A positioning method and device based on a reliable ionosphere model, electronic equipment and storage medium

Abstract

The application discloses a positioning method and device based on a reliable ionosphere model, electronic equipment and a storage medium. The method comprises the following steps: acquiring a plurality of to-be-solved satellite observation values, a slant delay ionosphere model corresponding to each to-be-solved satellite observation value, a model accuracy of each slant delay ionosphere model, a regional vertical ionosphere delay model and a model accuracy of the regional vertical ionosphere delay model; repeatedly performing a to-be-solved satellite observation value screening operation until a preset condition is met, and obtaining screened to-be-solved satellite observation values; and performing positioning calculation according to the screened to-be-solved satellite observation values, and obtaining final user position information. Through implementation of the application, the positioning accuracy can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of GNSS satellite navigation and positioning technology, specifically to a positioning method, device, electronic device, and storage medium based on a reliable ionospheric model. Background Technology

[0002] In GNSS positioning, ionospheric delay error is a significant factor affecting accuracy and convergence time. Therefore, providing high-precision and reliable estimates of ionospheric delay error is crucial for improving positioning accuracy and reducing positioning time.

[0003] In existing technologies, ionospheric analysis centers or service organizations typically construct ionospheric mathematical models by collecting observational data from global or regional reference stations to correct delay errors in satellite signals traversing the ionosphere. These models include low-order polynomial ionospheric models and slant-delay ionospheric models. Low-order polynomial ionospheric models are commonly used for large-scale ionospheric delay error correction due to their computational simplicity, applicability to a wide range of areas, and long validity period. However, their accuracy is limited, making it difficult to accurately reflect the complex variations in electron density in the ionosphere, especially in high-precision positioning where errors are significant. Slant-delay ionospheric models directly calculate the ionospheric delay of satellite signals along their path, avoiding projection function errors and thus providing higher-precision delay correction within a smaller area. However, due to the influence of high-speed satellite motion, slant-delay models have a short validity period, requiring frequent updates, and network transmission delays or data loss further limit their application effectiveness. Summary of the Invention

[0004] This invention provides a positioning method, apparatus, electronic device, and storage medium based on a reliable ionospheric model. By implementing this invention, users can obtain an effective ionospheric model most of the time to correct ionospheric delay errors, thereby significantly improving positioning accuracy in GNSS positioning.

[0005] One embodiment of the present invention provides a localization method based on a reliable ionospheric model, comprising:

[0006] Obtain several satellite observations to be solved, the oblique delay ionospheric model corresponding to each satellite observation, the model accuracy of each oblique delay ionospheric model, the regional vertical ionospheric delay model, and the model accuracy of the regional vertical ionospheric delay model;

[0007] Repeat the filtering operation of the satellite observations to be solved until the preset conditions are met, and obtain the filtered satellite observations to be solved.

[0008] Based on the filtered satellite observations to be solved, the positioning calculation is performed to obtain the final user location information;

[0009] The satellite observation value screening operation includes:

[0010] Obtaining a current satellite observation value set to be solved;

[0011] For each satellite observation value in the satellite observation value set to be solved, determining a target ionospheric delay model according to the validity period state of the corresponding slant delay ionospheric model and the regional vertical ionospheric delay model, and calculating a slant ionospheric delay error reference value of the corresponding satellite observation value according to the target ionospheric delay model;

[0012] For each slant ionospheric delay error reference value, calculating the precision corresponding to the slant ionospheric delay error reference value according to the corresponding satellite observation value, the corresponding target ionospheric delay model, and the model precision thereof;

[0013] According to all satellite observation values to be solved, the slant ionospheric delay error reference value corresponding to each satellite observation value, and the precision thereof, performing positioning solution to obtain current user position information;

[0014] For each satellite observation value, calculating a residual corresponding to the satellite observation value according to the current user position information;

[0015] For each satellite observation value, according to the corresponding residual, the corresponding slant ionospheric delay error reference value, and the precision thereof, eliminating the satellite observation value with gross error from the current satellite observation value set to be solved to obtain an updated satellite observation value set to be solved;

[0016] The preset condition is that there is no satellite observation value with gross error in the satellite observation value set to be solved or the satellite observation value set to be solved does not satisfy the condition for positioning solution.

[0017] Further, the slant delay ionospheric model corresponding to each satellite observation value to be solved and the model precision of each slant delay ionospheric model are provided by a server, and the server generates the slant delay ionospheric model corresponding to a satellite and the model precision of the slant delay ionospheric model in the following manner:

[0018] Obtaining a plurality of satellite observation values from a satellite, geographical position information of each reference station, pseudo-range hardware delay of each reference station, and pseudo-range hardware delay of the satellite;

[0019] For each satellite observation value, calculating a corresponding ionospheric delay observation value according to the pseudo-range hardware delay of the corresponding reference station and the pseudo-range hardware delay of the satellite;

[0020] For each satellite observation value, calculating a corresponding piercing point position using the ionospheric single-layer shell assumption according to the geographical position information of the corresponding reference station;

[0021] averaging the piercing point positions to generate a center coordinate of the satellite observation value;

[0022] fitting, according to the center coordinate of the satellite observation value, the piercing point position corresponding to each satellite observation value and the ionospheric delay observation value corresponding to each satellite observation value, a slant delay ionospheric model of the satellite through a least square method;

[0023] calculating, according to the ionospheric delay observation value corresponding to each satellite observation value, a residual statistical value of the slant delay ionospheric model as a model precision of the slant delay ionospheric model.

