Method and device for calculating electron density and electron content of ionized layer

Abstract

The invention discloses a method and a device for calculating the electron density and the electron content of an ionized layer. The method for calculating the electron density of the ionized layer comprises the following steps: acquiring an electron content observation value of an ionized layer puncture point and an ionized layer electron density background value of a three-dimensional network; performing data assimilation on the electron content observation value and the ionosphere electron density background value to obtain an expression of an ionosphere electron density analysis value; constructing an observation error analysis function according to the expression of the ionosphere electron density analysis value, the electron content observation value and the ionosphere electron density background value; minimizing an observation error analysis function as a target function, and solving to obtain a target position variance factor; and calculating the corrected ionosphere electron density analysis value according to the target position variance factor. According to the method, the calculation result of the ionosphere electron density is calibrated, and the distribution condition of electrons in the space can be described more accurately, so that the prediction precision of the model is improved.

Description

Technical Field

[0001] The present invention relates to the field of GNSS atmosphere monitoring technology, and in particular to a method and device for calculating ionospheric electron density and electron content. Background Art

[0002] The ionosphere is an important part of the solar-terrestrial space environment. Various phenomena in the ionosphere are monitored and studied to reveal their temporal and spatial variation laws and physical mechanisms. The distribution of ionospheric electron density (IED) is studied in particular, as it plays an important role in radio and satellite communications and satellite positioning.

[0003] In the calculation of ionospheric electron density, it is very important to have prior information of IED global empirical models, such as IRI and NeQuick global empirical models. Global empirical models are usually based on simplified assumptions and may not be accurate enough in describing how electrons are distributed in actual systems. The prediction accuracy of the model is not high, resulting in inaccurate calculated ionospheric electron density. Summary of the invention

[0004] The present invention provides a method and device for calculating the electron density and electron content of the ionosphere, so as to solve the technical problem that the calculated electron density and electron content of the ionosphere are inaccurate due to the low prediction accuracy of the full empirical model.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a method for calculating ionospheric electron density, including:

[0006] Obtaining the electron content observation value of the ionospheric puncture point and the ionospheric electron density background value of the three-dimensional network; wherein the three-dimensional regular network is provided by a global empirical model;

[0007] According to the electron content observation value and the ionospheric electron density background value, data assimilation is performed to obtain an expression of the ionospheric electron density analysis value; wherein the expression is an expression of the ionospheric electron density with respect to the position variance factor;

[0008] Constructing an observation error analysis function according to the expression of the ionospheric electron density analysis value, the electron content observation value and the ionospheric electron density background value;

[0009] Taking the minimization of the observation error analysis function as the objective function, the variance factor of the target position is obtained by solving;

[0010] According to the target position variance factor, the corrected ionospheric electron density analysis value is calculated through the expression of the ionospheric electron density analysis value.

[0011] As a preferred solution, before obtaining the electron content observation value of the ionospheric puncture point, it also includes:

[0012] Acquiring a carrier phase observation value of the ionospheric puncture point by a dual-frequency GNSS receiver;

[0013] Calculating the electron content observation value of the ionospheric puncture point according to the carrier phase observation value;

[0014] The calculation formula of the electron content observation value is:

[0015]

[0016] Where V R represents the electron content observation value; L represents the carrier phase observation value; f1 and f2 are the signal frequencies used by the dual-frequency receiver; B is the pseudorange hardware delay; SDCB is the dual-frequency code deviation of the satellite; RDCB is the dual-frequency code deviation of the dual-frequency receiver.

[0017] As a preferred solution, the data assimilation is performed according to the electron content observation value and the ionospheric electron density background value, including:

[0018] Taking the latitude and longitude position of the ionospheric puncture point as the reference position, the electron content observation value and the ionospheric electron density background value are assimilated to obtain the following expression of the ionospheric electron density analysis value:

[0019] N A (λ i,j ,φ i,j ,h k )=N B (λ i,j ,φ i,j ,h k )+G(V R (λ0,φ0))-HN B (λ i,j ,φ i,j ,h k );

[0020] i=1...nI, j=1...nJ, k=1...K;

[0021] G=BH T (R+HBH T ) -1 ;

[0022] R=P -1 ;

[0023]

[0024] B=σ B I;

