Method and device for satellite positioning of terminal equipment

Abstract

The invention provides a method for satellite positioning of a terminal device. The method comprises the following steps: receiving a correction broadcasted by a data processing center and used for improving satellite positioning accuracy by means of a communication unit of the terminal device; distinguishing categories of the received corrections by means of a predefined distinguishing process, the categories of the corrections comprising observation domain corrections and / or state domain corrections; and selecting a positioning algorithm matched with the category of the received correction number based on the distinguishing result, and resolving the accurate position of the terminal equipment by means of the selected positioning algorithm. The invention also provides a device for performing satellite positioning on the terminal equipment, the terminal equipment and a machine readable storage medium.

Description

Technical Field

[0001] The present invention relates to a method for performing satellite positioning on a terminal device. The present invention also relates to an apparatus for performing satellite positioning on a terminal device, a terminal device and a machine-readable storage medium. Background Art

[0002] The Global Navigation Satellite System (GNSS) is a well-known satellite positioning system that uses satellite signals to determine the geographical coordinates of the receiver. However, directly observed satellite signals are affected by a variety of error sources, and relying solely on single-point positioning cannot meet the needs of some fields that require high positioning accuracy and integrity, such as vehicle autonomous driving, flight navigation and landing, etc.

[0003] In order to make up for the above shortcomings, it is proposed to use the GNSS augmentation system to provide real-time correction services to improve the performance and accuracy of terminal positioning. In general, the GNSS augmentation system is mainly based on two types of correction number systems, namely, the observation space representation (OSR) correction number system and the state space representation (SSR) correction number system.

[0004] Most of the current mainstream positioning systems can only support one of the correction number systems and carry a corresponding positioning algorithm. For example, the observation domain correction number system corresponds to the real-time dynamic difference algorithm, and the state domain correction number system corresponds to the precise single point positioning algorithm. Studies have found that these positioning algorithms have their own advantages and disadvantages. In addition, due to the limitation of the correction number broadcast area, if a specific terminal data processing technology is relied on alone in actual applications, high-precision positioning of terminal devices cannot be achieved anytime and anywhere.

[0005] In addition, the prior art also proposes to automatically switch the positioning algorithm according to the network coverage of the terminal device, but this solution lacks active identification of the correction number category. Therefore, in many cases, there is still a positioning algorithm mismatch problem caused by the ambiguity of the correction number category.

[0006] In this context, it is desired to provide a satellite positioning method that is compatible with a variety of correction number systems and can adaptively switch positioning algorithms, so as to more comprehensively improve the positioning accuracy of terminal devices. Summary of the invention

[0007] The object of the present invention is to provide a method for performing satellite positioning on a terminal device, the method comprising the following steps:

[0008] Receiving correction data for improving satellite positioning accuracy broadcasted by a data processing center by means of a communication unit of the terminal device;

[0009] Recognize the categories of the received correction numbers by means of a predefined resolution process, wherein the categories of the correction numbers include observation domain correction numbers and / or state domain correction numbers; and

[0010] Based on the results of the resolution, a positioning algorithm that is suitable for the type of the received correction number is selected, and the precise position of the terminal device is calculated with the help of the selected positioning algorithm.

[0011] The present invention particularly includes the following technical concepts: through a predefined resolution process, the recognition logic of the correction number system is agreed upon, and even in a scenario where multiple correction numbers are broadcast overlappingly or when frequently crossing different correction number broadcasting areas, the received correction number categories can be actively and reliably distinguished, thereby regulating the subsequent satellite positioning process in a targeted manner. Thus, a unified positioning solution compatible with multiple correction number systems is provided. In addition, this standardized correction number resolution process can be flexibly adapted to different terminal devices without the need to independently develop a communication architecture for each terminal device, giving full play to the advantages of different positioning algorithms, so that high-precision satellite positioning is no longer restricted by geographical location and is more convenient to use.

[0012] Optionally, distinguishing the category of the received correction number by means of a predefined distinguishing process includes: determining the category of the correction number by analyzing an identification code used to characterize the category of the correction number, wherein the identification code is included in a reserved flag bit of a data message used to transmit the correction number as part of the data message.

[0013] Therefore, by assigning corresponding identification codes to different correction number categories and agreeing on the storage location and format of the identification codes, the correction number resolution process is unified and standardized, simplifying the operating procedures.

[0014] Optionally, distinguishing the category of the received correction number by means of a predefined distinguishing process comprises: determining the category of the correction number by sending a request about the category of the received correction number to a data processing center and receiving a response to the request from the data processing center.

[0015] Therefore, with the help of this additional communication process, the correction number category can be judged more accurately, laying a solid foundation for supporting diverse correction number systems in terminal equipment.

[0016] Optionally, the correction data broadcasted by the data processing center are received by means of a communication unit of the terminal via a wireless communication network and / or a communication satellite.

[0017] As a result, a variety of correction number release mechanisms and playback methods are covered, making the categories of correction numbers received richer.

[0018] Optionally, the category of the received correction numbers is distinguished by means of a predefined distinguishing process only when the following conditions are met: the correction numbers are received not only via the wireless communication network but also via the communication satellite; and / or the correction numbers are received only via the wireless communication network.

[0019] Therefore, the differences in the correction number broadcasting methods can be used to filter out scenarios where there is ambiguity in the correction number category. In such scenarios, it is necessary to use a predefined resolution process to identify the correction number category, thereby effectively avoiding the failure of the positioning algorithm due to incorrect correction number identification.

[0020] Optionally, when correction numbers are received only through communication satellites and no correction numbers are received through wireless communication networks, the categories of the received correction numbers are not distinguished by means of a predefined resolution process, but it is directly determined that the received correction numbers only involve state domain correction numbers.

[0021] Therefore, the difference in the correction number broadcasting method can be used to filter out the scenarios where there is only a single possibility of correction number category. In this scenario, there is no need to use an additional resolution process to identify the correction number category, thereby saving unnecessary computing overhead and optimizing data processing speed.

[0022] Optionally, the method further comprises the following steps: when correction numbers are received not only through the wireless communication network but also through the communication satellite, and when it is determined with the aid of a predefined resolution process that the received correction numbers only involve state domain correction numbers, deciding by evaluating the communication quality whether to select the state domain correction numbers received through the wireless communication network or through the communication satellite as the data basis for the satellite positioning of the terminal device.

[0023] Therefore, the integrity of the correction signals obtained from the two channels can be compared by evaluating the reliability of the communication connection to ensure the final output of the optimal high-precision positioning result.

