Ionized layer adaptive enhanced positioning method and device

Abstract

The invention provides an ionosphere adaptive enhanced positioning method and device, belongs to the technical field of positioning, and can judge whether an ionosphere is active or not according to ionosphere uncertainty information and select a more appropriate positioning method for user equipment according to a judgment result, thereby improving the positioning precision of the user equipment. The method determines ionosphere uncertainty information of each navigation satellite in the plurality of navigation satellites based on a cross validation method and ionosphere delay correction information of each ground monitoring station in the plurality of ground monitoring stations. The ionosphere uncertainty information is used for judging whether an ionosphere between a navigation satellite and a ground monitoring station is active or not, and a method for positioning the user equipment is selected according to a judgment result, so that positioning of the user equipment is realized.

Description

Technical Field

[0001] The present invention relates to the field of positioning technology, and in particular, to an ionosphere adaptive enhanced positioning method and device. Background Art

[0002] The Global Navigation Satellite System (GNSS) is a global positioning system based on satellite signals, which can provide high-precision positioning services for users. In existing methods (for example, PPP-RTK), positioning signals of navigation satellites are often used in combination with positioning enhancement information to accurately position user equipment. Among them, the positioning enhancement information includes correction numbers such as ephemeris error correction numbers, satellite clock error correction numbers, and ionospheric delay correction numbers.

[0003] However, due to the active and irregular variation characteristics of the ionosphere, existing fitting models or interpolation models such as grids still cannot accurately describe the ionospheric variation characteristics during the active period of the ionosphere. Therefore, when performing real-time positioning of user equipment during the active period of the ionosphere, it is difficult to obtain high-precision ionospheric delay correction numbers, and further, the positioning accuracy of the positioning method using ionospheric delay correction numbers is not high. Summary of the Invention

[0004] The present invention provides an ionosphere adaptive enhanced positioning method and device, which can judge whether the ionosphere is active through ionospheric uncertainty information, and select a more suitable positioning method for user equipment according to the judgment result, thereby improving the positioning accuracy of user equipment.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides an ionospheric adaptive enhanced positioning method for positioning a user device through a global satellite navigation system. The global satellite navigation system includes a ground end and a space end. The ground end includes a plurality of ground monitoring stations and a data center, and the space end includes a plurality of navigation satellites. The method includes: The data center determines the ionospheric delay information of each ground monitoring station among the plurality of ground monitoring stations based on a ambiguity fixing method. The ionospheric delay information includes the ionospheric tilt delay data between the ground monitoring station and each navigation satellite among the plurality of navigation satellites. For each ground monitoring station among 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 navigation satellite among the plurality of navigation satellites. The data center determines the ionospheric uncertainty information of each navigation satellite among the plurality of navigation satellites based on the cross-validation method and the ionospheric delay correction information of each ground monitoring station among the plurality of ground monitoring stations. The data center broadcasts the ionospheric uncertainty information of each navigation satellite among the plurality of navigation satellites for positioning the user device; wherein, the ionospheric uncertainty information is used to determine whether the ionosphere between the navigation satellite and the ground monitoring station is active, and select a positioning method for the user device according to the determination result.

[0007] In an implementation manner of the first aspect, for each ground monitoring station among 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:

[0008] For each ground monitoring station among the plurality of ground monitoring stations:

[0009] Taking the ground monitoring station as the central station, constructing a plurality of station networks according to a plurality of average distances; wherein, each of the plurality of station networks includes a plurality of ground monitoring stations centered on the central station; each station network corresponds to an average distance, and the average distance is the average value of the distances between the plurality of ground monitoring stations and the central station in the station network;

[0010] Using the inverse distance linear interpolation method to interpolate the ionospheric delay information of the plurality of ground monitoring stations in each of the plurality of station networks 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] wherein, s represents the number of the navigation satellite, j represents the number of the station network, and u represents the central station, denotes 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. denotes the i-th ground monitoring station in the station network. denotes the ionospheric delay information of the i-th ground monitoring station in the station network. denotes the weight of, and denotes the distance between the i-th ground monitoring station in the station network and the central station.

[0013] Obtain the ionospheric delay correction information of each ground monitoring station among multiple ground monitoring stations.

