Auxiliary anti-deception positioning method, device and system for low-orbit satellite
By using a low-orbit satellite-assisted GNSS system and employing message data consistency comparison and ephemeris information deviation analysis, redundant information sources are constructed, solving the problem of GNSS system deception attacks in complex electromagnetic environments and achieving efficient anti-deception positioning.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-03-31
AI Technical Summary
Existing GNSS systems are vulnerable to spoofing attacks in complex electromagnetic environments, leading to a decrease in positioning accuracy. Furthermore, existing anti-spoofing technologies are costly or require additional sensors.
By introducing the original navigation information from low-Earth orbit (LEO) satellites, and utilizing their dynamic characteristics and high-density deployment, we can perform consistency comparisons of GNSS satellite message data and analyze deviations in key ephemeris information to construct a redundant information source resistant to deception. This is combined with pseudorange point positioning calculations and Kalman filtering for precise positioning.
Without altering the signal system or receiver hardware, this method improves the reliability and security of the positioning system, effectively identifies and suppresses spoofing signals, provides sufficient data redundancy, and reduces the difficulty of implementing spoofing attacks.
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Figure CN121763316A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of satellite positioning technology, specifically to a low-orbit satellite-assisted anti-spoofing positioning method, device, and system. Background Technology
[0002] The Global Navigation Satellite System (GNSS) provides fundamental services such as navigation, positioning, and timing, offering core support in fields like intelligent transportation, emergency management, and life safety. However, with the increasingly complex electromagnetic environment, the low power of GNSS signals and their open code structure pose significant security risks. Therefore, there is an urgent need to enhance the security capabilities of satellite navigation. Summary of the Invention
[0003] To address at least some of the aforementioned technical problems, embodiments of this application provide a low-orbit satellite-assisted anti-spoofing positioning method, apparatus, and system.
[0004] On one hand, embodiments of this application provide a low-Earth orbit (LEO) satellite-assisted anti-spoofing positioning method, comprising: receiving navigation raw information broadcast by GNSS satellites and LEO satellites, wherein the navigation raw information broadcast by the LEO satellites includes local satellite observation data and message data and GNSS satellite message data visible to the local satellite, and the navigation raw information broadcast by the GNSS satellites includes local satellite observation data and message data; based on the GNSS satellite message data broadcast by the LEO satellites and the local satellite message data broadcast by the GNSS satellites, filtering target GNSS satellite observation data and message data from the navigation raw information; and generating positioning information for a receiver based on the target GNSS satellite observation data and message data and the LEO satellite observation data and message data.
[0005] In some embodiments, the step of filtering target GNSS satellite observation data and message data from the navigation raw information based on the GNSS satellite message data broadcast by the low-Earth orbit satellite and the local satellite message data broadcast by the GNSS satellite includes: filtering valid GNSS satellite message data broadcast by the low-Earth orbit satellite based on GNSS satellite message data broadcast by multiple low-Earth orbit satellites; and filtering target GNSS satellite observation data and message data based on the valid GNSS satellite message data broadcast by the low-Earth orbit satellite and the local satellite message data broadcast by the GNSS satellite.
[0006] In some embodiments, the step of filtering valid GNSS satellite message data broadcast by multiple low-Earth orbit satellites based on the GNSS satellite message data broadcast by multiple low-Earth orbit satellites includes: performing a consistency comparison on the message data of the same GNSS satellite broadcast by multiple low-Earth orbit satellites to obtain a comparison result; and obtaining the valid GNSS satellite message data broadcast by the low-Earth orbit satellites based on the comparison result.
[0007] In some embodiments, the step of filtering target GNSS satellite observation data and message data based on the valid GNSS satellite message data broadcast by the low-Earth orbit satellite and the local satellite message data broadcast by the GNSS satellite includes: calculating a first value of key ephemeris information of the corresponding GNSS satellite based on the valid GNSS satellite message data broadcast by the low-Earth orbit satellite, wherein the key ephemeris information includes at least one of the following: orbit information, clock information, and position information; calculating a second value of key ephemeris information of the GNSS satellite based on the local satellite message data broadcast by the GNSS satellite; calculating a deviation value of key ephemeris information of each GNSS satellite based on the first and second values of key ephemeris information of each GNSS satellite; and determining target GNSS satellite observation data and message data based on the deviation values of key ephemeris information of each GNSS satellite.
[0008] In some embodiments, determining the target GNSS satellite observation data and message data based on the deviation value of the key ephemeris information of each of the GNSS satellites includes: if the deviation value of the key ephemeris information of a GNSS satellite is less than a first preset value, then determining the observation data and message data broadcast by the GNSS satellite as the target GNSS satellite observation data and message data.
[0009] In some embodiments, determining the observation data and message data broadcast by the GNSS satellite as target GNSS satellite observation data and message data if the deviation value of the key ephemeris information of the GNSS satellite is less than a first preset value includes: if the deviation value of the key ephemeris information of the GNSS satellite is less than the first preset value, performing a first-order linear fit on the deviation value of the key ephemeris information of the GNSS satellite within a set time window to obtain a fitting function; if the slope of the fitting function is less than a second preset value, then determining the observation data and message data broadcast by the GNSS satellite as target GNSS satellite observation data and message data.
[0010] In some embodiments, generating receiver positioning information based on the target GNSS satellite observation data and message data, and the low-Earth orbit satellite observation data and message data, includes: calculating approximate state parameters of the receiver using pseudorange point positioning based on the target GNSS satellite observation data and message data, and the low-Earth orbit satellite observation data and message data; using the approximate state parameters of the receiver, performing a refined model correction of the system error sources on the low-Earth orbit satellite observation data and the target GNSS satellite observation data to obtain refined corrected observation data; constructing a precise point positioning equation using the refined corrected observation data; and estimating parameters based on the precise point positioning equation using Kalman filtering or its improved method to obtain the receiver positioning information.
[0011] In some embodiments, before receiving the original navigation information broadcast by GNSS satellites and low-orbit satellites, the low-orbit satellites have achieved time and space reference synchronization through inter-satellite links.
