Method for inversing cloud droplet spectrum information through combination of cloud radar and laser radar and related equipment

Abstract

The invention provides a method and related equipment for jointly inverting cloud droplet spectrum information through a cloud radar and a laser radar, and the method comprises the steps: for a current detection layer, combining a first backscattering coefficient of an inversion cloud droplet spectrum of the cloud radar with a second backscattering coefficient of an inversion cloud droplet spectrum of the laser radar determined by a first radar ratio, determining a backscattering coefficient ratio, determining a cloud droplet spectrum and a second radar ratio based on the backscattering coefficient ratio, obtaining cloud droplet spectrum information of an inversion result of a current detection layer when an absolute value of a difference value between the first radar ratio and the second radar ratio is smaller than a preset threshold value, performing inversion operation on a next detection layer to obtain the cloud droplet spectrum information, and performing layer-by-layer iteration to obtain the cloud droplet spectrum information. And finally obtaining cloud droplet spectrum information. The cloud droplet effective particle size and the cloud droplet spectrum distribution of the cloud are determined layer by layer through inversion operation, the cloud droplet spectrum effective particle size and the cloud droplet spectrum distribution which are vertically distributed are obtained, an aircraft carrying a cloud particle probe does not need to obtain cloud droplet spectrum information in the cloud, and the cost of obtaining the cloud droplet spectrum information is reduced.

Description

Technical Field

[0001] The present invention relates to the field of remote sensing technology, and particularly to a method and related device for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar. Background Art

[0002] The vertical distribution of cloud droplet spectrum is one of the most important and fundamental parameters in the description of cloud microcharacteristics, which is extremely important for carrying out research on cloud radiation effects, cloud dynamic processes, and weather and climate changes caused by clouds, and has important guiding significance in artificial weather modification operations. The vertical distribution of cloud droplet spectrum varies greatly in terms of cloud type, different stages of cloud occurrence and development, time and region at different altitudes, and has a large scale inhomogeneity.

[0003] Currently, the main way to obtain cloud droplet spectrum information is to carry a cloud particle probe on an aircraft, and the aircraft detects the droplet spectrum information of different parts in the cloud during cloud penetration flight. However, this observation method is expensive and costly. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a method and related device for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar. When using the solution provided by the present invention to obtain cloud droplet spectrum information, there is no need to use an aircraft to carry a cloud particle probe to fly and detect the droplet spectrum information of different parts of the cloud, thereby reducing the cost of obtaining cloud droplet spectrum information.

[0005] A method for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar includes:

[0006] Taking the first detection layer in the cloud as the target detection layer for retrieving the cloud droplet spectrum, and determining the detection height corresponding to the target detection layer. The cloud is divided into multiple detection layers from the cloud bottom to the cloud top according to a preset layer height, and the detection layer containing the cloud bottom in the cloud is the first detection layer in the cloud;

[0007] Determining the echo attenuation parameter corresponding to the target detection layer of the preset cloud radar;

[0008] Processing the echo attenuation parameter to obtain the first backscattering coefficient of the retrieved cloud droplet spectrum corresponding to the target detection layer;

[0009] Setting a first radar ratio;

[0010] Applying the first radar ratio to determine the second backscattering coefficient of the retrieved cloud droplet spectrum corresponding to the target detection layer of the lidar;

[0011] Determining a backscattering ratio based on the first backscattering coefficient and the second backscattering coefficient;

[0012] Determine the effective cloud droplet size and cloud droplet spectrum distribution corresponding to the backscattering ratio, and determine the second radar ratio corresponding to the effective cloud droplet size and cloud droplet spectrum distribution;

[0013] When the absolute value of the difference between the first radar ratio and the second radar ratio is not greater than a preset threshold, return to execute the step of setting the first radar ratio;

[0014] When the absolute value of the difference between the first radar ratio and the second radar ratio is greater than the preset threshold, determine the effective cloud droplet size and the cloud droplet spectrum distribution as the cloud droplet spectrum information of the target detection layer, and when the detection height has not reached the highest observation height of the lidar, determine the next detection layer of the cloud located in the target detection layer as the new target detection layer, and then return to execute the step of determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer.

[0015] An apparatus for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar, comprising:

[0016] A first determination unit, configured to use the first detection layer in the cloud as the target detection layer for retrieving the cloud droplet spectrum, and determine the detection height corresponding to the target detection layer, wherein the cloud is divided into multiple detection layers according to a preset layer height from the cloud bottom to the cloud top, and the detection layer including the cloud bottom in the cloud is the first detection layer in the cloud;

[0017] A second determination unit, configured to determine the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer;

[0018] A first acquisition unit, configured to process the echo attenuation parameter to obtain the first backscattering coefficient of the retrieved cloud droplet spectrum corresponding to the target detection layer;

[0019] A setting unit, configured to set a first radar ratio;

[0020] A third determination unit, configured to apply the first radar ratio to determine the second backscattering coefficient of the retrieved cloud droplet spectrum corresponding to the target detection layer by the lidar;

[0021] A fourth determination unit, configured to determine a backscattering ratio based on the first backscattering coefficient and the second backscattering coefficient;

[0022] A fifth determination unit, configured to determine the effective cloud droplet diameter and the cloud droplet spectrum distribution corresponding to the backscattering ratio, and determine a second radar ratio corresponding to the effective cloud droplet diameter and the cloud droplet spectrum distribution; when the absolute value of the difference between the first radar ratio and the second radar ratio is not greater than a preset threshold, return to execute the step of setting the first radar ratio; when the absolute value of the difference between the first radar ratio and the second radar ratio is greater than the preset threshold, determine the effective cloud droplet diameter and the cloud droplet spectrum distribution as the cloud droplet spectrum information of the target detection layer, and when the detection height does not reach the highest observation height of the lidar, determine the next detection layer of the cloud located in the target detection layer as the new target detection layer, and then return to execute the step of determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer.

