Ionosphere total electron content projection method considering ionosphere thickness and inclination

Abstract

The application discloses an ionosphere total electron content projection method considering ionosphere thickness and inclination, and comprises the following steps: converting the geodetic coordinates of a receiver and a satellite into the geocentric coordinates; discretizing the line connecting the receiver and the satellite into a series of discrete points, and obtaining the geodetic coordinates of each discrete point; based on the electron density around the discrete points, interpolating the electron density at the discrete points, and integrating the electron density at the discrete points to obtain the slant electron content; calculating the longitude and latitude of the piercing point and the two points adjacent to the piercing point, and calculating the distances from the receiver, the satellite, the piercing point and the two points adjacent to the piercing point to the earth equator; according to the distances from the receiver, the satellite, the piercing point and the two points adjacent to the piercing point to the earth equator, and in combination with the geodetic heights of the receiver, the satellite and the two points adjacent to the piercing point, the inclination of the line connecting the receiver and the satellite on the ground and the inclination of the ionosphere are calculated; and the ionosphere total electron content is calculated.

Description

Technical Field

[0001] This invention relates to the field of total electron content in the ionosphere, particularly to the field of total electron content projection in the ionosphere, specifically a method for projecting total electron content in the ionosphere that takes into account the thickness and tilt angle of the ionosphere. Background Technology

[0002] Total Electron Content (TEC) is an important parameter in space weather research, and it has a significant impact on a range of fields such as satellite navigation, meteorology, and communications. Therefore, obtaining a more accurate TEC is particularly important.

[0003] The most commonly used method for projecting the ionospheric TEC between satellites and receivers is as follows: In the thin ionospheric layer, all the ionospheric TEC along the line of sight is compressed onto the ionospheric puncture point, and represented by the ionospheric TEC perpendicular to that point, i.e., Vertical TEC (VTEC). In actual calculations, the total electron content of the ionosphere along the inclined path between the satellite and receiver is first obtained, i.e., Slant TEC (STEC), and then the STEC is converted to VTEC using a trigonometric projection function, thus obtaining the ionospheric VTEC between the satellite and receiver. However, this method ignores the thickness of the ionosphere itself and the angle between the ionosphere and the ground, resulting in an inaccurate ionospheric VTEC with a large discrepancy from the true ionospheric VTEC, which has a significant impact on ionospheric correction in satellite navigation, communication and other fields.

[0004] It should be noted that TIEGCM (Thermosphere Ionosphere Electrodynamics General Circulation Model) is a model used to simulate the dynamics of the thermosphere and ionosphere. This model can simulate the physical and chemical processes of the Earth's upper atmosphere, including parameters such as temperature, density, wind field, and electric field of the thermosphere and ionosphere. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides a projection method for the total electron content of the ionosphere that considers the thickness and tilt angle of the ionosphere. By taking into account the thickness of the ionosphere itself and the angle between it and the ground, a new and more rigorous projection method is obtained, thereby improving the accuracy of the projection results and providing better initial data for ionospheric correction in fields such as satellite navigation and communication.

[0006] According to one aspect of the present invention, a method for projecting the total electron content of the ionosphere, taking into account the ionospheric thickness and tilt angle, is provided, comprising:

[0007] Convert the geodetic coordinates of the receiver and satellite to geocentric and geofixed coordinates;

[0008] In the geocentric coordinate system, the line connecting the receiver and the satellite is discretized into a series of discrete points, and the geodetic coordinates of each discrete point are obtained by transformation.

[0009] Based on the electron density around the discrete point, the electron density at the discrete point is obtained by interpolation, and the electron density at the discrete point is integrated to obtain the oblique electron content.

[0010] Calculate the latitude and longitude of the puncture point and two adjacent points, and calculate the distances from the receiver, satellite, and two adjacent points to the Earth's equator.

[0011] Based on the distances from the receiver, satellite, and two points adjacent to the puncture point to the Earth's equator, and combined with the Earth's altitude at the receiver, satellite, and two points adjacent to the puncture point, calculate the inclination angle of the line connecting the receiver and satellite on the ground and the inclination angle of the ionosphere.

[0012] The total electron content of the ionosphere is calculated by using the tilt angle of the line connecting the receiver and the satellite on the ground and the tilt angle of the ionosphere, combined with the oblique electron content obtained by integration.

[0013] As a further technical solution, the electron density at the discrete point is obtained by interpolation based on the electron density around the discrete point, including:

[0014] Using a linear interpolation method based on triangulation, the electron density at discrete points is obtained by interpolation.

