Method for simulating global UMLT area wind field and temperature and 0-30 km wind field
By combining WACCM atmospheric mode and ERA5 reanalysis data, the number of echo photons of the iron atom resonance fluorescence effect is calculated using the satellite-based lidar system, and one-sided problems of satellite-based lidar in the UMLT region wind field and temperature simulation are solved, achieving a more accurate and comprehensive simulation effect.
Patent Information
- Application Number
- CN202510829587.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-20
- Publication Date
- 2025-07-18
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
When the existing technology simulates satellite-based lidar to detect atmospheric wind fields and temperatures in the UMLT area, the simulation results are one-sided and lack comprehensive reference value, which cannot meet the needs of lidar load design.
The WACCM atmospheric mode and ERA5 reanalysis data were used, combined with the satellite-borne lidar system, the number of echo photons generated by the resonance fluorescence effect of iron atoms was calculated, the global atmospheric temperature and wind speed of the UMLT region were calculated through the response function, and the global atmospheric parameters were applied to calculate the error and display seasonal and regional characteristics.
It provides a more accurate simulation method, obtains more comprehensive UMLT regional wind field and temperature simulation results, and improves the accuracy and comprehensiveness of satellite-based lidar simulation.
Smart Images
Figure CN120334888A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of atmospheric remote sensing, and particularly to a method for simulating the global UMLT regional wind field, temperature, and 0 - 30 km wind field. Background Art
[0002] In the region approximately 75 - 115 km from the top of the mesosphere to the bottom of the thermosphere of the Earth's atmosphere (UMLT, Upper mesosphere and lower thermosphere), it is called the atmospheric metal layer. This is because meteor ablation generates metal elements such as Na, K, Ca, Fe, Mg, and K. The thermodynamic structure and dynamic characteristics of the atmosphere in this region are relatively complex, playing a very crucial role in processes such as the energy and momentum circulation of the atmosphere. There are many special natural phenomena here, such as high - altitude noctilucent clouds, mesopause inversion, and polar stratospheric clouds. In addition, gravity wave breaking makes the atmospheric disturbances in the top region of the mesosphere more intense, resulting in wind shear phenomena. Moreover, the atmospheric photochemical reactions in this region make the atmospheric composition have obvious diurnal variation characteristics. Among them, atmospheric temperature and wind are important components of atmospheric environmental elements. Detecting the atmospheric environment in the UMLT region helps to promote the development of aerospace activities and deepen the understanding of global climate change, having important scientific research and application significance.
[0003] Simulation is a key step in the development and application of lidar. Through simulation, it plays a guiding role in the design of lidar parameters. In the past process of simulating and detecting the atmospheric wind field and temperature in the UMLT region by spaceborne lidar, single - profile atmospheric parameters are often used, such as the US Standard Atmosphere Model. Especially for the simulation of ground - based lidar, in the simulation of resonance fluorescence lidar, the number density of metal atoms often uses the single - profile data measured at the site.
[0004] However, the simulation of the atmospheric wind field and temperature in the UMLT region by a single profile is one - sided. For spaceborne lidar, the simulation of the comprehensive detection performance of the atmospheric wind field and temperature is particularly important, and it has a more persuasive reference value for the design of lidar payloads. Summary of the Invention
[0005] Based on the above - mentioned technical problems, a method for simulating the global UMLT regional wind field, temperature, and 0 - 30 km wind field is provided. By simulating the detection performance of spaceborne iron lidar based on the WACCM atmospheric model and ERA5 re - analysis temperature and pressure data, the simulation results show obvious seasonal and regional characteristics, providing a more accurate method for spaceborne lidar simulation and enabling more comprehensive simulation results to be obtained.
[0006] A method for simulating and emulating the global UMLT regional wind field, temperature, and 0 - 30 km wind field provided by this application includes: Build a spaceborne lidar system and use the spaceborne lidar system to emit 372 nm laser towards the Earth's atmosphere; Based on the iron atomic number density in the WACCM atmospheric model and the temperature and pressure data in the ERA5 reanalysis data, calculate the number of echo photons generated by the received iron atomic resonance fluorescence effect; Based on the number of echo photons, calculate the global atmospheric temperature, global atmospheric wind speed in the UMLT region, and global atmospheric wind speed in the 0 - 30 km range; among them, calculating the global atmospheric wind speed in the 0 - 30 km range based on the number of echo photons includes: Use the dual - edge frequency discrimination method to construct the response function of the system based on the number of echo photons, and calculate the Doppler frequency quantity based on the response function; Based on the sensitivity of the frequency discriminator and the Doppler frequency quantity, calculate the radial wind speed in the 0 - 30 km range; Calculate the wind speed error in the 0 - 30 km range according to the total signal - to - noise ratio of the system.