[0012] In some embodiments, the process of achieving spatiotemporal reference synchronization between the low-Earth orbit (LEO) satellites via inter-satellite links is as follows: The ground control center acquires multiple data sources, including at least one of the following: downlink observation data from GNSS satellites collected by the LEO satellites; observation data and message data from GNSS satellites and LEO satellites collected by ground monitoring stations of the LEO satellite navigation system; navigation enhancement messages broadcast by the LEO satellites containing the orbits and clock biases of the local satellite and GNSS satellites; and observation data and message data from GNSS satellites provided by ground-based GNSS tracking stations. Based on these multiple data sources, the ground control center jointly processes and generates precise orbit parameters, precise clock bias parameters, and system integrity information. The ground control center then uploads the precise orbit parameters, precise clock bias parameters, and system integrity information to each LEO satellite after message arrangement. Each LEO satellite utilizes the precise orbit parameters, precise clock bias parameters, and system integrity information, and performs bidirectional communication and ranging via inter-satellite links to achieve spatiotemporal reference synchronization between the LEO satellites.
[0013] On the other hand, this application embodiment also provides a low-orbit satellite-assisted anti-spoofing positioning device, comprising: a receiving module, configured to receive navigation raw information broadcast by GNSS satellites and low-orbit satellites, wherein the navigation raw information broadcast by the low-orbit satellites includes local satellite observation data and message data and local visible GNSS satellite message data, and the navigation raw information broadcast by the GNSS satellites includes local satellite observation data and message data; and a calculation module, configured to, based on the GNSS satellite message data broadcast by the low-orbit satellites and the local satellite message data broadcast by the GNSS satellites, filter target GNSS satellite observation data and message data from the navigation raw information; and generate positioning information for the receiver based on the target GNSS satellite observation data and message data and the low-orbit satellite observation data and message data.
[0014] Furthermore, embodiments of this application also provide an anti-spoofing positioning system, comprising: GNSS satellites broadcast raw navigation information, which includes local observation data and message data. The low-orbit satellite receives GNSS satellite message data visible to the local satellite and broadcasts raw navigation information. The raw navigation information broadcast by the low-orbit satellite includes local satellite observation data and message data, as well as GNSS satellite message data visible to the local satellite. The receiver receives the raw navigation information broadcast by the GNSS satellite and the low-orbit satellite. Based on the GNSS satellite message data broadcast by the low-orbit satellite and the local satellite message data broadcast by the GNSS satellite, it filters the target GNSS satellite observation data and message data from the raw navigation information, and generates the receiver's positioning information according to the target GNSS satellite observation data and message data and the low-orbit satellite observation data and message data.
[0015] In some embodiments, the system further includes: a ground monitoring station for a low-Earth orbit (LEO) satellite navigation system, for collecting observation data and message data of the GNSS satellite and the LEO satellite, as well as navigation enhancement messages broadcast by the LEO satellite containing the orbits and clock biases of the local satellite and the GNSS satellite; and a ground control center, for acquiring multiple data sources, the multiple data sources including at least one of the following: downlink observation data of the GNSS satellite collected by the LEO satellite, observation data and message data of the GNSS satellite and the LEO satellite collected by the ground monitoring station for the LEO satellite navigation system, and navigation enhancement messages broadcast by the LEO satellite containing the orbits and clock biases of the local satellite and the GNSS satellite; The system utilizes navigation enhancement messages based on satellite orbits and clock biases, as well as observation and message data from GNSS ground-based tracking stations. Based on these multiple data sources, it jointly processes and generates precise orbit parameters, precise clock bias parameters, and system integrity information. These precise orbit parameters, precise clock bias parameters, and system integrity information are then coded and uploaded to each of the low-Earth orbit (LEO) satellites. This allows each LEO satellite to utilize these precise orbit parameters, precise clock bias parameters, and system integrity information, and to conduct bidirectional communication and ranging via inter-satellite links, thereby achieving temporal and spatial reference synchronization among the LEO satellites.
[0016] This application also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the methods described in any of the above embodiments.
[0017] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods described in any of the above embodiments.
[0018] This application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the methods described in any of the above embodiments.
[0019] The low-Earth orbit (LEO) satellite-assisted anti-spoofing positioning method, apparatus, and system provided in this application construct a critical redundant information source for anti-spoofing by introducing the original navigation information from LEO satellites. LEO satellites possess significant dynamic characteristics and high deployment density, making them less susceptible to attacks and deception. Simultaneously, the navigation signal broadcasting, augmentation information broadcasting, and monitoring data from high-Earth orbit (NEO) GNSS satellites provided by LEO satellites greatly increase the difficulty of implementing deception attacks. Therefore, this method provides sufficient data redundancy for deception detection, identification, and suppression without requiring additional navigation sensors, effectively improving the reliability and security of the positioning system. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a diagram illustrating navigation attack methods.
[0021] Figure 2 This is a schematic flowchart of a low-orbit satellite-assisted anti-spoofing positioning method provided in an embodiment of this application.
[0022] Figure 3 This is a schematic diagram of the structure of a navigation system provided in one embodiment of this application.
[0023] Figure 4 This is a partial flowchart of a low-orbit satellite-assisted anti-spoofing positioning method provided in an embodiment of this application.
[0024] Figure 5 This is a partial flowchart of a low-orbit satellite-assisted anti-spoofing positioning method provided in an embodiment of this application.
[0025] Figure 6 This is a partial flowchart of a low-orbit satellite-assisted anti-spoofing positioning method provided in an embodiment of this application.
[0026] Figure 7 This is a partial flowchart of a low-orbit satellite-assisted anti-spoofing positioning method provided in an embodiment of this application.
[0027] Figure 8 This is a partial flowchart of a low-orbit satellite-assisted anti-spoofing positioning method provided in an embodiment of this application.
[0028] Figure 9 This is a schematic flowchart of a low-orbit satellite-assisted anti-spoofing positioning method provided in an embodiment of this application.