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

[0015]

[0016] where s represents the number of the navigation satellite, and I represents the number of the ground monitoring station. denotes the ionospheric uncertainty information between the navigation satellite and the ground monitoring station, a 0 and a 1 satisfy the following formula;

[0017]

[0018] where s represents the number of the navigation satellite; denotes the ionospheric uncertainty information between the ground monitoring station in the 1st station network corresponding to the ground monitoring station and the navigation satellite numbered s; denotes the ionospheric uncertainty information between the ground monitoring station in the j-th station network corresponding to the ground monitoring station and the navigation satellite numbered s; p represents the total number of multiple station networks with the ground monitoring station as the central station; denotes 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; d 1 denotes the average distance of the 1st station network; d j denotes the average distance of the j-th station network; d p denotes the average distance of the p-th station network;

[0019] satisfies the following formula;

[0020]

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

[0022] In one implementation manner 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 sent by the data center, and determines the correction value of the ionospheric uncertainty information of the navigation satellite according to the elevation angle of the navigation satellite; the correction value satisfies the following formula:

[0024]

[0025] Among them, s represents the number of the navigation satellite, I represents the number of the ground monitoring station, ele represents the elevation angle between the ground monitoring station and the navigation satellite, represents the correction value of the ionospheric uncertainty information between the navigation satellite and the ground monitoring station;

[0026] 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 ground monitoring station among the multiple ground monitoring stations to determine whether the ambiguity fixing method is ambiguity fixed;

[0027] When it is determined that the ambiguity fixing method is ambiguity fixed, the user equipment performs positioning through a non-differential and non-combined model;

[0028] When it is determined that the ambiguity fixing method is not ambiguity fixed, the user equipment determines whether the ionosphere is active through 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: when the value calculated by the ionospheric correction uncertainty function is greater than the uncertainty threshold, or when the total electron content change rate of the ionosphere is greater than the change rate threshold, it is determined that the ionosphere is active; otherwise, it is determined that the ionosphere is inactive;

[0029] When it is determined that the ionosphere is active, the user equipment performs positioning through an ionosphere-free combination model;

[0030] When it is determined that the ionosphere is inactive, the user equipment performs positioning through a non-differential and non-combined model.

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

[0032] Description: The positioning method provided by the present invention can establish an adaptive ionospheric correction uncertainty function model according to the spatio-temporal changes of the ionosphere, and 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] In a second aspect, the present invention provides an ionospheric adaptive enhanced positioning device for positioning a user device through a global satellite navigation system. The global satellite navigation system includes a ground end and a space end. The ground end includes a plurality of ground monitoring stations and a data center, and the space end includes a plurality of navigation satellites. The device includes a first determination module, a second determination module, a third determination module, and a positioning module. The first determination module is configured to: the data center determines the ionospheric delay information of each ground monitoring station among the plurality of ground monitoring stations based on a ambiguity fixing method; the ionospheric delay information includes the ionospheric tilt delay data between the ground monitoring station and each navigation satellite among the plurality of navigation satellites. The second determination module is configured to: for each ground monitoring station among 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 navigation satellite among the plurality of navigation satellites. The third determination module is configured to: the data center determines the ionospheric uncertainty information of each navigation satellite among the plurality of navigation satellites based on the cross-validation method and the ionospheric delay correction information of each ground monitoring station among the plurality of ground monitoring stations. The positioning module is configured to: the data center broadcasts the ionospheric uncertainty information of each navigation satellite among the plurality of navigation satellites for positioning the user device; wherein, the ionospheric uncertainty information is used to determine whether the ionosphere between the navigation satellite and the ground monitoring station is active, and select a method for positioning the user device according to the determination result.

[0034] In a third aspect, 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 runs, the processor executes the computer instructions stored in the memory so that the electronic device executes the method described in the first aspect or any one of its implementation manners above.

[0035] In a fourth aspect, the present invention provides a computer-readable storage medium, including computer program instructions, and when the computer program instructions are executed by a computer, the computer is caused to execute the method described in the first aspect or any one of its implementation manners above.

