Wide-spectrum light beam atmospheric transmission thermal halo effect simulation method and system

Abstract

The invention belongs to the field of wide-spectrum laser atmospheric transmission evaluation, and particularly relates to a wide-spectrum light beam atmospheric transmission thermal halo effect simulation method and system. The method comprises the steps of simulating linear effect complex amplitudes at different transmission distances under a linear effect based on transmission scene parameters; calculating light intensity distribution factors at different transmission distances based on simulation results of linear effect complex amplitudes at different transmission distances; based on the transmission scene parameters and the light intensity distribution factors at different transmission distances, phase disturbance caused by the thermal halo effect is calculated; on the basis of phase disturbance caused by the thermal halo effect, complex amplitudes at focal lengths at different moments are simulated; and calculating the long-time average light intensity distribution based on the analogue simulation results of the complex amplitudes at the focal lengths at different moments. According to the method, the wide-spectrum laser is equivalent to the single-wavelength laser, and simulation of the atmospheric transmission thermal halo effect of the wide-spectrum light beam is achieved based on the light intensity distribution factor of the wide-spectrum light beam and the fluid mechanics equation set of interaction between the wide-spectrum light beam and the atmosphere.

Description

Technical Field

[0001] This invention belongs to the field of broadband laser atmospheric transmission evaluation, and specifically relates to a simulation method and system for the thermal corona effect of broadband laser atmospheric transmission. Background Technology

[0002] The atmospheric transmission thermal corona effect of high-power lasers refers to the disturbance in the atmospheric refractive index distribution along the optical path caused by the absorption of the laser beam's energy. This disturbance, in turn, affects the propagation of the laser beam. The thermal corona effect is closely related to the wavelength characteristics of the laser beam; different wavelengths of lasers exhibit varying degrees of thermal corona effect under the same atmospheric conditions.

[0003] In recent years, with the development of fiber optic light source manufacturing and beam combining technologies, the thermal corona effect of broadband beam atmospheric transmission has become a hot research topic in the field of laser atmospheric transmission assessment. A significant characteristic of broadband laser sources is that power is distributed across multiple wavelengths. All wavelengths of the broadband laser collectively heat the atmosphere, causing a thermal corona effect, which makes the thermal corona effect mechanism different between broadband beams and single-wavelength beams. However, simulation methods for the thermal corona effect of broadband beam atmospheric transmission are lacking in engineering applications such as laser system optimization and photovoltaic power plant site assessment. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a simulation method for the atmospheric transmission thermal corona effect of broadband beams. By constructing a light intensity distribution factor for the broadband beam, the interaction process between the broadband beam and the atmosphere is equated to the interaction process between a single wavelength and the atmosphere. Based on the hydrodynamic equations of the interaction between the broadband beam and the atmosphere, a two-dimensional distribution of atmospheric refractive index disturbance and phase disturbance caused by thermal corona effect at different transmission distances is established. This enables the simulation of complex amplitude at different focal lengths and obtains the long-term average light intensity distribution of the beam spot at the focal length of the broadband beam's atmospheric transmission.

[0005] The first objective of this invention is to provide a method for simulating the atmospheric transmission thermal corona effect of broadband beams, comprising: Based on transmission scenario parameters, the complex amplitude of linear effects at different transmission distances under linear effects is simulated; Based on the simulation results of the linear effect complex amplitude at different transmission distances, the light intensity distribution factor at different transmission distances is calculated; Based on the transmission scenario parameters and the light intensity distribution factor at different transmission distances, the phase perturbation caused by the thermal corona effect is calculated. Based on the phase perturbation caused by thermal corona effect, the complex amplitude at the focal length at different times is simulated. Based on the simulation results of complex amplitude at different focal lengths, the long-term average light intensity distribution is calculated.

[0006] In a specific embodiment of the present invention, the transmission scene parameters include the power spectral density of the broadband beam, the atmospheric absorption coefficient of different wavelengths at different transmission distances, the atmospheric extinction coefficient of different wavelengths at different transmission distances, the focal length, the wind speed vector, and the complex amplitude of the light source at the equivalent wavelength.

