Ionized layer modeling method, device and equipment and storage medium

Abstract

The invention discloses an ionosphere modeling method, device and equipment and a storage medium, and the method comprises the steps: calculating ionosphere delay corresponding to historical GNSS observation data according to an ionosphere model corresponding to the historical GNSS observation data, and then separating the coupled ionosphere delay and differential code deviation information; the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information are separated; fitting to obtain a change rule of the receiver differential code deviation and the satellite differential code deviation, and estimating a receiver differential code deviation estimated value and a satellite differential code deviation estimated value in the to-be-modeled time period; and in the GNSS observation data in the to-be-modeled time period, removing the receiver differential code deviation estimated value and the satellite differential code deviation estimated value, and then constructing a corresponding ionosphere model in the to-be-modeled time period according to the removed GNSS observation data. According to the invention, the precision of the constructed ionosphere model can be improved.

Description

Technical Field

[0001] The present invention relates to the field of GNSS precision data processing technology, and in particular to an ionosphere modeling method, device, equipment and storage medium. Background Art

[0002] During GNSS positioning, the error caused by satellite signals passing through the ionosphere is an important factor restricting positioning accuracy and positioning convergence time. Therefore, an accurate ionosphere model can provide more accurate ionosphere initial values ​​and weights for the positioning solution filtering process, thereby improving the startup positioning accuracy and shortening the positioning convergence time.

[0003] The receiver differential code bias and satellite differential code bias are major factors that restrict the accuracy of the model in the ionosphere modeling process. Since the differential code bias is coupled with the ionospheric delay obtained from the GNSS observations, the differential code bias cannot be separated. Therefore, it is necessary to separate it from the total electron content of the ionosphere by assuming that the differential code bias is a constant within a short period of time (one day) during the modeling process. This assumption is based on the premise that the receiver state and the environment are stable. However, in the actual production process, due to the influence of factors such as the temperature and humidity of the receiver environment, the space radiation in the space environment where the satellite is located, and the service life of the receiver and satellite, the stability of the differential code bias cannot be guaranteed, which leads to the low accuracy of the constructed ionosphere model. Summary of the invention

[0004] The present invention provides an ionospheric modeling method, device, equipment and storage medium to solve the technical problem that the differential code deviation and the ionospheric delay obtained from the GNSS observation value are coupled with each other, and the differential code deviation cannot be separated, resulting in low accuracy of the constructed ionospheric model.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides an ionosphere modeling method, including:

[0006] Acquire a number of historical GNSS observation data of the area to be modeled within a preset time period; wherein the historical GNSS observation data includes: historical pseudorange observation data and historical carrier observation data of all base station receivers;

[0007] Calculate the coupled ionospheric delay and differential code bias information corresponding to each historical GNSS observation data; wherein the differential code bias information includes: receiver differential code bias and satellite differential code bias;

[0008] Calculating the ionospheric delay corresponding to the historical GNSS observation data according to the ionospheric model corresponding to the historical GNSS observation data, and then separating the coupled ionospheric delay and differential code deviation information;

[0009] According to the separated differential code deviation information, separating the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information;

[0010] According to the separated receiver differential code deviation, the variation law of the receiver differential code deviation is obtained by fitting, and according to the separated satellite differential code deviation, the variation law of the satellite differential code deviation is obtained by fitting;

[0011] According to the variation law of the receiver differential code deviation, the estimated value of the receiver differential code deviation in the period to be modeled is estimated; according to the variation law of the satellite differential code deviation, the estimated value of the satellite differential code deviation in the period to be modeled is estimated;

[0012] According to the receiver differential code bias estimate and the satellite differential code bias estimate, the receiver differential code bias estimate and the satellite differential code bias estimate are eliminated from the GNSS observation data within the period to be modeled, and then the corresponding ionospheric model within the period to be modeled is constructed based on the eliminated GNSS observation data.

[0013] As a preferred solution, the ionospheric modeling method further includes:

[0014] According to the constructed ionospheric model and the corresponding GNSS observation data, the ionospheric delay in the GNSS observation data is eliminated, and then GNSS positioning is performed based on the eliminated GNSS observation data.

[0015] As a preferred solution, the calculation of coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data includes:

[0016] According to the historical pseudorange observation data, a corresponding geometry-free combined pseudorange observation value is calculated, and according to the historical carrier observation data, a corresponding geometry-free combined carrier observation value is calculated;

[0017] The mean of the sum of the geometry-free combined pseudorange observation values ​​and the geometry-free combined carrier observation values ​​within the same preset arc segment is calculated, and then the coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data is calculated based on the mean and the geometry-free combined carrier observation values.