[0023] A storage medium, the storage medium includes stored instructions, wherein, when the instructions are running, the device where the storage medium is located is controlled to execute the method for obtaining cloud droplet spectrum information as described above.

[0024] An electronic device, including a memory, and one or more instructions, wherein one or more instructions are stored in the memory and are configured to be executed by one or more processors to execute the method for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar as described above.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The present invention provides a method and related device for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar, including: for the current detection layer, combining the first backscattering coefficient of the cloud droplet spectrum retrieved by the cloud radar and the second backscattering coefficient of the cloud droplet spectrum retrieved by the lidar determined by applying the first radar ratio, determining the backscattering coefficient ratio, determining the cloud droplet spectrum and the second radar ratio based on the backscattering coefficient ratio, when the absolute value of the difference between the first radar ratio and the second radar ratio is less than the preset threshold, obtaining the cloud droplet spectrum information of the inversion result of the current detection layer, and then performing an inversion operation on the next detection layer to obtain the cloud droplet spectrum information, iterating layer by layer, and finally obtaining the cloud droplet spectrum information. By performing inversion operations layer by layer to determine the effective cloud droplet diameter and the cloud droplet spectrum distribution of the cloud, the vertically distributed effective cloud droplet diameter and the cloud droplet spectrum distribution are obtained, and there is no need for an aircraft equipped with a cloud particle probe to obtain cloud droplet spectrum information in the cloud, reducing the cost of obtaining cloud droplet spectrum information. Description of the Drawings

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on the provided drawings.

[0028] Figure 1 FIG. 4 is a flowchart of a method for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar provided in an embodiment of the present invention;

[0029] Figure 2 FIG. 8 is a flowchart of a method for determining the echo attenuation parameter corresponding to a preset cloud radar and a target detection layer provided in an embodiment of the present invention;

[0030] Figure 3 FIG. 12 is an example diagram of the relationship between the effective particle size and the backscattering ratio under different μ conditions provided in an embodiment of the present invention;

[0031] Figure 4 FIG. 16 is an example diagram of determining the effective particle size and the spectral shape parameter by using the correlation between the spectral shape parameter and the color ratio established by applying the Mie theory provided in an embodiment of the present invention;

[0032] Figure 5 FIG. 20 is a flowchart of the lidar for retrieving the backscattering coefficient of the cloud droplet spectrum provided in an embodiment of the present invention;

[0033] FIG. 6(a) is an example diagram of the echo signal of the lidar after distance correction;

[0034] FIG. 6(b) is an example diagram of the echo signal of the cloud radar;

[0035] FIG. 6(c) is an example diagram of the vertical distribution of the cloud radar reflectivity factor;

[0036] FIG. 7(a) is an example diagram of the standard vertical distribution and the inversion result of the effective particle size;

[0037] FIG. 7(b) is an example diagram of the standard vertical distribution and the inversion result of the number concentration;

[0038] Figures 8(a) to 8(d) FIG. 39 is an example diagram of adding 5% random error (30) to the echo intensity of the distance-corrected lidar and the inversion result;

[0039] Figures 9(a) to 9(d) FIG. 43 is an example diagram of adding 10% random error (30) to the echo intensity of the distance-corrected lidar and the inversion result;

[0040] Figures 10(a) to 10(d) FIG. 47 is an example diagram of adding 5% random error (30) to the echo signal of the cloud radar and the inversion result;

[0041] Figures 11(a) to 11(d) Example diagrams of adding 10% random errors (30 in number) to cloud radar echo signals and the inversion results;

[0042] Figure 12 Schematic structural diagram of a cloud radar and a lidar jointly inverting cloud droplet spectrum information provided by an embodiment of the present invention;

[0043] Figure 13 Schematic structural diagram of an electronic device provided by an embodiment of the present invention. Specific implementation manners

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] In this application, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including one..." does not exclude the presence of additional identical elements in the process, method, article or device including the said element.

[0046] Existing cloud inversion work focuses more on the macroscopic structure of clouds. Due to observational limitations and the lack of reasonable inversion methods, relatively little existing cloud droplet spectrum inversion work has been carried out. Currently, in the observation of cloud droplet spectra, it is mainly based on aircraft observations and radar and satellite remote sensing inversions. Aircraft observations are expensive, subject to many restrictions and limitations, it is difficult to obtain continuous observations of the vertical distribution of cloud droplet spectra in the vertical direction, there is a lack of understanding of the changes in cloud droplet spectra in the air, and there are difficulties in understanding microphysical processes and other problems. Satellite remote sensing can better obtain cloud droplet spectrum information at the cloud top. A single cloud radar can also obtain cloud droplet spectrum information by using an effective inversion algorithm based on power spectrum data, but the amount of power spectrum data is extremely large, and storage and subsequent analysis are relatively complex. In addition, the observational deviation, turbulence, and radar sensitivity of a single radar itself affect the power spectrum, resulting in an estimation deviation of the air vertical velocity, which in turn affects the inversion results of the cloud droplet spectrum. Moreover, current inversion algorithms are basically based on power spectrum data, with high requirements for the quality of initial power spectrum data, and there are many limiting conditions for cloud droplet spectrum inversion algorithms, and currently there is very little research.

