Beidou four-frequency precise point positioning method and system based on satellite-based enhancement service

Abstract

The invention discloses a Beidou four-frequency precise point positioning method and system based on satellite-based enhancement service. The method comprises the following steps: receiving and decoding a Beidou four-frequency signal, a PPP-B2b signal and a broadcast ephemeris in real time; the correction information in the PPP-B2b signal is matched with the corresponding information in the broadcast ephemeris; applying the orbit correction information to a broadcast ephemeris orbit; applying the clock error correction information to the broadcast ephemeris clock error; a Beidou four-frequency ionosphere-free dual-combination positioning model is constructed; correcting orbits and clock error parameters of the model; unifying the receiver end clock error in the ionosphere-free combination observation equation of B1C / B2a, and linearizing the corrected model; and resolving the Beidou four-frequency ionosphere-free dual-combination positioning model to obtain a high-precision receiver position coordinate. According to the invention, the problems of low positioning precision and slow convergence speed in dual-frequency PPP-B2b positioning can be solved.

Description

Technical Field

[0001] The present invention belongs to the field of high-precision positioning in satellite positioning technology, and specifically relates to a Beidou quad-frequency precise single-point positioning method, system, equipment and storage medium based on satellite-based augmentation service. Background Art

[0002] Satellite-based augmentation services can provide users with high-precision global navigation satellite system (GNSS) product services. For example, the centimeter-level augmentation service (CLAS) provided by the QZSS system, the global high-precision service (HAS) provided by the Galileo system, and the PPP-B2b service launched by China's BeiDou-3 (BeiDou Navigation Satellite System) all belong to this category of high-precision positioning. Among them, the PPP-B2b service uses the PPP-B2b signals from three BeiDou-3 geostationary orbit (GEO) satellites to broadcast precise point positioning (PPP) correction information in real time to users in China and its surrounding areas. Even in an environment without network connection, users can directly obtain high-precision orbit and clock information, which greatly broadens the application scenarios of high-precision positioning services. Thanks to the BDS-3 intersatellite link observation, the orbit accuracy of BeiDou-3 is relatively high. Therefore, after B2b correction, the real-time precise orbit of BDS-3MEO satellite is basically consistent with the orbit error of broadcast ephemeris, but it effectively improves the problem of discontinuous changes in the orbit error sequence caused by broadcast ephemeris update. In terms of clock error, the average accuracy of BeiDou-3's PPP-B2b clock error is better than 0.3ns. The high-precision PPP-B2b satellite orbit and clock error can provide users with high-precision services in environments and scenarios where the network cannot be covered or the coverage is unstable, and provide a stable and reliable high-precision positioning solution for remote areas such as Gobi and sea areas where CORS services are difficult to reach or base station construction is extremely inconvenient.

[0003] The integration of multiple frequencies and multiple systems has become an irreversible development trend of precise point positioning (PPP) technology. The four positioning frequency band signals of B1I, B3I, B1C and B2a currently supported by the BeiDou-3 system contain rich redundant information resources. Fully exploring and utilizing BeiDou's four-frequency signals can not only significantly improve the speed of ambiguity fixation, but also further optimize the accuracy of parameter estimation. However, the current PPP-B2b service mainly focuses on the application of dual-frequency signals and has not yet fully released the potential of BeiDou's four-frequency signals, which to a certain extent limits the further improvement of positioning accuracy and the shortening of convergence time. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a Beidou quad-frequency precise point positioning method, system, device and storage medium based on satellite-based augmentation service, which can fully integrate the advantages of PPP-B2b service and the resources of Beidou quad-frequency signal, so as to ensure the positioning accuracy while greatly shortening the convergence time.

[0005] Technical solution: The present invention provides a Beidou quad-frequency precise point positioning method based on satellite-based augmentation service, comprising:

[0006] Signal reception and decoding: Receive the Beidou B1I, B3I, B1C and B2a positioning frequency band signals, as well as PPP-B2b signals and broadcast ephemeris in real time, decode all received signals, and extract original observation data and broadcast ephemeris information;

[0007] Data matching: Match the correction information obtained by decoding the PPP-B2b signal with the corresponding information in the broadcast ephemeris, including matching the correction information type based on IOD SSR, matching the clock error of IODP with the orbit correction information, matching the correction number of IOD Corr with the satellite PRN, and matching the correction information based on IODN with the broadcast ephemeris;

[0008] Precision orbit acquisition: Apply the orbit correction information in the PPP-B2b signal to the broadcast ephemeris orbit to obtain precise real-time satellite orbit coordinates;

[0009] Precise clock error acquisition: Apply the clock error correction information in the PPP-B2b signal to the broadcast ephemeris clock error to obtain accurate real-time satellite clock error;

[0010] Model construction: Based on the extracted original observation data, according to the frequency combinations of B1I / B3I and B1C / B2a, ionosphere-free combined observation equations are constructed respectively to eliminate the first-order delay of the ionosphere. The two ionosphere-free combined observation equations are used as a Beidou four-frequency ionosphere-free dual combination positioning model.

[0011] Precise orbit / clock correction: Taking the calculated real-time satellite orbit coordinates and real-time satellite clock errors as known values, the orbit and clock error parameters in the Beidou four-frequency ionosphere-free dual-combination positioning model are corrected to obtain the corrected Beidou four-frequency ionosphere-free dual-combination positioning model;

[0012] Unification of receiver clock errors: Taking the clock error in the ionosphere-free combined observation equation of B1I / B3I as the benchmark, unify the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a, so as to ensure the consistency of the receiver clock error in the combined observation values ​​of different frequency bands. Use the BeiDou-3 DCB correction information in the PPP-B2b signal to linearize the corrected BeiDou four-frequency ionosphere-free dual combination positioning model.

[0013] Positioning solution: The Kalman filter algorithm is used to solve the linearized Beidou four-frequency ionosphere-free dual-combination positioning model to obtain high-precision receiver position coordinates.