[0007] In one embodiment, calculating the number of echo photons generated by the received iron atomic resonance fluorescence effect based on the iron atomic number density in the WACCM atmospheric model and the temperature and pressure data in the ERA5 reanalysis data includes: Based on the temperature and pressure data in the ERA5 reanalysis data, calculate the backscattering coefficient of atmospheric molecules; Calculate the global atmospheric molecular transmittance according to the backscattering coefficient of atmospheric molecules; Based on the iron atomic number density in the WACCM atmospheric model and the global atmospheric molecular transmittance, calculate the number of received iron atomic resonance fluorescence echo photons.
[0008] In one embodiment, the formula for calculating the number of received iron atomic resonance fluorescence echo photons based on the global atmospheric transmittance is as follows:
[0009] Among them, is the emission frequency of the laser; is the emission power of the laser; is the integration time; h is Planck's constant; c is the speed of light; is the wavelength emitted by the laser; is the differential cross - section of iron resonance fluorescence backscattering; is the iron atomic number density in the WACCM atmospheric model; z is the distance from the detection target to the ground; is the orbital altitude of the satellite platform operation; is the vertical resolution; A is the area of the receiving telescope; is the overall system efficiency, including the quantum efficiency of the detector and the optical efficiency of the system; G is the geometric factor of the lidar system; is the transmittance of the iron layer to the optical signal; is the global atmospheric molecular transmittance; is the noise.
[0010] In one embodiment, the calculation formula for the differential cross section of iron resonance fluorescence backscattering is as follows:
[0011]
[0012]
[0013] where, is the global atmospheric wind speed; e is the electric charge, is the oscillator strength; is the vacuum permittivity; is the electron mass; c is the speed of light; f Fe is the central frequency of the iron resonance absorption line; f is the observed fluorescence photon frequency; k B is the Boltzmann constant; T is the global atmospheric temperature; M Fe is the iron atom mass; is the Doppler broadening; σ L is the line width of the outgoing laser; A n is the relative abundance of stable isotopes; is the wavelength emitted by the laser; is the effective scattering cross section considering the Fe atom and the laser line width.
[0014] In one embodiment, calculating the global atmospheric temperature and global atmospheric wind speed in the UMLT region based on the number of echo photons includes: Defining a temperature response function based on the number of echo photons R T and a wind speed response function R V ; Calculating the global atmospheric temperature according to the temperature response function and calculating the global atmospheric wind speed according to the wind speed response function.
[0015] In one embodiment, the 372 nm laser has three different frequencies, which are respectively defined as f 0, f + andf - , where:
[0016] Calculate the global atmospheric temperature according to the temperature response function, and the formula is as follows:
[0017]
[0018]
[0019] Where is the emission frequency of the laser; is the temperature response function; , and are respectively f 0, f + and f - the echo photon numbers corresponding to three different frequency lasers; δf is the frequency adjustment amount; T is the global atmospheric temperature; is the Doppler broadening; σ L is the line width of the emitted laser; M Fe is the mass of the iron atom; is the wavelength emitted by the laser; is an intermediate parameter.
[0020] In one embodiment, calculating the global temperature according to the temperature response function further includes calculating the random error of the global atmospheric temperature, and the formula is as follows:
[0021]
[0022] Where Δ T night is the random error of the atmospheric temperature detected by the night spaceborne iron lidar in the UMLT region, and Δ T day is the random error of the atmospheric temperature detected by the day spaceborne iron lidar in the UMLT region; is , is the effective scattering cross section considering the Fe atom and the laser line width; ψ is the proportion time, SNR 0 is the signal ratio of the lidar.
[0023] In one embodiment, the 372 nm laser has three different frequencies, which are respectively defined as f 0, f + and f - , where:
[0024] The global atmospheric wind speed is calculated according to the wind speed response function, and the formula is as follows:
[0025]
[0026] where is the wind speed response function; , and are respectively f 0, f + and f - the echo photon numbers corresponding to the three different frequency lasers; is the global atmospheric wind speed; δf is the frequency adjustment amount; is the wavelength emitted by the laser.