[0024] Optionally, selecting a positioning algorithm that is adapted to the category of the received correction numbers based on the resolution result includes: when it is determined that the received correction numbers only involve observation domain correction numbers, selecting a first type of positioning algorithm that is adapted to the observation domain correction numbers to determine the precise position of the terminal device; when it is determined that the received correction numbers only involve state domain correction numbers, selecting a second type of positioning algorithm that is adapted to the state domain correction numbers to determine the precise position of the terminal device, and the first type of positioning algorithm is different from the second type of positioning algorithm.

[0025] Therefore, it is possible to adaptively switch to the corresponding positioning algorithm according to the type of correction numbers broadcast in different regions to achieve precise positioning.

[0026] Optionally, selecting a positioning algorithm adapted to the category of the received correction numbers based on the resolution result includes: when it is determined that the received correction numbers involve not only observation domain correction numbers but also state domain correction numbers, only selecting a first category of positioning algorithms adapted to the observation domain correction numbers to determine the precise position of the terminal device.

[0027] Therefore, considering that the positioning algorithm based on the observation domain correction number can achieve higher positioning accuracy, the best positioning result can be ensured through this optimization logic.

[0028] Optionally, the first type of positioning algorithms includes RTK positioning algorithms and / or NRTK positioning algorithms, and the second type of positioning algorithms includes PPP positioning algorithms, PPP-RTK positioning algorithms and / or PPP-AR positioning algorithms.

[0029] As a result, the terminal equipment can support a variety of positioning algorithms to meet the various needs of different users, different communication link qualities, and different correction number broadcasting areas, and has wide applicability.

[0030] Optionally, the method also includes the following steps: collecting satellite observation data with the help of a terminal device, and determining a first approximate position of the terminal device based on the satellite observation data, the accuracy of the first approximate position being lower than the precise position; when it is determined that the received correction number includes an observation domain correction number, reporting the first approximate position to a data processing center with the help of a communication unit of the terminal device, and receiving a directional observation domain correction number generated for the first approximate position from the data processing center; and correcting the first approximate position based on the directional observation domain correction number with the help of a first type of positioning algorithm adapted to the observation domain correction number to obtain the precise position of the terminal device.

[0031] Therefore, under the premise of determining that the terminal device is in the observation domain correction number broadcasting area, the terminal device can be prompted to actively report its own position, so as to obtain more targeted special enhancement information generated based on its own position. Compared with the situation of directly using the received correction number for positioning, this can effectively improve the positioning accuracy of the terminal device.

[0032] Optionally, the method also includes the following steps: collecting satellite observation data with the help of a terminal device, and determining a first approximate position of the terminal device based on the satellite observation data, the accuracy of the first approximate position being lower than the precise position of the terminal device; when it is determined that the received correction number includes an observation domain correction number, preliminarily correcting the first approximate position based on the received observation domain correction number with the help of a first type of positioning algorithm to obtain a second approximate position of the terminal device, the accuracy of the second approximate position being higher than the first approximate position and lower than the precise position; reporting the second approximate position to a data processing center with the help of a communication unit of the terminal device, and receiving a directional observation domain correction number generated for the second approximate position from the data processing center; and correcting the second approximate position based on the directional observation domain correction number with the help of a first type of positioning algorithm adapted to the observation domain correction number to obtain the precise position of the terminal device.

[0033] Therefore, the enhanced information of the nearby observation domain can be fully utilized to solve the approximate position of the terminal device. Since the enhanced information has been taken into account when calculating the approximate position, the accuracy of the approximate position is higher than that of the result of relying solely on single-point positioning. Therefore, it is helpful for the auxiliary data processing center to find a reference station close to the terminal device based on the approximate position and provide more suitable correction numbers.

[0034] Optionally, the method also includes the following steps: collecting satellite observation data with the help of a terminal device, and determining a first approximate position of the terminal device based on the satellite observation data, the accuracy of the first approximate position being lower than the precise position; and, when it is determined that the received correction numbers only involve state domain correction numbers, correcting the first approximate position based on the received state domain correction numbers with the help of a second type of positioning algorithm adapted to the state domain correction numbers to obtain the precise position of the terminal device.

[0035] Therefore, since the precise single-point positioning algorithm does not require high-bandwidth two-way communication between the terminal device and the data processing center, it can directly use the received state domain enhancement information to correct its own position to achieve high-precision positioning.

[0036] According to a second aspect of the present invention, a device for performing satellite positioning on a terminal device is provided, the device being used to execute the method according to the first aspect of the present invention, the device comprising:

[0037] A receiving module configured to receive correction data for improving satellite positioning accuracy broadcasted by a data processing center via a communication unit of a terminal device;

[0038] a distinguishing module configured to distinguish categories of received correction numbers by means of a predefined distinguishing process, wherein the categories of the correction numbers include observation domain correction numbers and / or state domain correction numbers; and

[0039] The positioning module is configured to select a positioning algorithm adapted to the category of the received correction number based on the result of the identification, and calculate the precise position of the terminal device with the help of the selected positioning algorithm.

[0040] According to a third aspect of the present invention, a terminal device is provided, the terminal device comprising:

[0041] a communication unit configured to receive correction numbers broadcasted by a data processing center for improving satellite positioning accuracy; and

[0042] The device according to the second aspect of the present invention.

[0043] According to a fourth aspect of the present invention, there is provided a machine-readable storage medium, on which a computer program is stored, wherein the computer program is used to execute the method according to the first aspect of the present invention when executed on a computer. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present invention can be better understood. The accompanying drawings include:

[0045] Figure 1a and Figure 1b Schematic diagrams respectively show broadcasting observation domain correction numbers and status domain correction numbers to a terminal device according to the present invention;

[0046] Figure 2 A flow chart of a method for performing satellite positioning on a terminal device according to an exemplary embodiment of the present invention is shown;

[0047] Figure 3a A schematic diagram of a data message for transmitting a correction number according to an exemplary embodiment of the present invention is shown;

[0048] Figure 3b A timing diagram showing a data transmission process between a terminal device and a data processing center according to an exemplary embodiment of the present invention;

[0049] Figure 4 A flow chart of a method for performing satellite positioning on a terminal device according to another exemplary embodiment of the present invention is shown;

[0050] Figure 5a A timing diagram showing a process of performing satellite positioning on a terminal device by means of received observation domain correction numbers according to an exemplary embodiment of the present invention is shown;

[0051] Figure 5bA timing diagram showing a process of performing satellite positioning on a terminal device with the aid of received observation domain correction numbers according to another exemplary embodiment of the present invention; and

[0052] Figure 6 A timing diagram of a process of performing satellite positioning on a terminal device by means of received status domain corrections according to an exemplary embodiment of the present invention is shown; DETAILED DESCRIPTION

[0053] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the scope of protection of the present invention.