[0018] As a preferred solution, the coupled ionospheric delay and differential code deviation information is:

[0019]

[0020] in, represents the geometry-free combined carrier observation in meters, STEC represents the ionospheric delay, and f 1 represents the frequency corresponding to the pseudorange observation value without geometric combination, f2 represents the frequency corresponding to the carrier observation value without geometric combination, c represents the speed of light in vacuum, DCB r,1|2 Indicates that the receiver is at frequency f 1 and frequency f 2 The receiver differential code deviation on Indicates that the satellite is at frequency f 1 and f 2 The satellite differential code bias on It represents the mean of the sum of the geometry-free combined pseudorange observation values ​​and the geometry-free combined carrier observation values ​​within the same preset arc segment.

[0021] As a preferred solution, the ionospheric delay corresponding to the historical GNSS observation data is calculated according to the ionospheric model corresponding to the historical GNSS observation data, and then the coupled ionospheric delay and differential code deviation information are separated, including:

[0022] Determine whether there is a corresponding ionospheric model for the historical GNSS observation data; when it is determined that there is a corresponding ionospheric model for the historical GNSS observation data, calculate the puncture point coordinates of the historical GNSS observation data at the corresponding ionospheric model height according to the ionospheric model corresponding to the historical GNSS observation data;

[0023] Calculating the vertical path value corresponding to the historical GNSS observation data according to the puncture point coordinates;

[0024] Calculating an ionospheric projection function value corresponding to the historical GNSS observation data, and then converting the vertical path value into a corresponding inclined path value according to the ionospheric projection function value;

[0025] The tilt path value is used as the ionospheric delay corresponding to the historical GNSS observation data, and then the coupled ionospheric delay and differential code deviation information are separated.

[0026] As a preferred solution, the method of calculating the ionospheric delay corresponding to the historical GNSS observation data according to the ionospheric model corresponding to the historical GNSS observation data, and then separating the coupled ionospheric delay and differential code deviation information, further includes:

[0027] When it is determined that there is no corresponding ionospheric model for the historical GNSS observation data, it is assumed that the receiver differential code bias and the satellite differential code bias corresponding to the historical GNSS observation data are the same within a preset period of time, and then the ionospheric model corresponding to the historical GNSS observation data is solved according to the preset ionospheric model and the solution equation of the differential code bias;

[0028] According to the ionosphere model corresponding to the historical GNSS observation data, calculating the puncture point coordinates of the historical GNSS observation data at the corresponding ionosphere model height;

[0029] Calculating the vertical path value corresponding to the historical GNSS observation data according to the puncture point coordinates;

[0030] Calculating an ionospheric projection function value corresponding to the historical GNSS observation data, and then converting the vertical path value into a corresponding inclined path value according to the ionospheric projection function value;

[0031] The tilt path value is used as the ionospheric delay corresponding to the historical GNSS observation data, and then the coupled ionospheric delay and differential code deviation information are separated.

[0032] As a preferred solution, the method of separating the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information according to the separated differential code deviation information includes:

[0033] According to the separated differential code deviation information, the sum of the satellite differential code deviations in the differential code deviation information is set to zero, and the corresponding receiver differential code deviation is obtained by solving, and then the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information are separated.

[0034] On the basis of the above-mentioned embodiment, another embodiment of the present invention provides an ionosphere modeling device, comprising: a historical observation data acquisition module, a coupling data calculation module, a coupling data separation module, a differential code deviation information separation module, a change law fitting module, a differential code deviation estimation module and an ionosphere model construction module;

[0035] The historical observation data acquisition module is used to acquire a number of historical GNSS observation data of the area to be modeled within a preset time period; wherein the historical GNSS observation data includes: historical pseudo-range observation data and historical carrier observation data of all base station receivers;

[0036] The coupled data calculation module is used to calculate the coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data; wherein the differential code deviation information includes: receiver differential code deviation and satellite differential code deviation;

[0037] The coupled data separation module is used to calculate the ionospheric delay corresponding to the historical GNSS observation data according to the ionospheric model corresponding to the historical GNSS observation data, and then separate the coupled ionospheric delay and differential code deviation information;

[0038] The differential code deviation information separation module is used to separate the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information according to the separated differential code deviation information;

[0039] The variation law fitting module is used to fit the variation law of the receiver differential code deviation according to the separated receiver differential code deviation, and to fit the variation law of the satellite differential code deviation according to the separated satellite differential code deviation;

[0040] The differential code deviation estimation module is used to estimate the receiver differential code deviation estimated value within the period to be modeled according to the change law of the receiver differential code deviation, and to estimate the satellite differential code deviation estimated value within the period to be modeled according to the change law of the satellite differential code deviation;

[0041] The ionospheric model construction module is used to eliminate the receiver differential code bias estimate and the satellite differential code bias estimate in the GNSS observation data within the time period to be modeled according to the receiver differential code bias estimate and the satellite differential code bias estimate, and then construct the corresponding ionospheric model within the time period to be modeled according to the eliminated GNSS observation data.