[0024] Further, the regional vertical ionospheric delay model and the model precision of the regional vertical ionospheric delay model are provided by a server, and the server generates the regional vertical ionospheric delay model and the model precision of the regional vertical ionospheric delay model through the following way:

[0025] obtaining a plurality of satellite observation values, geographical position information of each reference station, pseudo-range hardware delay of each reference station and pseudo-range hardware delay of each satellite;

[0026] for each satellite observation value, calculating a corresponding ionospheric delay observation value according to the pseudo-range hardware delay of the corresponding reference station and the pseudo-range hardware delay of the satellite;

[0027] for each satellite observation value, calculating a corresponding piercing point position according to the geographical position information of the corresponding reference station by using an ionospheric single-layer shell assumption;

[0028] averaging the geographical position information of each reference station to generate a center coordinate of the reference station;

[0029] fitting, according to the piercing point position corresponding to each satellite observation value, the center coordinate of the reference station and the ionospheric delay observation value corresponding to each satellite observation value, a vertical ionospheric delay model through a least square method;

[0030] calculating, according to the ionospheric delay observation value corresponding to each satellite observation value, a residual statistical value of the vertical ionospheric delay model as a model precision of the vertical ionospheric delay model.

[0031] Further, the corresponding piercing point position is calculated through the following formula:

[0032]

[0033] wherein, is a zenith distance of the satellite at the reference station, is a satellite azimuth, is a satellite elevation angle, is an earth radius, the height of the puncture point, and the latitude and longitude of the reference station, and the latitude and longitude of the puncture point.

[0034] Further, in the case of only one satellite observation value, the target ionospheric delay model is determined according to the validity state of the corresponding slant ionospheric delay model and the regional vertical ionospheric delay model; the slant ionospheric delay error reference value of the corresponding satellite observation value is calculated according to the target ionospheric delay model, comprising:

[0035] The judgment step: judging whether there is a usable ionospheric delay model at this time, if yes, judging whether the slant ionospheric delay model corresponding to the satellite observation value is within the validity period; if not, using the ionospheric delay model broadcast with the broadcast ephemeris to calculate the slant ionospheric delay value of the satellite observation value for position initialization, and re-executing the judgment step;

[0036] In the case that the slant ionospheric delay model corresponding to the satellite observation value is within the validity period, the slant ionospheric delay error reference value of the satellite observation value is calculated using the slant ionospheric delay model;

[0037] In the case that the slant ionospheric delay model corresponding to the satellite observation value is not within the validity period, it is checked whether the regional vertical ionospheric delay model is valid, if yes, the slant ionospheric delay error reference value of the satellite observation value is calculated using the vertical ionospheric delay model; if not, the slant ionospheric delay error reference value of the satellite observation value is calculated using the ionospheric delay model broadcast with the broadcast ephemeris.

[0038] Further, the accuracy corresponding to the slant ionospheric delay error reference value is calculated according to the corresponding satellite observation value, the corresponding target ionospheric delay model and the model accuracy thereof, comprising:

[0039] In the case that the corresponding target ionospheric delay model is a slant ionospheric delay model, the accuracy corresponding to the slant ionospheric delay error reference value is calculated by the following formula:

[0040]

[0041] wherein, the accuracy corresponding to the slant ionospheric delay error reference value; the model accuracy of the slant ionospheric delay model; the model accuracy time loss weight, the current calculation epoch, the generation time of the slant ionospheric delay model, the elevation angle of the corresponding satellite, a model precision height angle loss weight;

[0042] In the case that the corresponding target ionospheric delay model is a regional vertical ionospheric delay model, the precision corresponding to the slant ionospheric delay error reference value is calculated by the following formula:

[0043]

[0044] wherein, is the precision corresponding to the slant ionospheric delay error reference value, is a model precision of the vertical ionospheric delay model, is a projection function value corresponding to the satellite observation value, is a current calculation epoch, is a generation time of the slant ionospheric delay model;

[0045] In the case that the corresponding target ionospheric delay model is an ionospheric delay model broadcast with broadcast ephemeris, a preset precision is taken as the precision corresponding to the slant ionospheric delay error reference value.

[0046] Further, the satellite observation value with gross error is removed from the current set of satellite observation values to be calculated, to obtain an updated set of satellite observation values to be calculated, according to the corresponding residual, the corresponding slant ionospheric delay error reference value and the precision thereof, including:

[0047] The corresponding residual is subtracted from the slant ionospheric delay error reference value to obtain a difference result;

[0048] The difference result is taken as an absolute value to obtain an error result;

[0049] According to the error result and the precision corresponding to the slant ionospheric delay error reference value, it is determined whether the satellite observation value has gross error, and if the satellite observation value has gross error, the satellite observation value is removed from the current set of satellite observation values to be calculated, to obtain an updated set of satellite observation values to be calculated.

[0050] On the basis of the above method embodiment, the application provides a device embodiment.

[0051] An embodiment of the application provides a positioning device based on a reliable ionospheric model, which comprises a data and model acquisition module, a satellite observation value screening module, a positioning calculation module and a satellite observation value to be calculated screening module.

[0052] The data and model obtaining module is configured to obtain a plurality of satellite observation values to be solved, a slant delay ionospheric model corresponding to each satellite observation value to be solved, a model precision of each slant delay ionospheric model, a regional vertical ionospheric delay model, and a model precision of the regional vertical ionospheric delay model.

[0053] The satellite observation value screening module is configured to repeatedly execute the satellite observation value screening module until a preset condition is met, so as to obtain screened satellite observation values to be solved.

[0054] The positioning solution module is configured to perform positioning solution according to the screened satellite observation values to be solved, so as to obtain final user position information.

