Railway user terminal adaptive positioning method and system

Abstract

The invention provides a railway user terminal adaptive positioning method and system, and relates to the technical field of wireless communication networks, and the method comprises the steps: determining that a target railway user terminal currently accesses a railway Beidou application service platform through terminal account login; if yes, a real-time positioning service based on a target positioning mode corresponding to the positioning precision requirement type is provided for the terminal according to the positioning precision requirement type of the terminal so as to send real-time positioning data to the terminal, and the target positioning mode comprises a precision single-point positioning and real-time dynamic positioning mode or a real-time dynamic differential positioning mode; and providing a corresponding real-time reference conversion service for the terminal according to the reference conversion demand type of the terminal so as to send real-time reference conversion data to the terminal, so that the terminal corrects the real-time positioning data according to the real-time reference conversion data. According to the invention, a high-precision self-adaptive elastic positioning service can be provided for the railway user terminal, so that the positioning precision, the dynamic adaptability, the reliability and the effectiveness of the railway user terminal can be effectively improved.

Description

Technical Field

[0001] This application relates to the field of wireless communication network technology, and in particular to an adaptive positioning method and system for railway user terminals. Background Technology

[0002] The railway industry's demand for high-precision positioning services is increasing, and the service targets are gradually shifting towards large-scale, multi-type, multi-level, and multi-environmental applications. The demand for high-precision positioning is also developing towards greater specialization and refinement across all disciplines. The BeiDou ground-based augmentation network for railways has become a new type of railway infrastructure, providing real-time high-precision positioning services for railway user terminals.

[0003] Currently, existing railway user terminal positioning services suffer from limited product variety and are unable to meet the high-precision positioning service requirements under complex terrain, railway user terminal operating environments, complex atmospheric conditions, signal interference, and diverse user needs. In particular, for high-precision control measurement and positioning applications in complex and rugged mountainous areas, existing railway user terminal positioning services still rely mainly on traditional real-time kinematic (RTK), network real-time kinematic (RTK), or virtual reference station (VRS) technologies. These technologies primarily depend on ground-based benchmark station networks to provide ground-based services, making it difficult to match the real-time impact of terrain changes and multipath effects in complex environments.

[0004] Therefore, how to provide more reliable and effective positioning services for railway user terminals and other applications through a unified platform is a current challenge for high-precision positioning services in the railway industry. Summary of the Invention

[0005] In view of this, embodiments of this application provide an adaptive positioning method and system for railway user terminals to eliminate or improve one or more defects existing in the prior art.

[0006] One aspect of this application provides an adaptive positioning method for railway user terminals, comprising: If it is determined that the current access method of the target railway user terminal to the railway Beidou application service platform is terminal account login access, then according to the positioning accuracy requirement type corresponding to the target railway user terminal, a real-time positioning service based on the target positioning method corresponding to the positioning accuracy requirement type is provided to the target railway user terminal to send the corresponding real-time positioning data to the target railway user terminal. The target positioning method includes: precise single-point positioning and real-time dynamic positioning method or real-time dynamic differential positioning method. Based on the reference conversion requirement type corresponding to the target railway user terminal, a corresponding real-time reference conversion service is provided to the target railway user terminal to send the corresponding real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can correct the real-time positioning data according to the real-time reference conversion data.

[0007] In some embodiments of this application, the railway user terminal adaptive positioning method further includes: If it is determined that the target railway user terminal is currently accessing the railway Beidou application service platform via web page access, then a post-data processing service based on a post-data processing method is provided to the target railway user terminal to send corresponding post-location service data to the target railway user terminal. The post-data processing method includes at least one of the following: seven-parameter conversion method, projection transformation method, precise single-point positioning method, post-processing dynamic differential method, and network adjustment method.

[0008] In some embodiments of this application, the railway user terminal adaptive positioning method further includes: If the railway Beidou application service platform receives an environment adaptive service instruction from a railway user terminal, it obtains the current environment scene type of the railway user terminal and searches for a positioning service strategy corresponding to the current environment scene type of the railway user terminal from a preset environment and technology association library. It then provides the target railway user terminal with an environment adaptive positioning service based on the positioning service strategy and sends the corresponding environment adaptive positioning service data to the target railway user terminal. The positioning service strategy includes at least one of the following: single base station positioning method, multi base station positioning method, virtual reference station positioning method, precise single point positioning method, and precise single point positioning and real-time dynamic positioning method.

[0009] In some embodiments of this application, the step of providing real-time positioning services based on the target positioning method corresponding to the positioning accuracy requirement type of the target railway user terminal, and sending corresponding real-time positioning data to the target railway user terminal, includes: If the positioning accuracy requirement type corresponding to the target railway user terminal is decimeter-level accuracy, then the real-time positioning data corresponding to the target railway user terminal is obtained by the precise single-point positioning and real-time dynamic positioning method, and the real-time positioning data is sent to the target railway user terminal.

[0010] In some embodiments of this application, the step of providing real-time positioning services based on the target positioning method corresponding to the positioning accuracy requirement type of the target railway user terminal, and sending corresponding real-time positioning data to the target railway user terminal, includes: If the positioning accuracy requirement type corresponding to the target railway user terminal is centimeter-level accuracy, then determine whether the current user coordinates of the target railway user terminal are located within the geographical range of any preset service area. If the user coordinates of the target railway user terminal are currently within the range of any preset service area, then the real-time dynamic differential positioning method corresponding to that service area is searched from the preset area and service association database. Based on the real-time dynamic differential positioning method, the real-time positioning data corresponding to the target railway user terminal is obtained and sent to the target railway user terminal. The area and service association database stores the correspondence between the geographical range of each service area and its corresponding real-time dynamic differential positioning method. The real-time dynamic differential positioning method includes: virtual reference station positioning method, single base station positioning method, or atmospheric enhancement single base station positioning method. If the user coordinates corresponding to the target railway user terminal are not within the range of any preset service area, then it is determined whether the distance between the target railway user terminal and the nearest base station is less than a distance threshold. If the distance between the target railway user terminal and the nearest base station is equal to or greater than the distance threshold, then the real-time positioning data corresponding to the target railway user terminal is obtained based on the virtual reference station positioning method and the real-time positioning data is sent to the target railway user terminal. If the distance between the target railway user terminal and the nearest base station is less than the distance threshold, then it is determined whether the elevation difference between the target railway user terminal and the nearest base station is less than the elevation difference threshold. If the distance between the target railway user terminal and the nearest base station is less than the elevation difference threshold, then based on the single base station positioning method, the real-time positioning data corresponding to the target railway user terminal is obtained from the nearest base station and the real-time positioning data is sent to the target railway user terminal. If the distance between the target railway user terminal and the nearest base station is equal to or greater than the elevation difference threshold, then based on the atmospheric enhancement single base station positioning method, the real-time positioning data corresponding to the target railway user terminal is obtained from the nearest base station and the real-time positioning data is sent to the target railway user terminal.

[0011] In some embodiments of this application, the step of providing a corresponding real-time reference conversion service to the target railway user terminal based on the reference conversion demand type corresponding to the target railway user terminal, and sending the corresponding real-time reference conversion data to the target railway user terminal, includes: If the benchmark conversion requirement type corresponding to the target railway user terminal includes elevation update requirement, then an elevation anomaly distribution map corresponding to the area range corresponding to the current location of the target railway user terminal is generated based on Kriging interpolation to obtain the elevation anomaly value of the current location of the target railway user terminal. Adjust the elevation anomalies to the elevation direction of the coordinate system where the virtual reference station is located; Obtain the projection values ​​of the elevation anomalies onto each pre-acquired satellite direction; The current observation data of the virtual reference station is corrected based on the projection value to obtain the corrected observation data; The corrected observation data is encoded to obtain encoded data; The encoded data is broadcast as real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can parse the corrected observation data from the encoded data and update the elevation data corresponding to the real-time positioning data based on the corrected observation data.

[0012] In some embodiments of this application, the step of providing a corresponding real-time reference conversion service to the target railway user terminal based on the reference conversion demand type corresponding to the target railway user terminal, and sending the corresponding real-time reference conversion data to the target railway user terminal, includes: If the reference transformation requirement type corresponding to the target railway user terminal includes virtual reference station coordinate transformation requirement, then multiple uniformly distributed coordinate points are constructed to represent the coordinate points to be transformed by seven parameters in the target coordinate system, wherein the target coordinate system includes a geographic coordinate system or a projected coordinate system. The original seven-parameter set is used to perform Bursa model transformation on each of the coordinate points to obtain the first transformed coordinate set; A new set of seven parameters is randomly generated, and a second Bursa model transformation is performed on each coordinate point in the first transformed coordinate set based on the new set of seven parameters to obtain a second transformed coordinate set. The residual matrices corresponding to the first and second transformed coordinate sets are fitted by the least squares method to obtain the pseudo-parameters corresponding to each coordinate point. The pseudo-parameters are injected into the Bursa model to perform encrypted transformation on the current coordinates of the virtual reference station; The coordinates of the virtual reference station after the encryption conversion and the pseudo-parameters are encapsulated and encrypted to obtain the corresponding encrypted data; The encrypted data is broadcast as real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can parse the pseudo-parameter from the encrypted data and perform coordinate conversion on the virtual reference station corresponding to the real-time positioning data based on the pseudo-parameter.

[0013] In some embodiments of this application, providing the target railway user terminal with a post-event data processing service based on a post-event data processing method to send corresponding post-event location service data to the target railway user terminal includes: If the post-event data processing method currently specified by the target railway user terminal includes the seven-parameter conversion method, then the seven-parameter conversion unit in the railway Beidou application service platform is invoked to generate seven-parameter conversion result data for the target railway user terminal, and the seven-parameter conversion result data is sent to the target railway user terminal as post-event positioning service data. If the post-processing method currently specified by the target railway user terminal includes projection transformation, then the projection transformation unit in the railway Beidou application service platform is invoked to generate projection transformation result data for the target railway user terminal, and the projection transformation result data is sent to the target railway user terminal as post-positioning service data. If the post-processing method currently specified by the target railway user terminal includes precise point positioning, then the precise point positioning unit in the railway Beidou application service platform is invoked to generate precise point positioning result data for the target railway user terminal, and the precise point positioning result data is sent to the target railway user terminal as post-processing positioning service data. If the post-processing data processing method currently specified by the target railway user terminal includes the post-processing dynamic differential method, then the post-processing dynamic differential unit in the railway Beidou application service platform is invoked to generate post-processing dynamic differential result data for the target railway user terminal, and the post-processing dynamic differential result data is sent to the target railway user terminal as post-location service data. If the post-processing method currently specified by the target railway user terminal includes network adjustment, then the network adjustment unit in the railway Beidou application service platform is invoked to generate network adjustment result data for the target railway user terminal, and the network adjustment result data is sent to the target railway user terminal as post-location service data.