[0042] Based on the above embodiments, another embodiment of the present invention provides an electronic device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, the ionosphere modeling method described in the above embodiments of the invention is implemented.

[0043] Based on the above embodiments, another embodiment of the present invention provides a storage medium, wherein the storage medium includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the ionosphere modeling method described in the above invention embodiment.

[0044] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0045] The present invention provides an ionospheric modeling method. First, according to a number of historical GNSS observation data of an area to be modeled within a preset time period, coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data are calculated; then, according to an ionospheric model corresponding to the historical GNSS observation data, the ionospheric delay corresponding to the historical GNSS observation data is calculated, and then the coupled ionospheric delay and differential code deviation information are separated; and according to the separated differential code deviation information, the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information are separated.

[0046] It can be seen that the present invention can overcome the problem that the differential code deviation and the ionospheric delay are coupled to each other and the differential code deviation cannot be separated. The ionospheric delay corresponding to the historical GNSS observation data can be calculated according to the ionospheric model corresponding to the historical GNSS observation data, thereby decoupling and separating the coupled ionospheric delay and differential code deviation information. According to the separated differential code deviation data, the differential code deviation estimate within the time period to be modeled can be fitted and estimated; according to the differential code deviation estimate, the differential code deviation estimate in the GNSS observation data within the time period to be modeled is eliminated to obtain pure GNSS observation data, and the ionospheric model corresponding to the time period to be modeled is constructed, which can improve the accuracy of the constructed ionospheric model. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flowchart of an ionospheric modeling method provided by an embodiment of the present invention;

[0048] Figure 2 is a flow chart of the ionospheric model construction of the present invention;

[0049] Figure 3 It is a structural schematic diagram of an ionospheric modeling device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0056] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0057] Embodiment 1

[0058] Please refer to Figure 1 , is a flow chart of an ionospheric modeling method provided by an embodiment of the present invention, comprising the following specific steps:

[0059] S1. Acquire a number of historical GNSS observation data of the area to be modeled within a preset time period; wherein the historical GNSS observation data includes: historical pseudorange observation data and historical carrier observation data of all base station receivers;

[0060] Specifically, the changes in charged particles in the ionosphere are complex. In the process of model building, the existing technology usually assumes that the ionosphere does not change significantly within a certain period of time, and fits the observations within a period of 15 minutes, half an hour, one hour or even two hours into a model. This assumption can achieve good results when solar activity is weak or the ionosphere is quiet, but in years with strong solar activity, around noon local time, or during solar / geomagnetic storms, the ionosphere is more active, and the total electron content can fluctuate by more than a dozen TECUs (Total Electron Content Units) in a short period of time, causing the model established by the above method to have large errors and cannot be applied to actual GNSS operations or other industry production processes.

[0061] The receiver and satellite differential code bias is another factor that restricts the accuracy of the model in the ionosphere modeling process. Since the differential code bias is coupled with the ionospheric delay obtained from the GNSS observations and cannot be separated, it is necessary to separate it from the total electron content of the ionosphere by assuming that the differential code bias is a constant in a short period of time (one day) during the modeling process. However, this assumption is based on the premise that the receiver state and the environment are stable. However, in the actual production process, the differential code bias cannot be guaranteed to be stable due to factors such as the temperature and humidity of the receiver environment, the space radiation in the space environment where the satellite is located, and the service life of the receiver and satellite.

[0062] Considering the strict conditions for the above assumptions, the present invention obtains the high-frequency ionosphere model by first solving the initial value of the differential code deviation between the receiver and the satellite, then gradually establishing the ionosphere model and estimating the time-varying differential code deviation. Figure 2 , is a flow chart of the ionosphere model construction of the present invention, and its specific implementation steps are as follows:

[0063] Step 1: Collect the historical GNSS observation data of all base station receivers in the ionosphere to be modeled area in the previous day, and calculate the center of the area as the modeling reference center position; wherein the historical GNSS observation data includes: historical pseudorange observation data and historical carrier observation data of all base station receivers.