[0036] Fifth aspect, the present invention provides a computer program product, including computer program instructions, when the computer program instructions run on a computer, enabling the computer to execute the method described in the above first aspect or any one of its implementation manners.

[0037] For the technical effects corresponding to the above second aspect to fifth aspect and their possible implementation manners, reference can be made to the description of the technical effects of the first aspect and its possible implementation manners above, which will not be elaborated here.

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

[0039] (1) Based on the linear relationship between the spacing of ground monitoring stations and the interpolation error accuracy, and considering the change of the observation elevation angle between the ground monitoring stations and navigation satellites, the present invention establishes a linear fitting function for the uncertainty of the ionospheric correction number between stations, and can determine the uncertainty information of the ionospheric correction number in real time;

[0040] (2) The present invention can realize the adaptive conversion between the non-differential non-combination model and the ionosphere-free combination model during precise positioning according to the actual situation of the ionosphere: when the ionosphere is quiet, the non-differential non-combination model is used for processing to estimate the ionospheric parameters; when the ionosphere is active, the ionosphere-free combination model is used to eliminate the ionospheric parameters, and at the same time inherit the integer ambiguity parameters that have been fixed in the previous epochs, and can achieve relatively accurate positioning of the user equipment in both the quiet (i.e., inactive) and active cases of the ionosphere, thereby improving the positioning accuracy of the user equipment. Description of the Drawings

[0041] Figure 1 is a schematic diagram of the global satellite navigation system architecture provided by an embodiment of the present application;

[0042] Figure 2 is one of the schematic diagrams of an ionospheric adaptive enhanced positioning method provided by an embodiment of the present application;

[0043] Figure 3 is a schematic diagram of the station network provided by an embodiment of the present application;

[0044] Figure 4 is the other schematic diagram of an ionospheric adaptive enhanced positioning method provided by an embodiment of the present application;

[0045] Figure 5 is a schematic diagram of the structure of an ionospheric adaptive enhanced positioning device provided by an embodiment of the present application. Detailed Embodiments

[0046] In the description and claims of the present invention, terms such as "first" and "second" are used to distinguish different objects, rather than to describe a specific order of objects.

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

[0048] In the embodiments of this application, words such as "exemplary" or "for example" are used to give examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0049] In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" refers to two or more. For example, a plurality of ground monitoring stations refers to two or more ground monitoring stations.

[0050] The method and device provided in the embodiments of this application relate to positioning and can be used to position a user equipment. Specifically, multiple positioning signals sent by multiple navigation satellites in the global satellite navigation system are used to position the user equipment. It can be understood that, as Figure 1 shown, the global satellite navigation system includes a ground segment and a space segment. The ground segment includes a plurality of ground monitoring stations and a data center, and the space segment includes a plurality of navigation satellites.

[0051] To solve the problem in the background technology that due to the active and irregular variation characteristics of the ionosphere, existing interpolation models such as fitting models or grids still cannot accurately describe the ionospheric variation characteristics during the active period of the ionosphere. Therefore, it is difficult to provide high-precision ionospheric delay correction numbers in real-time positioning of user equipment, resulting in low positioning accuracy of the user equipment. The embodiments of this application provide an ionospheric adaptive enhanced positioning method and device. The data center first calculates the ionospheric delay information of each ground monitoring station among a plurality of ground monitoring stations through an ambiguity fixing method, and then interpolates to obtain the ionospheric delay correction information of each ground monitoring station through the ionospheric tilt delay information of each ground monitoring station among the plurality of ground monitoring stations and the inverse distance linear interpolation method. 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 a plurality of navigation satellites is obtained. Finally, the ionospheric uncertainty information of each navigation satellite among the plurality of navigation satellites is broadcast, and the user equipment can judge whether the ionosphere is active based on the received ionospheric uncertainty information, and select a suitable positioning method for the user equipment according to whether the ionosphere is active, thereby improving the positioning accuracy of the user equipment.

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

[0053] Among them, the processor is used to control the electronic device to execute relevant processing and computing tasks. For example, to determine ionospheric delay information, ionospheric delay correction information, ionospheric uncertainty information, etc. The processor can include a central processing unit (CPU) or other processors. The processor can be single-core or multi-core. For example, the processor can include multiple CPUs.