[0054] It should be understood that, in this document, the expressions "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance, nor should they be understood as implicitly indicating the number of the indicated technical features.

[0055] Figure 1a and Figure 1b Schematic diagrams are respectively shown for broadcasting observation domain correction numbers and status domain correction numbers to the terminal equipment according to the present invention.

[0056] exist Figure 1a , a scenario of broadcasting observation domain correction numbers to the terminal device 2 according to the present invention is shown. In this scenario, the terminal device 2, which is a mobile station, receives GNSS signals for positioning from a satellite cluster composed of multiple GNSS satellites 10 (this is also called satellite observation data of the terminal device 2) by means of a communication unit 22, for example, and determines the position of the terminal device 2 based on the received GNSS signals. During the measurement, the satellite itself, the propagation path, and the receiver will cause a large number of error terms to be included in the actual observation signal. Here, the terminal device 2 can be an on-board computer, an on-board computer, an on-board intelligent device with software computing functions, etc., or the terminal device 2 can also be any other mobile device.

[0057] exist Figure 1aOne or more reference stations 4 can also be seen, which receive GNSS signals from GNSS satellites 10 (this is also called satellite observation data of reference station 4), and provide raw observation data such as pseudo code ranging information and carrier phase measurement information to the data processing center 3. In some embodiments, the reference station 4 is pre-arranged, so it can be arranged to have a good geometric shape and form a network. On the other hand, the position of the reference station 4 is known. Since many error terms involved in satellite signal observation are strongly related to the region, if the reference station 4 and the terminal device 2 that are geographically close to each other are synchronized to receive satellite signals, the satellite observation results of the reference station 4 can provide calculation and correction of the satellite positioning of the terminal device 2.

[0058] The data processing center 3 receives satellite observation results from the reference station 4 and generates observation domain correction numbers in real time based on the results. Then, the data processing center 3 converts the generated correction numbers, observation data and information of the relevant observation stations into data messages that comply with the communication protocol, and broadcasts these data containing correction numbers to the terminal devices 2 nearby with the help of the wireless communication network 7. Here, the wireless communication network 7 includes but is not limited to: cellular communication network, WIFI communication network and group communication network, etc. In addition, the data processing center 3 can also respond to the request of the terminal device 2, select the observation results of the reference station 4 closest to it according to the approximate location provided by the terminal device 2, and forward them to the terminal device 2 in a directionally manner.

[0059] For the terminal device 2, in order to reliably distinguish the category of the correction number being broadcasted near it and effectively use the correction number to achieve high-precision positioning, the terminal device 2 also includes a device 20 for satellite positioning. The device 20 includes, for example, a receiving module 24, a distinguishing module 26 and a positioning module 28, which are connected to each other in terms of communication technology. The receiving module 24 of the device 20 can be connected to the communication unit 22 of the terminal device 2 to receive the correction number broadcasted by the data processing center 3 through the communication unit 22 for improving the accuracy of satellite positioning. In one embodiment, the receiving module 24 only obtains signals from the communication unit 22 periodically. In another embodiment, the receiving module 24 can also control the working state and signal receiving mode of the communication unit 22 so that the communication unit 22 can selectively access the wireless network, or can tune the communication unit 22 to a certain band or working frequency. The distinguishing module 26 of the device 20 can distinguish the category of the received correction number by means of a predefined distinguishing process. The positioning module 28 can select a positioning algorithm that is compatible with the type of the received correction number based on the result of the identification, and use the selected positioning algorithm to solve the precise position of the terminal device. For example, the positioning module 28 can include multiple different types of positioning solvers, each type of positioning solver corresponds to a specific type of correction number. The positioning module 28 can switch between these positioning solvers or control their respective working modes according to the identified correction number type. For example, when Figure 1a When it is determined in the illustrated scenario that the observation domain correction data has been received, the positioning module 28 may place the real-time kinematic differential solver in the operating mode and the precise point positioning solver in the standby mode.

[0060] exist Figure 1b The scenario of broadcasting observation domain correction numbers to the terminal device 2 according to the present invention is correspondingly shown. In this scenario, multiple reference stations 4' use receivers to receive satellite observation data from GNSS satellites 10, and send the satellite observation data to the data processing center 3' through their own network. The data processing center 3' processes the observation data from each reference station 4' into state domain correction numbers. Specifically, in the data processing center 3', an observation error model is established to describe the absolute error terms in the satellite signal, such as orbital error, satellite clock error, ionospheric delay, atmospheric delay, etc., so as to provide corresponding correction data for these error terms respectively.

[0061] In one embodiment, the data processing center 3' sends the generated state domain correction number to the communication satellite 5 via a satellite uplink. Then, the communication satellite 5 broadcasts the real-time state domain correction number via the L band. The communication satellite 5 may be a geosynchronous satellite that covers a certain range on the earth and broadcasts the correction number from the data processing center 30 within the range via the L band. Accordingly, the terminal device 2 may receive signals from one or more communication satellites 5 via the L band, thereby obtaining the state domain correction number generated and broadcasted by the data processing center 3'.

[0062] In another embodiment, instead of the communication satellite 5 and the satellite uplink, the data processing center 3 can also transmit the state domain correction data via a wireless communication network (such as a cellular wireless network) 7.

[0063] At the terminal device 2, the category of the received correction number can also be distinguished with the help of device 20, and the precise correction data for various errors in the received correction number can be used to correct its own satellite observation results, thereby estimating the precise position of the terminal device 2.

[0064] exist Figure 1b In the positioning mode shown, whether through the communication satellite 5 or the wireless communication network 7, for the terminal device 2, the correction data received by it are globally valid, or have only a small regional relevance. Figure 1b The precise positioning mode eliminates the need for local reference stations and high-bandwidth two-way communications. Figure 1a , Figure 1b The reference stations 4' in the network can be arranged more sparsely.

[0065] Figure 2 FIG. 1 is a flow chart of a method for performing satellite positioning on a terminal device according to an exemplary embodiment of the present invention. The method exemplarily includes steps S1-S3, and can be used, for example, to Figure 1a-1b The device 20 shown is implemented in the case.

[0066] In step S1, correction numbers for improving satellite positioning accuracy broadcasted by a data processing center are received by means of a communication unit of the terminal device.

[0067] It is known that the GNSS satellite signals directly measured by the terminal device contain a large number of error terms, many of which are related to the satellite and the atmosphere. Such error terms cannot be corrected by the terminal device's own communication unit (GNSS receiver), so it can only rely on external data. In this context, the data provided by the external party to improve the satellite positioning accuracy is called "correction number".