[0014] Further, by checking the IOD SSR, it is confirmed whether the correction information in the received PPP-B2b signal is generated by the same system configuration, thereby achieving matching of the correction information type;

[0015] IODP is used to match the satellite clock correction information with the corresponding mask information. At the same time, the satellite orbit correction number is directly matched with the corresponding satellite number through the mask information to ensure that the orbit and clock correction numbers can be correctly associated with their respective satellites, thereby achieving matching of clock and orbit correction information.

[0016] Furthermore, IOD Corr is used to further accurately match the clock correction number and orbit correction number with their respective corresponding satellite PRN numbers, thereby achieving matching between the correction number and the satellite PRN;

[0017] By checking the IODN in the PPP-B2b correction information and the IODC parameters in the broadcast ephemeris, the PPP-B2b correction information is matched with the broadcast ephemeris, so that the correction information and the broadcast ephemeris are matched.

[0018] Furthermore, the orbit correction information in the PPP-B2b signal is applied to the broadcast ephemeris orbit to obtain accurate real-time satellite orbit coordinates, including:

[0019] Calculate the real-time satellite orbit coordinates as follows:

[0020]

[0021] In the formula, are the radial, tangential and normal corrections for the PPP-B2b orbit; are the radial, tangential and normal direction unit vectors respectively; and are the position and velocity vectors in the Earth-centered Earth-fixed coordinate system respectively; Real-time precise satellites obtained after PPP-B2b orbit correction for broadcast ephemeris; is the satellite position vector calculated from the broadcast ephemeris.

[0022] Furthermore, the clock correction information in the PPP-B2b signal is applied to the broadcast ephemeris clock error to obtain accurate real-time satellite clock errors, including:

[0023] Calculate the real-time satellite clock error. The expression is as follows:

[0024]

[0025] In the formula, Indicates the corrected real-time precise clock error; represents the broadcast ephemeris satellite clock error; d clkrepresents the PPP-B2b clock correction; c represents the speed of light.

[0026] Furthermore, based on the extracted original observation data, according to the frequency combinations of B1I / B3I and B1C / B2a, ionospheric-free combined observation equations are constructed to eliminate the first-order delay of the ionosphere. The two ionospheric-free combined observation equations are used as a Beidou four-frequency ionospheric-free dual-combination positioning model, including:

[0027] Define B1I as the first frequency, B3I as the second frequency, B1C as the third frequency, and B2a as the fourth frequency

[0028]

[0029] in:

[0030]

[0031] Where s and r are GNSS satellite and user receiver respectively; IF 12 The ionospheric-free combination of frequencies 1 and 2; IF 34 An ionospheric-free combination of bands 3 and 4; are the ionospheric-free pseudorange observations of frequencies 1 and 2 between satellite s and receiver r; is the ionospheric-free pseudorange observation value of frequencies 3 and 4 between satellite s and receiver r; are the ionospheric-free carrier observations of frequencies 1 and 2 between satellite s and the receiver; are the ionospheric-free carrier observations of frequencies 3 and 4 between satellite s and the receiver; is the geometric distance between the receiver and the satellite; is the ionospheric-free combined clock error of frequencies 1 and 2 at the receiver; is the ionospheric-free combined clock error of frequencies 3 and 4 at the receiver, is the clock difference between the receiver and the satellite; is the tropospheric delay between the GNSS satellite s and the user receiver r; It is the B3I reference frequency pseudorange hardware delay on the satellite side; The ionospheric pseudorange hardware delay is free for satellite s frequencies 1 and 2; Ionospheric pseudorange hardware delay for satellite s frequencies 3 and 4; is the ionospheric-free float resolution of the frequency combination 1 and 2 in satellite s and receiver r, is the ionospheric-free float resolution of the frequency combination 3 and 4 in satellite s and receiver r; is the ionospheric-free wavelength of the combination of frequencies 1 and 2; is the ionospheric-free wavelength for the combination of frequencies 3 and 4; and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier for frequencies 1 and 2 of satellite s and receiver r, respectively; and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier frequencies 3 and 4 for satellite s and receiver r, respectively; dt r is the receiver clock error; is the pseudorange hardware delay of the ionosphere-free combination of receiver r frequencies 1 and 2; is the pseudorange hardware delay of the ionosphere-free combination of receiver r frequencies 3 and 4; is the ionospheric-free combined ambiguity of the frequency 1 and 2 combination of satellite s and receiver r; is the ionospheric-free combined ambiguity for the combination of frequencies 3 and 4 of satellite s and receiver r; There is no ionospheric carrier hardware delay for frequencies 1 and 2 at the receiver end; No ionospheric carrier hardware delay for receiver frequencies 3 and 4; Indicates the hardware delay of the ionosphere-free combined carrier of satellite frequency 1 and 2; Indicates the hardware delay of the ionosphere-free combined carrier of satellite frequencies 3 and 4.

[0032] Furthermore, the clock error in the ionosphere-free combined observation equation of B1I / B3I is used as the benchmark to unify the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a, thereby ensuring the consistency of the receiver clock error in the combined observation values ​​of different frequency bands. The BeiDou-3 DCB correction information in the PPP-B2b signal is used to linearize the corrected BeiDou four-frequency ionosphere-free dual combination positioning model, including:

[0033] Taking the clock error in the ionosphere-free combined observation equation of B1I / B3I as the benchmark, the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a is unified, and the linearized equation of the ionosphere-free combined pseudorange and carrier observation is obtained as follows:

[0034]

[0035] In the formula, represents the linearized ionospheric-free pseudorange observation value of the frequency combination 1 and 2 between satellites s and r, represents the linearized ionospheric-free pseudorange observation value of the frequency combination 3 and 4 between satellites s and r, represents the linearized carrier-free ionosphere-free observation value of the frequency combination 1 and 2 between satellites s and r, represents the linearized carrier-free ionosphere observation value of the frequency combination 3 and 4 between satellites s and r, and dX represents the position parameter to be estimated; is the coefficient of the unknown position parameter dX between satellites s and r after linearization; It represents the ionospheric-free combined clock error of frequencies 1 and 2 at the receiver end. is the tropospheric projection function of satellites s and r, T is the tropospheric delay; and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier frequencies 1 and 2 for satellite s and receiver r, respectively, and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier frequencies 3 and 4 for satellite s and receiver r, respectively; other symbols are as follows:

[0036]

[0037] Where, f1, f2, f3, and f4 represent the frequency values ​​of frequencies 1, 2, 3, and 4 respectively; Respectively represent the code deviation between satellite frequency points 1, 2, 3, 4 and the reference frequency B3I; DCB r,12 Indicates the code deviation of frequency 1 and frequency 2 at the receiver; Indicates the ionosphere-free receiver clock error between frequencies 1 and 2 and the ionosphere-free combined receiver clock error between frequencies 3 and 4, DCB r,34 Indicates the code deviation of frequency 3 and frequency 4 at the receiver end; Indicates that IF 12 As the benchmark, the reconstructed ambiguity parameters are obtained.

