An Ionospheric Adaptive Enhancement Positioning Method and Device

Abstract

This invention provides an ionospheric adaptive enhanced positioning method and apparatus, belonging to the field of positioning technology. It can determine the activity of the ionosphere using ionospheric uncertainty information and select a more suitable positioning method for user equipment based on the determination result, thereby improving the positioning accuracy of the user equipment. The method is based on cross-validation and ionospheric delay correction information from each of the multiple ground monitoring stations to determine the ionospheric uncertainty information of each of the multiple navigation satellites. The ionospheric uncertainty information is used to determine the activity of the ionosphere between the navigation satellite and the ground monitoring station, and the method for positioning the user equipment is selected based on the determination result, thus achieving the positioning of the user equipment.

Description

Technical Field

[0001] This invention relates to the field of positioning technology, and in particular to an ionospheric adaptive enhanced positioning method and apparatus. Background Technology

[0002] A Global Navigation Satellite System (GNSS) is a system that uses satellite signals for global positioning, providing users with high-precision positioning services. Existing methods (e.g., PPP-RTK) often use positioning signals from navigation satellites combined with positioning enhancement information to accurately locate user equipment. This positioning enhancement information includes corrections such as ephemeris error corrections, satellite clock error corrections, and ionospheric delay corrections.

[0003] However, due to the active and irregular nature of the ionosphere, existing fitting models or interpolation models such as grids cannot accurately describe the ionospheric change characteristics during periods of ionospheric activity. Consequently, when performing real-time positioning of user equipment during periods of ionospheric activity, it is difficult to obtain high-precision ionospheric delay corrections, resulting in low positioning accuracy for positioning methods that rely on ionospheric delay corrections. Summary of the Invention

[0004] This invention proposes an ionospheric adaptive enhanced positioning method and apparatus, which can determine whether the ionosphere is active by using ionospheric uncertainty information, and select a more suitable positioning method for user equipment based on the determination result, thereby improving the positioning accuracy of user equipment.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides an ionospheric adaptive augmentation positioning method, which positions user equipment using a Global Navigation Satellite System (GNSS). The GNSS includes a ground-based end and a space-based end. The ground-based end includes multiple ground monitoring stations and a data center, and the space-based end includes multiple navigation satellites. The method includes: the data center determining ionospheric delay information for each of the multiple ground monitoring stations based on an ambiguity fixing method; the ionospheric delay information includes ionospheric tilt delay data between the ground monitoring station and each of the multiple navigation satellites. For each of the multiple ground monitoring stations, the data center determines ionospheric delay correction information for the ground monitoring station based on the ionospheric tilt delay information of the multiple ground monitoring stations and an inverse distance linear interpolation method; the ionospheric delay correction information for the ground monitoring station includes ionospheric delay correction data between the ground monitoring station and each of the multiple navigation satellites. The data center determines ionospheric uncertainty information for each of the multiple navigation satellites based on cross-validation and the ionospheric delay correction information of each of the multiple ground monitoring stations. The data center broadcasts the ionospheric uncertainty information of each of the multiple navigation satellites for the positioning of user equipment. The ionospheric uncertainty information is used to determine whether the ionosphere between the navigation satellite and the ground monitoring station is active, and the method for positioning the user equipment is selected based on the determination result.

[0007] In one implementation of the first aspect, for each of the multiple ground monitoring stations, the data center determines the ionospheric delay correction information of the ground monitoring station based on the ionospheric delay information of the multiple ground monitoring stations and the inverse distance linear interpolation method, including:

[0008] For each of the multiple ground monitoring stations:

[0009] Using ground monitoring stations as central stations, multiple station networks are constructed based on multiple average distances. Each station network includes multiple ground monitoring stations centered on the central station. Each station network corresponds to an average distance, which is the average of the distances between the multiple ground monitoring stations in the station network and the central station.

[0010] The ionospheric delay information of multiple ground monitoring stations in each of the multiple station networks is interpolated using the inverse distance linear interpolation method to obtain the ionospheric delay correction information of the central station; the ionospheric delay correction information of the central station satisfies the following formula.

[0011]

[0012] Where s represents the navigation satellite number, j represents the station network number, and u represents the central station. This represents the ionospheric delay correction data between the central station corresponding to the j-th station network and the navigation satellite numbered s; m represents the number of ground monitoring stations in the j-th station network. This represents the i-th ground monitoring station in the station network. This represents the ionospheric delay information of the i-th ground monitoring station in the network of stations; express The weights, and This represents the distance between the i-th ground monitoring station and the central station in the station network;

[0013] Ionospheric delay correction information is obtained for each of the multiple ground monitoring stations.

