Parameter optimization method based on evaporation waveguide and troposphere scattering mixed channel

Abstract

The invention discloses a parameter optimization method based on an evaporation waveguide and troposphere scattering mixed channel, and the method comprises the steps: calculating the loss of a microwave propagation path through simulating a near sea surface evaporation waveguide and troposphere scattering environment in combination with an evaporation waveguide model, a troposphere scattering model, an atmospheric absorption attenuation model and a parabolic equation model; and obtaining the optimal transmitting antenna height, the optimal receiving antenna height and the optimal electromagnetic wave frequency under the evaporation waveguide and troposphere scattering mixed channel by using the target function and a global optimization algorithm. The method disclosed by the invention can adapt to application scenes such as complex offshore beyond visual range communication, can provide a flexible optimization scheme for different offshore propagation conditions and distances, and realizes all-weather beyond visual range communication by combining the advantages of an evaporation waveguide channel and a troposphere scattering channel; the influence of communication system parameters on electromagnetic wave propagation under an evaporation waveguide and troposphere scattering mixed channel can be effectively reflected, the loss of an electromagnetic wave propagation path is remarkably reduced, and the reliability of signal transmission is improved.

Description

Technical Field

[0001] The present invention belongs to the technical fields of near-sea surface evaporation ducts, tropospheric scatterings, over-the-horizon communications at sea, etc., and particularly relates to a parameter optimization method based on a hybrid channel of evaporation ducts and tropospheric scatterings. Background Art

[0002] An atmospheric duct is a special refractive atmospheric structure formed in the troposphere and widely exists in the world's major oceans. There are mainly three types of atmospheric ducts: evaporation ducts, surface ducts, and elevated ducts. Among them, the evaporation duct is considered to be a main propagation mechanism leading to over-the-horizon transmission in the near-sea surface microwave band. An evaporation duct is a natural microwave propagation channel formed near the sea surface due to seawater evaporation. When the transmitting antenna is within the evaporation duct, the atmospheric refractive index shows a negative gradient, causing the microwave to refract downward and propagate. The microwave energy is trapped in the evaporation duct layer, which can reduce the microwave propagation path loss and significantly affect the operating range of shipborne radars and communication systems. Tropospheric scatter propagation is an over-the-horizon propagation mode in which radio waves in frequency bands such as ultra-short waves and microwaves transmit energy over hundreds to thousands of kilometers through tropospheric phenomena such as atmospheric turbulence and horizontal stratification. This propagation mode is an important means to achieve over-the-horizon communications and detections. Since tropospheric scatter communication is hardly affected by the geographical environment, the single-hop communication distance can reach more than 150 km, up to nearly a thousand kilometers at most, and it has a large transmission capacity, and has many advantages such as resistance to nuclear explosions, immunity to solar storms and geomagnetic storms, and good security and confidentiality. Tropospheric scatter communication is widely used in many fields such as over-the-horizon communications, positioning, and detection of atmospheric structures.

[0003] At present, in the actual marine environment, the air-sea factors are complex and changeable, and the evaporation duct channel and the tropospheric scatter channel coexist. Both communication methods can propagate the electromagnetic waves radiated by the communication transmitting end to places beyond the line of sight to form over-the-horizon propagation. The existing technologies mainly optimize the communication system for a single propagation mechanism (such as the evaporation duct channel or the tropospheric scatter channel), lacking a method for optimizing the parameters of a hybrid channel communication system that comprehensively considers the two propagation mechanisms.

[0004] Therefore, there is an urgent need for a communication system parameter optimization method based on a hybrid channel of evaporation ducts and tropospheric scatterings to achieve parameter optimization under the hybrid channel and improve the stability and adaptability of the communication system in a complex marine environment. Summary of the Invention

[0005] The object of the present invention is to provide a parameter optimization method based on a hybrid channel of evaporation ducts and tropospheric scatterings, which is used to determine the optimal transmitting antenna height, the optimal receiving antenna height, and the optimal electromagnetic wave frequency under the hybrid channel of evaporation ducts and tropospheric scatterings, so as to achieve the optimization of the communication system parameters under the hybrid channel.

