An engineering algorithm and device for correcting the atmospheric attenuation factor of electromagnetic waves

Abstract

The present invention discloses an engineering algorithm and device for calculating the atmospheric attenuation correction factor for electromagnetic waves. The algorithm comprises the following steps: S1, obtaining the zenith attenuation (#imgabs0#) of a certain frequency based on data; S2, simulating and calculating the engineering estimate A' at different angles using the zenith attenuation (#imgabs1#); S3, modeling the atmospheric attenuation correction factor N by fitting an exponential function using the variation of angles; S4, recalculating the atmospheric attenuation at different frequencies using the modeled formula; and S5, repeating steps S2-S4, comparing the recalculated result with the ITU theoretical calculated value, and iterating the fitting to obtain a constant that conforms to a value within 10 degrees and an error within 5%. The present invention calculates attenuation correction factors for different frequencies based on zenith attenuation, considers the error range of the actual attenuation, and uses the reference calculated value of the standard ITU organization as a comparison to deduce the attenuation correction factors for different frequency bands. This method can provide fast and accurate attenuation values in engineering applications.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication engineering applications, and in particular to an electromagnetic wave atmospheric attenuation correction factor engineering algorithm and device. Background Art

[0002] Gaseous attenuation refers to the absorption or scattering of electromagnetic radiation by a gas, resulting in a reduction in the energy of the radiation as it passes through the gas. Recommendation ITU R P.618-13 (12 / 2017), "Propagation data and prediction methods required for the design of Earth-to-space telecommunication systems," states that, typically above elevation angles of 10 degrees, only gaseous attenuation, rain and cloud attenuation, and possibly scintillation are significant, depending on propagation conditions. Recommendation ITU R P.676-13 (08 / 2022), "Radiowave attenuation in atmospheric gases and related effects," provides a comprehensive methodology for calculating atmospheric gas attenuation.

[0003] Attenuation due to atmospheric gases is entirely due to absorption and depends primarily on frequency, elevation angle, altitude above the horizon, and water vapor density (absolute humidity). At frequencies below 10 GHz, this attenuation is generally negligible. Above 10 GHz, its importance increases, especially at low elevation angles.

[0004] According to the ITU R P.676 standard, the line-by-line gas attenuation method is used for atmospheric attenuation analysis. Line-by-line calculation involves calculating each spectral line individually to obtain the gas attenuation across the entire spectral range. This method is commonly used to accurately calculate the spectral absorption and emission characteristics of gases and to study their spectral properties. By accumulating the individual spectral lines of oxygen and water vapor at any pressure, temperature, and humidity, it is possible to accurately calculate the specific attenuation at frequencies up to 1000 GHz, primarily due to dry air and water vapor.

[0005] Figure 1 The specific attenuation (step size of 1 GHz) in the frequency band 0-1000 GHz is given under two conditions: air pressure of 1013.25 Pa, temperature of 15°C, water vapor density of 7.5 g / m3 (standard) and dry air (dry), calculated using the prediction method.

[0006] According to the standard attenuation chart provided by ITU-R P.676-13, the specific attenuation values corresponding to the frequency range of 0-100GHz at an air pressure of 1013.25Pa, a temperature of 15°C, and a water vapor density of 7.5g / m3 (standard) are as follows: Figure 2 shown.

[0007] In the process of electromagnetic wave communication less than 100G, it can be seen that the attenuation caused by the electromagnetic wave passing through the atmosphere forms two peaks, approximately at 22G and 60G.

[0008] High-precision gas radiation calculations are crucial in scientific research and engineering applications across multiple disciplines. While the line-by-line method, the most accurate gas radiation model, is difficult to use in practical applications due to its complex calculation process and high computational time consumption, it is primarily used as a benchmark to measure the accuracy of other radiation models. Summary of the Invention

[0009] In order to solve the problem of the complex calculation process of the original line-by-line method, the present invention provides an engineering algorithm for the electromagnetic wave atmospheric attenuation correction factor, which simplifies the original calculation formula and forms a fast calculation method for atmospheric attenuation in satellite communications with theoretical basis support, achieving consistency between the atmospheric attenuation calculated by simulation and the measured atmospheric attenuation in actual engineering applications.

[0010] The specific plan is as follows:

[0011] An electromagnetic wave atmospheric attenuation correction factor engineering algorithm includes the following steps:

[0012] S1, obtain the zenith attenuation of a certain frequency based on the data The zenith attenuation is the attenuation value of the electromagnetic wave passing through the atmosphere when the elevation angle is 90 degrees;

[0013] S2, attenuation through the zenith The engineering estimate value A' can be simulated and calculated at different angles;

[0014]

[0015] in, is the theoretically estimated value of zenith attenuation, in dB. is the elevation angle of the measuring station;

[0016] S3, using the angle variation law to fit the exponential function to model the atmospheric attenuation correction factor N;

[0017] S4, use the modeled formula to recalculate the atmospheric attenuation of different frequencies. Specifically, the engineering estimated value A' is corrected according to the correction factor N to obtain the final atmospheric attenuation value ;

[0018] S5, repeat steps S2-S4, compare the recalculated results with the ITU theoretical calculated values, repeatedly iterate and fit to find a constant that is less than 10 degrees and within an error of 5%. The correction factor N is calculated as follows: ;in, is a natural constant, is the elevation angle of the measuring station, in degrees.

