Ionized layer projection function model construction method and device, equipment and storage medium

Abstract

The invention discloses an ionosphere projection function model construction method and device, equipment and a storage medium. The method comprises the following steps: acquiring historical inclined total electron content data of an ionosphere; taking a historical tilt total electron content value of a satellite elevation angle above a preset angle in the historical tilt total electron content data as a corresponding historical vertical total electron content value, and calculating to obtain a corresponding historical projection function value; acquiring a corresponding simplified Julian day, local time, a satellite elevation angle and an azimuth angle of an ionospheric puncture point; and according to the historical projection function value, the simplified Julian day, the local time, the satellite elevation angle and the azimuth angle of the ionospheric puncture point, taking the simplified Julian day, the local time, the satellite elevation angle and the azimuth angle of the ionospheric puncture point as input, taking the historical projection function value as output, training a preset LSTM model, and obtaining an ionospheric projection function model. According to the invention, the precision of the ionosphere projection function can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of GNSS precision data processing, and in particular to a method, device, equipment and storage medium for constructing an ionospheric projection function model. Background Art

[0002] The ionosphere is an important part of the solar-terrestrial space environment. Monitoring and studying various phenomena in the ionosphere and revealing its temporal and spatial variation laws and physical mechanisms are not only conducive to promoting the research of interdisciplinary subjects in the field of ionosphere theory and earth science, but also conducive to the development of aerospace, aviation and communication applications. Among them, the mapping function (MF) is used to realize the mutual conversion between vertical total electron content (VTEC) and slant total electron content (STEC), which is crucial to the application of ionosphere products.

[0003] In the past few decades, a variety of projection functions have been proposed and widely used. Among them, the most commonly used projection function is the single-layer projection function (MF). Based on the assumption that the electron density of the ionosphere is spherically symmetrical and evenly distributed, this projection function establishes a trigonometric projection relationship between the receiver-to-satellite elevation angle and the ionosphere thin layer height. There is also the Klobuchar MF, which is at a fixed altitude and is only related to the elevation angle from the station to the satellite. In addition, projection functions such as the MSLMF are also widely used. With the rapid development of deep learning technology, the long short-term memory model (LSTM) has also been widely used in ionosphere modeling and prediction. Many scholars have carried out VTEC prediction research based on the LSTM model, and the LSTM model has also performed well in the prediction of solar indices such as the sunspot number and the Kp index, creating good conditions for the construction of projection functions. However, these projection functions only consider the influence of the ionosphere thin layer height and the signal elevation angle, but do not consider the influence of the ionosphere's spatiotemporal changes and azimuth angle, resulting in the low accuracy of the existing ionosphere projection functions. Summary of the invention

[0004] The present invention provides a method, device, equipment and storage medium for constructing an ionospheric projection function model to solve the technical problem that the existing projection functions only consider the influence of the ionospheric thin layer height and the signal elevation angle, but do not consider the influence of the ionospheric spatiotemporal changes and azimuth angle, and the accuracy is not high.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a method for constructing an ionospheric projection function model, comprising:

[0006] Acquire historical tilt total electron content data of the ionosphere; wherein the historical tilt total electron content data includes: historical tilt total electron content value on each ray of the ionosphere;

[0007] Taking the historical tilt total electron content value of the satellite altitude angle above the preset angle in the historical tilt total electron content data as the target historical tilt total electron content value, and taking the target historical tilt total electron content value as the corresponding historical vertical total electron content value, and then calculating the corresponding historical projection function value according to the historical tilt total electron content value and the historical vertical total electron content value;

[0008] Obtaining the simplified Julian day, local time, satellite altitude angle, and azimuth of the ionospheric puncture point corresponding to the historical tilt total electron content data;

[0009] According to the historical projection function value, the simplified Julian day, the local time, the satellite altitude angle and the azimuth of the ionospheric piercing point, a preset LSTM model is trained with the simplified Julian day, the local time, the satellite altitude angle and the azimuth of the ionospheric piercing point as input and the corresponding historical projection function value as output to obtain a corresponding ionospheric projection function model.