[0054] The memory is used to store computer instructions and related data. For example, to store ionospheric delay information, ionospheric delay correction information, ionospheric uncertainty information, etc. The memory can be a random access memory (RAM), a read only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, or an optical memory, a magnetic disk storage medium, or any other magnetic storage device, or any other medium capable of storing program code or data that can be accessed by a computer. Optionally, the memory can be integrated within the processor, or the memory can be independent of the processor.

[0055] The network interface is used for the computer to communicate with other devices or communication networks. The network interface can be a transceiver with sending and receiving functions. Optionally, the network interface can include a standard wired interface, a wireless interface (such as a WI-FI interface, a Bluetooth interface, a 5G interface).

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

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

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

[0059] In the positioning method provided in the embodiments of the present application, the user equipment is positioned through a global satellite navigation system. Exemplarily, such as Figure 2As shown, the positioning method includes S101 - S106.

[0060] S101. Each ground monitoring station among multiple ground monitoring stations receives positioning information sent by multiple navigation satellites.

[0061] Among them, the positioning information includes multiple navigation signals. Each navigation signal among the multiple navigation signals includes: a carrier signal, a ranging code, and navigation telegrams.

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

[0063] S103. The data center determines the ionospheric delay information of each ground monitoring station among the multiple ground monitoring stations based on an ambiguity fixing method.

[0064] Among them, the ionospheric delay information includes the ionospheric tilt delay data between the ground monitoring station and each navigation satellite among the multiple navigation satellites.

[0065] In one implementation, in a precise positioning PPP - RTK algorithm service system, the ground monitoring station extracts high - precision zenith tropospheric delay and slant - path ionospheric tilt delay information of each satellite based on an ambiguity fixing method. Among them, 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), and can provide centimeter - level positioning accuracy in complex environments. PPP - RTK decomposes the observed value errors of the reference station into state quantity errors such as satellite orbits, satellite clock errors, satellite phase biases, ionospheric delays, and tropospheric delays through state - domain modeling.

[0066] In the above implementation, after calculating the tropospheric delay parameters, the tropospheric delay information is calculated through the tropospheric delay parameters. Specifically, on the basis of using precise satellite orbit and clock products and the ambiguity being correctly fixed, the tropospheric delay parameters are first extracted through ionosphere - free combination. When the coordinate information of the ground monitoring station is known and residual errors are ignored, the calculation formula of the tropospheric delay parameters is as follows.

[0067]

[0068] Among them, T w,r is the tropospheric zenith wet delay to be estimated; is the mapping function of the tropospheric wet delay; is the carrier - phase observation value; dt r is the clock error at the receiver end; is the ambiguity parameter; is the mapping function of tropospheric dry delay; T h,r is the tropospheric zenith dry delay.

[0069] After obtaining the tropospheric delay parameters, the ionospheric slant path delay of each navigation satellite is further estimated using the non-differenced and non-combined model, and the formula is as follows.

[0070]

[0071] Where is the ionospheric slant path delay of satellite s at frequency L1 (i.e., ionospheric delay information), and the delays at other frequencies can be directly calculated through the conversion coefficient formula , 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 slant delay information of the multiple ground monitoring stations and the inverse distance linear interpolation method.

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

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

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

[0076] Taking the ground monitoring station as the central station, multiple station networks are constructed according to multiple average distances; among them, each of the multiple station networks includes multiple ground monitoring stations centered on the central station; each station network corresponds to an average distance, and the average distance is the average of the distances between the multiple ground monitoring stations and the central station in the station network.

[0077] In an application scenario, taking one of the multiple ground monitoring stations as an example, as Figure 3 shown, taking this ground monitoring station as the central station, networking is carried out from near to far according to the average distances (d 1 , d 2 , d 3 ), and three station networks are obtained. Among them, d 1 is the average distance between the three ground monitoring stations of station network A and the central station, d 2 is the average distance between the three ground monitoring stations of station network B and the central station, and d 3 is the average distance between the three ground monitoring stations of station network C and the central station.

