A method and device for simulating near space atmospheric ultraviolet radiation

Abstract

The application discloses a near space atmospheric ultraviolet radiation simulation method and device, and belongs to the field of radiation characteristic modeling. The method comprises the following steps: calculating the transmission attenuation of incident solar ultraviolet radiation and deducing the photoionization process to obtain the solar irradiance distribution and photoelectron generation rate source function of each height layer; performing energy spectrum solving and chemical equilibrium calculation on the atmospheric electron transport and component evolution process according to the photoelectron generation rate source function to obtain the electron energy flux spectrum and chemical composition number density distribution of different height layers; calculating and correcting the ultraviolet light emission process and strong absorption spectral line coupling effect of different mechanisms according to the electron energy flux spectrum to obtain the final luminophore emissivity of all spectral bands; and performing spectral expansion and integrated synthesis calculation on the spectral band integral emission and full-path radiation transmission process according to the luminophore emissivity to obtain the total ultraviolet spectral radiation luminance at the detector end. The application can improve the accuracy of near space ultraviolet radiation simulation.

Description

Technical Field

[0001] This invention relates to the field of radiation characteristic modeling technology, and in particular to a method and apparatus for simulating near-space atmospheric ultraviolet radiation. Background Technology

[0002] Given the increasing demands for near-space security, refined space weather forecasting and spacecraft flight support, and full-altitude climate change research, near-space detection technology is rapidly developing. The ultraviolet (UV) spectral band, on the one hand, reflects the coupling between the ionosphere and the neutral atmosphere, and on the other hand, can maximally shield against ground interference in the solar blind zone, giving it irreplaceable advantages in near-space environmental perception. In recent years, it has received increasing attention as a novel detection system. To select the optimal detection spectral band and support the design of detection algorithms, it is essential to understand the UV spectral radiation characteristics of the near-space atmosphere under arbitrary environmental and detection conditions.

[0003] In related technologies, the simulation of ultraviolet radiation characteristics of the near-space environment usually adopts the low-level atmospheric radiative transfer model. These models are completely unable to describe non-equilibrium phenomena such as chemiluminescence in the ultraviolet spectrum of the near-space atmosphere. Furthermore, the existing non-equilibrium luminescence radiation models also have significant errors in the simulation results of strong absorption non-equilibrium luminescence spectral bands with multiple scattering coupling effects.

[0004] Therefore, there is an urgent need for a near-space atmospheric ultraviolet radiation simulation method and device to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a method and apparatus for simulating near-space atmospheric ultraviolet radiation, enabling high-precision simulation calculations of the spectral radiance in front of near-space ultraviolet detectors. The technical solution is as follows: On the one hand, a method for simulating near-space atmospheric ultraviolet radiation is provided, the method comprising: Based on the initial solar ultraviolet radiation irradiance and the preset solar ultraviolet extinction section library, the transmission attenuation solution and photoionization process of the incident solar ultraviolet radiation are calculated, and the solar irradiance distribution and photoelectron generation rate source function of each altitude layer are obtained. Based on the photoelectron generation rate source function, the pre-set electron collision reaction cross section library, and the chemical reaction database, the energy spectrum solution and chemical equilibrium calculation of atmospheric electron transport and composition evolution processes are performed to obtain the electron energy flux spectrum and chemical composition number density distribution at different altitudes. Based on the electron energy flux spectrum and radiative transfer parameters, the coupling effect between ultraviolet luminescence processes with strong absorption spectral lines of different mechanisms is calculated and corrected to obtain the final emissivity of all spectral bands after coupled multiple scattering. Based on the emissivity of the luminescent body, standard spectral line shape data, and scattered radiation source terms, the spectral integral emission and the whole-path radiative transfer process are calculated by spectral expansion and integrated synthesis to obtain the total ultraviolet spectral radiance at the detector end.

[0006] On the other hand, a near-space atmospheric ultraviolet radiation simulation device is provided, the device comprising: The first calculation module is used to perform transmission attenuation calculation and photoionization process deduction of incident solar ultraviolet radiation based on the initial solar ultraviolet radiation irradiance and the preset solar ultraviolet extinction section library, and obtain the solar irradiance distribution and photoelectron generation rate source function for each altitude layer. The second calculation module is used to perform energy spectrum calculation and chemical equilibrium calculation on atmospheric electron transport and composition evolution processes based on the photoelectron generation rate source function, the preset electron collision reaction cross section library and chemical reaction database, so as to obtain the electron energy flux spectrum and chemical composition number density distribution at different altitudes. The third calculation module is used to calculate and correct the coupling effect between ultraviolet luminescence processes with strong absorption spectral lines of different mechanisms based on the electron energy flux spectrum and radiative transfer parameters, so as to obtain the final emissivity of all spectral bands after coupling multiple scattering. The fourth calculation module is used to perform spectral expansion and integrated calculation of the spectral integral emission and the whole-path radiative transfer process based on the emissivity of the luminescent body, standard spectral line shape data and scattered radiation source terms, so as to obtain the total ultraviolet spectral radiance at the detector end.