[0014] In one implementation of the first aspect, for each of the multiple navigation satellites, the ionospheric uncertainty information of the navigation satellite includes the ionospheric uncertainty information between each of the multiple ground monitoring stations and the navigation satellite; the ionospheric uncertainty information between each of the multiple ground monitoring stations and the navigation satellite satisfies the following formula;

[0015]

[0016] Where 's' represents the navigation satellite number and 'I' represents the ground monitoring station number. The ionospheric uncertainty information between the navigation satellite and the ground monitoring station is represented by a0 and a1, which satisfy the following formula;

[0017]

[0018] Where 's' represents the navigation satellite number; This indicates the ionospheric uncertainty information between the ground monitoring station in the first station network corresponding to the ground monitoring station and the navigation satellite numbered s; This represents the ionospheric uncertainty information between the ground monitoring station and the navigation satellite numbered s in the j-th station network corresponding to the ground monitoring station; p represents the total number of multiple measurement networks in which the ground monitoring station serves as the central station; This represents the ionospheric uncertainty information between the p-th ground monitoring station in the corresponding ground monitoring station network and the navigation satellite numbered s; d1 represents the average distance of the first station network; d j d represents the average distance of the network of stations at the j-th station; p This represents the average distance of the network at the p-th station.

[0019] The following formula must be satisfied;

[0020]

[0021] Where n represents the total number of epochs required to determine the ionospheric delay information of the ground monitoring station; This represents the ionospheric tilt delay data between the ground monitoring station and the navigation satellite numbered s. The difference between the two data can be calculated.

[0022] In one implementation of the first aspect, the method further includes:

[0023] For each of the multiple navigation satellites, the user equipment receives the ionospheric uncertainty information of the navigation satellite from the data center, and determines the correction value of the ionospheric uncertainty information of the navigation satellite based on the elevation angle of the navigation satellite; the correction value satisfies the following formula:

[0024]

[0025] Where 's' represents the navigation satellite number, 'I' represents the ground monitoring station number, and 'ele' represents the elevation angle between the ground monitoring station and the navigation satellite. This represents a correction value for ionospheric uncertainty information between navigation satellites and ground monitoring stations;

[0026] User equipment uses the correction values ​​of ionospheric uncertainty information of each of multiple navigation satellites and the ionospheric delay information of each of multiple ground monitoring stations to determine whether the ambiguity fixing method is ambiguity fixed.

[0027] When the ambiguity is fixed by the determination method, the user equipment uses a non-difference, non-combination model for positioning.

[0028] When the ambiguity determination method is not fixed, the user equipment determines whether the ionosphere is active by using the correction value of the ionospheric uncertainty information of each of the multiple navigation satellites. The method for determining whether the ionosphere is active is as follows: when the value obtained by the ionospheric correction uncertainty function is greater than the uncertainty threshold, or when the rate of change of the total electron content of the ionosphere is greater than the rate of change threshold, the ionosphere is determined to be active; otherwise, the ionosphere is determined to be inactive.

[0029] When the ionosphere is determined to be active, the user equipment uses an ionosphere-free combined model for positioning.

[0030] When the ionosphere is determined to be inactive, the user equipment uses a non-differential, non-combination model for positioning.

[0031] In one implementation of the first aspect, the method for determining the fixed ambiguity is the Ratio test or the chi-square statistic test.

[0032] Note: The positioning method provided by this invention can establish an adaptive ionospheric correction uncertainty function model based on the spatiotemporal changes of the ionosphere, determine the activity level of the ionosphere based on the ionospheric uncertainty provided by the model, select a suitable estimation strategy to fix the ambiguity, and determine whether the ambiguity is correctly fixed.

[0033] Secondly, the present invention provides an ionospheric adaptive augmentation positioning device that positions user equipment using a global navigation satellite system (GNSS). The GNSS includes a ground-based terminal and a space-based terminal. The ground-based terminal includes multiple ground monitoring stations and a data center, while the space-based terminal includes multiple navigation satellites. The device includes a first determining module, a second determining module, a third determining module, and a positioning module. The first determining module is used by the data center to determine the ionospheric delay information of each of the multiple ground monitoring stations based on an ambiguity fixing method. The ionospheric delay information includes ionospheric tilt delay data between the ground monitoring station and each of the multiple navigation satellites. The second determining module is used by the data center to determine ionospheric delay correction information for each of the multiple ground monitoring stations based on the ionospheric tilt delay information of the multiple ground monitoring stations and an inverse distance linear interpolation method. The ionospheric delay correction information of the ground monitoring station includes ionospheric delay correction data between the ground monitoring station and each of the multiple navigation satellites. The third determining module is used by the data center to determine the ionospheric uncertainty information of each of the multiple navigation satellites based on cross-validation and the ionospheric delay correction information of each of the multiple ground monitoring stations. The positioning module is used by the data center to broadcast the ionospheric uncertainty information of each of the multiple navigation satellites for the positioning of user equipment. The ionospheric uncertainty information is used to determine whether the ionosphere between the navigation satellite and the ground monitoring station is active, and to select a method for positioning the user equipment based on the determination result.

[0034] Thirdly, the present invention provides an electronic device including a processor and a memory coupled to the processor; the memory is used to store computer instructions, and when the electronic device is running, the processor executes the computer instructions stored in the memory to cause the electronic device to perform the method described in the first aspect above or any implementation thereof.

[0035] Fourthly, the present invention provides a computer-readable storage medium including computer program instructions that, when executed by a computer, cause the computer to perform the method described in the first aspect above or any implementation thereof.

[0036] Fifthly, the present invention provides a computer program product, including computer program instructions, which, when executed on a computer, cause the computer to perform the method described in the first aspect above or any implementation thereof.