[0029] Figure 10 This is a partial flowchart of a low-orbit satellite-assisted anti-spoofing positioning method provided in an embodiment of this application.
[0030] Figure 11 This is a schematic diagram of the message generation and uploading process provided in an embodiment of this application.
[0031] Figure 12 This is a schematic diagram of the structure of a low-orbit satellite-assisted anti-spoofing positioning device according to an embodiment of this application.
[0032] Figure 13This is a schematic diagram of the structure of an anti-spoofing positioning system proposed in one embodiment of this application.
[0033] Figure 14 This is a schematic diagram of the physical structure of an electronic device provided in an embodiment of this application. Detailed Implementation
[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and their descriptions are used to explain this application, but are not intended to limit this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily arranged.
[0035] The terms “first,” “second,” etc., used in this document are not intended to specifically refer to order or sequence, nor are they used to limit this application; they are merely used to distinguish elements or operations described using the same technical terms.
[0036] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0037] The term "and / or" as used in this document includes any or all of the items mentioned.
[0038] To better understand this application, the research background of this application will be explained in detail below.
[0039] like Figure 1As shown, navigation attack measures are manifested in the space segment, ground segment, and user segment, and are mainly divided into three categories: physical damage, network attacks, and electromagnetic interference. Electromagnetic interference, due to its low implementation cost and high hazard, has become the most widely used cost-effective navigation attack method. Electromagnetic interference can be divided into suppression jamming and deception jamming. Navigation suppression jamming uses high-power jammers to emit various signals, causing damage or failure of the target receiver's accuracy. Deception jamming generates deceptive satellite signals that are highly similar to real signals or relays real satellite signals, causing the receiver terminal to receive false information under covert conditions, thus achieving the purpose of deception. Compared with suppression jamming, deception jamming has better concealment, lower power, lower technical difficulty, and stronger controllability, and can achieve precise interference to the target receiver. To a certain extent, deception jamming has a stronger survivability. Spoofing jamming can be divided into relay-based spoofing and generative spoofing. Relay-based spoofing involves the spoofing source receiving a real satellite signal, amplifying its power after a certain time delay, and then transmitting it to the target receiver via an antenna. This relay-based generation mode cannot alter the satellite navigation message data; it can only achieve spoofing jamming by controlling the time delay of the satellite signal reaching the target receiver. Therefore, this method has poor control over the solution results, and its inherent drawback (the spoofing signal always arrives at the receiver later than the real signal) allows it to be eliminated by existing multipath suppression techniques. Generative spoofing signal technology does not rely on satellite signals and can independently generate spoofing signals. Generative jamming pre-receives satellite signals, detects key information such as satellite pseudocode, navigation message, and clock parameters, and then generates a pseudocode signal with the highest correlation to it. It also tamperes with the satellite ephemeris and clock parameters to produce a spoofing signal with characteristics very similar to the real signal, enticing the receiver to capture and track it, leading to positioning errors. Therefore, generative spoofing is more concealed, and its defense technology is a key focus of anti-spoofing research.
[0040] Anti-spoofing technologies can be categorized into three types at the system level: satellite-based, receiver-based, and multi-sensor-assisted anti-spoofing.
[0041] On-board anti-spoofing technology fundamentally enhances the anti-spoofing capability of navigation signals by encrypting, dynamically embedding features, or optimizing the signal structure at the satellite end. Specifically, this includes: encryption and authentication mechanisms, which generate dynamic keys on-board to verify signal source identity; signal power enhancement mechanisms, which increase signal transmission power by more than 30dB compared to traditional GNSS to suppress spoofing signal interference; dynamic signal feature embedding technology, which utilizes changes in satellite geometry to generate uncopyable dynamic signal fingerprints; and inter-satellite link collaboration, which establishes a trusted network through inter-satellite communication to cross-verify signal integrity in real time.
[0042] Anti-spoofing receiver technology detects and suppresses spoofing signals in real time through signal processing algorithms, multi-band fusion, or data quality assessment. Specifically, this includes: signal monitoring and interference suppression, such as real-time spectrum analysis combined with adaptive notch filtering, or detecting signal distortion using multiple correlators; and multi-GNSS fusion, combining GPS / BeiDou / Galileo and other multi-band signals to identify spoofing signals by exploiting the spatiotemporal inconsistencies between multiple systems.
[0043] Multi-sensor-assisted anti-spoofing technology enhances anti-spoofing capabilities by fusing data from multiple sources, including inertial navigation systems, visual / LiDAR, and geomagnetic sensors, to construct a redundant positioning system. Specifically, this includes: inertial-assisted anti-spoofing technology, which provides short-term, high-precision pose information or geometric satellite-to-ground distance through angular velocity / acceleration integration, and cross-validates this with GNSS positioning results; and LiDAR / visual sensor-based anti-spoofing technology, which calculates independent positioning results through environmental feature matching and compares them with GNSS data to detect spoofing.
[0044] Among them, on-board anti-spoofing technology is the most direct and effective, often used by special users, but its workflow is complex and costly; receiver anti-spoofing technology identifies spoofing signals at the signal level, but it is difficult to adapt to the ever-evolving spoofing attack methods; auxiliary anti-spoofing technology uses redundant observation information from multi-sensor fusion technology to assist in the identification of spoofing signals, which is more in line with the requirements of flexible PNT (Positioning, Navigation and Timing) for the utilization of redundant information, but requires users to configure additional inertial, visual and other navigation equipment.
[0045] With the development of Low Earth Orbit (LEO) satellite technology, utilizing LEO satellites for navigation signal broadcasting, enhanced information broadcasting, and GNSS monitoring of medium and high orbit satellites has the potential to provide sufficient redundant information for anti-spoofing navigation services without requiring users to configure additional navigation sensors. Therefore, researching anti-spoofing navigation service technology based on LEO satellites is an effective way to address the threat of spoofing attacks to navigation security and has practical significance for improving reliable navigation telemetry (PNT) assurance capabilities.