[0007] On the other hand, a computer device is provided, the computer device including a memory and a processor, the memory for storing computer programs, and the processor for executing the computer programs stored in the memory to implement the steps of the near-space atmospheric ultraviolet radiation simulation method described above.

[0008] On the other hand, a computer-readable storage medium is provided, wherein a computer program is stored therein, and when the computer program is executed by a processor, it implements the steps of the above-described near-space atmospheric ultraviolet radiation simulation method.

[0009] On the other hand, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the near-space atmospheric ultraviolet radiation simulation method described above.

[0010] The technical solution provided by this invention can bring at least the following beneficial effects: First, this method solves for the atmospheric transport of solar ultraviolet radiation based on an extinction cross section library, outputting the source functions of photoelectron generation rates at various altitudes. Then, combining electron collision cross sections and chemical reaction rate parameters, it solves for the electron energy flux spectrum and excited-state component fractional density at all altitudes. Subsequently, it calculates the initial local bulk emissivity according to three types of luminescence mechanisms and iteratively corrects the strong self-absorption spectral lines by coupling multiple scattering. Finally, after spectral expansion, it synthesizes the total radiance received by the detector through an integrated radiative transport equation. This method achieves full-link self-consistent coupling of photoexcitation, electron collision excitation, and chemical kinetic processes, eliminating the systematic errors caused by the step-by-step superposition of traditional methods. The bidirectional iterative correction of strong self-absorption spectral lines improves the simulation accuracy of core spectral lines, and the integrated radiative transport framework ensures the synchronous solution of non-equilibrium luminescence and atmospheric scattering, providing highly reliable numerical support for near-space ultraviolet detection and atmospheric inversion. Attached Figure Description

[0011] 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.

[0012] Figure 1 This is a flowchart of a near-space atmospheric ultraviolet radiation simulation method provided by an embodiment of the present invention; Figure 2 This is a structural diagram of a near-space atmospheric ultraviolet radiation simulation device provided in an embodiment of the present invention; Figure 3 This is a hardware architecture diagram of a computer device provided in an embodiment of the present invention. Detailed Implementation

[0013] 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 some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0014] Please refer to Figure 1 The present invention provides a near-space atmospheric ultraviolet radiation simulation method, the method comprising: Step 100: Based on the initial solar ultraviolet radiation irradiance and the preset solar ultraviolet extinction section library, perform transmission attenuation calculation and photoionization process deduction of the incident solar ultraviolet radiation to obtain the solar irradiance distribution and photoelectron generation rate source function for each altitude layer. Step 102: Based on the photoelectron generation rate source function, the preset electron collision reaction cross section library and chemical reaction database, perform energy spectrum solution and chemical equilibrium calculation on the atmospheric electron transport and composition evolution process to obtain the electron energy flux spectrum and chemical composition number density distribution at different altitudes. Step 104: Based on the electron energy flux spectrum and radiative transfer parameters, the coupling effect between ultraviolet luminescence processes with strong absorption spectral lines of different mechanisms is calculated and corrected to obtain the final emissivity of all spectral bands after coupled multiple scattering. Step 106: Based on the emissivity of the luminescent body, the standard spectral line shape data, and the scattered radiation source term, perform spectral expansion and integrated synthesis calculations on the spectral integral emission and the whole-path radiative transfer process to obtain the total ultraviolet spectral radiance at the detector end.

[0015] In this embodiment of the invention, the method first solves for the atmospheric transport of solar ultraviolet radiation based on the extinction cross section library, outputting the source functions of photoelectron generation rates at various altitudes. Then, combining electron collision cross sections and chemical reaction rate parameters, it solves for the electron energy flux spectrum and excited-state component fractional density at all altitudes. Subsequently, it calculates the initial local bulk emissivity according to three types of luminescence mechanisms and iteratively corrects the strong self-absorption spectral lines by coupling multiple scattering. Finally, after spectral expansion, it synthesizes the total radiance received by the detector using an integrated radiative transport equation. This method achieves full-link self-consistent coupling of photoexcitation, electron collision excitation, and chemical kinetic processes, eliminating the systematic errors caused by the step-by-step superposition of traditional methods. The bidirectional iterative correction of strong self-absorption spectral lines improves the simulation accuracy of core spectral lines, and the integrated radiative transport framework ensures the synchronous solution of non-equilibrium luminescence and atmospheric scattering, providing highly reliable numerical support for near-space ultraviolet detection and atmospheric inversion.

[0016] The following description Figure 1 The execution method for each step is shown.