[0006] To achieve the above tasks, the present invention adopts the following technical solutions:

[0007] A parameter optimization method based on a hybrid channel of evaporation duct and tropospheric scatter, comprising:

[0008] Constructing a hybrid channel propagation model between a signal transmitter and a signal receiver on the sea surface using relevant parameters of the signal transmitter and the signal receiver; determining the field strength distribution of the electromagnetic field in the evaporation duct channel and the field strength distribution of the electromagnetic field in the tropospheric scatter channel using the hybrid channel propagation model; wherein the relevant parameters include the refractive index of the evaporation duct environmental medium and the refractive index of the tropospheric scatter environmental medium;

[0009] Based on the field strength distribution of the electromagnetic field in the evaporation duct channel and the field strength distribution of the electromagnetic field in the tropospheric scatter channel, calculating the path loss value in the evaporation duct channel and the path loss value in the tropospheric scatter channel under the system parameters;

[0010] Determining the path loss value in the hybrid channel of evaporation duct and tropospheric scatter through the path loss value in the evaporation duct channel and the path loss value in the tropospheric scatter channel;

[0011] Establishing an objective function related to the system parameters through the path loss value in the hybrid channel of evaporation duct and tropospheric scatter;

[0012] Combining a global optimization algorithm and a preset termination condition, solving the system parameters when the value of the objective function is minimized as the optimal communication system parameters in the hybrid channel of evaporation duct and tropospheric scatter; the transmitter and the receiver perform antenna configuration and system communication according to the optimal communication system parameters.

[0013] Further, the hybrid channel propagation model is expressed as:

[0014]

[0015] wherein, k0 is the free space wave number of the electromagnetic wave; i is the imaginary unit; n(x,z) duct is the refractive index of the evaporation duct environmental medium, n(x,z) trop is the refractive index of the tropospheric scatter environmental medium; x represents the horizontal propagation distance, with the unit of km; z represents the height from the sea surface, with the unit of m; u(x,z) duct is the field strength distribution of the electromagnetic field in the evaporation duct channel calculated using the narrow-angle parabolic equation, u(x,z) trop is the field strength distribution of the electromagnetic field in the tropospheric scatter channel calculated using the wide-angle parabolic equation model.

[0016] Further, the refractive index n(x,z) of the evaporation duct environmental medium ductIt is calculated by inputting the atmospheric pressure, sea surface temperature, air temperature, absolute humidity, and wind speed components measured by the marine environment detection equipment into the evaporation duct prediction model; the evaporation duct model includes the NPS model, PJ model, MGB model, and Babin model.

[0017] The refractive index n(x,z) of the tropospheric scattering environmental medium trop is calculated by inputting meteorological parameters such as atmospheric pressure, absolute temperature, and absolute humidity measured by the tropospheric detection equipment into the atmospheric refractive index model.

[0018] Furthermore, the path loss values under the evaporation duct channel and the path loss values under the tropospheric scattering channel are calculated under the system parameters. The specific formulas are as follows:

[0019]

[0020] where PL duct (p i ) is the path loss value under the evaporation duct channel, and PL trop (p i ) is the path loss value under the tropospheric scattering channel; is the field strength distribution u(x,z) of the electromagnetic field under the evaporation duct channel duct in the field strength distribution related to the system parameter p i ; is the field strength distribution u(x,z) of the electromagnetic field under the tropospheric scattering channel trop in the field strength distribution related to the system parameter p i ; PL gas is the atmospheric absorption loss value; λ represents the wavelength of the electromagnetic wave, with the unit of m; p i represents the system parameter of the evaporation duct and tropospheric scattering hybrid channel, specifically: p i =[h t ,h r ,f]; where h t represents the height of the transmitting antenna, with the unit of m; h r represents the height of the receiving antenna, with the unit of m; f represents the frequency of the electromagnetic wave, with the unit of GHz; δ t is the evaporation duct atmospheric environment at different heights, with the unit of m; δ0 is the actual evaporation duct height, with the unit of m; x0 is the actual electromagnetic wave propagation distance, with the unit of km; PL gas is the atmospheric absorption loss value, with the unit of dB.