[0047] To solve the problems existing in the prior art, the solution provided by the present invention uses a cloud radar and a lidar to jointly invert the effective diameter of cloud droplets and the cloud droplet size distribution, realizing the process of multi-stage radar remote sensing joint inversion of the cloud droplet size spectrum, solving the problems existing in using a single radar to invert the cloud droplet size spectrum, so as to obtain cloud droplet size spectrum information. The whole process does not require using an aircraft to carry a cloud particle probe for observation, reducing the cost of obtaining cloud droplet size spectrum information. Moreover, the effective diameter of cloud droplets and the vertical distribution of the cloud droplet size spectrum in the cloud droplet size spectrum information obtained by the present invention are convenient for scientific researchers to understand the changes of the cloud droplet size spectrum in the air and the internal dynamic characteristics and microphysical processes of clouds; by combining the cloud radar and the lidar, the influence of a single radar is reduced, and the accuracy and reliability of the inversion result of the cloud droplet size spectrum are improved.

[0048] The method for obtaining cloud droplet size spectrum information provided by the embodiments of the present invention can be applied to a ground-based remote sensing system, and the ground-based remote sensing system can be formed by using devices such as a radar and a computer. Refer to Figure 1 , which is a flowchart of a method for jointly inverting cloud droplet size spectrum information by a cloud radar and a lidar provided by the embodiments of the present invention, and is specifically described as follows.

[0049] S101. Take the first detection layer in the cloud as the target detection layer for inverting the cloud droplet size spectrum, and determine the detection height corresponding to the target detection layer. The cloud is divided into multiple detection layers from the cloud bottom to the cloud top according to a preset layer height, and the detection layer containing the cloud bottom in the cloud is the first detection layer in the cloud.

[0050] In the process of inverting the cloud droplet size spectrum of the present invention, it is necessary to iterate layer by layer from the bottom of the cloud to obtain the vertical distribution information of the effective diameter of cloud droplets and the cloud droplet size distribution of the cloud.

[0051] Preferably, the height of each detection layer can be the same, and can be the preset layer height. The preset layer height can be set according to actual observation requirements. For example, the preset layer height can be 100 meters.

[0052] S102. Determine the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer.

[0053] Refer to Figure 2 , which is a flowchart of a method for determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer provided by the embodiments of the present invention, and is specifically described as follows.

[0054] S201. Judge whether the target detection layer is the first detection layer in the cloud. If the target detection layer is the first detection layer in the cloud, execute S202; if the target detection layer is not the first detection layer in the cloud, execute S203.

[0055] S202. Determine that the echo attenuation parameter corresponding to the target detection layer is zero.

[0056] S203. Determine the first extinction coefficient of the previous detection layer in the cloud located at the target detection layer as the echo attenuation parameter of the target detection layer.

[0057] Preferably, the present invention uses a Ka-band cloud radar with a wavelength of 8.6 mm.

[0058] It should be noted that below the cloud base, it can be considered that the cloud radar signal has no attenuation and only scattering exists. Therefore, when the target detection layer is the first detection layer in the cloud, it is determined that the target detection layer has no echo attenuation parameter. At this time, the echo attenuation parameter corresponding to the cloud radar and the target detection layer can be determined to be zero.

[0059] When the target detection layer is not the first detection layer in the cloud, it is necessary to use the first extinction coefficient of the previous detection layer in the cloud located at the target detection layer as the echo attenuation parameter corresponding to the cloud radar and the target detection layer; further, the first extinction coefficient of the detection layer is obtained after being processed by the first backscattering coefficient of the detection layer and the second radar ratio corresponding to the detection layer. The acquisition process of the second radar ratio is referred to below.

[0060] Exemplarily, when the target detection layer is the second detection layer in the cloud, the echo attenuation parameter of the target detection layer is the first extinction coefficient of the first detection layer in the cloud.

[0061] The cloud radar echo has different attenuations in different detection layers. During the process of inverting the cloud droplet spectrum, substituting the attenuations of different detection layers for processing can obtain a more accurate inversion result.

[0062] S103. Process the echo attenuation parameter to obtain the first backscattering coefficient of the inverted cloud droplet spectrum corresponding to the target detection layer.

[0063] During the process of processing the echo attenuation parameter, such as: determining each first radar parameter of the cloud radar; performing operations on the echo attenuation parameter and each radar parameter to obtain the first backward scattering coefficient of the inverted droplet spectrum corresponding to the target detection layer.

[0064] It should be noted that each first radar parameter of the cloud radar can be determined based on the cloud radar equation. Each first radar parameter of the cloud radar includes but is not limited to cloud radar received power, cloud radar radar constant, radar transmitted power, detection height.

[0065] The cloud radar equation is expressed as:

[0066]

[0067] It should be noted that P c is the cloud radar received power, C c0 is the cloud radar radar constant, P c0 is the radar transmitted power, Z is the detection height, βc (Z) is the backscattering coefficient produced by cloud droplets, σ c (z') is the echo attenuation coefficient, which is the echo attenuation parameter mentioned above. Further, σ c (z') can be understood as the first extinction coefficient of the previous detection layer located at the target detection layer. Further, Z at this time can also be understood as the detection height. For example, the detection height can be the height from the ground to the target detection layer, and the target detection layer is included in the detection height.