[0007] In a specific embodiment of the present invention, simulating the complex amplitude of the linear effect at different transmission distances based on transmission scenario parameters includes: Calculate the equivalent wavelength based on the power spectral density of the broadband beam in the transmission scenario parameters; Based on the atmospheric extinction coefficients at different wavelengths at different transmission distances in the transmission scenario parameters, calculate the atmospheric transmittance at the equivalent wavelength at different transmission distances along the optical path. The focal length is segmented, and the complex amplitude distribution of the linear effect at different transmission distances is simulated based on the atmospheric transmittance at the equivalent wavelength along different transmission distances.

[0008] In a specific embodiment of the present invention, the formula for calculating the light intensity distribution factor is as follows:

[0009] in, Light intensity distribution factor, For equivalent wavelength, Indicates the laser transmission distance. Indicates focal length Divided into Section 1 The end of the segment, yes The transverse coordinate vector perpendicular to the light path. For the equivalent wavelength is The power spectral density of the light source, The equivalent wavelength is Beam propagation distance along the optical path z i Atmospheric transmittance at that location; Equivalent wavelength The beam travels a distance along the optical path The linear effect complex amplitude at the point.

[0010] In a specific embodiment of the present invention, the calculation of the phase perturbation caused by the thermal corona effect based on transmission scene parameters and light intensity distribution factors at different transmission distances includes: Based on the light intensity distribution factor at different transmission distances, as well as the power spectral density, atmospheric absorption coefficient and atmospheric transmittance at different wavelengths at different transmission distances, and wind speed vector in the transmission scene parameters, the refractive index perturbation at any time is calculated. Calculate the phase perturbation caused by the thermal corona effect based on the refractive index perturbation at any time.

[0011] In a specific embodiment of the present invention, the refractive index perturbation at any given time Calculate according to the following formula:

[0012] in, Indicates wavelength. It is the differential symbol. Indicates time Find the partial derivative. This represents the rate of change of refractive index relative to temperature. Indicates atmospheric temperature. This represents the average atmospheric density. This represents the wind speed vector perpendicular to the optical path. It is the specific heat capacity of atmosphere at constant pressure. It is the thermal conductivity coefficient. Let be the expression for the source power spectral density of the light beam. The maximum value of the power spectral distribution wavelength. This represents the minimum wavelength of the power spectral distribution. The distance the light beam travels along the optical path z i The expression for the atmospheric absorption coefficient at that location. The distance the light beam travels along the optical path z i The expression for atmospheric transmittance at a given location. is the light intensity distribution factor.

[0013] In a specific embodiment of the present invention, the calculation formula for the phase perturbation caused by the thermal corona effect is as follows:

[0014] in, This indicates that the optical transmission period is divided into equal intervals. Section 1 At the end of the segment, For any time The refractive index perturbation, For equivalent wavelength, , Indicates focal length Divided into Section 1 The end of the segment.

[0015] In a specific embodiment of the present invention, the calculation of the long-term average light intensity distribution based on the simulation results of the complex amplitude at different focal lengths includes: Based on the simulation results of the complex amplitude at the focal length at different times, the complex amplitude at the focal length is calculated; The average value of the square of the complex amplitude at the focal length over time is taken as the long-term average light intensity distribution.

[0016] The second objective of this invention is to provide a simulation system for the atmospheric transmission thermal corona effect of broadband beams, comprising: First simulation module: used to simulate the complex amplitude of linear effects at different transmission distances based on transmission scenario parameters; The first calculation module is used to calculate the light intensity distribution factor at different transmission distances based on the simulation results of the linear effect complex amplitude at different transmission distances. The second calculation module is used to calculate the phase perturbation caused by thermal coma based on transmission scene parameters and light intensity distribution factors at different transmission distances. The second simulation module is used to simulate the complex amplitude at the focal length at different times based on the phase perturbation caused by the thermal corona effect. The third calculation module is used to calculate the long-term average light intensity distribution based on the simulation results of the complex amplitude at different focal lengths.

[0017] In a specific embodiment of the present invention, the first simulation module includes a preprocessing module and an execution module; The preprocessing module is used to calculate the equivalent wavelength based on the power spectral density of the broadband beam in the transmission scene parameters; it is also used to calculate the atmospheric transmittance at different transmission distances along the optical path at the equivalent wavelength based on the atmospheric extinction coefficient at different wavelengths at different transmission distances in the transmission scene parameters. Execution module: used to segment the focal length and simulate the complex amplitude of the linear effect at different transmission distances along the optical path based on the atmospheric transmittance at the equivalent wavelength.