[0038] Based on the same inventive concept, a Beidou quad-frequency precise point positioning system based on satellite-based augmentation service of the present invention comprises:

[0039] The signal receiving and decoding module is used to receive the Beidou B1I, B3I, B1C and B2a positioning frequency band signals, as well as the PPP-B2b signal and broadcast ephemeris in real time, decode all received signals, and extract the original observation data and broadcast ephemeris information;

[0040] Data matching module, used to match the correction information obtained by decoding the PPP-B2b signal with the corresponding information in the broadcast ephemeris, including matching the correction information type based on IOD SSR, matching the clock error of IODP with the orbit correction information, matching the correction number of IOD Corr with the satellite PRN, and matching the correction information based on IODN with the broadcast ephemeris;

[0041] Precision orbit acquisition module, used to apply the orbit correction information in the PPP-B2b signal to the broadcast ephemeris orbit to obtain accurate real-time satellite orbit coordinates;

[0042] The precise clock error acquisition module is used to apply the clock error correction information in the PPP-B2b signal to the broadcast ephemeris clock error to obtain the precise real-time satellite clock error;

[0043] The model building module is used to construct ionosphere-free combined observation equations based on the extracted original observation data and the frequency combinations of B1I / B3I and B1C / B2a to eliminate the first-order delay of the ionosphere. The two ionosphere-free combined observation equations are used as a Beidou four-frequency ionosphere-free dual-combination positioning model.

[0044] The precise orbit / clock correction module is used to take the calculated real-time satellite orbit coordinates and real-time satellite clock errors as known values, and correct the orbit and clock error parameters in the Beidou four-frequency ionosphere-free dual-combination positioning model to obtain the corrected Beidou four-frequency ionosphere-free dual-combination positioning model;

[0045] The receiver clock error unification module is used to unify the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a based on the clock error in the ionosphere-free combined observation equation of B1I / B3I, so as to ensure the consistency of the receiver clock error in the combined observation values ​​of different frequency bands, and use the Beidou-3 DCB correction information in the PPP-B2b signal to linearize the corrected Beidou four-frequency ionosphere-free dual combination positioning model;

[0046] The positioning solution module is used to use the Kalman filter algorithm to solve the linearized Beidou four-frequency ionosphere-free dual combination positioning model to obtain high-precision receiver position coordinates.

[0047] Based on the same inventive concept, a Beidou quad-frequency precise point positioning device based on satellite-based augmented service of the present invention includes a processor and a memory, wherein the memory stores computer instructions, and the processor is used to execute the computer instructions stored in the memory. When the computer instructions are executed by the processor, the electronic device implements the steps of the above-mentioned Beidou quad-frequency precise point positioning method based on satellite-based augmented service.

[0048] Based on the same inventive concept, a computer-readable storage medium of the present invention stores a computer program thereon, which, when executed by a processor, implements the steps of the above-mentioned Beidou quad-frequency precise point positioning method based on satellite-based augmented service.

[0049] Beneficial effects: Compared with the prior art, the significant technical effects of the present invention are:

[0050] The present invention fully integrates the advantages of PPP-B2b service and the resources of Beidou quad-frequency signal, in order to significantly shorten the convergence time while ensuring positioning accuracy, and open up a new path for the wide application and performance optimization of Beidou satellite-based augmentation system.

[0051] The present invention makes full use of the observation information of the four frequency bands B1I, B3I, B1C and B2a provided by the BeiDou-3 system, and effectively eliminates the influence of ionospheric delay on positioning accuracy by constructing an ionosphere-free combination model, thereby improving positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a flowchart of a Beidou quad-frequency precise point positioning method based on satellite-based augmentation service disclosed in an embodiment of the present invention;

[0053] Figure 2 This is a diagram of the Beidou quad-frequency signal reception situation of a certain reference station disclosed in an embodiment of the present invention;

[0054] Figure 3 It is a schematic diagram of the number of Beidou satellites (BDS) that can be received by a certain reference station and the number of Beidou satellites (PPP-B2b BDS) that can be used for positioning after the broadcast ephemeris is matched with the PPP-B2b signal disclosed in an embodiment of the present invention;

[0055] Figure 4 It is a schematic diagram of a Beidou dual-frequency PPP-B2b static positioning result of a reference station disclosed in an embodiment of the present invention;

[0056] Figure 5 It is a schematic diagram of the Beidou quad-frequency PPP-B2b static positioning result of a certain reference station disclosed in an embodiment of the present invention;

[0057] Figure 6 It is a schematic diagram of a Beidou dual-frequency PPP-B2b simulated dynamic positioning result of a certain reference station disclosed in an embodiment of the present invention;

[0058] Figure 7 It is a schematic diagram of the Beidou quad-frequency PPP-B2b simulated dynamic positioning result of a certain reference station disclosed in an embodiment of the present invention;

[0059] Figure 8 It is a structural schematic diagram of a Beidou quad-frequency precise point positioning system based on satellite-based augmentation service disclosed in an embodiment of the present invention;

[0060] Fig. 9 It is a structural schematic diagram of a Beidou quad-frequency precise single-point positioning device based on satellite-based augmented service disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0061] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It will be understood by those skilled in the art that the purposes and advantages that can be achieved with the present invention are not limited to the specific description of the above beneficial effects, and the above and other purposes that can be achieved by the present invention will be more clearly understood based on the following detailed description.