[0068] The "data processing center" can also be synonymously referred to as the server, which is the provider of GNSS augmentation services and is used to communicate with different types of reference stations to receive satellite observation data from the reference stations, and then continuously perform overall modeling and solving based on the real-time observation data collected by each reference station, thereby forming corresponding correction numbers, and broadcasting them to various types of terminal devices that require positioning, measurement and navigation. Depending on the correction number system and release mechanism based on the data processing center, the data processing center can broadcast correction numbers to terminal devices in a variety of ways. For example, the data processing center can periodically send correction numbers to communication satellites through uplink stations, and then broadcast various correction numbers through communication satellites. For another example, the data processing center can also broadcast correction numbers to terminal devices through existing wireless communication networks.

[0069] As combined Figure 1a and Figure 1b As explained, the communication unit of the terminal device may include, for example, a network interface and a satellite antenna, whereby it can receive correction numbers both via a wireless communication network and via a communication satellite.

[0070] In step S2, the categories of the received correction numbers are distinguished by means of a predefined distinguishing process, wherein the categories of the correction numbers include observation domain correction numbers and / or state domain correction numbers.

[0071] Generally, corrections can be divided into observation domain corrections and state domain corrections, which differ significantly in the type of data they contain and the correction principles.

[0072] In the observation domain correction number system, the main principle is to recognize that the satellite orbit error, satellite clock error, ionospheric delay, tropospheric delay and other errors have similar effects on two observation stations (such as reference station and terminal equipment) that are not far apart. What is broadcasted from the data processing center to the terminal equipment is the reference station satellite observation data containing error information, which is also called indirect correction number. When positioning, the terminal equipment needs to use its own satellite observation data to make a difference with the satellite observation data of the reference station. Through the differential principle, most of the error information contained in this set of observation data is offset, so that the positioning result obtained is the relative position of the terminal equipment relative to the reference station.

[0073] In the state domain correction number system, the principle is to use global or regional reference station observations to perform physical modeling of the state space model, simulate the errors of the entire region, and describe the parameters of the state space at any given time through modeling. In this case, the absolute error correction number is broadcasted from the data processing center to the terminal device. The terminal device can use this correction number to directly eliminate various error terms related to satellites, signal propagation, etc. in its satellite observation data, thereby directly obtaining a globally unified positioning result, which is also called absolute positioning.

[0074] From the above content, it can be seen that there are obvious differences in content and format between the observation domain correction number and the status domain correction number. However, since the correction number has undergone various pre-processing methods such as encoding, packaging, and compression before being broadcast, it is impossible for the terminal device to directly see the corresponding correction number category through the received original data message. Therefore, it is necessary to use a predefined resolution process to distinguish the category of the correction number.

[0075] In one embodiment, the category of the correction number can be determined by analyzing an identification code that characterizes the category of the correction number. Figure 3a It is shown in the figure and described in detail below.

[0076] In another embodiment, the type of correction number can also be determined through an additional communication process between the terminal device and the data processing center. Figure 3b It is shown in the figure and described in detail below.

[0077] In step S3, a positioning algorithm adapted to the type of the received correction number is selected based on the result of the resolution, and the precise position of the terminal device is calculated with the help of the selected positioning algorithm.

[0078] Here, the precise position refers to the position coordinates after the rough single-point positioning result of the terminal device is corrected based on the differential correction number or the absolute correction number. The precise position has higher accuracy than the approximate position determined directly by the terminal device based on satellite observation data.

[0079] In one embodiment, when it is determined that the received correction number only involves the observation domain correction number, a first type of positioning algorithm adapted to the observation domain correction number is selected to determine the precise position of the terminal device. When it is determined that the received correction number only involves the state domain correction number, a second type of positioning algorithm adapted to the state domain correction number is selected to determine the precise position of the terminal device. The first type of positioning algorithm is different from the second type of positioning algorithm. The first type of positioning algorithm includes, for example, an RTK positioning algorithm and / or an NRTK positioning algorithm. The second type of positioning algorithm includes, for example, a PPP positioning algorithm, a PPP-RTK positioning algorithm, and / or a PPP-AR positioning algorithm.

[0080] Exemplarily, corresponding positioning solvers may be provided in the terminal device for different types of correction numbers, and each solver is completely heterogeneous, thereby providing a more comprehensive positioning output.

[0081] For example, the first positioning solver can use indirect correction numbers to perform positioning on the position, carrier phase and pseudo-range observations collected by the terminal device. Specifically, the first positioning solver subtracts the satellite observations of the terminal device itself from the satellite observations of the reference station (virtual or real) containing various error terms, and eliminates the common partial errors between the two through the difference process. The positioning result obtained is the position of the terminal device relative to the reference station, such as the coordinate difference. Then, the absolute coordinates of the reference station are added to the solved coordinate difference to obtain the absolute coordinates of the terminal device.

[0082] For example, the second positioning solver can use the absolute correction number to directly eliminate the various state quantity error terms (such as satellite clock error, satellite orbit error, satellite phase deviation, ionospheric delay, tropospheric delay, etc.) contained in the carrier phase observation value and pseudorange observation value collected by the terminal device, and the absolute coordinates without error are obtained after correction. It is also possible that, depending on the level of the received state space domain correction number, the second positioning solver can flexibly switch between PPP, PPP-AR, and PPP-RTK positioning algorithms to correct the position as accurately as possible while strictly considering various errors.

[0083] In a specific example, when the terminal device is initially in the observation domain correction number broadcasting area, the first positioning solver can be automatically enabled to use the first type of positioning algorithm based on the observation domain correction number broadcast nearby to achieve accurate position solution; when the terminal device moves from the observation domain correction number broadcasting area to the state domain correction number broadcasting area, the second positioning solver can be automatically enabled to use the second type of positioning algorithm based on the state domain correction number broadcast nearby to achieve accurate position solution. In this way, seamless switching of positioning algorithms based on different correction number systems can be achieved.

[0084] Figure 3a A schematic diagram of a data message for transmitting a correction number according to an exemplary embodiment of the present invention is shown.