[0017] First, this embodiment constructs a library of three excitation mechanisms based on the excitation mechanism of near-space ultraviolet luminescence components: Solar Ultraviolet Extinction Section Library: This library compiles and organizes the spectral absorption sections and spectral ionization / dissociation sections of the three main neutral atmospheric components in near space, N2, O2, and O, within the spectral range of 1~180nm. These sections are used to measure extreme ultraviolet solar radiation irradiance, photoelectron generation rate, photoionization / dissociation rate, and direct fluorescence emission rate at various altitudes. Electron Collision Response Cross-Section Library: This library compiles and organizes electron excitation cross-sections, electron ionization / dissociation cross-sections, and electron-electron elastic collision cross-sections for the three main neutral atmospheric components in near-space (N2, O2, and O) within the energy spectrum range of 1 eV to 1 GeV. It is used to calculate the electron energy flux spectrum, electron ionization / dissociation rate, and electron excitation rate at various altitudes under specified atmospheric top electron incident electron energy spectrum conditions. Chemical Reaction Rate Library: Compiled and edited + ( 2 P)O + ( 2 D) O + ( 4 S), N + N2 + O2 + NO + 、N2(A),N( 2 P), N( 2 D), O( 1 S), O( 1 D) Rate coefficients of various chemical reaction processes involved in the generation of near-space chemical products, used to calculate the number density of chemical products as altitude changes.

[0018] For step 100, the transmission attenuation of incident solar ultraviolet radiation and the photoionization process are calculated and derived based on the initial solar ultraviolet radiation irradiance and the preset solar ultraviolet extinction section library, so as to obtain the solar irradiance distribution and photoelectron generation rate source function of each altitude layer.

[0019] In this embodiment of the invention, the solar irradiance distribution and photoelectron generation rate source function for each altitude layer are obtained as follows: Based on atmospheric gas number density and solar ultraviolet extinction cross section data at different altitudes, the component extinction contribution of the solar radiation transmission path is calculated by layer-by-layer accumulation to obtain the total atmospheric optical thickness of all extinction channels at different altitudes.

[0020] Specifically, τ is the optical thickness of the solar radiation transmission path, calculated using the following formula: Where, τ l n represents the optical thickness caused by the l-th component. l (z) represents the number density of the l-th component at height z, σ lk photo This represents the absorption cross section or ionization / dissociation cross section of the l-th component in the k-th extinction channel.

[0021] Using the solar irradiance at the top of the atmosphere as the initial boundary, and based on the solar incident zenith angle and the total optical thickness of the atmosphere, the attenuation of the obliquely incident solar ultraviolet radiation is calculated to obtain the solar ultraviolet irradiance of all wavelength channels at different altitudes.

[0022] Specifically, the ionization of the neutral atmosphere by solar radiation in the extreme ultraviolet (EUV) spectrum is the primary mechanism of non-equilibrium radiation in near space. Therefore, the solar ultraviolet irradiance reaching each altitude layer is first calculated using the following formula: Where, λ i Let z be the i-th wavelength channel, z be the altitude, and μ be the wavelength. s =cosθ s θ s θ is the angle of incidence of the sun at the zenith; F is the angle of incidence of the sun at the zenith. s When the zenith angle is incident on the atmosphere and transmitted to a height z, λ i Solar irradiance at wavelength, where F0 is the solar irradiance at the top of the atmosphere.

[0023] Based on the solar ultraviolet radiation irradiance, ionization channel cross-section, and photon energy parameters at each altitude level, the photoionization yield process is quantitatively calculated channel by channel to obtain the photoelectron generation rate and electron energy corresponding to each ionization channel.

[0024] Specifically, the photoelectron generation rate is calculated using the solar ultraviolet radiation irradiance at each altitude level, using the following formula: Among them, S lki This represents λ at height z. i The rate at which radiation of wavelength E affects the rate at which the l-th component produces electrons through the k-th ionization channel. i For λ i Photon energy at wavelength.

[0025] At the same altitude level, the photoelectron generation rates of all ionization channels in the same energy range are summed to obtain the photoelectron generation rate source function used to characterize the electron energy resolution at different altitude levels.

[0026] Specifically, due to the different ionization channels requiring ionization energy E lk The energies of the electrons produced by each ionization channel are different, therefore the energies of the electrons produced by each ionization channel are also different. For all S channels that produce electrons with energy E... lki Summing these values ​​yields the photoelectron generation rate source function S(z,E) at height z, which is the key input to the electron energy flux spectrum algorithm.

[0027] Then, for step 102, based on the photoelectron generation rate source function, the preset electron collision reaction cross section library and chemical reaction database, the energy spectrum solution and chemical equilibrium calculation of the atmospheric electron transport and composition evolution process are performed to obtain the electron energy flux spectrum and chemical composition number density distribution at different altitudes.

