Multi-cloud system radiation transfer modeling method and device
By using a multi-cloud system radiative transfer modeling method, cloud physical and observational geometric parameters are obtained. Combined with atmospheric background state data, the cloud system radiative process is decomposed, solving the problem of inaccurate inversion of multi-cloud radiative characteristics under the single-cloud assumption. This enables accurate simulation of multi-cloud radiative characteristics and accurate provision of cloud radiative products.
Patent Information
- Application Number
- CN202511533475.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-24
- Publication Date
- 2026-01-30
AI Technical Summary
Existing methods for obtaining cloud radiation characteristics based on the single-layer cloud assumption cannot accurately invert the radiation characteristics of multi-layer clouds, resulting in inaccurate estimation of cloud radiation effects and affecting meteorological and climate model predictions.
A multi-cloud system radiative transfer modeling method is adopted. By acquiring cloud physical parameters and observation geometric parameters, combined with atmospheric background state data, the radiance of each pixel is calculated. Different types of transmission and reflection processes in the cloud system are decomposed, and a doubling-accumulation scheme is used for radiative calculation.
It achieves accurate simulation of the radiation characteristics of multi-layer clouds, improves the accurate estimation of cloud radiation effects, serves the radiation budget of the land-atmosphere system and weather and climate model prediction, and provides more accurate cloud radiation products.
Smart Images
Figure CN121435488A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of satellite remote sensing, and in particular to a multi-cloud layer system radiation transmission modeling method and device. BACKGROUND
[0002] Multi-layer cloud has an important influence on cloud characteristic inversion and atmospheric radiation balance and climate change, and its optical characteristics are one of the problems to be solved in satellite remote sensing of cloud characteristics at present. The acquisition of full-spectrum cloud field radiation characteristics is realized based on the single-layer cloud assumption at present, however, the stacked multi-layer cloud shape such as ice cloud and water cloud is a normal feature of the actual global cloud field distribution, which inevitably makes the cloud radiation characteristics obtained based on the single-layer cloud assumption have great deviation. Researches have confirmed that the existence of multi-layer cloud will significantly affect the accurate estimation of cloud radiation effect. The different radiation effects of high and low cloud layers and the complex radiation interaction between them bring great uncertainty to the research of multi-layer cloud radiation effect. More accurately characterizing the radiation characteristics of multi-layer cloud can better serve the radiation balance of the earth-atmosphere system and the prediction of weather and climate models. Therefore, it is of great significance to propose a radiation characteristic modeling method for multi-layer cloud for satellite quantitative inversion of cloud type and characteristics, and can provide more accurate cloud radiation products for meteorological monitoring and climate observation. SUMMARY
[0003] The embodiment of the present application provides a multi-cloud layer system radiation transmission modeling method and device, electronic equipment and storage medium, which can simulate the radiation characteristics of multi-layer cloud.
[0004] In a first aspect, the embodiment of the present application provides a multi-cloud layer system radiation transmission modeling method, characterized in that it comprises: Obtaining cloud physical parameters and observation geometric parameters; wherein the cloud physical parameters include cloud phase state, cloud top height, cloud bottom height, cloud optical thickness and cloud effective particle radius, and the observation geometric parameters include observation time, solar zenith angle, solar azimuth angle, observation zenith angle and observation azimuth angle; Determining the cloud bidirectional reflectance / transmittance corresponding to each pixel in combination with the cloud physical parameters and the observation geometric parameters; Obtaining atmospheric background state data, and determining the solar radiation brightness of the cloud top layer according to the observation geometric parameters; wherein the atmospheric background state data includes solar radiation data at different angles, atmospheric transmittance at different angles and temperature of the underlying surface with different properties; Determining the uplink radiation data of the underlying surface with different properties according to the atmospheric background state data; Determining the radiation brightness of each pixel according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the uplink radiation data of the underlying surface with different properties and the reflectivity of the underlying surface.