[0068] Furthermore, the radar constant of the cloud radar can be calibrated using aircraft observation data. For example, select 1-2 warm cloud cases that are also observed by aircraft, and have the aircraft conduct circling observations to obtain layered cloud droplet spectrum data from cloud base to cloud top. The data is then brought into the cloud radar equation to calibrate the radar constant of the cloud radar. The radar constant is related to the radar itself and can be calibrated every three months or six months to obtain a stable and reliable value.

[0069] It should be noted that the echo attenuation parameters are different at different detection heights.

[0070] After substituting various radar parameters and echo attenuation parameters into the cloud radar equation, the output value is β c The value of (Z) is the first backscattering coefficient of the target detection layer.

[0071] S104: Set a first radar ratio.

[0072] When setting the first radar ratio, you can randomly select from the radar ratio optional range to set it; you can also set it according to demand.

[0073] S105. Apply the first radar ratio to determine a second backscattering coefficient of the inverted cloud droplet spectrum corresponding to the laser radar and the target detection layer.

[0074] When determining the second backscattering coefficient of the inverted cloud droplet spectrum corresponding to the laser radar and the target detection layer, it is necessary to first determine the second extinction coefficient corresponding to the laser radar and the target detection layer. The specific process is as follows:

[0075] S301, determine whether the target detection layer is the first detection layer in the cloud; if the target detection layer is the first detection layer in the cloud, execute S302; if the target detection layer is not the first detection layer in the cloud, execute S305.

[0076] The second extinction coefficient of the first detection layer in the cloud is obtained in a different manner from the second extinction coefficient of other detection layers. The process of obtaining the second extinction coefficient of the first detection layer refers to S302-S303; the process of obtaining the second extinction coefficient of other detection layers is such as S304.

[0077] S302: Obtain laser raw data from the laser radar, process the laser raw data, and obtain the aerosol extinction coefficient and aerosol backscattering coefficient from the ground to the cloud base.

[0078] Based on various preset correction elements, the lidar raw data is corrected to obtain the standard backscattering signal; various operation parameters are obtained; various operation parameters and the standard backscattering signal are processed to obtain the aerosol backscattering coefficient and aerosol extinction coefficient from the ground to the cloud base.

[0079] It should be noted that the various correction elements include but are not limited to delay correction, background noise correction, post-pulse correction, overlap factor correction, distance correction, etc., among which delay correction, background noise correction, post-pulse correction and overlap factor correction all belong to radar factor correction.

[0080] The part from the ground to the cloud base is all aerosol. When processing various calculation parameters and standard backscattering signals to obtain the aerosol extinction coefficient and aerosol backscattering coefficient from the ground to the cloud base, the distance from the ground to the cloud base can be layered, and then the proximal solution and layer-by-layer recursive method can be used from low to high to invert the aerosol backscattering coefficient and aerosol extinction coefficient of the cloud base.

[0081] The various operation parameters include but are not limited to the first detection height of the laser radar, the atmospheric molecule backscattering coefficient, the atmospheric molecule radar ratio, the radar constant of the laser radar, and the radar transmission power of the laser radar; the air molecule backscattering coefficient and the air molecule radar ratio can be used to calculate the vertical expansion line according to the air molecule density of the national standard atmospheric model. The aerosol is evenly distributed in the blind area, and the initial aerosol extinction coefficient is obtained as the initial value of the proximal solution by observing the ground visibility or the aerosol particle size spectrometer, and it is recursively upward layer by layer until the cloud base.

[0082] Substituting the standard backscatter signal and various operation parameters into the preset forward integration scheme for operation, the aerosol backscatter coefficient can be output. Furthermore, the equation of the forward integration scheme is expressed as:

[0083]

[0084] Among them, C L0 represents the radar constant of the laser radar, P L0 represents the radar transmission power of the lidar, β a is the aerosol backscattering coefficient, β m is the atmospheric molecular backscattering coefficient, S a is the aerosol radar ratio, S m is the atmospheric molecular radar ratio, Z is the detection height of the lidar, and X(z) is the standard backscatter signal. It should be noted that, in general, the aerosol radar ratio ranges from 10 to 90 sr.

[0085] S303: Process the aerosol backscattering coefficient and the first radar ratio to obtain a second extinction coefficient corresponding to the laser radar and the target detection layer.

[0086] Preferably, the aerosol backscattering coefficient and the first radar ratio are multiplied, and the resulting value is the second extinction coefficient corresponding to the laser radar and the target detection layer.

[0087] S304, processing the first radar ratio and the second backscattering coefficient of the upper detection layer in the cloud located at the target detection layer to obtain a second extinction coefficient corresponding to the laser radar and the target detection layer.

[0088] Preferably, the upper detection layer of the target detection layer in the cloud is used as the application detection layer, and then the second backscattering coefficient of the application detection layer is multiplied by the first radar ratio, and the obtained value is the second extinction coefficient corresponding to the laser radar and the target detection layer.

[0089] The second backscatter coefficient of the applied detection layer is the second backscatter coefficient of the laser radar in the applied detection layer.

[0090] Furthermore, after determining the second backscattering coefficient of the inverted cloud droplet spectrum corresponding to the laser radar and the target detection layer, it is necessary to process the second extinction coefficient to obtain the second backscattering coefficient of the laser radar in the target detection layer. The specific process is described as follows.

[0091] Determine each second radar parameter of the laser radar; calculate the second extinction coefficient and each second radar parameter to obtain a second backscattering coefficient of the target detection layer.

[0092] The second radar parameters of the laser radar include but are not limited to the radar receiving power of the laser radar, the radar constant of the laser radar, the radar transmitting power of the laser radar, and the detection height.