[0062] It should be understood by those skilled in the art that the exemplary components, systems and methods described in conjunction with the embodiments disclosed in the present invention can be implemented in hardware, software or a combination of the two. Whether it is implemented in hardware or software depends on the specific application and design of the technical solution. Professional and technical personnel can use different methods to implement the functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0063] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0064] Example 1

[0065] See also Figure 1 , Figure 1 : is a flowchart of a Beidou quad-frequency precise point positioning method based on satellite-based augmentation service disclosed in an embodiment of the present invention. Figure 1 The Beidou quad-frequency precise point positioning method described is applied to satellite positioning, such as precise point positioning, etc., which is not limited in the embodiments of the present invention. Figure 1 As shown, the Beidou quad-frequency precise point positioning method based on satellite-based augmentation service may include the following operations:

[0066] S1. Signal reception and decoding: Figure 2 As shown in the figure, it receives the four positioning frequency band signals of Beidou B1I, B3I, B1C and B2a, as well as PPP-B2b (satellite-based augmentation service) signals and broadcast ephemeris in real time, decodes all received signals, and extracts the original observation data (pseudorange and carrier phase observation values) and broadcast ephemeris information. The original observation data is used for subsequent high-precision positioning.

[0067] In this embodiment, Beidou quad-frequency observation data and PPP-B2b signals are collected in an open environment and decoded. In the present invention, the PPP-B2b information to be decoded includes satellite masks, orbit corrections, clock corrections and DCB.

[0068] S2. Data matching: Decoding the PPP-B2b signal to obtain the correction information Broadcast EphemerisThe four key steps are to match the corresponding information in the correction information, including matching the correction information type based on IOD SSR, matching the clock error of IODP with the orbit correction information, matching the correction number of IOD Corr with the satellite PRN, and matching the correction information based on IODN with the broadcast ephemeris.

[0069] (1) Correction information type matching based on IOD SSR: By checking the IOD SSR (IOD identifier of the SSR correction information), it is confirmed whether the correction information in the received PPP-B2b signal of orbit, clock, etc. is generated by the same system configuration, thereby achieving correction information type matching. This step ensures the consistency of all correction information in time and space.

[0070] (2) Matching the clock and orbit correction information using IODP: Use IODP (IOD identifier of clock correction information) to match the satellite clock correction information with the corresponding mask information. The purpose of this step is to determine the satellite PRN (pseudo-random noise) number to which each satellite clock correction number belongs. At the same time, the satellite orbit correction number is directly matched with the corresponding satellite number through the mask information to ensure that the orbit and clock correction numbers can be correctly associated with their respective satellites.

[0071] (3) Matching the corrections with the satellite PRN through IOD Corr: After confirming the satellite affiliation of the clock and orbit corrections, the clock and orbit corrections are further accurately matched with their corresponding satellite PRN numbers using IOD Corr (IOD identifier of the correction information).

[0072] (4) Matching correction information based on IODN with broadcast ephemeris: By checking the IODN (navigation data identifier of correction information) in the PPP-B2b correction information and the IODC (IOD identifier of ephemeris data) parameters in the broadcast ephemeris, the matched PPP-B2b correction information is matched with the broadcast ephemeris. This step ensures that the correction information can be applied to the broadcast ephemeris in real time and accurately to correct the precise orbit and clock errors.

[0073] S3, Precision Orbit Acquisition: Apply the orbit correction information in the PPP-B2b signal to the broadcast ephemeris orbit to obtain more accurate real-time satellite orbit coordinates.

[0074] In this embodiment, the PPP-B2b satellite orbit correction information is corrected for the calculation result of the broadcast ephemeris to obtain accurate real-time satellite orbit coordinates. The real-time satellite orbit coordinates are calculated as follows:

[0075]

[0076] In the formula, are the radial, tangential and normal corrections for the PPP-B2b orbit; are the radial, tangential and normal direction unit vectors respectively; and are the position and velocity vectors in the Earth-centered Earth-fixed coordinate system respectively; Real-time precise satellites obtained after PPP-B2b orbit correction for broadcast ephemeris; is the satellite position vector calculated from the broadcast ephemeris.

[0077] S4. Precision clock error acquisition: Apply the clock error correction information in the PPP-B2b signal to the broadcast ephemeris clock error to obtain a more accurate real-time satellite clock error.

[0078] In this embodiment, the PPP-B2b satellite clock correction information is corrected for the calculation result of the broadcast ephemeris to obtain an accurate real-time satellite clock error. The real-time satellite clock error is calculated as follows:

[0079]

[0080] In the formula, Indicates the corrected real-time precise clock error; represents the broadcast ephemeris satellite clock error; d clk represents the PPP-B2b clock correction; c represents the speed of light.

[0081] S5. Model construction: Based on the original observation data extracted in S1, the ionosphere-free combined observation equations are constructed according to the frequency combinations of B1I / B3I and B1C / B2a to eliminate the first-order delay of the ionosphere. The two ionosphere-free combined observation equations are used as a whole as the Beidou four-frequency ionosphere-free dual combination positioning model.

[0082] In this embodiment, B1I is defined as the first frequency, B3I is defined as the second frequency, B1C is defined as the third frequency, and B2a is defined as the fourth frequency;

[0083] According to the first and second frequencies, the third and fourth frequencies, the ionospheric first-order delay effect is eliminated by ionospheric combination, and the Beidou four-frequency ionospheric dual combination positioning model is constructed. The expression is as follows:

[0084]

[0085] in:

[0086]