[0018] The beneficial effects of this invention are: This invention discloses a simulation method and system for atmospheric transmission thermal corona effect of broadband beams. Addressing the significant characteristic of broadband beam power distribution across multiple wavelengths, the method first calculates the complex amplitude of the linear effect under diffraction and attenuation by equating the broadband laser to a single-wavelength laser. Considering the varying strengths of the thermal corona effect at different wavelengths, a light intensity distribution factor for the broadband beam is further constructed. Based on this factor, the interaction between the broadband beam and the atmosphere is equated to the interaction between a single wavelength and the atmosphere. Furthermore, based on the hydrodynamic equations governing the interaction between the broadband beam and the atmosphere, a two-dimensional distribution of atmospheric refractive index disturbance and phase disturbance caused by thermal corona effect at different transmission distances is established to simulate the thermal corona effect of broadband beam atmospheric transmission. This simulation achieves the simulation of complex amplitude at different focal lengths and obtains the long-term average light intensity distribution of the beam spot at the focal length during broadband beam atmospheric transmission.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A flowchart of a simulation method for atmospheric transmission thermal corona effect of broadband beams according to an embodiment of the present invention is shown; Figure 2 The power spectral density distribution of a broadband beam source according to an embodiment of the present invention is shown; Figure 3 The diagram shows atmospheric extinction coefficient data and atmospheric transmittance data according to an embodiment of the present invention; wherein, Figure 3 In the middle (a), the atmospheric extinction coefficients of the light beams at different wavelengths along different propagation distances of the optical path are shown. Figure 3 (b) represents the atmospheric transmittance at a wavelength of 1060 nm at different transmission distances along the optical path; Figure 4 The complex amplitude distribution of the light source at the equivalent wavelength according to an embodiment of the present invention is shown, wherein... Figure 4 In the middle (a), the amplitude distribution of the light source at an equivalent wavelength of 1060 nm is shown. Figure 4 (b) shows the phase distribution at an equivalent wavelength of 1060 nm; Figure 5 The light intensity distribution factors at different transmission distances according to embodiments of the present invention are shown, wherein, Figure 5 In the diagram (a), the light intensity distribution factor is the light intensity distribution factor over a transmission distance of 0.1 km. Figure 5 In the middle (b), the light intensity distribution factor is the light intensity distribution factor over a transmission distance of 1.4 kilometers. Figure 5 In the diagram, (c) represents the light intensity distribution factor over a transmission distance of 2.8 kilometers. Figure 5 In the middle (d), the light intensity distribution factor is the light intensity distribution factor over a transmission distance of 5.0 kilometers; Figure 6 Atmospheric absorption coefficient data according to an embodiment of the present invention are shown; Figure 7 The phase perturbation caused by thermal corona effect at different transmission distances according to embodiments of the present invention is illustrated, wherein, Figure 7 In (a), the phase disturbance caused by thermal corona effect at a transmission distance of 0.1 km and a time of 52.4 ms is shown. Figure 7 (b) shows the phase disturbance caused by thermal corona effect at a transmission distance of 1.4 km and a time of 52.4 ms. Figure 7 In the middle (c), the phase disturbance caused by the thermal corona effect is at a transmission distance of 2.8 km and a time of 52.4 ms. Figure 7 In the middle (d), the phase disturbance caused by the thermal corona effect at a transmission distance of 5 kilometers and a time of 52.4 milliseconds is represented. Figure 8 The diagram shows the long-term average light intensity distribution of the spot at the atmospheric transmission focal length of the broadband beam according to an embodiment of the present invention. Figure 9 A framework diagram of a broadband beam atmospheric transport thermal corona effect simulation system according to an embodiment of the present invention is shown. In the diagram: 10, First simulation module; 20, First calculation module; 30, Second calculation module; 40, Second simulation module; 50, Third calculation module. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, a simulation method for atmospheric transmission thermal corona effect of broadband beams according to certain embodiments of the present invention includes: S1. Based on the transmission scenario parameters, the broadband light source is equivalent to a single-wavelength light source, and the complex amplitude of the linear effect at different transmission distances under the linear effect is simulated. S2. Based on the simulation results of the linear effect complex amplitude at different transmission distances, calculate the light intensity distribution factor at different transmission distances; S3. Based on the transmission scenario parameters and the light intensity distribution factor at different transmission distances, calculate the phase perturbation caused by the thermal corona effect; S4. Based on the phase perturbation caused by thermal corona effect, simulate the complex amplitude at the focal length at different times; S5. Based on the simulation results of the complex amplitude at different focal lengths, calculate the long-term average light intensity distribution.