[0046] Therefore, this application provides a low-Earth orbit satellite-assisted anti-spoofing positioning method, which can improve the ability to identify and defend against false information interference without changing the signal system, receiver hardware, or configuring additional navigation sensors at a high cost. The execution subject of the low-Earth orbit satellite-assisted anti-spoofing positioning method provided in this application includes, but is not limited to, a computer.
[0047] Figure 2 This is a flowchart illustrating a low-orbit satellite-assisted anti-spoofing positioning method according to an embodiment of this application, as shown below. Figure 2As shown in the embodiments of this application, the low-orbit satellite-assisted anti-spoofing positioning method includes: S1. Receive the original navigation information broadcast by GNSS satellites and low-orbit satellites, wherein the original navigation information broadcast by the low-orbit satellites includes local satellite observation data and message data and GNSS satellite message data visible to the local satellite, and the original navigation information broadcast by the GNSS satellites includes local satellite observation data and message data. In step S1, GNSS includes, but is not limited to, the US Global Positioning System (GPS), the Chinese BeiDou Navigation Satellite System (BDS), and the European Union's Galileo Satellite Navigation System (Galileo). The raw navigation information refers to data directly received from the satellite downlink, without receiver processing or computation. GNSS satellites broadcast raw navigation information provide traditional basic positioning signals; low-Earth orbit (LEO) satellites broadcast raw navigation information provide sufficient redundancy. Specifically, LEO satellites broadcast raw navigation signals to the receiver, which may include local satellite observation data and message data, as well as multi-GNSS satellite message data under certain visibility conditions; GNSS satellites broadcast raw navigation signals to the receiver, which may include GNSS observation data and message data; the service architecture is as follows... Figure 3 As shown. The receiver receives the raw navigation signals broadcast by GNSS and LEO satellites.
[0048] S2. Based on the GNSS satellite message data broadcast by the low-orbit satellite and the local satellite message data broadcast by the GNSS satellite, filter the target GNSS satellite observation data and message data from the original navigation information; In step S2, by combining the GNSS satellite message data broadcast by the low-orbit satellite and the local satellite message data broadcast by the GNSS satellite, fraudulent information and information that does not meet the requirements can be eliminated, and the target GNSS satellite observation data and message data can be obtained in the end.
[0049] S3. Based on the target GNSS satellite observation data and message data and the low-orbit satellite observation data and message data, generate the receiver's positioning information.
[0050] In step S3, the receiver's positioning information can be generated by combining low-orbit satellite observation data and message data with target GNSS satellite observation data and message data.
[0051] In steps S2 to S3, the positioning information of the receiver is finally obtained by jointly processing the raw navigation information broadcast by GNSS satellites and low-orbit satellites.
[0052] The low-Earth orbit (LEO) satellite-assisted anti-spoofing positioning method provided in this application constructs a key redundant information source for anti-spoofing by introducing the original navigation information from LEO satellites. LEO satellites possess significant dynamic characteristics and high deployment density, making them less susceptible to attacks and deception. Simultaneously, the navigation signal broadcasting, augmentation information broadcasting, and monitoring data from high-Earth orbit (NEO) GNSS satellites provided by LEO satellites greatly increase the difficulty of implementing deception attacks. Therefore, this method does not require additional navigation sensors to provide sufficient data redundancy for deception detection, identification, and suppression, effectively improving the reliability and security of the positioning system.
[0053] like Figure 4 As shown, in some embodiments, the filtering of target GNSS satellite observation data and message data from the original navigation information based on the GNSS satellite message data broadcast by the low-orbit satellite and the local satellite message data broadcast by the GNSS satellite includes: S211. Based on the GNSS satellite message data broadcast by multiple low-orbit satellites, filter the valid GNSS satellite message data broadcast by the low-orbit satellites; In step S211, a consistency comparison can be performed on the message data of the same GNSS satellite broadcast by different low-orbit satellites to identify possible fraudulent information and retain valid GNSS satellite message data.
[0054] S212. Based on the valid GNSS satellite message data broadcast by the low-orbit satellite and the local satellite message data broadcast by the GNSS satellite, filter the target GNSS satellite observation data and message data.
[0055] In step S212, for the same GNSS satellite, the message data of the GNSS satellite broadcast by the low-orbit satellite and the local message data broadcast by the GNSS satellite are combined, and data that does not meet the requirements are eliminated, thereby selecting the target GNSS satellite observation data and message data.
[0056] like Figure 5 As shown, in some embodiments, the step of filtering valid GNSS satellite message data broadcast by the low-Earth orbit satellites based on the GNSS satellite message data broadcast by the multiple low-Earth orbit satellites includes: S2111. Perform a consistency comparison on the message data of the same GNSS satellite broadcast by multiple low-orbit satellites to obtain the comparison results; In step S2111, a consistency comparison is performed on the message data of the same GNSS satellite broadcast by different LEO satellites to eliminate GNSS satellite observation data and message data with abnormal messages. Specifically, the consistency of messages of the same GNSS satellite broadcast by different LEO satellites is compared. When the ephemeris reference time (toe) and clock reference time (toc) of multiple LEO satellites are consistent with those of a certain GNSS satellite, a consistency comparison is performed on the message of that GNSS satellite.
[0057] S2112. Based on the comparison results, obtain the valid GNSS satellite message data broadcast by the low-orbit satellite.
[0058] In step S2112, when the comparison results are inconsistent, the GNSS satellite message with consistent comparison results is required to be used, and the inconsistent message is eliminated (the principle of credit majority can be adopted).
[0059] like Figure 6 As shown, in some embodiments, the process of filtering target GNSS satellite observation data and message data based on the effective GNSS satellite message data broadcast by the low-Earth orbit satellite and the local satellite message data broadcast by the GNSS satellite includes: S2121. Based on the effective GNSS satellite message data broadcast by the low-orbit satellite, calculate the first value of the key ephemeris information of the corresponding GNSS satellite, wherein the key ephemeris information includes at least one of the following: orbit information, clock information, and position information; S2122. Based on the local satellite message data broadcast by the GNSS satellite, calculate the second value of the key ephemeris information of the GNSS satellite; S2123. Based on the first and second values of the key ephemeris information of each GNSS satellite, calculate the deviation value of the key ephemeris information of each GNSS satellite; S2124. Based on the deviation values of the key ephemeris information of each of the GNSS satellites, determine the target GNSS satellite observation data and message data.