[0021] Furthermore, the calculation formula of the atmospheric absorption loss value PL gas is as follows:

[0022] PL gas =(γo +γ w ) × x (5)

[0023] Among them, γ o is the oxygen absorption attenuation rate, with the unit of dB / km, and γ w is the water vapor absorption attenuation rate, with the unit of dB / km. The relevant calculation formula is as follows:

[0024]

[0025] t air is the air temperature at 2 m above the sea surface, and hum is the absolute humidity at 2 m above the sea surface.

[0026] Furthermore, the path loss value under the evaporation duct and tropospheric scatter hybrid channel is determined by the path loss value under the evaporation duct channel and the path loss value under the tropospheric scatter channel, specifically as follows:

[0027] L dif = PL duct (p i ) - PL trop (p i ) (7)

[0028]

[0029] Among them, L dif is the difference between the path loss of the evaporation duct channel and the path loss of the tropospheric scatter channel, PL duct (p i ) is the path loss value under the evaporation duct channel, PL trop (p i ) is the path loss value under the tropospheric scatter channel, and PL duct,trop (p i ) is the path loss value under the evaporation duct and tropospheric scatter hybrid channel.

[0030] Furthermore, an objective function related to the system parameters is established through the path loss value under the evaporation duct and tropospheric scatter hybrid channel, expressed as:

[0031]

[0032] Among them, p i is the system parameter, PL duct,trop (p i ) is the path loss value under the evaporation duct and tropospheric scatter hybrid channel, is the objective function, δ t is the evaporation duct atmospheric environment at different heights, δ0 is the actual evaporation duct height, x represents the horizontal propagation distance, and x0 is the actual electromagnetic wave propagation distance.

[0033] Furthermore, the global optimization algorithm includes a global traversal algorithm, a genetic algorithm, a particle swarm optimization algorithm, a repulsive particle swarm algorithm, and a whale algorithm, and the maximum number of iterations j is set. max ; The termination condition is that when the height h of the transmitting antenna t , the height h of the receiving antenna r takes values in the range of 2 - 25 m, and the electromagnetic wave frequency f takes values in the range of 1 - 20 GHz. If when p i = p min at this time takes the minimum value or the number of iterations reaches j max , then p min is the optimal communication system parameter under the hybrid channel.

[0034] A communication system that uses the parameter optimization method under the hybrid channel of evaporation duct and troposcatter to optimize the communication parameters of the transmitting end and the receiving end.

[0035] A computer-readable storage medium stores a computer program; when the computer program is executed by a processor, the parameter optimization method under the hybrid channel of evaporation duct and troposcatter is implemented.

[0036] Compared with the prior art, the present invention has the following technical features:

[0037] 1. The prominent advantage of the present invention is that multiple channels often coexist at sea, but there is little research on the parameter optimization of hybrid channels. The present invention establishes a hybrid channel of evaporation duct and troposcatter at sea based on the narrow-angle parabolic equation and the wide-angle parabolic equation, describes the propagation characteristics of electromagnetic waves in different environments, and adapts to application scenarios such as complex maritime over-the-horizon communication.