[0014] Another aspect of this application provides an adaptive positioning system for railway user terminals, including a real-time service module set in a railway Beidou application service platform; The real-time service module includes: A real-time positioning service engine is used to provide real-time positioning services based on the target positioning method corresponding to the positioning accuracy requirement type of the target railway user terminal, and send corresponding real-time positioning data to the target railway user terminal if it is determined that the target railway user terminal is currently accessing the railway Beidou application service platform through terminal account login. The target positioning method includes: precise single-point positioning and real-time dynamic positioning method or real-time dynamic differential positioning method. The real-time reference conversion service engine is used to provide the target railway user terminal with the corresponding real-time reference conversion service according to the reference conversion requirement type of the target railway user terminal, and send the corresponding real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can correct the real-time positioning data according to the real-time reference conversion data.

[0015] In some embodiments of this application, the railway user terminal adaptive positioning system further includes a post-service module and an environmental adaptive service module, both of which are set in the railway Beidou application service platform. The post-event service module includes: The post-event data processing service engine is used to provide post-event data processing services based on the post-event data processing method to the target railway user terminal if it is determined that the current access method of the target railway user terminal to the railway Beidou application service platform is web page access. The post-event data processing method includes at least one of the following: seven-parameter conversion method, projection transformation method, precise single-point positioning method, post-processing dynamic differential method, and network adjustment method. The environment adaptive service module is used to obtain the current environment scene type of the railway user terminal if it receives an environment adaptive service instruction from the railway user terminal in the railway Beidou application service platform, and search for the positioning service strategy corresponding to the current environment scene type of the railway user terminal from the preset environment and technology association library, and provide the target railway user terminal with environment adaptive positioning service based on the positioning service strategy to send the corresponding environment adaptive positioning service data to the target railway user terminal. The positioning service strategy includes at least one of the following: single base station positioning method, multi base station positioning method, virtual reference station positioning method, precise single point positioning method, and precise single point positioning and real-time dynamic positioning method.

[0016] A third aspect of this application provides an electronic 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 railway user terminal adaptive positioning method described above.

[0017] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the aforementioned adaptive positioning method for railway user terminals.

[0018] A fifth aspect of this application provides a computer program product, including a computer program that, when executed by a processor, implements the aforementioned railway user terminal adaptive positioning method.

[0019] The adaptive positioning method for railway user terminals provided in this application, if it is determined that the current access method of the target railway user terminal to the railway Beidou application service platform is terminal account login access, then according to the positioning accuracy requirement type corresponding to the target railway user terminal, provides the target railway user terminal with a real-time positioning service based on the target positioning method corresponding to the positioning accuracy requirement type, and sends the corresponding real-time positioning data to the target railway user terminal. The target positioning method includes: precise single-point positioning and real-time dynamic positioning or real-time dynamic differential positioning. According to the reference conversion requirement type corresponding to the target railway user terminal, it provides the target railway user terminal with a corresponding real-time reference conversion service and sends the corresponding real-time reference conversion data to the target railway user terminal. This allows the target railway user terminal to correct the real-time positioning data based on the real-time reference conversion data. This method can provide high-precision adaptive elastic positioning services for railway user terminals based on the railway Beidou application service platform, and can integrate multiple positioning methods, thereby effectively improving the positioning accuracy, dynamic adaptability, reliability, and effectiveness of railway user terminals, and effectively improving the reliability and stability of railway operations.

[0020] Additional advantages, objectives, and features of this application will be set forth in part in the description which follows, and will in part become apparent to those skilled in the art upon review of the following description, or may be learned by practice of the application. The objectives and other advantages of this application can be realized and obtained by means of the structures specifically pointed out in the specification and drawings.

[0021] Those skilled in the art will understand that the purposes and advantages that can be achieved with this application are not limited to those specifically described above, and that the above and other purposes that this application can achieve will be more clearly understood from the following detailed description. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, do not constitute a limitation thereof. The components in the drawings are not drawn to scale but are merely for illustrating the principles of this application. For ease of illustration and description of certain parts of this application, corresponding portions in the drawings may be enlarged, i.e., may appear larger relative to other components in an exemplary system actually manufactured according to this application. In the drawings: Figure 1 This is a schematic diagram of the first process of the adaptive positioning method for railway user terminals in one embodiment of this application.

[0023] Figure 2 This is a schematic diagram of a second process of the adaptive positioning method for railway user terminals in one embodiment of this application.

[0024] Figure 3 This is a technical roadmap of the adaptive positioning method for railway user terminals in one embodiment of this application.

[0025] Figure 4 This is a flowchart illustrating step 100 in the adaptive positioning method for railway user terminals according to an embodiment of this application.

[0026] Figure 5 This is a technical roadmap for the real-time positioning service with centimeter-level accuracy in step 100 of the adaptive positioning method for railway user terminals in one embodiment of this application.

[0027] Figure 6 This is a flowchart illustrating step 200 in the adaptive positioning method for railway user terminals according to an embodiment of this application.

[0028] Figure 7 This is a flowchart illustrating step 300 in the adaptive positioning method for railway user terminals according to an embodiment of this application.

[0029] Figure 8 This is a schematic diagram of the first structure of the adaptive positioning system for railway user terminals in one embodiment of this application.

[0030] Figure 9 This is a schematic diagram of a second structure of the adaptive positioning system for railway user terminals in one embodiment of this application. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and their descriptions are used to explain this application, but are not intended to limit it.

[0032] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the structures and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0033] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0034] It should also be noted that, unless otherwise specified, the term "connection" in this article can refer not only to a direct connection, but also to an indirect connection involving an intermediary.

[0035] In the following description, embodiments of the present application will be illustrated with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar parts, or the same or similar steps.

[0036] To address the current problem that railway positioning services only provide a single ground-based augmentation service, lacking satellite-based and satellite-ground fusion services, which leads to the inability to guarantee the positioning accuracy, dynamic adaptability, and reliability of railway user terminals, this application provides a railway user terminal adaptive positioning method, a railway user terminal adaptive positioning system for executing the railway user terminal adaptive positioning method, physical equipment, a computer-readable storage medium, and a computer program product. This enables various high-precision location services to provide more reliable and effective positioning services to different railway user terminals through a unified platform.

[0037] The following examples will provide a detailed description.

[0038] Based on this, embodiments of this application provide an adaptive positioning method for railway user terminals that can be implemented by a railway user terminal adaptive positioning system, see [link to relevant documentation]. Figure 1 The adaptive positioning method for railway user terminals specifically includes the following: Step 100: If it is determined that the current access method of the target railway user terminal to the railway Beidou application service platform is terminal account login access, then according to the positioning accuracy requirement type corresponding to the target railway user terminal, provide the target railway user terminal with real-time positioning service based on the target positioning method corresponding to the positioning accuracy requirement type to send the corresponding real-time positioning data to the target railway user terminal. The target positioning method includes: precise single-point positioning and real-time dynamic positioning method or real-time dynamic differential positioning method.

[0039] Among them, the target railway user terminal refers to the railway user terminal currently connected to the railway Beidou application service platform. The railway user terminal may include communication terminals, positioning terminals or receivers on railway trains or vehicles running to the preset railway coverage area, and may also include mobile client terminals on railway trains or in the preset railway coverage area. The specific configuration can be set according to actual service needs.

[0040] Understandably, the Railway BeiDou Application Service Platform is a software system that provides high-precision location services, communication services, timing services, on-network equipment management services, operation management services, and encryption / decryption services for various professional business applications throughout the entire railway lifecycle. With the gradual deepening application of BeiDou technology in the railway industry, to ensure the accuracy, stability, and availability of BeiDou spatiotemporal information services, promote the interconnection and interoperability of spatiotemporal information and big data analysis, research has been conducted on key technologies such as: a high-precision location service calculation method for the entire railway network based on spatial error information correction; high-precision calculation and broadcasting services adapted to internal and external railway service networks; data fusion processing of the BeiDou high-precision location service network based on multi-network integration; and visualization display of on-network terminals based on a single geographic information map and optimization methods for core components. These advancements have improved the platform's location service accuracy, coverage, and stability, enabled efficient storage, scheduling, display, and sharing of spatiotemporal data, facilitated the construction of a systematic BeiDou demonstration application, and enhanced the comprehensive service level of railway spatiotemporal information.

[0041] The railway user terminal adaptive positioning system can be a software functional module within the railway BeiDou application service platform. It can communicate and connect with other software functional modules within the platform to directly interact with existing services. In step 100, when the railway user terminal adaptive positioning system detects or is notified by other software functional modules of the railway BeiDou application service platform that a new railway user terminal is accessing the platform, it identifies that railway user terminal as the current target railway user terminal and obtains its access method. If the target railway user terminal's current access method is determined to be terminal account login, then real-time positioning services are provided to it.

[0042] It is understandable that when a railway user terminal accesses the railway Beidou application service platform, it will simultaneously upload its own associated data, such as the current location information (positioning data), GNSS observation data, environmental sensor data, and reference station data. The specific data types can be set according to the service type of the railway Beidou application service platform specified in advance by the railway user terminal. That is, after the first registration or modification and update of settings, the railway user terminal will upload the associated data required for adaptive positioning by default every time it accesses the railway Beidou application service platform.

[0043] It is understood that positioning accuracy requirements can include decimeter-level accuracy, centimeter-level accuracy, and meter-level accuracy, etc. Since the scenario in this application is a high-precision location service scenario, differentiated flexible positioning settings are mainly implemented for decimeter-level and centimeter-level accuracy requirements. The decimeter-level and centimeter-level accuracy correspond to different target positioning methods, for example: the decimeter-level accuracy corresponds to precise single-point positioning and real-time dynamic positioning methods; the centimeter-level accuracy corresponds to real-time dynamic differential positioning.

