-3 satellite and the GPS satellite; the represents troposphere zenith direction wet delay at user receiver end; the and the respectively represent ionosphere conversion coefficient of the BDS-3 satellite and the GPS satellite; the and the respectively represent ionosphere delay estimation value on the inclined path of the first frequency of the BDS-3 satellite and the GPS satellite, the only absorbs pseudo-range hardware delay at user receiver end, the absorbs pseudo-range hardware delay at user receiver end, while absorbing uncorrected pseudo-range hardware delay at GPS satellite end; the and the respectively represent the BDS-3 satellite and the GPS satellite; the and the respectively represent BDS-3 satellite and GPS satellite jth frequency absorbing pseudo-range hardware delay and phase hardware delay at satellite end, while absorbing pseudo-range hardware delay and phase hardware delay at user receiver end; the and the respectively represent clock bias anomaly processing parameters added in the positioning observation equation of the BDS-3 satellite and the GPS satellite.

7. The PPP-B2b satellite clock correction value abnormal jump processing method according to claim 6, characterized in that, The satellite clock difference of the PPP-B2b presents a relatively stable feature within each continuous arc, and the clock difference abnormality processing parameter is set as a random walk process. 8.A system for processing abnormal jump of PPP-B2b satellite clock error correction value, characterized in that, including: A data acquisition module for acquiring the clock correction value of the GPS satellite and the clock correction value of the BDS-3 satellite and the broadcast ephemeris of the PPP-B2b through a user receiver; A GPS reference satellite switching determination module for determining whether the GPS reference satellite of the current epoch and the previous epoch is switched according to the clock correction value of the GPS satellite; A GPS satellite clock correction module for calculating a reference change amount according to the clock correction value of the common-view GPS satellite of the current epoch and the previous epoch if the GPS reference satellite of the current epoch and the previous epoch is switched, correcting the clock correction value of all visible GPS satellites of the current epoch according to the reference change amount, and obtaining the corrected clock correction value of the GPS satellite; A satellite clock recovery module for superimposing the corrected clock correction value of the GPS satellite and the clock correction value of the BDS-3 satellite on the broadcast ephemeris to obtain the satellite clock difference parameter, and recovering the precise satellite clock difference according to the satellite clock difference parameter; an abnormal jump detection module, configured to perform differential processing on the precise satellite clock errors of the current epoch and the previous epoch to obtain a precise satellite clock error differential value of each satellite; when the precise satellite clock error differential value of a target satellite is greater than a preset threshold value, it is determined that the clock error correction value of the target satellite at the current epoch has an abnormal jump; an abnormal jump processing module, configured to determine whether the target satellite is a reference satellite; if not, a clock error abnormality processing parameter in a positioning observation equation of the target satellite is initialized, so as to absorb the abnormal jump part of the clock error correction value; if yes, clock error abnormality processing parameters in positioning observation equations of all satellites at the current epoch are initialized, so as to absorb the abnormal jump part of the clock error correction value.

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