[0037] The technical effects corresponding to the second to fifth aspects and their possible implementations can be referred to the above description of the technical effects of the first aspect and its possible implementations, and will not be repeated here.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) Based on the linear relationship between the distance between ground monitoring stations and the accuracy of interpolation error, and taking into account the change in the observation elevation angle between the ground monitoring station and the navigation satellite, this invention establishes a linear fitting function for the uncertainty of the ionospheric correction between stations, which can determine the uncertainty information of the ionospheric correction in real time.

[0040] (2) The present invention can achieve adaptive conversion between non-differential non-combination model and ionosphere-free combination model for precise positioning based on the actual situation of the ionosphere: when the ionosphere is calm, the non-differential non-combination model is used to estimate the ionosphere parameters; when the ionosphere is active, the ionosphere-free combination model is used to eliminate the ionosphere parameters and inherit the integer ambiguity parameters that have been fixed in the previous epoch. It can achieve relatively accurate positioning of user equipment in both calm (i.e., inactive) and active ionosphere conditions, thereby improving the positioning accuracy of user equipment. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the global satellite navigation system architecture provided in the embodiments of this application;

[0042] Figure 2 This is one of the schematic diagrams of an ionospheric adaptive enhancement positioning method provided in the embodiments of this application;

[0043] Figure 3 This is a schematic diagram of the station network provided in the embodiments of this application;

[0044] Figure 4 This is a second schematic diagram of an ionospheric adaptive enhancement positioning method provided in the embodiments of this application;

[0045] Figure 5 This is a schematic diagram of the structure of an ionospheric adaptive enhanced positioning device provided in an embodiment of this application. Detailed Implementation

[0046] In the specification and claims of this invention, the terms "first" and "second," etc., are used to distinguish different objects, rather than to describe a specific order of objects.

[0047] In the embodiments of this application, "and / or" indicates a relationship between objects. For example, A and / or B can represent the following three situations: A exists alone, B exists alone, and A and B exist simultaneously.

[0048] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0049] In the description of this invention, unless otherwise stated, "a plurality of" means two or more. For example, a plurality of ground monitoring stations means two or more ground monitoring stations.

[0050] The methods and apparatus provided in this application relate to positioning and can be used to locate user equipment. Specifically, they employ multiple positioning signals emitted by multiple navigation satellites in a global navigation satellite system to locate the user equipment. This can be understood as follows: Figure 1 As shown, a global satellite navigation system includes a ground-based component and a space-based component. The ground-based component includes multiple ground monitoring stations and data centers, while the space-based component includes multiple navigation satellites.

[0051] To address the issue in the background art where existing fitting models or interpolation models such as grids cannot accurately describe the ionospheric changes during periods of high ionospheric activity due to the active and irregular nature of the ionosphere, thus making it difficult to provide high-precision ionospheric delay corrections for real-time positioning of user equipment, resulting in low positioning accuracy, this application provides an ionospheric adaptive augmentation positioning method and apparatus. The data center first calculates the ionospheric delay information of each of multiple ground monitoring stations using an ambiguity fixing method, and then... The ionospheric tilt delay information of the stations and the inverse distance linear interpolation method are used to interpolate the ionospheric delay correction information of each ground monitoring station. Based on the cross-validation method and the ionospheric delay correction information of each ground monitoring station, the ionospheric uncertainty information of each navigation satellite among multiple navigation satellites is obtained. Finally, the ionospheric uncertainty information of each navigation satellite among multiple navigation satellites is broadcast. User equipment can judge whether the ionosphere is active by receiving the ionospheric uncertainty information, and select an appropriate positioning method for the user equipment according to the ionospheric activity, thereby improving the positioning accuracy of the user equipment.

[0052] For example, the positioning method provided in this embodiment of the invention can be executed by an electronic device with processing capabilities, such as a computer or server. Taking a computer as an example, the hardware components of the computer may include: a processor, memory, a network interface, a user interface, a communication bus, etc.

[0053] The processor controls the electronic device to perform related processing and calculation tasks, such as determining ionospheric delay information, ionospheric delay correction information, and ionospheric uncertainty information. The processor may include a central processing unit (CPU) or other processors, and may be single-core or multi-core; for example, the processor may include multiple CPUs.

[0054] Memory is used to store computer instructions and related data, such as ionospheric delay information, ionospheric delay correction information, and ionospheric uncertainty information. Memory can be random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical storage, magnetic disk storage media, or other magnetic storage devices, or any other medium capable of storing program code or data accessible by a computer. Optionally, memory can be integrated into the processor, or it can be independent of the processor.

[0055] A network interface is used for communication between a computer and other devices or communication networks. A network interface can be a transceiver with transmit and receive capabilities. Optionally, a network interface may include standard wired interfaces or wireless interfaces (such as Wi-Fi interfaces, Bluetooth interfaces, and 5G interfaces).

[0056] The communication bus is used to enable communication between different components. For example, the processor, memory, network interface and user interface mentioned above can be interconnected through the communication bus.

[0057] The user interface may include a display screen and an input unit (such as a keyboard). Optionally, the user interface may also include a standard wired interface or a wireless interface.