[0025] In the formula, λ i,j Indicates the longitude of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; φ i,j Indicates the dimension of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; h k Represents the height of the grid point with index k in the height direction of the three-dimensional network; N A (λ i,j ,φ i,j ,h k ) represents the position (λ i,j ,φ i,j ,h k ) ionospheric electron density analysis value; N B (λ i,j ,φ i,j ,h k ) represents the position (λ i,j ,φ i,j ,h k ) is the ionospheric electron density background value at ; nI represents the number of all grids in the longitude direction of the three-dimensional grid; nJ represents the number of all grids in the dimension direction of the three-dimensional grid; K represents the number of all grids in the height direction of the three-dimensional grid; G represents the assimilation weight matrix; λ0 represents the longitude of the reference position; φ0 represents the dimension of the reference position; H represents the observation value submatrix; B represents the observation value coefficient matrix; represents the observation value covariance matrix; P represents the observation value weight matrix; represents random error; σ B represents the position method factor; I is the unit matrix.

[0026] As a preferred solution, the expression of the observation error analysis function is:

[0027] f(N A )=

[0028] ||V R (λ0,φ0)-HN A (λ i,j ,φ i,j ,h k )||2+||N A (λ i,j ,φ i,j ,h k )-N B (λ i,j ,φ i,j ,h k )||;

[0029] In the formula, f(N A ) represents the observation error analysis function.

[0030] As a preferred solution, the objective function is to minimize the observation error analysis function and solve the target position variance factor, including:

[0031] Under the condition that the position variance factor is greater than 0, the objective function is to minimize the observation error analysis function and solve the target position variance factor;

[0032] Among them, the solution formula of the target position variance factor is:

[0033]

[0034] As a preferred solution, the three-dimensional network has a longitude resolution of 0.5°, a latitude resolution of 0.5°, an altitude resolution of 50 kilometers, and an altitude range of 100 kilometers to 2000 kilometers above sea level.

[0035] The present invention also provides an electron content calculation method, comprising:

[0036] Obtaining corrected ionospheric electron density analysis values ​​of grid points corresponding to the grid where the ionospheric puncture point to be solved is located and the grids on all altitude layers overlapping with the grid where the ionospheric puncture point is located on the horizontal plane; wherein the grid is a grid in a three-dimensional regular network provided by a global empirical model; the grid points are grid points in a three-dimensional regular network provided by the global empirical model; the corrected ionospheric electron density analysis values ​​are calculated according to the electron content calculation method described in the above-mentioned embodiment of the invention;

[0037] The electron content of the ionospheric puncture point is calculated based on all the corrected ionospheric electron density analysis values.

[0038] As a preferred solution, the electron content of the ionospheric puncture point is calculated according to all the corrected ionospheric electron density analysis values, including:

[0039] For each altitude layer, a weighted average value of the corrected ionospheric electron density analysis value corresponding to the altitude layer is calculated;

[0040] Summing the weighted average values ​​corresponding to all altitude layers to obtain the electron content of the ionospheric puncture point;

[0041] The calculation formula of the electron content of the ionospheric puncture point is:

[0042]

[0043] Where V B represents the electron content at the ionospheric puncture point; i,j Indicates the longitude of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; φ i,jIndicates the dimension of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; h k Represents the height of the grid point with index k in the height direction of the three-dimensional network; N A (λ i,j ,φ i,j ,h k ) represents the position (λ i,j ,φ i,j ,h k ) ionospheric electron density analysis value; w t,k It represents the weight value of the tth corrected ionospheric electron density analysis value corresponding to the kth altitude layer; K represents the total number of altitude layers; T represents the total number of corrected ionospheric electron density analysis values ​​corresponding to each altitude layer.

[0044] On the basis of the above-mentioned embodiment, another embodiment of the present invention provides an ionospheric electron density calculation device, comprising: a first data acquisition module, a data assimilation module and a correction module;

[0045] The first data acquisition module is used to obtain the electron content observation value of the ionospheric puncture point and the ionospheric electron density background value of the three-dimensional network; wherein the three-dimensional regular network is provided by a global empirical model;

[0046] The data assimilation module is used to perform data assimilation according to the electron content observation value and the ionospheric electron density background value to obtain an expression of the ionospheric electron density analysis value; wherein the expression is an expression of the ionospheric electron density with respect to the position variance factor;

[0047] The correction module is used to construct an observation error analysis function according to the expression of the ionospheric electron density analysis value, the electron content observation value and the ionospheric electron density background value; take minimization of the observation error analysis function as the objective function, and solve to obtain the target position variance factor; and calculate the corrected ionospheric electron density analysis value according to the target position variance factor through the expression of the ionospheric electron density analysis value.