[0015] As a further technical solution, after obtaining the electron density at discrete points, the following is also included:

[0016] The electron density at discrete points is integrated using the trapezoidal numerical integration method to obtain the oblique electron content.

[0017] As a further technical solution, the latitude and longitude of the puncture point and two adjacent points are calculated, including:

[0018] Calculate the azimuth and elevation angles of the satellite relative to the receiver;

[0019] Based on the calculated elevation angle, the zenith angle at the receiver is calculated, and then the zenith angle at the puncture point is calculated.

[0020] Calculate the geocentric angle from the receiver to the puncture point based on the zenith angle at the receiver and the puncture point.

[0021] Based on the calculated geocentric angle, combined with the azimuth angle and the latitude and longitude of the receiver, the latitude and longitude of the puncture point are calculated.

[0022] Add a preset angle to the latitude of the puncture point and subtract a preset angle to obtain the latitude and longitude of two points adjacent to the puncture point.

[0023] As a further technical solution, the tilt angle of the connection between the receiver and the satellite on the ground and the tilt angle of the ionosphere are calculated as follows:

[0024] ,

[0025] in, These represent the tilt angles of the line connecting the receiver and the satellite on the ground and the tilt angle of the ionosphere, respectively. These represent the ground elevations at the receiver, satellite, and two points adjacent to the puncture point, respectively. These represent the distances from the receiver, the satellite, and two points adjacent to the puncture point to the Earth's equator.

[0026] As a further technical solution, the total electron content of the ionosphere was calculated to be:

[0027] ,

[0028] STEC represents the oblique electron content.

[0029] According to one aspect of the present invention, a projection system for the total electron content of the ionosphere, taking into account the ionospheric thickness and tilt angle, is provided for implementing the method, comprising:

[0030] The first main module is used to convert the geodetic coordinates of the receiver and satellite into geocentric and geofixed coordinates.

[0031] The second main module is used to discretize the connection between the receiver and the satellite into a series of discrete points in the geocentric coordinate system, and then convert them to obtain the geodetic coordinates of each discrete point.

[0032] The third main module is used to interpolate the electron density at the discrete point based on the electron density around the discrete point, and to integrate the electron density at the discrete point to obtain the oblique electron content.

[0033] The fourth main module is used to calculate the latitude and longitude of the puncture point and two adjacent points, and to calculate the distances from the receiver, satellite, and two adjacent points to the Earth's equator.

[0034] The fifth main module is used to calculate the tilt angle of the line connecting the receiver and the satellite on the ground and the tilt angle of the ionosphere based on the distances from the receiver, the satellite, and two points adjacent to the puncture point to the Earth's equator, combined with the ground height of the receiver, the satellite, and the two points adjacent to the puncture point.

[0035] The sixth main module is used to calculate the total electron content of the ionosphere based on the tilt angle of the connection between the receiver and the satellite on the ground and the tilt angle of the ionosphere, combined with the oblique electron content obtained by integration.

[0036] According to one aspect of the present invention, an ionospheric total electron content projection device considering ionospheric thickness and tilt angle is provided, comprising a memory and a processor, wherein the memory stores program instructions that are executed by the processor, and the processor invokes the program instructions to execute the ionospheric total electron content projection method considering ionospheric thickness and tilt angle.

[0037] According to one aspect of the present invention, a non-transitory computer-readable storage medium is provided, the non-transitory computer-readable storage medium storing computer instructions that cause the computer to perform the described method for projecting the total electron content of the ionosphere, taking into account the ionospheric thickness and tilt angle.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] This invention, when projecting the total electron content of the ionosphere between a satellite and a receiver, takes into account the thickness of the ionosphere itself and the angle between the ionosphere and the ground. This results in a novel triangle formed by the oblique electron content (STEC), the vertical electron content (VTEC), and the ionosphere itself, within which VTEC is calculated. By considering the thickness of the ionosphere and its angle with the ground, the projection method of this invention is more rigorous, and the calculation results obtained using this method are closer to the true values, thus providing better initial data for ionospheric correction. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart illustrating a method for projecting the total electron content of the ionosphere, taking into account the thickness and tilt angle, as provided in an embodiment of the present invention.