[0024] In some embodiments of the present invention, in step S1, the transmission scene parameters include the power spectral density of the broadband beam, the atmospheric absorption coefficient of different wavelengths at different transmission distances, the atmospheric extinction coefficient of different wavelengths at different transmission distances, the focal length, the wind speed vector, and the complex amplitude of the light source at the equivalent wavelength.

[0025] In some embodiments of the present invention, step S1 includes: S1-1. Calculate the equivalent wavelength based on the power spectral density of the broadband beam in the transmission scenario parameters; the power spectral density of the light source is... equivalent wavelength The expression is shown in equation (1): (1) in, Indicates wavelength. It is the minimum wavelength value. That is the maximum wavelength value.

[0026] S1-2. Based on the atmospheric extinction coefficients at different wavelengths at different transmission distances in the transmission scenario parameters, calculate the atmospheric transmittance at the equivalent wavelength along different transmission distances along the optical path; where the atmospheric extinction coefficients corresponding to different wavelengths are... Atmospheric transmittance at equivalent wavelengths at different transmission distances The calculation formula is shown in formula (2): (2) In the formula, Indicates exponentiation. Indicates the laser transmission distance. Indicates focal length Divided into Section 1 The end of the segment.

[0027] S1-3. Divide the focal length into segments and simulate the complex amplitude distribution of the linear effect at different transmission distances along the optical path based on the atmospheric transmittance at the equivalent wavelength.

[0028] focal length Divided into part, For the first The endpoint of the segment is determined based on the Fresnel diffraction theory of light waves under the paraxial approximation. The specific simulation calculation formula is shown in equation (3): (3) In equation (3), yes The transverse coordinate vector perpendicular to the light path. For the equivalent wavelength is Beam propagation distance along the optical pathz i Atmospheric transmittance at that location , For the equivalent wavelength is The beam of light at the transmission distance Linear effect complex amplitude at the point, , This represents the Fourier transform, where j is a complex number. Equivalent wavelength The beam of light at the transmission distance z Complex amplitude of the light source at 0.

[0029] In step S1, some embodiments of the present invention equate a broadband light source to a single-wavelength light source in order to simulate the complex amplitude of the linear effect at different transmission distances under the linear effect.

[0030] In some embodiments of the present invention, in step S2, the formula for calculating the light intensity distribution factor is as shown in equation (4): (4) In equation (4), Light intensity distribution factor, It represents the complex amplitude of the linear effect at different transmission distances; The power spectral density of the light source at the equivalent wavelength The value at that location, For the equivalent wavelength is Beam propagation distance along the optical path Atmospheric transmittance at that location.

[0031] In some embodiments of the present invention, step S3 includes: S3-1. Based on the light intensity distribution factor at different transmission distances, as well as the power spectral density, atmospheric absorption coefficient and atmospheric transmittance at different wavelengths at different transmission distances, and wind speed vector in the transmission scene parameters, calculate the refractive index disturbance at any time. S3-2. Calculate the phase perturbation caused by the thermal corona effect based on the refractive index perturbation at any time.

[0032] In some embodiments of the present invention, in step S3-1, during the calculation of the refractive index disturbance at any time, fluid dynamics theory is considered, and the calculation formula for the refractive index disturbance at any time is derived. The specific derivation process is as follows: According to fluid mechanics theory, the wavelength is Complex amplitude is The interaction between the beam of light and the atmosphere satisfies the fluid dynamics equations (5): (5) In equation (5), Indicates atmospheric temperature. and These are the average and disturbance values ​​of atmospheric density, respectively. and These are the average and disturbance values ​​of atmospheric pressure, respectively. This represents the wind speed vector perpendicular to the optical path. It is the specific heat capacity of atmosphere at constant pressure. It is the thermal conductivity coefficient. It is the ratio of specific heat at constant pressure to specific heat at constant volume.

[0033] Will Replace it with a function of the light intensity distribution factor, as shown in equation (6): (6) Under the isobaric approximation, substituting equation (6) into the above set of fluid dynamics equations (5), we obtain equation (7): (7) In equation (7), It is a wavelength of The refractive index disturbance caused by the beam of light.