[0064] S2. Calculate the coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data; wherein the differential code deviation information includes: receiver differential code deviation and satellite differential code deviation;

[0065] Preferably, the calculation of the coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data includes: calculating the corresponding geometry-free combined pseudorange observation value based on the historical pseudorange observation data, and calculating the corresponding geometry-free combined carrier observation value based on the historical carrier observation data; calculating the mean of the sum of the geometry-free combined pseudorange observation values ​​and the geometry-free combined carrier observation values ​​within the same preset arc segment, and then calculating the coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data based on the mean and the geometry-free combined carrier observation value.

[0066] Preferably, the coupled ionospheric delay and differential code deviation information is:

[0067]

[0068] in, represents the geometry-free combined carrier observation in meters, STEC represents the ionospheric delay, and f 1 represents the frequency corresponding to the pseudorange observation value without geometric combination, f 2 represents the frequency corresponding to the carrier observation value without geometric combination, c represents the speed of light in vacuum, DCB r,1|2 Indicates that the receiver is at frequency f 1 and frequency f 2 The receiver differential code deviation on Indicates that the satellite is at frequency f 1 and f 2 The satellite differential code bias on It represents the mean of the sum of the geometry-free combined pseudorange observation values ​​and the geometry-free combined carrier observation values ​​within the same preset arc segment.

[0069] Step 2: Using the historical GNSS observation data collected in step 1, use the phase-smoothed pseudorange or non-differenced non-combined PPP method to calculate the ionospheric delay and differential code deviation information corresponding to each historical GNSS observation value.

[0070] In a specific embodiment, the calculation process of the phase smoothing pseudorange method is given. First, the geometry-free combined observation value of the pseudorange and the carrier is obtained by using the historical GNSS observation data:

[0071]

[0072] in, and represents the geometry-free combined pseudorange observation value and geometry-free combined carrier observation value in meters, STEC represents the slant path total electron content (Slant TEC) on the GNSS signal path, and f 1 and f 2represents the corresponding frequency of the two observed values ​​involved in the calculation, c is the speed of light in vacuum, DCB r,1|2 and Respectively represent the receiver and satellite at frequency f 1 and f 2 The differential code deviation on r,f and are the carrier hardware delays of the receiver and satellite, respectively, f represents the wavelength of the carrier with frequency f, represents the ambiguity cycle of the carrier observation value, and t represents the observation time.

[0073] In formula (1) b r,f and It is assumed to be stable within an observation arc segment. Therefore, after eliminating the cycle slip, the observation values ​​within the same arc segment are averaged to obtain the following relationship:

[0074]

[0075] Where n is the number of observations in a continuous arc segment, It represents the mean value of the sum of the geometric combination-free pseudorange observation value and the geometric combination-free carrier observation value in a continuous arc segment. After obtaining this mean value, the combined formula (1) can be obtained:

[0076]

[0077] STEC (as ionospheric delay) can be further obtained by phase-smoothing the pseudorange observations:

[0078]

[0079] The above formula (4) is the coupled ionospheric delay and differential code deviation information.

[0080] S3. Calculating the ionospheric delay corresponding to the historical GNSS observation data according to the ionospheric model corresponding to the historical GNSS observation data, and then separating the coupled ionospheric delay and differential code deviation information;

[0081] Preferably, the ionospheric delay corresponding to the historical GNSS observation data is calculated according to the ionospheric model corresponding to the historical GNSS observation data, and then the coupled ionospheric delay and differential code deviation information are separated, including: judging whether there is a corresponding ionospheric model for the historical GNSS observation data, and when it is determined that there is a corresponding ionospheric model for the historical GNSS observation data, calculating the puncture point coordinates of the historical GNSS observation data at the corresponding ionospheric model height according to the ionospheric model corresponding to the historical GNSS observation data; calculating the vertical path value corresponding to the historical GNSS observation data according to the puncture point coordinates; calculating the ionospheric projection function value corresponding to the historical GNSS observation data, and then converting the vertical path value into a corresponding inclined path value according to the ionospheric projection function value; using the inclined path value as the ionospheric delay corresponding to the historical GNSS observation data, and then separating the coupled ionospheric delay and differential code deviation information.