[0044] In one or more embodiments of this application, the precision point positioning and real-time dynamic positioning method PPP-RTK corresponding to decimeter-level accuracy refers to the combination of two technologies: precision point positioning (PPP) and real-time dynamic differential positioning (RTK). It has the advantages of both technologies, and features high accuracy, short convergence time, wide coverage, and short initialization time.

[0045] Precise Point Positioning (PPP), often abbreviated as PPP, collects data from various sensors, including satellite position and velocity information, as well as receiver observation data. It then processes the data using noise filtering and data computation methods, leveraging high-precision satellite ephemeris and clock bias products provided by organizations such as the Global Navigation Satellite System (GNSS) Service Organization (IGS) to precisely correct various error terms. Ultimately, it achieves decimeter-level positioning using a single receiver. PPP's advantages lie in its high accuracy and wide coverage, but its algorithm performance is relatively low, resulting in slow convergence speed.

[0046] Real-Time Kinematic (RTK) positioning employs a carrier phase differential method. First, both the base station and the vehicle simultaneously observe satellite carrier signals. The base station broadcasts its observations via radio. After receiving the signal from the base station, the vehicle subtracts its own observations to eliminate shared errors, thus accurately determining the spatial relative position between the vehicle and the base station. This relative position is then converted into the coordinates required by the user. The advantage of RTK lies in the real-time transmission of corrections through the communication link between the base station and the vehicle, significantly improving convergence speed. However, a disadvantage is that accuracy is only maintained for 30 seconds after corrections are lost.

[0047] The Precise Point Positioning (PPP) and Real-Time Kinematic (RTK) approach unifies Precise Point Positioning (PPP) and Real-Time Kinematic (RTK) at the algorithm level, combining the advantages of both while mitigating their disadvantages. In this technology, the PPP component corrects for satellite orbit clock errors and phase deviations, achieving centimeter-level high-precision enhancement based on satellite data. Initialization can be completed within 2 minutes, significantly reducing processing time. The RTK component adjusts the sampling frequency based on different base station densities and bandwidths, avoiding the effects of ionospheric and tropospheric delays. After correction data loss, the accuracy retention time increases to 120 seconds. Furthermore, it requires relatively low base station density and has extremely low dependence on individual base stations.

[0048] The real-time location data refers to data used to indicate current location information. In one example, the real-time location data may specifically include: (1) Positioning coordinate data: such as three-dimensional coordinates and accuracy indicators. Three-dimensional coordinates can include latitude and longitude (WGS-84 or local coordinate system) and elevation (ellipsoidal height or orthographic height) or plane projection coordinates.

[0049] (2) Satellite observation data: such as carrier phase observations and Doppler frequency data.

[0050] (3) Differential correction data: such as satellite clock error correction, satellite orbit error correction (comparison of broadcast ephemeris and precise ephemeris) and other reference station correction parameters, as well as ionospheric delay correction (dual-frequency / multi-frequency combination to eliminate first-order error) and tropospheric wet delay model parameters, and may also include transmission protocols.

[0051] (4) Positioning status and quality indicators: such as solution status flags, data quality parameters and multipath effect indicators (MP1 / MP2), etc.; solution status flags may include fixed solution (Fix, highest accuracy), floating solution (Float, lower accuracy) and single solution (Single) first-level ambiguity fixation success rate (≥95% is high-quality data), etc.; data quality parameters may include signal-to-noise ratio (SNR) reflecting satellite signal strength, etc.

[0052] (5) Time and dynamic information: such as timestamps and velocity and acceleration; timestamps can be synchronized with the base station and rover data using GNSS system time (such as GPS week second, Beidou time); velocity and acceleration can be calculated by carrier phase change rate to obtain the rover's real-time velocity (accuracy 0.03 m / s) and acceleration.

[0053] (6) Environmental and system parameters: such as satellite system information and base station identifier; satellite system information may include the satellite systems involved in the calculation (GPS, BeiDou, GNSS) and the number of visible satellites (≥12 for ideal conditions) and the spatial geometric distribution of satellites (Position Dilution of Precision (PDOP) value, ≤2 for high precision). Base station identifier may include base station ID, coordinates, and data transmission frequency, etc.

[0054] It should be noted that in this application, real-time location data can also be written as real-time location correction data or real-time location correction data, which means that the railway user terminal can correct the latest local location information in real time based on the received real-time location data.

[0055] It should be noted that step 100 can adaptively provide real-time dynamic differential positioning (RTK) or PPP-RTK service that integrates ground-based and satellite-based positioning according to user needs. However, providing a flexible and adaptive real-time positioning service for railway user terminals can only guarantee their positioning accuracy to a certain extent. If the consistency of positioning across systems cannot be guaranteed, various positioning-related errors, such as elevation errors, will still occur. Therefore, in step 200 below in this application, a corresponding real-time reference conversion service is further provided to the target railway user terminal, and the real-time reference conversion service is adaptively provided according to the reference conversion requirement type.

[0056] Step 200: Based on the reference conversion requirement type corresponding to the target railway user terminal, provide the target railway user terminal with the corresponding real-time reference conversion service to send the corresponding real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can correct the real-time positioning data according to the real-time reference conversion data.

[0057] It is understandable that the benchmark transformation requirement type may include elevation update requirements and / or virtual reference station coordinate transformation requirements, which can be executed according to the instructions issued by the railway user terminal when accessing the railway Beidou application service platform or the preset default service data.

[0058] Real-time reference transformation data may include encrypted data corresponding to the coordinates and pseudo-parameters of the virtual reference station after encryption transformation, and may also include encoded data corresponding to the observation data of the corrected virtual reference station (VRS) (which can be simply referred to as VRS observation data).

[0059] As can be seen from the above description, the railway user terminal adaptive positioning method provided in this application embodiment can provide high-precision adaptive elastic positioning services for railway user terminals based on the railway Beidou application service platform, and can integrate multiple positioning methods, thereby effectively improving the positioning accuracy, dynamic adaptability, reliability and effectiveness of railway user terminals.

[0060] To further improve the effectiveness and applicability of adaptive positioning for railway user terminals, an adaptive positioning method for railway user terminals is provided in this application embodiment, see [link to relevant documentation]. Figure 2 The adaptive positioning method for railway user terminals also includes the following: Step 300: If it is determined that the target railway user terminal is currently accessing the railway Beidou application service platform via web page access, then provide the target railway user terminal with post-data processing services based on post-data processing methods to send the corresponding post-location service data to the target railway user terminal. The post-data processing methods include at least one of the following: seven-parameter conversion method, projection transformation method, precise single-point positioning method, post-processing dynamic differential method, and network adjustment method.

[0061] In other words, if it is determined that the target railway user terminal is currently accessing the railway Beidou application service platform through a webpage, then a post-event data processing service based on the post-event data processing method will be provided to the target railway user terminal.

[0062] To further improve the accuracy and reliability of adaptive positioning for railway user terminals, an adaptive positioning method for railway user terminals is provided in an embodiment of this application, see [link to relevant documentation]. Figure 2 and Figure 3 The adaptive positioning method for railway user terminals also includes the following: Step 400: If an environment adaptive service instruction is received from a railway user terminal in the railway Beidou application service platform, the current environment scene type of the railway user terminal is obtained, and a positioning service strategy corresponding to the current environment scene type of the railway user terminal is searched from the preset environment and technology association library. The target railway user terminal is provided with an environment adaptive positioning service based on the positioning service strategy to send the corresponding environment adaptive positioning service data to the target railway user terminal. The positioning service strategy includes at least one of the following: single base station positioning method, multi base station positioning method, virtual reference station positioning method, precise single point positioning method, and precise single point positioning and real-time dynamic positioning method.

[0063] Specifically, before executing step 400, the positioning accuracy and efficiency of single-base station positioning, multi-base station positioning, virtual reference station positioning, precise single-point positioning, and precise single-point positioning combined with real-time dynamic positioning can be tested in different railway construction site environments (mountains, canyons, rivers, tunnel entrances, bridges). The optimal service strategy for each scenario is statistically analyzed, and an environment and technology association library (i.e., a database) containing the correspondence between environmental scenario types and positioning service strategies is generated. The environmental scenario type refers to the construction site environment attributes, such as mountains, canyons, rivers, tunnel entrances, and bridges. The positioning service strategy may include single-base station positioning, multi-base station positioning, virtual reference station positioning, precise single-point positioning, and precise single-point positioning combined with real-time dynamic positioning, as well as their corresponding performance indicators.

[0064] In one example, PPP-RTK service (anti-multipath level ≥ 4) is prioritized for environmental scenarios such as tunnel entrances or bridges; atmospheric correction single base station service (elevation compensation mode) can be enabled for environmental scenarios such as high mountains or canyons.

[0065] Then, the platform deploys data service access points and environment adaptive service access points corresponding to single base station positioning, multi base station positioning, virtual reference station positioning, precise single point positioning, and precise single point positioning and real-time dynamic positioning. The environment adaptive service instruction received from the railway user terminal in step 400 can instruct the user to access the environment adaptive service access point.

[0066] The corresponding environmental adaptive positioning service data sent to the target railway user terminal can be differential correction data, etc. Then, the correction data can be binary encoded using the RTCM protocol to generate a 30-bit message field containing a parity check code, which is then transmitted to the target railway user terminal via an asynchronous serial port.

[0067] To further improve the flexibility and effectiveness of decimeter-level accuracy in real-time positioning services for railway user terminals, an adaptive positioning method for railway user terminals is provided in this application embodiment. (See also...) Figure 4 Step 100 in the railway user terminal adaptive positioning method specifically includes the following: Step 110: If it is determined that the current access method of the target railway user terminal to the railway Beidou application service platform is terminal account login access, and if the positioning accuracy requirement type corresponding to the target railway user terminal is decimeter-level accuracy, then the real-time positioning data corresponding to the target railway user terminal is obtained by the precise single-point positioning and real-time dynamic positioning method and the real-time positioning data is sent to the target railway user terminal.