[0055] The satellite observation value screening module is configured to obtain a current satellite observation value set to be solved, determine a target ionospheric delay model according to a validity period state of the corresponding slant delay ionospheric model and the regional vertical ionospheric delay model for each satellite observation value in the satellite observation value set to be solved, calculate a slant ionospheric delay error reference value of the corresponding satellite observation value according to the target ionospheric delay model, calculate a precision corresponding to the slant ionospheric delay error reference value according to the corresponding satellite observation value, the corresponding target ionospheric delay model and the model precision thereof for each slant ionospheric delay error reference value, perform positioning solution according to all the satellite observation values to be solved, the slant ionospheric delay error reference value corresponding to each satellite observation value and the precision thereof, so as to obtain current user position information, calculate a residual error corresponding to the satellite observation value according to the current user position information for each satellite observation value, and remove the satellite observation value with gross error from the current satellite observation value set to be solved according to the corresponding residual error, the corresponding slant ionospheric delay error reference value and the precision thereof for each satellite observation value, so as to obtain an updated satellite observation value set to be solved.

[0056] On the basis of the above-mentioned method embodiment, the present application correspondingly provides an electronic device embodiment.

[0057] An embodiment of the present application provides an electronic device, which comprises a memory, a processor, and a computer program stored in the memory and capable of running on the processor, and the processor can implement the positioning method based on reliable ionospheric model in any of the above-mentioned method embodiments when executing the computer program.

[0058] On the basis of the above-mentioned method embodiment, the present application correspondingly provides a storage medium embodiment.

[0059] An embodiment of the present application provides a storage medium, which stores a computer program, and the computer program can implement the positioning method based on reliable ionospheric model in any of the above-mentioned method embodiments when executed by a processor.

[0060] Compared with the prior art, the present application has the following beneficial effects:

[0061] The embodiment of the present application provides a positioning method and device based on a reliable ionospheric model, electronic equipment and a storage medium. The method selects a suitable model to calculate a slant ionospheric delay error reference value according to the validity period state of the ionospheric model for each satellite observation value in a set of satellite observation values to be solved, and calculates the accuracy of the corresponding slant ionospheric delay error reference value based on the satellite observation value and the model accuracy. The current user position information is obtained by performing precise point positioning calculation on the satellite observation value, the slant ionospheric delay error reference value and the corresponding accuracy. Then, the residual error is calculated according to the position information, the delay error reference value and the accuracy, and the satellite observation value with gross error is eliminated. After eliminating the satellite observation value with gross error, the remaining effective observation value is used for precise point positioning calculation to obtain the final user position information.

[0062] The present application effectively combines the long validity period, flexible form of the low-order polynomial ionospheric model and the short validity period, high accuracy of the slant delay ionospheric model by simultaneously broadcasting the regional vertical ionospheric delay model and the slant delay ionospheric model belonging to the low-order polynomial ionospheric model to the user equipment for positioning. Through the method of the present application, the user can obtain effective ionospheric model at any time to correct ionospheric delay error, thereby significantly improving the positioning accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 is a flowchart of a positioning method based on a reliable ionospheric model provided by an embodiment of the present application.

[0064] Figure 2 is a flowchart of a satellite observation value screening operation provided by an embodiment of the present application.

[0065] Figure 3 is a flowchart of a positioning method based on a reliable ionospheric model provided by another embodiment of the present application.

[0066] Figure 4 is a structural diagram of a positioning device based on a reliable ionospheric model provided by an embodiment of the present application. DETAILED DESCRIPTION

[0067] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0068] As Figure 1 shown, an embodiment of the present application provides a positioning method based on a reliable ionospheric model, comprising at least the following steps:

[0069] Step S1, obtaining a plurality of satellite observation values to be solved, a slant delay ionospheric model corresponding to each satellite observation value to be solved, a model accuracy of each slant delay ionospheric model, a regional vertical ionospheric delay model, and a model accuracy of the regional vertical ionospheric delay model;

[0070] It should be noted that the generation process of the satellite observation value to be solved is that the user equipment of the user end receives the signal from the satellite, processes the signal to obtain the satellite observation value, and one satellite observation value corresponds to one satellite. The slant delay ionospheric model corresponding to each satellite observation value to be solved, the model accuracy of each slant delay ionospheric model, the regional vertical ionospheric delay model, and the model accuracy of the regional vertical ionospheric delay model are provided by the server.

[0071] In an optional embodiment, the server generates the slant delay ionospheric model corresponding to one satellite and the model accuracy of the slant delay ionospheric model in the following way:

[0072] Obtaining a plurality of satellite observation values from the satellite, geographical position information of each reference station, pseudorange hardware delay of each reference station, and pseudorange hardware delay of the satellite. Wherein, the reference station pseudorange hardware delay and the satellite pseudorange hardware delay are downloaded from the GNSS service agency or estimated by oneself.

[0073] For each satellite observation value, according to the pseudorange hardware delay of the corresponding reference station, the pseudorange hardware delay of the satellite, the corresponding ionospheric delay observation value is calculated and generated;

[0074] Specifically, the corresponding ionospheric delay observation value can be calculated and generated by the phase smoothing pseudorange method, and the specific steps include:

[0075] The GNSS observation equation is combined without geometry to generate the non-geometric observation value of the pseudorange and the carrier. Wherein, the GNSS observation equation is represented as:

[0076] (1)

[0077] Wherein, is the non-geometric combined pseudorange observation value; is the non-geometric combined carrier observation value, is the identification number of the reference station; is the identification number of the satellite, indicates the non-geometric combined carrier wavelength, denotes the slant total electron content (Slant TEC) on the GNSS signal path, and denotes the corresponding frequency of the two observations participating in the calculation, is the speed of light in vacuum, is the differential code bias of the receiver at the frequency and is the differential code bias of the satellite at the frequency and is the differential code bias of the satellite at the frequency is the carrier hardware delay of the receiver at the frequency is the carrier hardware delay of the satellite at the frequency is the carrier wavelength at the frequency is the carrier wavelength at the frequency is the carrier wavelength at the frequency is the carrier wavelength at the frequency is the ambiguity of the carrier observation in cycles. is the ambiguity of the carrier observation in cycles

[0078] is the carrier hardware delay of the receiver at the frequency and is the carrier hardware delay of the satellite at the frequency is constant and stable in the short time when no cycle slip occurs, so that, after the cycle slip is eliminated, the mean value of the short-time pseudorange and carrier geometry-free observations can be obtained as follows: (2)

[0079] (2)

[0080] wherein denotes the mean value of the sum of the pseudorange geometry-free combination observation and the carrier geometry-free combination observation in a continuous arc segment.

