A dynamic adjustment method for over-the-horizon communication parameters based on evaporation waveguide

Abstract

The present invention relates to the field of radio transmission and discloses a method for dynamically adjusting over-the-horizon communication parameters based on an evaporation duct. The method comprises the following steps: installing meteorological and hydrological sensors at a specified height on an offshore launch platform to obtain meteorological and hydrological data at the specified height; using the obtained meteorological and hydrological data to calculate an evaporation duct height diagnostic value and an atmospherically corrected refractive index profile; calculating the minimum trapping frequency and critical angle of incidence under the current environment based on the obtained atmospherically corrected refractive index profile; determining a communication frequency range and antenna parameter ranges for the transmitter and receiver; and employing a particle swarm optimization algorithm to search within the communication frequency range and antenna parameter range to obtain a communication frequency with minimal propagation loss and an optimal antenna parameter configuration. The method disclosed in the present invention can output the optimal frequency for over-the-horizon communication in an evaporation duct environment in real time and dynamically adjust the system antenna parameters according to the meteorological and hydrological environment through an antenna servo system.

Description

Technical Field

[0001] The present invention relates to the field of radio transmission, and in particular to a method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide. Background Art

[0002] At present, the demand for high-reliability, high-bandwidth wireless communications is increasing in the fields of marine communications, long-distance information transmission, shipborne systems, emergency response, etc.

[0003] Evaporative ducting is a common anomalous refraction phenomenon in the near-Earth atmosphere. Under specific meteorological conditions, it can form a low-loss propagation channel for electromagnetic waves, thus enabling beyond-line-of-sight communication. Evaporative duct-based beyond-line-of-sight communication offers the advantages of long transmission distance and high bandwidth utilization, and has important application value in marine environments. However, existing beyond-line-of-sight communication systems generally suffer from the following problems: an inability to identify and determine the formation and changes of evaporative ducts based on real-time meteorological conditions; a lack of dynamic adaptive adjustment mechanisms for parameters such as communication frequency, antenna height, and elevation angle; and a system that is often based on fixed parameters measured on a single occasion, resulting in significant performance fluctuations and insufficient reliability when the duct environment changes.

[0004] Therefore, there is an urgent need for a method that can dynamically sense the evaporation waveguide structure in complex ocean environments and select the parameters of the over-the-horizon communication system in real time. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a method for dynamically adjusting beyond-line-of-sight communication parameters based on an evaporation waveguide. The method can output the optimal frequency for beyond-line-of-sight communication in an evaporation waveguide environment in real time and dynamically adjust the system antenna parameters according to the meteorological and hydrological environment through the antenna servo system.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide comprises the following steps:

[0008] Step 1: Acquisition of observation data: Install meteorological and hydrological sensors at a specified height on the offshore launch platform to obtain meteorological and hydrological data at the specified height;

[0009] Step 2: Obtaining the atmospheric correction refractive index profile: Utilizing the meteorological and hydrological data at a specified height, a diagnostic value of the evaporation duct height is calculated using an evaporation duct model; and obtaining the corresponding atmospheric correction refractive index profile using a logarithmic linear function of the atmospheric correction refractive index profile with respect to the evaporation duct height.

[0010] Step 3: Obtaining the minimum trapping frequency and critical angle of incidence: Based on the obtained atmospheric corrected refractive index profile, calculate its refractive index gradient and evaporation duct height to obtain the minimum trapping frequency in the current environment. Simultaneously, calculate the duct strength based on the corrected refractive index profile to further obtain the critical angle of incidence.

[0011] Step 4: Determine the communication frequency range and the antenna parameter ranges of the transmitter and receiver based on the minimum trapping frequency, critical incident angle, evaporation waveguide height, and empirical values;

[0012] Step 5: Use the particle swarm optimization algorithm to search within the communication frequency range and antenna parameter range to obtain the communication frequency with the minimum propagation loss and the optimal antenna parameter configuration.

[0013] In the above scheme, the meteorological and hydrological data in step 1 include observation data of air pressure, atmospheric temperature, relative humidity, wind speed and sea surface temperature.

[0014] In the above scheme, the evaporation waveguide model in step 2 includes PJ, NPS, BYC, NWA, LKB or NRL model.

[0015] In the above scheme, in step 2, the atmospheric correction refractive index is calculated as follows:

[0016] ;

[0017] Where: is the atmospheric corrected refractive index at an altitude of 0m, is the height, is the atmospheric corrected refractive index at height z, =0.00015m, is the evaporation waveguide height.