[0082] Preferably, the ionospheric delay corresponding to the historical GNSS observation data is calculated according to the ionospheric model corresponding to the historical GNSS observation data, and then the coupled ionospheric delay and differential code deviation information are separated, and further includes: when it is determined that there is no corresponding ionospheric model for the historical GNSS observation data, assuming that the receiver differential code deviation and the satellite differential code deviation corresponding to the historical GNSS observation data are the same within a preset time period, and then solving the ionospheric model corresponding to the historical GNSS observation data according to the preset ionospheric model and differential code deviation solution equation; The invention relates to an ionospheric model corresponding to the historical GNSS observation data, and calculates the puncture point coordinates of the historical GNSS observation data at the corresponding ionospheric model height; calculates the vertical path value corresponding to the historical GNSS observation data according to the puncture point coordinates; calculates the ionospheric projection function value corresponding to the historical GNSS observation data, and then converts the vertical path value into a corresponding inclined path value according to the ionospheric projection function value; uses the inclined path value as the ionospheric delay corresponding to the historical GNSS observation data, and then separates the coupled ionospheric delay and differential code deviation information.

[0083] S4. Separating the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information according to the separated differential code deviation information;

[0084] Preferably, the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information are separated according to the separated differential code deviation information, including: according to the separated differential code deviation information, setting the sum of the satellite differential code deviation in the differential code deviation information to zero, solving for the corresponding receiver differential code deviation, and then separating the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information.

[0085] Step 3: If the existing ionospheric model product at the time corresponding to the historical GNSS observations in the modeling area is available, the product can be used to separate the differential code bias between the receiver and the satellite from the ionospheric delay to obtain the time-varying differential code bias between the receiver and the satellite. Using the existing ionospheric model product as a known value, subtract the ionospheric delay value from the phase-smoothed pseudorange observation calculated in step 2 to obtain the combined value of the differential code bias between the receiver and the satellite.

[0086] The two are separated by the zero mean assumption. Considering the time-varying characteristics of the two, the receiver and satellite differential code biases are estimated for each epoch. Since the differential code bias changes slowly, the modified value of the receiver and satellite differential code bias of the previous epoch is used as a constraint for Kalman filter estimation to control its change rate. After a period of time, a stable Kalman filter output result can be obtained. The specific implementation process is as follows:

[0087] 1. Calculate the ionospheric model results corresponding to all historical GNSS observations in the same epoch, and obtain the vertical path TEC corresponding to the historical GNSS observations, which is recorded as Where s is the satellite number, r is the receiver number, and t is the current epoch.

[0088] First, calculate the puncture point coordinates of the historical GNSS observations at the ionospheric model height:

[0089] z=π / 2-El

[0090]

[0091] α=zz'

[0092]

[0093]

[0094] Where: A is the satellite azimuth, El is the satellite altitude, R E is the radius of the earth (6378km), H is the height of the puncture point, which is set to 506.7km here. and λ are the latitude and longitude of the station, and λ IPPis the latitude and longitude of the puncture point. Then the vertical path is calculated using the ionosphere model, and the specific calculation method varies depending on the model.

[0095] 2. Calculate the ionospheric projection function value MF corresponding to the historical GNSS observation value, and convert the vertical path model value in step 1 Convert to slope path model value

[0096]

[0097]

[0098] Where R is the radius of the earth, H 0 =506.7KM, a=0.9782.

[0099] 3. Based on equation (3) in step 2, remove The DCB obtained after the ionospheric STEC is expressed r,1|2 and The combined value of all satellites The sum is zero, for DCB r,1|2 and Separation is calculated as follows:

[0100]

[0101]

[0102] L=HX (7)

[0103] Where L represents all DCB calculated by using equation (3) and equation (6) in step 2 r,1|2 and The combination value of , H is the design matrix, the last row represents the zero mean constraint, and X is the DCB of the current epoch to be determined r,1|2 (t) and Values, where X is the first DCB behind r,1|2 (t).

[0104] 4. Use Kalman filtering to calculate each epoch sequentially to obtain the time-varying receiver differential code bias and satellite differential code bias values.

[0105] Step 4: If the corresponding ionospheric model product cannot be obtained in step 3, first assume that the receiver differential code bias and the satellite differential code bias are the same within a day, and use the least squares method to solve the ionospheric mathematical model parameters and the differential code bias together to achieve the purpose of separating the two.