[0081] Solving equation (2) and equation (1) together, the phase-smoothed pseudorange observation corresponding to the satellite observation is generated:

[0082] (3)

[0083] wherein is the phase-smoothed pseudorange observation.

[0084] Solving equation (3) and equation (1) together, the ionospheric delay observation corresponding to the satellite observation is generated according to the pseudorange hardware delay of the reference station and the pseudorange hardware delay of the satellite:

[0085] (4)

[0086] wherein is the ionospheric delay observation.​​

[0087] Optionally, the corresponding ionospheric delay observation value can also be calculated by a non-difference non-combination PPP method.

[0088] For each satellite observation value, according to the geographical position information of the corresponding reference station, the corresponding piercing point position is calculated by using the ionospheric single-layer shell assumption.

[0089] In actual operation, the corresponding piercing point position is calculated by the following formula:

[0090] (5)

[0091] (6)

[0092] (7)

[0093] (8)

[0094] wherein, is the zenith distance of the satellite at the reference station, is the satellite azimuth, is the satellite elevation angle, is the earth radius, is the piercing point height, and is the latitude and longitude of the reference station, and is the latitude and longitude of the piercing point. Wherein, the satellite azimuth and the satellite elevation angle are calculated by the satellite position and the reference station position.

[0095] The piercing point position is averaged to generate the observation value center coordinates of the satellite;

[0096] In specific implementation, the observation value center coordinates of the satellite are generated by the following formula:

[0097] (9)

[0098] (10)

[0099] wherein, is the total number of epochs in the period to be modeled, is the number of reference stations participating in modeling, is the piercing point latitude of the observation value of the satellite by the reference station at the epoch is the piercing point latitude of the observation value of the satellite by the reference station at the epoch is the piercing point latitude of the observation value of the satellite by the reference station at the epoch is the piercing point latitude of the observation value of the satellite by the reference station at the epoch is the piercing point latitude of the observation value of the satellite by the reference station at the epoch is the piercing point latitude of the observation value of the satellite by the reference station at the epoch is the piercing point latitude of the observation value of the satellite by the reference station at the epoch the observation center coordinate of the observation value.

[0100] According to the observation center coordinate, the piercing point position corresponding to each satellite observation value, and the ionospheric delay observation value corresponding to each satellite observation value, a slant delay ionospheric model of the satellite is generated by least square fitting.

[0101] In a preferred embodiment, the slant delay ionospheric model of the satellite is generated by:

[0102] According to the observation center coordinate, the piercing point position corresponding to each satellite observation value, and the ionospheric delay observation value corresponding to each satellite observation value, a slant delay ionospheric model of the satellite is generated by least square fitting.

[0103] (11)

[0104] wherein, is the maximum order of the latitude difference direction; is the maximum order of the longitude difference direction, is the model coefficient, is the latitude difference of the piercing point to the observation center coordinate ; is the longitude difference of the piercing point to the observation center coordinate ;

[0105] The polynomial fitting is calculated by least square method:

[0106] (12)

[0107] (13)

[0108] (14)

[0109] wherein, is the polynomial coefficient to be solved, is the design matrix, each row of the matrix represents the model parameters corresponding to the satellite observation value at the time of the epoch ; is the ionospheric delay observation value corresponding to the satellite observation value, is the transpose of the matrix. According to the ionospheric delay observation value corresponding to each satellite observation value, the residual statistical value of the slant delay ionospheric model is calculated as the model accuracy of the slant delay ionospheric model.

[0110]

[0111] ​In actual calculation, the residual statistical value of the slant delay ionospheric model is calculated by the following formula:

[0112] (15)

[0113] (16)

[0114] (17)

[0115] wherein, the residual statistical value of the slant delay ionospheric model is taken as

[0116] In another optional embodiment, the regional vertical ionospheric delay model and the model accuracy of the regional vertical ionospheric delay model are provided by a server, and the server generates the regional vertical ionospheric delay model and the model accuracy of the regional vertical ionospheric delay model by the following manner:

[0117] Obtaining a plurality of satellite observation values, geographical position information of each reference station, pseudo-range hardware delay of each reference station and pseudo-range hardware delay of each satellite;

[0118] For each satellite observation value, according to the pseudo-range hardware delay of the corresponding reference station and the pseudo-range hardware delay of the satellite, a corresponding ionospheric delay observation value is calculated and generated;

[0119] For each satellite observation value, according to the geographical position information of the corresponding reference station, the position of the corresponding piercing point is calculated and generated by using the ionospheric single-layer shell assumption;

[0120] The geographical position information of each reference station is subjected to an averaging operation to generate the central coordinates of the reference station;

[0121] According to the position of the corresponding piercing point of each satellite observation value, the central coordinates of the reference station and the ionospheric delay observation value corresponding to each satellite observation value, a vertical ionospheric delay model is generated by least square fitting;

[0122] In an embodiment, the vertical ionospheric delay model is generated by the following manner:

[0123] According to the projection function, the ionospheric delay observation value corresponding to each satellite observation value is converted to obtain a converted ionospheric delay observation value, and the specific calculation process is as follows:

[0124] (18)

[0125] wherein, is the projection function; is the converted ionospheric delay observation value; is obtained by the following formula:​

[0126] (19)

[0127] According to the piercing point position corresponding to each satellite observation value, the center coordinates of the reference station and the ionospheric delay observation value corresponding to each satellite observation value, the satellite observation value is fitted by using a polynomial model to obtain a satellite slant delay ionospheric model:

[0128] (20)

[0129] The latitude difference of the piercing point to the center coordinates of the reference station ; The longitude difference of the piercing point to the observation value center coordinates ;

[0130] The polynomial fitting is calculated by the least square method:

[0131] (21)

[0132] (22)

[0133] (23)

[0134] Wherein, in the formula is the polynomial coefficient to be solved, is the design matrix, each row in the matrix represents the model parameters corresponding to the satellite observation value of a reference station at the time of epoch , represents the ionospheric delay observation value of the reference station to the satellite at the time of , all satellite observation values of all reference stations in the modeling period are contained in , is the ionospheric delay observation value, is the transpose of the matrix. According to the ionospheric delay observation value corresponding to each satellite observation value, the residual statistical value of the vertical ionospheric delay model is calculated as the model accuracy of the vertical ionospheric delay model.

[0135]

[0136] ​Preferably, the server encodes the generated slant ionospheric delay model, the model accuracy of the slant ionospheric delay model, the regional vertical ionospheric delay model and the model accuracy of the regional vertical ionospheric delay model using the RTCM standard and broadcasts them to the user terminal for positioning by the user terminal.

[0137] Step S2, repeatedly performing the satellite observation value screening operation until a preset condition is met, to obtain screened satellite observation values to be solved;

[0138] As shown in Figure 2 in a preferred embodiment, the satellite observation value screening operation includes:

[0139] Step S2.1, obtaining a current satellite observation value set to be solved.

[0140] It should be noted that the current satellite observation value set to be solved at the initial moment contains the satellite observation values to be solved obtained in step S1.

[0141] Step S2.2, for each satellite observation value in the satellite observation value set to be solved, determining a target ionospheric delay model according to the validity state of the corresponding slant ionospheric delay model and regional vertical ionospheric delay model; calculating the slant ionospheric delay error reference value of the corresponding satellite observation value according to the target ionospheric delay model.

[0142] In a preferred embodiment, in the case of only one satellite observation value, the determination of the target ionospheric delay model according to the validity state of the corresponding slant ionospheric delay model and regional vertical ionospheric delay model; calculating the slant ionospheric delay error reference value of the corresponding satellite observation value according to the target ionospheric delay model includes:

[0143] Judgment step: judging whether there is a usable ionospheric delay model at this time, if so, judging whether the slant ionospheric delay model corresponding to the satellite observation value is within the validity period by the following formula:

[0144] (24)

[0145] wherein, is the current solution epoch, is the generation time of the slant ionospheric delay model corresponding to the satellite observation value, is the validity period of the slant ionospheric delay model corresponding to the satellite observation value.

[0146] If not, use the ionospheric delay model broadcast with the broadcast ephemeris to calculate the slant ionospheric delay value of the satellite observation value for position initialization, and re-execute the judgment step;

[0147] In the case that the slant ionospheric delay model corresponding to the satellite observation value is within the validity period, the slant ionospheric delay error reference value of the satellite observation value is calculated using the slant ionospheric delay model;

[0148] In the case that the slant ionospheric delay model corresponding to the satellite observation value is not within the validity period, it is checked whether the regional vertical ionospheric delay model is valid, the validity period checking method is shown in formula 24; if valid, the slant ionospheric delay error reference value of the satellite observation value is calculated using the vertical ionospheric delay model; if invalid, the slant ionospheric delay error reference value of the satellite observation value is calculated using the ionospheric delay model broadcast with the broadcast ephemeris.

[0149] Step S2.3, for each slant ionospheric delay error reference value, the accuracy corresponding to the slant ionospheric delay error reference value is calculated according to the corresponding satellite observation value, the corresponding target ionospheric delay model and the model accuracy thereof.

[0150] In actual operation, the accuracy corresponding to the slant ionospheric delay error reference value is calculated according to the corresponding satellite observation value, the corresponding target ionospheric delay model and the model accuracy thereof, including:

[0151] In the case that the corresponding target ionospheric delay model is a slant ionospheric delay model, the accuracy corresponding to the slant ionospheric delay error reference value is calculated by the following formula:

[0152] (25)

[0153] Wherein, is the accuracy corresponding to the slant ionospheric delay error reference value; is the model accuracy of the slant ionospheric delay model; is the model accuracy time loss weight, is the current calculation epoch, is the generation time of the slant ionospheric delay model, is the elevation angle of the corresponding satellite, is the model accuracy elevation angle loss weight;

[0154] In the case that the corresponding target ionospheric delay model is a regional vertical ionospheric delay model, the accuracy corresponding to the slant ionospheric delay error reference value is calculated by the following formula:

[0155] (26)

[0156] Wherein, is the accuracy corresponding to the slant ionospheric delay error reference value, is the model accuracy of the vertical ionospheric delay model, is the projection function value of the corresponding satellite observation value, is the time of the current epoch, is the time of generating the slant ionospheric delay model;

[0157] In the case that the corresponding target ionospheric delay model is an ionospheric delay model broadcasted with a broadcast ephemeris, the preset accuracy is the accuracy corresponding to the slant ionospheric delay error reference value. The preset accuracy may be set by the user as needed.

[0158] Step S2.4, according to all the satellite observation values to be solved, the slant ionospheric delay error reference value corresponding to each satellite observation value and the accuracy thereof, positioning is solved to obtain the current user position information.

[0159] Step S2.5, for each satellite observation value, the residual corresponding to the satellite observation value is calculated according to the current user position information.