[0010] As a preferred solution, the method for constructing the ionospheric projection function model further includes:

[0011] Acquire current tilt total electron content data, and acquire the corresponding simplified Julian day, local time, satellite altitude angle, and azimuth of the ionospheric puncture point according to the current tilt total electron content data;

[0012] The simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point corresponding to the current tilted total electron content data are input into the ionospheric projection function model, so that the ionospheric projection function model calculates the current ionospheric projection function corresponding to the current tilted total electron content data according to the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point corresponding to the current tilted total electron content data, and outputs the corresponding current ionospheric projection function.

[0013] As a preferred solution, before taking the historical tilt total electron content value of the satellite altitude angle above the preset angle in the historical tilt total electron content data as the target historical tilt total electron content value, the method further includes:

[0014] The historical tilted total electron content data is preprocessed; wherein the preprocessing includes: data downsampling processing.

[0015] As a preferred solution, the local time is calculated by the following formula:

[0016]

[0017] where h, m, and s are the hours, minutes, and seconds corresponding to the historical tilted total electron content data, respectively, and λ IPP is the longitude of the ionospheric piercing point.

[0018] As a preferred solution, the LSTM model includes: an input layer, a hidden layer, a fully connected layer and an output layer;

[0019] Among them, the input features of the input layer are simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point; the hidden layer includes two LSTM layers; the fully connected layer performs a linear transformation on the output of the output layer, and outputs the result of the linear transformation to the output layer.

[0020] As a preferred solution, the corresponding historical projection function value is calculated according to the following formula:

[0021] MF=VTEC / STEC;

[0022] Among them, MF is the historical projection function value, VTEC is the historical vertical total electron content value, and STEC is the historical inclined vertical total electron content value.

[0023] As a preferred solution, the method for constructing the ionospheric projection function model further includes:

[0024] Inputting the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric puncture point corresponding to the historical tilted total electron content data into the ionospheric projection function model, so that the ionospheric projection function model calculates the corresponding projection function value according to the input simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric puncture point, and outputs the corresponding first historical projection function value;

[0025] Calculating a corresponding first historical vertical total electron content value according to the first historical projection function value and the historical tilted total electron content;

[0026] Performing interpolation processing on the first historical vertical total electron content value, and then calculating the corresponding first historical inclined total electron content value according to the interpolated first historical vertical total electron content value and the first historical projection function value;

[0027] The accuracy of the ionospheric projection function model is verified based on the first historical tilt total electron content value.

[0028] On the basis of the above embodiment, another embodiment of the present invention provides a device for constructing an ionospheric projection function model, comprising: a first data acquisition module, a projection function value calculation module, a second data acquisition module and an ionospheric projection function model construction module;

[0029] The first data acquisition module is used to acquire the historical tilt total electron content data of the ionosphere; wherein the historical tilt total electron content data includes: the historical tilt total electron content value on each ray of the ionosphere;

[0030] The projection function value calculation module is used to use the historical tilt total electron content value of the satellite altitude angle above the preset angle in the historical tilt total electron content data as the target historical tilt total electron content value, and use the target historical tilt total electron content value as the corresponding historical vertical total electron content value, and then calculate the corresponding historical projection function value according to the historical tilt total electron content value and the historical vertical total electron content value;

[0031] The second data acquisition module is used to obtain the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric puncture point corresponding to the historical tilt total electron content data;

[0032] The ionospheric projection function model construction module is used to train a preset LSTM model based on the historical projection function value, simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point, with the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point as input and the corresponding historical projection function value as output to obtain the corresponding ionospheric projection function model.

[0033] Based on the above embodiments, another 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 method for constructing the ionospheric projection function model described in the above embodiments of the invention when executing the computer program.

[0034] 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 method for constructing the ionospheric projection function model described in the above invention embodiment.