[0093] The radar equation of the laser radar is applied to process each second radar parameter and the second extinction coefficient to obtain the second backscattering coefficient.

[0094] The radar equation for lidar is expressed as:

[0095]

[0096] Among them, P L is the radar receiving power of the laser radar, C L0 is the radar constant of the laser radar, P L0 is the radar transmission power of the laser radar, β L is the backscattering coefficient, σ L is the extinction coefficient, and Z is the detection height. The radar constant C of the laser radarL0 The calibration selects cloudless and somewhat polluted atmospheric conditions. Further, by substituting each second radar parameter and the second extinction coefficient into the radar equation for calculation, the second backscattering coefficient can be obtained, which is β output by the radar equation. L is the second backscattering coefficient. It should be noted that σ L is the second extinction coefficient of the target detection layer.

[0097] S106. Determine the backscattering ratio based on the first backscattering coefficient and the second backscattering coefficient.

[0098] Dividing the first backscattering coefficient of the target detection layer by the second backscattering coefficient can obtain the backscattering ratio of the target detection layer.

[0099] S107. Determine the effective cloud droplet diameter and cloud droplet spectrum distribution corresponding to the backscattering ratio, and determine the second radar ratio corresponding to the effective cloud droplet diameter and cloud droplet spectrum distribution.

[0100] When determining the effective cloud droplet diameter and cloud droplet spectrum distribution corresponding to the backscattering ratio, the effective cloud droplet diameter and cloud droplet spectrum distribution corresponding to the backscattering ratio can be obtained based on the theoretical basis of the inversion algorithm supporting this solution. After obtaining the effective cloud droplet diameter and cloud droplet spectrum distribution, the second radar ratio can be calculated using the effective cloud droplet diameter and cloud droplet spectrum distribution.

[0101] The inversion algorithm provided by the present invention is based on the Mie theory, so it mainly considers the spectral characteristics of liquid-phase cloud droplets. To explain the theoretical basis of the inversion algorithm of the present invention, it is assumed that the cloud droplet spectrum satisfies the Γ distribution, and the modified Γ distribution is adopted. The formula expression of the droplet spectrum distribution is as follows:

[0102] n(r) = N0r μ e -ωr

[0103] Among them, N0 is the intercept parameter, μ is the spectral shape parameter, ω is the slope factor, and n(r) is the cloud droplet number concentration.

[0104] According to the physical meaning of different order moments of the droplet spectrum, the relationship between the effective cloud droplet diameter and the droplet spectrum parameters is deduced. This relationship can be expressed by an equation, which is specifically as follows:

[0105]

[0106] Among them, M represents the order moment, M3 represents the third moment, M2 represents the second moment, and R eff is the effective diameter. As mentioned above, μ generally takes an integer, and the range is 2 - 9. Thus, the relationship between the effective cloud droplet diameter of the cloud droplet spectrum and the droplet spectrum distribution function is established.

[0107] Exemplarily, the typical cloud droplet scale ranges from a few micrometers to hundreds of micrometers, and the characteristic scale is generally about 10 μm. Therefore, for cloud droplets with a radius within 100 μm, there is a certain relationship between the ratio of the backscattering coefficients at wavelengths of 8600 μm (typical band of cloud radar) and 0.532 μm (typical wavelength of lidar) derived based on Mie scattering theory (hereinafter referred to as the backscattering ratio) and the effective particle size. And for different μ values, it is not sensitive when the particle size is greater than 2.5 μm. An example diagram of the relationship between the effective particle size and the backscattering ratio under different μ conditions is as shown in Figure 3 shown. The relationship between the backscattering ratio and the effective cloud droplet size is the bridge established between the inversion algorithm of the present invention and the observed data, which is the core of the present invention. Based on the solution provided by the present invention, the cloud droplet spectrum can be inverted by introducing the backscattering ratios of two radars.

[0108] S108. Determine whether the absolute value of the difference between the first radar ratio and the second radar ratio is greater than a preset threshold. When the absolute value of the difference between the first radar ratio and the second radar ratio is not greater than the preset threshold, return to execute S104; when the absolute value of the difference between the first radar ratio and the second radar ratio is greater than the preset threshold, execute S109.

[0109] It should be noted that the first radar ratio and the second radar ratio are subtracted to obtain the difference between them, and then the absolute value of this difference is obtained. The preset threshold can be set according to actual needs. The obtained absolute value is compared with the preset threshold to determine whether the absolute value is greater than the preset threshold. It should be noted that when returning to execute S104, the first radar ratio set when returning is different from the previous first radar ratio. Returning to execute S104 can be understood as resetting the first radar ratio.

[0110] This is an iterative process. The meaning of iteration is to continuously narrow the difference between the first radar ratio and the second radar ratio. When the difference reduction value between the two is within the threshold range, the iteration ends, and the cloud droplet spectrum information of this detection layer is obtained, and then the cloud droplet spectrum information of the next detection layer is continued to be determined.

[0111] S109. Determine the cloud droplet effective particle size and the cloud droplet spectrum distribution as the cloud droplet spectrum information of the target detection layer. Further, after determining the cloud droplet effective particle size and the cloud droplet spectrum distribution as the cloud droplet spectrum information of the target detection, the first extinction coefficient of the target detection layer can also be determined based on the second radar ratio and the first backscattering coefficient; it should be noted that the radar ratio is the value of the extinction coefficient divided by the backscattering coefficient. After knowing the second radar ratio and the first backscattering coefficient, the corresponding first extinction coefficient can be obtained.