[0042] Figure 2 A schematic diagram illustrating the final calculation of the vertical electron content (VTEC) provided for an embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram showing the difference between the improved projection method and the original projection method provided in an embodiment of the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, the technical features of the various embodiments or individual embodiments provided by the present invention can be arbitrarily combined to form new technical solutions. Such combinations are not bound by the order of steps and / or structural composition patterns, but must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0045] This invention provides a projection method for the total electron content of the ionosphere that takes into account the thickness and tilt angle of the ionosphere. By taking into account the thickness of the ionosphere itself and the angle between it and the ground, a new and more rigorous projection method is obtained, which improves the accuracy of the projection results.

[0046] Please refer to the detailed process of the method provided in the embodiments of this invention. Figure 1 .

[0047] First, define the geodetic coordinates of the satellite and the receiver, respectively. , ,in These represent the latitude of the receiver and the latitude of the satellite, respectively. These represent the receiver longitude and the satellite longitude, respectively. These represent the receiver altitude and satellite altitude, respectively. Next, the geodetic coordinates of the receiver and satellite are converted to coordinates in the Earth-centered Earth-fixed system, using the following formula:

[0048]

[0049] in This indicates the receiver's coordinates in the Earth-centered Earth-fixed system. The eccentricity of the WGS84 reference ellipsoid is a constant; N is the radius of the prime mover circle, which is calculated using the following formula:

[0050]

[0051] In the formula, This is the semi-major axis of the WGS84 ellipsoid. Similarly, the satellite's coordinates in the Earth-centered Earth-fixed system... It can also be obtained from equations (1) and (2).

[0052] Once the coordinates of the receiver and satellite in the Earth-centered Earth-fixed system are obtained, the satellite and receiver can be connected at an appropriate distance. (this spacing) Generally, a distance of 5000m to 10000m is used to discretize the connecting line into a series of points, and the geocentric and geofixed coordinates of these discrete points are obtained, as follows:

[0053] Vectorize the connection between the receiver and the satellite:

[0054]

[0055] The distance from the receiver to the satellite is then a vector. The modulus length, i.e.

[0056]

[0057] Calculate the number of discrete points:

[0058]

[0059] Finally, the coordinates of the discrete points are obtained:

[0060]

[0061] in Indicates the first The geocentric coordinates of a discrete point.

[0062] Next, the geocentric coordinates of the discrete points are converted to geodetic coordinates, as follows:

[0063]

[0064] in, Indicates the first The geodetic coordinates of a discrete point.

[0065] After obtaining the geodetic coordinates of the discrete points, since these points are not necessarily located on a regular grid, the electron density at the discrete points can be obtained by interpolating the ionospheric electron density around them using a linear interpolation method based on triangulation. The electron density data used here is derived from the electron density data in the TIEGCM model. Simultaneously, the electron density at the discrete points is integrated using the trapezoidal numerical integration method to obtain the STEC (Standard Electron Concentration of Electrons). The trapezoidal numerical integration method is detailed below:

[0066]

[0067] In the formula, Indicates the first The and the first Ionospheric electron density at discrete points For the first The and the first The distance from a discrete point to the receiver.

[0068] Next, the tilt angle between the ionosphere and the ground is calculated. To obtain this tilt angle, the intersection of the line connecting the receiver and the satellite with the ionosphere, i.e., the longitude and latitude of the puncture point, must first be calculated, as follows:

[0069] S1. Calculate the azimuth angle A and elevation angle E of the satellite relative to the receiver:

[0070] To calculate the azimuth and elevation angles of the satellite relative to the receiver, the geocentric and earth-fixed coordinate vectors of the satellite and receiver must first be converted into coordinate vectors in the northeast-sky coordinate system centered at the receiver. The rotation matrix between the two is as follows:

[0071]

[0072] The coordinate vector obtained in the East-North coordinate system is:

[0073]

[0074] in Indicates the component of the direction of motion. Indicates the north component. Indicates the celestial component. Let the vector from the receiver to the satellite obtained above be the vector. The specific format is as follows:

[0075]

[0076] The final azimuth angle A and elevation angle E of the satellite relative to the receiver are as follows:

[0077]

[0078] S2. Calculate the zenith angle Z at the receiver:

[0079]

[0080] S3. Calculate the zenith angle at the puncture point using the spherical trigonometry formula and the law of sines:

[0081]

[0082] In the formula, That is, the zenith angle at the puncture point. For the Earth's radius, The statistical height of the ionosphere. This is an empirical coefficient.