[0058] Those skilled in the art will understand that the computer described above may include more or fewer components, or combine certain components, or have different component arrangements; the embodiments of this application do not limit this.

[0059] The positioning method provided in this application embodiment locates the user equipment using a global satellite navigation system. For example, such as... Figure 2As shown, the positioning method includes S101-S106.

[0060] S101, Each of the multiple ground monitoring stations receives positioning information from multiple navigation satellites.

[0061] The positioning information includes multiple navigation signals. Each of these navigation signals includes a carrier signal, a ranging code, and a navigation message.

[0062] S102, Multiple ground monitoring stations send the received positioning signals to the data center.

[0063] S103. The data center uses an ambiguity fixing method to determine the ionospheric delay information of each of the multiple ground monitoring stations.

[0064] The ionospheric delay information includes ionospheric tilt delay data between the ground monitoring station and each of the multiple navigation satellites.

[0065] In one implementation, within the precise positioning PPP-RTK algorithm service system, ground monitoring stations extract high-precision zenith tropospheric delay and ionospheric tilt delay information for each satellite based on an ambiguity fixation method. PPP-RTK (Precise Point Positioning Real-Time Kinematic) is a high-precision positioning technology that combines the advantages of PPP (Precise Point Positioning) and RTK (Real-Time Kinematic Positioning), providing centimeter-level positioning accuracy in complex environments. PPP-RTK decomposes the observation errors of the reference station into state-domain errors such as satellite orbit, satellite clock error, satellite phase deviation, ionospheric delay, and tropospheric delay through state domain modeling.

[0066] In the above implementation, the tropospheric delay parameter is first calculated, and then the tropospheric delay information is calculated using the tropospheric delay parameter. Specifically, based on the use of precise satellite orbital clock products and the correctly fixed ambiguity, the tropospheric delay parameter is first extracted through ionospheric-free combination. With the ground monitoring station coordinate information known and residual errors ignored, the calculation formula for the tropospheric delay parameter is as follows.

[0067]

[0068] Among them, T w,r The tropospheric zenith wet delay is to be estimated; This is a mapping function for tropospheric wet delay; dt represents the carrier phase observation. r This refers to the clock bias at the receiver end; For ambiguity parameters; T is the mapping function for tropospheric dry delay; h,r This is the tropospheric zenith dry delay.

[0069] After obtaining the tropospheric delay parameters, the ionospheric tilt path delay of each navigation satellite is further estimated using a non-differential, non-combined model, as shown in the following formula.

[0070]

[0071] in, This represents the ionospheric tilt path delay (i.e., ionospheric delay information) of satellite s at frequency L1, while the delays at other frequencies can be calculated using the conversion factor formula. It can be calculated directly, where j is the frequency number.

[0072] S104. For each of the multiple ground monitoring stations, the data center determines the ionospheric delay correction information of the ground monitoring station based on the ionospheric tilt delay information of the multiple ground monitoring stations and the inverse distance linear interpolation method.

[0073] Ionospheric delay correction information includes ionospheric delay correction data between ground monitoring stations and each of the multiple navigation satellites.

[0074] The specific process of S104 will be described in detail below.

[0075] For each of the multiple ground monitoring stations:

[0076] Using ground monitoring stations as central stations, multiple station networks are constructed based on multiple average distances. Each station network includes multiple ground monitoring stations centered on the central station. Each station network corresponds to an average distance, which is the average of the distances between the multiple ground monitoring stations in the station network and the central station.

[0077] In one application scenario, taking one ground monitoring station out of multiple ground monitoring stations as an example, such as... Figure 3 As shown, the ground monitoring station is used as the central station, and the stations are networked from near to far according to the average distance (d1, d2, d3) to obtain three station networks. Here, d1 is the average distance of the three ground monitoring stations in station network A from the central station, d2 is the average distance of the three ground monitoring stations in station network B from the central station, and d3 is the average distance of the three ground monitoring stations in station network C from the central station.

[0078] The ionospheric delay information of multiple ground monitoring stations in each of the multiple station networks is interpolated using the inverse distance linear interpolation method to obtain the ionospheric delay correction information of the central station; the ionospheric delay correction information of the central station satisfies the following formula.

[0079]

[0080] Where s represents the navigation satellite number, j represents the station network number, and u represents the central station. This represents the ionospheric delay correction data between the central station corresponding to the j-th station network and the navigation satellite numbered s; m represents the number of ground monitoring stations in the j-th station network. This represents the i-th ground monitoring station in the station network. This represents the ionospheric delay information of the i-th ground monitoring station in the network of stations; express The weights, and This represents the distance between the i-th ground monitoring station and the central station in the monitoring network.

[0081] Thus, ionospheric delay correction information for each of the multiple ground monitoring stations was obtained.

[0082] S105. The data center determines the ionospheric uncertainty information of each navigation satellite among multiple navigation satellites based on cross-validation and the ionospheric delay correction information of each ground monitoring station among multiple ground monitoring stations.