[0035] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0036] The present invention provides a method for constructing an ionospheric projection function model, which includes obtaining historical tilt total electron content data of the ionosphere; taking a historical tilt total electron content value of a satellite altitude angle above a preset angle in the historical tilt total electron content data as a target historical tilt total electron content value, and taking the target historical tilt total electron content value as a corresponding historical vertical total electron content value, and then calculating a corresponding historical projection function value according to the historical tilt total electron content value and the historical vertical total electron content value; obtaining a simplified Julian day, local time, satellite altitude angle, and azimuth of an ionospheric puncture point corresponding to the historical tilt total electron content data; and according to the historical projection function value, the simplified Julian day, local time, satellite altitude angle, and azimuth of an ionospheric puncture point, taking the simplified Julian day, local time, satellite altitude angle, and azimuth of an ionospheric puncture point as input, and taking the corresponding historical projection function value as output, training a preset LSTM model to obtain a corresponding ionospheric projection function model. The present invention uses the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric puncture point as input, takes the projection function value corresponding to the historical tilt total electron content data as output, trains the LSTM model, and finally obtains the corresponding ionospheric projection function model. Since the input parameters use the simplified Julian day, local time and azimuth, the influence of the spatiotemporal changes of the ionosphere and the azimuth is taken into account, and the accuracy of the ionospheric projection function can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flow chart of a method for constructing an ionospheric projection function model provided by one embodiment of the present invention;

[0038] Figure 2 It is a structural diagram of the LSTM model of the present invention;

[0039] Figure 3 It is a structural schematic diagram of a device for constructing an ionospheric projection function model provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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).

[0046] 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.

[0047] Embodiment 1

[0048] Please refer to Figure 1, is a flow chart of a method for constructing an ionospheric projection function model provided by an embodiment of the present invention, comprising the following specific steps:

[0049] S1. Acquire historical tilt total electron content data of the ionosphere; wherein the historical tilt total electron content data includes: historical tilt total electron content value on each ray of the ionosphere;

[0050] Preferably, before taking the historical tilt total electron content value in the historical tilt total electron content data with a satellite elevation angle above a preset angle as the target historical tilt total electron content value, it also includes: preprocessing the historical tilt total electron content data; wherein the preprocessing includes: data downsampling processing.

[0051] Specifically, the method for constructing the ionospheric projection function model of the present invention comprises the following steps:

[0052] 1. Data acquisition and preprocessing:

[0053] The historical slant total electron content (STEC) products provided by the MIT / Haystack Observatory platform were collected in advance, and the data were downsampled to reduce the time resolution to 10 minutes; wherein the STEC product is the STEC value on each ray, and the product website is http: / / cedar.openmadr i gal.org / sign le / .

[0054] S2, taking the historical tilt total electron content value of the satellite altitude angle above the preset angle in the historical tilt total electron content data as the target historical tilt total electron content value, and taking the target historical tilt total electron content value as the corresponding historical vertical total electron content value, and then calculating the corresponding historical projection function value according to the historical tilt total electron content value and the historical vertical total electron content value;

[0055] Preferably, the corresponding historical projection function value is calculated according to the following formula:

[0056] MF=VTEC / STEC;

[0057] Among them, MF is the historical projection function value, VTEC is the historical vertical total electron content value, and STEC is the historical inclined vertical total electron content value.

[0058] 2. Generation of training samples:

[0059] (a) First, we select the STEC data with satellite elevation angles above 85° and regard them as VTEC values, because according to the SLMF function:

[0060]

[0061] In the formula, R represents the radius of the earth, H represents the height of the ionosphere thin layer, and E is the satellite altitude angle. When the thin layer height is selected as 350km and the satellite altitude angle is 85°, the value of SLMF is 0.9966, and the difference between STEC and VTEC can be ignored;

[0062] (b) Select rays whose time interval with VTEC in (a) is no more than 5 minutes and whose longitude and latitude are no more than 0.5° from the ionospheric pierce point (IPP). Specify a cutoff elevation angle of 20° to obtain STEC corresponding to VTEC;

[0063] (c) Calculate the projection function value: MF = VTEC / STEC.

[0064] S3, obtaining the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric puncture point corresponding to the historical tilt total electron content data;

[0065] Preferably, the local time is calculated by the following formula:

[0066]

[0067] where h, m, and s are the hours, minutes, and seconds corresponding to the historical tilted total electron content data, respectively, and λ IPP is the longitude of the ionospheric piercing point.