[0027] In one embodiment, calculating the global atmospheric wind speed according to the wind speed response function further includes calculating the random error of the global atmospheric wind speed, and the formula is as follows:
[0028]
[0029] where ΔV R-night is the random error of the wind speed detected by the spaceborne iron lidar in the UMLT region at night, and ΔV R-day is the random error of the wind speed detected by the spaceborne iron lidar in the UMLT region during the day; is , is the effective scattering cross section considering Fe atoms and the laser linewidth; is the wavelength emitted by the laser; is the Doppler broadening; σ L is the linewidth of the emitted laser; ψ is the occupancy time; SNR 0 is the signal ratio of the lidar.
[0030] The present application adopts the above method for simulating and emulating the wind field, temperature and 0 - 30 km wind field in the global UMLT region, and has the following beneficial effects: The method proposed in the present invention for simulating the global atmospheric wind speed and temperature and calculating the corresponding errors by using the WACCM atmospheric model and ERA5 reanalysis data applies global-scale atmospheric parameters and shows obvious seasonal and regional characteristics, providing a more accurate method for spaceborne lidar simulation and enabling more comprehensive simulation results to be obtained. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 It is a flowchart of a method for simulating the global UMLT regional wind field, temperature, and 0 - 30 km wind field in one embodiment; Figure 2 It is a seasonal distribution diagram of the global iron atom number density at 90 km obtained from the WACCM-Fe atmospheric model in one embodiment; where (a) is spring; (b) is summer; (c) is autumn; (d) is winter; Figure 3 It is a schematic diagram of the seasonal distribution of the global wind speed error of the spaceborne iron lidar at 90 km in one embodiment; where (a) is spring; (b) is summer; (c) is autumn; (d) is winter; Figure 4 It is a schematic diagram of the seasonal distribution of the global temperature error of the spaceborne iron lidar at 90 km in one embodiment; where (a) is spring; (b) is summer; (c) is autumn; (d) is winter; Figure 5 It is a schematic diagram of the ERA5 reanalysis annual average temperature data (10 km) in one embodiment; Figure 6 It is a schematic diagram of the ERA5 reanalysis annual average pressure data (10 km) in one embodiment; Figure 7 It is a schematic diagram of the backscattering coefficient (10 km) at a wavelength of 372 nm in one embodiment; Figure 8 It is a schematic diagram of the transmittance (10 km) at a wavelength of 372 nm in one embodiment; Figure 9 It is a schematic diagram of the seasonal distribution of the global wind speed error of the spaceborne iron lidar (10 km) in one embodiment; where (a) is spring; (b) is summer; (c) is autumn; (d) is winter; Figure 10 It is a schematic diagram of a single-profile of the iron atom number density in one embodiment; Figure 11 It is a schematic diagram of a single-profile of the 372 nm atmospheric molecular backscattering coefficient in one embodiment; Figure 12Schematic diagram of the global seasonal distribution (10 km) of the 372 nm atmospheric molecule backscattering coefficient in an embodiment; wherein, (a) is spring; (b) is summer; (c) is autumn; (d) is winter; Figure 13 Schematic diagram of a single profile of the 372 nm atmospheric molecule transmittance in an embodiment; Figure 14 Schematic diagram of the global seasonal distribution (10 km) of the 372 nm atmospheric molecule transmittance in an embodiment; wherein, (a) is spring; (b) is summer; (c) is autumn; (d) is winter. Detailed implementation manners
[0032] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0033] A method for simulating and emulating the global UMLT regional wind field, temperature and 0 - 30 km wind field provided by the present application includes: S100, building a spaceborne lidar system and using the spaceborne lidar system to emit 372 nm laser towards the Earth's atmosphere.
[0034] S200, calculating the number of echo photons generated by the received iron atom resonance fluorescence effect based on the iron atom number density in the WACCM atmospheric model and the temperature and pressure data in the ERA5 reanalysis data.