[0068] In one example, correction information for the ionosphere, troposphere, and orbit can be sent via precise point positioning and real-time dynamic positioning PPP-RTK services.

[0069] To further improve the flexibility and effectiveness of centimeter-level services in real-time positioning services for railway user terminals, an adaptive positioning method for railway user terminals is provided in this application embodiment. (See also...) Figure 4 and Figure 5 Step 100 in the railway user terminal adaptive positioning method specifically includes the following: Step 120: If it is determined that the target railway user terminal is currently accessing the railway Beidou application service platform via terminal account login, and if the positioning accuracy requirement type corresponding to the target railway user terminal is centimeter-level accuracy, then determine whether the user coordinates corresponding to the target railway user terminal are located within the geographical range of any preset service area; if yes, then proceed to step 130; otherwise, then proceed to step 140.

[0070] Step 130: Search for the real-time dynamic differential positioning method corresponding to the service area in the preset area and service association database, obtain the real-time positioning data corresponding to the target railway user terminal based on the real-time dynamic differential positioning method, and send the real-time positioning data to the target railway user terminal; wherein, the area and service association database is used to store the correspondence between the geographical range of each service area and its corresponding real-time dynamic differential positioning method; wherein, the real-time dynamic differential positioning method includes: virtual reference station positioning method, single base station positioning method, or atmospheric enhancement single base station positioning method.

[0071] Step 130 can be referred to as the associated database location service.

[0072] Step 140: Determine whether the distance between the target railway user terminal and the nearest base station is less than the distance threshold. If not, proceed to step 150; if yes, proceed to step 160.

[0073] The distance threshold can be set according to the actual application requirements. In one example, the distance threshold can be set to 2KM (kilometers).

[0074] Step 150: Obtain the real-time positioning data corresponding to the target railway user terminal based on the virtual reference station positioning method and send the real-time positioning data to the target railway user terminal.

[0075] Understandably, Virtual Reference Station (VRS) positioning is a form of network RTK. Through multi-reference station networking and real-time error modeling, a virtual reference station is dynamically generated near the rover, providing centimeter-level high-precision positioning services. Its core lies in using a regionalized error correction model to replace the local corrections of traditional single-base station RTK, improving coverage and anti-interference capabilities.

[0076] Step 160: Determine whether the elevation difference between the target railway user terminal and the nearest base station is less than the elevation difference threshold. If yes, proceed to step 170; otherwise, proceed to step 180.

[0077] The elevation difference threshold can be set according to actual application requirements. In one example, the elevation difference threshold can be set to 200M (meters).

[0078] Step 170: Based on the single base station positioning method, obtain the real-time positioning data corresponding to the target railway user terminal from the nearest base station and send the real-time positioning data to the target railway user terminal.

[0079] Understandably, single-base station positioning is an implementation of RTK (Real-Time Kinematic) technology. It provides real-time differential correction data to the rover based on a single base station, achieving centimeter-level high-precision positioning. Its core characteristic is that it relies on a single base station to complete error modeling and transmission, without requiring multi-base station collaboration or network RTK support.

[0080] Step 180: Based on the atmospheric enhancement single base station positioning method, obtain the real-time positioning data corresponding to the target railway user terminal from the nearest base station and send the real-time positioning data to the target railway user terminal.

[0081] Understandably, atmospheric-enhanced single-base station positioning is a high-precision positioning method based on single-base station RTK technology. It improves positioning accuracy and stability by introducing a real-time atmospheric error correction model. Its core principle is: single-base station differential correction and atmospheric error enhancement. Base station differential correction refers to the base station calculating satellite signal errors (such as orbital errors and clock errors) in real time using known coordinates and sending the differential correction data to the rover via a wireless network. After receiving the correction data, the rover combines it with its own observations to eliminate common errors, achieving centimeter-level positioning accuracy. Atmospheric error enhancement refers to using atmospheric parameters such as ionospheric delay and tropospheric humidity monitored in real time by the base station to construct a regionalized atmospheric error model. This model is then superimposed with atmospheric correction parameters on top of the differential correction, further reducing positioning drift caused by meteorological changes (e.g., horizontal errors can be controlled within ±2cm).

[0082] To further improve the flexibility and reliability of real-time reference conversion services for railway user terminals, an adaptive positioning method for railway user terminals is provided in this application embodiment. (See also...) Figure 6 Step 200 in the adaptive positioning method for railway user terminals specifically includes the following: Step 211: If the benchmark conversion requirement type corresponding to the target railway user terminal includes elevation update requirement, then generate an elevation anomaly distribution map corresponding to the area range where the target railway user terminal is currently located based on Kriging interpolation, so as to obtain the elevation anomaly value of the target railway user terminal's current location.

[0083] Kriging interpolation is a geostatistical method based on regionalized variable theory. It analyzes the spatial correlation between data points to construct an optimal unbiased estimation model for predicting attribute values ​​of unknown points. Its core feature is combining the spatial distribution patterns and statistical characteristics of sample points to achieve high-precision spatial interpolation.

[0084] A geoid undulation map is a spatial distribution map used to visualize the systematic deviation between actual elevations and theoretical elevation models. It mainly reflects local errors or regional differences in topographic data or gravity field models that have not been completely eliminated. For example, when generating a digital elevation model (DEM) based on Kriging interpolation, this geoid undulation map can identify residual areas between the interpolation results and measured points.

[0085] Step 212: Adjust the elevation anomaly value to the elevation direction of the coordinate system where the virtual reference station is located.

[0086] The coordinate system of the virtual reference station can refer to the geocentric-fixed coordinate system (ECEF), that is, a right-handed Cartesian coordinate system with the origin at the Earth's center of mass, the X-axis pointing to the intersection of the prime meridian and the equator, the Z-axis pointing to the North Pole, and the Y-axis perpendicular to the XZ plane, forming a three-dimensional rectangular coordinate system.

[0087] Step 213: Obtain the projection values ​​of the elevation anomalies in each of the pre-acquired satellite directions.

[0088] Specifically, the projection of a geoid onto a satellite axis refers to the decomposition of the geoid (the vertical deviation from the geoid to the ellipsoid) along the pre-acquired satellite observation direction, reflecting the geometric components of the geoid along a specific line-of-sight (LOS) direction. This projection value is often used to analyze the spatial impact of geoids on satellite altimetry, InSAR deformation monitoring, and other data. InSAR (Interferometric Synthetic Aperture Radar) is a remote sensing technique that uses the phase difference of synthetic aperture radar (SAR) images to detect surface deformation and elevation information.

[0089] Step 214: Correct the current observation data of the virtual reference station according to the projection value to obtain the corrected observation data.

[0090] Step 215: Encode the corrected observation data to obtain encoded data.

[0091] Step 216: Broadcast the encoded data as real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can parse the corrected observation data from the encoded data and update the elevation data corresponding to the real-time positioning data based on the corrected observation data.

[0092] To further improve the flexibility and reliability of real-time reference conversion services for railway user terminals, an adaptive positioning method for railway user terminals is provided in this application embodiment. (See also...) Figure 6 Step 200 in the adaptive positioning method for railway user terminals specifically includes the following: Step 221: If the reference transformation requirement type corresponding to the target railway user terminal includes virtual reference station coordinate transformation requirement, then construct multiple uniformly distributed coordinate points in the target coordinate system to be transformed by seven parameters, wherein the target coordinate system includes a geographic coordinate system or a projected coordinate system.

[0093] Understandably, the seven parameters are key parameters for transforming a spatial rectangular coordinate system. The seven parameters include three translation parameters: △X, △Y, and △Z, which represent the translation of the origin of the target coordinate system relative to the original coordinate system in the X, Y, and Z axes, respectively; the seven parameters also include three rotation parameters: △α, △β, and △γ, which represent the rotation angles around the X, Y, and Z axes, respectively, and the coordinate axes of the two coordinate systems are aligned by rotating in sequence; the seven parameters also include a scale factor K, which represents the proportional relationship of the same length between the two coordinate systems, and is usually close to 1 (e.g., K=1.000005).

[0094] Step 222: Perform Bursa model transformation on each of the coordinate points using the original seven-parameter set to obtain the first transformed coordinate set.

[0095] Understandably, the Bursa-Wolf model is a seven-parameter spatial coordinate transformation model used to achieve high-precision transformation between different three-dimensional Cartesian coordinate systems (such as WGS84 and Beijing 54 coordinate system); the first transformation coordinate set can be written as {aa}.

[0096] Step 223: Randomly generate a new seven-parameter set, and perform a second Bursa model transformation on each of the coordinate points in the first transformed coordinate set based on the new seven-parameter set to obtain the second transformed coordinate set.

[0097] The second transformed coordinate set can be written as {bb}.

[0098] Step 224: Fit the residual matrices corresponding to the first transformed coordinate set and the second transformed coordinate set using the least squares method to obtain the pseudo-parameters corresponding to each coordinate point.

[0099] The pseudo-parameter can be denoted as B.

[0100] Step 225: Inject the pseudo-parameters into the Bursa model to perform encrypted transformation on the current coordinates of the virtual reference station.

[0101] Step 226: Encapsulate and encrypt the coordinates of the virtual reference station after the encryption conversion and the pseudo-parameters to obtain the corresponding encrypted data.

[0102] Step 227: Broadcast the encrypted data as real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can parse the pseudo-parameter from the encrypted data and perform coordinate conversion on the virtual reference station corresponding to the real-time positioning data based on the pseudo-parameter.

[0103] To further improve the flexibility and reliability of post-event positioning services for railway user terminals, an adaptive positioning method for railway user terminals is provided in this application embodiment. (See also...) Figure 7 Step 300 in the adaptive positioning method for railway user terminals specifically includes the following: Step 310: If it is determined that the target railway user terminal is currently accessing the railway Beidou application service platform via web page access, then obtain the post-processing method indicated by the target railway user terminal.

[0104] Step 320: If the post-processing method currently specified by the target railway user terminal includes the seven-parameter conversion method, then the seven-parameter conversion unit in the railway Beidou application service platform is invoked to generate the seven-parameter conversion result data for the target railway user terminal, and the seven-parameter conversion result data is sent to the target railway user terminal as post-location service data.