[0018] In the above scheme, in step 3, the minimum trap frequency The calculation of is as follows:

[0019] ;

[0020] Where, is the atmospheric correction refractive index, is the height, is the evaporation waveguide height.

[0021] In the above scheme, in step 3, the critical angle of incidence Its expression is as follows:

[0022] ;

[0023] Where, is the waveguide strength, , is the atmospheric corrected refractive index at an altitude of 0m, is the minimum atmospheric correction refractive index value.

[0024] In the above scheme, in step 4, the communication frequency range is determined to be ,in, is the minimum trapping frequency, It is 12.5GHz.

[0025] In the above scheme, in step 4, the antenna parameters of the transmitter and receiver include the height of the transmitting antenna , receiving antenna height , Transmitting antenna elevation angle and the receiving antenna elevation angle , the determined antenna parameter range is: transmitting antenna height , receiving antenna height , Transmitting antenna elevation angle , receiving antenna elevation angle , is the evaporation duct height, is the critical angle of incidence.

[0026] In the above solution, the specific method of step five is as follows:

[0027] First, the link distance is calculated based on the latitude and longitude of the transmitting platform and the latitude and longitude of the receiving platform. :

[0028] ;

[0029] in, is the radius of the Earth, are the latitudes of the transmitter and receiver, respectively, expressed in radians; are the longitudes of the transmitter and receiver, respectively, expressed in radians; is the difference in longitude between the transmitter and receiver;

[0030] Secondly, construct the propagation loss function :

[0031] ;

[0032] Where: is the antenna height; is the frequency of electromagnetic waves; is the distance in the horizontal direction; M is the atmospheric correction refractive index profile; is the propagation factor, which is a function of the transmitting antenna frequency, antenna height, antenna elevation angle, link distance and atmospheric correction refractive index profile. It can be calculated by the parabolic equation method and the unit is V / m;

[0033] Then, based on the determined link distance and loss function The particle swarm optimization algorithm is used for optimization to output the communication frequency with the minimum propagation loss and the optimal antenna parameter configuration.

[0034] In a further technical solution, the specific method of optimizing using the particle swarm optimization algorithm is as follows:

[0035] (1) Parameter initialization, setting the particle swarm size and the maximum number of iterations , define a multidimensional search parameter space, including the following variables: communication frequency , Transmitting antenna height , receiving antenna height , Transmitting antenna elevation angle , receiving antenna elevation angle ; for each particle Randomly initialize its position vector in the above five-dimensional search space With velocity vector ;

[0036] (2) Calculate the fitness to minimize the propagation loss and the horizontal distance is the link distance between the transmitting platform and the receiving platform Under the condition of , the designed fitness function is:

[0037] ;

[0038] (3) Update particle velocity and position to guide individual and global optimality;

[0039] ;

[0040] in, is the inertia weight, Indicates the The particle in The velocity vector at the iteration, Indicates the The particle in The position vector at the iteration, Indicates the The particle in The speed of the iteration, Indicates the The particle in The updated position after iterations, is the individual and group learning factor, and its value range is for A uniform random number between For particles In the The historical best position of the iteration, For the current group The global optimal position of the iteration;

[0041] (4) Repeat steps (2) and (3) until the termination condition is reached, and output the optimal parameter combination of the final particle swarm:

[0042] ;

[0043] That is, find the frequency point with the minimum propagation loss in the search space and output the optimal communication frequency and the corresponding optimal transmitting antenna height , optimal receiving antenna height , optimal transmitting antenna elevation angle , and the optimal receiving antenna elevation angle .

[0044] Through the above technical solution, the present invention provides a method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide, which has the following beneficial effects:

[0045] 1. By acquiring meteorological and hydrological parameters in real time on the observation platform and dynamically calculating the atmospheric corrected refractive index profile using an evaporation duct model, this invention accurately identifies evaporation duct characteristics and thus precisely derives key propagation parameters such as minimum trapping frequency, critical angle of incidence, and antenna height. Based on this, the transmitting platform can calculate the optimal communication frequency and system antenna parameters in real time.

[0046] 2. This invention uses a particle swarm optimization algorithm to jointly optimize key communication system parameters (including communication frequency, antenna height, and elevation angle) to determine the optimal communication frequency and antenna configuration parameters. In a multidimensional search space, the particle swarm's global and local search mechanisms effectively minimize propagation losses, thereby improving received power and signal-to-noise ratio, and enhancing the stability and reliability of the communication link.

