Low earth orbit satellite navigation augmentation and ground-based CORS coordination system

Abstract

The application discloses a low-orbit satellite navigation enhancement and ground CORS cooperative system and relates to the technical field of satellite navigation positioning, which comprises a space segment, a ground segment and a user segment; the space segment comprises a low-orbit satellite and is used for broadcasting navigation enhancement signals; the ground segment comprises an enhanced CORS network and a star-ground cooperative control center; each ground reference station simultaneously receives GNSS signals and navigation enhancement signals and generates observation data; the star-ground cooperative control center performs precise orbit determination based on low-orbit satellite downlink data and observation data, and uploads star-ground calculation results to the low-orbit satellite to update the generation parameters of the navigation enhancement signals; the user segment comprises a hybrid enhancement receiver, which is used for receiving GNSS signals, navigation enhancement signals and differential data and performing multi-source fusion positioning calculation. The application can improve the low-orbit satellite orbit determination precision, shorten the user initialization time, expand the service coverage, reduce the system construction cost and enhance the integrity guarantee capability.

Description

Technical Field

[0001] This invention relates to the field of satellite navigation and positioning technology, and in particular to a low-orbit satellite navigation enhancement and ground CORS collaborative system. Background Technology

[0002] Low Earth Orbit (LEO) satellite navigation augmentation systems utilize a constellation of LEO satellites at altitudes of approximately 800-1200 kilometers, carrying navigation augmentation payloads. By broadcasting enhanced information such as precise orbits, clock corrections, and ionospheric models to ground users, they achieve high-precision navigation and positioning. Compared to traditional medium- and high-orbit navigation satellites, LEO satellites possess unique advantages such as high signal strength, rapid geometric changes, and excellent global coverage. They effectively improve user convergence speed and expand service range, and are considered a crucial development direction for next-generation high-precision navigation augmentation. The Continuously Operating Reference Stations (CORS) network is a ground infrastructure composed of densely distributed high-precision Global Navigation Satellite System (GNSS) reference stations. Each station transmits observation data to a processing center via real-time data communication links. Using multi-reference station data, a regional error model is established, generating Virtual Reference Station (VRS) differential data to provide users with centimeter-level real-time kinematic (RTK) positioning services. Ground-based CORS network technology is mature and highly accurate, but it is limited by the construction cost of ground stations and geographical conditions, resulting in coverage blind spots in areas such as oceans and remote mountainous regions, and the user initialization time is relatively long.

[0003] Existing technologies employ low-Earth orbit (LEO) satellite constellations carrying navigation enhancement payloads. These payloads receive navigation signals from systems such as the BeiDou Navigation Satellite System (BDS) or Global Positioning System (GPS) via onboard global navigation satellite system (GNSS) receivers. The satellites autonomously determine their orbits and generate enhancement information. They then broadcast precise orbit and clock correction information to ground users via L-band or B3C frequency bands. Only a small number of ground monitoring stations are deployed for satellite control and status monitoring. User receivers receive the enhancement signals broadcast by the LEO satellites to achieve rapid and precise positioning. Specifically, existing technologies utilize a densely distributed ground-based CORS network. Each reference station is equipped with a high-precision GNSS receiver. Observational data is transmitted in real-time to a network-based real-time dynamic positioning processing center via fiber optic or wireless networks. The central server uses the observation data from multiple reference stations to establish a regional error model, generating VRS differential data, which is then broadcast to users via mobile communication networks. User receivers receive this differential data to achieve centimeter-level real-time dynamic positioning. Existing technologies also propose a simple combination of low-Earth orbit (LEO) satellite navigation enhancement and ground-based CORS networks. LEO satellites and ground-based CORS operate independently, with LEO satellites serving only as supplementary broadcasting channels for ground-based CORS data, or ground-based CORS serving only as monitoring stations for LEO satellites. There is no deep integration mechanism between the two, the data flow is singular, and collaborative optimization is not achieved.

[0004] The aforementioned existing technologies each have objective drawbacks. In low-Earth orbit (LEO) satellite navigation augmentation systems, LEO satellites rely on onboard autonomous orbit determination or a small number of ground monitoring stations for orbit determination. The orbit determination accuracy is typically at the meter to decimeter level, which is insufficient to meet the precise ephemeris requirements of centimeter-level navigation augmentation services. This limits user positioning accuracy, and when using LEO augmentation alone, users still need several minutes to complete carrier phase ambiguity convergence, failing to meet the second-level convergence requirements of autonomous driving and drone control. In terrestrial CORS networks, the terrestrial CORS network relies on dense ground station construction, which is difficult to deploy in remote areas such as oceans, mountains, and deserts, resulting in coverage blind spots and the inability to achieve seamless, high-precision positioning services across the entire region. Furthermore, the network's real-time dynamic positioning initialization time typically takes tens of seconds to several minutes, significantly longer, especially during periods of ionospheric activity or with long baselines, impacting the real-time application experience. In simple combined satellite-to-ground augmentation systems, the coverage area of ​​low-Earth orbit (LEO) satellites and ground-based CORS is not optimized in coordination during their transit, resulting in overlapping or gaps in coverage. The rapid geometrical changes of LEO satellites are not fully utilized, and the high-precision observation data from ground-based CORS is not effectively fed back into LEO orbit determination. Furthermore, existing technologies rely on the integrity monitoring of a single system, which creates monitoring blind spots. When LEO satellite orbital anomalies or ground-based CORS data anomalies occur, timely identification and early warning are not possible, making it difficult to meet the high-safety requirements of scenarios such as aviation and autonomous driving.

[0005] In summary, current low-Earth orbit satellite navigation augmentation and terrestrial CORS networks, operating independently or in a simple combination mode, suffer from problems such as limited orbit determination accuracy of low-Earth orbit satellites, long user convergence time, blind spots in terrestrial network coverage, lack of coordinated optimization of satellite and ground resources, and insufficient integrity monitoring capabilities. There is an urgent need for a technical solution that can achieve deep integration and coordinated optimization of the two. Summary of the Invention

[0006] The technical problem this invention aims to solve is to address the shortcomings of existing technologies, specifically the independent operation and lack of deep integration between low-Earth orbit (LEO) satellite navigation augmentation systems and terrestrial CORS networks. This results in limited LEO satellite orbit determination accuracy, long user convergence times, blind spots in terrestrial network coverage, and a lack of coordinated optimization of satellite and ground resources. The invention provides a collaborative system between LEO satellite navigation augmentation and terrestrial CORS, as detailed below: 1) In a first aspect, the present invention provides a low-orbit satellite navigation enhancement and ground CORS cooperative system, the specific technical solution of which includes: a space segment, a ground segment and a user segment; The space segment includes low-Earth orbit satellites, which carry navigation enhancement payloads for broadcasting navigation enhancement signals; The ground segment includes an enhanced CORS network and a satellite-ground coordinated control center. Each ground reference station in the enhanced CORS network receives GNSS signals and the navigation enhancement signal, and transmits the CORS observation data generated by each ground reference station to the satellite-ground coordinated control center in real time. The satellite-ground coordinated control center receives downlink data from the low-Earth orbit satellite and the CORS observation data, performs precise orbit determination calculations on the low-Earth orbit satellite based on the downlink data and CORS observation data, obtains the satellite-ground calculation results for the low-Earth orbit satellite, and uplinks the satellite-ground calculation results to the low-Earth orbit satellite to update the generation parameters of the navigation enhancement signal. The user segment includes a hybrid augmentation receiver for receiving the GNSS signal, the navigation augmentation signal, and differential data provided by the ground segment, and performing multi-source fusion positioning calculation based on the GNSS signal, the navigation augmentation signal, and the differential data.