[0078] The ionospheric delay information of multiple ground monitoring stations in each station network 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 number of the navigation satellite, j represents the number of the station network, and u represents the central station, 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, represents the i-th ground monitoring station in the station network, represents the ionospheric delay information of the i-th ground monitoring station in the station network; represents the weight of, and represents the distance between the i-th ground monitoring station in the station network and the central station.

[0081] Thus, the ionospheric delay correction information of each ground monitoring station among the multiple ground monitoring stations is obtained.

[0082] S105. The data center determines 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 ground monitoring station among the 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 ground monitoring station among the multiple ground monitoring stations and the navigation satellite; the ionospheric uncertainty information between each ground monitoring station among the multiple ground monitoring stations and the navigation satellite satisfies the following formula;

[0084]

[0085] where s represents the number of the navigation satellite, and I represents the number of the ground monitoring station, represents the ionospheric uncertainty information between the navigation satellite and the ground monitoring station, a 0 and a 1 satisfy the following formula;

[0086]

[0087] where s represents the number of the navigation satellite; It 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; It represents the ionospheric uncertainty information between the ground monitoring station in the j-th 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 j-th 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; p represents the total number of multiple station networks with the ground monitoring station as the central station; p represents the total number of multiple station networks with the ground monitoring station as the central station; It 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, that is, the difference between the ionospheric delay correction data between the ground monitoring station in the p-th 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; d 1 It represents the average distance of the first station network; d j It represents the average distance of the j-th station network; d p It represents the average distance of the p-th station network.

[0088] The ionospheric delay correction data between the ground monitoring station in the p-th station network corresponding to the ground monitoring station and the navigation satellite numbered s Satisfies the following formula.

[0089]

[0090] Among them, n represents the total number of epochs required to determine the ionospheric delay information of the ground monitoring station; It represents the ionospheric tilt delay data between the ground monitoring station and the navigation satellite numbered s. The difference between the two can obtain the difference between the ionospheric tilt delay data between the ground monitoring station 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 navigation satellite among multiple navigation satellites for the positioning of user equipment.

[0092] Among them, the ionospheric uncertainty information is used to judge whether the ionosphere between the navigation satellite and the ground monitoring station is active, and select a method for positioning the user equipment according to the judgment result.

[0093] In one implementation, in combination with Figure 2 , such as Figure 4 shown, the above positioning method further includes S107.

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

[0095] The following provides a detailed description of S107.

[0096] Step 1. For each of the multiple navigation satellites, the user equipment receives the ionospheric uncertainty information of the navigation satellite sent by the data center, and determines the correction value (which can also be referred to as the final value) of the ionospheric uncertainty information of the navigation satellite according to the elevation angle of the navigation satellite.

[0097] The correction value satisfies the following formula:

[0098]

[0099] where s represents the number of the navigation satellite, I represents the number of the ground monitoring station, ele represents the elevation angle between the ground monitoring station and the navigation satellite, represents the correction value of the ionospheric uncertainty information between the navigation satellite and the ground monitoring station;

[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 successfully fixes the ambiguity.

[0101] Optionally, the method for judging the ambiguity fixing is the Ratio test method or the chi-square statistic test method. When the method for judging the ambiguity fixing is the Ratio test method, when the Ratio value is greater than a preset threshold (for example, 3), it is considered that the optimal ambiguity solution is reliable, that is, the ambiguity is successfully fixed. When the method for judging the ambiguity fixing is the chi-square statistic test method, if the chi-square value is within a reasonable range, it indicates that the residuals meet the expectations and the ambiguity fixing is successful; otherwise, if the chi-square value exceeds the range, it may indicate that there is a problem with the ambiguity fixing. Since both the Ratio test method and the chi-square statistic test method are common methods in the technical field, the embodiments of the present application do not further elaborate on the specific calculation processes of the above judgment methods.

[0102] Step 3. Select the positioning method of the user equipment according to the judgment result of the ambiguity fixing method.

[0103] When it is determined that the ambiguity fixing method fixes the ambiguity, the user equipment performs positioning through the undifferenced and non-combined model.

[0104] When it is determined that the ambiguity fixing method does not fix the ambiguity, the user equipment determines whether the ionosphere is active by using the correction value of the ionospheric uncertainty information of each of multiple navigation satellites. Among them, 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 (for example, 10 cm), or the total electron content change rate of the ionosphere is greater than the change rate threshold (for example, 0.2 cm / s), it is determined that the ionosphere is active. Otherwise, it is determined that the ionosphere is inactive.