[0106] Then, the obtained ionospheric mathematical model is used to solve the time-varying receiver differential code bias and the satellite differential code bias using the method in step 3. The phase-smoothed pseudorange observations obtained by equation (3) in step 2 are used to establish the ionospheric model and differential code bias solution equations. In this equation, there is a set of ionospheric model parameters for each time period, and each satellite and receiver uses the same differential code bias parameter within a day:

[0107]

[0108]

[0109]

[0110] L=HX (8)

[0111] Among them, ion i (t n ) indicates that at t n The DCB under the ionospheric model and constant assumption can be obtained by the above method. r,1|2 and In order to obtain DCB in time-varying state r,1|2 and Substitute the ionosphere model in the above formula into step 3 and obtain the time-varying DCB according to the method in step 3 r,1|2 (t) and

[0112] S5. According to the separated receiver differential code deviation, fitting is performed to obtain a variation law of the receiver differential code deviation, and according to the separated satellite differential code deviation, fitting is performed to obtain a variation law of the satellite differential code deviation;

[0113] Step 5: Analyze the time-varying receiver differential code deviation and satellite differential code deviation obtained in step 3 or step 4, and use mathematical model fitting or time-frequency analysis methods to find the variation law of each receiver differential code deviation and satellite differential code deviation. Since the receiver differential code deviation is mainly affected by temperature and the satellite differential code deviation is mainly affected by equipment aging, a simple polynomial can be used for fitting, and the fitting result is:

[0114]

[0115] Among them, A i represents the polynomial coefficient, n represents the polynomial order, and t represents the local time (in seconds), which is obtained by fitting the historically collected receiver DCB data using the least squares method.

[0116] S6. According to the variation law of the receiver differential code deviation, an estimated value of the receiver differential code deviation in the period to be modeled is estimated; according to the variation law of the satellite differential code deviation, an estimated value of the satellite differential code deviation in the period to be modeled is estimated;

[0117] Step 6: Using the variation law obtained in step 5, within the required modeling period, according to the variation law of the receiver differential code deviation, the estimated value of the receiver differential code deviation is estimated, and according to the variation law of the satellite differential code deviation, the estimated value of the satellite differential code deviation is estimated.

[0118] S7. According to the receiver differential code bias estimate and the satellite differential code bias estimate, the receiver differential code bias estimate and the satellite differential code bias estimate are eliminated from the GNSS observation data within the time period to be modeled, and then the ionospheric model corresponding to the time period to be modeled is constructed according to the eliminated GNSS observation data.

[0119] Preferably, the ionospheric modeling method further includes: eliminating ionospheric delays in the GNSS observation data based on the constructed ionospheric model and the corresponding GNSS observation data, and then performing GNSS positioning based on the eliminated GNSS observation data.

[0120] Step 7: Eliminate the estimated receiver differential code bias and the estimated satellite differential code bias from the GNSS observations in the period to be modeled, and then estimate the pure ionospheric delay information for modeling. The Kalman filter method is used in the modeling process, and the ionospheric delay model parameters and the differential code bias between the receiver and the satellite are estimated at the same time.

[0121] According to the data obtained from step 1 to step 5, the ionospheric model parameters within the UHF modeling period (within 1 s) are calculated, and then the initial value of the differential code deviation between the receiver and the satellite within this period is estimated using formula (9). The influence of the differential code deviation is eliminated using formula (3) to obtain the ionospheric delay value, and the equation described in formula (8) and the Kalman filter method are used to perform ionospheric modeling, DCB r,1|2 (t) and The solution is finally added to the differential code deviation law estimation process of step 5, and steps 5 and 6 are repeated. Finally, according to the constructed ionospheric model and the corresponding GNSS observation data, the ionospheric delay in the GNSS observation data is eliminated, and then GNSS positioning is performed according to the eliminated GNSS observation data.

[0122] Embodiment 2

[0123] Please refer to Figure 3, is a structural schematic diagram of an ionospheric modeling device provided by an embodiment of the present invention, the device comprising: a historical observation data acquisition module, a coupling data calculation module, a coupling data separation module, a differential code deviation information separation module, a change law fitting module, a differential code deviation estimation module and an ionospheric model construction module;

[0124] The historical observation data acquisition module is used to acquire a number of historical GNSS observation data of the area to be modeled within a preset time period; wherein the historical GNSS observation data includes: historical pseudo-range observation data and historical carrier observation data of all base station receivers;

[0125] The coupled data calculation module is used to calculate the coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data; wherein the differential code deviation information includes: receiver differential code deviation and satellite differential code deviation;

[0126] The coupled data separation module is used to calculate the ionospheric delay corresponding to the historical GNSS observation data according to the ionospheric model corresponding to the historical GNSS observation data, and then separate the coupled ionospheric delay and differential code deviation information;

[0127] The differential code deviation information separation module is used to separate the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information according to the separated differential code deviation information;

[0128] The variation law fitting module is used to fit the variation law of the receiver differential code deviation according to the separated receiver differential code deviation, and to fit the variation law of the satellite differential code deviation according to the separated satellite differential code deviation;

[0129] The differential code deviation estimation module is used to estimate the receiver differential code deviation estimated value within the period to be modeled according to the change law of the receiver differential code deviation, and to estimate the satellite differential code deviation estimated value within the period to be modeled according to the change law of the satellite differential code deviation;

[0130] The ionospheric model construction module is used to eliminate the receiver differential code bias estimate and the satellite differential code bias estimate in the GNSS observation data within the time period to be modeled according to the receiver differential code bias estimate and the satellite differential code bias estimate, and then construct the corresponding ionospheric model within the time period to be modeled according to the eliminated GNSS observation data.