[0035] The WACCM atmospheric model is a global atmospheric model, whose vertical range extends from the Earth's surface to about 140 km. This model has hybrid pressure vertical coordinates, with a total of 88 levels, and the horizontal resolution is 0.9°×1.25°. This model has a very detailed description of the middle and upper atmospheric processes, including non - local thermodynamic equilibrium, radiation transport, aurora processes, ion drag, and molecular diffusion and interactive chemistry modules of major and minor substances, so as to be able to solve most of the known neutral chemistry and major ion chemistry problems in the middle and upper atmosphere. The WACCM - Fe model performs excellently in simulating the iron layer, and can reproduce the strong positive correlation of temperature and iron density near the peak of the iron layer and the large negative correlation at about 100 km.
[0036] ERA5 is the fifth - generation global climate reanalysis data produced by the European Centre for Medium - Range Weather Forecasts (ECMWF), funded and supported by the Copernicus Climate Change Service (C3S). The reanalysis data has a horizontal resolution of 0.25°×0.25°, 37 pressure levels, from 1000 hPa to 1 hPa, and provides global data such as temperature, pressure, relative humidity, etc.
[0037] In one embodiment, step S200 includes: S210, calculating the backscattering coefficient of atmospheric molecules based on the temperature and pressure data in ERA5 reanalysis data.
[0038] Specifically, the number of atmospheric molecules per cubic meter at altitude Z is:
[0039] Then the atmospheric backscattering coefficient can be expressed as:
[0040] Where, is the wavelength emitted by the laser; is the backscattering cross section of atmospheric molecules; N m is the number density of atmospheric molecules; is the vertical resolution.
[0041] S220, calculating the global atmospheric molecular transmittance according to the backscattering coefficient of atmospheric molecules, the formula is as follows:
[0042] S230, calculating the number of received iron atom resonance fluorescence echo photons based on the iron atom number density and the global atmospheric molecular transmittance in the WACCM atmospheric model.
[0043] Specifically, the formula for calculating the number of received iron atom resonance fluorescence echo photons based on the global atmospheric transmittance is as follows:
[0044] Where, is the emission frequency of the laser; is the emission power of the laser; is the integration time; h is Planck's constant; c is the speed of light; is the wavelength emitted by the laser; is the differential cross section of iron resonance fluorescence backscattering; is the iron atom number density in the WACCM atmospheric model; z is the distance from the detection target to the ground; is the orbital altitude of the satellite platform operation; is the vertical resolution; A is the area of the receiving telescope; is the total system efficiency, including the quantum efficiency of the detector and the optical efficiency of the system; G is the geometric factor of the lidar system; is the transmittance of the iron layer to the optical signal; is the global atmospheric molecular transmittance; is the noise.
[0045] In one embodiment, the calculation formula for the differential cross-section of ferromagnetic resonance fluorescence backscattering is as follows:
[0046]
[0047]
[0048] wherein, is the global atmospheric wind speed; e is the electric charge amount, is the oscillator strength; is the vacuum permittivity; is the electron mass; c is the speed of light; f Fe is the central frequency of the ferromagnetic resonance absorption line; f is the observed fluorescence photon frequency; k B is the Boltzmann constant; T is the global atmospheric temperature; M Fe is the iron atom mass; is the Doppler broadening; σ L is the linewidth of the emitted laser; A n is the relative abundance of the stable isotope; is the wavelength emitted by the laser; is the effective scattering cross-section considering the Fe atom and the laser linewidth.
[0049] S300, calculate the global atmospheric temperature, the global atmospheric wind speed, and the global atmospheric wind speed at 0 - 30 km in the UMLT region based on the number of echo photons.
[0050] S310, define the temperature response function R T and the wind speed response function R V ; Specifically, the 372 nm laser has three different frequencies, which are respectively defined as f 0, f + and f - , where:
[0051] Define the temperature response function R T and the wind speed response function R V, the formula is as follows:
[0052]
[0053] Wherein, is the temperature response function; is the wind speed response function; 、 and are respectively f 0, f + and f - the number of echo photons corresponding to three different frequency lasers.
[0054] S320, calculate the global atmospheric temperature according to the temperature response function, and calculate the global atmospheric wind speed according to the wind speed response function.
[0055] In one embodiment, calculate the global atmospheric temperature according to the temperature response function, and the formula is as follows:
[0056]
[0057] Wherein, T is the global atmospheric temperature; δf is the frequency adjustment amount; is the Doppler broadening; σ L is the line width of the emitted laser; M Fe is the mass of iron atoms; is the wavelength emitted by the laser; is an intermediate parameter.