[0085] exist Figure 3a3 shows the basic frame structure of an exemplary data message 300 for transmitting correction numbers. Each data message is composed of several bits, for example, wherein the highest bits are synchronization headers 301, followed by satellite numbers 302, the lowest bits correspond to check bits 305, and the middle part is a data field 304, the content of which is determined by the specific information type of the correction number. Each data message 300 can be arranged according to a certain arrangement standard to facilitate decoding and use. In addition, it can be seen that although a part of the data positions 301, 302, 304, and 305 have been defined and occupied in advance in the data message 300, some fields are also reserved in certain positions 303 for each device manufacturer or system supplier to define. In this solution, for example, different identification codes can be defined for different correction categories (i.e., observation domain correction numbers and status domain correction numbers), and the identification codes are placed in the reserved flag bit 303. In one embodiment, the data processing center may add an identification code representing a category to the correction number when packaging the correction number into the data message 300 .

[0086] Figure 3b The timing diagram of the data transmission process between the terminal device and the data processing center according to an exemplary embodiment of the present invention is shown. The data transmission process exemplarily occurs at Figure 1a Between the terminal device 2 and the data processing center 3 shown.

[0087] In step 310, the terminal device 2 establishes a connection with the data processing center 3. In the case where the terminal device 2 is in the correction number broadcasting area of ​​the observation domain, the interaction between the terminal device 2 and the data processing center 3 is generally based on the NTRIP protocol. In other cases, it is also possible to consider extending the NTRIP protocol or defining a new two-way interactive protocol, and the specific interactive protocol type is not limited here. Similarly, in the case where the terminal device 2 is in the correction number broadcasting area of ​​the status domain, the terminal device 2 must first establish a TCP protocol connection with the data processing center 3 before it can receive the correction number from the data processing center 3 or send a request for the correction number category to the data processing center 3.

[0088] In step 320, the terminal device 2 receives correction numbers from the data processing center 3 via the wireless communication network. At this time, the terminal device 2 does not know the specific type of the correction numbers received via the wireless communication network, so it needs to use a predefined resolution process to resolve them.

[0089] Next, the correction number category is distinguished by means of an additional communication process. Specifically, in step 330, in response to receiving the correction number, the terminal device 2 continues to send a request about the category of the received correction number to the data processing center 3.

[0090] In one embodiment, the terminal device 2 may send the request to the data processing center 3 via the communication unit. In particular, when the terminal device 2 receives the correction number but cannot distinguish its category, or cannot distinguish the category of the correction number by predefined means such as identification code, the terminal device 2 may generate and send the request.

[0091] In one embodiment, when the terminal device 2 sends a request regarding the category of the correction number, it also sends the number or sequence information of the data message it received containing the correction number, so that the data processing center 3 can identify whether the data message of the category requested to be identified by the terminal device 2 is valid, or whether it is indeed sent by the data processing center 3.

[0092] In step 340, the terminal device 2 receives a response to the request from the data processing center 3, and thereby determines the type of the correction number received.

[0093] In one embodiment, after receiving the request for the correction number category from the terminal device 2, the data processing center 3 can identify whether the data message is valid based on the data message number and sequence information contained in the request, or identify whether the data message is indeed sent by the data center 3. When the data message is determined to be valid, the data processing center 3 can send a corresponding response to the terminal device 2 to indicate the category of the correction number received by the terminal device 2. Otherwise, the data processing center 3 does not send a response to the terminal device 2 in the subsequent steps, or only sends a rejection response.

[0094] In one embodiment, the response generated and sent by the data processing center 3 may include an identification code for characterizing the type of the correction number in a reserved field, so that the terminal device 2 can efficiently determine the type of the correction number it requests by checking the identification code in the response.

[0095] pass Figure 3b Although the additional communication process shown increases the communication traffic to a certain extent, the data processing center 3 does not need to pre-add an identification code for characterizing the category for each correction number to be broadcast, because not all terminal devices 2 are compatible with multiple correction number systems and need to identify the category of the correction number received. For those terminal devices 2 that only support one correction number and are equipped with only one terminal data processing technology, they can directly ensure that only the correction number category supported by them is received through pre-configured communication permissions. Figure 3b The process shown reduces the data processing burden on the data processing center 3 .

[0096] Figure 4 A flow chart of a method for performing satellite positioning on a terminal device according to another exemplary embodiment of the present invention is shown. In this embodiment, Figure 2Step S1 of the method shown includes sub-steps S11 - S12 , step S2 includes sub-step S21 , and step S3 includes sub-steps S31 - S35 .

[0097] exist Figure 4 In the illustrated scenario, before executing step S11, the correction number broadcasted by the data processing center has been received via the communication unit of the terminal device.

[0098] In step S11, the current operating mode of the communication unit is analyzed to determine whether corrections are received not only via the wireless communication network but also via the communication satellite.

[0099] If the above situation is true, combined with the respective broadcasting mechanisms of observation domain correction numbers and status domain correction numbers, it can be inferred that there are the following three possibilities:

[0100] - Observation domain corrections are received via the wireless communication network, and state domain corrections are received via the communication satellite;

[0101] - Observation domain corrections and state domain corrections are received via the wireless communication network, and state domain corrections are received via the communication satellite;

[0102] -State domain corrections are received via the wireless communication network and also via the communication satellite.

[0103] That is, when corrections are received through two channels at the same time, it can only be inferred that the received corrections must contain state domain corrections, but it is impossible to distinguish whether observation domain corrections are also received at the same time. In this case, it is necessary to identify the type of corrections through further inspection measures, so the type of the received corrections can be distinguished in step S21 by means of a predefined distinction process.

[0104] If it is determined in step S11 that the corrections are not received via both the wireless communication network and the communication satellite but are received via only one of the channels, then in step S12 it is checked whether the corrections are received via only the wireless communication network.

[0105] If it is determined in step S12 that the corrections are received only through the wireless communication network, combined with the respective broadcasting mechanisms of the observation domain corrections and the status domain corrections, it can be inferred that there are the following three possibilities:

[0106] - Observation domain corrections are received via the wireless communication network, and state domain corrections are received via the wireless communication network;

[0107] -Only observation domain corrections are received via the wireless communication network;

[0108] -Only status domain corrections are received via the wireless communication network.

[0109] At this point, it can only be confirmed that the terminal device is in the network coverage area, but it is still not possible to uniquely and clearly determine which correction number broadcast area it is in, so it is still impossible to accurately select an adaptive positioning algorithm to perform satellite positioning. In this case, it is also necessary to use a predefined resolution process in step S21 to resolve the category of the received correction number.

[0110] On the contrary, if it is determined in step S12 that no corrections are received through the wireless communication network, it means that the corrections are only received through the communication satellite at this time. In combination with the corresponding correction broadcasting mechanism, it can be known that there is only one possible situation at this time: the corrections received are only state domain corrections. This is because only state domain corrections are transmitted to users via the communication link of the communication satellite. At this time, there is no category ambiguity problem in the received corrections, so there is no need to use a predefined resolution process to resolve the category of the corrections, so step S21 can be skipped and it can be directly determined in step S33 that the received corrections only involve state domain corrections.