[0028] In this embodiment of the invention, the electron energy flux spectrum and chemical composition number density distribution of each height layer are obtained as follows: Based on the electron energy range and electron collision cross section data, the electron energy spectrum calculation system is discretized and initial parameters are matched to obtain a discrete energy spectrum parameter set. Based on the losses of electrons when they collide with electrons and atmospheric gases, the electron migration contribution between different energy spectral intervals is calculated and summarized to obtain the electron conversion rate matrix for each energy spectral interval. Based on the energy loss path during electron collisions, the net electron energy loss of each energy spectral interval is quantitatively calculated to obtain the total electron loss rate corresponding to each energy spectral interval. Based on the generation rate of photoelectrons, the electron conversion rate and the total loss rate of the current altitude layer, the local electron energy balance equation is solved to obtain the discrete electron energy flux spectrum of the current altitude layer. Based on the discrete electron energy flux spectrum and atmospheric gas number density at the current altitude, the atmospheric component ionization process caused by electron collisions is calculated to obtain the ion generation rate caused by electron collisions at the current altitude. The continuity equations for each ion and excited-state chemical composition are solved in steady state based on the ion generation rate of the current layer to obtain the number density of ions and excited-state chemical composition of atmospheric gases at the current altitude. Using the incident electron energy spectrum at the top of the atmosphere as the initial boundary, the electron energy spectrum distribution and chemical composition number density are calculated iteratively from top to bottom to obtain the electron energy flux spectrum and chemical composition number density distribution of the entire altitude layer.

[0029] Specifically, G nm K is the rate at which an electron in the m-th energy interval is converted into an electron in the n-th energy interval. n The total electron loss rate for the nth energy spectral interval is calculated using the following expressions: Where, n e For electron number density, L m Let δ be the rate of electron loss in the m-th energy spectral interval due to electron-electron collisions. nm Let ΔE be the probability of transitioning from the m-th energy spectral interval to the n-th energy spectral interval. mn represents the energy bandwidth of the m-th spectral interval; l Let σ be the number density of the l-th gas component in the atmosphere. lm Let A be the collision loss cross section of the electron in the m-th energy spectral interval on the l-th gas. l nm L represents the probability that electron energy is converted to the nth energy spectral interval during the collision loss described above. n Let ΔE be the rate of electron loss in the nth energy spectral interval due to electron-electron collisions. n σ represents the energy bandwidth of the nth spectral interval; ln Let A be the collision loss cross section of the electron in the nth energy spectral interval on the lth gas. l nn The probability that an electron in the nth energy interval collides with the lth gas and is reionized to produce an electron in the nth energy interval.

[0030] This embodiment uses the local electron exchange equilibrium assumption to solve the electron energy transport equation, and derives the following formula for calculating the electron energy flux spectrum: Where, Φ n Let S(z,E) be the total electron energy flux within the nth energy spectral interval at height z. n E represents the photoelectron generation rate within the nth energy spectral interval at height z. n The median electron energy of the nth spectral interval; Using the result just obtained By combining the cross sections related to ionization / dissociation channels in the electron collision reaction cross section library, the ionization / dissociation rates of each neutral component in the current layer caused by electron collisions are calculated.

[0031] Specifically, for each energy interval, the electron flux is multiplied by the ionization cross-section of each component, and then integrated over the energy to obtain the total ionization / dissociation rate of each component. These rates will serve as source terms in the chemical composition number density evolution equation.

[0032] Combining the output ionization / dissociation generation rate with other known chemical generation pathways (such as photochemistry, charge exchange, etc.), within the current altitude layer, targeting O + (²P), O + (²D), O + ( 4 S), N + N2 + O2 + NO +Various chemical products, including N2(A), N(²P), N(²D), O(¹S), and O(¹D), are used to establish continuity equations for each product (i.e., production rate = loss rate, with steady-state assumptions). Loss terms include spontaneous emission and quenching through chemical reactions with other components. These equations are solved using reaction rate coefficients from a chemical reaction rate library to obtain the number density of each chemical product.

[0033] Finally, when calculating the distribution of electron energy flux spectrum with altitude, the incident electron energy flux spectrum at the top of the atmosphere is used as the initial value, and the calculation is performed layer by layer downwards from the first layer of atmosphere close to the top of the atmosphere until the set minimum altitude is reached.

[0034] For step 104, based on the electron energy flux spectrum and radiative transfer parameters, the coupling effect between ultraviolet luminescence processes with strong absorption spectral lines of different mechanisms is calculated and corrected to obtain the final emissivity of all spectral bands after coupled multiple scattering.

[0035] In this embodiment of the invention, O, N, H, N2, O2, NO, and N2 are used. + A local emission source function algorithm was constructed for each height layer using 31 spectral lines / bands of 7 main emission components to calculate the bulk emissivity of each spectral line / band at each height layer.

[0036] Based on the luminescence mechanism, they are constructed in three categories: Based on the solar ultraviolet irradiance at different altitudes, the total density of luminescent components, and fluorescence luminescence parameters, the local luminescence intensity of solar fluorescence excitation bands was quantitatively calculated, yielding the preliminary bulk emissivity of solar fluorescence. Among them, J i (z) represents the bulk emissivity of the i-th solar fluorescence spectral line / band at altitude z, g i (z) represents the fluorescence emission factor of this band at height z, and n(z) represents the total density of the luminescent components at height z.