[0058] In one embodiment, calculate the global temperature according to the temperature response function T It also includes calculating the random error of the global atmospheric temperature, and the formula is as follows:
[0059]
[0060] Wherein, Δ T night is the random error of the atmospheric temperature in the UMLT region detected by the night spaceborne iron lidar; Δ T day is the random error of the atmospheric temperature in the UMLT region detected by the day spaceborne iron lidar; is , The effective scattering cross section considering Fe atoms and the laser linewidth; ψ is the occupancy time; SNR 0 is the signal ratio of the lidar.
[0061] In one embodiment, the global wind speed is calculated according to the wind speed response function, and the formula is as follows:
[0062] Where, is the global atmospheric wind speed; δf is the frequency adjustment amount; is the wavelength emitted by the laser.
[0063] In one embodiment, calculating the global atmospheric wind speed according to the wind speed response function further includes calculating the random error of the global atmospheric wind speed, and the formula is as follows:
[0064]
[0065] Where, Δ V R-night is the random error of the wind speed detected by the night spaceborne iron lidar in the UMLT region, Δ V R-day is the random error of the wind speed detected by the day spaceborne iron lidar in the UMLT region; is , is the effective scattering cross section considering Fe atoms and the laser linewidth; is the wavelength emitted by the laser; is the Doppler broadening; σ L is the linewidth of the emitted laser; ψ is the occupancy time; SNR 0 is the signal ratio of the lidar.
[0066] In one embodiment, calculating the 0-30 km atmospheric radial wind speed based on the echo photon number includes: constructing the response function of the system based on the echo photon number using the dual-edge frequency discrimination method, calculating the Doppler frequency quantity based on the response function; calculating the radial wind speed in the 0-30 km region based on the sensitivity of the frequency discriminator and the Doppler frequency quantity; calculating the wind speed error in the 0-30 km region according to the total signal-to-noise ratio of the system.
[0067] Specifically, constructing the response function of the system based on the backscattering signal using the dual-edge frequency discrimination method, and the formula is as follows:
[0068] Where, R is the response function of the system; N1 and N2 are the echo photon numbers finally detected by the two channels of the dual-edge frequency discrimination method respectively.
[0069] In one embodiment, based on the Rayleigh scattering signal, the Doppler principle is used to calculate the 0 - 30 km atmospheric radial wind speed according to the Doppler frequency quantity, including: Calculate the sensitivity of the frequency discriminator, and the formula is as follows:
[0070] Based on the sensitivity of the frequency discriminator and the Doppler frequency quantity, calculate the radial wind speed in the 0 - 30 km area, and the formula is as follows:
[0071] Among them, \(v\) is the frequency; is the response function corresponding to the frequency; \(c\) is the speed of light; and are the sensitivities of the two channels of the frequency discriminator respectively; is the response function value that generates the Doppler frequency shift; is the response function value without generating the Doppler frequency shift.
[0072] In one embodiment, calculate the wind speed error in the 0 - 30 km area according to the total signal - to - noise ratio of the system, and the formula is as follows:
[0073]
[0074] Among them, is the total signal - to - noise ratio of the system; is the wind speed error in the 0 - 30 km area; and are the signal - to - noise ratios of the two channels of the frequency discriminator respectively.
[0075] The method proposed by the present invention for simulating the global atmospheric wind speed and temperature by using the WACCM atmospheric model and ERA5 re - analysis data and calculating the corresponding errors applies global - scale atmospheric parameters and shows obvious seasonal and regional characteristics, provides a more accurate method for space - borne lidar simulation, and can obtain more comprehensive simulation results.
[0076] From Figure 2 and Figure 10 It can be seen that the iron atom distribution has obvious seasonal and regional distributions. In summer, the iron atom number density gradually increases from the North Pole to the South Pole, while in winter, the iron atom number shows the opposite trend. The maximum and minimum values of the iron atom number density appear in spring and winter respectively, with values of 6625.4 cm -3 and 2176.2 cm -3 , and the difference between the iron atom number densities is as high as 4449.2 cm -3。The number density distribution of iron atoms in spring and autumn is not as stratified as that in winter and summer, and the maximum value of the number density of iron atoms appears near the equator and in the Antarctic region.