[0160] Optionally, the residual corresponding to the satellite observation value is calculated by the following method:

[0161] The current user position information and other solving parameters (such as receiver clock error, tropospheric delay, ambiguity estimate value, etc.) except the slant ionospheric delay error reference value parameter are substituted into the solving equation. The solving equation is as follows:

[0162] (27)

[0163] wherein, is an expectation operator, is a reference station identifier, is a satellite identifier, is an epoch time, is the pseudorange observation value from the reference station to the satellite at the epoch time, is the carrier observation value from the reference station to the satellite at the epoch time, is the carrier wavelength of the satellite first frequency point observation value, is the satellite-geodetic distance from the reference station to the satellite at the epoch time, is the receiver clock error at the epoch time, is the satellite clock error at the epoch time, is the base station clock error at the epoch time tropospheric delay, time reference station to satellite ionospheric delay, frequency of the observation value of the first frequency, time reference station carrier hardware delay of the first frequency, time satellite carrier hardware delay of the first frequency, carrier ambiguity of the observation value of the first frequency.

[0164] The residual corresponding to the satellite observation value is obtained by subtracting the calculated parameters (such as receiver clock error, tropospheric delay, ambiguity estimate, etc.) on the right side of the above formula (formula 27) from the observation value on the left side of the equation;

[0165] Step S2.6, for each satellite observation value, according to the corresponding residual, the corresponding reference value of the slant ionospheric delay error and its corresponding accuracy, the satellite observation value with gross error is removed from the current set of satellite observation values to be calculated, and an updated set of satellite observation values to be calculated is obtained.

[0166] In an optional embodiment, the satellite observation value with gross error is removed from the current set of satellite observation values to be calculated according to the corresponding residual, the corresponding reference value of the slant ionospheric delay error and its corresponding accuracy, and an updated set of satellite observation values to be calculated is obtained, comprising:

[0167] The residual corresponding to the satellite observation value, the corresponding reference value of the slant ionospheric delay error and its corresponding accuracy are compared by the following formula:

[0168] (28)

[0169] wherein, is the residual corresponding to the satellite observation value, is the reference value of the slant ionospheric delay error corresponding to the satellite observation value, is the accuracy of the reference value of the slant ionospheric delay error corresponding to the satellite observation value (* indicates different calculation results according to different models, that is, the corresponding accuracy is selected according to the selected model), and is taken as the threshold value of whether there is a gross error.

[0170] ​​​​​​​​If the residual corresponding to the satellite observation value exceeds the threshold value, it is considered that the satellite observation value has gross error, and the satellite observation value is removed from the current satellite observation value set to be solved, and an updated satellite observation value set to be solved is obtained.

[0171] Step S3, according to the screened satellite observation value to be solved, positioning calculation is carried out, and the final user position information is obtained.

[0172] In a preferred embodiment, the step S2.2 uses the ionospheric delay model broadcast with the broadcast ephemeris to calculate the slant ionospheric delay value of the satellite observation value to perform position initialization, which includes:

[0173] According to the ionospheric delay model broadcast with the broadcast ephemeris and the satellite observation value to be solved in the current satellite observation value set to be solved, the positioning calculation is carried out, and when the position error is less than 100 meters, it is considered to be qualified, and then the position initialization is carried out.

[0174] In a preferred embodiment, the positioning method based on the reliable ionospheric model provided by the application provides a flowchart of the server and the user terminal as shown in Figure 3 The receiver DCB correction number and the satellite DCB correction number in the figure are used to calculate the pseudorange hardware delay of the reference station and the pseudorange hardware delay of the satellite.

[0175] On the basis of the above-mentioned method embodiment, the application correspondingly provides a device embodiment.

[0176] As shown in Figure 4 An embodiment of the application provides a positioning device based on a reliable ionospheric model, which comprises a data and model acquisition module 101, a satellite observation value screening module 102, a satellite observation value to be solved screening module 103 and a positioning calculation module 104.

[0177] The data and model acquisition module 101 is used to acquire a plurality of satellite observation values to be solved, a slant delay ionospheric model corresponding to each satellite observation value to be solved, a model accuracy of each slant delay ionospheric model, a regional vertical ionospheric delay model and a model accuracy of the regional vertical ionospheric delay model.

[0178] The satellite observation value screening module 102 is used to repeatedly execute the satellite observation value to be solved screening module until a preset condition is met, and the screened satellite observation value to be solved is obtained.

[0179] The satellite observation value to be solved filtering module 103 is configured to acquire a current satellite observation value set to be solved; for each satellite observation value in the satellite observation value set to be solved, determine a target ionospheric delay model according to the validity period state of the corresponding slant ionospheric delay model and the regional vertical ionospheric delay model; calculate a slant ionospheric delay error reference value of the corresponding satellite observation value according to the target ionospheric delay model; for each slant ionospheric delay error reference value, calculate the precision corresponding to the slant ionospheric delay error reference value according to the corresponding satellite observation value, the corresponding target ionospheric delay model and the model precision thereof; perform positioning calculation according to all the satellite observation values to be solved, the slant ionospheric delay error reference value corresponding to each satellite observation value and the precision thereof, to obtain current user position information; for each satellite observation value, calculate a residual error corresponding to the satellite observation value according to the current user position information; for each satellite observation value, according to the corresponding residual error, the corresponding slant ionospheric delay error reference value and the precision thereof, eliminate the satellite observation value with gross errors from the current satellite observation value set to be solved, to obtain an updated satellite observation value set to be solved.

[0180] The positioning calculation module 104 is configured to perform positioning calculation according to the filtered satellite observation value to be solved, to obtain final user position information.

[0181] It should be noted that the above-described device embodiments correspond to the above-mentioned embodiments of the present application, and can realize any of the above-mentioned methods of the present application. In addition, the above-mentioned device embodiments are only illustrative, and the modules described as separate components can or can not be physically separated, and the components displayed as modules can or can not be physical units, i.e., they can be located in one place or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the present embodiment according to actual needs. In addition, in the device embodiment provided by the present application, the connection relationship between the modules indicates that there is a communication connection between them, which can be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement it without creative labor.