[0005] In a second aspect, the embodiments of the present application further provide a multi-cloud system radiation transmission modeling device for implementing the method described in any of the embodiments of the present application, and the device comprises: An acquisition module is configured to acquire cloud physical parameters and observation geometry parameters, wherein the cloud physical parameters comprise cloud phase state, cloud top height, cloud bottom height, cloud optical thickness and cloud effective particle radius, and the observation geometry parameters comprise observation time, solar zenith angle, solar azimuth angle, observation zenith angle and observation azimuth angle. A cloud bidirectional reflectance / transmittance module is configured to determine cloud bidirectional reflectance / transmittance corresponding to each pixel in combination with the cloud physical parameters and the observation geometry parameters. An atmospheric data module is configured to acquire atmospheric background state data and determine cloud top layer solar radiation brightness according to the observation geometry parameters, wherein the atmospheric background state data comprises solar radiation data at different angles, atmospheric transmittance at different angles and temperature of underlying surface with different properties. A radiation acquisition module is configured to determine upwelling radiation data of the underlying surface with different properties according to the atmospheric background state data. A radiation calculation module is configured to determine radiation brightness of each pixel according to cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, upwelling radiation data of the underlying surface with different properties and underlying surface reflectance.
[0006] In a third aspect, the embodiments of the present application further provide an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the method described in any of the embodiments of the present application when executing the computer program.
[0007] In a fourth aspect, the embodiments of the present application further provide a computer readable storage medium having a computer program stored thereon, and the computer program causes a computer to execute the method described in any of the embodiments of the present application when the computer program is executed in the computer.
[0008] Compared with the prior art, the present application has at least the following beneficial effects: The present application uses fixed wavelength satellite remote sensing data to realize the inversion of cloud optical radiation characteristics in the spectral range of 2-14 μm. Moreover, the theoretical model uses a multi-layer cloud distribution assumption which is more consistent with the actual situation, reconstructs the cloud radiation transmission process, and eliminates the theoretical deviation of the simplified model based on single-layer cloud distribution in the actual scene. The radiation decoupling technology of the present application ensures that the cloud remote sensing scene radiation image of a specified spectral range and a specified field of view can be calculated at a minute level. The present application can be used as a basis for developing remote sensing scene simulation software and solves the modeling problem of the key part. BRIEF DESCRIPTION OF DRAWINGS
[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required by the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.
[0010] Figure 1 is a schematic diagram of single-layer cloud and double-layer cloud; Figure 2 is a schematic diagram of the decomposition process of solar radiation and thermal radiation transmission of multi-layer cloud; Figure 3 is a schematic diagram of the decomposition process of solar radiation and thermal radiation transmission of single-layer cloud; Figure 4 is a simulated radiance image (first row) and an observed radiance image (second row) under four spectral channels 3.6-3.8, 4.3-4.4, 4.4-4.6 and 8.1-9 μm. DETAILED DESCRIPTION
[0011] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.
[0012] For modeling the radiation characteristics of multi-layer cloud, a special radiation transmission model needs to be constructed instead of using a radiation transmission model based on the single-layer cloud assumption to simply repeat the calculation for each pixel. The main reason is that most of the global cloud distribution is multi-layer cloud, among which the double-layer cloud system with upper ice cloud and lower water cloud structure is the most typical and common, and its proportion is more than 50%. The schematic diagram of single-layer cloud and double-layer cloud is shown in FIG. 1. Figure 1
[0013] Solar radiation will be reflected and scattered between multi-layer clouds. Water cloud has smaller transmittance in each spectral band. For single-layer water cloud, the radiation of the ground and atmosphere below the cloud can hardly penetrate the cloud to the upper part of the cloud. Compared with water cloud, the radiation spectral characteristics of ice cloud are more complex due to its different cloud particle structure. Therefore, for the multi-layer cloud with upper ice cloud and lower water cloud, its radiation transmission characteristics are completely different from those of single-layer ice cloud or single-layer water cloud. Using the concept of single-layer cloud to calculate the radiation brightness of the top of multi-layer cloud will have a large difference from the actual situation.