[0060] Specifically, taking one of the GNSS satellites as an example, the valid GNSS satellite messages selected after consistency comparison are compared with the messages broadcast by the corresponding GNSS satellite. That is, based on the corresponding message algorithm, the key ephemeris data, such as satellite position data, calculated based on the GNSS satellite messages broadcast by the LEO satellite and the messages broadcast by the GNSS satellite itself are compared. If the deviation value of the two key ephemeris information of a GNSS satellite exceeds a certain deviation threshold, the message and observation data of that GNSS satellite are removed. That is, no data from that GNSS satellite is used for positioning calculations until GNSS satellite observation data and message data that meet the accuracy comparison requirements are found.
[0061] In some embodiments, determining the target GNSS satellite observation data and message data based on the deviation value of the key ephemeris information of each of the GNSS satellites includes: if the deviation value of the key ephemeris information of a GNSS satellite is less than a first preset value, then determining the observation data and message data broadcast by the GNSS satellite as the target GNSS satellite observation data and message data.
[0062] Specifically, if the deviation between two key ephemeris information of a GNSS satellite exceeds a first set value, the GNSS satellite's message and observation data will be discarded. That is, no data from that GNSS satellite will be used for positioning calculations until a GNSS satellite message data with a matching accuracy is found. The observation data and message data broadcast by that GNSS satellite will then be used as the target GNSS satellite observation data and message data.
[0063] like Figure 7 As shown, in some embodiments, if the deviation value of the key ephemeris information of the GNSS satellite is less than a first preset value, then the observation data and message data broadcast by the GNSS satellite are determined to be the observation data and message data of the target GNSS satellite, including: S21241. If the deviation value of the key ephemeris information of the GNSS satellite is less than the first set value, then perform a first-order linear fitting on the deviation value of the key ephemeris information of the GNSS satellite within the set time window to obtain the fitting function. S21242. If the slope of the fitting function is less than the second set value, then the observation data and message data broadcast by the GNSS satellite are determined to be the target GNSS satellite observation data and message data.
[0064] For example, the orbital deviation and clock deviation threshold parameters are configured to be 1m (this parameter can be adjusted flexibly). Messages from GNSS satellites with out-of-tolerance errors are removed. In addition, a first-order fit is performed on the orbital deviation and clock deviation within a certain time window. If the slope is greater than 2cm (this parameter can be adjusted flexibly), it is considered that the GNSS satellite is broadcasting a deceptive signal, and the observation data and message data broadcast by that GNSS satellite are removed (it is also possible to choose whether to retain the observation data of that GNSS satellite according to the observation redundancy requirements). The remaining observation data and message data broadcast by the GNSS satellite are used as the target GNSS satellite observation data and message data.
[0065] like Figure 8 As shown, in some embodiments, generating receiver positioning information based on the target GNSS satellite observation data and message data and the low-orbit satellite observation data and message data includes: S221. Based on the target GNSS satellite observation data and message data and the low-orbit satellite observation data and message data, calculate the approximate state parameters of the receiver using pseudorange single-point positioning. S222. Using the approximate state parameters of the receiver, perform a refined model correction on the system error source of the low-orbit satellite observation data and the target GNSS satellite observation data to obtain the refined observation data. S223. Using the refined and corrected observation data, construct a precise single-point positioning equation; S224. Based on the precise single-point positioning equation, parameter estimation is performed using Kalman filtering or its improved method to obtain the positioning information of the receiver.
[0066] Specifically, based on the observation and message data of the target GNSS satellite and the observation and message data of the low-orbit satellite, multi-frequency pseudorange and phase observation data of GNSS and LEO satellites are obtained, as well as precise orbit, clock error and other correction information of the local satellite and GNSS satellites broadcast by the LEO satellite.
[0067] Then, the pseudorange observations were corrected for modeling errors such as ionospheric, tropospheric, and relativistic effects. The ionospheric delay was corrected using the BDGIM model, and the dry delay of the ionosphere was corrected using the saastamoinen model.
[0068] Next, a linearized SPP observation equation is constructed, in which the satellite position is calculated using local and GNSS satellite messages broadcast by the LEO satellite during the approximate satellite-to-ground distance calculation process. Then, the pseudorange observations are corrected for modeling errors such as ionospheric, tropospheric, and relativistic effects. The ionospheric delay is corrected using the BDGIM model, and the ionospheric dry delay is corrected using the saastamoinen model. Finally, the approximate receiver position, clock error, and system bias parameters are obtained using SPP based on least squares iteration. After obtaining the approximate state parameters, the systematic error sources are modeled and corrected. The systematic error sources such as phase center offset of satellite antenna and receiver antenna, relativistic effects, phase winding error, Earth rotation, solid tide, ocean tide, polar tide, etc. are modeled and the satellite coordinates, receiver coordinates or observation values are corrected. After correcting for system model errors, linearized measurement equations for Precise Point Positioning (PPP) using GNSS and LEO satellites are constructed. A dual-frequency ionospheric-free model is used to uniformly process pseudorange and carrier phase observations, eliminating the influence of ionospheric delay. The matrix form of the linearized measurement model is as follows:
[0069] in, For state vectors, To linearize the measurement matrix; To measure noise, This is the measurement vector.
[0070] After eliminating out-of-tolerance equations through quality control, the parameters to be estimated are updated. k Taking time as an example, the process of estimating the floating-point solution of the state using the extended Kalman filter is as follows:
[0071] in, Let k be the state transition matrix from time k-1 to time k; , They are respectively k State prediction and state covariance prediction at time t; , They are respectively k-1 State prediction and state covariance prediction at time t; for k-1 to k The process noise covariance matrix at time step; For measuring noise matrix; Here is the Kalman gain matrix. for k Linearized measurement matrix at time step, for k The measurement vector at time.