[0038] 2. The evaporation duct and troposcatter hybrid channels proposed by the present invention have their own advantages and are complementary. The evaporation duct channel can effectively enhance the propagation of electromagnetic waves and reduce the propagation loss. However, the evaporation duct channel has severe fluctuations and it is difficult to achieve all-weather long-time communication. The troposcatter channel can achieve reliable over-the-horizon transmission in complex terrains and bad weather, and has strong anti-interference ability. By combining the two channels and calculating the optimal transmitting antenna height, optimal receiving antenna height, and optimal electromagnetic wave frequency under the hybrid channel, a flexible optimization scheme can be provided for different maritime propagation conditions and distances, combining the advantages of the evaporation duct channel and the troposcatter channel to achieve all-weather over-the-horizon communication.

[0039] 3. The selected ranges of electromagnetic wave frequency and antenna height proposed by the present invention can effectively reflect the influence of communication system parameters on the propagation of electromagnetic waves under the hybrid channel of evaporation duct and troposcatter, significantly reduce the loss of the electromagnetic wave propagation path, and improve the reliability of signal transmission. Description of the Drawings

[0040] Figure 1 is a schematic flow chart of the method of the present invention;

[0041] Figure 2 is a conceptual diagram of a hybrid channel of marine evaporation duct and tropospheric scatter;

[0042] Figure 3 is a schematic diagram of path loss of an evaporation duct channel, a tropospheric scatter channel, and a hybrid channel when the evaporation duct height is 13 m, the transmitting antenna height is 10 m, the receiving antenna height is 10 m, and the electromagnetic wave frequency is 5 GHz;

[0043] Figure 4 is a schematic diagram showing the variation of path loss of a hybrid channel of evaporation duct and tropospheric scatter with the transmitting antenna height, the receiving antenna height, and the electromagnetic wave frequency when the evaporation duct height is 13 m and the propagation distance is 300 km;

[0044] Figure 5 is a path loss distribution map calculated after optimization using the optimal transmitting antenna height, the optimal receiving antenna height, and the optimal electromagnetic wave frequency parameters when the evaporation duct height is 13 m and the propagation distance is 300 km. Detailed Embodiment

[0045] The present invention discloses a parameter optimization method based on a hybrid channel of evaporation duct and tropospheric scatter. By simulating the evaporation duct and tropospheric scatter environments near the sea surface, and combining the evaporation duct model, the tropospheric scatter model, the atmospheric absorption attenuation model, and the parabolic equation model to calculate the microwave propagation path loss, and using the objective function and the global optimization algorithm, the optimal transmitting antenna height, the optimal receiving antenna height, and the optimal electromagnetic wave frequency under the hybrid channel of evaporation duct and tropospheric scatter are obtained. Refer to Figure 1 and Figure 2 , the specific steps of the present invention are as follows:

[0046] Step 1, constructing a hybrid channel propagation model between the transmitting end and the receiving end by using the relevant parameters of the signal transmitting end and the signal receiving end on the sea surface; wherein the relevant parameters include the refractive index n(x, z) of the evaporation duct environment medium duct and the refractive index n(x, z) of the tropospheric scatter environment medium trop .

[0047] Determining the field strength distribution u(x, z) of the electromagnetic field in the evaporation duct channel by using the hybrid channel propagation model duct and the field strength distribution u(x, z) of the electromagnetic field in the tropospheric scatter channel trop .

[0048] During the propagation of electromagnetic waves in an evaporation duct channel, the trapping angle usually does not exceed 1°. The narrow-angle parabolic equation is selected as the propagation model of electromagnetic waves in the evaporation duct; during the propagation of electromagnetic waves in the tropospheric scattering channel, the maximum propagation angle of electromagnetic waves is greater than 1°, and the wide-angle parabolic equation is used as the propagation model of electromagnetic waves in the tropospheric scattering channel; then the hybrid channel propagation model is expressed as:

[0049]

[0050] where k0 is the free-space wave number of electromagnetic waves; i is the imaginary unit; n(x,z) duct is the refractive index of the evaporation duct environmental medium, and n(x,z) trop is the refractive index of the tropospheric scattering environmental medium; x represents the horizontal propagation distance, with the unit of km; z represents the height from the sea surface, with the unit of m; u(x,z) duct is the field strength distribution of the electromagnetic field (in the horizontal and height directions) in the evaporation duct channel calculated using the narrow-angle parabolic equation, and u(x,z) trop is the field strength distribution of the electromagnetic field (in the horizontal and height directions) in the tropospheric scattering channel calculated using the wide-angle parabolic equation model.