[0048] Based on the above embodiment, another embodiment of the present invention provides an electronic content calculation device, the electronic content calculation device comprising: a second data acquisition module and an electronic content calculation module;

[0049] The second data acquisition module is used to obtain the corrected ionospheric electron density analysis value of the grid points corresponding to the grid where the ionospheric puncture point to be solved is located and the grids on all altitude layers overlapping with the grid where the ionospheric puncture point is located on the horizontal plane; wherein the grid is a grid in a three-dimensional regular network provided by a global empirical model; the grid points are grid points in a three-dimensional regular network provided by the global empirical model; the corrected ionospheric electron density analysis value is calculated according to the electron content calculation method as described in the above-mentioned embodiment of the invention;

[0050] The electron content calculation module is used to calculate the electron content of the ionospheric puncture point based on all the corrected ionospheric electron density analysis values.

[0051] Based on the above embodiments, another embodiment of the present invention provides a terminal 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 electronic content calculation method described in the above invention embodiment is implemented.

[0052] Based on the above embodiment, another 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 electronic content calculation method described in the above invention embodiment.

[0053] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0054] The present invention obtains the electron content observation value of the ionospheric puncture point and the ionospheric electron density background value of the three-dimensional network; performs data assimilation on the electron content observation value and the ionospheric electron density background value to obtain the expression of the ionospheric electron density analysis value; constructs the observation error analysis function according to the expression of the ionospheric electron density analysis value, the electron content observation value and the ionospheric electron density background value; takes the minimization of the observation error analysis function as the objective function, and solves to obtain the target position variance factor; according to the target position variance factor, the ionospheric electron density is calibrated through the expression of the ionospheric electron density analysis value to obtain the ionospheric electron density analysis value after calculation and correction. The present invention calibrates the calculation result of the ionospheric electron density, which can more accurately describe the distribution of electrons in space, thereby improving the prediction accuracy of the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a flow chart of a method for calculating ionospheric electron density provided by one embodiment of the present invention;

[0056] Figure 2is a flow chart of an electron content calculation method provided by one embodiment of the present invention;

[0057] Figure 3 It is a structural schematic diagram of an ionospheric electron density calculation device provided by one embodiment of the present invention;

[0058] Figure 4 It is a schematic diagram of the structure of an electronic content calculation device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] Embodiment 1

[0061] Please refer to Figure 1 , is a flow chart of a method for calculating ionospheric electron density provided by an embodiment of the present invention, comprising:

[0062] S101. Obtaining the electron content observation value of the ionospheric puncture point and the ionospheric electron density background value of the three-dimensional network; wherein the three-dimensional regular network is provided by a global empirical model.

[0063] In step S101, an ionospheric puncture point is selected to obtain the electron content observation value of the ionospheric puncture point. The three-dimensional network provided by the global empirical model includes the ionospheric electron density background value of each grid point, and the ionospheric electron density background values ​​of all grid points in the three-dimensional network are obtained.

[0064] In a preferred embodiment, before obtaining the electron content observation value of the ionospheric puncture point, the method further includes:

[0065] Acquiring a carrier phase observation value of the ionospheric puncture point by a dual-frequency GNSS receiver;

[0066] Calculating the electron content observation value of the ionospheric puncture point according to the carrier phase observation value;

[0067] The calculation formula of the electron content observation value is:

[0068]

[0069] Where V Rrepresents the electron content observation value; L represents the carrier phase observation value; f1 and f2 are the signal frequencies used by the dual-frequency receiver; B is the pseudorange hardware delay; SDCB is the dual-frequency code deviation of the satellite; RDCB is the dual-frequency code deviation of the dual-frequency receiver.

[0070] In this embodiment, the electron content observation value at the ionospheric piercing point can be calculated by acquiring each bit observation value under the carrier of the ionospheric piercing point through a dual-frequency GNSS receiver.

[0071] In a preferred embodiment, the three-dimensional network has a longitude resolution of 0.5°, a latitude resolution of 0.5°, an altitude resolution of 50 kilometers, and an altitude range of 100 kilometers to 2000 kilometers above sea level.

[0072] In this embodiment, the three-dimensional network obtained from the global empirical model is an equidistant regular spherical network, which refers to a three-dimensional regular network of ionospheric electron density. The longitude and latitude of the network are 0.5°×0.5°, and it consists of 39 altitude layers, ranging from 100 kilometers to 2000 kilometers above sea level, with a fixed step size of 50 kilometers.