[0014] Based on this, the embodiments of the present application provide a multi-cloud layer system radiation transmission modeling method, which comprises: obtaining cloud physical parameters and observation geometry parameters; wherein the cloud physical parameters include cloud phase, cloud top height, cloud bottom height, cloud optical thickness and cloud effective particle radius, and the observation geometry parameters include observation time, solar zenith angle, solar azimuth angle, observation zenith angle and observation azimuth angle; determining cloud bidirectional reflectance / transmittance corresponding to each pixel in combination with the cloud physical parameters and the observation geometry parameters; obtaining atmospheric background state data, and determining cloud top layer solar radiation luminance according to the observation geometry parameters; wherein the atmospheric background state data includes solar radiation data at different angles, atmospheric transmittance at different angles and temperature of underlying surface with different properties; determining upwelling radiation data of the underlying surface with different properties according to the atmospheric background state data; determining radiation luminance of each pixel according to cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation luminance, the upwelling radiation data of the underlying surface with different properties and underlying surface reflectance.
[0015] In the embodiment, the type (single-layer cloud or multi-layer cloud) of the cloud corresponding to each pixel of the detector and the reflectance and transmittance thereof can be determined through the cloud physical data and the observation geometry parameters. The solar radiation luminance and the upwelling radiation data of the underlying surface can be determined according to the atmospheric background state data. The obtained data can be calculated to obtain the radiation luminance obtained by each pixel. The cloud physical parameters, the observation geometry parameters and the atmospheric background state data obtained in the application can be simulated by a software product, or can be real data detected by a detection device. Through the method provided in the application, the remote sensing radiance image at the entrance pupil of the sensor can be calculated, that is, the cloud radiation characteristics under the complex state of the multi-layer cloud can be accurately simulated.
[0016] In the embodiment, when constructing the required input parameter data, the observation data of the spectral imagers MODIS and VIIRS on the polar orbit satellites Aqua and Suomi-NPP can be used to provide cloud physical parameter inversion products, including cloud phase, cloud top height, cloud bottom height, cloud optical thickness, cloud effective particle radius, and the observation geometry corresponding to the products, including observation time, solar zenith angle, solar azimuth angle, observation zenith angle and observation azimuth angle. These data can be resampled to 1 km*1 km resolution. The atmospheric background state data can be provided by the atmospheric reanalysis product, and the solar direct radiation reaching the cloud top under the real atmospheric conditions and the observation geometry conditions can be calculated by using MODTRAN and the model calculation under the conditions of the atmospheric state and the observation geometry and the scattering radiation ; and the self-radiation of each part in the multi-layer cloud system can be calculated by using the atmospheric background state data.
[0017] In one embodiment of the present application, the determination of the radiation brightness of each pixel according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the upwelling radiation data of the underlying surface of different properties and the underlying surface reflectivity comprises: Decoupling the atmosphere and the inhomogeneous boundary, decomposing different types of processes of transmission and reflection in the earth-atmosphere system according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the upwelling radiation data of the underlying surface of different properties and the underlying surface reflectivity, and calculating the irradiance of the cloud system by using the doubling-adding scheme.
[0018] After the gas absorption, cloud particle scattering and the perfect construction of the ground surface model, combined with the geometric angle relationship between the satellite observation and the sun, the decoupling of the atmosphere and the inhomogeneous boundary based on the modeling of the continuous order radiation interaction principle, and the decomposition of different types of processes of transmission and reflection of radiation in the earth-atmosphere system, the doubling-adding scheme is used to realize the construction of the fast atmospheric radiation transfer model under the condition of cloud, which can simulate the apparent irradiance of the multi-layer cloud in the full spectrum from visible light to thermal infrared. In the following, the contribution of each specific process decomposed from the multi-layer cloud distribution to the total apparent radiance will be derived, and the calculation method and the overall calculation process will be illustrated.