[0105] The seven-parameter transformation (Bursha-Wolf model) is a mathematical model for the transformation of three-dimensional rectangular coordinate systems. It achieves high-precision alignment of different reference coordinate systems (such as WGS84 and Beijing 54 coordinate system) through seven parameters, as described in steps 221 to 227 above.

[0106] Step 330: If the post-processing method currently specified by the target railway user terminal includes projection transformation, then the projection transformation unit in the railway Beidou application service platform is invoked to generate projection transformation result data for the target railway user terminal, and the projection transformation result data is sent to the target railway user terminal as post-positioning service data.

[0107] Step 340: If the post-processing method currently specified by the target railway user terminal includes precise point positioning, then the precise point positioning unit in the railway Beidou application service platform is invoked to generate precise point positioning result data for the target railway user terminal, and the precise point positioning result data is sent to the target railway user terminal as post-processing positioning service data.

[0108] Step 350: If the post-processing data processing method currently specified by the target railway user terminal includes the post-processing dynamic differential method, then the post-processing dynamic differential unit in the railway Beidou application service platform is invoked to generate post-processing dynamic differential result data for the target railway user terminal, and the post-processing dynamic differential result data is sent to the target railway user terminal as post-location service data.

[0109] Step 360: If the post-processing method currently specified by the target railway user terminal includes network adjustment, then the network adjustment unit in the railway Beidou application service platform is invoked to generate network adjustment result data for the target railway user terminal, and the network adjustment result data is sent to the target railway user terminal as post-location service data.

[0110] From a software perspective, this application also provides a railway user terminal adaptive positioning system for executing all or part of the aforementioned railway user terminal adaptive positioning method, see [link to relevant documentation]. Figure 8 The railway user terminal adaptive positioning system specifically includes a real-time service module 10 set in the railway Beidou application service platform, and the real-time service module 10 specifically includes the following: The real-time positioning service engine 11 is used to provide real-time positioning services based on the target positioning method corresponding to the positioning accuracy requirement type to the target railway user terminal if it is determined that the current access method of the target railway user terminal to the railway Beidou application service platform is terminal account login access. The engine then sends the corresponding real-time positioning data to the target railway user terminal. The target positioning method includes: precise single-point positioning and real-time dynamic positioning method or real-time dynamic differential positioning method.

[0111] The real-time reference conversion service engine 12 is used to provide the target railway user terminal with the corresponding real-time reference conversion service according to the reference conversion requirement type of the target railway user terminal, and send the corresponding real-time reference conversion data to the target railway user terminal, so that the target railway user terminal corrects the real-time positioning data according to the real-time reference conversion data.

[0112] The embodiments of the railway user terminal adaptive positioning system provided in this application can be used to execute the processing flow of the embodiments of the railway user terminal adaptive positioning method in the above embodiments. Its functions will not be repeated here, but can be referred to the detailed description of the embodiments of the railway user terminal adaptive positioning method in the above embodiments.

[0113] The adaptive positioning system for railway user terminals described herein can perform the adaptive positioning function on either a server or a client device. The choice can be made based on the processing capabilities of the client device and the limitations of the user's usage scenario. This application does not impose any limitations in this regard. If all operations are performed on the client device, the client device may further include a processor for the specific processing of the adaptive positioning of the railway user terminal.

[0114] The aforementioned client device may have a communication module (i.e., a communication unit) that can communicate with a remote server to achieve data transmission. The server may include a server on the task scheduling center side; in other implementation scenarios, it may also include a server on an intermediate platform, such as a server on a third-party server platform that has a communication link with the task scheduling center server. The server may include a single computer device, a server cluster consisting of multiple servers, or a distributed system server structure.

[0115] The server and the client device can communicate using any suitable network protocol, including those not yet developed as of the date of this application. Such network protocols may include, for example, TCP / IP, UDP / IP, HTTP, HTTPS, etc. Furthermore, such network protocols may also include RPC (Remote Procedure Call Protocol) and REST (Representational State Transfer Protocol) protocols used on top of the aforementioned protocols.

[0116] As can be seen from the above description, the railway user terminal adaptive positioning system provided in this application embodiment can provide high-precision adaptive elastic positioning services for railway user terminals based on the railway Beidou application service platform, and can integrate multiple positioning methods, thereby effectively improving the positioning accuracy, dynamic adaptability, reliability and effectiveness of railway user terminals.

[0117] To further improve the effectiveness and applicability of adaptive positioning for railway user terminals, an adaptive positioning system for railway user terminals is provided in an embodiment of this application, see [link to relevant documentation]. Figure 9 The railway user terminal adaptive positioning system also includes a post-event service module 20 and an environment adaptive service module 30, both of which are installed in the railway Beidou application service platform; the post-event module 20 specifically includes the following: The post-event data processing service engine 21 is used to provide post-event data processing services based on the post-event data processing method to the target railway user terminal if it is determined that the current access method of the target railway user terminal to the railway Beidou application service platform is web page access. The post-event data processing method includes at least one of the following: seven-parameter conversion method, projection transformation method, precise single-point positioning method, post-processing dynamic differential method, and network adjustment method.

[0118] The environment adaptive service module 30 is used to obtain the current environment scene type of the railway user terminal if it receives an environment adaptive service instruction from the railway user terminal in the railway Beidou application service platform, and search for the positioning service strategy corresponding to the current environment scene type of the railway user terminal from the preset environment and technology association library, and provide the target railway user terminal with environment adaptive positioning service based on the positioning service strategy to send the corresponding environment adaptive positioning service data to the target railway user terminal. The positioning service strategy includes at least one of the following: single base station positioning method, multi base station positioning method, virtual reference station positioning method, precise single point positioning method, and precise single point positioning and real-time dynamic positioning method.

[0119] To further illustrate the above embodiments, this application also provides a specific application example of an adaptive positioning method for railway user terminals executed by an adaptive positioning system for railway user terminals set in a railway Beidou application service platform. For high-precision location services, these are mainly divided into two categories: ground-based and satellite-based. Ground-based RTK services include single-base station RTK real-time and post-service, and ground-based augmentation system real-time and post-service. Satellite-based services include satellite-based augmentation system services and precise point positioning services. There are also satellite-based fusion PPP-RTK services that combine ground and satellite technologies. Real-time services based on ground-based augmentation systems include network RTK, virtual reference station (VRS), and grid reference station services. This application example provides more suitable services for different railway user terminals, different scenarios, and different environments through a unified platform.

[0120] Based on this, for high-precision location service technology, services are integrated based on the railway Beidou application service platform. According to the technical characteristics of each service and the needs of railway user terminals such as environment, scenario and business, the service mounting point of the platform is automatically switched to achieve service self-adaptation. This application proposes a high-precision location service adaptive service strategy for complex railway environments. This strategy is the basis for judging the automatic switching of service mounting points.

[0121] Specifically, the application examples in this application include the following: (I) Adaptive Strategies Based on Elastic Fusion Location Service Technology Architecture Based on user requirements for positioning accuracy, real-time performance, and positioning reference, a flexible fusion positioning service is achieved through a real-time positioning service engine, a real-time reference conversion engine, and a post-processing data engine. This service, relying on the railway BeiDou application service platform, provides adaptive high-precision location services for users in multiple railway scenarios. The platform determines service real-time performance based on user access methods. For users accessing websites, post-processing services are provided, utilizing the post-processing data engine based on user data processing needs. For users accessing positioning terminals, the platform utilizes both the real-time positioning service engine and the real-time reference conversion engine to provide services based on the user's positioning accuracy type and reference requirements.

[0122] (II) Real-time Location Service Engine Technology Process The real-time location service engine aims to provide high-precision and flexible location services, adapting to different terminal account types and operational needs, achieving centimeter-level and decimeter-level positioning accuracy, and meeting the needs of multiple scenarios and types of users.

[0123] (1) The elastic service embodied by the real-time location service engine includes two aspects: Flexibility 1: Provide positioning services with varying levels of precision based on user needs. Centimeter-level users: Utilize ground-based augmentation services to generate virtual corrections using the Continuously Operating Reference Stations (CORS) system and send them to the terminal. Decimeter-level users: Send ionospheric, tropospheric, and orbital correction information via precise point positioning and real-time dynamic positioning (PPP-RTK) services.

[0124] Elasticity 2: Automatic switching of service types. Enables automatic switching of multiple modes (Virtual Reference Station (VRS) service mode, single base station service mode, and atmospheric correction single base station service mode) in centimeter-level services.

[0125] (2) The technical implementation of the real-time location service engine is as follows: a. Establish a database linking services and regional attributes, specifically as follows: Step 1: Conduct a precision comparison experiment of various service models in key construction areas.

[0126] Step 2: Based on the experimental results, establish an index relationship between the work area and the optimal service type.

[0127] Step 3: Associate the service with the region's attributes and store them in the database to provide users with universal services.

[0128] b. Service mode switching logic: Step 1: Determine if the user's location is in the associated database, specifically: ① Use topological relationship judgment technology to check whether the user's coordinates are within the service area defined by the associated library.

[0129] ② If within the associated region, directly provide matching service technology.

[0130] Step 2: Determine the nearest base stations to the user's location, specifically: ① If the user is not within the associated database area, calculate the distance to the nearest base station: When the distance is greater than 2KM, a universal VRS service is provided.

[0131] If the distance is ≤2KM, proceed to the next step of judgment.

[0132] Step 3: Elevation Difference Assessment. Check the elevation difference between the user and the base station, specifically: When the elevation difference is greater than 200m, atmospheric correction single base station service is provided.

[0133] When the elevation difference is ≤200m, single base station service is provided.

[0134] (3) Technical details: a. Topological relationship determination technology, specifically: ① Spatial query: Determine whether a user is within the work area by the spatial relationship between the user's location and the boundary of the work area, and use a spatial database for efficient storage and querying.

[0135] ② Adjacency determination: Determine the adjacency relationship between the user and the base station, and combine the base station coverage and regional characteristics to ensure the selection of an appropriate service mode.

[0136] ③ Range detection: Based on the comparison between user coordinates and the area range, dynamically adjust the adaptation to boundary changes.