[0111] The specific form and operation steps of the resolution process implemented in step S21 have been combined with Figure 3a-Figure 3b The detailed description will not be repeated here. With the help of the predefined discrimination process, three different conclusions about the correction number category can be obtained.

[0112] For example, in step S31, it is determined that the received corrections only involve observation domain corrections, which means that the terminal device is currently in the broadcast area of ​​observation domain corrections. In step S32, it is determined that the received corrections involve not only observation domain corrections but also state domain corrections, which means that the terminal device is currently in the overlapping broadcast area of ​​observation domain corrections and state domain corrections. In step S33, it is determined that the received corrections only involve state domain corrections, which means that the terminal device is currently in the broadcast area of ​​state domain corrections.

[0113] In response to the results of distinguishing the correction number categories in steps S31-S33, an adapted positioning algorithm may be selected in steps S34 and S35.

[0114] Specifically, for the resolution results of step S31 and step S32, that is, for the case where the received corrections only involve the observation domain corrections, and for the case where the received corrections involve not only the observation domain corrections but also the state domain corrections, the first type of positioning algorithm adapted to the observation domain corrections is selected in step S34 to determine the precise position of the terminal device. For the case where two corrections are received at the same time, the reason for abandoning the use of the received state domain corrections is that, compared with the precise single-point positioning technology based on the state domain corrections, the observation domain corrections can be used to quickly solve the precise position of the terminal device by using position differences, without the need for convergence time, and there is no problem of difficulty in fixing ambiguity parameters, so the positioning solution obtained is more reliable.

[0115] For the resolution result in step S33, that is, for the case where the received corrections only involve state domain corrections, a second type of positioning algorithm adapted to the state domain corrections is selected in step S35 to determine the precise position of the terminal device.

[0116] In one embodiment, the resolution result in step S33 can be further subdivided into: receiving state domain corrections only through a wireless communication network or only through a communication satellite; and receiving corrections not only through a wireless communication network but also through a communication satellite. In the former case, since the received corrections are obtained by only one communication channel, the received correction data can be directly used as the data basis to achieve precise positioning. In the latter case, it is also possible to further evaluate the communication quality to decide whether to choose state domain corrections received through a wireless communication network or through a communication satellite as the data basis for satellite positioning of the terminal device. For example, the signal strength, round-trip delay, propagation environment interference and obstruction of the network communication link and the satellite communication link can be checked respectively, so as to calculate the corresponding communication quality. In this way, it can be ensured that reliably transmitted correction signals are used as much as possible for satellite positioning.

[0117] Figure 5a FIG. 1 shows a timing diagram of a process of performing satellite positioning on a terminal device by means of received observation domain corrections according to an exemplary embodiment of the present invention. The data transmission process exemplarily occurs at Figure 1a Between the terminal device 2 and the data processing center 3 shown.

[0118] In step 510, satellite observation data is collected by means of the terminal device 2, and the first approximate position of the terminal device 2 is determined based on the satellite observation data. Specifically, when performing satellite positioning, the ephemeris data and measurement signals sent by the GNSS satellite are first received by the communication unit (GNSS receiver) of the terminal device 2. After receiving these signals, the distance between the GNSS receiver and the GNSS satellite can be calculated in the terminal device according to the time interval between the sending signal and the receiving signal. However, since there is inevitably a clock error between the satellite clock and the receiver clock, and the signal is affected by factors such as atmospheric refraction during propagation, the distance calculated in this way is not equal to the actual distance from the GNSS satellite to the GNSS receiver, but only a rough distance. When the terminal device 2 calculates this rough distance between itself and multiple satellites, its first approximate position on the surface of the earth is determined. It can be understood that this first approximate position is lower in accuracy than the precise position ultimately provided for high-precision positioning, navigation or autonomous driving decision-making.

[0119] In step 520, the correction number broadcasted by the data processing center 3 is received by means of the communication unit of the terminal device 2. In the embodiment shown in FIG5 , the terminal device 2 receives the broadcasted correction number, for example, through a wireless communication network. It can be seen from the publishing mechanism of the observation domain correction number and the state domain correction number that both correction numbers can be transmitted through the wireless communication network. Therefore, for the terminal device 2, it is impossible to directly infer which correction number it has received through the receiving method.

[0120] In step 530, after receiving the corresponding correction number, the terminal device 2 uses a predefined resolution process to identify the category of the correction number it receives. In this embodiment, for example, it is determined that the correction number received is an observation domain correction number. However, at this time, the terminal device 2 cannot directly use the received observation domain correction number for precise positioning, because: the observation domain correction number received in this way is sent by the data processing center 3 to the surrounding user group through the network in a broadcast form, which may include correction numbers of multiple reference stations, or may only include correction numbers of any one reference station. For the terminal device 2, the directly received observation position data or differential data may not be the most ideal, that is, the observation position data or differential data of the reference station or virtual reference station closest to the terminal device 2.

[0121] This shows that although terminal device 2 uses RTK differential observation values ​​for calculation, most satellite signal errors can be eliminated during this period. However, as the distance between terminal device 2 and the reference station increases, this difference in geographical location will cause the error terms to gradually increase. When the distance between terminal device 2 and the corresponding reference station exceeds a certain range, the positioning result will be greatly affected.

[0122] In step 540, the terminal device 2 has identified that it is in the broadcasting area of ​​the observation domain correction number, so it can report its own first approximate position to the data processing center 3 in real time by means of the communication unit, and receive the dedicated enhancement information generated based on the first approximate position from the data processing center 3 in step 550. Specifically, after receiving the first approximate position of the terminal device 2, the data processing center 3 will select the corresponding reference station according to the first approximate position, generate the directional observation domain correction number based on the observation data transmitted in real time by the selected reference station, and then broadcast the directional observation domain correction number to the terminal device 2.

[0123] In step 560, after receiving the dedicated enhancement information customized for its location, the terminal device 2 performs RTK filtering and solving in combination with its own first approximate position, thereby obtaining the precise position of its own measurement point.

[0124] It should be noted that although Figure 5a Although not shown in the figure, the process of establishing a network connection (e.g., establishing an NTRIP data transmission protocol connection) between the terminal device 2 and the data processing center 3 may also be included before step 520. The authentication process of both parties can be implemented in the process of establishing a network connection between the terminal device 2 and the data processing center 3. In one embodiment, there may be multiple terminal devices 2 that simultaneously establish a network connection with the data processing center 3, and the data processing center 3 periodically multicasts the correction number to the multiple terminal devices 2 through the wireless communication network.