[0131] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0132] Those skilled in the art can clearly understand that, for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0133] Embodiment 3

[0134] Accordingly, an embodiment of the present invention provides an electronic device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the ionosphere modeling method described in the above-mentioned embodiment of the invention when executing the computer program.

[0135] The electronic device may be a computing device such as a desktop computer, a notebook, a palm computer, a cloud server, etc. The device may include, but is not limited to, a processor and a memory.

[0136] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the device, and various interfaces and lines are used to connect various parts of the entire device.

[0137] Embodiment 4

[0138] Accordingly, an embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the ionosphere modeling method described in the above-mentioned embodiment of the invention.

[0139] The memory can be used to store the computer program, and the processor realizes various functions of the device by running or executing the computer program stored in the memory and calling the 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 for a function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (FlashCard), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0140] The storage medium is a computer-readable storage medium, and the computer program is stored in the computer-readable storage medium. When the computer program is executed by the processor, the steps of each method embodiment described above can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and 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, computer-readable media do not include electric carrier signals and telecommunication signals.

[0141] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An ionospheric modeling method, characterized in that: include: Acquire a number of historical GNSS observation data of the area to be modeled within a preset time period; wherein the historical GNSS observation data includes: historical pseudorange observation data and historical carrier observation data of all base station receivers; Calculate the coupled ionospheric delay and differential code bias information corresponding to each historical GNSS observation data; wherein the differential code bias information includes: receiver differential code bias and satellite differential code bias; Calculating the ionospheric delay corresponding to the historical GNSS observation data according to the ionospheric model corresponding to the historical GNSS observation data, and then separating the coupled ionospheric delay and differential code deviation information; According to the separated differential code deviation information, separating the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information; According to the separated receiver differential code deviation, the variation law of the receiver differential code deviation is obtained by fitting, and according to the separated satellite differential code deviation, the variation law of the satellite differential code deviation is obtained by fitting; According to the variation law of the receiver differential code deviation, the estimated value of the receiver differential code deviation in the period to be modeled is estimated; according to the variation law of the satellite differential code deviation, the estimated value of the satellite differential code deviation in the period to be modeled is estimated; According to the receiver differential code bias estimate and the satellite differential code bias estimate, the receiver differential code bias estimate and the satellite differential code bias estimate are eliminated from the GNSS observation data within the period to be modeled, and then the corresponding ionospheric model within the period to be modeled is constructed based on the eliminated GNSS observation data.

2. The ionospheric modeling method according to claim 1, characterized in that: Also includes: According to the constructed ionospheric model and the corresponding GNSS observation data, the ionospheric delay in the GNSS observation data is eliminated, and then GNSS positioning is performed based on the eliminated GNSS observation data.

3. The ionospheric modeling method according to claim 1, characterized in that: The calculating of coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data includes: According to the historical pseudorange observation data, a corresponding geometry-free combined pseudorange observation value is calculated, and according to the historical carrier observation data, a corresponding geometry-free combined carrier observation value is calculated; The mean of the sum of the geometry-free combined pseudorange observation values ​​and the geometry-free combined carrier observation values ​​within the same preset arc segment is calculated, and then the coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data is calculated based on the mean and the geometry-free combined carrier observation values.

4. The ionospheric modeling method according to claim 3, characterized in that: The coupled ionospheric delay and differential code deviation information is: in, represents the geometry-free carrier observation in meters, STEC represents the ionospheric delay, f1 represents the frequency corresponding to the geometry-free pseudorange observation, f2 represents the frequency corresponding to the geometry-free carrier observation, c represents the speed of light in vacuum, DCB r,1|2 represents the receiver differential code deviation at frequency f1 and frequency f2, represents the satellite differential code deviation at frequencies f1 and f2, It represents the mean of the sum of the geometry-free combined pseudorange observation values ​​and the geometry-free combined carrier observation values ​​within the same preset arc segment.