[0137] b. Real-time service mode switching, specifically: ①Regional matching optimization: Hierarchical indexing and efficient spatial calculation methods are adopted, and regional attributes and real-time data are combined to optimize matching efficiency.

[0138] ② Data caching strategy: Cache the results of frequently accessed areas and services to reduce redundant calculations and improve response speed.

[0139] ③ Concurrent task support: By introducing asynchronous task queues (such as Kafka or RabbitMQ), it supports the processing of requests from a large number of concurrent users. Kafka is a high-throughput distributed publish-subscribe messaging system; RabbitMQ is an open-source message broker software (also known as message-oriented middleware) that implements the Advanced Message Queuing Protocol (AMQP).

[0140] c. Multi-mode fusion and fault tolerance mechanism, specifically: ① Signal fusion algorithm: Utilize Kalman filtering and particle filtering techniques to optimize positioning results based on multi-source satellite signals.

[0141] ② Calculation of base station distance and elevation difference: The distance between a user and a base station is calculated using the Haversine formula. The Haversine formula is a formula used to calculate the distance between two points of longitude and latitude.

[0142] The elevation difference is calculated based on the height difference between the user and the base station, providing a basis for service type selection.

[0143] ③ Fault tolerance mechanism: The system integrates redundant design, supports multi-source signal switching and automatic identification and recovery of abnormal data, and ensures service continuity and high accuracy.

[0144] (4) Real-time location service engine workflow: Step 1: User Request Processing. The location engine receives the user request and identifies the user's accuracy requirements (based on account type).

[0145] Step 2: Service type determination. Based on the user's location and associated database data, determine whether the user is within the known work area.

[0146] Step 3: Intelligent service switching.

[0147] If the user is within the work area, they can directly select the associated service method.

[0148] If the user is not in the operating area, the optimal service mode is determined by the distance to the base station and the elevation difference.

[0149] Step 4: Generating Correction Data. Based on the selected service mode, generate real-time correction data (such as VRS corrections, PPP-RTK corrections, and atmospheric corrections).

[0150] Step 5: Data Transmission and Feedback. Data is encoded in RTCM message format and transmitted to railway user terminals; service strategies are optimized based on user feedback to ensure efficiency and accuracy. RTCM is a transmission protocol designed to improve the transmission efficiency and positioning accuracy of GNSS data.

[0151] (5) System architecture for implementing real-time location service elasticity: a. Core modules, specifically: ①Accuracy and Service Determination Module: Determines the optimal service mode based on user needs.

[0152] ②Region matching module: Analyzes user location through topology and adjacency relationships to match the optimal service.

[0153] ③ Correction data generation module: generates and encodes location correction data in real time.

[0154] b. Supported modules, specifically: ①CORS Network Management: Manages CORS base stations and data networks.

[0155] ② Atmospheric correction support: Enhance the correction model by combining regional meteorological data.

[0156] (III) Real-time benchmark conversion engine service path (1) Engine components of the real-time benchmark conversion engine service: The real-time benchmark conversion engine consists of a real-time elevation conversion module and a real-time benchmark conversion module. The core technology of the real-time benchmark conversion engine is the seven-parameter encryption technology, and the core technology of the real-time elevation conversion engine is the geoid spatial interpolation and encoding technology.

[0157] (2) The core technologies of the real-time benchmark conversion engine service include seven-parameter encryption technology and geoid spatial interpolation and encoding technology: The seven-parameter encryption technology involves randomly generating a small number of seven-parameter deviations, then calculating pseudo-parameter B based on the original parameter A. The VRS reference station coordinates are then transformed using the Bursa model via pseudo-parameter B and sent to the user. Pseudo-parameter B is also transmitted to the user's receiver via RTCM messages, achieving automatic reference transformation. The technical approach is described in detail below: Step 1: Randomly generate 1000 uniformly distributed points: First, generate 1000 uniformly distributed points. These points represent the original data coordinates that need to be transformed using the seven parameters. They can be latitude, longitude, and altitude in a geographic coordinate system (e.g., WGS-84), or X, Y, and Z coordinates in a projected coordinate system.

[0158] Step 2: Seven-parameter transformation: Use the original seven transformation parameters A (including translation, rotation, and scaling parameters) to perform a seven-parameter transformation on these 1000 points to obtain a new first transformed coordinate set {aa}. This step is the core of the baseline coordinate system transformation.

[0159] Step 3: Randomly generate seven parameters B: Subsequently, a very small set of seven parameters B is randomly generated. These parameters are used to perform a seven-parameter transformation on the same 1000 points to obtain new coordinates bb. Typically, the seven parameters B will have very small perturbation values ​​to simulate small differences between references (such as time differences between references, measurement errors, etc.).

[0160] Step 4: Calculate pseudo-parameter B: For each point, calculate the transformation parameter between the original coordinates aa and the new coordinates bb, i.e., the pseudo-parameter.

[0161] Step 5: By comparing the first transformed coordinate set {aa} with the second transformed coordinate set {bb}, calculate the pseudo-parameter B for each point, and then obtain the pseudo-parameters for the entire dataset.

[0162] Step 6: Reference Station Coordinate Transformation using the Bursa Model: The coordinates of the VRS (Virtual Reference Station) are transformed using the Bursa seven-parameter model. The Bursa model is a widely used standard model for coordinate transformation, suitable for conversion between different coordinate systems. Using pseudo-parameter B, the VRS reference station coordinates are transformed to obtain the new reference station coordinates, which are then transmitted to the rover (user receiver) via a wireless channel.

[0163] Step 7: Send pseudo-parameter B to the user: Pseudo-parameter B is sent to the user receiver in a specific format via an RTCM message (typically using the RTCM 3.x protocol). The M1005 or similar message type in the RTCM message can be used to transmit correction information for these seven parameters. Upon receiving pseudo-parameter B, the user receiver applies these parameters to the coordinate transformation, thereby achieving automatic reference transformation and providing more accurate positioning results.

[0164] The geoid spatial interpolation and coding technique corrects VRS (Virtual Reference Station) observation data by using spatial interpolation of elevation anomalies, and then sends the corrected data to users via RTCM (Real-Time CM) coding technology. This process primarily relies on Kriging interpolation, projection correction, and RTCM message transmission techniques, described in detail below: Step 1: Geoid Data Analysis and Spatial Interpolation: Read the geoid file and extract elevation anomalies. Generate a spatial distribution map of elevation anomalies near the user's location using Kriging interpolation to obtain an accurate estimate of the elevation anomalies.

[0165] Step 2: Kriging Interpolation and Elevation Correction: Use the Kriging interpolation method to calculate the elevation anomaly of the user's location and adjust it to the elevation direction of the VRS coordinate system to ensure that the VRS reference elevation is correctly corrected.

[0166] Step 3: Calculate the projection of the geoid: Based on the VRS station location and satellite location, calculate the projection values ​​of the geoid in each satellite direction. This step maps the elevation error to pseudorange and phase observations using trigonometric and geometric models.

[0167] Step 4: Correct pseudorange and phase observations: Correct the pseudorange and phase observation data received by VRS by subtracting the projected elevation anomalies, thereby eliminating errors caused by elevation differences.

[0168] Step 5: RTCM Message Encoding and Data Transmission: The corrected VRS data is encoded using the RTCM message format and transmitted to the user via a wireless link. The RTCM message format ensures that the data can be accurately parsed by the receiver, thereby achieving high-precision differential positioning.

[0169] (3) Service mode of real-time benchmark conversion engine service: By providing elastic services through source nodes, multiple coordinate systems and elevation benchmarks are offered to users, allowing them to select the appropriate source based on their positioning needs, thus enabling elastic real-time benchmark services.

[0170] (iv) Post-event data processing engine service path (1) Engine components of the post-processing data engine: It consists of modules for datum transformation, baseline calculation, precise single-point positioning, and network adjustment. Its core technologies are seven-parameter transformation, projection transformation, PPP, PPK, and network adjustment.

[0171] (2) Core technologies of the post-event data processing engine: ① Seven-parameter conversion method Different origins of the two coordinate systems will produce translation parameters; non-parallel coordinate axes will produce rotation parameters; inconsistent scales of the two coordinate systems will produce scale parameters. The changes can be calculated using the Bursa seven-parameter model.

[0172] ② Projection transformation method In large-scale map projection, the Gauss-Kruger projection and its derivatives are widely used because their zonal characteristics allow for controllable length distortion. Research on the application of the Gauss projection focuses on three main areas: first, exploration of the correspondence or numerical methods for determining the length ratio of the central meridian, including the universal transverse Mercator projection, the double standard meridian conformal transverse cylindrical projection, and the Gauss-Kruger projection family; second, research on the complex variable function representation of the Gauss projection in Gauss projection transformations, and the forward and inverse formulas for constant and variable coefficients in the Gauss-Kruger projection; and third, research on the spatial Gauss-Kruger projection for satellite imagery.

[0173] As can be seen from the distortion characteristics of the Gauss-Kruger projection, besides angular distortion, it exhibits length and area distortion. Furthermore, the length distortion increases with a longitude difference of 1°; that is, at the equator, a 1° longitude difference results in a length distortion of 0.00015, while a 2° longitude difference results in approximately 0.00015 × 4 = 0.0006. Therefore, to ensure map accuracy, especially for modern large-scale engineering maps, it is necessary to limit the length distortion within a certain range, which is achieved by using a zone projection method. This involves restricting the east-west direction of the projection area to keep its distortion within technical requirements, while areas outside the zone are projected separately using the same projection method. Combining multiple zones allows for the projection of the entire region. Currently, many topographic maps use zone projection methods with longitude differences of 6° and 3° respectively.

[0174] The post-processing data engine's projection transformation function can project vector and raster geographic information elements. It currently supports common methods such as Gauss-Kruger projection, UTM projection, equal area projection, and equal length projection. It can obtain the location information under the target reference and perform visualization operations, making it convenient for users to directly read the correct area and length from the interface.

[0175] ③ Precision single-point positioning method Precise Point Positioning (PPP) employs a non-difference model, based on precise satellite orbits and clock errors provided by the International GNSS Service (IGS). By comprehensively considering various error sources, it achieves high-precision absolute positioning globally using only pseudorange and carrier phase observations from a single receiver. The post-processing engine integrates PPP processing technology based on a dual-frequency, ionospherically-free combination strategy, enabling the acquisition of static centimeter-level and dynamic decimeter-level positioning accuracy using only a single base station in emergency situations.