[0125] Figure 5b A timing diagram of a process of performing satellite positioning on a terminal device with the help of received observation domain correction numbers according to another exemplary embodiment of the present invention is shown. Figure 5b In the implementation process of steps 510, 520 and 530, Figure 5a The corresponding steps are the same and have the same reference numerals, and will not be repeated here. Figure 5b and Figure 5a The difference.

[0126] like Figure 5bAs shown, after the terminal device 2 uses the predefined resolution process to identify the correction number it receives as the observation domain correction number in step 530, in step 531, the terminal device 2 can select the first type of positioning algorithm adapted to the observation domain correction number, and use the first type of positioning algorithm to preliminarily correct the first approximate position based on the received observation domain correction number to obtain the second approximate position of the terminal device 2. The accuracy of the second approximate position calculated in this way is higher than the first approximate position determined by the terminal device 2 completely by direct observation data. However, since the observation domain correction number currently received is not generated for the actual position of the terminal device 2, the accuracy of the second approximate position still does not meet the requirements of tasks such as high-precision positioning and autonomous driving decision-making, so it is still lower than the accuracy of the final required precise position.

[0127] In one embodiment, if the data processing center 3 broadcasts the observed position data or differential data of multiple reference stations to the terminal device 2. For example, several reference stations can be divided into a subnet, and within the coverage of each subnet, the terminal device 2 can receive the correction information of all reference stations in the entire subnet. Therefore, after receiving these corrections, the terminal device 2 can automatically select the reference station closest to its position according to its own first approximate position, and use the corrections about the reference station to perform differential positioning to obtain the second approximate position.

[0128] In another embodiment, if the data processing center 3 only broadcasts the correction number about a single reference station to the terminal device 2, the terminal device 2 can directly determine the second approximate position based on the received correction number.

[0129] In step 541, the terminal device 2 reports the second approximate position to the data processing center 3, and receives the dedicated enhancement information determined based on the second approximate position from the data processing center 3 in step 551. Here, the dedicated enhancement information refers to the observation domain correction number generated for the orientation by the data processing center 3 according to the second approximate position reported by the terminal device 2, and the orientation observation domain correction numbers obtained by different terminal devices 2 may be different.

[0130] Next, in step 561 , the terminal device 2 may correct the second approximate position based on the directional observation domain correction number received in step 551 by means of a first type of positioning algorithm adapted to the observation domain correction number to obtain the precise position of the terminal device 2 .

[0131] and Figure 5a By comparison with the embodiments shown, it can be seen that Figure 5bIn the embodiment, the data processing center 3 generates correction numbers in a targeted manner according to the second approximate position with higher accuracy and transmits them back to the terminal device 2. In this case, the reference station selected by the data processing center 3 is closer to the actual position of the terminal device 2. Therefore, the error term affecting the positioning accuracy is smaller between the terminal device 2 and the reference station. By eliminating the difference of the observation values ​​between the stations, more accurate satellite positioning can be achieved.

[0132] Figure 6 FIG. 1 shows a timing diagram of a process of performing satellite positioning on a terminal device by means of received state domain corrections according to an exemplary embodiment of the present invention. The data transmission process exemplarily occurs at Figure 1b Between the terminal device 2 and the data processing center 3' shown.

[0133] In step 610, satellite observation data is collected by means of the terminal device 2, and a first approximate position of the terminal device 2 is determined based on the satellite observation data. This step is similar to Figure 5a , Figure 5b Step 510 in is performed in a similar manner and will not be repeated here.

[0134] In step 620 , the data processing center 3 ′ broadcasts the status field correction number to the terminal device 2 .

[0135] In one embodiment, the data processing center 3' can send the state domain correction number to the uplink station on the ground, so as to send it to the communication satellite through the uplink station via the satellite uplink, and then broadcast the correction number through the L band via the communication satellite. Correspondingly, the terminal device 2 can receive the correction number broadcasted by the communication satellite on the L band by means of the communication unit.

[0136] In another embodiment, the data processing center 3' may also send the status domain correction number to the terminal device 2 via the wireless communication network. Figure 6 Although not shown in the figure, before step 620, the process of establishing a network connection (eg, establishing a TCP transmission control protocol connection) between the terminal device 2 and the data processing center 3' may also be included.

[0137] In step 630, after receiving the corresponding correction number, the terminal device 2 uses a predefined identification process to identify the type of the correction number it receives, for example, determining that the received correction number is a state domain correction number.

[0138] Different from Figure 5a and Figure 5b As shown, Figure 6In the illustrated embodiment, the received state domain corrections are absolute error corrections, which can describe the parameters of the state space model at any given time, and are not limited to the location of the terminal device 2. Therefore, there is no need to further report the first approximate location of the terminal device 2 to the data processing center 3', thereby ensuring the security and privacy of user data.

[0139] In step 640, when it is determined that the received corrections only involve state domain corrections, the first approximate position is corrected based on the received state domain corrections by means of a second type of positioning algorithm adapted to the state domain corrections, so as to obtain the precise position of the terminal device 2. Therefore, the terminal device 2 can directly use this absolute error correction to correct satellite orbit error, satellite clock error, tropospheric delay, atmospheric delay and other error items contained in its own observation data.

[0140] It should be noted that for the sake of brevity, Figure 5a , Figure 5b and Figure 6 The wireless communication network, communication satellite and related uplink stations are not shown between the terminal device 2 and the data processing centers 3, 3', but those skilled in the art should be able to understand that in order to realize the data transmission process between the terminal device 2 and the data processing centers 3, 3', it is necessary to use the wireless communication network and / or communication satellite, so there must be a related connection path.

[0141] It can be understood that the methods of various embodiments of the present disclosure can be implemented by computer programs / software. These software can be loaded into the working memory of the processor and used to execute the methods according to various embodiments of the present disclosure when running.

[0142] According to another embodiment of the present disclosure, a machine-readable storage medium is provided, such as a CD-ROM, which includes a computer program, which, when executed, causes a computer or a processor to perform a method according to each embodiment of the present disclosure. The machine-readable storage medium is, for example, an optical storage medium or a solid-state medium supplied together with other hardware or as part of other hardware.

[0143] Although specific embodiments of the present invention are described in detail herein, they are provided for the purpose of explanation only and should not be considered to limit the scope of the present invention. Various substitutions, changes and modifications may be conceived without departing from the spirit and scope of the present invention.