[0105] When it is determined that the ionosphere is active, the user equipment performs positioning by using the ionosphere-free combination model.

[0106] When it is determined that the ionosphere is inactive, the user equipment performs positioning by using the undifferenced and non-combined model.

[0107] In one implementation, the precise position of the user is further calculated through the pseudorange and carrier phase observation equations of the undifferenced and non-combined model. Specifically, the user equipment receives multiple navigation signals (including carrier signals, ranging codes, and navigation messages) sent by multiple navigation satellites. The receiver built in the user equipment measures the time for the signal to propagate from the satellite to the receiver by receiving the ranging code signal in the navigation signal, and then multiplies it by the speed of light to obtain the pseudorange observation value. The user equipment receives the positioning enhancement information (including satellite clock error correction, receiver clock error correction, ionospheric delay correction, and tropospheric delay correction) broadcast by the data center, and then constructs the pseudorange and carrier phase observation equations by using the pseudorange observation value, carrier signal, and positioning enhancement information. After linearizing the pseudorange and carrier phase observation equations, finally, 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 undifferenced and non-combined model are as follows.

[0108]

[0109] Among them, is the pseudorange, is the carrier phase, is the true geometric distance between the user equipment and the navigation satellite, c is the speed of light, dt r is the clock error delay of the receiver, dt s is the clock error delay of the navigation satellite; is the total tropospheric delay; κf is the ionospheric delay coefficient, is the frequency f 1 corresponding ionospheric delay; d r,f is the pseudorange hardware delay at the receiver end (i.e., the user equipment); is the pseudorange hardware delay of the navigation satellite; ε P,f is the residual of the pseudorange; the ionospheric delay of other frequencies can be calculated through the ionospheric delay coefficient k f which is calculated as N f is the carrier phase ambiguity information; λ f is the wavelength of frequency f; b r,f is the phase hardware delay at the receiver end; is the phase hardware delay at the satellite end; ε L,f is the residual of the phase; s is the satellite number.

[0110] In another implementation, the precise position of the user is further calculated through the pseudorange and carrier phase observation equations of the ionosphere-free combination model. The pseudorange and carrier phase observation equations under the ionosphere-free combination model are as follows.

[0111]

[0112] where represents the pseudorange and represents the carrier phase and P IF 、L IF are the ionosphere-free combination observations of the pseudorange and the carrier respectively. After this combination, the observation equation no longer contains the ionospheric delay term; other parameters have the same meaning as in the undifferenced and non-combined model.

[0113] It can be understood that the undifferenced and non-combined model directly uses the original observations of the receivers in the ground monitoring stations, that is, it does not perform inter-station and inter-satellite differencing, and does not perform specific combinations on the observations of different frequencies either. The undifferenced and non-combined model uses the original observation equations of the pseudorange and the carrier phase, retaining all the observation information.

[0114] In the processing of ionospheric parameters, the undifferenced and non-combined model has a relatively complex processing of ionospheric parameters. It is necessary to accurately model the influence of ionospheric delay on the pseudorange and carrier phase observations, and usually some empirical models or external ionospheric data are used to estimate the ionospheric delay. In high-precision positioning, the spatio-temporal variation characteristics of the ionosphere also need to be considered to perform more refined modeling and estimation of the ionospheric delay. While the ionosphere-free combination model directly eliminates the influence of ionospheric delay through the combination of observations, without the need for separate modeling and estimation of the ionospheric delay. This method can effectively avoid the influence of ionospheric delay on the positioning result and improve the stability and accuracy of positioning in the case of strong ionospheric activity and large changes in ionospheric delay.

[0115] Therefore, in the positioning method provided in the embodiments of the present application, based on the ionospheric uncertainty information, it is determined whether the ionosphere is active (that is, the ionospheric activity is strong and the ionospheric delay changes greatly), and a model adapted to the current ionospheric conditions is selected from the non-differential non-combination model and the ionosphere-free combination model to position the user equipment. Specifically, in the case of weak ionospheric activity, the non-differential non-combination model is adopted to make full use of the information of the original observations to obtain higher positioning accuracy; while in the case of strong ionospheric activity, the ionosphere-free combination model is switched to ensure the stability and reliability of positioning. This method realizes the complementarity of the two models, thereby improving the positioning accuracy of the user equipment.