[0019] Preferably, in step S1, the target frequency range is 2 - 100 GHz, with an interval of 1 GHz.

[0020] The present invention also discloses a device for implementing an engineering algorithm for the atmospheric attenuation correction factor of electromagnetic waves, including:

[0021] A data acquisition module for acquiring zenith attenuation data at a certain frequency;

[0022] A simulation calculation module for calculating engineering estimation values at different angles based on the zenith attenuation;

[0023] A modeling module for modeling the atmospheric attenuation correction factor N;

[0024] A recalculation module for performing recalculation of atmospheric attenuation using the modeled formula;

[0025] A comparison module for comparing the recalculation result with the ITU theoretical calculation value;

[0026] A correction module for iteratively fitting to obtain a constant that meets the error requirement and summarizing the calculation formula for the correction factor N.

[0027] The present invention also discloses a computer-readable storage medium with a computer program stored thereon. After the computer program runs, it executes the algorithm described in any one of the above.

[0028] The present invention also discloses a computer system, including a processor and a storage medium. The storage medium stores a computer program, and the processor reads and runs the computer program from the storage medium to execute the algorithm described in any one of the above.

[0029] The beneficial effects of the present invention are as follows:

[0030] Based on the zenith attenuation, the present invention calculates the attenuation correction factor at different frequencies, considers the error range of the actual attenuation amount, uses the reference calculation amount of the standard ITU organization for comparison, and calculates the attenuation correction amount at different frequency bands, which can provide a fast and accurate attenuation value during the engineering application process.

[0031] Compared with the ITU standard calculation value, above an elevation angle of 10 degrees, the error does not exceed 5%. It solves the complex calculation process of the original line-by-line method, simplifies the original calculation formula, forms a fast calculation method for atmospheric attenuation in the satellite communication process supported by a theoretical basis, and achieves the consistency between the simulated atmospheric attenuation and the measured value in actual engineering applications. Description of the Drawings

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0033] Figure 1 It is the specific attenuation value standard diagram of ITU-R P.676-13 (0 - 1000 GHz);

[0034] Figure 2 It is the specific attenuation value standard diagram of ITU-R P.676-13 (0 - 100 GHz);

[0035] Figure 3 It is the schematic diagram of the atmospheric attenuation and the zenith attenuation path. Specific Embodiments

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0037] Based on the ITU atmospheric attenuation theory method, the present invention focuses on the relationship between the zenith attenuation and the station elevation angle at different frequencies, uses software to deduce an engineering simplified algorithm, and through analyzing the comparison between the engineering calculation results and the theoretical calculation results, can accurately determine the attenuation function through the station elevation angle parameter and the attenuation amount change, so as to calculate more conveniently and obtain the atmospheric attenuation value generated when passing through the atmosphere at different frequencies (2 - 100G, with an interval of 1G) from the perspective of engineering practice applications. The basic principle and process are as Figure 3 shown.

[0038] As shown in the figure, h1 is the schematic height of the low-density atmosphere layer, and h2 is the schematic height of the high-density atmosphere layer. Point A is the location of the station, communicating with the satellite at point B. At the elevation angle of , the length of the path through the atmosphere is L. R is the radius of the earth, and H is the theoretical height of the atmosphere that affects the communication electromagnetic wave. Due to its different densities, the density of the atmosphere gradually decreases from a higher density near the ground to a lower density.

[0039] When considering the zenith attenuation corresponding to H, then L corresponds to the in-atmosphere propagation path when the corresponding elevation angle is and the atmospheric attenuation value is considered. According to this idea, only the zenith attenuation needs to be converted into the elevation angle of The atmospheric attenuation value, and then by subtracting the value of the correction factor N corresponding to the frequency, the atmospheric attenuation value of the measuring station in a certain frequency band corresponding to the length L can be obtained.

[0040] Specifically, an engineering algorithm for the correction factor of electromagnetic wave atmospheric attenuation includes the following steps:

[0041] S1. Obtain the zenith attenuation at a certain frequency according to the data ; The zenith attenuation is the attenuation value of the electromagnetic wave passing through the atmosphere when the elevation angle is 90 degrees. Among them, the target frequency range is 2 - 100 GHz, with an interval of 1 GHz.

[0042] S2. Through the zenith attenuation The engineering estimated value A' at different angles can be simulated and calculated;

[0043]

[0044] Among them, is the theoretical calculation value of the zenith attenuation, with the unit of dB, is the elevation angle of the measuring station.

[0045] S3. Use the variation law of the angle to fit the exponential function to model the atmospheric attenuation correction factor N.

[0046] S4. Use the modeled formula to recalculate the atmospheric attenuation at different frequencies. Specifically, correct the engineering estimated value A' according to the correction factor N to obtain the final atmospheric attenuation value .