[0073] S102. Perform data assimilation based on the electron content observation value and the ionospheric electron density background value to obtain an expression for the ionospheric electron density analysis value; wherein the expression is an expression for the ionospheric electron density with respect to the position variance factor.

[0074] It should be noted that the modeling time of the global empirical model is divided into 10-minute subintervals. In the middle of each subinterval, the three-dimensional regular network of ionospheric electron density is received from the global empirical model online service. In each hour interval, there are 6 subintervals, and the electron content observations of each subinterval are assimilated into the background ionospheric electron density grid in the middle of the subinterval, that is, the three-dimensional regular network.

[0075] In a preferred embodiment, performing data assimilation based on the electron content observation value and the ionospheric electron density background value includes:

[0076] Taking the latitude and longitude position of the ionospheric puncture point as the reference position, the electron content observation value and the ionospheric electron density background value are assimilated to obtain the following expression of the ionospheric electron density analysis value:

[0077] N A (λ i,j ,φ i,j ,h k )=N B (λ i,j ,φ i,j ,h k )+G(V R(λ0,φ0))-HN B (λ i,j ,φ i,j ,h k );

[0078] i=1...nI, j=1...nJ, k=1...K;

[0079] G=BH T (R+HBH T ) -1 ;

[0080] R=P -1 ;

[0081] P = diag (sin 2 (ε r s2 ));

[0082] B=σ B I;

[0083] In the formula, λ i,j Indicates the longitude of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; φ i,j Indicates the dimension of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; h k Represents the height of the grid point with index k in the height direction of the three-dimensional network; N A (λ i,j ,φ i,j ,h k ) represents the position (λ i,j ,φ i,j ,h k ) ionospheric electron density analysis value; N B (λ i,j ,φ i,j ,h k ) represents the position (λ i,j ,φ i,j ,h k ) is the ionospheric electron density background value at ; nI represents the number of all grids in the longitude direction of the three-dimensional grid; nJ represents the number of all grids in the dimension direction of the three-dimensional grid; K represents the number of all grids in the height direction of the three-dimensional grid; G represents the assimilation weight matrix; λ0 represents the longitude of the reference position; φ0 represents the dimension of the reference position; H represents the observation value submatrix; B represents the observation value coefficient matrix; represents the observation value covariance matrix; P represents the observation value weight matrix; represents random error; σ B represents the position method factor; I is the unit matrix.

[0084] It should be noted that this embodiment uses the optimal interpolation method to map the ionospheric electron density background value on the equidistant regular spherical grid to the electron content observation value of the ionospheric puncture point, and calibrates through data assimilation. The random error is allocated based on experience.

[0085] In this embodiment, during data assimilation, it is necessary to construct an observation covariance matrix and B represents an observation coefficient matrix. In each subinterval, the observation covariance matrix can be obtained by inverting the observation weight matrix. During data assimilation, it is also necessary to establish a connection between the background and the observation variance, which requires a position variance factor. Finally, through data assimilation, an expression of the ionospheric electron density analysis value is constructed, which is an expression about the position variance factor.

[0086] S103. Construct an observation error analysis function according to the expression of the ionospheric electron density analysis value, the electron content observation value and the ionospheric electron density background value.

[0087] In step S103, in order to solve the optimization problem of finding the optimal position variance factor, it is necessary to construct an observation error analysis function based on the expression of the ionospheric electron density analysis value, the electron content observation value and the ionospheric braid density background value.

[0088] In a preferred embodiment, the expression of the observation error analysis function is:

[0089] f(N A )=

[0090] ||V R (λ0,φ0)-HN A (λ i,j ,φ i,j ,h k )||2+||N A (λ i,j ,φ i,j ,h k )-N B (λ i,j ,φ i,j ,h k )||;

[0091] In the formula, f(N A ) represents the observation error analysis function.

[0092] S104, taking the minimization of the observation error analysis function as the objective function, solving and obtaining the target position variance factor.

[0093] In step S104, the position variance factor that makes the observation error analysis function obtain the minimum value is the target position variance factor to be found.