[0051] The refractive index n(x,z) of the evaporation duct environmental medium duct is calculated by inputting the atmospheric pressure, sea surface temperature, air temperature, absolute humidity, and wind speed components measured by ocean environmental detection equipment into the evaporation duct prediction model; the evaporation duct models include the NPS model, PJ model, MGB model, and Babin model.

[0052] The refractive index n(x,z) of the tropospheric scattering environmental medium trop is calculated by inputting the meteorological parameters such as atmospheric pressure, absolute temperature, and absolute humidity measured by the tropospheric detection equipment into the atmospheric refractive index model.

[0053] Step 2, based on the field strength distribution u(x,z) of the electromagnetic field in the evaporation duct channel duct and the field strength distribution u(x,z) of the electromagnetic field in the tropospheric scattering channel trop , calculate the path loss value PL i in the evaporation duct channel and the path loss value PL duct (p i ) and the path loss value PL of the road under the tropospheric scattering channel trop (p i ), specifically as follows:

[0054]

[0055] where PLduct (p i ) is the path loss value in the evaporation duct channel, PL trop (p i ) is the path loss value in the tropospheric scatter channel; is the field strength distribution u(x,z) of the electromagnetic field in the evaporation duct channel duct related to the system parameter p i in the relevant field strength distribution; is the field strength distribution u(x,z) of the electromagnetic field in the tropospheric scatter channel trop related to the system parameter p i in the relevant field strength distribution; PL gas is the atmospheric absorption loss value; λ represents the wavelength of the electromagnetic wave, with the unit of m; p i represents the system parameter of the mixed channel of evaporation duct and tropospheric scatter. Specifically: p i = [h t , h r , f]; where, h t represents the height of the transmitting antenna, with the unit of m; h r represents the height of the receiving antenna, with the unit of m; f represents the frequency of the electromagnetic wave, with the unit of GHz; δ t is the evaporation duct atmospheric environment at different heights, with the unit of m; δ0 is the actual evaporation duct height, with the unit of m; x0 is the actual electromagnetic wave propagation distance, with the unit of km; PL gas is the atmospheric absorption loss value, with the unit of dB; the calculation formula is as follows:

[0056] PL gas = (γ o + γ w ) × x (5)

[0057] where, γ o is the oxygen absorption attenuation rate, with the unit of dB / km, γ w is the water vapor absorption attenuation rate, with the unit of dB / km. The relevant calculation formulas are as follows:

[0058]

[0059] t air is the air temperature 2m above the sea surface, and hum is the absolute humidity 2m above the sea surface.

[0060] The actual evaporation duct height δ0 is obtained by inputting the atmospheric pressure, sea surface temperature, air temperature at 2 m above the sea surface, absolute humidity at 2 m above the sea surface, and wind speed component at 10 m above the sea surface at the center point of the offshore research into an evaporation duct prediction model, obtaining the atmospheric modified refractive index profile within a fixed range at the center point of the offshore research, and the height corresponding to the minimum modified refractive index in the atmospheric modified refractive index profile is the actual evaporation duct height.

[0061] Step 3: Determine the path loss value PL duct (p i ) and the path loss value PL trop (p i ) of the tropospheric scatter channel under the evaporation duct and tropospheric scatter mixed channel: duct,trop (p i ):

[0062] L dif = PL duct (p i ) - PL trop (p i ) (7)

[0063]

[0064] where L dif is the difference between the path loss of the evaporation duct channel and the path loss of the tropospheric scatter channel, with the unit of dB; when L dif is higher than 18 dB, the influence of the tropospheric scatter effect is more significant; under the path loss condition where L dif is lower than 18 dB, the influence of the tropospheric scatter effect on the total loss under the mixed channel is small, and the tropospheric scatter effect is considered by performing logarithmic interpolation on the path loss value PL duct (p i ).