[0072] To mitigate the impact of navigation spoofing induced by non-message anomalies (such as generative spoofing or suppression jamming) on state estimation, and to reduce the influence of anomalous GNSS satellite signals whose message parameters have not been rebroadcast by LEO satellites, the IGG III adaptive robust model can be used in Kalman measurement updates.
[0073] in, , These are empirical constants; The first linearized residual vector is the first linearized residual vector. One element, another , Then the error discrimination statistic for:
[0074] use right Tuning is performed to obtain :
[0075] in, for The Middle OK Column elements, . use replace Subsequently, the energy gain of the corresponding measurement channel will be weakened to suppress the impact of deception attacks.
[0076] Analyze the post-test residuals, and if there are out-of-tolerance observation equations, perform quality control again and iteratively estimate the floating-point solution of the state until the requirements are met.
[0077] In summary, the low-orbit satellite-assisted anti-spoofing positioning process provided in one embodiment of this application is as follows: Figure 9 As shown, by comparing the consistency of LEO inter-satellite GNSS messages and comparing the accuracy of LEO broadcast and GNSS broadcast messages, GNSS message spoofing is identified, abnormal GNSS satellite data is eliminated, and LEO-assisted anti-spoofing precise single-point positioning is achieved.
[0078] As can be seen, the positioning method provided in this application fully utilizes the wide-area coverage of low-orbit satellites, the global monitoring capabilities of space-based systems, and the characteristics of redundant message information broadcasting. Under high-cost operating conditions such as not changing the signal system on the system side, not changing the receiver hardware, and not configuring other navigation sensors, it improves the generative deception identification and defense capabilities through LEO inter-satellite message consistency comparison, LEO and GNSS broadcast orbit difference analysis, and adaptive robustness mechanism.
[0079] In addition, low-Earth orbit (LEO) satellites not only have significant dynamic characteristics and high deployment density, making them less likely to be targeted by attacks and deception, but also the mechanisms of LEO satellite-based navigation signal broadcasting, enhanced information broadcasting, and GNSS mid-to-high orbit satellite monitoring can greatly increase the difficulty of deception attacks, providing sufficient redundant information for deception detection, identification, and suppression without adding other navigation sensors.
[0080] In some embodiments, before receiving the original navigation information broadcast by GNSS satellites and low-orbit satellites, the low-orbit satellites have achieved time and space reference synchronization through inter-satellite links.
[0081] like Figure 10 As shown, in some embodiments, the process of achieving time and space reference synchronization between the low-orbit satellites through inter-satellite links is as follows: S10. The ground control center acquires multiple data sources, including at least one of the following: downlink observation data of GNSS satellites collected by the low-orbit satellites, observation data and message data of the GNSS satellites and the low-orbit satellites collected by the ground monitoring station of the low-orbit satellite navigation system, navigation enhancement messages broadcast by the low-orbit satellites containing the orbits and clock differences of the local satellite and GNSS satellites, and observation data and message data of the GNSS satellites provided by the GNSS ground-based tracking station; S20. The ground control center, based on the multiple data sources, jointly processes and generates precise orbital parameters, precise clock error parameters, and system integrity information; S30. The ground control center transmits the precise orbit parameters, the precise clock error parameters, and the system integrity information to each of the low-orbit satellites after electronic message arrangement. S40. Each of the low-orbit satellites utilizes the precise orbital parameters, the precise clock error parameters, and the system integrity information, and performs bidirectional communication and ranging via inter-satellite links to achieve time and space reference synchronization among the low-orbit satellites.
[0082] Specifically, LEO satellites receive and store downlink observation data from high-orbit satellites in the global navigation satellite system under certain visibility conditions. The observation data includes multi-band pseudorange, phase, Doppler, and carrier-to-noise ratio data, and the stored data is downloaded based on ground download commands. The ground segment of the low-orbit navigation system receives observation data and message data from GNSS and LEO satellites received by various monitoring stations. The observation data includes multi-band pseudorange, phase, Doppler, and carrier-to-noise ratio data. The message data includes GNSS broadcast orbit, clock bias, and other message data, as well as LEO satellite broadcast local satellite and GNSS medium and high orbit satellite orbit and clock bias, and pushes them to the ground operation and control center. The operations control center can also receive observation data and message data from external IGS / iGMAS stations to support precise orbit and clock error determination. The observation data includes multi-GNSS, multi-band pseudorange, carrier, Doppler and carrier-to-noise ratio data. The operations control center combines the pseudorange standard point positioning (SPP) results based on LEO space-based monitoring data with the orbit information based on GNSS broadcast messages to obtain the orbit information of GNSS satellites and LEO satellites. After orbit integration, the initial satellite orbit information is generated. The joint support spatiotemporal information processing unit generates products such as orbit and clock bias, as well as integrity information. After message arrangement, this information is uploaded to low-Earth orbit (LEO) navigation satellites. LEO satellites communicate and measure with each other via inter-satellite links (ISL), achieving full-network LEO spatiotemporal reference synchronization. The message generation and uploading process is as follows: Figure 11As shown.
[0083] Figure 12 This is a schematic diagram of the structure of a low-orbit satellite-assisted anti-spoofing positioning device according to an embodiment of this application, as shown below. Figure 12 As shown in the embodiment of this application, a low-orbit satellite-assisted anti-spoofing positioning device includes: The receiving module 31 is used to receive the original navigation information broadcast by GNSS satellites and low-orbit satellites. The original navigation information broadcast by the low-orbit satellites includes local satellite observation data and message data, as well as GNSS satellite message data visible to the local satellite. The original navigation information broadcast by the GNSS satellites includes local satellite observation data and message data. The calculation module 32 is used to filter target GNSS satellite observation data and message data from the navigation raw information based on the GNSS satellite message data broadcast by the low-orbit satellite and the local satellite message data broadcast by the GNSS satellite; and to generate receiver positioning information based on the target GNSS satellite observation data and message data and the low-orbit satellite observation data and message data.