[0083] S4. Calculate the geocentric angle from the receiver to the puncture point:

[0084]

[0085] S5. Calculate the longitude and latitude at the puncture point:

[0086]

[0087] After obtaining the longitude and latitude of the puncture point, add 2° to the latitude of the puncture point and subtract 2° from the latitude of the puncture point to obtain the two adjacent points. latitude and longitude At the same time, Geodetic coordinates and ,in The peak electron density height in the TIEGCM model is used as the geodetic height for these two points, which are then used to calculate the ionospheric dip angle. Next, the meridian arc length formula is used to calculate these two points, as well as the distances from the receiver and satellite to the Earth's equator:

[0088]

[0089] In the formula, The semi-major axis of the WGS84 ellipsoid. This represents the eccentricity of the WGS84 reference ellipsoid, where B is the geodetic latitude of the calculation point. The coefficients for the meridian arc length formula are as follows:

[0090]

[0091] Once the distances from each point to the Earth's equator are obtained, the tilt angle of the line connecting the receiver and the satellite on the ground, as well as the tilt angle of the ionosphere, can be calculated.

[0092]

[0093] In the formula, These represent the tilt angles of the line connecting the receiver and the satellite on the ground and the tilt angle of the ionosphere, respectively. These refer to the ground elevations at the receiver, satellite, and two points adjacent to the puncture point mentioned above. The distances from the Earth's equator to the receiver, satellite, and two points adjacent to the puncture point, calculated according to formula (17).

[0094] With the receiver and satellite connection established, and considering the inclination of the ground and the ionosphere, refer to... Figure 2 Then the final ionospheric electron content VTEC can be calculated, as follows:

[0095]

[0096] In the formula, STEC is the oblique electron content STEC obtained by integrating the electron density at discrete points as described above.

[0097] A comparative experiment was conducted between the improved method provided by this invention and the original method. In the experiment, the latitude span of the station was from 15°N to 50°N, and the longitude span was from 80°E to 150°E. The latitude of the satellite was offset northward by 10° relative to the latitude of the station, that is, from 25°N to 60°N. The longitude span was consistent with that of the station, with a latitude span interval of 0.5° and a longitude span interval of 1°. The results calculated by the original method and the improved method are shown in Tables 1 and 2. The original method is the original projection method, and the improved method is the projection method proposed in this invention.

[0098] Table 1 Calculation results of the original method

[0099] ,

[0100] ,

[0101] ,

[0102] .

[0103] Table 2 Calculation results of the method of the present invention

[0104] ,

[0105] ,

[0106] ,

[0107] .

[0108] The first column in the two tables above is the oblique electron content STEC calculated using the corresponding algorithm, the second column is the calculated vertical electron content VTEC, the third column is the TEC in the observation data, and the fourth column is the absolute value of the difference between the second and third columns. Since the original method and the improved method use different projection methods, the positions of the puncture points obtained will be different, resulting in differences in the observation data. As can be seen from the results in the tables, the difference in the improved method is smaller than the difference in the original method. This indicates that the calculation results of the projection method of this invention are closer to the observed values. Therefore, it can be considered that the projection effect is better and the initial value obtained is better. Figure 3 A line graph showing the difference calculated by the two projection methods.

[0109] The implementation of the various embodiments of the present invention is based on programmed processing by a device with processor functionality. Therefore, in practical engineering, the technical solutions and functions of the various embodiments of the present invention are encapsulated into various modules. Based on this reality, and building upon the above embodiments, the embodiments of the present invention provide an ionospheric total electron content projection system that considers ionospheric thickness and tilt angle. This system is used to execute the ionospheric total electron content projection method considering ionospheric thickness and tilt angle in the above method embodiments.

[0110] The system includes: a first main module for converting the geodetic coordinates of the receiver and satellite to geocentric-geocentric coordinates; a second main module for discretizing the line connecting the receiver and satellite into a series of discrete points in the geocentric-geocentric coordinate system and converting each discrete point to its geodetic coordinates; a third main module for interpolating the electron density at the discrete point based on the electron density around the discrete point and integrating the electron density at the discrete point to obtain the oblique electron content; a fourth main module for calculating the latitude and longitude of the puncture point and two adjacent points, and calculating the distances from the receiver, satellite, and two adjacent points to the Earth's equator; a fifth main module for calculating the dip angle of the line connecting the receiver and satellite on the ground and the dip angle of the ionosphere based on the distances from the receiver, satellite, and two adjacent points to the Earth's equator, combined with the geodetic height of the receiver, satellite, and two adjacent points; and a sixth main module for calculating the total electron content of the ionosphere based on the dip angle of the line connecting the receiver and satellite on the ground and the dip angle of the ionosphere, combined with the integrated oblique electron content.