[0083] Specifically, for each of the multiple navigation satellites, the ionospheric uncertainty information of the navigation satellite includes the ionospheric uncertainty information between each of the multiple ground monitoring stations and the navigation satellite; the ionospheric uncertainty information between each of the multiple ground monitoring stations and the navigation satellite satisfies the following formula;

[0084]

[0085] Where 's' represents the navigation satellite number and 'I' represents the ground monitoring station number. The ionospheric uncertainty information between the navigation satellite and the ground monitoring station is represented by a0 and a1, which satisfy the following formula;

[0086]

[0087] Where 's' represents the navigation satellite number; This represents the ionospheric uncertainty information between the ground monitoring station in the first station network corresponding to the ground monitoring station and the navigation satellite numbered s, that is, the difference between the ionospheric delay correction data between the ground monitoring station in the first station network corresponding to the ground monitoring station and the navigation satellite numbered s, and the ionospheric tilt delay data between the ground monitoring station and the navigation satellite numbered s. This represents the ionospheric uncertainty information between the ground monitoring station and the navigation satellite numbered s in the j-th station network corresponding to the ground monitoring station. Specifically, it represents the difference between the ionospheric delay correction data and the ionospheric tilt delay data between the ground monitoring station and the navigation satellite numbered s in the j-th station network corresponding to the ground monitoring station; p represents the total number of multiple measurement networks with the ground monitoring station as the central station; p represents the total number of multiple measurement networks with the ground monitoring station as the central station. This represents the ionospheric uncertainty information between the ground monitoring station in the p-th station network and the navigation satellite numbered s, specifically the ionospheric delay correction data between the ground monitoring station and the navigation satellite numbered s, and the difference between the ionospheric tilt delay data between the ground monitoring station and the navigation satellite numbered s; d1 represents the average distance of the first station network; d j d represents the average distance of the network of stations at the j-th station; p This represents the average distance of the network at the p-th station.

[0088] Ionospheric delay correction data between the p-th ground monitoring station and the navigation satellite numbered s in the corresponding ground monitoring station network. It satisfies the following formula.

[0089]

[0090] Where n represents the total number of epochs required to determine the ionospheric delay information of the ground monitoring station; This represents the ionospheric tilt delay data between the ground monitoring station and the navigation satellite numbered 's'. Subtracting these two values ​​yields the difference between the ionospheric tilt delay data and the navigation satellite numbered 's', which is used to calculate the ionospheric correction uncertainty information.

[0091] S106. The data center broadcasts the ionospheric uncertainty information of each of the multiple navigation satellites for use in the positioning of user equipment.

[0092] Among them, ionospheric uncertainty information is used to determine whether the ionosphere between the navigation satellite and the ground monitoring station is active, and to select a method for locating user equipment based on the determination result.

[0093] In one implementation, combined with Figure 2 ,like Figure 4 As shown, the above positioning method also includes S107.

[0094] S107. The user equipment receives the ionospheric uncertainty information of each of the multiple navigation satellites and performs positioning using the ionospheric uncertainty information of each of the multiple navigation satellites.

[0095] S107 will be described in detail below.

[0096] Step 1: For each of the multiple navigation satellites, the user equipment receives the ionospheric uncertainty information of the navigation satellite from the data center, and determines the correction value (also known as the final value) of the ionospheric uncertainty information of the navigation satellite based on the elevation angle of the navigation satellite.

[0097] The correction value satisfies the following formula:

[0098]

[0099] Where 's' represents the navigation satellite number, 'I' represents the ground monitoring station number, and 'ele' represents the elevation angle between the ground monitoring station and the navigation satellite. This represents a correction value for ionospheric uncertainty information between navigation satellites and ground monitoring stations;

[0100] Step 2: The user equipment uses the correction value of the ionospheric uncertainty information of each of the multiple navigation satellites and the ionospheric delay information of each of the multiple ground monitoring stations to determine whether the ambiguity fixing method has successfully fixed the ambiguity.

[0101] Optionally, the method for determining whether ambiguity is fixed can be the Ratio test or the chi-square test. When the Ratio test is used, if the Ratio value is greater than a preset threshold (e.g., 3), the optimal ambiguity solution is considered reliable, meaning the ambiguity is successfully fixed. When the chi-square test is used, if the chi-square value is within a reasonable range, it indicates that the residual meets expectations, and the ambiguity is successfully fixed; conversely, if the chi-square value exceeds the range, it may indicate a problem with the ambiguity fixation. Since both the Ratio test and the chi-square test are common methods in this technical field, this application will not elaborate further on the specific calculation process of the above-mentioned methods.

[0102] Step 3: Select the positioning method for the user equipment based on the judgment result of the ambiguity fixation method.

[0103] When the ambiguity is fixed according to the determination method, the user equipment is positioned using a non-difference non-combination model.

[0104] When the ambiguity determination method is not fixed, the user equipment determines the activity of the ionosphere by using the correction values ​​of the ionospheric uncertainty information from each of the multiple navigation satellites. The method for determining ionospheric activity is as follows: if the value calculated by the ionospheric correction uncertainty function is greater than an uncertainty threshold (e.g., 10 cm), or if the rate of change of the total electron content of the ionosphere is greater than a rate of change threshold (e.g., 0.2 cm / s), the ionosphere is considered active. Otherwise, the ionosphere is considered inactive.