[0047] S5. Repeat steps S2 - S4, compare the recalculation results with the ITU theoretical calculation values, and iteratively fit to find the constant that meets the conditions of less than 10 degrees and an error within 5%. That is: optimize the correction factor parameters by comparing with the ITU theoretical calculation values until the elevation angle ≥ 10° and the error ≤ 5%; summarize the calculation formula of the correction factor N as follows ; Among them, is the natural constant, is the elevation angle of the measuring station, with the unit of degree.

[0048] The present invention also discloses a device for implementing the engineering algorithm of the correction factor of electromagnetic wave atmospheric attenuation, including:

[0049] A data acquisition module for acquiring the zenith attenuation data at a certain frequency;

[0050] A simulation calculation module for calculating the engineering estimated values at different angles according to the zenith attenuation;

[0051] A modeling module for modeling the atmospheric attenuation correction factor N;

[0052] The recalculation module is used to recalculate atmospheric attenuation using the modeled formula;

[0053] Comparison module, used to compare the recalculated results with the ITU theoretical calculation values;

[0054] The correction module is used to repeatedly iterate and fit to obtain a constant that meets the error requirements and summarize the calculation formula of the correction factor N.

[0055] Example: Taking the operating frequency of 14 GHz as an example, the attenuation correction factor N is calculated, and the results are shown in Table 1. The requirement of an error of less than 5% above 10 degrees is met.

[0056] Table 1: Attenuation correction results for an operating frequency of 14 GHz

[0057]

[0058] Using the steps of the present invention to calculate the attenuation of electromagnetic waves passing through the atmosphere, a typical industrial computer takes less than 1 millisecond. The line-by-line method, on the other hand, takes more than 1 second. The present invention reduces the calculation time by three orders of magnitude.

[0059] This method calculates attenuation correction factors for different frequencies based on zenith attenuation. Taking into account the error range of actual attenuation and using the reference calculated values from the ITU standard for comparison, it infers attenuation corrections for different frequency bands, enabling rapid and accurate attenuation values to be provided in engineering applications. Furthermore, compared with the calculated values from the ITU standard, the error in this method for elevation angles above 10 degrees is less than 5%. This method eliminates the complex calculation process of the existing line-by-line method and simplifies the original calculation formula, forming a theoretically supported method for rapid calculation of atmospheric attenuation during satellite communications. This method ensures consistency between simulated atmospheric attenuation and actual measurements in engineering applications.

[0060] The present invention also discloses a computer-readable storage medium and a computer system. The medium stores a computer program, which, when executed, executes any of the algorithms described above. The computer system includes a processor and a storage medium. The storage medium stores the computer program, and the processor reads and executes the computer program from the storage medium to execute any of the algorithms described above.

[0061] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

[0062] The foregoing description of the disclosure has been provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0063] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An engineering algorithm for the correction factor of electromagnetic wave atmospheric attenuation, characterized in that, Including the following steps: S1. Obtain the zenith attenuation at a certain frequency according to the data ; The zenith attenuation is the attenuation value of electromagnetic waves passing through the atmosphere when the elevation angle is 90 degrees; S2, through zenith attenuation The engineering estimated value A' at different angles can be simulated and calculated; ； Among them, is the theoretical calculation value of zenith attenuation, with the unit of dB, is the elevation angle of the station; S3, modeling the atmospheric attenuation correction factor N by fitting an exponential function using the variation law of the angle; S4. Recalculate the atmospheric attenuation at different frequencies using the modeled formula. Specifically, correct the engineering estimated value A' according to the correction factor N to obtain the final atmospheric attenuation value ; S5. Repeat steps S2 - S4, compare the recalculation results with the ITU theoretical calculation values, and iteratively fit repeatedly to obtain a constant that meets the conditions of being below 10 degrees and having an error within 5%. The formula for summarizing the correction factor N is as follows ; where is the natural constant, is the elevation angle of the measuring station, with the unit of degree.

2. The algorithm according to claim 1, wherein: In step S1, the target frequency range is 2 - 100 GHz, with an interval of 1 GHz.

3. An apparatus for implementing the engineering algorithm of the electromagnetic wave atmospheric attenuation correction factor according to any one of claims 1-2, characterized in that Including: A data acquisition module for acquiring zenith attenuation data at a certain frequency; A simulation calculation module for calculating the engineering estimation values at different angles based on the zenith attenuation; A modeling module for modeling the atmospheric attenuation correction factor N; A recalculation module for recalculating the atmospheric attenuation using the modeled formula; A comparison module for comparing the recalculation result with the ITU theoretical calculation value; A correction module for iteratively fitting to find the constant that meets the error requirement and summarizing the calculation formula for the correction factor N.

4. A computer-readable storage medium, characterized in that: A computer program is stored on the medium. After the computer program runs, it executes the algorithm described in any one of claims 1 to 2.

5. A computer system, characterized in that: Including a processor and a storage medium. A computer program is stored on the storage medium. The processor reads and runs the computer program from the storage medium to execute the algorithm described in any one of claims 1 to 2.

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