[0019] Please refer to Figure 2 In one embodiment of the present application, the cloud corresponding to each pixel includes the following three cases: The cloud corresponding to the pixel is water cloud, the cloud corresponding to the pixel is ice cloud, and the cloud corresponding to the pixel is water-ice multi-layer cloud; When the cloud corresponding to the pixel is ice-water multi-layer cloud, the different types of processes of transmission and reflection in the earth-atmosphere system are decomposed according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the upwelling radiation data of the underlying surface of different properties and the underlying surface reflectivity, comprising: The radiation brightness contributed by the process 1 that the solar radiation passes through the cloud layer to reach the underlying surface and is reflected to the field of view of the detector is: Wherein, is the solar incident zenith angle, is the solar incident azimuth angle, is the observation zenith angle, is the observation line of sight azimuth angle; is the ice cloud transmittance, is the water cloud transmittance; is the underlying surface reflectivity, is the cloud top atmospheric transmittance, represents the solar radiation brightness reaching the cloud top; In this embodiment, the radiation is transmitted in the atmosphere, and is subjected to absorption and scattering of atmospheric molecules and aerosol, cloud and other particles, and thus is attenuated. The attenuation capability of the atmospheric medium on a transmission path is characterized by its optical thickness or transmittance, and the relationship between the two parameters can be expressed as: where T represents the transmittance, h represents the optical thickness, represents the wave number of a monochromatic electromagnetic wave (in infrared radiation, the wave number is usually used). The greater the optical thickness of the atmospheric medium on the transmission path, the smaller the transmittance.
[0020] For the gas absorption process, although the strict line-by-line integral method can accurately calculate the atmospheric gas transmittance, it cannot meet the needs of actual satellite spectral imager simulation due to its low calculation efficiency. Therefore, in this project, the correlation k distribution method is used, that is, a few points are used to calculate the atmospheric transmittance with high precision, so as to improve the calculation efficiency. At the same time, in the actual atmospheric processing process, the influence of the change of temperature and pressure on the absorption on the path is fully considered. In this project, based on the wave number resolution of 0.01 cm-1 and the high-resolution HITRAN database, the absorption coefficient or optical thickness of each atmospheric gas is calculated according to the line-by-line integral method, and an independent correlation k distribution (CKD) model is established for each spectral channel. On the basis of considering the calculation accuracy and efficiency, 8 integral points are selected in the g space for each channel CKD model, and the corresponding atmospheric gas absorption coefficient is calculated to establish a correlation calculation table, and the absorption of each layer of the actual atmosphere or the atmospheric transmittance can be obtained by interpolation calculation.
[0021] It should be noted that the surface radiation characteristics represent the change of the underlying surface, and are very important in the process of radiation transmission. In order to simplify the calculation, it is assumed that the surface is a Lambertian surface and is only characterized by the surface albedo. In this project, based on the MODIS three-level surface product (MCD43), the land surface albedo data module of global range is optimized, and the difference of the albedo of water surface in different wave bands is fully considered, and a global monthly average surface albedo calculation table with a resolution of 0.05 degree x 0.05 degree is established.
[0022] The radiation brightness contributed by the process 2 in which the solar radiation passes through the ice cloud and is reflected to the field of view of the detector at the top surface of the water cloud is: wherein, is the reflectivity of the water cloud; The radiation brightness contributed by the process 3 in which the solar radiation is reflected to the field of view of the detector at the top surface of the ice cloud is: wherein, is the ice layer reflectivity; Processes 4, 5, 6 respectively represent the radiation brightness of the underlying surface, ice cloud, water cloud, and self-upward radiation reaching the detector field of view through absorption and scattering, and are respectively: wherein, is the self-temperature, respectively represent the underlying surface, water cloud, and ice cloud self-upward radiation, which can be given by the Planck function of blackbody radiation: .