[0105] When the ionosphere is determined to be active, the user equipment uses an ionosphere-free combined model for positioning.

[0106] When the ionosphere is determined to be inactive, the user equipment uses a non-differential, non-combination model for positioning.

[0107] In one implementation, the user's precise position is further calculated by solving the pseudorange and carrier phase observation equations of the non-differential, non-combined model. Specifically, the user equipment receives multiple navigation signals (including carrier signals, ranging codes, and navigation messages) from multiple navigation satellites. The receiver built into the user equipment receives the ranging code signal from the navigation signals, measures the time it takes for the signal to travel from the satellite to the receiver, and then multiplies it by the speed of light to obtain the pseudorange observation value. The user equipment receives positioning enhancement information broadcast by the data center (including satellite clock corrections, receiver clock corrections, ionospheric delay corrections, and tropospheric delay corrections), and then constructs pseudorange and carrier phase observation equations using the pseudorange observation values, carrier signals, and positioning enhancement information. After linearizing the pseudorange and carrier phase observation equations, the least squares method or other optimization algorithms are used to solve the linearized observation equations to obtain the precise position coordinates of the user equipment. In this case, the pseudorange and carrier phase observation equations of the non-differential, non-combined model are as follows.

[0108]

[0109] in, For pseudo-range, For carrier phase, Let c be the actual geometric distance between the user equipment and the navigation satellite, and dt be the speed of light. r For the clock delay of the receiver, dt s For the clock delay of navigation satellites; κ represents the total tropospheric delay. f The ionospheric delay factor is... d is the ionospheric delay corresponding to frequency f1; r,f For pseudorange hardware delay at the receiver end (i.e., user equipment); For pseudorange hardware delay of navigation satellites; ε P,f The residual is the pseudorange; the ionospheric delay at other frequencies can be obtained through the ionospheric delay coefficient κ.f Calculated, i.e. N f For carrier phase ambiguity information; λ f The wavelength of frequency f; b r,f The phase hardware delay at the receiver end; For the phase hardware delay at the satellite end; ε L,f s represents the phase residual; s represents the satellite number.

[0110] In another implementation, the user's precise location is obtained by further solving the pseudorange and carrier phase observation equations of the ionosphere-free combined model. The pseudorange and carrier phase observation equations under the ionosphere-free combined model are as follows.

[0111]

[0112] in, Indicates pseudo-range and Indicates carrier phase and P IF L IF These are ionospherically uncombined observations of pseudorange and carrier wave, respectively. The observation equations after this combination no longer contain ionospheric delay terms; the other parameters have the same meaning in the unequal and non-combined models.

[0113] Understandably, the non-differential, non-combined model directly utilizes the raw observations from the receivers within the ground monitoring station, meaning it does not perform inter-station or inter-satellite differential analysis, nor does it perform specific combinations of observations from different frequencies. The non-differential, non-combined model uses the original observation equations for pseudorange and carrier phase, preserving all observation information.

[0114] In processing ionospheric parameters, non-differential, non-combined models are relatively complex, requiring precise modeling of the impact of ionospheric delay on pseudorange and carrier phase observations. This typically involves using empirical models or external ionospheric data to estimate the ionospheric delay. In high-precision positioning, the spatiotemporal variations of the ionosphere must be considered, necessitating more refined modeling and estimation of the ionospheric delay. Ionospheric-free combined models, however, directly eliminate the influence of ionospheric delay through the combination of observations, eliminating the need for separate modeling and estimation of the ionospheric delay. This approach effectively avoids the impact of ionospheric delay on positioning results, improving stability and accuracy, even under conditions of strong ionospheric activity and significant ionospheric delay variations.

[0115] Therefore, in the positioning method provided in this application embodiment, the activity of the ionosphere is determined based on ionospheric uncertainty information (i.e., strong ionospheric activity and large changes in ionospheric delay). A model suitable for the current ionospheric condition is selected from both a non-differential, non-combined model and an ionospheric-free combined model to locate the user equipment. Specifically, when ionospheric activity is weak, a non-differential, non-combined model is used to fully utilize the information from the original observations and obtain higher positioning accuracy; while when ionospheric activity is strong, the method switches to an ionospheric-free combined model to ensure the stability and reliability of positioning. This method achieves complementarity between the two models, thereby improving the positioning accuracy of the user equipment.

[0116] Accordingly, this application provides an ionospheric adaptive enhanced positioning device that positions user equipment using a global navigation satellite system. The global navigation satellite system includes a ground-based terminal and a space-based terminal. The ground-based terminal includes multiple ground monitoring stations and a data center, while the space-based terminal includes multiple navigation satellites. For example... Figure 5 As shown, it includes a first determining module 501, a second determining module 502, a third determining module 503, and a positioning module 504.

[0117] The first determining module 501 is used by the data center to determine the ionospheric delay information of each of the multiple ground monitoring stations based on an ambiguity fixing method; the ionospheric delay information includes ionospheric tilt delay data between the ground monitoring station and each of the multiple navigation satellites. For example, the first determining module 501 is used to implement S103 of the above positioning method.