Claims

1. A method for performing satellite positioning on a terminal device (2), the method comprising the following steps: Receiving correction data for improving satellite positioning accuracy broadcasted by a data processing center (3, 3') by means of a communication unit (22) of a terminal device (2); Recognize the categories of the received correction numbers by means of a predefined resolution process, wherein the categories of the correction numbers include observation domain correction numbers and / or state domain correction numbers; and Based on the result of the discrimination, a positioning algorithm adapted to the type of the received correction number is selected, and the precise position of the terminal device (2) is calculated with the aid of the selected positioning algorithm.

2. The method according to claim 1, wherein: The categories of corrections received are resolved using a predefined resolution process: The category of the correction number is determined by analyzing an identification code used to characterize the category of the correction number, wherein the identification code is contained in a reserved flag bit (303) of a data message (300) as a part of the data message (300) used to transmit the correction number.

3. The method according to claim 1 or 2, wherein: The categories of corrections received are resolved using a predefined resolution process: The category of the correction number is determined by sending a request about the category of the received correction number to a data processing center (3, 3') and receiving a response to the request from the data processing center (3, 3').

4. The method according to any one of claims 1 to 3, wherein: The correction data broadcasted by the data processing center (3, 3') is received by means of a communication unit (22) of the terminal device (2) via a wireless communication network (7) and / or a communication satellite (5).

5. The method according to any one of claims 1 to 4, wherein: The received corrections are classified using a predefined classification process only when the following conditions are met: Corrections are received not only via the wireless communication network (7) but also via the communication satellite (5); and / or Corrections are only received via the wireless communication network (7).

6. The method according to claims 1 to 5, wherein: When correction numbers are received only through the communication satellite (5) and no correction numbers are received through the wireless communication network (7), the category of the received correction numbers is not distinguished by means of a predefined distinction process, but it is directly determined that the received correction numbers only involve status domain correction numbers.

7. The method according to any one of claims 1 to 6, wherein: The method further comprises the following steps: When correction numbers are received not only via the wireless communication network (7) but also via the communication satellite (5), and when it is determined by a predefined resolution process that the received correction numbers only relate to state domain correction numbers, a decision is made by evaluating the communication quality to select the state domain correction numbers received via the wireless communication network (7) or via the communication satellite (5) as the data basis for satellite positioning of the terminal device (2).

8. The method according to any one of claims 1 to 7, wherein: The positioning algorithms selected based on the results of the resolution and adapted to the type of correction numbers received include: When it is determined that the received correction numbers only involve observation domain correction numbers, a first type of positioning algorithm adapted to the observation domain correction numbers is selected to determine the precise position of the terminal device (2); when it is determined that the received correction numbers only involve state domain correction numbers, a second type of positioning algorithm adapted to the state domain correction numbers is selected to determine the precise position of the terminal device (2); the first type of positioning algorithm is different from the second type of positioning algorithm.

9. The method according to any one of claims 1 to 8, wherein: The positioning algorithms selected based on the results of the resolution and adapted to the type of correction numbers received include: When it is determined that the received correction numbers involve not only observation domain correction numbers but also state domain correction numbers, only a first type of positioning algorithm adapted to the observation domain correction numbers is selected to determine the precise position of the terminal device (2).

10. The method according to claim 8 or 9, wherein: The first type of positioning algorithms includes RTK positioning algorithms and / or NRTK positioning algorithms, and the second type of positioning algorithms includes PPP positioning algorithms, PPP-RTK positioning algorithms and / or PPP-AR positioning algorithms.

11. The method according to any one of claims 1 to 10, wherein: The method further comprises the following steps: Collecting satellite observation data with the aid of a terminal device (2), and determining a first approximate position of the terminal device (2) based on the satellite observation data, wherein the accuracy of the first approximate position is lower than that of the precise position; When it is determined that the received correction number includes an observation domain correction number, the first approximate position is reported to a data processing center (3, 3') by means of a communication unit (22) of the terminal device (2), and a directional observation domain correction number generated for the first approximate position is received from the data processing center (3, 3'); and The first approximate position is corrected based on the directional observation domain correction number by means of a first type of positioning algorithm adapted to the observation domain correction number, so as to obtain the precise position of the terminal device (2).

12. The method according to any one of claims 1 to 10, wherein: The method further comprises the following steps: Collecting satellite observation data with the aid of a terminal device (2), and determining a first approximate position of the terminal device (2) based on the satellite observation data, wherein the accuracy of the first approximate position is lower than the precise position of the terminal device (2); When it is determined that the received correction number includes the observation domain correction number, preliminarily correcting the first approximate position based on the received observation domain correction number by means of a first type of positioning algorithm to obtain a second approximate position of the terminal device (2), wherein the accuracy of the second approximate position is higher than that of the first approximate position and lower than that of the precise position; Reporting the second approximate position to a data processing center (3, 3') by means of a communication unit (22) of the terminal device (2), and receiving a directional observation domain correction number generated for the second approximate position from the data processing center (3, 3'); and The second approximate position is corrected based on the directional observation domain correction number by means of a first type positioning algorithm adapted to the observation domain correction number, so as to obtain the precise position of the terminal device (2).

13. The method according to any one of claims 1 to 12, wherein: The method further comprises the following steps: Collecting satellite observation data with the aid of a terminal device (2), and determining a first approximate position of the terminal device (2) based on the satellite observation data, wherein the accuracy of the first approximate position is lower than that of the precise position; and When it is determined that the received corrections only involve state domain corrections, the first approximate position is corrected based on the received state domain corrections by means of a second type positioning algorithm adapted to the state domain corrections to obtain the precise position of the terminal device (2).

14. A device (20) for performing satellite positioning on a terminal device (2), the device (20) being used to execute the method according to any one of claims 1 to 13, the device (20) comprising: A receiving module (24) configured to receive correction numbers for improving satellite positioning accuracy broadcasted by a data processing center (3, 3') by means of a communication unit (22) of a terminal device (2); A distinguishing module (26) is configured to distinguish the categories of the received correction numbers by means of a predefined distinguishing process, wherein the categories of the correction numbers include observation domain correction numbers and / or state domain correction numbers; as well as A positioning module (28) is configured to select a positioning algorithm suitable for the type of the received correction number based on the result of the identification, and calculate the precise position of the terminal device (2) with the help of the selected positioning algorithm.

15. A terminal device (2), comprising: A communication unit (22) configured to receive correction data for improving satellite positioning accuracy broadcasted by a data processing center (3, 3'); and The device (20) according to claim 14. 16 . A machine-readable storage medium having a computer program stored thereon, the computer program being configured to execute the method according to claim 1 when executed on a computer.

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