[0087] Where s and r are GNSS satellite and user receiver respectively; IF 12 The ionospheric-free combination of frequencies 1 and 2; IF 34 An ionospheric-free combination of bands 3 and 4; represents the ionospheric-free pseudorange observations of frequencies 1 and 2 between satellite s and receiver r; represents the ionospheric-free pseudorange observations of frequencies 3 and 4 between satellite s and receiver r; represents the ionospheric-free carrier observations of frequencies 1 and 2 between satellite s and the receiver; represents the ionospheric-free carrier observations of frequencies 3 and 4 between satellite s and the receiver; is the geometric distance between the receiver and the satellite; is the ionospheric-free combined clock error of frequencies 1 and 2 at the receiver; is the ionospheric-free combined clock error of frequencies 3 and 4 at the receiver, is the clock difference between the receiver and the satellite; is the tropospheric delay between the GNSS satellite s and the user receiver r; It is the B3I reference frequency pseudorange hardware delay on the satellite side; The ionospheric pseudorange hardware delay is free for satellite s frequencies 1 and 2; Ionospheric pseudorange hardware delay for satellite s frequencies 3 and 4; is the ionospheric-free float resolution of the frequency combination 1 and 2 in satellite s and receiver r, is the ionospheric-free float resolution of the frequency combination 3 and 4 in satellite s and receiver r; is the ionospheric-free wavelength of the combination of frequencies 1 and 2; is the ionospheric-free wavelength for the combination of frequencies 3 and 4; and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier for frequencies 1 and 2 of satellite s and receiver r, respectively; and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier frequencies 3 and 4 for satellite s and receiver r, respectively; dt r is the receiver clock error; is the pseudorange hardware delay of the ionosphere-free combination of receiver r frequencies 1 and 2; is the pseudorange hardware delay of the ionosphere-free combination of receiver r frequencies 3 and 4; is the ionospheric-free combined ambiguity of the frequency 1 and 2 combination of satellite s and receiver r; is the ionospheric-free combined ambiguity for the combination of frequencies 3 and 4 of satellite s and receiver r; There is no ionospheric carrier hardware delay for frequencies 1 and 2 at the receiver end; No ionospheric carrier hardware delay for receiver frequencies 3 and 4; Indicates the hardware delay of the ionosphere-free combined carrier of satellite frequency 1 and 2; Indicates the hardware delay of the ionosphere-free combined carrier of satellite frequencies 3 and 4.

[0088] S6, precise orbit / clock correction: taking the calculated real-time satellite orbit coordinates and real-time satellite clock errors as known values, the orbit and clock error parameters in the Beidou four-frequency ionosphere-free dual combination positioning model of step S5 are corrected to obtain the corrected Beidou four-frequency ionosphere-free dual combination positioning model. By applying the precise orbit and clock error obtained in steps S3 and S4 to the Beidou four-frequency ionosphere-free dual combination positioning model, the accuracy of the observation equation is improved.

[0089] S7. Unification of receiver clock errors: Taking the clock error in the ionosphere-free combined observation equation of B1I / B3I as the benchmark, unify the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a to ensure the consistency of the receiver clock error in the combined observation values ​​of different frequency bands. Use the BeiDou-3 DCB correction information in the PPP-B2b signal to linearize the corrected BeiDou four-frequency ionosphere-free dual combination positioning model.

[0090] Taking the clock error in the ionosphere-free combined observation equation of B1I / B3I as the benchmark, the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a is unified, and the linearized equation of the ionosphere-free combined pseudorange and carrier observation is obtained as follows:

[0091]

[0092] In the formula, represents the linearized ionospheric-free pseudorange observation value of the frequency combination 1 and 2 between satellites s and r, represents the linearized ionospheric-free pseudorange observation value of the frequency combination 3 and 4 between satellites s and r, represents the linearized carrier-free ionosphere-free observation value of the frequency combination 1 and 2 between satellites s and r, represents the linearized carrier-free ionosphere observation value of the frequency combination 3 and 4 between satellites s and r, and dX represents the position parameter to be estimated; is the coefficient of the unknown position parameter dX between satellites s and r after linearization; It represents the ionospheric-free combined clock error of frequencies 1 and 2 at the receiver end. is the tropospheric projection function of satellites s and r, T is the tropospheric delay; and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier frequencies 1 and 2 for satellite s and receiver r, respectively, and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier frequencies 3 and 4 for satellite s and receiver r, respectively; other symbols are as follows:

[0093]

[0094] Where, f1, f2, f3, and f4 represent the frequency values ​​of frequencies 1, 2, 3, and 4 respectively; Respectively represent the code deviation between satellite frequency points 1, 2, 3, 4 and the reference frequency B3I; DCB r,12 Indicates the code deviation of frequency 1 and frequency 2 at the receiver; Indicates the ionosphere-free receiver clock error between frequencies 1 and 2 and the ionosphere-free combined receiver clock error between frequencies 3 and 4, DCB r,34 Indicates the code deviation of frequency 3 and frequency 4 at the receiver end; Indicates that IF 12 As the benchmark, the reconstructed ambiguity parameters are obtained.

[0095] S8. Positioning solution: The linearized Beidou quad-frequency ionosphere-free dual-combination positioning model is solved using the Kalman filter algorithm to obtain high-precision receiver position coordinates, and the positioning accuracy and reliability of the present invention are verified by comparing with known reference points or actual positions.

[0096] The observation data of a certain base station on December 10, 2023 and the PPP-B2b data of the corresponding time were collected to compare the four-frequency model and the dual-frequency model proposed in the present invention. In addition, static and simulated dynamic experimental schemes were used to verify the improvement of the present invention. Figure 4 and Figure 5 Indicates the dual-frequency and quad-frequency positioning results in static conditions. Figure 6 and Figure 7 Indicates the dual-frequency and quad-frequency positioning results in the simulated dynamic situation. After convergence, the specific positioning results are as follows:

[0097] Table 1 Comparison of static and dynamic results of two schemes

[0098]

[0099] From Table 1 and Figure 4 , Figure 5 It can be seen that after convergence, in the static case, the positioning accuracy of the two schemes in the three directions of E, N, and U is at the centimeter level, but in comparison, the accuracy of the method proposed in the present invention is improved by 80%, 0%, and 50%. In the dynamic case, from Table 1 and Figure 6 , Figure 7 It can be seen that the positioning accuracy of the two solutions can reach the decimeter level, but the accuracy of the method proposed in the present invention is improved by 31.2%, 50% and 16.6%. Figure 6 and Figure 7 It can be seen that the convergence speed of the method proposed in the present invention is significantly faster than that of the traditional dual-frequency positioning method.