[0065] Step 4: Establish an objective function duct,trop (p i ) related to the system parameter p i through the path loss value PL

[0066]

[0067] Step 5: Combine the global optimization algorithm and the preset termination condition to solve for the system parameter p when the value of the objective function i is minimized as the optimal communication system parameter p min under the evaporation duct and tropospheric scatter mixed channel.; The transmitting end and the receiving end configure antennas and conduct system communication according to the optimal communication system parameter p min to perform antenna configuration and system communication, so as to optimize the communication system parameters under the hybrid channel and reduce the microwave propagation path loss.

[0068] Among them, the global optimization algorithm includes the global traversal algorithm, genetic algorithm, particle swarm optimization algorithm, repulsive particle swarm algorithm, and whale algorithm, and the maximum number of iterations j is set max ; The termination condition is that when the transmitting antenna height h t and the receiving antenna height h r take values in the range of 2 - 25m, and the electromagnetic wave frequency f takes values in the range of 1 - 20GHz. If when p i = p min at this time the value is the smallest or the number of iterations reaches j max , then p min is the optimal communication system parameter under the hybrid channel.

[0069] In this solution, the horizontal propagation distance x takes values in the range of 0 - 500km, the vertical propagation height z takes values in the range of 0 - 500m; the evaporation duct height δ t takes values in the range of 0 - 50m, and the antenna type is omnidirectional antenna and directional antenna; different transmitting antenna heights h t take values in the range of 2 - 25m; different receiving antenna heights h r take values in the range of 2 - 25m; the electromagnetic wave frequency f takes values in the range of 1 - 20GHz.

[0070] In an embodiment of the present invention, an omnidirectional antenna is adopted, x0 is the electromagnetic wave propagation communication distance of 300km, the transmitting antenna height h t is 10m, the receiving antenna height h r is 10m, and the electromagnetic wave frequency f is 5GHz, that is, p1 = [10 10 5]; using the global reanalysis meteorological data of the European Centre for Medium-Range Weather Forecasts, the air temperature 2m above the sea surface and the absolute humidity 2m above the sea surface are input into the atmospheric absorption attenuation model, and the atmospheric absorption loss PL gas = 3dB is obtained; using the global reanalysis meteorological data of the climate system of the European Centre for Medium-Range Weather Forecasts, including atmospheric pressure, sea surface temperature, air temperature 2m above the sea surface, absolute humidity 2m above the sea surface, and wind speed component 10m above the sea surface, the meteorological data is input into the NPS evaporation duct prediction model, and the evaporation duct height δ0 is obtained as 13m.

[0071] Substitute the electromagnetic wave propagation distance x0 and p1 = [10 10 5] into the parabolic equation model, and calculate to obtain PL duct (p1) = 259.20dB, PLtrop L(p1) = 228.20 dB dif = 31 dB > 18 dB. At this time, the path loss value PL(p1) under the evaporation duct and tropospheric scatter hybrid channel duct,trop L(p1) = 228.20 dB Figure 3 is a schematic diagram of the path loss of the evaporation duct channel, tropospheric scatter channel, and hybrid channel when the evaporation duct height is 13 m, the transmitting antenna height is 10 m, the receiving antenna height is 10 m, and the electromagnetic wave frequency is 5 GHz.

[0072] This example uses a global traversal algorithm to solve a set of p that minimizes L min , Figure 4 is a schematic diagram of the path loss of the evaporation duct and tropospheric scatter hybrid channel varying with the transmitting antenna height, receiving antenna height, and electromagnetic wave frequency.