[0007] The beneficial effects of the low-Earth orbit satellite navigation enhancement and ground-based CORS coordinated system provided by this invention are as follows: The ground-based CORS network simultaneously serves as a precision tracking station for low-Earth orbit (LEO) satellites, utilizing high-precision CORS observation data to improve LEO satellite orbit determination accuracy from meter-level to centimeter-level. A unified processing system of downlink and CORS observation data, integrated with a space-ground collaborative control center, is used to inject uplink data into LEO satellites to update the generation parameters of navigation augmentation signals. This forms a positive feedback loop of centralized ground-based calculation, uplink product injection, and satellite augmentation signal broadcasting, avoiding complex onboard processing payloads and reducing satellite payload complexity and system construction costs. A hybrid augmentation receiver utilizes GNSS signals, navigation augmentation signals, and differential data for multi-source fusion positioning calculations, achieving rapid initialization within the coverage area of ​​the enhanced CORS network. In coverage blind spots, it maintains positioning services based on the global coverage characteristics of LEO satellites. This effectively solves the technical problems of limited LEO satellite orbit determination accuracy, long user convergence time, blind spots in ground network coverage, and lack of coordinated optimization of space-ground resources in existing technologies.

[0008] Based on the above solution, the present invention can be further improved as follows.

[0009] Furthermore, each ground reference station in the enhanced CORS network is equipped with a low-orbit signal receiving channel on the basis of a receiver with multi-frequency GNSS signal receiving function, for receiving the GNSS signal and the navigation enhancement signal; The satellite-ground collaborative control center includes a low-orbit signal monitoring subsystem, a network RTK processing center, and a satellite-ground collaborative processing unit. The low-orbit signal monitoring subsystem is used to process the CORS observation data transmitted from various ground reference stations and monitor signal quality indicators. The network RTK processing center is used to generate VRS differential data based on the CORS observation data and provide network RTK services; The satellite-ground collaborative processing unit is used to perform precise orbit determination calculations on the low-orbit satellite based on the downlink data and the CORS observation data, and obtain the satellite-ground calculation results.

[0010] Furthermore, the satellite-ground collaborative control center is also used to determine the regional results of satellite-ground joint coverage based on the transit trajectory of the low-orbit satellite and the coverage of the enhanced CORS network; determine the positioning accuracy requirements based on user positioning information and application scenarios; and select a positioning service mode based on the regional results and the positioning accuracy requirements, wherein the positioning service modes include urban dense area mode, suburban transition zone mode and remote area mode. In the urban dense area mode, the network RTK is the primary positioning service, and the navigation enhancement signal is used to assist in accelerating carrier phase ambiguity fixation to shorten the initialization time. In the suburban transition zone mode, the navigation enhancement signal is used as the primary positioning service, and the enhanced CORS network is used to provide the satellite-to-ground solution results to update the generation parameters of the navigation enhancement signal; In the remote area mode, where there is no enhanced CORS network coverage, positioning services are provided using the navigation enhancement signals based on the global coverage characteristics of low-Earth orbit satellites.

[0011] Furthermore, the space-ground collaborative control center is also used to combine the onboard GNSS observation data in the downlink data with the GNSS observation data and low-orbit satellite signal observation data in the CORS observation data to estimate the regional ionospheric delay gradient in real time, and to use the low-orbit satellite as a mobile reference station to form a short baseline combination with the ground reference station in order to achieve carrier phase ambiguity fixation in a single epoch.

[0012] Furthermore, the space-ground collaborative control center is also used to perform joint space-ground integrity monitoring, which includes autonomous monitoring of the space segment, independent monitoring of the ground segment, and cross-verification monitoring between space and ground. The autonomous monitoring of the space segment includes: monitoring the status of the onboard multi-frequency GNSS receiver, the frequency stability of the atomic clock, and the status of the navigation enhancement signal generation and transmission link through the low-Earth orbit satellite; The independent ground segment monitoring includes: monitoring the signal quality of the navigation enhancement signal through the enhanced CORS network, and / or comparing the navigation enhancement signal received by various ground reference stations through the enhanced CORS network, and / or comparing the satellite ephemeris clock difference in the downlink data with the ephemeris clock difference in the satellite-ground co-operation control center; The satellite-to-ground cross-verification monitoring includes triggering an integrity alarm when the difference between the satellite ephemeris clock difference in the downlink data and the ephemeris clock difference in the satellite-to-ground solution exceeds a threshold.

[0013] Furthermore, the navigation enhancement payload includes: a spaceborne multi-frequency GNSS receiver, an inter-satellite link unit, a navigation enhancement signal generation unit, and a data injection receiving module; The onboard multi-frequency GNSS receiver is used to receive GNSS signals, for onboard autonomous orbit determination, and to provide the basic data for generating the navigation enhancement signals. The inter-satellite link unit is used to enable communication and time synchronization between satellites within the low-Earth orbit constellation; The navigation enhancement signal generation unit is used to generate and broadcast the navigation enhancement signal; The data injection receiving module is used to receive the satellite-ground calculation results generated by the satellite-ground cooperative control center, so as to update the generation parameters of the navigation enhancement signal.

[0014] Furthermore, the hybrid enhancement receiver includes a multi-mode receiving module and a cooperative positioning solution engine; The multimode receiving module is used to receive the GNSS signal, the navigation enhancement signal, and the differential data; The collaborative positioning solution engine is used to perform multi-source fusion positioning solution and adaptively selects the solution mode according to the positioning service mode.

[0015] 2) In a second aspect, the present invention also provides a method for low-Earth orbit satellite navigation enhancement and ground-based CORS cooperative positioning, applicable to any of the low-Earth orbit satellite navigation enhancement and ground-based CORS cooperative systems described in the first aspect. The specific technical solution is as follows: The system receives GNSS signals and navigation enhancement signals broadcast by low-orbit satellites through various ground reference stations, and generates CORS observation data which is then transmitted to the space-ground collaborative control center in real time. The satellite-ground collaborative control center receives downlink data from the low-Earth orbit satellite and CORS observation data; performs precise orbit determination calculations on the low-Earth orbit satellite based on the downlink data and CORS observation data to obtain the satellite-ground calculation results; and injects the satellite-ground calculation results uplink into the low-Earth orbit satellite. The low-orbit satellite updates the generation parameters of the navigation enhancement signal based on the satellite-to-ground calculation results, and broadcasts the updated navigation enhancement signal. The GNSS signal, the navigation enhancement signal, and the differential data are received by a hybrid enhancement receiver, and multi-source fusion positioning calculation is performed based on the GNSS signal, the navigation enhancement signal, and the differential data.

[0016] 3) In a third aspect, the present invention also provides a computer device, the computer device including a processor coupled to a memory, the memory storing at least one computer program, the at least one computer program being loaded and executed by the processor to enable the computer device to implement any of the above methods.