[0047] 3. The antenna servo systems on the transmitting and receiving platforms can precisely adjust the receiving platform's antenna parameters based on the transmitting platform's real-time updated antenna height, elevation angle, longitude and latitude, achieving dynamic alignment of the dual-end link. This real-time collaborative mechanism significantly enhances the communication system's adaptability and deployment efficiency in complex marine environments.

[0048] This method has the advantages of strong real-time performance, simple implementation, and flexible deployment, providing solid support for building an efficient and reliable maritime beyond-line-of-sight communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0050] Figure 1 This is a flow chart of a method for dynamically adjusting parameters of over-the-horizon communication based on an evaporation waveguide disclosed in an embodiment of the present invention;

[0051] Figure 2 A schematic diagram of a particle swarm optimization algorithm disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0053] The present invention provides a method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide, such as Figure 1 As shown, the following steps are included:

[0054] Step 1: Acquisition of observation data: Install meteorological and hydrological sensors at a specified altitude on the offshore launch platform to obtain meteorological and hydrological data at the specified altitude.

[0055] Install air pressure sensors, temperature and humidity sensors, ultrasonic three-dimensional wind sensors, and infrared sensors at the specified height of the ship-based launch platform or buoy. Calibrate all sensors before and after installation to obtain air pressure, atmospheric temperature, relative humidity, wind speed, and sea surface temperature at the specified height.

[0056] The transmitting end of the beyond-line-of-sight communication system is an offshore launch platform, including a ship-based launch platform or a buoy, and the receiving end can be a ship-based launch platform or a buoy, or a shore-based platform.

[0057] Step 2: Obtaining the atmospheric correction refractive index profile: Using the meteorological and hydrological data obtained at a specified height, the evaporation duct height diagnostic value is calculated through the evaporation duct model; and the corresponding atmospheric correction refractive index profile is obtained using the logarithmic linear function of the atmospheric correction refractive index profile with respect to the evaporation duct height.

[0058] The evaporation waveguide models include PJ, NPS, BYC, NWA, LKB or NRL models, all of which are existing known models.

[0059] The atmospheric corrected refractive index is calculated as follows:

[0060] ;

[0061] Where: is the atmospheric corrected refractive index at an altitude of 0m, is the height, is the atmospheric corrected refractive index at height z, =0.00015m, is the evaporation waveguide height.

[0062] Step 3: Obtain the minimum trapping frequency and critical angle of incidence: Based on the obtained atmospheric corrected refractive index profile, calculate its refractive index gradient and evaporation duct height to obtain the minimum trapping frequency under the current environment; at the same time, calculate the duct strength based on the corrected refractive index profile to further obtain the critical angle of incidence.

[0063] Minimum trap frequency The calculation of is as follows:

[0064] ;

[0065] Where, is the atmospheric correction refractive index, is the height, is the evaporation waveguide height.

[0066] critical angle of incidence Its expression is as follows:

[0067] ;

[0068] Where, is the waveguide strength, , is the atmospheric corrected refractive index at an altitude of 0m, is the minimum atmospheric correction refractive index value.

[0069] Step 4: Determine the communication frequency range and the antenna parameter ranges of the transmitter and receiver based on the minimum trapping frequency, critical incident angle, evaporation waveguide height, and empirical values.

[0070] The antenna parameters of the transmitting platform and the receiving platform include the transmitting antenna height , receiving antenna height , Transmitting antenna elevation angle and the receiving antenna elevation angle .

[0071] To ensure the formation of an evaporation waveguide over-the-horizon communication link, the communication frequency Should meet the following requirements:

[0072] ;

[0073] Combined with the empirical value, the communication frequency range is determined as ,in, is the minimum trapping frequency, It is 12.5GHz.

[0074] This angle is the maximum elevation angle allowed for electromagnetic waves to enter and maintain waveguide propagation in the current atmospheric structure. The actual emission elevation angle of the electromagnetic wave must meet the following requirements:

[0075] ;

[0076] Finally, in order to form a stable waveguide propagation path, the transmitting antenna height Need to meet:

[0077] ;

[0078] To ensure that the initial path of the electromagnetic wave is within the waveguide capture range.

[0079] The antenna parameter range determined based on empirical values ​​is: , receiving antenna height , Transmitting antenna elevation angle , receiving antenna elevation angle , is the evaporation duct height, is the critical angle of incidence.

[0080] Step 5: Use the particle swarm optimization algorithm to search within the communication frequency range and antenna parameter range to obtain the communication frequency with the minimum propagation loss and the optimal antenna parameter configuration.