[0094] In a preferred embodiment, the minimization of the observation error analysis function is used as the objective function to solve the target position variance factor, including:

[0095] Under the condition that the position variance factor is greater than 0, the objective function is to minimize the observation error analysis function and solve the target position variance factor;

[0096] Among them, the solution formula of the target position variance factor is:

[0097]

[0098] In this embodiment, an intra-point algorithm is used to solve the optimization problem. The basis of this method is to add constraints as functions to the objective function and use the quasi-Newton method to minimize the newly obtained objective function.

[0099] S105. Calculate the corrected ionospheric electron density analysis value according to the target position variance factor and the expression of the ionospheric electron density analysis value.

[0100] In this embodiment, the target position variance is substituted into the ionospheric electron density expression to calculate and obtain the corrected ionospheric electron density analysis value.

[0101] Embodiment 2

[0102] Please refer to Figure 2 , is a flow chart of a method for calculating electron content provided by an embodiment of the present invention, the method for calculating electron content comprising:

[0103] S201, obtaining corrected ionospheric electron density analysis values ​​of grid points corresponding to the grid where the ionospheric puncture point to be solved is located and the grids on all altitude layers overlapping with the grid where the ionospheric puncture point is located on the horizontal plane; wherein the grid is a grid in a three-dimensional regular network provided by a global empirical model; the grid points are grid points in a three-dimensional regular network provided by the global empirical model; the corrected ionospheric electron density analysis values ​​are calculated according to the electron content calculation method as described in the above-mentioned embodiment of the invention.

[0104] It should be noted that when calculating the electron content of the ionospheric piercing point, it is necessary to consider that the electron content at each altitude layer will be affected by the ionospheric electron density of the four grid points of the grid where the ionospheric piercing point is located. Each observation value projected perpendicular to the ground at each ionospheric piercing point may be affected by the positive prism electron density.

[0105] In step S201, first determine the grids of all altitude layers in the local direction perpendicular to the ionospheric puncture point to be solved, including: the grid where the ionospheric puncture point itself is located and the grids on other altitude layers overlapping with it on the horizontal plane. Then obtain the corrected ionospheric electron density analysis values ​​of the grid points corresponding to these grids. The grid points corresponding to the grid are the four vertices of the grid.

[0106] S202. Calculate the electron content of the ionospheric puncture point based on all the corrected ionospheric electron density analysis values.

[0107] In a preferred embodiment, the step of calculating the electron content of the ionospheric puncture point based on all the corrected ionospheric electron density analysis values ​​comprises:

[0108] For each altitude layer, a weighted average value of the corrected ionospheric electron density analysis value corresponding to the altitude layer is calculated;

[0109] Summing the weighted average values ​​corresponding to all altitude layers to obtain the electron content of the ionospheric puncture point;

[0110] The calculation formula of the electron content of the ionospheric puncture point is:

[0111]

[0112] Where V B represents the electron content at the ionospheric puncture point; i,j Indicates the longitude of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; φ i,j Indicates the dimension of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; h k Represents the height of the grid point with index k in the height direction of the three-dimensional network; N A (λ i,j ,φ i,j ,h k ) represents the position (λ i,j ,φ i,j ,h k ) ionospheric electron density analysis value; w t,k It represents the weight value of the tth corrected ionospheric electron density analysis value corresponding to the kth altitude layer; K represents the total number of altitude layers; T represents the total number of corrected ionospheric electron density analysis values ​​corresponding to each altitude layer.

[0113] In this embodiment, the layer electron density of each altitude layer is first calculated, that is, the weighted average value of the corrected ionospheric electron density analysis value corresponding to each altitude layer is calculated; then the layer electron density of all altitude layers is summed up to obtain the electron content of the ionospheric puncture point to be solved.

[0114] Embodiment 3

[0115] Please refer to Figure 3 , is a schematic structural diagram of an ionospheric electron density calculation device provided by an embodiment of the present invention, comprising: a first data acquisition module, a data assimilation module and a correction module;

[0116] The first data acquisition module is used to obtain the electron content observation value of the ionospheric puncture point and the ionospheric electron density background value of the three-dimensional network; wherein the three-dimensional regular network is provided by a global empirical model;

[0117] The data assimilation module is used to perform data assimilation according to the electron content observation value and the ionospheric electron density background value to obtain an expression of the ionospheric electron density analysis value; wherein the expression is an expression of the ionospheric electron density with respect to the position variance factor;

[0118] The correction module is used to construct an observation error analysis function according to the expression of the ionospheric electron density analysis value, the electron content observation value and the ionospheric electron density background value; take minimization of the observation error analysis function as the objective function, and solve to obtain the target position variance factor; and calculate the corrected ionospheric electron density analysis value according to the target position variance factor through the expression of the ionospheric electron density analysis value.