[0017] 4) In a fourth aspect, the present invention also provides a computer-readable storage medium storing at least one computer program, which is loaded and executed by a processor to enable a computer to implement any of the above methods.

[0018] It should be noted that the beneficial effects of the technical solutions of the second to fourth aspects of the present invention and their corresponding possible implementations can be found in the above description of the technical effects of the first aspect and its corresponding possible implementations, and will not be repeated here. Attached Figure Description

[0019] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the composition structure of a low-orbit satellite navigation enhancement and ground CORS collaborative system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of ground calculation-uplink injection closed-loop optimization of a low-orbit satellite navigation enhancement and ground CORS collaborative system according to an embodiment of the present invention; Figure 3 This is a flowchart illustrating the steps of a low-orbit satellite navigation enhancement and ground CORS cooperative positioning method according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0021] like Figure 1 As shown in the figure, a low-orbit satellite navigation enhancement and ground CORS cooperative system according to an embodiment of the present invention includes: a space segment, a ground segment, and a user segment.

[0022] (1) The space segment includes low-orbit satellites.

[0023] Low Earth Orbit (LEO) satellites refer to artificial satellites with an orbital altitude of approximately 800-1200 kilometers, characterized by high signal strength, rapid geometric changes, and good global coverage. In this embodiment, the LEO satellite carries a navigation enhancement payload, which, in coordination with the ground-based CORS network, enables high-precision navigation and positioning enhancement services. As another implementation of this embodiment, regarding the LEO satellite constellation configuration, the number of satellites in this constellation can be flexibly adjusted according to service requirements, ranging from a few to hundreds, all of which can achieve the satellite-ground coordination function described in this solution. Increasing or decreasing the number of satellites does not affect the implementation of the core architecture of this solution.

[0024] The navigation enhancement payload is used to receive signals from the Global Navigation Satellite System (GNSS) and broadcast navigation enhancement signals (such as... Figure 2 (As shown in the diagram, "signal broadcasting"). Navigation enhancement signals refer to the enhanced information broadcast by low-Earth orbit satellites to ground users via the L-band or B3C band, including data such as precise orbits, clock corrections, and ionospheric models.

[0025] In this implementation, the low-Earth orbit satellite does not directly receive observation data from the CORS network, nor does it perform on-board collaborative orbit determination calculations. Instead, it receives precision products pre-processed on the ground through a standard data interface, simplifying the on-board architecture and improving reliability.

[0026] (2) The ground segment includes an enhanced CORS network and a satellite-ground coordinated control center.

[0027] Continuously Operating Reference Stations (CORS) refer to GNSS reference stations that operate continuously at fixed ground locations for extended periods. Equipped with high-precision GNSS receivers, they are capable of continuously receiving GNSS satellite signals around the clock and transmitting observation data to a data processing center in real time via a data communication link. In this embodiment, the ground reference station refers to a GNSS reference station that operates continuously at a fixed ground location for extended periods. As another implementation of this embodiment, for an enhanced CORS network architecture, the CORS network is not limited to national or provincial-level CORS networks. It can also employ industry-specific CORS networks (such as power and transportation industry networks), enterprise-built CORS networks, or international IGS reference station networks. The network scale can be flexibly configured from a single station to hundreds of stations, all capable of achieving the ground reference station functions described in this solution.

[0028] An enhanced CORS network consists of multiple ground reference stations (such as...) Figure 1 The system consists of ground reference stations (such as "CORS1", "CORS2", etc.) that simultaneously receive GNSS signals and navigation enhancement signals broadcast by low-orbit satellites, and transmit the CORS observation data generated by each ground reference station to the space-ground collaborative control center (e.g., Figure 2 The term "CORS observations" is shown in the image. CORS observation data refers to the collective term for GNSS observation data (including pseudorange, carrier phase, Doppler, etc.) collected by various ground reference stations, as well as low-Earth orbit satellite signal observation data (including signal power, carrier-to-noise ratio, Doppler shift, etc.).

[0029] In this embodiment, the functionality of the traditional CORS network is extended by constructing a space-ground collaborative control center as the core processing node of the system. Specifically, the space-ground collaborative control center is deployed on the ground to receive downlink data from low-Earth orbit (LEO) satellites and CORS observation data. LEO satellite downlink data refers to data broadcast to the ground by LEO satellites via the space-ground link, including onboard GNSS observation data, satellite ephemeris, and satellite clock bias. Figure 2 As shown, the space-ground collaborative control center performs precise orbit determination calculations for low-Earth orbit satellites based on downlink data and CORS observation data (e.g., Figure 2The "ground-based calculation" shown in the diagram obtains the satellite-to-ground calculation results for the low-Earth orbit (LEO) satellite. These results refer to the precise ephemeris and clock bias data of the LEO satellite, calculated by the ground-based satellite-to-ground collaborative control center by integrating multiple observation data, achieving an accuracy down to the centimeter level. The satellite-to-ground collaborative control center injects the satellite-to-ground calculation results into the LEO satellite (e.g., via the Ka-band uplink of the ground reference station) through the ground reference station. Figure 2 The "uplink injection" shown in the diagram updates the generation parameters of the navigation enhancement signal, ensuring that the accuracy of the enhancement information broadcast by the low-Earth orbit satellite is consistent with the ground calculation results, thereby achieving closed-loop optimization of centralized ground calculation and product uplink injection. As another implementation of this embodiment, regarding the communication link between the satellite and the ground, in this implementation, the data interaction between the ground reference station and the low-Earth orbit satellite can be achieved using the S-band, X-band, or laser communication link in addition to the Ka band, thus realizing the function described in this solution. As another implementation of this embodiment, regarding the precise orbit determination calculation process, in this implementation, the precise orbit determination calculation performed by the satellite-ground collaborative control center is not limited to the Kalman filter algorithm; it can also use least squares estimation, particle filtering, or other state estimation methods. Precise point positioning (PPP) or relative positioning technology can be used to achieve low-Earth orbit satellite orbit determination. A cloud computing or edge computing architecture can be used to deploy the satellite-ground collaborative control center, thus also realizing the satellite-ground collaborative precise orbit determination function described in this solution.

[0030] (3) The user segment includes a hybrid enhancement receiver.

[0031] The hybrid augmentation receiver receives GNSS signals, navigation augmentation signals broadcast by low-Earth orbit satellites, and differential data provided by the ground segment. It then performs multi-source fusion positioning calculations based on the received GNSS signals, navigation augmentation signals, and differential data. The differential data refers to the virtual reference station (VRS) differential data generated by the ground segment through a network-based real-time kinematic (RTK) processing center.