[0077] Figure 3 Shows the global distribution of the wind speed detection error of the spaceborne iron lidar at an altitude of 90 km. It can be seen from the figure that the regional distributions of the wind measurement errors in summer and winter are exactly opposite. In summer, the error gradually increases from the southern hemisphere to the northern hemisphere, and the small values of the error are mainly distributed in the southern hemisphere. The minimum value of the wind measurement error appears in summer, with an error of 1.26 m / s, and the maximum value is 3.71 m / s, which appears in winter, with a difference of 2.45 m / s.
[0078] Figure 4 Shows the global temperature distribution detected by the spaceborne iron lidar at 90 km. It can be seen from the figure that the variation trend is the same as that of the wind speed. The maximum value of the temperature error is 3.71 K, and the minimum value is 2.13 K, which appear in winter and spring respectively, with a difference of 1.58 K.
[0079] From Figures 5 to 7 It can be seen that the above atmospheric model has an obvious regional distribution. The temperature is the highest near the equator and gradually decreases towards the poles. The temperature in the Antarctic is lower than that in the Arctic. The pressure gradually increases from the Antarctic to the Arctic, and reaches the maximum value in the Arctic region. The backscattering coefficient at a wavelength of 372 nm has a similar trend to the pressure, while the trend of the transmittance at 10 km is opposite to it, and the maximum value appears in the Antarctic.
[0080] Figure 8 Shows the global transmittance at 10 km. It can be seen that the maximum difference in transmittance is 0.15, and the gap is relatively obvious. Moreover, the global distribution has obvious regional differences, and the simulation effect is more reliable.
[0081] From Figure 9 It can be seen that the wind speed error at 10 km has obvious seasonal and regional characteristics. The minimum value of the wind speed error appears in spring, with an error of 1.3 m / s; the maximum value of the wind speed error appears in winter, with an error of 1.66 m / s; the wind speed errors in spring, autumn and winter are generally low in the high-latitude regions of the northern hemisphere, high in the 30°-60° of the southern hemisphere, and the larger values of the wind speed error in summer appear in the 30°-60° of the northern hemisphere.
[0082] From Figure 11 and Figure 12 It can be seen that the wind speed error at 10 km has obvious seasonal and regional characteristics. The minimum value of the wind speed error appears in spring, with an error of 1.3 m / s, and the maximum value of the wind speed error appears in winter, with an error of 1.66 m / s. The wind speed errors in spring, autumn and winter are generally low in the high-latitude regions of the northern hemisphere, high in the 30°-60° of the southern hemisphere, and the larger values of the wind speed error in summer appear in the 30°-60° of the northern hemisphere.
[0083] From Figure 13 and Figure 14 It can be seen that the global atmospheric transmittance at 10 km calculated from the temperature and pressure of ERA5 reanalysis data has obvious seasonality, with significantly higher transmittance at high altitudes in the Southern Hemisphere and showing regional characteristics at the same time.
[0084] Traditional simulation methods can only obtain the results of a single profile and cannot reflect the regional and seasonal nature of the simulation results, which deviate from the real results. This method is completely different from the effect obtained by the atmospheric parameters input in the traditional simulation system and can better reflect the authenticity and accuracy of the simulation results.
[0085] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.
[0086] The above-described embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.
Claims
1. A method for simulating and emulating the global UMLT regional wind field, temperature, and 0 - 30 km wind field, characterized in that, Including: Construct a spaceborne lidar system and use the spaceborne lidar system to emit 372 nm laser towards the Earth's atmosphere; Based on the iron atomic number density in the WACCM atmospheric model and the temperature and pressure data in the ERA5 reanalysis data, calculate the number of echo photons generated by the received iron atomic resonance fluorescence effect; Based on the number of echo photons, calculate the global atmospheric temperature, global atmospheric wind speed, and 0 - 30 km global atmospheric wind speed in the UMLT region; among them, calculating the 0 - 30 km global atmospheric wind speed based on the number of echo photons includes: Use the dual-edge frequency discrimination method to construct the response function of the system based on the number of echo photons, and calculate the Doppler frequency quantity based on the response function; Calculate the radial wind speed in the 0 - 30 km region based on the sensitivity of the frequency discriminator and the Doppler frequency quantity; Calculate the wind speed error in the 0 - 30 km region according to the total signal-to-noise ratio of the system.