[0023] Please refer to Figure 3 In an embodiment of the present application, the cloud corresponding to each pixel includes the following three cases: the cloud corresponding to the pixel is a water cloud, the cloud corresponding to the pixel is an ice cloud, and the cloud corresponding to the pixel is a water-ice multi-layer cloud; When the cloud corresponding to the pixel is a single-layer water cloud or a single-layer ice cloud, the different types of processes of transmission and reflection in the ground-atmosphere system are decomposed according to the bidirectional reflectance / transmittance of the cloud corresponding to each pixel, the solar radiation brightness, the upward radiation data of the underlying surface with different properties, and the underlying surface reflectivity, including: The radiation brightness of process 1, in which the solar radiation passes through the single-layer water cloud or the single-layer ice cloud to reach the underlying surface and is reflected to the detector field of view, is: wherein, is the solar incident zenith angle, is the solar incident azimuth angle, is the observation zenith angle, is the observation line-of-sight azimuth angle; is the water cloud or ice cloud transmittance, when the single-layer cloud is a water cloud, the value is the water cloud transmittance , when the single-layer cloud is an ice cloud, the value is the ice cloud transmittance ; is the underlying surface reflectivity, is the cloud-top upper atmosphere transmittance, represents the solar radiation brightness reaching the cloud top; The radiation brightness of process 2, in which the solar radiation is reflected to the detector field of view at the water cloud or ice cloud top, is: wherein, is the water cloud and ice cloud reflectivity, when the single-layer cloud is a water cloud, the value is the water cloud reflectivity , when the single-layer cloud is an ice cloud, the value is the ice cloud reflectivity ; Processes 3, 4, and 5 represent the absorption and scattering of the underlying surface, ice / water cloud, and their own upward radiation reaching the detector's field of view, respectively. Their contribution to radiance can be expressed by the following formula: in, For its own temperature, include When a pixel corresponds to a water cloud, this value is... When a pixel corresponds to a water cloud, this value is... , These represent the upward radiation from the underlying surface, water cloud, and ice cloud, respectively. This refers to the zenith radiance.
[0024] In one embodiment of the present invention, the solar radiation brightness of the cloud top layer includes direct solar radiation and diffuse solar radiation.
[0025] In one embodiment of the present invention, the direct solar radiation is calculated using the following formula: in, E represents direct solar radiation, and E represents solar radiation incident at the top of the atmosphere.
[0026] In one embodiment of the present invention, the solar scattered radiation is calculated using the following formula: in, E represents the solar scattered radiation, and E represents the solar radiation incident at the top of the atmosphere. Figure 4 The simulation results and MODIS observation results are shown in four band ranges.
[0027] This invention provides a multi-cloud system radiative transfer modeling device. The device can be implemented in software, hardware, or a combination of both. From a hardware perspective, a hardware architecture diagram of the electronic device housing the multi-cloud system radiative transfer modeling device provided in this invention includes, in addition to the processor, memory, network interface, and non-volatile memory, other hardware such as a forwarding chip responsible for processing packets. Taking software implementation as an example, as a logical device, it is formed by the CPU of the electronic device reading the corresponding computer program from the non-volatile memory into memory and running it. The multi-cloud system radiative transfer modeling device provided in this embodiment includes: The acquisition module is used to acquire cloud physical parameters and observation geometric parameters; wherein, the cloud physical parameters include cloud phase, cloud top height, cloud bottom height, cloud optical thickness and cloud effective particle radius, and the observation geometric parameters include observation time, solar zenith angle, solar azimuth angle, observation zenith angle and observation azimuth angle; The cloud bidirectional reflectivity / transmittance module is used to determine the cloud bidirectional reflectivity / transmittance corresponding to each pixel by combining the cloud physical parameters and the observation geometric parameters. An atmospheric data module is used to acquire atmospheric background state data and determine the solar radiation brightness of the cloud top layer based on the observed geometric parameters; wherein, the atmospheric background state data includes solar radiation data at different angles, atmospheric transmittance at different angles, and surface temperature of different properties; The radiation acquisition module is used to determine the uplink radiation data of the underlying surface with different properties based on atmospheric background state data; The radiation calculation module is used to determine the radiance of each pixel based on the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiance, the uplink radiation data of the underlying surface with different properties, and the reflectance of the underlying surface.
[0028] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on a multi-cloud system radiative transfer modeling apparatus. In other embodiments of the present invention, a multi-cloud system radiative transfer modeling apparatus may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.
[0029] The information interaction and execution process between the modules in the above-mentioned device are based on the same concept as the method embodiment of the present invention, and the specific details can be found in the description of the method embodiment of the present invention, and will not be repeated here.