[0112] S110. Determine whether the detection altitude has reached the maximum observation altitude of the lidar. When the detection altitude has not reached the maximum observation altitude of the lidar, execute S111; when the detection altitude has reached the maximum observation altitude of the lidar, execute S112.

[0113] Compare the detection altitude with the maximum observation altitude of the lidar. When the detection altitude is less than the maximum observation altitude of the lidar, it is determined that the detection altitude has not reached the maximum observation altitude of the lidar, and at this time, iteration needs to continue. When the detection altitude is greater than or equal to the maximum observation altitude of the lidar, the cloud droplet spectrum information of the vertical distribution of the observed cloud can be obtained at this time.

[0114] S111. Determine the next detection layer in the cloud located in the target detection layer as the new target detection layer, and then return to execute S102.

[0115] When the detection altitude is less than the maximum observation altitude of the lidar, the next detection layer in the cloud located in the target detection layer needs to be used as the new target detection layer, and then return to execute S102. Thus, layer-by-layer iteration is performed as the altitude increases until the maximum observation altitude of the lidar is reached, and then the cloud droplet spectrum information of the vertical distribution is obtained.

[0116] S112. End.

[0117] In the method provided by the embodiment of the present invention, the first detection layer in the cloud is used as the target detection layer for inverting the cloud droplet spectrum, and the detection height corresponding to the target detection layer is determined. The cloud is divided into multiple detection layers from the cloud bottom to the cloud top according to a preset layer height, and the detection layer containing the cloud bottom in the cloud is the first detection layer in the cloud; determine the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer; process the echo attenuation parameter to obtain the first backscattering coefficient of the inverted cloud droplet spectrum corresponding to the target detection layer; set the first radar ratio; apply the first radar ratio to determine the second backscattering coefficient of the inverted cloud droplet spectrum corresponding to the lidar and the target detection layer; based on the first backscattering coefficient and the second backscattering coefficient, determine the backscattering ratio; determine the effective cloud droplet diameter and the cloud droplet spectrum distribution corresponding to the backscattering ratio, and determine the second radar ratio corresponding to the effective cloud droplet diameter and the cloud droplet spectrum distribution; when the absolute value of the difference between the first radar ratio and the second radar ratio is not greater than the preset threshold, return to execute the step of setting the first radar ratio; when the absolute value of the difference between the first radar ratio and the second radar ratio is greater than the preset threshold, determine the effective cloud droplet diameter and the cloud droplet spectrum distribution as the cloud droplet spectrum information of the target detection layer, and when the detection height does not reach the maximum observation height of the lidar, determine the detection layer behind the target detection layer in the cloud as the new target detection layer, and then return to execute the step of determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer. The present invention performs inversion operations on the data of the lidar and the cloud radar, and layer by layer determines the effective cloud droplet diameter and the cloud droplet spectrum distribution of the cloud, so that the information of the effective diameter and the cloud droplet spectrum distribution of the vertically distributed cloud droplets can be obtained. This process does not require an aircraft equipped with a cloud particle probe to pass through different parts of the cloud to obtain the cloud droplet spectrum information, effectively reducing the cost of obtaining the cloud droplet spectrum information.

[0118] The solution provided by the present invention uses ground-based remote sensing instruments to invert the effective cloud droplet diameter and the vertical distribution of the cloud droplet spectrum. The ground observation equipment used in the present invention is mainly a Ka-band cloud radar (wavelength 8.6 mm) and a micropulse lidar (wavelength 532 nm), and the vertical resolution of both is 30 m. In addition, a ground aerosol size spectrometer and a visibility meter are also used.

[0119] The inversion algorithm applied by the present invention to invert the effective cloud droplet diameter and the cloud droplet spectrum distribution is based on the Mie theory. The content of the theoretical basis of the inversion algorithm provided by the present invention refers to the relevant description above. Refer to Figure 4 , which is an example diagram for determining the effective diameter and the spectral shape parameters by using the correlation between the spectral shape parameters and the color ratio established by the Mie theory provided by the embodiment of the present invention. The figure includes the content of establishing the correlation between the spectral shape parameters and the color ratio by using the Mie theory, and the content of obtaining the backscattering coefficient ratio by using the inversion algorithm. Then, based on the backscattering coefficient ratio and the correlation between the spectral shape parameters and the color ratio, the effective diameter and the spectral shape parameters are determined.

[0120] In the process of determining the cloud droplet spectrum information provided by the present invention, an inversion algorithm is used for determination. The inversion algorithm provided by the present invention needs to first determine the backscattering coefficient of the lidar-inverted cloud droplet spectrum (equivalent to the second backscattering coefficient mentioned above). Determining the backscattering of the lidar-inverted cloud droplet spectrum is divided into two steps. The first step is to calculate the aerosol backscattering coefficient and aerosol extinction coefficient from the ground to the cloud base. The second step is to calculate the cloud droplet spectrum backscattering coefficient.

[0121] The process of calculating the aerosol backscattering coefficient and aerosol extinction coefficient from the ground to the cloud base can refer to the above content and will not be described here.