[0073] When the propagation distance is 300 km and the evaporation duct height is 13 m, the optimal transmitting antenna height under the evaporation duct and tropospheric scatter hybrid channel is 3 m, the optimal receiving antenna height is 3 m, and the optimal electromagnetic wave frequency is 15 GHz, that is, p min = [3 3 15] is the optimal parameter of the communication system under this hybrid channel. Figure 5 is a schematic diagram of the path loss after parameter optimization under the evaporation duct and tropospheric scatter hybrid channel when the evaporation duct height is 13 m.

[0074] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application 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 recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A parameter optimization method based on a hybrid channel of evaporative waveguide and tropospheric scattering, characterized in that: include: A hybrid channel propagation model between the transmitting end and the receiving end is constructed using the relevant parameters of the signal transmitting end and the signal receiving end on the sea surface; the field intensity distribution of the electromagnetic field under the evaporation waveguide channel and the field intensity distribution of the electromagnetic field under the tropospheric scattering channel are determined using the hybrid channel propagation model; wherein the relevant parameters include the refractive index of the evaporation waveguide environment medium and the refractive index of the tropospheric scattering environment medium; Based on the field intensity distribution of the electromagnetic field under the evaporation waveguide channel and the field intensity distribution of the electromagnetic field under the tropospheric scattering channel, the path loss value under the evaporation waveguide channel and the path loss value under the tropospheric scattering channel under the system parameters are calculated; The path loss value of the evaporation duct and tropospheric scattering mixed channel is determined by the path loss value of the evaporation duct channel and the path loss value of the tropospheric scattering signal; Establishing an objective function related to system parameters through the path loss value in the evaporation duct and tropospheric scatter hybrid channel; Combining the global optimization algorithm and the preset termination condition, solving the system parameters that minimize the value of the objective function as the optimal communication system parameters under the evaporative waveguide and tropospheric scatter hybrid channel; The transmitting end and the receiving end perform antenna configuration and system communication according to the optimal communication system parameters.

2. The parameter optimization method based on the evaporative waveguide and tropospheric scattering hybrid channel according to claim 1 is characterized in that: The hybrid channel propagation model is expressed as: Where k0 is the free space wave number of the electromagnetic wave; i is the imaginary unit; n(x,z) duct is the refractive index of the evaporation waveguide environment, n(x,z) trop is the refractive index of the tropospheric scattering environment medium; x represents the horizontal propagation distance in km; z represents the height from the sea surface in m; u(x,z) duct is the electromagnetic field intensity distribution under the evaporation waveguide channel calculated using the narrow-angle parabolic equation, u(x,z) trop It is the field intensity distribution of the electromagnetic field under the tropospheric scattering channel calculated using the wide-angle parabolic equation model.

3. The parameter optimization method based on the evaporative waveguide and tropospheric scattering hybrid channel according to claim 1 is characterized in that: The refractive index of the evaporation waveguide environment medium n(x,z) duct The atmospheric pressure, sea surface temperature, air temperature, absolute humidity and wind speed components measured by marine environment detection equipment are input into the evaporation duct prediction model for calculation; the evaporation duct model includes the NPS model, the PJ model, the MGB model and the Babin model; The refractive index of the tropospheric scattering environment medium n(x,z) trop It is calculated by inputting meteorological parameters such as atmospheric pressure, absolute temperature, absolute humidity, etc. measured by tropospheric detection equipment into the atmospheric refractive index model.