[0034] The refractive index perturbation caused by the thermal corona effect of broadband beams is The integral over the wavelength is shown in equation (8): (8) Integrating equation (8) over the power spectral density wavelength range yields the formula for calculating the refractive index perturbation caused by the thermal corona effect at any given time, as shown in equation (9): (9) In equation (9), The refractive index disturbance is caused by the atmospheric transmission thermal corona effect of broadband beams. It represents the rate of change of refractive index relative to temperature.

[0035] Ignoring the differences in intensity distribution factors at different wavelengths, the intensity distribution factors at different wavelengths are... use If we replace it, then equation (9) becomes equation (10): (10) In equation (10), For any time The refractive index perturbation, This represents the rate of change of refractive index relative to temperature. Indicates atmospheric temperature. This represents the average atmospheric density. This represents the wind speed vector perpendicular to the optical path. It is the specific heat capacity of atmosphere at constant pressure. It is the thermal conductivity coefficient. Let be the expression for the source power spectral density of the light beam. The maximum value of the power spectral distribution wavelength. This represents the minimum wavelength of the power spectral distribution. The distance the light beam travels along the optical path z i The expression for the atmospheric absorption coefficient at a given location, that is, the atmospheric absorption coefficient of the light beam along different propagation distances along the optical path. The distance the light beam travels along the optical path z i Atmospheric transmittance at a certain point, that is, atmospheric transmittance of the light beam at different distances along the optical path.

[0036] In some embodiments of the present invention, during step S3-2, the phase perturbation process caused by the thermal corona effect, the phase perturbation caused by the thermal corona effect... The calculation formula is shown in equation (11): (11) In equation (11), This indicates that the optical transmission period is divided into equal intervals. Section 1 At the end of the segment, This is the equivalent wavelength.

[0037] In some embodiments of the present invention, in step S4, the simulation of the complex amplitude at different focal lengths is performed based on the Fresnel diffraction theory of light waves under the paraxial approximation, and the specific simulation calculation formula is shown in equation (12): (12) In equation (12), .

[0038] Phase perturbation caused by thermal halo effect at different times Substituting into equation (12), the focal length can be calculated. Complex amplitude at the location .

[0039] In some embodiments of the present invention, step S5 involves averaging the complex amplitude at the focal length over time as the long-term average light intensity distribution, as shown in equation (13).

[0040] (13) In steps S2-S5, some embodiments of the present invention consider the different strengths of thermal corona effects of lasers of different wavelengths. By constructing a light intensity distribution factor for a broadband beam, the interaction process between the broadband beam and the atmosphere is equivalent to the interaction process between a single wavelength and the atmosphere. However, in the simulation process, a two-dimensional distribution of atmospheric refractive index disturbance and phase disturbance caused by thermal corona effect at different transmission distances is established using a set of hydrodynamic equations based on the interaction between the broadband beam and the atmosphere. This enables the simulation of complex amplitude at the focal length at different times and obtains the long-term average light intensity distribution of the light spot at the atmospheric transmission focal length of the broadband beam.

[0041] Based on the broadband beam atmospheric transmission thermal corona effect simulation method provided in the above embodiments, a specific example of spectral beam atmospheric transmission thermal corona effect simulation is performed, and the specific process is as follows: Proceed to step S1: Figure 2 The power spectral density of the light source is shown. Data, minimum wavelength Nanometers, maximum wavelength Nanoscale; based on light source power spectral density The data was used to calculate the equivalent wavelength, which was found to be 1064 nanometers. Figure 3 (a) shows the atmospheric extinction coefficients for different wavelengths. , Figure 3 (b) shows the atmospheric transmittance at a wavelength of 1060 nm at different transmission distances.

[0042] Figure 4 (a) shows the complex amplitude of the light source at an equivalent wavelength of 1064 nm. The amplitude distribution, Figure 4 (b) shows the complex amplitude of the light source at an equivalent wavelength of 1064 nm. Phase distribution. Focal length. Kilometers are divided into 22 segments, namely The linear effect complex amplitude at different transmission distances along the optical path is simulated according to equation (3).

[0043] Proceed to step S2: Based on the simulation results of complex amplitude at different transmission distances obtained in step S1, and the light intensity distribution factor at different transmission distances calculated using equation (4), Figure 5 The light intensity distribution factor at different transmission distances is shown.