2. The method according to claim 1, wherein Calculating the number of echo photons generated by the received iron atomic resonance fluorescence effect based on the iron atomic number density in the WACCM atmospheric model and the temperature and pressure data in the ERA5 reanalysis data includes: Calculate the backscattering coefficient of atmospheric molecules based on the temperature and pressure data in the ERA5 reanalysis data; Calculate the global atmospheric molecular transmittance according to the backscattering coefficient of atmospheric molecules; Calculate the number of echo photons of the received iron atomic resonance fluorescence based on the iron atomic number density in the WACCM atmospheric model and the global atmospheric molecular transmittance.
3. The method according to claim 2, wherein The formula for calculating the number of echo photons of the received iron atomic resonance fluorescence based on the global atmospheric transmittance is as follows: Among them, is the emission frequency of the laser; is the emission power of the laser; is the integration time; h is Planck's constant; c is the speed of light; is the wavelength emitted by the laser; is the differential cross section of the backward scattering of iron resonance fluorescence; is the number density of iron atoms in the WACCM atmospheric model; z is the distance from the detection target to the ground; is the orbital altitude of the satellite platform operation; is the vertical resolution; A is the area of the receiving telescope; is the total system efficiency, including the quantum efficiency of the detector and the optical efficiency of the system; G is the geometric factor of the lidar system; is the transmittance of the iron layer to the optical signal; is the global atmospheric molecular transmittance; is the noise.
4. The method according to claim 3, characterized in that, The formula for calculating the differential cross section of iron resonance fluorescence backscattering is as follows: Among them, is the global atmospheric wind speed; e is the electric charge, is the oscillator strength; is the vacuum permittivity; is the electron mass; c is the speed of light; f Fe is the central frequency of the iron resonance absorption line; f is the observed fluorescence photon frequency; k B is the Boltzmann constant; T is the global atmospheric temperature; M Fe is the iron atom mass; is the Doppler broadening; σ L is the linewidth of the emitted laser; A n is the relative abundance of stable isotopes; is the wavelength emitted by the laser; is the effective scattering cross section considering Fe atoms and the laser linewidth.
5. The method according to any one of claims 2 to 4, characterized in that, Calculating the global atmospheric temperature and global atmospheric wind speed in the UMLT region based on the number of echo photons includes: Define the temperature response function based on the number of echo photons R T and the wind speed response function R V ; Calculate the global atmospheric temperature according to the temperature response function and calculate the global atmospheric wind speed according to the wind speed response function.
6. The method according to claim 5, wherein The 372 nm laser has three different frequencies, which are defined as f 0, f + and f - , where: The formula for calculating the global atmospheric temperature according to the temperature response function is as follows: Among them, is the temperature response function; , and are respectively f 0, f + and f - the echo photon numbers corresponding to three different frequency lasers; δf is the frequency adjustment amount; T is the global atmospheric temperature; is the Doppler broadening; σ L is the line width of the emitted laser; M Fe is the iron atom mass; is the wavelength emitted by the laser; is an intermediate parameter.
7. The method according to claim 6, wherein Calculating the global temperature according to the temperature response function also includes calculating the random error of the global atmospheric temperature, and the formula is as follows: where, Δ T night is the random error of the atmospheric temperature detected by the spaceborne iron lidar in the UMLT region at night; Δ T day is the random error of the atmospheric temperature detected by the spaceborne iron lidar in the UMLT region during the day; is , is the effective scattering cross section considering Fe atoms and the laser linewidth; ψ is the proportion time; SNR 0 is the signal ratio of the lidar.
8. The method according to claim 5, characterized in that The 372 nm laser has three different frequencies, which are defined as f 0, f + and f - , where: The formula for calculating the global atmospheric wind speed according to the wind speed response function is as follows: Among them, is the wind speed response function; , and are respectively f 0, f + and f - the echo photon numbers corresponding to three different frequency lasers; is the global atmospheric wind speed; δf is the frequency adjustment amount; is the wavelength emitted by the laser.
9. The method according to claim 8, characterized in that, Calculating the global atmospheric wind speed according to the wind speed response function also includes calculating the random error of the global atmospheric wind speed, and the formula is as follows: where, Δ V R-night is the random error of the wind speed detected by the spaceborne iron lidar in the UMLT region at night, and Δ V R-day is the random error of the wind speed detected by the spaceborne iron lidar in the UMLT region during the day; is , is the effective scattering cross section considering Fe atoms and the laser linewidth; is the wavelength emitted by the laser; is the Doppler broadening; σ L is the linewidth of the emitted laser; ψ is the proportion time; SNR 0 is the signal ratio of the lidar.