[0116] Correspondingly, an ionosphere adaptive enhanced positioning device is provided in the embodiments of the present application. The user equipment is positioned through a global satellite navigation system. The global satellite navigation system includes a ground end and a space end. The ground end includes a plurality of ground monitoring stations and a data center, and the space end includes a plurality of navigation satellites. As Figure 5 shown, it includes a first determination module 501, a second determination module 502, a third determination module 503, and a positioning module 504.

[0117] Among them, the first determination module 501 is used for the data center to determine the ionospheric delay information of each ground monitoring station among 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 navigation satellite among the plurality of navigation satellites. For example, the first determination module 501 is used to implement S103 of the above positioning method.

[0118] The second determination module 502 is used for the data center to 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 for each ground monitoring station among the plurality of ground monitoring stations; the ionospheric delay correction information includes the ionospheric delay correction data between the ground monitoring station and each navigation satellite among the plurality of navigation satellites. For example, the second determination module 502 is used to implement S104 of the above positioning method.

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

[0120] The positioning module 504 is used for the data center to broadcast the ionospheric uncertainty information of each navigation satellite among the plurality of navigation satellites for the positioning of the user equipment. Among them, 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 according to the judgment result.

[0121] Each module of the above positioning device can also be used to execute other steps in the above method embodiments. All relevant contents involved in the above method embodiments can be cited in the function descriptions of the corresponding functional modules, and will not be elaborated here.

[0122] The embodiment of the present application also provides an electronic device, including: a processor and a memory coupled to the processor; the memory is used to store computer instructions. When the electronic device runs, the processor executes the computer instructions stored in the memory so that the electronic device executes the method in the above embodiments. Among them, the processor can implement the above first determination module 501, second determination module 502, third determination module 503, and positioning module 504; the above memory can also be used to store ionospheric delay information, ionospheric delay correction information, ionospheric uncertainty information, etc.

[0123] The embodiment of the present application also provides a computer-readable storage medium, which includes a computer program. When the computer program runs on a computer, it executes the method described in the above embodiments.

[0124] The embodiment of the present application also provides a computer program product, which includes computer program instructions. When the computer program instructions run on a computer, they execute the method described in the above embodiments.

[0125] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and each embodiment focuses on 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, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the present application.

Claims

1. An ionospheric adaptive enhanced positioning method, characterized in that: Positioning a user equipment by a global satellite navigation system, the global satellite navigation system comprising a ground end and a space end, the ground end comprising a plurality of ground monitoring stations and a data center, the space end comprising a plurality of navigation satellites; the method comprising: The data center determines ionospheric delay information of each of the plurality of ground monitoring stations based on an ambiguity fixing method; the ionospheric delay information comprises 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 ionospheric delay correction information of the ground monitoring station based on ionospheric tilt delay information of the plurality of ground monitoring stations and an inverse range 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 plurality of navigation satellites; The data center determines ionospheric uncertainty information of each of the plurality of navigation satellites based on a cross-validation method and ionospheric delay correction information of each of the plurality of ground monitoring stations; The data center broadcasts the ionospheric uncertainty information of each navigation satellite among the multiple navigation satellites for positioning 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 according to claim 1, characterized in that 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 an inverse range linear interpolation method, including: For each ground monitoring station in the plurality of ground monitoring stations: The ground monitoring station is used as a central site, and multiple station networks are constructed according to multiple average distances; wherein each of the multiple station networks includes multiple ground monitoring stations centered on the central site; each of the station networks corresponds to an average distance, and the average distance is the average value of the distances between the multiple ground monitoring stations in the station network and the central site; The ionospheric delay information of the multiple ground monitoring stations of each of the multiple station networks is interpolated by using an inverse distance linear interpolation method to obtain the ionospheric delay correction information of the central site; the ionospheric delay correction information of the central site satisfies the following formula; Wherein, s represents the number of the navigation satellite, j represents the number of the station network, and u represents the central station. 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, represents the i-th ground monitoring station in the station network, represents the ionospheric delay information of the i-th ground monitoring station in the station network; w express The weight of represents the distance between the i-th ground monitoring station in the station network and the central station; Ionospheric delay correction information of each ground monitoring station in the plurality of ground monitoring stations is obtained.