[0118] The second determining module 502 is used to, for each of the multiple ground monitoring stations, determine the ionospheric delay correction information of the ground monitoring station based on the ionospheric tilt delay information of the multiple ground monitoring stations and the inverse distance linear interpolation method; the ionospheric delay correction information includes the ionospheric delay correction data between the ground monitoring station and each of the multiple navigation satellites. For example, the second determining module 502 is used to implement S104 of the above positioning method.

[0119] The third determining module 503 is used by the data center to determine the ionospheric uncertainty information of each navigation satellite among multiple navigation satellites based on cross-validation and the ionospheric delay correction information of each ground monitoring station among multiple ground monitoring stations. For example, the third determining module 503 is used to implement S105 of the above positioning method.

[0120] The positioning module 504 is used by the data center to broadcast the ionospheric uncertainty information of each of the multiple navigation satellites for the positioning of user equipment. The ionospheric uncertainty information is used to determine whether the ionosphere between the navigation satellite and the ground monitoring station is active, and to select a method for positioning the user equipment based on the determination result.

[0121] Each module of the above positioning device can also be used to perform other steps in the above method embodiments. All relevant content involved in the above method embodiments can be referred to in the functional description of the corresponding functional module, and will not be repeated here.

[0122] This application also provides an electronic device, including: a processor and a memory coupled to the processor; the memory is used to store computer instructions, and when the electronic device is running, the processor executes the computer instructions stored in the memory to cause the electronic device to perform the methods in the above embodiments. The processor can implement the first determining module 501, the second determining module 502, the third determining module 503, and the positioning module 504 described above; the memory can also be used to store ionospheric delay information, ionospheric delay correction information, and ionospheric uncertainty information, etc.

[0123] This application also provides a computer-readable storage medium including a computer program that, when run on a computer, performs the methods described in the above embodiments.

[0124] This application also provides a computer program product, which includes computer program instructions that, when run on a computer, execute the methods described in the above embodiments.

[0125] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions in the embodiments of this application.

Claims

1. An ionospheric adaptive enhancement positioning method, characterized in that, Positioning user equipment using a global navigation satellite system, wherein the global navigation satellite system includes a ground terminal and a space terminal, the ground terminal including multiple ground monitoring stations and a data center, and the space terminal including multiple navigation satellites; the method includes: The data center determines the ionospheric delay information of each of the plurality of ground monitoring stations based on the ambiguity fixing method; the ionospheric delay information includes the ionospheric tilt delay data between the ground monitoring station and each of the plurality of navigation satellites; For each of the plurality of ground monitoring stations, the data center determines the ionospheric delay correction information of the ground monitoring station based on the ionospheric tilt delay information of the plurality of ground monitoring stations and the inverse distance linear interpolation method; the ionospheric delay correction information of the ground monitoring station includes the ionospheric delay correction data between the ground monitoring station and each of the plurality of navigation satellites; The data center determines the ionospheric uncertainty information of each of the plurality of navigation satellites based on cross-validation and ionospheric delay correction information from each of the plurality of ground monitoring stations. For each of the plurality of navigation satellites, the user equipment receives the ionospheric uncertainty information of the navigation satellite from the data center and determines a correction value for the ionospheric uncertainty information of the navigation satellite according to the elevation angle of the navigation satellite. The correction value satisfies the following formula: Where 's' represents the navigation satellite number, 'I' represents the ground monitoring station number, and 'ele' represents the elevation angle between the ground monitoring station and the navigation satellite. This represents a correction value for the ionospheric uncertainty information between the navigation satellite and the ground monitoring station; The data center broadcasts the ionospheric uncertainty information of each of the plurality of navigation satellites for the positioning of the user equipment; wherein, the ionospheric uncertainty information is used to determine whether the ionosphere between the navigation satellite and the ground monitoring station is active, and selects a method for positioning the user equipment based on the determination result.

2. The method as described in claim 1, characterized in that, For each of the plurality of ground monitoring stations, the data center determines the ionospheric delay correction information of the ground monitoring station based on the ionospheric delay information of the plurality of ground monitoring stations and the inverse distance linear interpolation method, including: For each of the plurality of ground monitoring stations: Using the ground monitoring station as the central station, multiple station networks are constructed based on multiple average distances; wherein, each of the multiple station networks includes multiple ground monitoring stations centered on the central station; each station network corresponds to an average distance, which is the average of the distances between the multiple ground monitoring stations in the station network and the central station; The ionospheric delay information of multiple ground monitoring stations in each of the multiple station networks is interpolated using the inverse distance linear interpolation method to obtain the ionospheric delay correction information of the central station; the ionospheric delay correction information of the central station satisfies the following formula; Where s represents the navigation satellite number, j represents the station network number, and u represents the central station. This represents the ionospheric delay correction data between the central station corresponding to the j-th station network and the navigation satellite numbered s; m represents the number of ground monitoring stations in the j-th station network. This represents the i-th ground monitoring station in the station network. This represents the ionospheric delay information of the i-th ground monitoring station in the network of stations; express The weight, and This represents the distance between the i-th ground monitoring station in the monitoring network and the central station; Ionospheric delay correction information is obtained for each of the plurality of ground monitoring stations.