[0122] In the process of calculating the cloud droplet spectrum backscattering coefficient, the lidar radar equation mentioned above is used, and then the aerosol vertical backscattering coefficient and extinction coefficient are obtained according to the first step until the cloud base. Starting from the cloud base as the first layer of cloud droplet spectrum inversion, assuming a given cloud droplet spectrum radar ratio (different radar ratios correspond to different effective particle sizes and spectral distributions), substituting it into the lidar radar equation and comparing it with the cloud radar equation, the effective particle size of the cloud droplet spectrum and the cloud droplet spectrum distribution are obtained according to the proposed algorithm. Calculate the new radar ratio according to the cloud droplet spectrum and compare it with the previous assumption. Whether the difference between the two reaches a certain threshold range. If not, change the assumed radar ratio and iteratively calculate the new spectral distribution until the difference between the two is reduced to the threshold range and the iteration ends. According to this method, iterate layer by layer as the height increases. The radar ratio and backscattering coefficient of each layer can be obtained. The specific process is as Figure 5 shown, referring to Figure 5 , which is the flowchart of the lidar method for inverting the backscattering coefficient of the cloud droplet spectrum provided by the embodiment of the present invention.

[0123] It should be noted that Figure 5 the process shown is also the process of determining the effective particle size of cloud droplets and the cloud droplet spectrum distribution of the cloud layer by layer. When determining the effective particle size of cloud droplets and the cloud droplet spectrum distribution, in addition to applying the backscattering coefficient of the lidar-inverted cloud droplet spectrum, it is also necessary to use the backscattering coefficient of the cloud radar-inverted cloud droplet spectrum (equivalent to the first backscattering coefficient described above).

[0124] In the process of retrieving the backscattering coefficient of the cloud droplet size spectrum using the cloud radar, the radar equation of the cloud radar described above is used for processing. In the process of retrieving the cloud droplet size spectrum, the present invention assumes that there is no attenuation of the cloud radar signal below the cloud base, and a layer-by-layer iterative method is used to retrieve the backscattering coefficient and extinction coefficient. If there is only scattering without attenuation in the first layer, then there is only one unknown, i.e., the backscattering coefficient, after the equation is simplified. The backscattering coefficient of the first layer can be obtained based on the received power of the radar (referred to as echo information here). By comparing with the backscattering coefficient of the lidar and based on the previously introduced theoretical basis, the effective particle size and cloud droplet size spectrum information of the first layer can be obtained. Based on this, the extinction coefficient of the cloud droplets causing scattering in the first layer is further calculated, which is used as the attenuation cause of the echo in the second layer. Calculate layer by layer in this way until the effective height observed by the lidar is reached. The effective height observed by the lidar is the height with the highest effective signal-to-noise ratio that the lidar can detect.

[0125] To verify the feasibility of the solution for obtaining cloud droplet size spectrum information provided by the present invention, the forward calculation results of the inversion method in the present invention are provided for comparative demonstration.

[0126] Based on the above theoretical basis, assuming that the aerosol vertical spectrum distribution and cloud droplet vertical spectrum distribution are known, if two radars simultaneously observe this atmospheric feature, the theoretical echo powers measured by each layer of the cloud radar and lidar can be calculated respectively based on the radar equation.

[0127] The parameters set for each height layer are the same, as shown in the standard distribution parameters in Table 1. There are a total of 17 preset given height layers, with a vertical resolution of 100 m. Below 1000 m is the aerosol layer, and the cloud base height is 1000 m. That is, the actual height of the cloud is 1000 - 1700 m. The vertical distribution diagrams of the lidar echo, cloud radar echo, and cloud radar reflectivity factor obtained by forward calculation according to the inversion algorithm are as Figures 6(a) to 6(c) , Figure 6(a) is an example diagram of the echo signal of the lidar after range correction, Figure 6(b) is an example diagram of the echo signal of the cloud radar, and Figure 6(c) is an example diagram of the vertical distribution of the cloud radar reflectivity factor.

[0128] Table 1 Parameters set for each height layer and retrieved parameters

[0129]

[0130] Furthermore, the line graphs of the effective particle size and number concentration of cloud droplets obtained by inverting the lidar echo and cloud radar echo are as Figures 7(a) to 7(b), when performing inversion calculations on lidar echoes and cloud radar echoes, the values shown in Table 1 can be used for the calculations. Figure 7(a) is an example diagram of the standard vertical distribution and inversion result of the effective particle size. The Std line in the figure is the standard vertical distribution of the effective particle size, and the Retrieval line is the inversion result of the effective particle size; Figure 7(b) is an example diagram of the standard vertical distribution and inversion result of the number concentration. The Std line in the figure is the standard vertical distribution of the number concentration, and the Retrieval line is the inversion result of the number concentration. From Figures 7(a) to 7(b) it can be seen that the inversion results are relatively consistent with the standard vertical distribution, and the correlation coefficient for the entire layer is as high as 98%. The difference is mainly manifested in the 8th layer, which may be related to the accumulation of errors with height.

[0131] In fact, due to the limitations of the equipment itself in remote sensing observations, there are certain errors in the actually observed echo power. A random error is added to the actually measured echo power based on the theoretical calculated value, considering that the actual equipment observation error is within ±10%, and a ±10% random error is introduced. The effective particle size and cloud droplet spectrum of each layer are inverted using the above method and compared with the cloud droplet spectrum distribution inverted from the initial assumptions and standard parameters.

[0132] A ±5% and ±10% random error is added to the lidar echo signal, and 30 samples are selected for inversion. The results are shown in Figures 8(a) to 11(d) .

[0133] Figures 8(a) to 8(d) Figure 8 is an example diagram of adding a 5% random error (30) to the range-corrected lidar echo intensity and the inversion results. Figure 8(a) is an example diagram of the lidar echo intensity with ±5% random error and without random error distribution. Figure 8(b) is an example diagram of the cloud radar echo signal. Figure 8(c) is an example diagram of the inverted effective particle size. Figure 8(d) is an example diagram of the inverted number concentration.