[0084] The embodiments of the device provided in this application can be used to execute the processing flow of the above-described low-orbit satellite-assisted anti-spoofing positioning method embodiments. Its functions will not be repeated here, but can be referred to the detailed description of the above method embodiments.
[0085] Figure 13 This is a schematic diagram of the structure of an anti-spoofing positioning system proposed in one embodiment of this application, as shown below. Figure 13 As shown in the embodiment of this application, an anti-spoofing positioning system includes: GNSS satellite 41 broadcasts raw navigation information, which includes local observation data and message data. Low-Earth orbit satellite 42 receives GNSS satellite message data visible to the local satellite and broadcasts original navigation information. The original navigation information broadcast by the low-Earth orbit satellite 42 includes local satellite observation data and message data, as well as GNSS satellite message data visible to the local satellite. Receiver 43 receives the raw navigation information broadcast by GNSS satellite 41 and low-orbit satellite 42. Based on the GNSS satellite message data broadcast by low-orbit satellite 42 and the local satellite message data broadcast by GNSS satellite 41, it filters the target GNSS satellite observation data and message data from the raw navigation information. Based on the target GNSS satellite observation data and message data and the low-orbit satellite observation data and message data, it generates the receiver's positioning information.
[0086] In some embodiments, the anti-spoofing positioning system further includes: a low-Earth orbit (LEO) satellite navigation system ground monitoring station, which collects observation data and message data of the GNSS satellite and the LEO satellite, as well as navigation enhancement messages broadcast by the LEO satellite containing the orbits and clock biases of the local satellite and the GNSS satellite; and a ground control center, which acquires multiple data sources, including at least one of the following: downlink observation data of the GNSS satellite collected by the LEO satellite, observation data and message data of the GNSS satellite and the LEO satellite collected by the LEO satellite navigation system ground monitoring station, and navigation enhancement messages broadcast by the LEO satellite containing the orbits and clock biases of the local satellite and the GNSS satellite; The system utilizes navigation enhancement messages based on SS satellite orbits and clock biases, as well as observation and message data from GNSS ground-based tracking stations. Based on these multiple data sources, it jointly processes and generates precise orbit parameters, precise clock bias parameters, and system integrity information. These precise orbit parameters, precise clock bias parameters, and system integrity information are then coded and uploaded to each of the low-Earth orbit (LEO) satellites. This allows each LEO satellite to utilize these precise orbit parameters, precise clock bias parameters, and system integrity information, and to conduct bidirectional communication and ranging via inter-satellite links, thereby achieving temporal and spatial reference synchronization among the LEO satellites.
[0087] Figure 14 This is a schematic diagram of the physical structure of an electronic device provided in an embodiment of this application, as shown below. Figure 14 As shown, the electronic device may include a processor 501, a communications interface 502, a memory 503, and a communication bus 504, wherein the processor 501, the communications interface 502, and the memory 503 communicate with each other via the communication bus 504. The processor 501 may call logical instructions in the memory 503 to execute the methods described in any of the above embodiments.
[0088] Furthermore, the logical instructions in the aforementioned memory 503 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0089] This embodiment discloses a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by a computer, the computer can perform the methods provided in the above-described method embodiments.
[0090] This embodiment provides a computer-readable storage medium storing a computer program that causes the computer to perform the methods provided in the above-described method embodiments.
[0091] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0092] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, produce a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0093] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0094] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0095] In the description of this specification, the references to terms such as "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0096] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A low earth orbit satellite assisted anti-spoofing positioning method, characterized in that, The method comprises the following steps: Receiving navigation raw information broadcast by GNSS satellites and low-orbit satellites, wherein the navigation raw information broadcast by the low-orbit satellites comprises observation data and text data of the satellites and text data of GNSS satellites visible to the satellites, and the navigation raw information broadcast by the GNSS satellites comprises observation data and text data of the satellites; Filtering target GNSS satellite observation data and text data from the navigation raw information based on the text data of the GNSS satellites broadcast by the low-orbit satellites and the text data of the satellites broadcast by the GNSS satellites; Generating positioning information of a receiver according to the target GNSS satellite observation data and text data and the observation data and text data of the low-orbit satellites.
2. The method of claim 1, wherein, The step of filtering target GNSS satellite observation data and text data from the navigation raw information based on the text data of the GNSS satellites broadcast by the low-orbit satellites and the text data of the satellites broadcast by the GNSS satellites comprises the following steps: Filtering effective GNSS satellite text data broadcast by the low-orbit satellites based on the text data of the GNSS satellites broadcast by the low-orbit satellites; Filtering target GNSS satellite observation data and text data based on the effective GNSS satellite text data broadcast by the low-orbit satellites and the text data of the satellites broadcast by the GNSS satellites.
3. The method of claim 2, wherein, The step of filtering effective GNSS satellite text data broadcast by the low-orbit satellites based on the text data of the GNSS satellites broadcast by the low-orbit satellites comprises the following steps: Performing consistency comparison on the text data of the same GNSS satellites broadcast by the low-orbit satellites to obtain comparison results; Obtaining the effective GNSS satellite text data broadcast by the low-orbit satellites according to the comparison results.
4. The method according to claim 2 or 3, characterized in that, The step of filtering target GNSS satellite observation data and text data based on the effective GNSS satellite text data broadcast by the low-orbit satellites and the text data of the satellites broadcast by the GNSS satellites comprises the following steps: Calculating a first value of key ephemeris information of a corresponding GNSS satellite based on the effective GNSS satellite text data broadcast by the low-orbit satellites, wherein the key ephemeris information comprises at least one of the following: orbit information, clock information, and position information; Calculating a second value of the key ephemeris information of the GNSS satellite based on the text data of the satellites broadcast by the GNSS satellites; Calculating a deviation value of the key ephemeris information of each GNSS satellite based on the first value and the second value of the key ephemeris information of each GNSS satellite; Determining target GNSS satellite observation data and text data based on the deviation value of the key ephemeris information of each GNSS satellite.