[0030] This invention also provides an electronic device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a multi-cloud system radiative transfer modeling method according to any embodiment of this invention.
[0031] This invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform a multi-cloud system radiative transfer modeling method according to any embodiment of this invention.
[0032] Specifically, a system or apparatus equipped with a storage medium may be provided, on which software program code implementing the functions of any of the embodiments described above is stored, and the computer (or CPU or MPU) of the system or apparatus may read and execute the program code stored in the storage medium.
[0033] In this case, the program code read from the storage medium can itself implement the function of any of the above embodiments, and therefore the program code and the storage medium storing the program code constitute part of the present invention.
[0034] Storage media embodiments for providing program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, program code can be downloaded from a server computer via a communication network.
[0035] Furthermore, it should be clear that not only can the program code read by the computer be executed, but also the operating system or other components operating on the computer can be instructed based on the program code to perform some or all of the actual operations, thereby realizing the function of any of the embodiments described above.
[0036] Furthermore, it is understood that the program code read from the storage medium is written to the memory set in the expansion board inserted into the computer or to the memory set in the expansion module connected to the computer. Then, based on the instructions of the program code, the CPU or other components installed on the expansion board or expansion module execute some and all of the actual operations, thereby realizing the function of any of the above embodiments.
[0037] It should be noted that, in this document, relational terms such as "first" and "second" 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.
[0038] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.
[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method of multi-layer system radiative transfer modeling, the method comprising: The method comprises the following steps: Obtaining cloud physical parameters and observation geometry parameters; wherein the cloud physical parameters include cloud phase state, cloud top height, cloud bottom height, cloud optical thickness and cloud effective particle radius, and the observation geometry parameters include observation time, solar zenith angle, solar azimuth angle, observation zenith angle and observation azimuth angle; Combining the cloud physical parameters and the observation geometry parameters to determine the cloud bidirectional reflectance / transmittance corresponding to each pixel; Obtaining atmospheric background state data, and determining cloud top layer solar radiation brightness according to the observation geometry parameters; wherein the atmospheric background state data includes solar radiation data at different angles, atmospheric transmittance at different angles and temperature of underlying surface with different properties; Determining upwelling radiation data of the underlying surface with different properties according to the atmospheric background state data; Determining the radiation brightness of each pixel according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the upwelling radiation data of the underlying surface with different properties and the underlying surface reflectance.
2. The method of claim 1, wherein, The step of determining the radiation brightness of each pixel according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the upwelling radiation data of the underlying surface with different properties and the underlying surface reflectance comprises the following steps: Decoupling the atmosphere and the inhomogeneous boundary, decomposing different types of processes of transmission and reflection in the land-atmosphere system according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the upwelling radiation data of the underlying surface with different properties and the underlying surface reflectance, and calculating the irradiance of the cloud system by using the doubling-accumulation scheme.
3. The method of claim 2, wherein, The cloud corresponding to each pixel includes the following three cases: The cloud corresponding to each pixel is water cloud, the cloud corresponding to each pixel is ice cloud, and the cloud corresponding to each pixel is water-ice multi-layer cloud; When the cloud corresponding to each pixel is ice-water multi-layer cloud, decomposing different types of processes of transmission and reflection in the land-atmosphere system according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the upwelling radiation data of the underlying surface with different properties and the underlying surface reflectance, comprises the following steps: The radiation brightness contributed by process 1 that the solar radiation passes through the cloud layer to reach the underlying surface and is reflected to the field of view of the detector is: wherein is the solar zenith angle of incidence, is the solar azimuth angle of incidence, is the observer zenith angle, is the observer azimuth angle of view; is the ice cloud transmittance, is the water cloud transmittance; is the underlying surface reflectance, is the upper atmosphere transmittance above the cloud top, represents the solar radiance reaching the cloud top; The radiation brightness contributed by process 2 that the solar radiation passes through the ice cloud is reflected to the field of view of the detector at the top surface of the water cloud is: wherein, is the water cloud reflectivity; The radiation brightness contributed by process 3 that the solar radiation is reflected to the field of view of the detector at the top surface of the ice cloud is: wherein, is the ice layer reflectivity; Processes 4, 5, 6 respectively represent the radiation brightness contributed by the upwelling radiation of the underlying surface, the ice cloud, the water cloud and itself to the field of view of the detector after absorption and scattering, and are respectively: where, is the temperature of the surface, respectively represent the upward radiation of the underlying surface, water cloud, and ice cloud.