[0182] On the basis of the above-mentioned method embodiment of the present application, an electronic device embodiment is correspondingly provided.

[0183] An electronic device is provided in an embodiment of the present application, which comprises a processor, a memory and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the positioning method based on reliable ionospheric model according to any one of the embodiments of the present application is implemented, or when the processor executes the computer program, the functions of the modules in the above-mentioned device embodiments are implemented.

[0184] For example, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present application. The one or more modules can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the terminal device.

[0185] The terminal device can be a desktop computer, a notebook computer, a palm computer, a cloud server and the like. The terminal device can include, but is not limited to, a processor and a memory.

[0186] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The processor is the control center of the terminal device, and connects all parts of the terminal device through various interfaces and lines.

[0187] The memory can be used to store the computer program and / or modules, and the processor realizes various functions of the terminal device by running or executing the computer program and / or modules stored in the memory, and calling data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required by a function, etc.; and the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory can include a high-speed random access memory, and can also include a nonvolatile memory, for example, a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state memory devices.

[0188] On the basis of the above-mentioned method embodiment, the present application correspondingly provides a storage medium embodiment;

[0189] Another embodiment of the present application provides a storage medium, comprising a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute any one of the positioning methods based on the reliable ionosphere model as described above.

[0190] The storage medium is a computer readable storage medium, the computer program comprises computer program code, and the computer program code can be in the form of source code, object code, an executable file, or some intermediate form, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content contained in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include an electrical carrier signal and a telecommunication signal.

[0191] In the description of the present specification, the description of the terms “one embodiment”, “some embodiments”, “an example”, “a specific example” or “some examples” means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0192] The above is the preferred embodiment of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements are also considered within the scope of protection of the present application.

Claims

1. A localization method based on a reliable ionospheric model, characterized in that, include: Obtain several satellite observations to be solved, the oblique delay ionospheric model corresponding to each satellite observation, the model accuracy of each oblique delay ionospheric model, the regional vertical ionospheric delay model, and the model accuracy of the regional vertical ionospheric delay model; Repeat the filtering operation of the satellite observations to be solved until the preset conditions are met, and obtain the filtered satellite observations to be solved. Based on the filtered satellite observations to be solved, the positioning calculation is performed to obtain the final user location information; The process of filtering satellite observations to be solved includes: Obtain the current set of satellite observations to be solved; For each satellite observation in the set of satellite observations to be solved, the target ionospheric delay model is determined based on the validity status of the corresponding oblique delay ionospheric model and the regional vertical ionospheric delay model; the oblique ionospheric delay error reference value of the corresponding satellite observation is calculated based on the target ionospheric delay model. For each oblique ionospheric delay error reference value, the accuracy corresponding to the oblique ionospheric delay error reference value is calculated based on the corresponding satellite observation value, the corresponding target ionospheric delay model and its model accuracy. Based on all satellite observations to be solved, the oblique ionospheric delay error reference value corresponding to each satellite observation and its corresponding accuracy, the positioning solution is performed to obtain the current user location information; For each satellite observation, the residual corresponding to the satellite observation is calculated based on the current user location information; For each satellite observation, based on the corresponding residual, the corresponding oblique ionospheric delay error reference value and its corresponding accuracy, satellite observations with gross errors are removed from the current set of satellite observations to be solved, resulting in an updated set of satellite observations to be solved. The preset condition is that there are no gross errors in the satellite observation set to be solved, or the satellite observation set to be solved does not meet the conditions for positioning solution.

2. The localization method based on a reliable ionospheric model as described in claim 1, characterized in that, The oblique delay ionospheric model corresponding to each satellite observation to be solved, and the model accuracy of each oblique delay ionospheric model, are provided by the server. The server generates the oblique delay ionospheric model and the model accuracy of the oblique delay ionospheric model corresponding to a satellite in the following way: Acquire several satellite observations from the satellite, the geographical location information of each reference station, the pseudorange hardware delay of each reference station, and the pseudorange hardware delay of the satellite. For each satellite observation, the corresponding ionospheric delay observation is calculated and generated based on the pseudorange hardware delay of the corresponding reference station and the pseudorange hardware delay of the satellite. For each satellite observation, the location of the corresponding puncture point is calculated using the ionospheric single-layer thin shell assumption, based on the geographical location information of the corresponding reference station. The average value of the puncture point locations is used to generate the center coordinates of the satellite observation values; Based on the center coordinates of the observations, the puncture point location corresponding to each satellite observation, and the ionospheric delay observation corresponding to each satellite observation, a satellite oblique delay ionospheric model is generated by fitting using the least squares method. Based on the ionospheric delay observation value corresponding to each satellite observation value, the residual statistics of the oblique delay ionospheric model are calculated as the model accuracy of the oblique delay ionospheric model.

3. The localization method based on a reliable ionospheric model as described in claim 1, characterized in that, The regional vertical ionospheric delay model and its accuracy are provided by the server. The server generates the regional vertical ionospheric delay model and its accuracy in the following way: Acquire several satellite observations, the geographical location information of each reference station, the pseudorange hardware delay of each reference station, and the pseudorange hardware delay of each satellite. For each satellite observation, the corresponding ionospheric delay observation is calculated and generated based on the pseudorange hardware delay of the corresponding reference station and the pseudorange hardware delay of the satellite. For each satellite observation, the location of the corresponding puncture point is calculated using the ionospheric single-layer thin shell assumption, based on the geographical location information of the corresponding reference station. The average value of the geographical location information of each base station is used to generate the center coordinates of the base station; Based on the puncture point location corresponding to each satellite observation, the center coordinates of the reference station, and the ionospheric delay observation value corresponding to each satellite observation, a vertical ionospheric delay model is generated by fitting using the least squares method. Based on the ionospheric delay observation value corresponding to each satellite observation value, the residual statistics of the vertical ionospheric delay model are calculated as the model accuracy of the vertical ionospheric delay model.