[0032] The corresponding beneficial effects are as follows: This implementation method sets up ground reference stations in the enhanced CORS network to simultaneously receive GNSS signals and navigation enhancement signals broadcast by low-Earth orbit (LEO) satellites, and transmits CORS observation data to the space-ground collaborative control center in real time. This allows the ground CORS network to simultaneously serve as a precision tracking station for LEO satellites, achieving effective feedback from high-precision ground observation data to LEO satellite orbit determination. The space-ground collaborative control center performs precise orbit determination calculations based on LEO satellite downlink data and CORS observation data to obtain centimeter-level precision space-ground calculation results, which are then uplinked to the LEO satellites to update navigation enhancement signals. The generation parameters of the strong signal form a positive feedback loop between ground calculation and satellite broadcasting, avoiding complex on-board processing payloads and reducing satellite payload complexity and system construction costs. By using a hybrid augmentation receiver to simultaneously utilize GNSS signals, LEO satellite augmentation signals, and ground differential data for multi-source fusion calculation, rapid initialization is achieved in CORS network coverage areas, and positioning services are maintained in coverage blind areas by relying on the global coverage characteristics of LEO satellites. This effectively solves the technical problems of limited LEO satellite orbit determination accuracy, long user convergence time, blind areas in ground network coverage, and lack of coordinated optimization of satellite and ground resources in existing technologies.

[0033] As another specific implementation, in this implementation, based on the specific structure of the enhanced CORS network and the space-ground coordinated control center, each ground reference station in the enhanced CORS network adds a low-orbit signal receiving channel to the receiver with multi-frequency GNSS signal receiving function, for receiving GNSS signals and navigation enhancement signals.

[0034] The space-ground collaborative control center includes a low-orbit signal monitoring subsystem, a network RTK processing center, and a space-ground collaborative processing unit.

[0035] The Low Earth Orbit (LEO) signal monitoring subsystem processes CORS observation data transmitted from various ground reference stations and monitors signal quality indicators. Specifically, the LEO signal monitoring subsystem processes LEO satellite signal observation data from the CORS observation data transmitted from various ground reference stations, monitors signal quality indicators such as signal power, carrier-to-noise ratio, and Doppler shift, and evaluates the performance of LEO augmentation services.

[0036] The network RTK processing center is used to generate VRS differential data based on GNSS observation data in CORS observation data, establish regional ionospheric / tropospheric error models, and provide network RTK services.

[0037] The space-ground collaborative processing unit is used to perform precise orbit determination calculations for low-Earth orbit (LEO) satellites based on downlink data and CORS observation data, obtaining the space-ground calculation results. Specifically, the space-ground collaborative processing unit is used to fuse onboard GNSS observation data from LEO satellite downlink data and GNSS observation data from CORS observation data, and to estimate the precise ephemeris and clock bias data of LEO satellites in real time, thereby obtaining the space-ground calculation results.

[0038] The corresponding beneficial effects are as follows: This implementation achieves "dual-use" functionality by adding a low-Earth orbit (LEO) signal receiving channel to the ground reference station, enabling the enhanced CORS network to simultaneously possess LEO satellite tracking and monitoring capabilities without the need for an additional dedicated LEO monitoring station, significantly reducing system construction costs; the LEO signal monitoring subsystem monitors the quality of enhanced LEO signals in real time, providing data support for service performance evaluation; the network RTK processing center generates VRS differential data, ensuring the traditional network RTK service capabilities; and the satellite-ground collaborative processing unit integrates onboard GNSS observation data and GNSS observation data obtained from the ground reference station, improving the LEO satellite orbit determination accuracy from the meter level to the centimeter level, significantly enhancing the quality of enhanced services.

[0039] As another specific implementation method, regarding dynamic resource scheduling and positioning service mode switching, in this implementation method, the space-ground collaborative control center is also used to perform dynamic resource scheduling. Specifically, the space-ground collaborative control center determines the regional results of joint space-ground coverage based on the transit trajectory of low-orbit satellites and the coverage area of ​​the enhanced CORS network; determines the positioning accuracy requirements based on user positioning information and application scenarios; and selects the positioning service mode based on the regional results and positioning accuracy requirements.

[0040] Specifically, based on the transit trajectories of low-Earth orbit (LEO) satellites and the coverage area of ​​the enhanced CORS network, the ground coverage trajectories of LEO satellites are predicted within a certain future timeframe. Combined with the distribution of the enhanced CORS network, the spatiotemporal intersection and difference regions of the joint satellite-ground coverage are calculated to determine the regional results of the joint satellite-ground coverage. The satellite-ground collaborative control center generates a user distribution heatmap using user access data and location reporting information. Combining this with application scenarios (such as autonomous driving, drones, and surveying), it identifies the positioning accuracy requirements (centimeter / decimeter level) and convergence time requirements (second / minute level) for different regions, thus determining the positioning accuracy requirements. As another implementation of this embodiment, regarding dynamic resource scheduling, in this implementation, the dynamic resource scheduling performed by the satellite-ground collaborative control center is not limited to the location service mode switching based on the "regional results of joint satellite-ground coverage" described above. It can also be based on real-time user requests, network load conditions, or quality of service (QoS) requirements. Machine learning algorithms can be used to predict user distribution and optimize resource allocation, thus achieving the dynamic resource scheduling function described in this solution.

[0041] Based on the regional results and positioning accuracy requirements, the satellite-ground collaborative control center automatically selects the positioning service mode, which includes urban densely populated area mode, suburban transition zone mode, and remote area mode. The specific implementation of the positioning service mode is as follows: In densely populated urban areas, an enhanced CORS network provides dense coverage, with network RTK as the primary positioning service. Navigation enhancement signals broadcast by low-Earth orbit (LEO) satellites are used to assist and accelerate carrier phase ambiguity fixing, thereby shortening the initialization time. Carrier phase ambiguity fixing refers to the process of determining the integer solutions of integer unknowns in the carrier phase observations through algorithms, a crucial step in achieving centimeter-level high-precision positioning. The high-speed movement of LEO satellites relative to ground users provides a wide range of changing observation geometry configurations within a short time, effectively accelerating the search and fixing of carrier phase ambiguities, thus reducing the initialization time from tens of seconds in traditional schemes to seconds.

[0042] In the suburban transition zone mode, the enhanced CORS network has sparse coverage, relying primarily on navigation augmentation signals broadcast by low-Earth orbit (LEO) satellites for positioning services. The enhanced CORS network provides satellite-to-ground computation results to update the generation parameters of the navigation augmentation signals. LEO signals fill the gaps in the enhanced CORS network, maintaining centimeter-level positioning accuracy. Enhanced CORS network gaps refer to areas such as suburbs and rural areas where the density of ground reference stations is low, with distances between stations reaching tens or even hundreds of kilometers. Users are far from the nearest reference station, leading to a decrease in the accuracy of network RTK error modeling and making it difficult to maintain centimeter-level positioning accuracy. In these situations, relying on navigation augmentation signals broadcast by LEO satellites as the primary positioning service leverages the global coverage and rapid geometric changes of LEO satellites to provide augmentation information to users in the enhanced CORS network gap areas, compensating for insufficient ground network coverage and thus maintaining centimeter-level positioning accuracy.

[0043] In remote area mode, where there is no enhanced CORS network coverage (such as in oceans, deserts, and mountainous regions), positioning services are provided using navigation augmentation signals broadcast by LEO satellites, leveraging the global coverage characteristics of LEO satellites. Inter-satellite links maintain the continuity and consistency of augmentation information. Inter-satellite links refer to communication links established between LEO satellites to enable data exchange and time synchronization between satellites within the LEO satellite constellation.