[0176] For the tropospheric delay along the propagation path, both the wet and dry components can be expressed as the product of the zenith tropospheric delay and the corresponding projection function. The dry component of the tropospheric delay is usually corrected using a priori models, such as the Saastamonin model. However, the wet component of the tropospheric delay has strong uncertainties and is difficult to model precisely; therefore, it is usually obtained through estimation. Other errors, such as phase center offset (PCO) and phase center variation (PCV) at the satellite and receiver ends, relativistic effects, solid tides and ocean tides, and phase entanglement, are all corrected using existing error models. The ionosphere-free composite model uses dual-frequency (multi-frequency) observations to construct ionosphere-free (IF) observations, eliminating the influence of the first-order ionospheric delay. Since the phase observations are generally corrected for satellite clock errors using precision clock products and share the same receiver clock error parameter with the pseudorange observations during the PPP solution process, the pseudorange hardware delay will be introduced into the phase observation equation. This pseudorange hardware delay will be absorbed by the ambiguity parameter to be estimated along with the phase delay. In a dual-frequency ionospheric composite PPP, if observations at the same frequency as the precision satellite clock bias product are used, the satellite-end hardware delay in the pseudorange ionospheric composite can be completely eliminated by the clock bias product; if observations at a different frequency than the clock bias product are used, further pseudorange hardware delay correction is required.

[0177] The stochastic model of observations includes the prior accuracy of each pseudorange and phase observation, and the weighting method of the observations. It is assumed that the prior accuracy of pseudorange or phase observations from different systems and at different frequencies is equal. When using an ionospherically unaffected combination, the accuracy of the combined observations needs to be calculated based on the error propagation law. Observation weighting methods include elevation angle weighting and carrier-to-noise ratio weighting. Among these, elevation angle weighting is the most commonly used.

[0178] The stochastic models of parameters mainly include: (piecewise) constant models, (piecewise) linear models, white noise models, random walk models, and Gauss-Markov models. Among them, white noise models and random walk models can be regarded as special cases of first-order Gauss-Markov models.

[0179] In ionospheric composite PPP, the parameters to be estimated include the station's three-dimensional coordinates, receiver clock bias, tropospheric delay, and phase ambiguity. In non-differential non-composite PPP, the parameters to be estimated also include ionospheric delay. The station coordinate parameters are estimated as constants in static mode and can be considered as epoch-by-epoch estimates of random walks or white noise processes in dynamic mode. Tropospheric delay parameters can be estimated as piecewise constants, piecewise linear processes, or random walk processes, while simultaneously estimating tropospheric gradient parameters. Receiver clock bias parameters are typically estimated as white noise epoch-by-epoch estimates. Ambiguity parameters are estimated as constants in arcs without cycle slips; if cycle slips occur, new ambiguity parameters need to be added. Ionospheric delay can generally also be considered as a random walk process. Various bias parameters require specific analysis of their variation characteristics, and the selection of appropriate stochastic models, commonly constant models and random walk models, are necessary.

[0180] ④ Post-processing dynamic difference method Post-processing kinetic (PPK) is a commonly used method for obtaining dynamic high-precision positioning results. Similar to RTK, it requires acquiring observations from a reference station and a base station, then using single-difference and double-difference observations to eliminate error terms and fix ambiguities, achieving high-precision positioning. Unlike RTK, PPK does not require real-time transmission of base station observations; it only needs observation data files from the base station and rover. Furthermore, to improve positioning accuracy, precise ephemeris, precise clock bias products, and hardware delay products can be introduced to further eliminate error terms that cannot be eliminated during RTK. In dynamic processing, forward and backward filtering methods can be used to smooth the results, resulting in higher theoretical accuracy.

[0181] The post-processing engine integrates a PPK dynamic data post-processing module. It first uses two independent threads to perform forward or backward Kalman filtering. After filtering, RTS smoothing is performed separately. Finally, FBC combination technology is used to fuse the forward or backward smoothing results to obtain high-precision results.

[0182] ⑤ Network adjustment method To achieve flexible positioning services, accurate estimation of observation errors is necessary. The post-processing engine supports robust estimation methods for network adjustment, using M-estimation for observation quality control to combat gross errors. For GNSS systems applying parametric adjustment models, robust solutions can also be derived using the principles of M-estimation. The robustness and effectiveness of robust M-estimation depend primarily on the P-function or Ψ-function used to obtain the equivalent weight function; currently, the most commonly used equivalent weight function is the IGGIII weight function. Generally, when observation outliers are large, the IGGIII equivalent weight function reduces the weight of that observation to 0, which may lead to singular values ​​in the matrix during subsequent calculations. Therefore, when implementing the IGGIII equivalent weight function, the weight of the elimination segment is increased from 0 to the minimum precision of double-precision values.

[0183] (3) Service methods The website provides flexible services, including coordinate datum transformation, projection transformation, elevation transformation, precise single-point positioning, baseline calculation, and network adjustment. Users can choose the appropriate service based on their data processing needs, enabling flexible post-processing of data.

[0184] (v) Environmental Adaptive Services The environment adaptive service module studies the accuracy and efficiency of high-precision services under different work sites and environments, and conducts experimental analysis on satellite-based location service technology, ground-based location service technology, satellite-ground fusion location service technology, and various high-precision location service combination technologies. Based on the work site environment and scenario, the optimal combination service technology is selected, an environment-technology association library is constructed, environment matching is performed according to the user's work location, and the optimal service technology is selected for data service based on the environment, thus realizing environment adaptive service. The input and output information of the environment adaptive service module are shown in Tables 1 and 2.

[0185] Table 1 Input Information Table for Environment Adaptive Service Module Table 2 Output Information of Environment Adaptive Service Module The technical approach for implementing environment adaptive services is as follows: (1) Establish an environment and technology association database First, high-precision location services were launched, providing single-base station, multi-base station, grid VRS, real-time PPP, and PPP-RTK data services along typical railway lines. Different environments and scenarios were selected at different work sites, including high mountains, canyons, rivers, tunnel entrances, and bridges, for testing. The positioning accuracy and efficiency of each service under different scenarios were recorded. The optimal service method was statistically analyzed based on the scenarios, and the test point information and service strategies were recorded to build an environment and technology association library.

[0186] (2) Set up adaptive service access point To improve service reliability, the system will open access points for single base station, multi base station, grid VRS, real-time PPP, and PPP-RTK data services. At the same time, an environment adaptive service access point will be set up. When a user selects this node for work, the adaptive service module will perform geocoding parsing based on the user's location to obtain the user's location environment, and query the service technology from the environment and technology association database. Based on the service technology, the data service software will be scheduled to obtain the correction data.

[0187] (3) Correct the data collection coding The correction data collection and encoding is based on the RTCM protocol, a differential protocol that defines 64 message types, each with a frame length of (N+2) words. The first two words of the message are called the general message. The message information is contained in N words, where N varies depending on the message type, and even messages of the same type may differ due to variations in the number of satellites. RTCM messages consist of a binary data stream, with each word consisting of 30 bits, decomposed into five 6-bit bytes, allowing serial transmission between standard computer universal asynchronous transceivers (UARTs). If the UART provides 8-bit bytes, the two most significant bits must be removed immediately after reading from the communication buffer. Bits 25-30 constitute byte 5, which is a parity check code used to verify the received message information. The RTCM message received by the user is a binary data stream in RTCM format. To obtain the original information from the base station, the user must decode the received data stream.

[0188] This application also provides an electronic device, which may include a processor, a memory, a receiver, and a transmitter. The processor is used to execute the railway user terminal adaptive positioning method mentioned in the above embodiments. The processor and the memory can be connected via a bus or other means, taking a bus connection as an example. The receiver can be connected to the processor and the memory via wired or wireless means.

[0189] The processor can be a central processing unit (CPU). The processor can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips.

[0190] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the railway user terminal adaptive positioning method in the embodiments of this application. The processor executes various functional applications and data processing by running the non-transitory software programs, instructions, and modules stored in the memory, thereby implementing the railway user terminal adaptive positioning method in the above method embodiments.

[0191] The memory may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the processor, etc. Furthermore, the memory may include high-speed random access memory and non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0192] The one or more modules are stored in the memory, and when executed by the processor, the railway user terminal adaptive positioning method in the embodiment is executed.

[0193] In some embodiments of this application, the user equipment may include a processor, a memory, and a transceiver unit. The transceiver unit may include a receiver and a transmitter. The processor, memory, receiver, and transmitter may be connected via a bus system. The memory is used to store computer instructions, and the processor is used to execute the computer instructions stored in the memory to control the transceiver unit to send and receive signals.

[0194] As one implementation method, the functions of the receiver and transmitter in this application can be implemented by transceiver circuits or dedicated transceiver chips, and the processor can be implemented by dedicated processing chips, processing circuits or general-purpose chips.

[0195] As another implementation approach, the server provided in this application embodiment can be implemented using a general-purpose computer. That is, the program code implementing the processor, receiver, and transmitter functions is stored in memory, and the general-purpose processor implements the processor, receiver, and transmitter functions by executing the code in memory.

[0196] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the aforementioned railway user terminal adaptive positioning method. The computer-readable storage medium can be a tangible storage medium, such as random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, floppy disks, hard disks, removable storage disks, CD-ROMs, or any other form of storage medium known in the art.

[0197] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the aforementioned railway user terminal adaptive positioning method.

[0198] Those skilled in the art will understand that the exemplary components, systems, and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software, or a combination of both. Whether implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application. When implemented in hardware, it can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. The programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave.

[0199] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0200] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to the embodiments of this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An adaptive positioning method for railway user terminals, characterized in that, include: If it is determined that the current access method of the target railway user terminal to the railway Beidou application service platform is terminal account login access, then according to the positioning accuracy requirement type corresponding to the target railway user terminal, a real-time positioning service based on the target positioning method corresponding to the positioning accuracy requirement type is provided to the target railway user terminal to send the corresponding real-time positioning data to the target railway user terminal. The target positioning method includes: precise single-point positioning and real-time dynamic positioning method or real-time dynamic differential positioning method. Based on the reference conversion requirement type corresponding to the target railway user terminal, a corresponding real-time reference conversion service is provided to the target railway user terminal to send the corresponding real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can correct the real-time positioning data according to the real-time reference conversion data.