5. The ionospheric modeling method according to claim 1, characterized in that: The step of calculating the ionospheric delay corresponding to the historical GNSS observation data according to the ionospheric model corresponding to the historical GNSS observation data, and then separating the coupled ionospheric delay and differential code deviation information includes: Determine whether there is a corresponding ionospheric model for the historical GNSS observation data; when it is determined that there is a corresponding ionospheric model for the historical GNSS observation data, calculate the puncture point coordinates of the historical GNSS observation data at the corresponding ionospheric model height according to the ionospheric model corresponding to the historical GNSS observation data; Calculating the vertical path value corresponding to the historical GNSS observation data according to the puncture point coordinates; Calculating an ionospheric projection function value corresponding to the historical GNSS observation data, and then converting the vertical path value into a corresponding inclined path value according to the ionospheric projection function value; The tilt path value is used as the ionospheric delay corresponding to the historical GNSS observation data, and then the coupled ionospheric delay and differential code deviation information are separated.

6. The ionospheric modeling method according to claim 5, characterized in that: The step of calculating the ionospheric delay corresponding to the historical GNSS observation data according to the ionospheric model corresponding to the historical GNSS observation data, and then separating the coupled ionospheric delay and differential code deviation information, further includes: When it is determined that there is no corresponding ionospheric model for the historical GNSS observation data, it is assumed that the receiver differential code bias and the satellite differential code bias corresponding to the historical GNSS observation data are the same within a preset period of time, and then the ionospheric model corresponding to the historical GNSS observation data is solved according to the preset ionospheric model and the solution equation of the differential code bias; According to the ionosphere model corresponding to the historical GNSS observation data, calculating the puncture point coordinates of the historical GNSS observation data at the corresponding ionosphere model height; Calculating the vertical path value corresponding to the historical GNSS observation data according to the puncture point coordinates; Calculating an ionospheric projection function value corresponding to the historical GNSS observation data, and then converting the vertical path value into a corresponding inclined path value according to the ionospheric projection function value; The tilt path value is used as the ionospheric delay corresponding to the historical GNSS observation data, and then the coupled ionospheric delay and differential code deviation information are separated.

7. The ionospheric modeling method according to claim 1, characterized in that: The step of separating the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information according to the separated differential code deviation information includes: According to the separated differential code deviation information, the sum of the satellite differential code deviations in the differential code deviation information is set to zero, and the corresponding receiver differential code deviation is obtained by solving, and then the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information are separated.

8. An ionospheric modeling device, characterized in that: include: Historical observation data acquisition module, coupled data calculation, coupled data separation module, differential code deviation information separation module, change law fitting module, differential code deviation estimation module and ionospheric model construction module; The historical observation data acquisition module is used to acquire a number of historical GNSS observation data of the area to be modeled within a preset time period; wherein the historical GNSS observation data includes: historical pseudo-range observation data and historical carrier observation data of all base station receivers; The coupled data calculation module is used to calculate the coupled ionospheric delay and differential code deviation information corresponding to each historical GNSS observation data; wherein the differential code deviation information includes: receiver differential code deviation and satellite differential code deviation; The coupled data separation module is used to calculate the ionospheric delay corresponding to the historical GNSS observation data according to the ionospheric model corresponding to the historical GNSS observation data, and then separate the coupled ionospheric delay and differential code deviation information; The differential code deviation information separation module is used to separate the receiver differential code deviation and the satellite differential code deviation in the differential code deviation information according to the separated differential code deviation information; The variation law fitting module is used to fit the variation law of the receiver differential code deviation according to the separated receiver differential code deviation, and to fit the variation law of the satellite differential code deviation according to the separated satellite differential code deviation; The differential code deviation estimation module is used to estimate the receiver differential code deviation estimated value within the period to be modeled according to the change law of the receiver differential code deviation, and to estimate the satellite differential code deviation estimated value within the period to be modeled according to the change law of the satellite differential code deviation; The ionospheric model construction module is used to eliminate the receiver differential code bias estimate and the satellite differential code bias estimate in the GNSS observation data within the time period to be modeled according to the receiver differential code bias estimate and the satellite differential code bias estimate, and then construct the corresponding ionospheric model within the time period to be modeled according to the eliminated GNSS observation data.

9. An electronic device, characterized in that: The invention comprises a processor, a memory and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the ionosphere modeling method according to any one of claims 1 to 7 when executing the computer program.

10. A storage medium, characterized in that: The storage medium includes a stored computer program, wherein when the computer program is executed, the device where the storage medium is located is controlled to execute the ionosphere modeling method according to any one of claims 1 to 7.

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