5. The method of claim 4, wherein, The step of determining target GNSS satellite observation data and text data based on the deviation value of the key ephemeris information of each GNSS satellite comprises the following step: If the deviation value of the key ephemeris information of a GNSS satellite is less than a first set value, determining that the observation data and text data broadcast by the GNSS satellite are target GNSS satellite observation data and text data.
6. The method of claim 5, wherein, If the bias value of the key ephemeris information of one of the GNSS satellites is less than a first set value, it is determined that the observation data and text data broadcast by the GNSS satellite is target GNSS satellite observation data and text data, including: If the bias value of the key ephemeris information of one of the GNSS satellites is less than a first set value, a first-order linear fitting is performed on the bias value of the key ephemeris information of the GNSS satellite in a set time window to obtain a fitting function; If the slope of the fitting function is less than a second set value, it is determined that the observation data and text data broadcast by the GNSS satellite is target GNSS satellite observation data and text data.
7. The method of claim 1, wherein, The target GNSS satellite observation data and text data and the observation data and text data of the low-orbit satellite are used to generate positioning information of a receiver, including: The target GNSS satellite observation data and text data and the observation data and text data of the low-orbit satellite are used to solve the rough state parameters of the receiver by pseudorange single point positioning; The rough state parameters of the receiver are used to correct the observation data of the low-orbit satellite and the target GNSS satellite observation data by a system error source refinement model to obtain refined corrected observation data; The refined corrected observation data is used to construct a precise single point positioning equation; Based on the precise single point positioning equation, parameter estimation is performed by Kalman filtering or improved method to obtain the positioning information of the receiver.
8. The method of claim 1, wherein, Before receiving the navigation raw information broadcast by the GNSS satellites and the low-orbit satellites, the low-orbit satellites have realized time and space reference synchronization through inter-satellite links.
9. The method of claim 8, wherein, The process of realizing time and space reference synchronization between the low-orbit satellites through inter-satellite links is as follows: A ground operation and control center obtains multiple data sources, including at least one of the following: GNSS satellite downlink observation data collected by the low-orbit satellite, observation data and text data of the GNSS satellite and the low-orbit satellite collected by a low-orbit satellite navigation system ground monitoring station, and navigation enhancement text broadcast by the low-orbit satellite containing the orbits and clock errors of the satellites and the GNSS satellites, and observation data and text data of the GNSS satellites provided by a GNSS ground tracking station; The ground operation and control center jointly processes and generates precise orbit parameters, precise clock error parameters and system integrity information based on the multiple data sources; The ground operation and control center uploads the precise orbit parameters, the precise clock error parameters and the system integrity information to each low-orbit satellite after text arrangement; Each low-orbit satellite uses the precise orbit parameters, the precise clock error parameters and the system integrity information, and realizes time and space reference synchronization between the low-orbit satellites through bidirectional communication and ranging through inter-satellite links.
10. A low earth orbit satellite assisted anti-spoofing positioning apparatus, characterized by, The receiving module is configured to receive navigation raw information broadcast by GNSS satellites and low-orbit satellites, wherein the navigation raw information broadcast by the low-orbit satellites includes satellite observation data and text data and GNSS satellite text data visible to the satellite, and the navigation raw information broadcast by the GNSS satellites includes satellite observation data and text data; The computing module is configured to filter target GNSS satellite observation data and text data from the navigation raw information based on the text data of the GNSS satellite broadcast by the low-orbit satellite and the text data of the current satellite broadcast by the GNSS satellite, and generate positioning information of the receiver based on the target GNSS satellite observation data and text data and the observation data and text data of the low-orbit satellite.
11. An anti-spoofing positioning system, characterized by The application comprises: GNSS satellites for broadcasting navigation raw information, wherein the navigation raw information broadcast by the GNSS satellites comprises observation data and text data of the current satellite; low-orbit satellites for receiving text data of GNSS satellites visible to the current satellite and broadcasting navigation raw information, wherein the navigation raw information broadcast by the low-orbit satellites comprises observation data and text data of the current satellite and text data of GNSS satellites visible to the current satellite; receivers for receiving the navigation raw information broadcast by the GNSS satellites and the low-orbit satellites, filtering target GNSS satellite observation data and text data from the navigation raw information based on the text data of the GNSS satellite broadcast by the low-orbit satellite and the text data of the current satellite broadcast by the GNSS satellite, and generating positioning information of the receiver based on the target GNSS satellite observation data and text data and the observation data and text data of the low-orbit satellite.
12. The anti-spoofing positioning system of claim 11, wherein, The application further comprises: low-orbit satellite navigation system ground monitoring stations for collecting observation data and text data of the GNSS satellites and the low-orbit satellites and navigation enhancement text broadcast by the low-orbit satellites, wherein the navigation enhancement text comprises orbit and clock difference of the current satellite and the GNSS satellites; ground control centers for obtaining multiple data sources, wherein the multiple data sources comprise at least one of the following: GNSS satellite downlink observation data collected by the low-orbit satellites, observation data and text data of the GNSS satellites and the low-orbit satellites collected by the low-orbit satellite navigation system ground monitoring stations, and navigation enhancement text broadcast by the low-orbit satellites, wherein the navigation enhancement text comprises orbit and clock difference of the current satellite and the GNSS satellites, and observation data and text data of the GNSS satellites provided by GNSS ground tracking stations; based on the multiple data sources, joint processing and generation of precise orbit parameters, precise clock difference parameters and system integrity information; after text arrangement, the precise orbit parameters, the precise clock difference parameters and the system integrity information are uploaded to each low-orbit satellite, so that each low-orbit satellite utilizes the precise orbit parameters, the precise clock difference parameters and the system integrity information, and realizes time and space reference synchronization between the low-orbit satellites through inter-satellite link bidirectional communication and ranging.
13. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the method of any one of claims 1 to 9.