[0068] (d) The input features selected by the mapping function (MF) model in the present invention are the Modified Julian Day (MJD), local time (LT), satellite altitude angle and azimuth of IPP, and the output is the MF value, where LT is calculated as follows:

[0069]

[0070] Among them, h, m and s represent the hour, minute and second of the data respectively, λ IPP Represents the longitude of the IPP.

[0071] The elevation angle of IPP can be calculated by the following formula:

[0072]

[0073] S4. According to the historical projection function value, the simplified Julian day, the local time, the satellite altitude angle, and the azimuth of the ionospheric piercing point, a preset LSTM model is trained with the simplified Julian day, the local time, the satellite altitude angle, and the azimuth of the ionospheric piercing point as input and the corresponding historical projection function value as output to obtain a corresponding ionospheric projection function model.

[0074] Preferably, the LSTM model includes: an input layer, a hidden layer, a fully connected layer and an output layer; wherein the input features of the input layer are the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point; the hidden layer includes two LSTM layers; the fully connected layer performs a linear transformation on the output of the output layer, and outputs the result of the linear transformation to the output layer.

[0075] 3. Construction of ionospheric projection function model:

[0076] Recurrent neural network (RNN) is a deep learning model with memory function, which can remember the previous time series and add it to the output calculation. It is widely used in time series prediction. LSTM is an RNN architecture used to model time series and long-term dependencies. Compared with RNN, it has stronger learning and information selection capabilities. Please refer to Figure 2 , which is a structural diagram of the LSTM model used in the present invention. The model includes four layers: input layer, hidden layer, fully connected layer and output layer. The input layer uses MJD, LT, elevation and azimuth of IPP as input features, and the hidden layer includes two LSTM layers. The LSTM layer outputs the result to the fully connected layer, and the fully connected layer performs a linear transformation on the output layer; finally, the corresponding MF value is output as a label.

[0077] Then, the projection function value, simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point are used as training samples of the LSTM model. The simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point are used as input, and the corresponding projection function value is used as output. A preset LSTM model is trained to obtain a corresponding ionospheric projection function model.

[0078] Preferably, the method for constructing the ionospheric projection function model also includes: inputting the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point corresponding to the historical tilted total electron content data into the ionospheric projection function model, so that the ionospheric projection function model calculates the corresponding projection function value according to the input simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point, and outputs the corresponding first historical projection function value; calculating the corresponding first historical vertical total electron content value according to the first historical projection function value and the historical tilted total electron content; interpolating the first historical vertical total electron content value, and then calculating the corresponding first historical tilted total electron content value according to the interpolated first historical vertical total electron content value and the first historical projection function value; verifying the accuracy of the ionospheric projection function model according to the first historical tilted total electron content value.

[0079] Preferably, the method for constructing the ionospheric projection function model also includes: obtaining current tilted total electron content data, and obtaining the corresponding simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point based on the current tilted total electron content data; inputting the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point corresponding to the current tilted total electron content data into the ionospheric projection function model, so that the ionospheric projection function model calculates the current ionospheric projection function corresponding to the current tilted total electron content data based on the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point corresponding to the current tilted total electron content data, and outputs the corresponding current ionospheric projection function.

[0080] 4. Model Validation:

[0081] Ionospheric grid product generation: Ionospheric products are usually published in grid form for ease of use. In the process of constructing the ionospheric projection function model, STEC with an elevation angle greater than 85° is used as VTEC, and STEC data with a time interval with VTEC of no more than 5 minutes and an IPP longitude and latitude of no more than 0.5° are selected. In the training samples of the present invention, a total of 40% of the data were not used for training, 20% were used to generate VTEC, and 20% were used to verify VTEC. The 20% STEC data that was not used in LSTM model training, verification and testing was interpolated to obtain an ionospheric grid product VTEC model with a spatial resolution of 1°×1° and a time resolution of 10 minutes, and another 20% of STEC data was used to verify the accuracy of the ionospheric grid product. Specifically:

[0082] The simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point are input into the ionospheric projection function model, so that the ionospheric projection function model calculates the projection function value according to the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point, and outputs the corresponding first projection function value; calculates the corresponding first inclined total electron content value according to the first projection function value and the vertical total electron content; interpolates the first inclined total electron content value, and then calculates the corresponding first vertical total electron content value according to the interpolated first inclined total electron content value and the first projection function value; verifies the accuracy of the ionospheric projection function model according to the first vertical total electron content value.