[0044] The corresponding beneficial effects are as follows: This implementation method, through a dynamic resource scheduling mechanism, adaptively selects the optimal positioning service mode based on the spatiotemporal relationship between the low-Earth orbit satellite transit trajectory and the coverage area of ​​the enhanced CORS network, as well as user distribution needs. In areas with dense enhanced CORS networks, low-Earth orbit is used to accelerate initialization; in areas with sparse enhanced CORS networks, low-Earth orbit is used to fill coverage gaps; and in areas without enhanced CORS network coverage, the global coverage characteristics of low-Earth orbit are used to maintain service. This achieves optimal allocation of satellite and ground resources and adaptive adjustment of positioning service performance, thereby expanding the system's coverage capability across the entire region, eliminating service blind spots, and significantly improving service availability in remote areas.

[0045] As another specific implementation method, for the LEO-assisted rapid initialization technology, in this implementation method, the space-ground collaborative control center is also used to perform rapid initialization. Specifically, the space-ground collaborative control center is also used to combine the onboard GNSS observation data in the downlink data with the GNSS observation data and LEO satellite signal observation data in the CORS observation data to estimate the regional ionospheric delay gradient in real time. The ionospheric delay gradient refers to the rate of change of ionospheric delay in space, which is a key factor affecting the accuracy of long baseline RTK positioning. LEO satellite observations are not affected by the troposphere, and the ionospheric puncture point changes rapidly. By combining multi-station coverage data from the enhanced CORS network, accurate estimation of the ionospheric delay gradient can be achieved.

[0046] Simultaneously, the space-ground coordinated control center also uses low-Earth orbit (LEO) satellites as mobile reference stations, forming short baseline combinations with ground reference stations. A mobile reference station refers to treating an LEO satellite as a dynamic reference station whose position changes rapidly over time, providing diverse observation geometries. Utilizing the rapid geometric changes of LEO satellites and users, multiple sets of observation equations are established in a short time to achieve carrier phase ambiguity fixation within a single epoch. A single epoch means that ambiguity fixation can be completed using only data from a single observation epoch, eliminating the need for observation accumulation over multiple epochs, thus achieving convergence within seconds.

[0047] The corresponding beneficial effects are as follows: This implementation method estimates the ionospheric delay gradient in real time by combining onboard GNSS observation data in downlink data and GNSS observation data and low-Earth orbit satellite signal observation data in CORS observation data. Compared with traditional modeling methods, it significantly improves the accuracy of ionospheric estimation and improves the initialization performance of long baseline RTK. By using low-Earth orbit satellites as mobile reference stations and taking advantage of their rapid geometric change characteristics, carrier phase ambiguity is fixed in a single epoch, reducing the RTK initialization time from minutes to seconds, which meets the requirements of rapid convergence for high-dynamic applications such as autonomous driving and UAV control.

[0048] As another specific implementation method, for the space-ground joint integrity monitoring mechanism, in this implementation method, the space-ground collaborative control center is also used to perform space-ground joint integrity monitoring, which includes autonomous monitoring of the space segment, independent monitoring of the ground segment, and cross-verification monitoring between space and ground.

[0049] The autonomous monitoring of the space segment includes: real-time monitoring of the status of the onboard multi-frequency GNSS receiver, the frequency stability of the atomic clock, and the status of the navigation enhancement signal generation and transmission link via low-Earth orbit satellites. When any equipment failure or signal abnormality is detected in the onboard multi-frequency GNSS receiver status, atomic clock frequency stability, or navigation enhancement signal generation and transmission link status, the system automatically switches to the backup equipment and broadcasts the equipment status indicator.

[0050] Ground-based independent monitoring includes at least one of the following: monitoring the signal quality of navigation augmentation signals via the enhanced CORS network; comparing navigation augmentation signals received by various ground reference stations via the enhanced CORS network; and comparing satellite ephemeris clock errors in downlink data with ephemeris clock errors in the satellite-ground co-operation control center. Specifically, monitoring the signal quality of navigation augmentation signals broadcast by low-Earth orbit satellites via the enhanced CORS network includes detecting arrival power, carrier-to-noise ratio, and Doppler shift consistency; comparing navigation augmentation signals received by various ground reference stations via the enhanced CORS network includes detecting message content consistency and time synchronization in the navigation augmentation signals; and comparing satellite ephemeris clock errors in downlink data with ephemeris clock errors in the satellite-ground co-operation control center includes comparing the satellite ephemeris in the downlink data with the ephemeris in the satellite-ground co-operation control center to obtain ephemeris comparison results, and comparing the satellite clock errors in the downlink data with the clock errors in the satellite-ground co-operation control center to obtain clock error comparison results.

[0051] The satellite-to-ground cross-verification monitoring includes triggering an integrity alarm when the difference between the satellite ephemeris clock difference in the downlink data and the ephemeris clock difference in the satellite-to-ground solution exceeds a threshold. Specifically, the satellite-to-ground cross-verification monitoring includes triggering an integrity alarm when the ephemeris comparison result or clock difference comparison result exceeds a preset threshold, i.e., the difference between the satellite ephemeris in the downlink data and the ephemeris in the satellite-to-ground solution exceeds a preset threshold, or the difference between the satellite clock difference in the downlink data and the clock difference in the satellite-to-ground solution exceeds a preset threshold. The satellite-to-ground collaborative control center will then automatically switch to a backup data source or a downgraded positioning service mode, and broadcast integrity risk information to the user to guide the user in taking countermeasures.

[0052] The corresponding beneficial effects are as follows: This implementation method, through autonomous monitoring of the space segment, independent monitoring of the ground segment, and cross-verification monitoring between space and ground, differs from single on-board monitoring and independent ground monitoring. This implementation method can achieve cross-verification of multi-source information, effectively identify low-Earth orbit anomalies or CORS observation data anomalies, reduce the navigation service risk miss rate to an extremely low level, and meet the integrity requirements of high-safety scenarios such as aviation and autonomous driving. Through unified risk decision-making and service management by the space-ground collaborative control center, when anomalies are detected, the system automatically switches backup data sources or degrades services and broadcasts integrity risk information to users, significantly enhancing the safety and reliability of the system.

[0053] As another specific implementation, regarding the specific composition of the navigation enhancement payload, in this implementation, the navigation enhancement payload is a standard navigation enhancement payload, specifically including a spaceborne multi-frequency GNSS receiver, an inter-satellite link unit, a navigation enhancement signal generation unit, and a data injection receiving module.

[0054] The onboard multi-frequency GNSS receiver is used to receive GNSS signals for onboard autonomous orbit determination (with meter-level accuracy) and to provide the basic data for generating navigation enhancement signals. Onboard autonomous orbit determination refers to the process by which a low-Earth orbit satellite independently calculates its own orbit and clock bias using GNSS signals received by the onboard GNSS receiver.

[0055] Inter-satellite link units are used to achieve communication and time synchronization between satellites within a low-Earth orbit constellation. As another implementation of this embodiment, the inter-satellite link unit uses a laser link, supporting on-orbit data interaction and constellation collaboration. Distinguished from the "inter-satellite link" mentioned above, the inter-satellite link unit in this embodiment refers to the processing unit within the navigation enhancement payload of the low-Earth orbit satellite that enables inter-satellite communication and time synchronization. The "inter-satellite link" mentioned above specifically refers to "the communication link established between low-Earth orbit satellites," and the two are not contradictory.