[0111] This invention provides an ionospheric total electron content projection system that considers ionospheric thickness and tilt angle. Addressing the significant discrepancy between the VTEC obtained by existing methods and the actual VTEC of the ionosphere, which causes considerable impact on ionospheric correction in fields such as satellite navigation and communication, this invention employs several modules to take into account the thickness of the ionosphere itself and its angle with the ground, resulting in a new and more rigorous projection method. This improves the accuracy of the projection results and provides better initial data for ionospheric correction in fields such as satellite navigation and communication.

[0112] It should be noted that the system embodiments provided by the present invention are used not only to implement the methods in the above method embodiments, but also to implement the methods in other method embodiments provided by the present invention. The only difference is that corresponding functional modules are set. The principle is basically the same as that of the above system embodiments provided by the present invention. As long as those skilled in the art can improve the modules in the above system embodiments by referring to the specific technical solutions in other method embodiments and combining technical features to obtain corresponding technical means and technical solutions composed of these technical means, on the basis of the above system embodiments, and on the premise of ensuring the practicality of the technical solutions, they can obtain corresponding system-like embodiments for implementing the methods in other method-like embodiments.

[0113] Based on the same inventive concept as any of the foregoing embodiments, this embodiment of the invention also provides an ionospheric total electron content projection device that considers ionospheric thickness and tilt angle, including a memory and a processor. The memory stores program instructions that are executed by the processor, and the processor calls the program instructions to execute the ionospheric total electron content projection method that considers ionospheric thickness and tilt angle.

[0114] In embodiments of the present invention, the memory can be non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or it can be volatile memory, such as random-access memory (RAM). Memory is any other medium capable of carrying or storing desired program code having an instruction or data structure form and accessible by a computer, but is not limited thereto. The memory in embodiments of the present invention can also be a circuit or any other device capable of implementing a storage function for storing program instructions and / or data.

[0115] In this embodiment of the invention, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in this embodiment of the invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in this embodiment of the invention can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0116] Based on the same inventive concept as any of the foregoing embodiments, this embodiment of the invention also provides a non-transitory computer-readable storage medium storing computer instructions that cause the computer to execute the aforementioned method for projecting the total electron content of the ionosphere considering ionospheric thickness and tilt angle, the steps of which are as follows:

[0117] Convert the geodetic coordinates of the receiver and satellite to geocentric and geofixed coordinates;

[0118] In the geocentric coordinate system, the line connecting the receiver and the satellite is discretized into a series of discrete points, and the geodetic coordinates of each discrete point are obtained by transformation.

[0119] Based on the electron density around the discrete point, the electron density at the discrete point is obtained by interpolation, and the electron density at the discrete point is integrated to obtain the oblique electron content.

[0120] Calculate the latitude and longitude of the puncture point and two adjacent points, and calculate the distances from the receiver, satellite, and two adjacent points to the Earth's equator.

[0121] Based on the distances from the receiver, satellite, and two points adjacent to the puncture point to the Earth's equator, and combined with the Earth's altitude at the receiver, satellite, and two points adjacent to the puncture point, calculate the inclination angle of the line connecting the receiver and satellite on the ground and the inclination angle of the ionosphere.

[0122] The total electron content of the ionosphere is calculated by using the tilt angle of the line connecting the receiver and the satellite on the ground and the tilt angle of the ionosphere, combined with the oblique electron content obtained by integration.

[0123] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0124] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0125] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0126] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0127] In summary, this invention, when projecting the total electron content of the ionosphere between the satellite and the receiver, takes into account the thickness of the ionosphere itself and the angle between the ionosphere and the ground. This results in a new triangle formed by the oblique electron content (STEC), the vertical electron content (VTEC), and the ionosphere, within which VTEC is calculated. By considering the thickness of the ionosphere and its angle with the ground, the projection method of this invention is more rigorous, and the calculation results obtained using this method are closer to the true values, thus providing better initial data for ionospheric correction.