[0044] Proceed to step S3: Based on the light intensity distribution factor obtained in step S2, the atmospheric absorption coefficient at different transmission distances along the optical path, and the atmospheric transmittance of the beam at different transmission distances along the optical path, the thermal coma effect at any time is calculated using equation (10). The refractive index perturbation. In the calculation, the atmospheric absorption coefficient is as follows: Figure 6 As shown, the atmospheric temperature is 303.15 Kelvin, the wind speed in the X direction is 3 m / s, the wind speed in the Y direction is 0 m / s, and the laser is emitted continuously for 0.1 seconds, which is divided into 10 equal time intervals.

[0045] The phase perturbation at different times is calculated using equation (11). Figure 7 The phase perturbation caused by thermal corona effect at different transmission distances of 52.4 milliseconds is presented.

[0046] Proceed to step S4: Based on the phase perturbation caused by the thermal halo effect obtained in step S3, the complex amplitude at the focal length at different times is simulated according to equation (12); and the phase perturbation caused by the thermal halo effect at different times is substituted. The focal length can be calculated. Complex amplitude at the location .

[0047] Proceed to step S5: The long-term average light intensity distribution is obtained by calculating according to formula (13). The specific long-term average light intensity distribution See details Figure 8 .

[0048] like Figure 9 As shown, a broadband beam atmospheric transport thermal corona effect simulation system according to certain embodiments of the present invention includes: First simulation module 10: used to simulate the complex amplitude of linear effects at different transmission distances based on transmission scenario parameters; First calculation module 20: used to calculate the light intensity distribution factor at different transmission distances based on the simulation results of the linear effect complex amplitude at different transmission distances; The second calculation module 30 is used to calculate the phase perturbation caused by the thermal coma effect based on the transmission scene parameters and the light intensity distribution factor at different transmission distances. Second simulation module 40: used to simulate the complex amplitude at the focal length at different times based on the phase perturbation caused by thermal corona effect; The third calculation module 50 is used to calculate the long-term average light intensity distribution based on the simulation results of the complex amplitude at different focal lengths.

[0049] In some embodiments of the present invention, the first simulation module 10 includes a preprocessing module and an execution module; The preprocessing module is used to calculate the equivalent wavelength based on the power spectral density of the broadband beam in the transmission scene parameters; it is also used to calculate the atmospheric transmittance at different transmission distances along the optical path at the equivalent wavelength based on the atmospheric extinction coefficient at different wavelengths at different transmission distances in the transmission scene parameters. Execution module: used to segment the focal length and simulate the complex amplitude of the linear effect at different transmission distances along the optical path based on the atmospheric transmittance at the equivalent wavelength.

[0050] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions 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. A simulation method for atmospheric transmission thermal corona effect of broadband beams, characterized in that, include: Based on transmission scenario parameters, the complex amplitude of linear effects at different transmission distances under linear effects is simulated; Based on the simulation results of the linear effect complex amplitude at different transmission distances, the light intensity distribution factor at different transmission distances is calculated; Based on the transmission scenario parameters and the light intensity distribution factor at different transmission distances, the phase perturbation caused by the thermal corona effect is calculated. Based on the phase perturbation caused by thermal corona effect, the complex amplitude at the focal length at different times is simulated. Based on the simulation results of complex amplitude at different focal lengths, the long-term average light intensity distribution is calculated.

2. The simulation method for atmospheric transmission thermal corona effect of broadband beams according to claim 1, characterized in that, The transmission scenario parameters include the power spectral density of the broadband beam, the atmospheric absorption coefficient at different wavelengths at different transmission distances, the atmospheric extinction coefficient at different wavelengths at different transmission distances, the focal length, the wind speed vector, and the complex amplitude of the light source at the equivalent wavelength.

3. The simulation method for atmospheric transmission thermal corona effect of broadband beams according to claim 1, characterized in that, The simulation of the complex amplitude of the linear effect at different transmission distances based on transmission scenario parameters includes: Calculate the equivalent wavelength based on the power spectral density of the broadband beam in the transmission scenario parameters; Based on the atmospheric extinction coefficients at different wavelengths at different transmission distances in the transmission scenario parameters, calculate the atmospheric transmittance at the equivalent wavelength at different transmission distances along the optical path. The focal length is segmented, and the complex amplitude distribution of the linear effect at different transmission distances is simulated based on the atmospheric transmittance at the equivalent wavelength along different transmission distances.