3. The method as described in claim 1 or 2, characterized in that, For each of the plurality of navigation satellites, the ionospheric uncertainty information of the navigation satellite includes the ionospheric uncertainty information between each of the plurality of ground monitoring stations and the navigation satellite; The ionospheric uncertainty information between each of the plurality of ground monitoring stations and the navigation satellite satisfies the following formula; Where 's' represents the navigation satellite number and 'I' represents the ground monitoring station number. The ionospheric uncertainty information between the navigation satellite and the ground monitoring station is represented by a0 and a1, which satisfy the following formula; Where 's' represents the navigation satellite number; This indicates the ionospheric uncertainty information between the ground monitoring station and the navigation satellite numbered s in the first station network corresponding to the ground monitoring station; This represents the ionospheric uncertainty information between the ground monitoring station and the navigation satellite numbered s in the j-th station network corresponding to the ground monitoring station; p represents the total number of multiple measurement networks in which the ground monitoring station serves as the central station; This represents the ionospheric uncertainty information between the ground monitoring station in the p-th station network corresponding to the ground monitoring station and the navigation satellite numbered s; d1 represents the average distance of the first station network; d j d represents the average distance of the j-th station network; p This represents the average distance of the p-th station network; The following formula must be satisfied; Where n represents the total number of epochs required to determine the ionospheric delay information of the ground monitoring station; This represents the ionospheric tilt delay data between the ground monitoring station and the navigation satellite numbered s.

4. The method as described in claim 1, characterized in that, The method for locating the user equipment is either an ionosphere-free combined model or a non-difference non-combined model.

5. The method as described in claim 1, characterized in that, The user equipment uses the correction value of the ionospheric uncertainty information of each of the plurality of navigation satellites and the ionospheric delay information of each of the plurality of ground monitoring stations to determine whether the ambiguity fixing method is ambiguity fixed; When it is determined that the ambiguity is fixed by the ambiguity fixing method, the user equipment performs positioning using a non-difference non-combination model; When the ambiguity fixing method is determined to be unstable, the user equipment determines whether the ionosphere is active by using the correction value of the ionospheric uncertainty information of each of the plurality of navigation satellites. The method for determining whether the ionosphere is active is as follows: when the value obtained by calculating the ionospheric correction uncertainty function is greater than the uncertainty threshold, or when the rate of change of the total electron content of the ionosphere is greater than the rate of change threshold, the ionosphere is determined to be active; otherwise, the ionosphere is determined to be inactive. When the ionosphere is determined to be active, the user equipment uses an ionosphere-free composite model for positioning. When the ionosphere is determined to be inactive, the user equipment uses a non-differential non-combination model for positioning.

6. The method as described in claim 5, characterized in that, The method for determining the fixed ambiguity is either the Ratio test or the chi-square statistic test.

7. An ionospheric adaptive enhanced positioning device, characterized in that, The device locates user equipment using a global satellite navigation system, which includes a ground terminal and a space terminal. The ground terminal includes multiple ground monitoring stations and a data center, and the space terminal includes multiple navigation satellites. The device includes a first determination module, a second determination module, a third determination module, and a positioning module. The first determining module is used to determine the ionospheric delay information of each of the plurality of ground monitoring stations based on the ambiguity fixing method; the ionospheric delay information includes ionospheric tilt delay data between the ground monitoring station and each of the plurality of navigation satellites; The second determining module is used to, for each of the plurality of ground monitoring stations, determine the ionospheric delay correction information of the ground monitoring station based on the ionospheric tilt delay information of the plurality of ground monitoring stations and the inverse distance linear interpolation method; the ionospheric delay correction information of the ground monitoring station includes the ionospheric delay correction data between the ground monitoring station and each of the plurality of navigation satellites; The third determining module is used to determine the ionospheric uncertainty information of each of the multiple navigation satellites based on the cross-validation method and the ionospheric delay correction information of each of the multiple ground monitoring stations. For each of the plurality of navigation satellites, the user equipment receives the ionospheric uncertainty information of the navigation satellite from the data center, and determines a correction value for the ionospheric uncertainty information of the navigation satellite based on the elevation angle of the navigation satellite; the correction value satisfies the following formula: Where 's' represents the navigation satellite number, 'I' represents the ground monitoring station number, and 'ele' represents the elevation angle between the ground monitoring station and the navigation satellite. This represents a correction value for the ionospheric uncertainty information between the navigation satellite and the ground monitoring station; The positioning module is used by the data center to broadcast the ionospheric uncertainty information of each of the plurality of navigation satellites for the positioning of the user equipment; wherein the ionospheric uncertainty information is used to determine whether the ionosphere between the navigation satellite and the ground monitoring station is active, and to select a method for positioning the user equipment based on the determination result.

8. An electronic device, characterized in that, The device includes a processor and a memory coupled to the processor; the memory is used to store computer instructions, which, when the electronic device is running, are executed by the processor to cause the electronic device to perform the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, It includes computer program instructions that, when executed by a computer, cause the computer to perform the method as described in any one of claims 1 to 6.

10. A computer program product, characterized in that, It includes computer program instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 6.

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