[0056] The navigation enhancement signal generation unit is used to generate and broadcast navigation enhancement signals, which include enhancement information such as precise orbit, clock error correction, and ionospheric model.

[0057] The data injection receiving module is used to receive the satellite-to-ground calculation results generated by the satellite-to-ground cooperative control center via the Ka-band uplink of the ground station, in order to update the generation parameters of the navigation enhancement signal. As another implementation of this embodiment, in addition to the Ka-band, the S-band, X-band, or laser communication link can also be used to receive the satellite-to-ground calculation results.

[0058] The corresponding beneficial effects are as follows: This implementation adopts a standard navigation enhancement payload, eliminating the need for onboard CORS data reception and complex collaborative processing functions. Unlike complex architectures requiring onboard collaborative processing, in this implementation, the low-Earth orbit satellite does not directly receive CORS observation data or perform onboard collaborative orbit determination calculations, significantly reducing onboard complexity, payload weight, power consumption, and cost, and improving satellite platform reliability, making it more suitable for large-scale constellation deployments. The satellite receives the satellite-ground calculation results (including precise ephemeris and clock bias data from the low-Earth orbit satellite) from a ground-based satellite-ground collaborative control center via a data injection receiving module. All precise processing algorithms are deployed on the ground, eliminating the need for changes to onboard hardware or software during system upgrades and maintenance, significantly reducing the total lifecycle maintenance cost and enhancing the system's sustainable development capabilities.

[0059] As another specific implementation, regarding the specific structure of the hybrid enhancement receiver, in this implementation, the hybrid enhancement receiver includes a multi-mode receiving module and a cooperative positioning solution engine.

[0060] The multi-mode receiver module is used to simultaneously receive GNSS signals, navigation enhancement signals broadcast by low-orbit satellites, and differential data (specifically VRS differential data) provided by the ground segment.

[0061] The collaborative positioning engine is used to perform multi-source fusion positioning calculations, adaptively selecting the calculation mode based on the positioning service mode. In this embodiment, the fusion calculation method supports Precise Point Positioning (PPP)-RTK fusion calculations and inertial navigation tight integration. PPP refers to a technology that uses GNSS signals received by a single hybrid augmentation receiver and satellite-to-ground calculation results to achieve centimeter-level positioning. PPP-RTK fusion calculation refers to the collaborative positioning engine simultaneously utilizing navigation augmentation signals broadcast by low-Earth orbit satellites (providing precise orbits, clock corrections, ionospheric models, etc.) and differential data (VRS differential data) provided by the ground segment, achieving complementary advantages of the two technologies through a unified data processing framework. Inertial navigation tight integration refers to a calculation method that deeply fuses the observation values ​​of GNSS / low-Earth orbit augmentation / differential data with the measurements of the inertial navigation system (INS) at the observation level.

[0062] The system adaptively selects the solution mode based on the positioning service mode (urban dense area mode, suburban transition zone mode, and remote area mode) broadcast by the satellite-ground collaborative control center to achieve optimal positioning performance. For example, if the positioning service mode is "urban dense area mode", RTK solution is preferred; if the positioning service mode is "suburban transition zone mode", PPP-RTK fusion solution is preferred; and if the positioning service mode is "remote area mode", PPP solution is preferred.

[0063] As another implementation of this embodiment, the hybrid augmentation receiver further includes an integrity monitoring module. This module receives joint satellite-ground integrity information broadcast by the satellite-ground collaborative control center and performs autonomous integrity monitoring. When the joint satellite-ground integrity information is abnormal or triggers an alarm, or when an abnormality is detected by the autonomous integrity monitoring, an alarm is triggered or a location service switch is performed. Joint satellite-ground integrity information refers to the result information obtained from performing joint satellite-ground integrity monitoring. Autonomous integrity monitoring refers to the technology where the hybrid augmentation receiver uses observation data from multiple low-Earth orbit satellites it receives to perform data verification, detect, and eliminate faulty low-Earth orbit satellites. Data verification includes at least one of: redundant observation, consistency verification, fault detection, and fault identification and elimination. It should be noted that the detection process and methods of autonomous integrity monitoring itself are existing technologies and will not be elaborated here. However, unlike existing technologies, the autonomous integrity monitoring in this embodiment, combined with the joint satellite-ground integrity information broadcast by the satellite-ground collaborative control center, forms a dual protection mechanism, expanding the fault detection range and improving detection accuracy.

[0064] The corresponding beneficial effects are as follows: This implementation method simultaneously receives GNSS signals, LOR augmentation signals, and differential data through a multi-mode receiving module, providing a data foundation for multi-source fusion positioning; the collaborative positioning solution engine adaptively selects the solution mode according to the positioning service mode, supports PPP-RTK fusion solution, and achieves optimal positioning performance in different scenarios; the integrity monitoring module receives satellite-ground joint integrity information and performs autonomous integrity monitoring of the hybrid augmentation receiver, triggering alarms or switching positioning services when anomalies are detected, further improving the security and reliability of the user end.

[0065] In another embodiment of this solution, such as Figure 3 As shown, a method for low-Earth orbit (LEO) satellite navigation enhancement and ground-based CORS cooperative positioning is provided. This method is applied to any of the LEO satellite navigation enhancement and ground-based CORS cooperative systems described in the foregoing embodiments. The method includes the following steps: S1 receives GNSS signals and navigation enhancement signals broadcast by low-orbit satellites through various ground reference stations, and generates CORS observation data which is then transmitted in real time to the space-ground collaborative control center. The specific implementation process is as follows: S101, in the enhanced CORS network, each ground reference station adds a low-Earth orbit (LEO) signal receiving channel to its existing receivers capable of receiving multi-frequency GNSS signals, achieving "dual-purpose use of one station." Each ground reference station continuously receives GNSS signals (including signals broadcast by medium- and high-Earth orbit navigation satellites such as BeiDou Navigation Satellite System (BDS), Global Positioning System (GPS), and Galileo) and navigation enhancement signals broadcast by LEO satellites, 24 / 7. CORS observation data refers to the collective term for GNSS observation data (pseudorange, carrier phase, Doppler, etc.) collected by ground reference stations and LEO satellite signal observation data (signal power, carrier-to-noise ratio, Doppler shift, etc.).

[0066] S102, each ground reference station transmits CORS observation data back to the space-ground collaborative control center in real time through high-speed communication equipment (fiber optic or fifth-generation mobile communication technology).

[0067] S2 receives downlink data and CORS observation data from low-Earth orbit (LEO) satellites through the space-ground collaborative control center; performs precise orbit determination calculations on the LEO satellites based on the downlink data and CORS observation data to obtain the space-ground calculation results; the specific process of uplinking the space-ground calculation results to the LEO satellites is as follows: S201, the ground-based joint control center, receives two types of data sources. The first type is downlink data from low-Earth orbit (LEO) satellites, which refers to data broadcast to the ground via space-to-ground links, including onboard GNSS observation data, satellite ephemeris, and satellite clock bias. The second type is CORS observation data transmitted from various ground reference stations.