[0119] Embodiment 4

[0120] Please refer to Figure 4 , is a schematic diagram of the structure of an electronic content calculation device provided by an embodiment of the present invention, the electronic content calculation device comprises: a second data acquisition module and an electronic content calculation module;

[0121] The second data acquisition module is used to obtain the corrected ionospheric electron density analysis value of the grid points corresponding to the grid where the ionospheric puncture point to be solved is located and the grids on all altitude layers overlapping with the grid where the ionospheric puncture point is located on the horizontal plane; wherein the grid is a grid in a three-dimensional regular network provided by a global empirical model; the grid points are grid points in a three-dimensional regular network provided by the global empirical model; the corrected ionospheric electron density analysis value is calculated according to the electron content calculation method as described in the above-mentioned embodiment of the invention;

[0122] The electron content calculation module is used to calculate the electron content of the ionospheric puncture point based on all the corrected ionospheric electron density analysis values.

[0123] 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.

[0124] 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.

[0125] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

[0126] 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.

[0127] In the description of the embodiments of the present application, technical terms such as "first" and "second" 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.

Claims

1. A method for calculating ionospheric electron density, characterized in that: include: Obtaining the electron content observation value of the ionospheric puncture point and the ionospheric electron density background value of the three-dimensional network; wherein the three-dimensional regular network is provided by a global empirical model; According to the electron content observation value and the ionospheric electron density background value, data assimilation is performed to obtain an expression of the ionospheric electron density analysis value; wherein the expression is an expression of the ionospheric electron density with respect to the position variance factor; Constructing an observation error analysis function according to the expression of the ionospheric electron density analysis value, the electron content observation value and the ionospheric electron density background value; Taking the minimization of the observation error analysis function as the objective function, the variance factor of the target position is obtained by solving; According to the target position variance factor, the corrected ionospheric electron density analysis value is calculated through the expression of the ionospheric electron density analysis value.

2. The ionospheric electron density calculation method according to claim 1, wherein: Before obtaining the electron content observation value of the ionospheric piercing point, it also includes: Acquiring a carrier phase observation value of the ionospheric puncture point by a dual-frequency GNSS receiver; Calculating the electron content observation value of the ionospheric puncture point according to the carrier phase observation value; The calculation formula of the electron content observation value is: Where V R represents the electron content observation value; L represents the carrier phase observation value; f1 and f2 are the signal frequencies used by the dual-frequency receiver; B is the pseudorange hardware delay; SDCB is the dual-frequency code deviation of the satellite; RDCB is the dual-frequency code deviation of the dual-frequency receiver.

3. The ionospheric electron density calculation method according to claim 1, wherein: The performing data assimilation according to the electron content observation value and the ionospheric electron density background value comprises: Taking the latitude and longitude position of the ionospheric puncture point as the reference position, the electron content observation value and the ionospheric electron density background value are assimilated to obtain the following expression of the ionospheric electron density analysis value: N A (l i,j ,f i,j ,h k )=N B (l i,j ,f i,j ,h k )+G(V R (λ0,φ0))-HN B (l i,j ,f i,j ,h k ); i=1...nI, j=1...nJ, k=1...K; G=BH T (R+HBH T ) -1 ; R=P -1 ; B=s B I; In the formula, λ i,j Indicates the longitude of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; φ i,j Indicates the dimension of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; h k Represents the height of the grid point with index k in the height direction of the three-dimensional network; N A (λ i,j ,φ i,j ,h k ) represents the position (λ i,j ,φ i,j ,h k ) ionospheric electron density analysis value; N B (λ i,j ,φ i,j ,h k ) represents the position (λ i,j ,φ i,j ,h k ) is the ionospheric electron density background value at ; nI represents the number of all grids in the longitude direction of the three-dimensional grid; nJ represents the number of all grids in the dimension direction of the three-dimensional grid; K represents the number of all grids in the height direction of the three-dimensional grid; G represents the assimilation weight matrix; λ0 represents the longitude of the reference position; φ0 represents the dimension of the reference position; H represents the observation value submatrix; B represents the observation value coefficient matrix; represents the observation value covariance matrix; P represents the observation value weight matrix; represents random error; σ B represents the position method factor; I is the unit matrix.