[0081] First, the link distance is calculated based on the latitude and longitude of the transmitting platform and the latitude and longitude of the receiving platform. :

[0082] ;

[0083] in, is the radius of the Earth, are the latitudes of the transmitter and receiver, respectively, expressed in radians; are the longitudes of the transmitter and receiver, respectively, expressed in radians; is the difference in longitude between the transmitter and receiver;

[0084] Secondly, construct the propagation loss function :

[0085] ;

[0086] Where: is the antenna height; is the frequency of electromagnetic waves; is the distance in the horizontal direction; M is the atmospheric correction refractive index profile; is the propagation factor, which is a function of the transmitting antenna frequency, antenna height, antenna elevation angle, link distance and atmospheric correction refractive index profile. It can be calculated by the parabolic equation method and the unit is V / m;

[0087] Then, based on the determined link distance and loss function Use Figure 2 The particle swarm optimization algorithm shown in the figure is used for optimization. The specific method is as follows:

[0088] (1) Parameter initialization, setting the particle swarm size and the maximum number of iterations , define a multidimensional search parameter space, including the following variables: communication frequency , Transmitting antenna height , receiving antenna height , Transmitting antenna elevation angle , receiving antenna elevation angle ; for each particle Randomly initialize its position vector in the above five-dimensional search space With velocity vector ;

[0089] (2) Calculate the fitness to minimize the propagation loss and the horizontal distance is the link distance between the transmitting platform and the receiving platform Under the condition of , the designed fitness function is:

[0090] ;

[0091] (3) Update particle velocity and position to guide individual and global optimality;

[0092] ;

[0093] in, is the inertia weight, Indicates the The particle in The velocity vector at the iteration, Indicates the The particle in The position vector at the iteration, Indicates the The particle in The speed of the iteration, Indicates the The particle in The updated position after iterations, is the individual and group learning factor, and its value range is for A uniform random number between For particles In the The historical best position of the iteration, For the current group The global optimal position of the iteration;

[0094] (4) Repeat steps (2) and (3) until the maximum number of iterations is reached, and output the optimal parameter combination of the final particle swarm:

[0095] ;

[0096] That is, find the frequency point with the minimum propagation loss in the search space and output the optimal communication frequency and the corresponding optimal transmitting antenna height , optimal receiving antenna height , optimal transmitting antenna elevation angle , and the optimal receiving antenna elevation angle .

[0097] The launch platform continuously collects current meteorological and hydrological data, including temperature, humidity, air pressure, wind speed, and sea surface temperature. Based on this data, it updates the atmospheric refractive index profile in real time. Combining waveguide structural parameters with communication link requirements, the platform dynamically calculates the optimal communication frequency and transmit and receive antenna heights and elevation angles to match the current evaporation waveguide propagation conditions.

[0098] Through the built-in data transmission module, the latitude and longitude of the launch platform are transmitted , and the receiving antenna height calculated in real time by the launch platform , receiving antenna elevation angle The receiving end is based on the received receiving antenna height. , receiving antenna elevation angle , adjusted through the antenna servo system and combined with its own longitude and latitude Information, real-time calculation of the azimuth of the receiving antenna, thereby completing the precise adjustment of the transmitting and receiving antennas and the azimuth of the transmitting platform and the azimuth of the receiving platform , are in opposite directions, so the azimuth of the receiving end can be obtained by reversing the azimuth of the transmitting end:

[0099] ;

[0100] This mechanism ensures that in a complex ocean evaporation waveguide environment, the communicating parties can quickly adjust antenna parameters according to environmental changes and maintain stable coupling of the waveguide propagation path.

[0101] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide, characterized in that: The steps include: Step 1: Acquisition of observation data: Install meteorological and hydrological sensors at a specified height on the offshore launch platform to obtain meteorological and hydrological data at the specified height; Step 2: Obtaining the atmospheric correction refractive index profile: Utilizing the meteorological and hydrological data at a specified height, a diagnostic value of the evaporation duct height is calculated using an evaporation duct model; and obtaining the corresponding atmospheric correction refractive index profile using a logarithmic linear function of the atmospheric correction refractive index profile with respect to the evaporation duct height. Step 3: Obtaining the minimum trapping frequency and critical angle of incidence: Based on the obtained atmospheric corrected refractive index profile, calculate its refractive index gradient and evaporation duct height to obtain the minimum trapping frequency in the current environment. Simultaneously, calculate the duct strength based on the corrected refractive index profile to further obtain the critical angle of incidence. Step 4: Determine the communication frequency range and the antenna parameter ranges of the transmitter and receiver based on the minimum trapping frequency, critical incident angle, evaporation waveguide height, and empirical values; Step 5: Use the particle swarm optimization algorithm to search within the communication frequency range and antenna parameter range to obtain the communication frequency with the minimum propagation loss and the optimal antenna parameter configuration; In step 4, the communication frequency range is determined to be ,in, is the minimum trapping frequency, 12.5GHz; In step 4, the antenna parameters of the transmitter and receiver include the height of the transmitting antenna , receiving antenna height , Transmitting antenna elevation angle and the receiving antenna elevation angle , the determined antenna parameter range is: transmitting antenna height , receiving antenna height , Transmitting antenna elevation angle , receiving antenna elevation angle , is the evaporation duct height, is the critical angle of incidence.