[0068] In S202, the space-ground collaborative processing unit in the space-ground collaborative control center fuses two types of data to perform precise orbit determination calculations. Precise orbit determination calculations refer to the process of determining the precise orbital parameters (including position, velocity, orbital elements, etc.) and clock bias parameters of a low-Earth orbit (LEO) satellite in an inertial or Earth-fixed frame using multiple observation data and high-precision mathematical models and parameter estimation methods. Specifically, the space-ground collaborative processing unit in the space-ground collaborative control center fuses onboard GNSS observation data from the LEO satellite downlink data and GNSS observation data from the CORS observation data. A Kalman filter algorithm is used to estimate the precise orbit and clock bias parameters of the LEO satellite in real time, generating precise ephemeris and clock bias correction products, i.e., the space-ground calculation results. The accuracy of the space-ground calculation results can reach the centimeter level.

[0069] In S203, the space-ground collaborative control center transmits the space-ground calculation results to the low-Earth orbit satellite via the Ka-band uplink from the ground station. The uplink uses the Ka-band for high-speed data transmission, ensuring that the space-ground calculation results are updated to the low-Earth orbit satellite in a timely manner. In addition to the Ka-band, the S-band, X-band, or laser communication links can also be used to transmit the space-ground calculation results.

[0070] S3, the specific implementation process of updating the generation parameters of the navigation enhancement signal based on the satellite-to-ground calculation results via low-Earth orbit satellites and broadcasting the updated navigation enhancement signal is as follows: The S301 low-Earth orbit satellite carries a navigation enhancement payload that includes a data injection receiving module and a navigation enhancement signal generation unit. The data injection receiving module receives the uplink satellite-to-ground calculation results (precise ephemeris and clock bias data) from the satellite-to-ground collaborative control center, and updates the generation parameters of the navigation enhancement signal based on the received satellite-to-ground calculation results, thereby updating the parameter configuration in the navigation enhancement signal generation process.

[0071] S302, the navigation augmentation signal generation unit generates navigation augmentation signals based on the updated parameter configuration and broadcasts them to ground users via the L-band or B3C band. The broadcast navigation augmentation signals contain augmentation information such as precise orbits, clock corrections, and ionospheric models, ensuring that the accuracy of the broadcast navigation augmentation signals is consistent with the ground-based calculation results.

[0072] S4, the specific implementation process of receiving GNSS signals, navigation enhancement signals, and differential data through a hybrid enhancement receiver, and performing multi-source fusion positioning calculation based on GNSS signals, navigation enhancement signals, and differential data is as follows: The S401 hybrid augmentation receiver includes a multi-mode receiver module for simultaneously receiving three types of positioning data sources: GNSS signals, navigation augmentation signals, and differential data. GNSS signals: signals broadcast by medium- and high-orbit navigation satellites such as BeiDou Navigation Satellite System (BDS), Global Positioning System (GPS), and Galileo; navigation augmentation signals: navigation augmentation signals broadcast by low-orbit satellites, containing augmentation information such as precise orbits, clock corrections, and ionospheric models; differential data: VRS differential data generated by the ground segment through a network RTK processing center.

[0073] S402, the cooperative positioning engine in the hybrid augmentation receiver performs multi-source fusion positioning. Multi-source fusion positioning refers to the process of comprehensively processing navigation and positioning observation data from different sources and of different types, and achieving higher accuracy and reliability positioning through data fusion algorithms. For example, the collaborative positioning engine adaptively selects the optimal solution mode based on the positioning service mode (urban dense area mode, suburban transition zone mode, and remote area mode) broadcast by the satellite-ground collaborative control center: In the urban dense area mode, the CORS network has dense coverage, and the network RTK is the main positioning service. The navigation enhancement signals broadcast by low-orbit satellites are used to help accelerate the fixation of carrier phase ambiguity, reducing the initialization time to the second level; In the suburban transition zone mode, the CORS network has sparse coverage, and the navigation enhancement signals broadcast by low-orbit satellites are the main positioning service. PPP or PPP-RTK fusion solution is used, and the low-orbit signals are used to fill the gaps in the CORS network to maintain centimeter-level positioning accuracy; In the remote area mode, there is no CORS network coverage, and only the navigation enhancement signals broadcast by low-orbit satellites are used. The precise point positioning (PPP) solution is used, relying on the global coverage characteristics of low-orbit satellites to maintain positioning service.

[0074] In the above embodiments, although the steps are numbered S1, S2, etc., they are only specific embodiments given by the present invention. Those skilled in the art can adjust the execution order of S1, S2, etc. according to the actual situation, and these situations are also within the protection scope of the present invention. It can be understood that in some embodiments, some or all of the above embodiments may be included.

[0075] Furthermore, the acquisition process of the data involved in this application follows the principles of legality, legitimacy, and necessity. Based on obtaining the explicit authorization and consent of the user, only the minimum necessary information required to achieve the purpose is collected, and data security protection obligations are fulfilled in accordance with the law.

[0076] It should be noted that the beneficial effects of the low-Earth orbit satellite navigation enhancement and ground CORS cooperative positioning method provided in the above embodiments are the same as the beneficial effects of the low-Earth orbit satellite navigation enhancement and ground CORS cooperative system described above, and will not be repeated here. Furthermore, the system provided in the above embodiments is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the system can be divided into different functional modules according to the actual situation to complete all or part of the functions described above. In addition, the system and method embodiments provided in the above embodiments belong to the same concept, and their specific implementation process is detailed in the method embodiments, and will not be repeated here.

[0077] like Figure 4As shown, an embodiment of the present invention provides a computer device 300, which includes a processor 320 coupled to a memory 310. The memory 310 stores at least one computer program 330, which is loaded and executed by the processor 320 to enable the computer device 300 to implement any of the above-described methods. Specifically: The computer device 300 can vary considerably due to differences in configuration or performance. It may include one or more processors 320 (Central Processing Units, CPUs) and one or more memories 310. The one or more memories 310 store at least one computer program 330, which is loaded and executed by the one or more processors 320 to enable the computer device 300 to implement the low-Earth orbit satellite navigation enhancement and ground CORS cooperative positioning method provided in the above embodiments. Of course, the computer device 300 may also have wired or wireless network interfaces, a keyboard, and input / output interfaces for input and output. The computer device 300 may also include other components for implementing device functions, which will not be elaborated upon here.

[0078] An embodiment of the present invention provides a computer-readable storage medium storing at least one computer program, which is loaded and executed by a processor to enable a computer to implement any of the above-described methods.

[0079] Alternatively, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, a floppy disk, and an optical data storage device, etc.

[0080] In an exemplary embodiment, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform any of the aforementioned low-Earth orbit satellite navigation enhancement and ground CORS cooperative positioning methods.

[0081] It should be noted that the terms "first," "second," etc., used in the specification of this application are used to distinguish similar objects and represent a limitation on a specific order or sequence. Where appropriate, the order of use for similar objects can be interchanged so that the embodiments of this application described herein can be implemented in an order other than that shown in the figures or description.

[0082] Those skilled in the art will recognize that this invention can be implemented as a system, method, or computer program product. Therefore, this disclosure can be specifically implemented in the following forms: it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "circuit," "module," or "system." Furthermore, in some embodiments, the invention can also be implemented as a computer program product contained in one or more computer-readable media, which includes computer-readable program code.