[0128] The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that includes a series of steps or units, not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. An ionospheric total electron content projection method considering ionospheric thickness and dip angle, characterized by, The method comprises the following steps: Converting the geodetic coordinates of the receiver and the satellite into the geocentric coordinates; Discretizing the line connecting the receiver and the satellite into a series of discrete points in the geocentric coordinate system, and converting the geodetic coordinates of each discrete point; Based on the electron density around the discrete points, interpolating the electron density at the discrete points, and integrating the electron density at the discrete points to obtain the slant TEC; Calculating the longitude and latitude of the piercing point and the two points adjacent to the piercing point, and calculating the distances from the receiver, the satellite, and the two points adjacent to the piercing point to the Earth's equator; According to the distances from the receiver, the satellite, and the two points adjacent to the piercing point to the Earth's equator, and combining the geodetic height of the receiver, the satellite, and the two points adjacent to the piercing point, the inclination of the line connecting the receiver and the satellite on the ground and the inclination of the ionosphere are calculated as: ， wherein, respectively the angle of the connection of the receiver and the satellite on the ground and the angle of the ionosphere, respectively the geodetic height of the receiver, the satellite and the two points adjacent to the piercing point, respectively the distance of the receiver, the satellite and the two points adjacent to the piercing point to the equator of the earth; According to the inclination of the line connecting the receiver and the satellite on the ground and the inclination of the ionosphere, and combining the slant TEC obtained by integration, the total electron content of the ionosphere is calculated as: ， Wherein, STEC is the slant TEC.

2. The method of claim 1, wherein the ionospheric total electron content projection method considers ionospheric thickness and dip angle. Based on the electron density around the discrete points, interpolating the electron density at the discrete points, comprising: Using the linear interpolation method based on triangulation to interpolate the electron density at the discrete points.

3. The method of claim 2, wherein the ionospheric total electron content projection method considers ionospheric thickness and dip angle. After obtaining the electron density at the discrete points, further comprising: Using the trapezoidal numerical integration method to integrate the electron density at the discrete points to obtain the slant TEC.

4. The method of claim 1, wherein the ionospheric total electron content projection method considers ionospheric thickness and dip angle. Calculating the longitude and latitude of the piercing point and the two points adjacent to the piercing point, comprising: Calculating the azimuth and elevation angle of the satellite relative to the receiver; According to the calculated elevation angle, the zenith angle at the receiver is calculated, and then the zenith angle at the piercing point is calculated; According to the zenith angles at the receiver and the piercing point, the geocentric angle from the receiver to the piercing point is calculated; According to the calculated geocentric angle, combining the azimuth and the longitude and latitude of the receiver, the longitude and latitude of the piercing point are calculated; The latitude of the piercing point is respectively added by a preset angle and subtracted by a preset angle to obtain the longitude and latitude of the two points adjacent to the piercing point.

5. An ionospheric total electron content projection system taking into account ionospheric thickness and dip, for implementing the method of any one of claims 1 to 4, characterized in that, Comprising: A first main module for converting the geodetic coordinates of the receiver and the satellite into the geocentric coordinates; A second main module for discretizing the line connecting the receiver and the satellite into a series of discrete points in the geocentric coordinate system, and converting the geodetic coordinates of each discrete point; A third main module for interpolating the electron density at the discrete points based on the electron density around the discrete points, and integrating the electron density at the discrete points to obtain the slant TEC; A fourth main module for calculating the longitude and latitude of the piercing point and the two points adjacent to the piercing point, and calculating the distances from the receiver, the satellite, and the two points adjacent to the piercing point to the Earth's equator; A fifth main module for calculating the inclination of the line connecting the receiver and the satellite on the ground and the inclination of the ionosphere according to the distances from the receiver, the satellite, and the two points adjacent to the piercing point to the Earth's equator, and combining the geodetic height of the receiver, the satellite, and the two points adjacent to the piercing point; A sixth main module for calculating the total electron content of the ionosphere according to the inclination of the line connecting the receiver and the satellite on the ground and the inclination of the ionosphere, and combining the slant TEC obtained by integration.

6. An ionospheric total electron content projection device that takes into account ionospheric thickness and dip, the device comprising: The application discloses an ionosphere total electron content projection method considering ionosphere thickness and inclination, comprising a memory and a processor, wherein the memory stores program instructions executed by the processor, and the processor invokes the program instructions to execute the ionosphere total electron content projection method considering ionosphere thickness and inclination according to any one of claims 1 to 4.

7. A non-transitory computer-readable storage medium, comprising: The non-transitory computer readable storage medium stores computer instructions, and the computer instructions make the computer execute the ionosphere total electron content projection method considering ionosphere thickness and inclination according to any one of claims 1 to 4.

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