3. The method according to claim 1 or 2, characterized in that For each navigation satellite in the plurality of navigation satellites, the ionospheric uncertainty information of the navigation satellite comprises ionospheric uncertainty information between each ground monitoring station in the plurality of 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; Where s represents the number of the navigation satellite, I represents the number of the ground monitoring station, represents the ionospheric uncertainty information between the navigation satellite and the ground monitoring station, and a0 and a1 satisfy the following formula; Where, s represents the number of the navigation satellite; Represents 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; 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 with the ground monitoring station as the central station; represents the ionospheric uncertainty information between the ground monitoring station and the navigation satellite numbered s in the pth station network corresponding to the ground monitoring station; d1 represents the average distance of the first station network; d j represents the average distance of the j-th station network; d p represents the average distance of the p-th station network; Satisfy the following formula; Wherein, n represents the total number of epochs required to determine the ionospheric delay information of the ground monitoring station; (u) represents the ionospheric tilt delay data between the ground monitoring station and the navigation satellite numbered s.

4. The method according to claim 1, characterized in that The method for positioning the user equipment is an ionosphere-free combined model or a non-difference non-combined model.

5. The method according to claim 1, characterized in that The method further comprises: For each navigation satellite among the multiple navigation satellites, the user equipment receives the ionospheric uncertainty information of the navigation satellite sent by the data center, and determines a correction value of the ionospheric uncertainty information of the navigation satellite according to the altitude angle of the navigation satellite; the correction value satisfies the following formula: Where s represents the number of the navigation satellite, I represents the number of the ground monitoring station, and ele represents the altitude angle between the ground monitoring station and the navigation satellite. A correction value representing the ionospheric uncertainty information between the navigation satellite and the ground monitoring station; 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 is ambiguity fixed; When it is determined that the ambiguity of the ambiguity fixing method is fixed, the user equipment is positioned by using a non-difference non-combined model; When it is determined that the ambiguity of the ambiguity fixing method is not fixed, the user equipment determines whether the ionosphere is active by using the correction value of the ionosphere uncertainty information of each of the multiple navigation satellites; the method for determining whether the ionosphere is active is: when the value obtained by calculating the uncertainty function of the ionosphere correction number is greater than the uncertainty threshold, or the change rate of the total electron content of the ionosphere is greater than the change rate threshold, the ionosphere is determined to be active; otherwise, the ionosphere is determined to be inactive; When it is determined that the ionosphere is active, the user equipment adopts an ionosphere-free combined model for positioning; When it is determined that the ionosphere is inactive, the user equipment adopts a non-difference non-combined model for positioning.

6. The method according to claim 5, characterized in that The method for determining whether the fuzziness is fixed is a Ratio test method or a Chi-square statistic test method.

7. An ionospheric adaptive enhanced positioning device, characterized in that: Positioning the user equipment through a global satellite navigation system, the global satellite navigation system comprising a ground end and a space end, the ground end comprising a plurality of ground monitoring stations and a data center, the space end comprising a plurality of navigation satellites; the device comprising a first determination module, a second determination module, a third determination module and a positioning module; The first determination module is used for the data center to determine the ionospheric delay information of each of the multiple 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 multiple navigation satellites; The second determination module is used for, for each of the multiple ground monitoring stations, the data center determining 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 range 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 determination module is used for, the data center to determine the ionospheric uncertainty information of each of the multiple navigation satellites based on a cross-validation method and the ionospheric delay correction information of each of the multiple ground monitoring stations; The positioning module is used for the data center to broadcast the ionospheric uncertainty information of each navigation satellite among the multiple navigation satellites for positioning 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: It comprises 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, so that the electronic device executes the method as described in any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that: The method comprises computer program instructions, which, when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises computer program instructions, and when the computer program instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 6.

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