4. The localization method based on a reliable ionospheric model as described in claim 3, characterized in that, The corresponding puncture point location is calculated using the following formula: in, The zenith distance of the satellite at the reference station. For satellite azimuth, For the satellite elevation angle, For the Earth's radius, The height of the puncture point. and For the latitude and longitude of the base station, and The latitude and longitude of the puncture point.

5. The localization method based on a reliable ionospheric model as described in claim 1, characterized in that, In the case of only one satellite observation, the target ionospheric delay model is determined based on the validity status of the corresponding oblique delay ionospheric model and the regional vertical ionospheric delay model. The oblique ionospheric delay error reference value for the corresponding satellite observations is calculated based on the target ionospheric delay model, including: Judgment steps: Determine if there is an available ionospheric delay model. If so, determine if the oblique ionospheric delay model corresponding to the satellite observation is within its validity period. If not, use the ionospheric delay model broadcast with the ephemeris to calculate the oblique ionospheric delay value of the satellite observation for position initialization, and re-execute the judgment steps. If the oblique ionospheric delay model corresponding to the satellite observations is within its validity period, the oblique ionospheric delay model is used to calculate the reference value of the oblique ionospheric delay error of the satellite observations. If the oblique ionospheric delay model corresponding to the satellite observations is not valid, check whether the regional vertical ionospheric delay model is valid. If valid, use the vertical ionospheric delay model to calculate the oblique ionospheric delay error reference value of the satellite observations; if invalid, use the ionospheric delay model broadcast with the broadcast ephemeris to calculate the oblique ionospheric delay error reference value of the satellite observations.

6. The localization method based on a reliable ionospheric model as described in claim 1, characterized in that, The step of calculating the accuracy corresponding to the oblique ionospheric delay error reference value based on the corresponding satellite observations, the corresponding target ionospheric delay model and its model accuracy includes: When the corresponding target ionospheric delay model is an oblique ionospheric delay model, the accuracy corresponding to the oblique ionospheric delay error reference value is calculated using the following formula: in, This refers to the accuracy corresponding to the reference value for oblique ionospheric delay error; To improve the model accuracy of the oblique ionospheric delay model; The time loss weights for model accuracy are used. For the current epoch of the solution, The generation time of the oblique ionospheric delay model. For the corresponding satellite elevation angle, The elevation angle loss is used as the model accuracy weight. When the corresponding target ionospheric delay model is a regional vertical ionospheric delay model, the accuracy corresponding to the oblique ionospheric delay error reference value is calculated using the following formula: in, This is the accuracy corresponding to the reference value of the oblique ionospheric delay error. To improve the model accuracy of the vertical ionospheric delay model, This represents the projection function value corresponding to the satellite observations. For the current epoch of the solution, This represents the generation time of the oblique ionospheric delayed model; When the corresponding target ionospheric delay model is an ionospheric delay model broadcast with ephemeris data, the preset accuracy will be used. The accuracy corresponding to the oblique ionospheric delay error reference value.

7. The localization method based on a reliable ionospheric model as described in claim 1, characterized in that, The process involves removing satellite observations with gross errors from the current set of satellite observations to be solved, based on the corresponding residuals, the corresponding oblique ionospheric delay error reference values, and their corresponding accuracy, to obtain an updated set of satellite observations to be solved, including: The difference is obtained by subtracting the corresponding residual from the oblique ionospheric delay error reference value. Take the absolute value of the difference to obtain the error result; Based on the error results and the corresponding accuracy of the oblique ionospheric delay error reference value, it is determined whether there are gross errors in the satellite observations. If there are gross errors in the satellite observations, the satellite observations are removed from the current set of satellite observations to be solved, and an updated set of satellite observations to be solved is obtained.

8. A positioning device based on a reliable ionospheric model, characterized in that, include: The system includes a data and model acquisition module, a satellite observation filtering module, a positioning and calculation module, and a satellite observation filtering module to be calculated. The data and model acquisition module is used to acquire several satellite observations to be solved, the oblique delay ionospheric model corresponding to each satellite observation, the model accuracy of each oblique delay ionospheric model, the regional vertical ionospheric delay model, and the model accuracy of the regional vertical ionospheric delay model. The satellite observation filtering module is used to repeatedly execute the satellite observation filtering module to be solved until the preset conditions are met, and obtain the filtered satellite observations to be solved. The positioning calculation module is used to perform positioning calculation based on the filtered satellite observation values ​​to obtain the final user location information; The satellite observation filtering module is used to obtain the current set of satellite observations to be solved; for each satellite observation in the set, the target ionospheric delay model is determined based on the validity status of the corresponding oblique delay ionospheric model and the regional vertical ionospheric delay model; the oblique ionospheric delay error reference value of the corresponding satellite observation is calculated based on the target ionospheric delay model; for each oblique ionospheric delay error reference value, the accuracy corresponding to the oblique ionospheric delay error reference value is calculated based on the corresponding satellite observation, the corresponding target ionospheric delay model and its model accuracy; positioning is calculated based on all satellite observations to be solved, the oblique ionospheric delay error reference value corresponding to each satellite observation and its corresponding accuracy to obtain the current user location information; for each satellite observation, the residual corresponding to the satellite observation is calculated based on the current user location information; for each satellite observation, satellite observations with gross errors are removed from the current set of satellite observations to be solved based on the corresponding residual, the corresponding oblique ionospheric delay error reference value and its corresponding accuracy to obtain an updated set of satellite observations to be solved.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it can implement the localization method based on a reliable ionospheric model as described in any one of claims 1 to 7.

10. A storage medium having a computer program stored thereon, characterized in that: When executed by a processor, the computer program can implement the localization method based on a reliable ionospheric model as described in any one of claims 1 to 7.

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