4. The simulation method for atmospheric transmission thermal corona effect of broadband beams according to claim 1, characterized in that, The formula for calculating the light intensity distribution factor is as follows: in, Light intensity distribution factor, For equivalent wavelength, Indicates the laser transmission distance. Indicates focal length Divided into Section 1 The end of the segment, yes The transverse coordinate vector perpendicular to the light path. The equivalent wavelength is The power spectral density of the light source, The equivalent wavelength is Beam propagation distance along the optical path z i Atmospheric transmittance at that location; Equivalent wavelength The beam travels a distance along the optical path The linear effect complex amplitude at the point.

5. The simulation method for atmospheric transmission thermal corona effect of broadband beams according to claim 1, characterized in that, The calculation of phase perturbation caused by thermal corona effect based on transmission scene parameters and light intensity distribution factors at different transmission distances includes: Based on the light intensity distribution factor at different transmission distances, as well as the power spectral density, atmospheric absorption coefficient and atmospheric transmittance at different wavelengths at different transmission distances, and wind speed vector in the transmission scene parameters, the refractive index perturbation at any time is calculated. Calculate the phase perturbation caused by the thermal corona effect based on the refractive index perturbation at any time.

6. The simulation method for atmospheric transmission thermal corona effect of broadband beams according to claim 5, characterized in that, The refractive index perturbation at any given time Calculate according to the following formula: in, Indicates wavelength. It is the differential symbol. Indicates time Find the partial derivative. This represents the rate of change of refractive index relative to temperature. Indicates atmospheric temperature. This represents the average atmospheric density. This represents the wind speed vector perpendicular to the optical path. It is the specific heat capacity of atmosphere at constant pressure. It is the thermal conductivity coefficient. Let be the expression for the source power spectral density of the light beam. The maximum value of the power spectral distribution wavelength. This represents the minimum wavelength of the power spectral distribution. The distance the light beam travels along the optical path z i The expression for the atmospheric absorption coefficient at that location. The distance the light beam travels along the optical path z i The expression for atmospheric transmittance at a given location. is the light intensity distribution factor.

7. The simulation method for atmospheric transmission thermal corona effect of broadband beams according to claim 5, characterized in that, The formula for calculating the phase perturbation caused by the thermal corona effect is as follows: in, This indicates that the optical transmission period is divided into equal intervals. Section 1 At the end of the segment, For any time The refractive index perturbation, For equivalent wavelength, , Indicates focal length Divided into Section 1 The end of the segment.

8. A simulation method for atmospheric transmission thermal corona effect of broadband beams according to any one of claims 1-7, characterized in that, The simulation results based on the complex amplitude at different focal lengths are used to calculate the long-term average light intensity distribution, including: Based on the simulation results of the complex amplitude at the focal length at different times, the complex amplitude at the focal length is calculated; The average value of the square of the complex amplitude at the focal length over time is taken as the long-term average light intensity distribution.

9. A simulation system for atmospheric transmission thermal corona effect of broadband beams, characterized in that, include: First simulation module: used to simulate the complex amplitude of linear effects at different transmission distances based on transmission scenario parameters; The first calculation module is used to calculate the light intensity distribution factor at different transmission distances based on the simulation results of the linear effect complex amplitude at different transmission distances. The second calculation module is used to calculate the phase perturbation caused by thermal coma based on transmission scene parameters and light intensity distribution factors at different transmission distances. The second simulation module is used to simulate the complex amplitude at the focal length at different times based on the phase perturbation caused by the thermal corona effect. The third calculation module is used to calculate the long-term average light intensity distribution based on the simulation results of the complex amplitude at different focal lengths.

10. A simulation system for atmospheric transmission thermal corona effect of broadband beams according to claim 9, characterized in that, The first simulation module includes a preprocessing module and an execution module; The preprocessing module is used to calculate the equivalent wavelength based on the power spectral density of the broadband beam in the transmission scene parameters; it is also used to calculate the atmospheric transmittance at different transmission distances along the optical path at the equivalent wavelength based on the atmospheric extinction coefficient at different wavelengths at different transmission distances in the transmission scene parameters. Execution module: used to segment the focal length and simulate the complex amplitude of the linear effect at different transmission distances along the optical path based on the atmospheric transmittance at the equivalent wavelength.

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