[0083] 5. VTEC product release:

[0084] (a) 20% of the STEC data that were not used for training, validation, and testing the LSTM-MF model were selected for the production of VTEC products. The MJD, LT, elevation, and azimuth of the IPP corresponding to these STEC data were input into the LSTM-MF model, and the model output the MF value;

[0085] (b) Calculate VTEC data based on the STEC data and MF value in (a), and interpolate to obtain the Model 1 VTEC product;

[0086] (c) Another 20% of the STEC data that was not used for training, validating, and testing the LSTM-MF model was selected to validate the VTEC model product. The VTEC at a certain point was interpolated based on the model VTEC product, and the VTEC was projected onto the STEC using the MF value output by the LSTMMF model, and the STEC accuracy obtained from the model VTEC product was evaluated.

[0087] 6. Application of ionospheric projection function model

[0088] The current tilted total electron content data is obtained, and the corresponding simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point are obtained according to the current tilted total electron content data; the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point corresponding to the current tilted total electron content data are input into the ionospheric projection function model, so that the ionospheric projection function model calculates the current ionospheric projection function corresponding to the current tilted total electron content data according to the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point corresponding to the current tilted total electron content data, and outputs the corresponding current ionospheric projection function.

[0089] Embodiment 2

[0090] Please refer to Figure 3 , is a schematic diagram of the structure of a device for constructing an ionospheric projection function model provided by an embodiment of the present invention, the device comprising: a first data acquisition module, a projection function value calculation module, a second data acquisition module and an ionospheric projection function model construction module;

[0091] The first data acquisition module is used to acquire the historical tilt total electron content data of the ionosphere; wherein the historical tilt total electron content data includes: the historical tilt total electron content value on each ray of the ionosphere;

[0092] The projection function value calculation module is used to use the historical tilt total electron content value of the satellite altitude angle above the preset angle in the historical tilt total electron content data as the target historical tilt total electron content value, and use the target historical tilt total electron content value as the corresponding historical vertical total electron content value, and then calculate the corresponding historical projection function value according to the historical tilt total electron content value and the historical vertical total electron content value;

[0093] The second data acquisition module is used to obtain the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric puncture point corresponding to the historical tilt total electron content data;

[0094] The ionospheric projection function model construction module is used to train a preset LSTM model based on the historical projection function value, simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point, with the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point as input and the corresponding historical projection function value as output to obtain the corresponding ionospheric projection function model.

[0095] 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.

[0096] 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.

[0097] Embodiment 3

[0098] 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 method for constructing the ionospheric projection function model described in the above-mentioned embodiment of the invention when executing the computer program.

[0099] 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.

[0100] 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.

[0101] Embodiment 4

[0102] 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 method for constructing the ionospheric projection function model described in the above-mentioned embodiment of the invention.

[0103] 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 Med ia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0104] 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-On l yMemory), 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.

[0105] 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. A method for constructing an ionospheric projection function model, characterized in that: include: Acquire historical tilt total electron content data of the ionosphere; wherein the historical tilt total electron content data includes: historical tilt total electron content value on each ray of the ionosphere; Taking the historical tilt total electron content value of the satellite altitude angle above the preset angle in the historical tilt total electron content data as the target historical tilt total electron content value, and taking the target historical tilt total electron content value as the corresponding historical vertical total electron content value, and then calculating the corresponding historical projection function value according to the historical tilt total electron content value and the historical vertical total electron content value; Obtaining the simplified Julian day, local time, satellite altitude angle, and azimuth of the ionospheric puncture point corresponding to the historical tilt total electron content data; According to the historical projection function value, the simplified Julian day, the local time, the satellite altitude angle and the azimuth of the ionospheric piercing point, a preset LSTM model is trained with the simplified Julian day, the local time, the satellite altitude angle and the azimuth of the ionospheric piercing point as input and the corresponding historical projection function value as output to obtain a corresponding ionospheric projection function model.