[0100] In summary, the present invention proposes an innovative solution to the shortcomings of the traditional PPP-B2b positioning technology based on dual-frequency signals in positioning accuracy - the Beidou four-frequency ionosphere-free combined positioning method based on Beidou PPP-B2b service. This method makes full use of the observation information of the four frequency bands B1I, B3I, B1C and B2a provided by the Beidou-3 system, and by constructing an ionosphere-free combination model, it effectively eliminates the influence of ionospheric delay on positioning accuracy and improves positioning accuracy. The experimental results using the Beidou four-frequency and PPP-B2b observation information of a certain reference station as a solution case show that the Beidou four-frequency ionosphere-free positioning method based on Beidou PPP-B2b service described in the present invention can achieve static centimeter-level and dynamic decimeter-level positioning accuracy.

[0101] Example 2

[0102] See also Figure 8 , Figure 8 1 is a schematic diagram of a Beidou quad-frequency precise point positioning system based on satellite-based augmentation service disclosed in an embodiment of the present invention. The system can perform precise point positioning and specifically includes:

[0103] The signal receiving and decoding module is used to receive the Beidou B1I, B3I, B1C and B2a positioning frequency band signals, as well as the PPP-B2b signal and broadcast ephemeris in real time, decode all received signals, and extract the original observation data and broadcast ephemeris information;

[0104] A data matching module is used to match the correction information obtained by decoding the PPP-B2b signal with the corresponding information in the broadcast ephemeris, including matching of correction information types, matching of clock correction numbers with mask information, matching of clock correction numbers with orbit correction numbers, and matching of orbit correction numbers with broadcast ephemeris;

[0105] Precision orbit acquisition module, used to apply the orbit correction information in the PPP-B2b signal to the broadcast ephemeris orbit to obtain accurate real-time satellite orbit coordinates;

[0106] The precise clock error acquisition module is used to apply the clock error correction information in the PPP-B2b signal to the broadcast ephemeris clock error to obtain the precise real-time satellite clock error;

[0107] The model building module is used to construct ionosphere-free combined observation equations according to the frequency combinations of B1I / B3I and B1C / B2a to eliminate the first-order delay of the ionosphere. The two ionosphere-free combined observation equations are used as a Beidou four-frequency ionosphere-free dual-combination positioning model.

[0108] The precise orbit / clock correction module is used to take the calculated real-time satellite orbit coordinates and real-time satellite clock errors as known values, and correct the orbit and clock error parameters in the Beidou four-frequency ionosphere-free dual-combination positioning model to obtain the corrected Beidou four-frequency ionosphere-free dual-combination positioning model;

[0109] The receiver clock error unification module is used to unify the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a based on the clock error in the ionosphere-free combined observation equation of B1I / B3I, so as to ensure the consistency of the receiver clock error in the combined observation values ​​of different frequency bands, and use the Beidou-3 DCB correction information in the PPP-B2b signal to linearize the corrected Beidou four-frequency ionosphere-free dual combination positioning model;

[0110] The positioning solution module is used to use the Kalman filter algorithm to solve the linearized Beidou four-frequency ionosphere-free dual combination positioning model to obtain high-precision receiver position coordinates.

[0111] In an optional embodiment, the Beidou quad-frequency precise point positioning method based on satellite-based augmentation service includes: a) receiving Beidou B1I, B3I, B1C and B2a four positioning frequency band signals, as well as PPP-B2b signals and broadcast ephemeris in real time, and decoding all received signals; b) matching the correction information obtained by decoding the PPP-B2b signal with the corresponding information in the broadcast ephemeris; c) applying the orbit correction information in the PPP-B2b signal to the broadcast ephemeris orbit to obtain accurate real-time satellite orbit coordinates; d) applying the clock correction information in the PPP-B2b signal to the broadcast ephemeris orbit to obtain accurate real-time satellite orbit coordinates; Used for broadcasting ephemeris clock error to obtain accurate real-time satellite clock error; e) construct Beidou four-frequency ionosphere-free dual combination positioning model; f) correct the orbit and clock error parameters in the Beidou four-frequency ionosphere-free dual combination positioning model; g) based on the clock error in the ionosphere-free combination observation equation of B1I / B3I, unify the receiver-end clock error in the ionosphere-free combination observation equation of B1C / B2a, and linearize the corrected Beidou four-frequency ionosphere-free dual combination positioning model; h) solve the linearized Beidou four-frequency ionosphere-free dual combination positioning model to obtain high-precision receiver position coordinates.

[0112] Example 3

[0113] See also Fig. 9 , Fig. 9 This is a schematic diagram of the structure of a Beidou quad-frequency precise point positioning device based on satellite-based augmentation service disclosed in an embodiment of the present invention. Fig. 9 The described device can be applied to satellite positioning, such as precise point positioning, etc., and the embodiments of the present invention do not limit this.

[0114] like Fig. 9As shown, the device may include a processor and a memory, wherein the memory stores computer instructions, and the processor is used to execute the computer instructions stored in the memory. When the computer instructions are executed by the processor, the electronic device implements the steps of the method described in the above embodiment and can achieve the technical effect consistent with the above method.

[0115] The memory may include computer system readable media in the form of volatile memory, such as random access memory (RAM) and / or cache memory. The device may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the memory may be used to read and write non-removable, non-volatile magnetic media (commonly referred to as a "hard drive"). A program / utility having a set (at least one) of program modules may be stored in, for example, the memory, such program modules including but not limited to an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include the implementation of a network environment. The program modules typically perform the functions and / or methods in the embodiments described herein.

[0116] The processor executes various functional applications and data processing by running the programs stored in the memory, such as implementing the method provided in Embodiment 1 of the present invention.

[0117] Example 4

[0118] Embodiment 4 of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the method described in the above embodiment are implemented and the technical effect consistent with the above method can be achieved.

[0119] The computer storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, a device or a device or used in combination with it.

[0120] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0121] The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0122] Computer program code for performing the operation of the present invention may be written in one or more programming languages ​​or combinations thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer through any type of network including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0123] Of course, the storage medium containing computer executable instructions provided by an embodiment of the present invention, whose computer executable instructions are not limited to the above method operations, can also execute related operations in the method provided by any embodiment of the present invention.