4. The parameter optimization method based on the evaporative waveguide and tropospheric scattering hybrid channel according to claim 1 is characterized in that: The calculation obtains the path loss value of the evaporation waveguide channel and the path loss value of the tropospheric scattering signal under the system parameters, and the specific formula is: Among them, PL duct (p i ) is the path loss value of the evaporation waveguide channel, PL trop (p i ) is the path loss value in the tropospheric scatter channel; is the electromagnetic field intensity distribution u(x,z) under the evaporation waveguide channel duct and system parameter p i Related field strength distribution; is the field intensity distribution u(x,z) of the electromagnetic field under the tropospheric scatter channel trop and system parameter p i Related field strength distribution; PL gas is the atmospheric absorption loss value; λ represents the wavelength of electromagnetic wave, in m; p i represents the system parameters of the evaporation duct and tropospheric scattering hybrid channel, specifically: p i =[h t ,h r ,f]; where h t Indicates the height of the transmitting antenna, in meters; h r represents the height of the receiving antenna, in meters; f represents the frequency of the electromagnetic wave, in GHz; δ t is the atmospheric environment of the evaporation duct at different heights, in m; δ0 is the actual evaporation duct height, in m; x0 is the actual electromagnetic wave propagation distance, in km; PL gas is the atmospheric absorption loss value, in dB.

5. The parameter optimization method based on the evaporative waveguide and tropospheric scattering hybrid channel according to claim 1 is characterized in that: Atmospheric absorption loss value PL gas The calculation formula is as follows: PL gas =(γ o +g w )×x (5) Among them, γ o is the oxygen absorption attenuation rate, in dB / km, γ w is the water vapor absorption attenuation rate, in dB / km, and the relevant calculation formula is as follows: t air is the air temperature 2 meters above the sea surface, and hum is the absolute humidity 2 meters above the sea surface.

6. The parameter optimization method based on the evaporative waveguide and tropospheric scattering hybrid channel according to claim 1 is characterized in that: The path loss value of the evaporation duct and tropospheric scattering mixed channel is determined by the path loss value of the evaporation duct channel and the path loss value of the tropospheric scattering signal, specifically: L dif =PL duct (p i )-PL trop (p i ) (7) Among them, L dif is the difference between the path loss of the evaporative waveguide channel and the path loss of the tropospheric scattering channel, PL duct (p i ) is the path loss value of the evaporation waveguide channel, PL trop (p i ) is the path loss value of the tropospheric scatter signal, PL duct,trop (p i ) is the path loss value in the mixed channel of evaporative duct and tropospheric scatter.

7. The parameter optimization method based on the evaporative waveguide and tropospheric scattering hybrid channel according to claim 1 is characterized in that: The objective function related to the system parameters is established by the path loss value under the evaporation duct and tropospheric scattering hybrid channel, which is expressed as: Among them, p i is the system parameter, PL duct,trop (p i ) is the path loss value of the mixed channel of evaporative duct and tropospheric scatter, is the objective function, δ t is the atmospheric environment of the evaporation waveguide at different heights, δ0 is the actual evaporation waveguide height, x represents the horizontal propagation distance, and x0 is the actual electromagnetic wave propagation distance.

8. The parameter optimization method based on the evaporative waveguide and tropospheric scattering hybrid channel according to claim 1 is characterized in that: The global optimization algorithm includes global traversal algorithm, genetic algorithm, particle swarm optimization algorithm, repulsive particle swarm optimization algorithm and whale algorithm, and sets the maximum number of iterations j max ; The termination condition is at the transmitting antenna height h t , receiving antenna height h r The value is 2-25m, and the electromagnetic wave frequency f is in the range of 1-20GHz. i =p min hour The value of is the smallest or the number of iterations reaches j max , then p min are the optimal communication system parameters under mixed channels.

9. A communication system, characterized in that: The communication system optimizes the communication parameters of the transmitting end and the receiving end by using the parameter optimization method based on the evaporative waveguide and tropospheric scatter hybrid channel according to any one of claims 1 to 8.

10. A computer-readable storage medium, wherein a computer program is stored in the medium; characterized in that: When the computer program is executed by a processor, the parameter optimization method based on the evaporation waveguide and tropospheric scatter hybrid channel according to any one of claims 1 to 8 is implemented.

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