4. The ionospheric electron density calculation method according to claim 3, characterized in that: The expression of the observation error analysis function is: f(N A )= ||V R (λ0,φ0)-HN A (l i,j ,f i,j ,h k )||2+||N A (l i,j ,f i,j ,h k )-N B (l i,j ,f i,j ,h k )||; In the formula, f(N A ) represents the observation error analysis function.

5. The ionospheric electron density calculation method according to claim 3, characterized in that: The objective function is to minimize the observation error analysis function and solve the target position variance factor, including: Under the condition that the position variance factor is greater than 0, the objective function is to minimize the observation error analysis function and solve the target position variance factor; Among them, the solution formula of the target position variance factor is:

6. The ionospheric electron density calculation method according to claim 1, characterized in that: The three-dimensional network has a longitude resolution of 0.5°, a latitude resolution of 0.5°, an altitude resolution of 50 kilometers, and an altitude range of 100 kilometers to 2000 kilometers above sea level.

7. A method for calculating electron content, characterized in that: include: Obtain the corrected ionospheric electron density analysis value of the grid points near the ionospheric puncture point to be solved; wherein the grid points near the ionospheric puncture point refer to the grid where the ionospheric puncture point is located and the grid points corresponding to the grids on all altitude layers overlapping with the grid where the ionospheric puncture point is located on the horizontal plane; the grid is a grid in a three-dimensional regular network provided by a global empirical model; the grid points are grid points in a three-dimensional regular network provided by the global empirical model; the corrected ionospheric electron density analysis value is calculated according to any one of claims 1 to 6; The electron content of the ionospheric puncture point is calculated based on all the corrected ionospheric electron density analysis values.

8. The method for calculating the electron content according to claim 7, characterized in that: The step of calculating the electron content of the ionospheric puncture point according to all the corrected ionospheric electron density analysis values ​​comprises: For each altitude layer, a weighted average value of the corrected ionospheric electron density analysis value corresponding to the altitude layer is calculated; Summing the weighted average values ​​corresponding to all altitude layers to obtain the electron content of the ionospheric puncture point; The calculation formula of the electron content of the ionospheric puncture point is: Where V B represents the electron content at the ionospheric puncture point; i,j Indicates the longitude of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; φ i,j Indicates the dimension of the grid point with index i in the longitude direction and index j in the dimensional direction in the three-dimensional network; h k Represents the height of the grid point with index k in the height direction of the three-dimensional network; N A (λ i,j ,φ i,j ,h k ) represents the position (λ i,j ,φ i,j ,h k ) ionospheric electron density analysis value; w t,k It represents the weight value of the tth corrected ionospheric electron density analysis value corresponding to the kth altitude layer; K represents the total number of altitude layers; T represents the total number of corrected ionospheric electron density analysis values ​​corresponding to each altitude layer.

9. An ionospheric electron density calculation device, characterized in that: include: A first data acquisition module, a data assimilation module and a correction module; The first data acquisition module is used to obtain the electron content observation value of the ionospheric puncture point and the ionospheric electron density background value of the three-dimensional network; wherein the three-dimensional regular network is provided by a global empirical model; The data assimilation module is used to perform data assimilation according to the electron content observation value and the ionospheric electron density background value to obtain an expression of the ionospheric electron density analysis value; wherein the expression is an expression of the ionospheric electron density with respect to the position variance factor; The correction module is used to construct an observation error analysis function according to the expression of the ionospheric electron density analysis value, the electron content observation value and the ionospheric electron density background value; take minimization of the observation error analysis function as the objective function, and solve to obtain the target position variance factor; and calculate the corrected ionospheric electron density analysis value according to the target position variance factor through the expression of the ionospheric electron density analysis value.

10. An electronic content calculation device, characterized in that: include: a second data acquisition module and an electron content calculation module; The second data acquisition module is used to obtain the corrected ionospheric electron density analysis value of the grid points corresponding to the grid where the ionospheric puncture point to be solved is located and the grids on all altitude layers overlapping with the grid where the ionospheric puncture point is located on the horizontal plane; wherein the grid is a grid in a three-dimensional regular network provided by a global empirical model; the grid points are grid points in a three-dimensional regular network provided by the global empirical model; the corrected ionospheric electron density analysis value is calculated according to any one of claims 1 to 6; The electron content calculation module is used to calculate the electron content of the ionospheric puncture point based on all the corrected ionospheric electron density analysis values.

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