[0124] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A Beidou quad-frequency precise point positioning method based on satellite-based augmentation service, characterized in that: include: Signal reception and decoding: Receive the four positioning frequency band signals of Beidou B1I, B3I, B1C and B2a, as well as PPP-B2b signals and broadcast ephemeris in real time, decode all received signals, and extract the original observation data and broadcast ephemeris information; Data matching: Match the correction information obtained by decoding the PPP-B2b signal with the corresponding information in the broadcast ephemeris, including matching the correction information type based on IOD SSR, matching the clock error of IODP with the orbit correction information, matching the correction number of IODCorr with the satellite PRN, and matching the correction information based on IODN with the broadcast ephemeris; Precision orbit acquisition: Apply the orbit correction information in the PPP-B2b signal to the broadcast ephemeris orbit to obtain precise real-time satellite orbit coordinates; Precise clock error acquisition: Apply the clock error correction information in the PPP-B2b signal to the broadcast ephemeris clock error to obtain accurate real-time satellite clock error; Model construction: Based on the extracted original observation data, according to the frequency combinations of B1I / B3I and B1C / B2a, ionosphere-free combined observation equations are constructed respectively to eliminate the first-order delay of the ionosphere. The two ionosphere-free combined observation equations are used as a Beidou four-frequency ionosphere-free dual combination positioning model. Precise orbit / clock correction: Taking the calculated real-time satellite orbit coordinates and real-time satellite clock errors as known values, the orbit and clock error parameters in the Beidou four-frequency ionosphere-free dual-combination positioning model are corrected to obtain the corrected Beidou four-frequency ionosphere-free dual-combination positioning model; Unification of receiver clock errors: Taking the clock error in the ionosphere-free combined observation equation of B1I / B3I as the benchmark, unify the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a, so as to ensure the consistency of the receiver clock error in the combined observation values ​​of different frequency bands. Use the BeiDou-3 DCB correction information in the PPP-B2b signal to linearize the corrected BeiDou four-frequency ionosphere-free dual combination positioning model. Positioning solution: The Kalman filter algorithm is used to solve the linearized Beidou four-frequency ionosphere-free dual-combination positioning model to obtain high-precision receiver position coordinates.

2. The Beidou quad-frequency precise point positioning method based on satellite-based augmentation service according to claim 1, characterized in that: By checking the IOD SSR, it is confirmed whether the correction information in the received PPP-B2b signal is generated by the same system configuration, so as to achieve the correction information type matching; Use IODP to match satellite clock correction information with the corresponding mask information; At the same time, the satellite orbit correction number is directly matched with the corresponding satellite number through the mask information to ensure that the orbit and clock correction numbers can be correctly associated with their respective satellites, thereby achieving matching of clock and orbit correction information.

3. The Beidou quad-frequency precise point positioning method based on satellite-based augmentation service according to claim 1, characterized in that: IOD Corr is used to further accurately match the clock correction number and orbit correction number with their corresponding satellite PRN numbers, thereby achieving matching between the correction number and the satellite PRN; By checking the IODN in the PPP-B2b correction information and the IODC parameters in the broadcast ephemeris, the PPP-B2b correction information is matched with the broadcast ephemeris, so that the correction information and the broadcast ephemeris are matched.

4. The Beidou quad-frequency precise point positioning method based on satellite-based augmentation service according to claim 1, characterized in that: Apply the orbit correction information in the PPP-B2b signal to the broadcast ephemeris orbit to obtain accurate real-time satellite orbit coordinates, including: Calculate the real-time satellite orbit coordinates as follows: In the formula, are the radial, tangential and normal corrections for the PPP-B2b orbit; are the radial, tangential and normal direction unit vectors respectively; and are the position and velocity vectors in the Earth-centered Earth-fixed coordinate system respectively; Real-time precise satellites obtained after PPP-B2b orbit correction for broadcast ephemeris; is the satellite position vector calculated from the broadcast ephemeris.

5. The Beidou quad-frequency precise point positioning method based on satellite-based augmentation service according to claim 1, characterized in that: Apply the clock correction information in the PPP-B2b signal to the broadcast ephemeris clock error to obtain accurate real-time satellite clock errors, including: Calculate the real-time satellite clock error. The expression is as follows: In the formula, Indicates the corrected real-time precise clock error; represents the broadcast ephemeris satellite clock error; d clk represents the PPP-B2b clock correction; c represents the speed of light.

6. The Beidou quad-frequency precise point positioning method based on satellite-based augmentation service according to claim 1, characterized in that: Based on the extracted original observation data, according to the frequency combinations of B1I / B3I and B1C / B2a, ionosphere-free combined observation equations are constructed to eliminate the first-order delay of the ionosphere. The two ionosphere-free combined observation equations are used as the Beidou four-frequency ionosphere-free dual combination positioning model, including: Define B1I as the first frequency, B3I as the second frequency, B1C as the third frequency, and B2a as the fourth frequency; Construct the Beidou quad-frequency ionosphere-free dual-combination positioning model, the expression is as follows: in: Where s and r are GNSS satellite and user receiver respectively; IF 12 The ionospheric-free combination of frequencies 1 and 2; IF 34 An ionospheric-free combination of bands 3 and 4; are the ionospheric-free pseudorange observations of frequencies 1 and 2 between satellite s and receiver r; is the ionospheric-free pseudorange observation value of frequencies 3 and 4 between satellite s and receiver r; are the ionospheric-free carrier observations of frequencies 1 and 2 between satellite s and the receiver; are the ionospheric-free carrier observations of frequencies 3 and 4 between satellite s and the receiver; is the geometric distance between the receiver and the satellite; is the ionospheric-free combined clock error of frequencies 1 and 2 at the receiver; is the ionospheric-free combined clock error of frequencies 3 and 4 at the receiver, is the clock difference between the receiver and the satellite; is the tropospheric delay between the GNSS satellite s and the user receiver r; It is the B3I reference frequency pseudorange hardware delay on the satellite side; The ionospheric pseudorange hardware delay is free for satellite s frequencies 1 and 2; Ionospheric pseudorange hardware delay for satellite s frequencies 3 and 4; is the ionospheric-free float resolution of the frequency combination 1 and 2 in satellite s and receiver r, is the ionospheric-free float resolution of the frequency combination 3 and 4 in satellite s and receiver r; is the ionospheric-free wavelength of the combination of frequencies 1 and 2; is the ionospheric-free wavelength for the combination of frequencies 3 and 4; and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier for frequencies 1 and 2 of satellite s and receiver r, respectively; and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier frequencies 3 and 4 for satellite s and receiver r, respectively; dt r is the receiver clock error; is the pseudorange hardware delay of the ionosphere-free combination of receiver r frequencies 1 and 2; is the pseudorange hardware delay of the ionosphere-free combination of receiver r frequencies 3 and 4; is the ionospheric-free combined ambiguity of the frequency 1 and 2 combination of satellite s and receiver r; is the ionospheric-free combined ambiguity for the combination of frequencies 3 and 4 of satellite s and receiver r; There is no ionospheric carrier hardware delay for frequencies 1 and 2 at the receiver end; No ionospheric carrier hardware delay for receiver frequencies 3 and 4; Indicates the hardware delay of the ionosphere-free combined carrier of satellite frequency 1 and 2; Indicates the hardware delay of the ionosphere-free combined carrier of satellite frequencies 3 and 4.