2. The method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide according to claim 1, characterized in that: The meteorological and hydrological data in step 1 include observation data of air pressure, atmospheric temperature, relative humidity, wind speed and sea surface temperature.

3. The method for dynamically adjusting parameters of over-the-horizon communication based on evaporation waveguide according to claim 1, characterized in that: The evaporation waveguide models in step 2 include PJ, NPS, BYC, NWA, LKB or NRL models.

4. The method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide according to claim 1, characterized in that: In step 2, the atmospheric correction refractive index is calculated as follows: ； Where: is the atmospheric corrected refractive index at an altitude of 0m, is the height, is the atmospheric corrected refractive index at height z, =0.00015m, is the evaporation waveguide height.

5. The method for dynamically adjusting parameters of over-the-horizon communication based on evaporation waveguide according to claim 1, characterized in that: In step 3, the minimum trap frequency The calculation is as follows: ； Where, is the atmospheric correction refractive index, is the height, is the evaporation waveguide height.

6. The method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide according to claim 1, characterized in that: In step 3, the critical angle of incidence Its expression is as follows: ； Where, is the waveguide strength, , is the atmospheric corrected refractive index at an altitude of 0m, is the minimum atmospheric correction refractive index value.

7. The method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide according to claim 1, characterized in that: The specific method of step five is as follows: First, the link distance is calculated based on the latitude and longitude of the transmitting platform and the latitude and longitude of the receiving platform. : ； in, is the radius of the Earth, are the latitudes of the transmitter and receiver, respectively, expressed in radians; are the longitudes of the transmitter and receiver, respectively, expressed in radians; is the difference in longitude between the transmitter and receiver; Secondly, construct the propagation loss function : ； Where: is the antenna height; is the frequency of electromagnetic waves; is the distance in the horizontal direction; M is the atmospheric correction refractive index profile; is the propagation factor, which is a function of the transmitting antenna frequency, antenna height, antenna elevation angle, link distance and atmospheric correction refractive index profile. It can be calculated by the parabolic equation method and the unit is V / m; Then, based on the determined link distance and loss function The particle swarm optimization algorithm is used for optimization to output the communication frequency with the minimum propagation loss and the optimal antenna parameter configuration.

8. The method for dynamically adjusting over-the-horizon communication parameters based on an evaporation waveguide according to claim 7, characterized in that: The specific method of using particle swarm optimization algorithm for optimization is as follows: (1) Parameter initialization, setting the particle swarm size and the maximum number of iterations , defining a multidimensional search parameter space, The following variables are included: Communication frequency , Transmitting antenna height , receiving antenna height , Transmitting antenna elevation angle , receiving antenna elevation angle ; for each particle Randomly initialize its position vector in the above five-dimensional search space With velocity vector ; (2) Calculate the fitness to minimize the propagation loss and the horizontal distance is the link distance between the transmitting platform and the receiving platform Under the condition of , the designed fitness function is: ； (3) Update particle velocity and position to guide individual and global optimality; ； in, is the inertia weight, Indicates the The particle in The velocity vector at the iteration, Indicates the The particle in The position vector at the iteration, Indicates the The particle in The speed of the iteration, Indicates the The particle in The updated position after iterations, is the individual and group learning factor, and its value range is for A uniform random number between For particles In the The historical best position of the iteration, For the current group The global optimal position of the iteration; (4) Repeat steps (2) and (3) until the termination condition is reached, and output the optimal parameter combination of the final particle swarm: ； That is, find the frequency point with the minimum propagation loss in the search space and output the optimal communication frequency and the corresponding optimal transmitting antenna height , optimal receiving antenna height , optimal transmitting antenna elevation angle , and the optimal receiving antenna elevation angle .

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