[0037] Based on the electron energy flux spectrum, total density of luminescent components, and electron excitation cross-section parameters at different altitudes, the local luminescence intensity of the electron collision instantaneous excitation band is integrally calculated to obtain the initial bulk emissivity of electron collision instantaneous luminescence: Among them, J i (z) represents the bulk emissivity of the spectral line / band emitted at the i-th electron collision at height z, n(z) represents the total density of the luminescent components at height z, and σ i (z) represents the cross-section of the ith spectral line / band generated by the collision of electrons with the luminescent component, and Φ(z,E) represents the electron energy flux at height z with energy E.max To generate the maximum electron energy threshold for instantaneous luminescence upon collision, E i The minimum electron energy threshold required to produce instantaneous luminescence upon collision.

[0038] Based on the chemical component fraction density, chemical reaction rate coefficient, and spontaneous emission coefficient at different altitudes, the equilibrium process of the metastable components is calculated to obtain the initial bulk emissivity of metastable spontaneous emission: Among them, J i (z) represents the bulk emissivity of the i-th spontaneous emission spectral line / band at height z, A i n is the spontaneous emission coefficient of the i-th spectral line / band; i (z) represents the excited state number density corresponding to the i-th spontaneous emission spectral line / band. The formula for calculating this excited state number density is derived as follows: Where, p i For the chemical production rate of this excited state, A i n is the spontaneous emission coefficient of the excited state; j Let k be the number density of the j-th chemical component that can react chemically with the excited state. j This is the rate coefficient of a chemical reaction.

[0039] Based on three initial bulk emissivity, atmospheric absorption parameters, and initial values ​​of multiple scattering radiance, the luminescence source function of the strong self-absorption band is iteratively coupled and corrected to obtain the corrected final bulk emissivity.

[0040] Specifically, for metastable components with strong absorption, the bulk emissivity of spectral lines / bands at each altitude is affected by radiation at other altitudes; local luminescence and radiative transfer are tightly coupled. Therefore, an algorithm is designed to couple multiple scattering to correct the luminescence source function, modifying the above bulk emissivity calculation expression as follows: Among them, J i (z) represents the bulk emissivity of the i-th spontaneous emission spectral line / band at height z, A i n is the spontaneous emission coefficient of the i-th spectral line / band; j Let k be the number density of the j-th chemical component that can react chemically with the excited state. j The rate coefficient of this chemical reaction; p i For the chemical production rate of this excited state, B iLet J be the spontaneous absorption coefficient of the i-th emission spectral line / band, and I(z) be the average radiance of that spectral line / band at height z. Due to coupling, Newton's iterative method is used for calculation. The initial value of I(z) is the multiple scattering calculation result without considering non-equilibrium emission. The multiple scattering calculation result is updated according to the non-equilibrium emission calculation value until the iteration converges, and the final J is obtained. i (z).

[0041] This correction algorithm is only applied to three spectral lines: O 135.6nm, O 130.4nm, and H 121.6nm. The bulk emissivity calculations for other spectral lines and bands do not undergo this correction.

[0042] For step 106, based on the emissivity of the luminescent body, the standard spectral line shape data and the scattered radiation source term, the spectral integral emission and the whole path radiative transfer process are subjected to spectral expansion and integrated synthesis calculation to obtain the total ultraviolet spectral radiance at the detector end.

[0043] In this embodiment of the invention, the total ultraviolet spectral radiance is calculated as follows: The wavelength distribution pattern of each spectral band is matched and extracted according to the preset standard absorption spectrum library to obtain the normalized spectral line shape coefficient corresponding to each spectral band. Based on the final bulk emissivity of the spectral band and the normalized spectral line shape coefficient, the integral form of the luminescent source term is expanded and superimposed with the wavelength dimension to obtain the wavelength-resolved bulk emissivity of different height layers. Based on the spectral emissivity of different altitude layers, the preset atmospheric scattering radiation source function and detection path, and atmospheric extinction parameters, an integrated equation is constructed and the full-path integral is solved for the coupled radiation process of non-equilibrium emission and atmospheric scattering, so as to obtain the total ultraviolet spectral radiance at the detector receiver.

[0044] Specifically, for the bulk emissivity of the entire spectral line / band mentioned above, standard absorption spectral library data is introduced and converted into spectral bulk emissivity. The calculation formula is as follows: Among them, J λ (z) represents the spectral bulk emissivity at wavelength λ at height z, J i (z) represents the bulk emissivity of the i-th spontaneous emission spectral line / band at height z, and S(λ) is the normalization coefficient of this spectral line / band at wavelength λ. S is calculated based on data from the standard absorption spectral library.

[0045] The ultraviolet radiation sensed by the detector consists of both non-equilibrium emitted radiation and scattered radiation, which are synthesized through an integrated radiative transfer method. The calculation formula is as follows: Among them, Lλ λ represents the spectral radiance at wavelength λ sensed by the detector; s0 is the starting position of radiative transfer, and s1 is the ending position of the detector; J λ J is the spectral bulk emissivity at point s along the transmission path. λm Let τ be the spectral scattering radiation source function at point s along the transmission path; λ (s,s1) represents the optical thickness of the atmosphere at wavelength λ between s and s1.