7. The Beidou quad-frequency precise point positioning method based on satellite-based augmentation service according to claim 1, characterized in that: Taking the clock error in the ionosphere-free combined observation equation of B1I / B3I as the benchmark, the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a is unified to ensure the consistency of the receiver clock error in the combined observation values ​​of different frequency bands. The BeiDou-3 DCB correction information in the PPP-B2b signal is used to linearize the corrected BeiDou four-frequency ionosphere-free dual combination positioning model, including: Taking the clock error in the ionosphere-free combined observation equation of B1I / B3I as the benchmark, the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a is unified, and the linearized equation of the ionosphere-free combined pseudorange and carrier observation is obtained as follows: In the formula, represents the linearized ionospheric-free pseudorange observation value of the frequency combination 1 and 2 between satellites s and r, represents the linearized ionospheric-free pseudorange observation value of the frequency combination 3 and 4 between satellites s and r, represents the linearized carrier-free ionosphere-free observation value of the frequency combination 1 and 2 between satellites s and r, represents the linearized carrier-free ionosphere observation value of the frequency combination 3 and 4 between satellites s and r, and dX represents the position parameter to be estimated; is the coefficient of the unknown position parameter dX between satellites s and r after linearization; It represents the ionospheric-free combined clock error of frequencies 1 and 2 at the receiver end. is the tropospheric projection function of satellites s and r, T is the tropospheric delay; and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier frequencies 1 and 2 for satellite s and receiver r, respectively, and are the observation noises corresponding to the ionosphere-free combined pseudorange and carrier frequencies 3 and 4 for satellite s and receiver r, respectively; other symbols are as follows: Where, f1, f2, f3, and f4 represent the frequency values ​​of frequencies 1, 2, 3, and 4 respectively; Respectively represent the code deviation between satellite frequency points 1, 2, 3, 4 and the reference frequency B3I; DCB r,12 Indicates the code deviation of frequency 1 and frequency 2 at the receiver; Indicates the ionosphere-free receiver clock error between frequencies 1 and 2 and the ionosphere-free combined receiver clock error between frequencies 3 and 4, DCB r,34 Indicates the code deviation of frequency 3 and frequency 4 at the receiver end; Indicates that IF 12 As the benchmark, the reconstructed ambiguity parameters are obtained.

8. A Beidou quad-frequency precise point positioning system based on satellite-based augmentation service, characterized in that: include: The signal receiving and decoding module is used to receive the Beidou B1I, B3I, B1C and B2a positioning frequency band signals, as well as the PPP-B2b signal and broadcast ephemeris in real time, decode all received signals, and extract the original observation data and broadcast ephemeris information; Data matching module, used to match the correction information obtained by decoding the PPP-B2b signal with the corresponding information in the broadcast ephemeris, including matching the correction information type based on IOD SSR, matching the clock error of IODP with the orbit correction information, matching the correction number of IOD Corr with the satellite PRN, and matching the correction information based on IODN with the broadcast ephemeris; Precision orbit acquisition module, used to apply the orbit correction information in the PPP-B2b signal to the broadcast ephemeris orbit to obtain accurate real-time satellite orbit coordinates; The precise clock error acquisition module is used to apply the clock error correction information in the PPP-B2b signal to the broadcast ephemeris clock error to obtain the precise real-time satellite clock error; The model building module is used to construct ionosphere-free combined observation equations based on the extracted original observation data and the frequency combinations of B1I / B3I and B1C / B2a to eliminate the first-order delay of the ionosphere. The two ionosphere-free combined observation equations are used as a Beidou four-frequency ionosphere-free dual-combination positioning model. The precise orbit / clock correction module is used to take the calculated real-time satellite orbit coordinates and real-time satellite clock errors as known values, and correct the orbit and clock error parameters in the Beidou four-frequency ionosphere-free dual-combination positioning model to obtain the corrected Beidou four-frequency ionosphere-free dual-combination positioning model; The receiver clock error unification module is used to unify the receiver clock error in the ionosphere-free combined observation equation of B1C / B2a based on the clock error in the ionosphere-free combined observation equation of B1I / B3I, so as to ensure the consistency of the receiver clock error in the combined observation values ​​of different frequency bands, and use the Beidou-3 DCB correction information in the PPP-B2b signal to linearize the corrected Beidou four-frequency ionosphere-free dual combination positioning model; The positioning solution module is used to use the Kalman filter algorithm to solve the linearized Beidou four-frequency ionosphere-free dual combination positioning model to obtain high-precision receiver position coordinates.

9. A Beidou quad-frequency precise point positioning device based on satellite-based augmentation service, characterized in that: The electronic device comprises a processor and a memory, wherein the memory stores computer instructions, and the processor is used to execute the computer instructions stored in the memory. When the computer instructions are executed by the processor, the electronic device implements the steps of the Beidou quad-frequency precise point positioning method based on satellite-based augmented service as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the Beidou quad-frequency precise point positioning method based on satellite-based augmented service as described in any one of claims 1 to 7.

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