2. The adaptive positioning method for railway user terminals according to claim 1, characterized in that, Also includes: If it is determined that the target railway user terminal is currently accessing the railway Beidou application service platform via web page access, then a post-data processing service based on a post-data processing method is provided to the target railway user terminal to send corresponding post-location service data to the target railway user terminal. The post-data processing method includes at least one of the following: seven-parameter conversion method, projection transformation method, precise single-point positioning method, post-processing dynamic differential method, and network adjustment method.

3. The adaptive positioning method for railway user terminals according to claim 1, characterized in that, Also includes: If the railway Beidou application service platform receives an environment adaptive service instruction from a railway user terminal, it obtains the current environment scene type of the railway user terminal and searches for a positioning service strategy corresponding to the current environment scene type of the railway user terminal from a preset environment and technology association library. It then provides the target railway user terminal with an environment adaptive positioning service based on the positioning service strategy and sends the corresponding environment adaptive positioning service data to the target railway user terminal. The positioning service strategy includes at least one of the following: single base station positioning method, multi base station positioning method, virtual reference station positioning method, precise single point positioning method, and precise single point positioning and real-time dynamic positioning method.

4. The adaptive positioning method for railway user terminals according to claim 1, characterized in that, The step of providing real-time positioning services based on the target positioning method corresponding to the positioning accuracy requirement type of the target railway user terminal, and sending corresponding real-time positioning data to the target railway user terminal, includes: If the positioning accuracy requirement type corresponding to the target railway user terminal is decimeter-level accuracy, then the real-time positioning data corresponding to the target railway user terminal is obtained by the precise single-point positioning and real-time dynamic positioning method, and the real-time positioning data is sent to the target railway user terminal.

5. The adaptive positioning method for railway user terminals according to claim 1, characterized in that, The step of providing real-time positioning services based on the target positioning method corresponding to the positioning accuracy requirement type of the target railway user terminal, and sending corresponding real-time positioning data to the target railway user terminal, includes: If the positioning accuracy requirement type corresponding to the target railway user terminal is centimeter-level accuracy, then determine whether the current user coordinates of the target railway user terminal are located within the geographical range of any preset service area. If the user coordinates of the target railway user terminal are currently within the range of any preset service area, then the real-time dynamic differential positioning method corresponding to that service area is searched from the preset area and service association database. Based on the real-time dynamic differential positioning method, the real-time positioning data corresponding to the target railway user terminal is obtained and sent to the target railway user terminal. The area and service association database stores the correspondence between the geographical range of each service area and its corresponding real-time dynamic differential positioning method. The real-time dynamic differential positioning method includes: virtual reference station positioning method, single base station positioning method, or atmospheric enhancement single base station positioning method. If the user coordinates corresponding to the target railway user terminal are not within the range of any preset service area, then it is determined whether the distance between the target railway user terminal and the nearest base station is less than a distance threshold. If the distance between the target railway user terminal and the nearest base station is equal to or greater than the distance threshold, then the real-time positioning data corresponding to the target railway user terminal is obtained based on the virtual reference station positioning method and the real-time positioning data is sent to the target railway user terminal. If the distance between the target railway user terminal and the nearest base station is less than the distance threshold, then it is determined whether the elevation difference between the target railway user terminal and the nearest base station is less than the elevation difference threshold. If the distance between the target railway user terminal and the nearest base station is less than the elevation difference threshold, then based on the single base station positioning method, the real-time positioning data corresponding to the target railway user terminal is obtained from the nearest base station and the real-time positioning data is sent to the target railway user terminal. If the distance between the target railway user terminal and the nearest base station is equal to or greater than the elevation difference threshold, then based on the atmospheric enhancement single base station positioning method, the real-time positioning data corresponding to the target railway user terminal is obtained from the nearest base station and the real-time positioning data is sent to the target railway user terminal.

6. The adaptive positioning method for railway user terminals according to claim 1, characterized in that, The step of providing corresponding real-time reference conversion services to the target railway user terminal based on the reference conversion requirement type of the target railway user terminal, and sending corresponding real-time reference conversion data to the target railway user terminal, includes: If the benchmark conversion requirement type corresponding to the target railway user terminal includes elevation update requirement, then an elevation anomaly distribution map corresponding to the area range corresponding to the current location of the target railway user terminal is generated based on Kriging interpolation to obtain the elevation anomaly value of the current location of the target railway user terminal. Adjust the elevation anomalies to the elevation direction of the coordinate system where the virtual reference station is located; Obtain the projection values ​​of the elevation anomalies onto each pre-acquired satellite direction; The current observation data of the virtual reference station is corrected based on the projection value to obtain the corrected observation data; The corrected observation data is encoded to obtain encoded data; The encoded data is broadcast as real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can parse the corrected observation data from the encoded data and update the elevation data corresponding to the real-time positioning data based on the corrected observation data.

7. The adaptive positioning method for railway user terminals according to claim 1, characterized in that, The step of providing corresponding real-time reference conversion services to the target railway user terminal based on the reference conversion requirement type of the target railway user terminal, and sending corresponding real-time reference conversion data to the target railway user terminal, includes: If the reference transformation requirement type corresponding to the target railway user terminal includes virtual reference station coordinate transformation requirement, then multiple uniformly distributed coordinate points are constructed to represent the coordinate points to be transformed by seven parameters in the target coordinate system, wherein the target coordinate system includes a geographic coordinate system or a projected coordinate system. The original seven-parameter set is used to perform Bursa model transformation on each of the coordinate points to obtain the first transformed coordinate set; A new set of seven parameters is randomly generated, and a second Bursa model transformation is performed on each coordinate point in the first transformed coordinate set based on the new set of seven parameters to obtain a second transformed coordinate set. The residual matrices corresponding to the first and second transformed coordinate sets are fitted by the least squares method to obtain the pseudo-parameters corresponding to each coordinate point. The pseudo-parameters are injected into the Bursa model to perform encrypted transformation on the current coordinates of the virtual reference station; The coordinates of the virtual reference station after the encryption conversion and the pseudo-parameters are encapsulated and encrypted to obtain the corresponding encrypted data; The encrypted data is broadcast as real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can parse the pseudo-parameter from the encrypted data and perform coordinate conversion on the virtual reference station corresponding to the real-time positioning data based on the pseudo-parameter.

8. The adaptive positioning method for railway user terminals according to claim 2, characterized in that, The provision of post-event data processing services based on post-event data processing methods to the target railway user terminal to send corresponding post-event location service data to the target railway user terminal includes: If the post-event data processing method currently specified by the target railway user terminal includes the seven-parameter conversion method, then the seven-parameter conversion unit in the railway Beidou application service platform is invoked to generate seven-parameter conversion result data for the target railway user terminal, and the seven-parameter conversion result data is sent to the target railway user terminal as post-event positioning service data. If the post-processing method currently specified by the target railway user terminal includes projection transformation, then the projection transformation unit in the railway Beidou application service platform is invoked to generate projection transformation result data for the target railway user terminal, and the projection transformation result data is sent to the target railway user terminal as post-positioning service data. If the post-processing method currently specified by the target railway user terminal includes precise point positioning, then the precise point positioning unit in the railway Beidou application service platform is invoked to generate precise point positioning result data for the target railway user terminal, and the precise point positioning result data is sent to the target railway user terminal as post-processing positioning service data. If the post-processing data processing method currently specified by the target railway user terminal includes the post-processing dynamic differential method, then the post-processing dynamic differential unit in the railway Beidou application service platform is invoked to generate post-processing dynamic differential result data for the target railway user terminal, and the post-processing dynamic differential result data is sent to the target railway user terminal as post-location service data. If the post-processing method currently specified by the target railway user terminal includes network adjustment, then the network adjustment unit in the railway Beidou application service platform is invoked to generate network adjustment result data for the target railway user terminal, and the network adjustment result data is sent to the target railway user terminal as post-location service data.

9. A railway user terminal adaptive positioning system, characterized in that, This includes the real-time service module set up in the railway Beidou application service platform; The real-time service module includes: A real-time positioning service engine is used to provide real-time positioning services based on the target positioning method corresponding to the positioning accuracy requirement type of the target railway user terminal, and send corresponding real-time positioning data to the target railway user terminal if it is determined that the target railway user terminal is currently accessing the railway Beidou application service platform through terminal account login. The target positioning method includes: precise single-point positioning and real-time dynamic positioning method or real-time dynamic differential positioning method. The real-time reference conversion service engine is used to provide the target railway user terminal with the corresponding real-time reference conversion service according to the reference conversion requirement type of the target railway user terminal, and send the corresponding real-time reference conversion data to the target railway user terminal, so that the target railway user terminal can correct the real-time positioning data according to the real-time reference conversion data.

10. The railway user terminal adaptive positioning system according to claim 9, characterized in that, It also includes post-event service modules and environment adaptive service modules, both of which are set in the railway Beidou application service platform; The post-event service module includes: The post-event data processing service engine is used to provide post-event data processing services based on the post-event data processing method to the target railway user terminal if it is determined that the current access method of the target railway user terminal to the railway Beidou application service platform is web page access. The post-event data processing method includes at least one of the following: seven-parameter conversion method, projection transformation method, precise single-point positioning method, post-processing dynamic differential method, and network adjustment method. The environment adaptive service module is used to obtain the current environment scene type of the railway user terminal if it receives an environment adaptive service instruction from the railway user terminal in the railway Beidou application service platform, and search for the positioning service strategy corresponding to the current environment scene type of the railway user terminal from the preset environment and technology association library, and provide the target railway user terminal with environment adaptive positioning service based on the positioning service strategy to send the corresponding environment adaptive positioning service data to the target railway user terminal. The positioning service strategy includes at least one of the following: single base station positioning method, multi base station positioning method, virtual reference station positioning method, precise single point positioning method, and precise single point positioning and real-time dynamic positioning method.

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