4. The method of claim 2, wherein, The cloud corresponding to each pixel includes the following three cases: The cloud corresponding to each pixel is water cloud, the cloud corresponding to each pixel is ice cloud, and the cloud corresponding to each pixel is water-ice multi-layer cloud; When the cloud corresponding to each pixel is single-layer water cloud or single-layer ice cloud, decomposing different types of processes of transmission and reflection in the land-atmosphere system according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the upwelling radiation data of the underlying surface with different properties and the underlying surface reflectance, comprises the following steps: The radiation brightness contributed by process 1 that the solar radiation passes through the single-layer water cloud or single-layer ice cloud to reach the underlying surface and is reflected to the field of view of the detector is: where is the solar zenith angle of incidence, is the solar azimuth angle of incidence, is the observer zenith angle, is the observer azimuth angle of line of sight; is the water cloud or ice cloud transmittance, which is the water cloud transmittance when the single layer cloud is a water cloud , which is the ice cloud transmittance when the single layer cloud is an ice cloud ; is the underlying surface reflectance, is the transmittance of the upper atmosphere above the cloud top, represents the solar radiance reaching the cloud top; The radiation brightness contributed by process 2 that the solar radiation is reflected to the field of view of the detector at the top surface of the water cloud or ice cloud is: wherein, is the water cloud reflectivity, and is the ice cloud reflectivity, and is the water cloud reflectivity, and Processes 3, 4 and 5 respectively represent the contributions of the underlying surface, the ice / water cloud and the self-upwelling radiation to the radiation brightness reaching the detector field of view after absorption and scattering, which can be represented by the following formula: where, is the temperature of the surface, includes when the pixel corresponds to water clouds, this value is when the pixel corresponds to water clouds, this value is , respectively represent the upwelling radiation of the underlying surface, water clouds, and ice clouds, is the zenith radiance.
5. The method of claim 1, wherein, The cloud top layer solar radiation brightness is the sum of the solar direct radiation and the solar scattered radiation.
6. The method of claim 5, wherein, The solar direct radiation is calculated by the following formula: wherein E is the solar radiation at the top of the atmosphere.
7. The method of claim 5, wherein, The solar scattered radiation is calculated by the following formula: wherein E is the solar radiation at the top of the atmosphere.
8. A multi-layer system radiative transfer modeling apparatus, characterized in that, The device for implementing the method of any one of claims 1-7 comprises: an acquisition module for acquiring cloud physical parameters and observation geometry parameters; wherein the cloud physical parameters include cloud phase state, cloud top height, cloud bottom height, cloud optical thickness and cloud effective particle radius, and the observation geometry parameters include observation time, solar zenith angle, solar azimuth angle, observation zenith angle and observation azimuth angle; a cloud bidirectional reflectance / transmittance module for determining the cloud bidirectional reflectance / transmittance corresponding to each pixel in combination with the cloud physical parameters and the observation geometry parameters; an atmospheric data module for acquiring atmospheric background state data and determining cloud top layer solar radiation brightness according to the observation geometry parameters; wherein the atmospheric background state data includes solar radiation data at different angles, atmospheric transmittance at different angles and temperature of underlying surface of different properties; a radiation acquisition module for determining upwelling radiation data of underlying surface of different properties according to the atmospheric background state data; a radiation calculation module for determining the radiation brightness of each pixel according to the cloud bidirectional reflectance / transmittance corresponding to each pixel, the solar radiation brightness, the upwelling radiation data of underlying surface of different properties and the underlying surface reflectance.
9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the method of any one of claims 1-7 when executing the computer program.
10. A computer readable storage medium having a computer program stored thereon, wherein the computer program, when executed in a computer, causes the computer to perform the method of any one of claims 1-7.