2. The method for constructing the ionospheric projection function model according to claim 1, wherein: Also includes: Acquire current tilt total electron content data, and acquire the corresponding simplified Julian day, local time, satellite altitude angle, and azimuth of the ionospheric puncture point according to the current tilt total electron content data; The simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point corresponding to the current tilted total electron content data are input into the ionospheric projection function model, so that the ionospheric projection function model calculates the current ionospheric projection function corresponding to the current tilted total electron content data according to the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point corresponding to the current tilted total electron content data, and outputs the corresponding current ionospheric projection function.

3. The method for constructing the ionospheric projection function model according to claim 1, wherein: Before taking the historical tilt total electron content value of the satellite elevation angle above the preset angle in the historical tilt total electron content data as the target historical tilt total electron content value, the method further includes: The historical tilted total electron content data is preprocessed; wherein the preprocessing includes: data downsampling processing.

4. The method for constructing the ionospheric projection function model according to claim 3, wherein: The local time is calculated by the following formula: where h, m, and s are the hours, minutes, and seconds corresponding to the historical tilted total electron content data, respectively, and λ IPP is the longitude of the ionospheric piercing point.

5. The method for constructing the ionospheric projection function model according to claim 1, wherein: The LSTM model includes: an input layer, a hidden layer, a fully connected layer and an output layer; Among them, the input features of the input layer are simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point; the hidden layer includes two LSTM layers; the fully connected layer performs a linear transformation on the output of the output layer, and outputs the result of the linear transformation to the output layer.

6. The method for constructing the ionospheric projection function model according to claim 1, wherein: According to the following formula, the corresponding historical projection function value is calculated: MF=VTEC / STEC; Among them, MF is the historical projection function value, VTEC is the historical vertical total electron content value, and STEC is the historical inclined vertical total electron content value.

7. The method for constructing the ionospheric projection function model according to claim 1, wherein: Also includes: Inputting the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric puncture point corresponding to the historical tilted total electron content data into the ionospheric projection function model, so that the ionospheric projection function model calculates the corresponding projection function value according to the input simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric puncture point, and outputs the corresponding first historical projection function value; Calculating a corresponding first historical vertical total electron content value according to the first historical projection function value and the historical tilted total electron content; Performing interpolation processing on the first historical vertical total electron content value, and then calculating the corresponding first historical inclined total electron content value according to the interpolated first historical vertical total electron content value and the first historical projection function value; The accuracy of the ionospheric projection function model is verified based on the first historical tilt total electron content value.

8. A device for constructing an ionospheric projection function model, characterized in that: include: A first data acquisition module, a projection function value calculation module, a second data acquisition module and an ionospheric projection function model construction module; The first data acquisition module is used to acquire the historical tilt total electron content data of the ionosphere; wherein the historical tilt total electron content data includes: the historical tilt total electron content value on each ray of the ionosphere; The projection function value calculation module is used to use the historical tilt total electron content value of the satellite altitude angle above the preset angle in the historical tilt total electron content data as the target historical tilt total electron content value, and use the target historical tilt total electron content value as the corresponding historical vertical total electron content value, and then calculate the corresponding historical projection function value according to the historical tilt total electron content value and the historical vertical total electron content value; The second data acquisition module is used to obtain the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric puncture point corresponding to the historical tilt total electron content data; The ionospheric projection function model construction module is used to train a preset LSTM model based on the historical projection function value, simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point, with the simplified Julian day, local time, satellite altitude angle and azimuth of the ionospheric piercing point as input and the corresponding historical projection function value as output to obtain the corresponding ionospheric projection function model.

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 when the processor executes the computer program, the method for constructing the ionospheric projection function model as described in any one of claims 1 to 7 is implemented.

10. A storage medium, characterized in that: 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 method for constructing the ionospheric projection function model as described in any one of claims 1 to 7.

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