[0046] Please refer to Figure 2 This invention provides a near-space atmospheric ultraviolet radiation simulation device, which includes: The first calculation module 200 is used to perform transmission attenuation calculation and photoionization process deduction of incident solar ultraviolet radiation based on the initial solar ultraviolet radiation irradiance and the preset solar ultraviolet extinction section library, so as to obtain the solar irradiance distribution and photoelectron generation rate source function of each altitude layer. The second calculation module 202 is used to perform energy spectrum calculation and chemical equilibrium calculation on the atmospheric electron transport and composition evolution process based on the photoelectron generation rate source function, the preset electron collision reaction cross section library and chemical reaction database, so as to obtain the electron energy flux spectrum and chemical composition number density distribution at different altitudes. The third calculation module 204 is used to calculate and correct the coupling effect between ultraviolet luminescence processes with strong absorption spectral lines of different mechanisms based on the electron energy flux spectrum and radiative transfer parameters, so as to obtain the final emissivity of all spectral bands after coupling multiple scattering. The fourth calculation module 206 is used to perform spectral expansion and integrated calculation of the spectral integral emission and the whole path radiative transfer process based on the emissivity of the luminescent body, standard spectral line shape data and scattered radiation source terms, so as to obtain the total ultraviolet spectral radiance at the detector end.

[0047] In this embodiment of the invention, the solar irradiance distribution and photoelectron generation rate source function for each altitude layer are obtained as follows: Based on atmospheric gas number density and solar ultraviolet extinction cross section data at different altitudes, the component extinction contribution of the solar radiation transmission path is calculated by layer-by-layer accumulation to obtain the total atmospheric optical thickness of all extinction channels at different altitudes. Using the solar irradiance at the top of the atmosphere as the initial boundary, and based on the solar incident zenith angle and the total optical thickness of the atmosphere, the attenuation of the obliquely incident solar ultraviolet radiation is calculated to obtain the solar ultraviolet irradiance of all wavelength channels at different altitudes. Based on the solar ultraviolet radiation irradiance, ionization channel cross-section and photon energy parameters of each altitude layer, the photoionization yield process is quantitatively calculated channel by channel to obtain the photoelectron generation rate and electron energy corresponding to each ionization channel. At the same altitude level, the photoelectron generation rates of all ionization channels in the same energy range are summed to obtain the photoelectron generation rate source function used to characterize the electron energy resolution at different altitude levels.

[0048] In this embodiment of the invention, the electron energy flux spectrum and chemical composition number density distribution of each height layer are obtained as follows: Based on the electron energy range and electron collision cross section data, the electron energy spectrum calculation system is discretized and initial parameters are matched to obtain a discrete energy spectrum parameter set. Based on the losses of electrons when they collide with electrons and atmospheric gases, the electron migration contribution between different energy spectral intervals is calculated and summarized to obtain the electron conversion rate matrix for each energy spectral interval. Based on the energy loss path during electron collisions, the net electron energy loss of each energy spectral interval is quantitatively calculated to obtain the total electron loss rate corresponding to each energy spectral interval. Based on the generation rate of photoelectrons, the electron conversion rate and the total loss rate of the current altitude layer, the local electron energy balance equation is solved to obtain the discrete electron energy flux spectrum of the current altitude layer. Based on the discrete electron energy flux spectrum and atmospheric gas number density at the current altitude, the atmospheric component ionization process caused by electron collisions is calculated to obtain the ion generation rate caused by electron collisions at the current altitude. The continuity equations for each ion and excited-state chemical composition are solved in steady state based on the ion generation rate of the current layer to obtain the number density of ions and excited-state chemical composition of atmospheric gases at the current altitude. Using the incident electron energy spectrum at the top of the atmosphere as the initial boundary, the electron energy spectrum distribution and chemical composition number density are calculated iteratively from top to bottom to obtain the electron energy flux spectrum and chemical composition number density distribution of the entire altitude layer.

[0049] In this embodiment of the invention, the final emissivity of the spectral band is obtained in the following manner: Based on the solar ultraviolet radiation irradiance, total density of luminescent components and fluorescence luminescence parameters at different altitudes, the local luminescence intensity of solar fluorescence excitation bands is quantitatively calculated to obtain the preliminary bulk emissivity of solar fluorescence. Based on the electron energy flux spectrum, total density of luminescent components, and electron excitation cross-section parameters at different altitudes, the local luminescence intensity of the electron collision instantaneous excitation band is integrally calculated to obtain the initial bulk emissivity of electron collision instantaneous luminescence. Based on the chemical component fraction density, chemical reaction rate coefficient and spontaneous emission coefficient at different altitudes, the equilibrium process of metastable components is calculated to obtain the initial bulk emissivity of metastable spontaneous emission. Based on three initial bulk emissivity, atmospheric absorption parameters, and initial values ​​of multiple scattering radiance, the luminescence source function of the strong self-absorption band is iteratively coupled and corrected to obtain the corrected final bulk emissivity.