[0083] Any combination of one or more computer-readable media may be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0084] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A low earth orbit satellite navigation augmentation and ground CORS collaboration system, characterized in that, include: Space segment, ground segment, and user segment; The space segment includes low-Earth orbit satellites, which carry navigation enhancement payloads for broadcasting navigation enhancement signals; The ground segment includes an enhanced CORS network and a space-ground coordination control center; each ground reference station in the enhanced CORS network is used to receive GNSS signals and the navigation enhancement signals, and to transmit the CORS observation data generated by each ground reference station to the space-ground coordination control center in real time; The space-ground collaborative control center is used to receive downlink data from the low-Earth orbit satellite and CORS observation data, perform precise orbit determination calculation on the low-Earth orbit satellite based on the downlink data and CORS observation data, obtain the space-ground calculation result of the low-Earth orbit satellite, and inject the space-ground calculation result uplink into the low-Earth orbit satellite to update the generation parameters of the navigation enhancement signal. The user segment includes a hybrid augmentation receiver for receiving the GNSS signal, the navigation augmentation signal, and differential data provided by the ground segment, and performing multi-source fusion positioning calculation based on the GNSS signal, the navigation augmentation signal, and the differential data. 2.The low earth orbit satellite navigation enhancement and ground CORS coordination system according to claim 1, wherein, In the enhanced CORS network, each ground reference station is equipped with a low-orbit signal receiving channel in addition to the receiver with multi-frequency GNSS signal receiving capability, for receiving the GNSS signals and the navigation enhancement signals; The space-ground collaborative control center includes a low-orbit signal monitoring subsystem, a network RTK processing center, and a space-ground collaborative processing unit. The low-orbit signal monitoring subsystem is used to process the CORS observation data transmitted from various ground reference stations and monitor signal quality indicators. The network RTK processing center is used to generate VRS differential data based on the CORS observation data and provide network RTK services; The satellite-ground collaborative processing unit is used to perform precise orbit determination calculations on the low-orbit satellite based on the downlink data and the CORS observation data, and obtain the satellite-ground calculation results.

3. The low-orbit satellite navigation enhancement and ground CORS collaborative system according to claim 1, characterized in that, The satellite-ground collaborative control center is also used to determine the regional results of satellite-ground joint coverage based on the transit trajectory of the low-orbit satellite and the coverage of the enhanced CORS network; determine the positioning accuracy requirements based on user positioning information and application scenarios; and select a positioning service mode based on the regional results and the positioning accuracy requirements, including urban dense area mode, suburban transition zone mode and remote area mode. In the urban dense area mode, the network RTK is the primary positioning service, and the navigation enhancement signal is used to assist in accelerating carrier phase ambiguity fixation to shorten the initialization time. In the suburban transition zone mode, the navigation enhancement signal is used as the primary positioning service, and the enhanced CORS network is used to provide the satellite-to-ground solution results to update the generation parameters of the navigation enhancement signal; In the remote area mode, where there is no enhanced CORS network coverage, positioning services are provided using the navigation enhancement signals based on the global coverage characteristics of low-Earth orbit satellites.

4. The low-orbit satellite navigation enhancement and ground CORS collaborative system according to claim 1, characterized in that, The space-ground collaborative control center is also used to combine the onboard GNSS observation data in the downlink data with the GNSS observation data and low-orbit satellite signal observation data in the CORS observation data to estimate the regional ionospheric delay gradient in real time. The low-orbit satellite is used as a mobile reference station to form a short baseline combination with the ground reference station, so as to achieve carrier phase ambiguity fixation in a single epoch.

5. A low-orbit satellite navigation enhancement and ground CORS collaborative system according to claim 1, characterized in that, The space-ground joint control center is also used to perform space-ground joint integrity monitoring, which includes autonomous monitoring of the space segment, independent monitoring of the ground segment, and cross-verification monitoring between space and ground. The autonomous monitoring of the space segment includes: monitoring the status of the onboard multi-frequency GNSS receiver, the frequency stability of the atomic clock, and the status of the navigation enhancement signal generation and transmission link through the low-Earth orbit satellite; The independent ground segment monitoring includes: monitoring the signal quality of the navigation enhancement signal through the enhanced CORS network, and / or comparing the navigation enhancement signal received by various ground reference stations through the enhanced CORS network, and / or comparing the satellite ephemeris clock difference in the downlink data with the ephemeris clock difference in the satellite-ground co-operation control center; The satellite-to-ground cross-verification monitoring includes triggering an integrity alarm when the difference between the satellite ephemeris clock difference in the downlink data and the ephemeris clock difference in the satellite-to-ground solution exceeds a threshold.

6. A low-orbit satellite navigation enhancement and ground CORS collaborative system according to claim 1, characterized in that, The navigation enhancement payload includes: a spaceborne multi-frequency GNSS receiver, an inter-satellite link unit, a navigation enhancement signal generation unit, and a data injection receiving module; The onboard multi-frequency GNSS receiver is used to receive GNSS signals, for onboard autonomous orbit determination, and to provide the basic data for generating the navigation enhancement signals. The inter-satellite link unit is used to enable communication and time synchronization between satellites within the low-Earth orbit constellation; The navigation enhancement signal generation unit is used to generate and broadcast the navigation enhancement signal; The data injection receiving module is used to receive the satellite-ground calculation results generated by the satellite-ground cooperative control center, so as to update the generation parameters of the navigation enhancement signal.

7. A low-orbit satellite navigation enhancement and ground CORS collaborative system according to claim 3, characterized in that, The hybrid enhancement receiver includes a multi-mode receiving module and a cooperative positioning solution engine; The multimode receiving module is used to receive the GNSS signal, the navigation enhancement signal, and the differential data; The collaborative positioning solution engine is used to perform multi-source fusion positioning solution and adaptively selects the solution mode according to the positioning service mode.

8. A method for low-Earth orbit satellite navigation enhancement and ground-based CORS cooperative positioning, applied to a low-Earth orbit satellite navigation enhancement and ground-based CORS cooperative system as described in any one of claims 1 to 7, characterized in that, include: The system receives GNSS signals and navigation enhancement signals broadcast by low-orbit satellites through various ground reference stations, and generates CORS observation data which is then transmitted to the space-ground collaborative control center in real time. The satellite-ground collaborative control center receives downlink data from the low-orbit satellite and CORS observation data. Based on the downlink data and the CORS observation data, a precise orbit determination calculation is performed on the low-Earth orbit satellite to obtain the satellite-to-ground calculation results. The satellite-to-ground calculation results are then uploaded and injected into the low-orbit satellite. The low-orbit satellite updates the generation parameters of the navigation enhancement signal based on the satellite-to-ground calculation results, and broadcasts the updated navigation enhancement signal. The GNSS signal, the navigation enhancement signal, and the differential data are received by a hybrid enhancement receiver, and multi-source fusion positioning calculation is performed based on the GNSS signal, the navigation enhancement signal, and the differential data.

9. A computer device, characterized in that, The computer device includes a processor coupled to a memory, the memory storing at least one computer program, which is loaded and executed by the processor to enable the computer device to implement the low-orbit satellite navigation enhancement and ground CORS cooperative positioning method as described in claim 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one computer program, which is loaded and executed by a processor to enable the computer to implement the low-orbit satellite navigation enhancement and ground CORS cooperative positioning method as described in claim 8.

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