[0050] In this embodiment of the invention, the total ultraviolet spectral radiance is calculated as follows: The wavelength distribution pattern of each spectral band is matched and extracted according to the preset standard absorption spectrum library to obtain the normalized spectral line shape coefficient corresponding to each spectral band. Based on the final bulk emissivity of the spectral band and the normalized spectral line shape coefficient, the integral form of the luminescent source term is expanded and superimposed with the wavelength dimension to obtain the wavelength-resolved bulk emissivity of different height layers. Based on the spectral emissivity of different altitude layers, the preset atmospheric scattering radiation source function and detection path, and atmospheric extinction parameters, an integrated equation is constructed and the full-path integral is solved for the coupled radiation process of non-equilibrium emission and atmospheric scattering, so as to obtain the total ultraviolet spectral radiance at the detector receiver.

[0051] In this embodiment of the invention, the total ultraviolet spectral radiance is calculated using the following formula: Among them, L λ λ represents the spectral radiance at wavelength λ sensed by the detector; s0 is the starting position of radiative transfer, and s1 is the ending position of the detector; J λ J is the spectral bulk emissivity at point s along the transmission path. λm Let τ be the spectral scattering radiation source function at point s along the transmission path; λ (s,s1) represents the optical thickness of the atmosphere at wavelength λ between s and s1.

[0052] It should be noted that the near-space atmospheric ultraviolet radiation simulation device provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the near-space atmospheric ultraviolet radiation simulation device and the near-space atmospheric ultraviolet radiation simulation method embodiments are based on the same concept, and their specific implementation process can be found in the method embodiments, which will not be repeated here.

[0053] Embodiments of this application also provide a computer device, please refer to... Figure 3The computer device includes a processor and a memory, the memory storing at least one instruction, at least one program, code set or instruction set, the at least one instruction, at least one program, code set or instruction set being loaded and executed by the processor to implement the near-space atmospheric ultraviolet radiation simulation method provided in the above-described method embodiments.

[0054] The embodiments of this application also provide a computer-readable storage medium storing at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, at least one program, code set, or instruction set is loaded and executed by a processor to implement the near-space atmospheric ultraviolet radiation simulation method provided in the above-described method embodiments.

[0055] Embodiments of this application also provide a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium and executes the computer program, causing the computer device to perform any of the near-space atmospheric ultraviolet radiation simulation methods described in the above embodiments.

[0056] For ease of description, the above systems or devices are described separately as various modules or units based on their functions. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware components.

[0057] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0058] Finally, it should be noted that in this document, relational terms such as first, second, third, and fourth are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0059] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for simulating near-space atmospheric ultraviolet radiation, characterized in that, The method includes: Based on the initial solar ultraviolet radiation irradiance and the preset solar ultraviolet extinction section library, the transmission attenuation solution and photoionization process of the incident solar ultraviolet radiation are calculated, and the solar irradiance distribution and photoelectron generation rate source function of each altitude layer are obtained. Based on the photoelectron generation rate source function, the pre-set electron collision reaction cross section library, and the chemical reaction database, the energy spectrum solution and chemical equilibrium calculation of atmospheric electron transport and composition evolution processes are performed to obtain the electron energy flux spectrum and chemical composition number density distribution at different altitudes. Based on the electron energy flux spectrum and radiative transfer parameters, the coupling effect between ultraviolet luminescence processes with strong absorption spectral lines of different mechanisms is calculated and corrected to obtain the final emissivity of all spectral bands after coupled multiple scattering. Based on the emissivity of the luminescent body, standard spectral line shape data, and scattered radiation source terms, the spectral integral emission and the whole-path radiative transfer process are calculated by spectral expansion and integrated synthesis to obtain the total ultraviolet spectral radiance at the detector end.

2. The method as described in claim 1, characterized in that, The solar irradiance distribution and photoelectron generation rate source function for each altitude level are obtained as follows: Based on atmospheric gas number density and solar ultraviolet extinction cross section data at different altitudes, the component extinction contribution of the solar radiation transmission path is calculated by layer-by-layer accumulation to obtain the total atmospheric optical thickness of all extinction channels at different altitudes. Using the solar irradiance at the top of the atmosphere as the initial boundary, and based on the solar incident zenith angle and the total optical thickness of the atmosphere, the attenuation of the obliquely incident solar ultraviolet radiation is calculated to obtain the solar ultraviolet irradiance of all wavelength channels at different altitudes. Based on the solar ultraviolet radiation irradiance, ionization channel cross-section and photon energy parameters of each altitude layer, the photoionization yield process is quantitatively calculated channel by channel to obtain the photoelectron generation rate and electron energy corresponding to each ionization channel. At the same altitude level, the photoelectron generation rates of all ionization channels in the same energy range are summed to obtain the photoelectron generation rate source function used to characterize the electron energy resolution at different altitude levels.

3. The method as described in claim 1, characterized in that, The electron energy flux spectrum and chemical composition number density distribution of each altitude layer were obtained as follows: Based on the electron energy range and electron collision cross section data, the electron energy spectrum calculation system is discretized and initial parameters are matched to obtain a discrete energy spectrum parameter set. Based on the losses of electrons when they collide with electrons and atmospheric gases, the electron migration contribution between different energy spectral intervals is calculated and summarized to obtain the electron conversion rate matrix for each energy spectral interval. Based on the energy loss path during electron collisions, the net electron energy loss of each energy spectral interval is quantitatively calculated to obtain the total electron loss rate corresponding to each energy spectral interval. Based on the generation rate of photoelectrons, the electron conversion rate and the total loss rate of the current altitude layer, the local electron energy balance equation is solved to obtain the discrete electron energy flux spectrum of the current altitude layer. Based on the discrete electron energy flux spectrum and atmospheric gas number density at the current altitude, the atmospheric component ionization process caused by electron collisions is calculated to obtain the ion generation rate caused by electron collisions at the current altitude. The continuity equations for each ion and excited-state chemical composition are solved in steady state based on the ion generation rate of the current layer to obtain the number density of ions and excited-state chemical composition of atmospheric gases at the current altitude. Using the incident electron energy spectrum at the top of the atmosphere as the initial boundary, the electron energy spectrum distribution and chemical composition number density are calculated iteratively from top to bottom to obtain the electron energy flux spectrum and chemical composition number density distribution of the entire altitude layer.

4. The method as described in claim 1, characterized in that, The final emissivity of the spectral bands was obtained as follows: Based on the solar ultraviolet radiation irradiance, total density of luminescent components and fluorescence luminescence parameters at different altitudes, the local luminescence intensity of solar fluorescence excitation bands is quantitatively calculated to obtain the preliminary bulk emissivity of solar fluorescence. Based on the electron energy flux spectrum, total density of luminescent components, and electron excitation cross-section parameters at different altitudes, the local luminescence intensity of the electron collision instantaneous excitation band is integrally calculated to obtain the initial bulk emissivity of electron collision instantaneous luminescence. Based on the chemical component fraction density, chemical reaction rate coefficient and spontaneous emission coefficient at different altitudes, the equilibrium process of metastable components is calculated to obtain the initial bulk emissivity of metastable spontaneous emission. Based on three initial bulk emissivity, atmospheric absorption parameters, and initial values ​​of multiple scattering radiance, the luminescence source function of the strong self-absorption band is iteratively coupled and corrected to obtain the corrected final bulk emissivity.

5. The method as described in claim 1, characterized in that, The total ultraviolet spectral radiance is calculated as follows: The wavelength distribution pattern of each spectral band is matched and extracted according to the preset standard absorption spectrum library to obtain the normalized spectral line shape coefficient corresponding to each spectral band. Based on the final bulk emissivity of the spectral band and the normalized spectral line shape coefficient, the integral form of the luminescent source term is expanded and superimposed with the wavelength dimension to obtain the wavelength-resolved bulk emissivity of different height layers. Based on the spectral emissivity of different altitude layers, the preset atmospheric scattering radiation source function and detection path, and atmospheric extinction parameters, an integrated equation is constructed and the full-path integral is solved for the coupled radiation process of non-equilibrium emission and atmospheric scattering, so as to obtain the total ultraviolet spectral radiance at the detector receiver.

6. The method as described in claim 5, characterized in that, The total ultraviolet spectral radiance is calculated using the following formula: Among them, L λ λ represents the spectral radiance at wavelength λ sensed by the detector; s0 is the starting position of radiative transfer, and s1 is the ending position of the detector; J λ J is the spectral bulk emissivity at point s along the transmission path. λm Let τ be the spectral scattering radiation source function at point s along the transmission path; λ (s,s1) represents the optical thickness of the atmosphere at wavelength λ between s and s1.

7. A near-space atmospheric ultraviolet radiation simulation device, characterized in that, The device includes: The first calculation module is used to perform transmission attenuation calculation and photoionization process deduction of incident solar ultraviolet radiation based on the initial solar ultraviolet radiation irradiance and the preset solar ultraviolet extinction section library, and obtain the solar irradiance distribution and photoelectron generation rate source function for each altitude layer. The second calculation module is used to perform energy spectrum calculation and chemical equilibrium calculation on atmospheric electron transport and composition evolution processes based on the photoelectron generation rate source function, the preset electron collision reaction cross section library and chemical reaction database, so as to obtain the electron energy flux spectrum and chemical composition number density distribution at different altitudes. The third calculation module is used to calculate and correct the coupling effect between ultraviolet luminescence processes with strong absorption spectral lines of different mechanisms based on the electron energy flux spectrum and radiative transfer parameters, so as to obtain the final emissivity of all spectral bands after coupling multiple scattering. The fourth calculation module is used to perform spectral expansion and integrated calculation of the spectral integral emission and the whole-path radiative transfer process based on the emissivity of the luminescent body, standard spectral line shape data and scattered radiation source terms, so as to obtain the total ultraviolet spectral radiance at the detector end.

8. A computer device, characterized in that, The computer device includes a memory and a processor. The memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory to implement the steps of the method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the steps of the method described in any one of claims 1-6.

10. A computer program product, characterized in that, Includes a computer program, which, when executed by a processor, implements the steps of the method according to any one of claims 1-6.

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