[0134] Figures 9(a) to 9(d) Figure 9 is an example diagram of adding a 10% random error (30) to the range-corrected lidar echo intensity and the inversion results. Figure 9(a) is an example diagram of the lidar echo intensity with ±10% random error and without random error distribution. Figure 9(b) is an example diagram of the cloud radar echo signal. Figure 9(c) is an example diagram of the inverted effective particle size. Figure 9(d) is an example diagram of the inverted number concentration.

[0135] Figures 10(a) to 10(d) Figure 10 is an example diagram of adding a 5% random error (30) to the cloud radar echo signal and the inversion results. Figure 10(a) is an example diagram of the cloud radar echo signal with ±5% random error and without random error distribution. Figure 10(b) is an example diagram of the range-corrected lidar echo intensity. Figure 10(c) is an example diagram of the inverted effective particle size. Figure 10(d) is an example diagram of the inverted number concentration.

[0136] Figures 11(a) to 11(d) Example diagrams of adding 10% random errors (30 in number) to cloud radar echo signals and the inversion results. Figure 11(a) is an example diagram of the distribution of cloud radar echo signals with ±10% random errors and without random errors. Figure 11(b) is an example diagram of the echo intensity of the range-corrected lidar. Figure 11(c) is an example diagram of the retrieved effective particle size. Figure 11(d) is an example diagram of the retrieved number concentration.

[0137] ±5% and ±10% random errors are added to the lidar echo signal, and 30 samples are randomly selected for inversion. The results are shown in Figures 8(a) to 9(d) . Figures 9(a) to 9(d) The deviation of the average value of the effective particle size from the standard inversion value in [] increases from 0.07% in the first layer to 107% in the sixth layer, increasing sharply with height, but decreasing to 13.4% in the seventh layer. The root mean square deviation of the samples increases from ±4.2% to ±32%. The average deviation of the overall inversion results increases with height and also increases with the increase of the effective particle size. Statistics show that 100% of the sample cases in the first and second layers have an error range within ±10%. As the height increases, 87% of the cases in the third and fourth layers have an error range within ±40%, and 87% of the cases in the fifth and sixth layers have an error range within ±80%. Therefore, the lidar echo error has a greater impact on the inversion results. The greater the random error, the greater the error of the inversion results, and it increases rapidly with height. The characteristics of the retrieved number concentration are similar to those of the effective particle size. Therefore, the numerical dispersion of the effective particle size and number concentration retrieved by this method increases significantly with height.

[0138] Figures 8(a) to 8(d) The distribution of all samples and the variation trend with height are similar to those of Figures 9(a) to 9(d) , and the inversion results, error range, and numerical dispersion are all lower than those of Figures 9(a) to 9(d) .

[0139] Similarly, when different random errors (±5% and ±10%) are added to the cloud radar echo signal as shown in Figures 10(a) to 11(d) , the retrieved effective particle size and number concentration show a variation trend with height similar to that of adding random errors to the lidar echo signal, but their inversion results and error range are better than those based on the lidar random errors.

[0140] Therefore, according to Figures 8(a) to 11(d) , it can be seen that under the same conditions, based on the lidar echo signal with random errors, the deviation of the retrieved effective particle size and number concentration is higher than the inversion results based on the cloud radar echo signal with random errors. The observation errors of both the lidar and the cloud radar can cause errors in the inversion results to a certain extent, and the deviation of the inversion results increases with height. When there are observation errors in both, the inversion results of the cloud droplet spectrum closer to the cloud base are more reliable.

[0141] Therefore, according to the evaluation of the above inversion algorithm, the inversion algorithm can very well give the vertical distribution parameters of the cloud droplet size spectrum, including the effective cloud droplet diameter and the number concentration. The relative deviation of the effective cloud droplet diameter increases with height. The relative deviations of the first to fifth layers are 0.0%, and the relative deviations of the sixth, seventh, and eighth layers are 1%, 2.5%, and 70% respectively, and the inversion results are on the high side. The relative deviations of the number concentration of the first to fourth layers are 0.0%, and those of the fifth, sixth, seventh, and eighth layers are -0.1%, -6.3%, -13.8%, and -95.7% respectively, and the inversion results are on the low side. Therefore, the inversion results of the first to seventh layers are completely credible.

[0142] After introducing random errors into the lidar and cloud radar respectively, the deviation of the inversion result increases with the increase of the error and with the increase of height. That is to say, as the error increases, the credibility of the result inverted by this algorithm decreases with the increase of height. The number of height layers with specific inversion credibility depends on the size of the error, and the part closer to the cloud base has higher credibility.

[0143] Therefore, the inversion method for jointly inverting the effective cloud droplet diameter and the vertical distribution of the cloud droplet size spectrum based on the cloud radar and lidar proposed by the present invention can demonstrate the algorithm from the aspects of theoretical basis, forward inversion, and inverse inversion respectively, obtain reliable inversion results through feasibility analysis, and then obtain cloud droplet size spectrum information. The core principle of the present invention is the difference in the scattering characteristics of the same cloud particle at different radar wavelengths, and an association between this difference and the vertical distribution of the cloud droplet size spectrum is established.

[0144] Applying the present invention to obtain cloud droplet size spectrum information can provide more understanding of the effective cloud droplet diameter and the vertical distribution of the cloud droplet size spectrum in the cloud droplet size spectrum information, and enhance the understanding of cloud microphysical processes; the cloud droplet size spectrum information acquisition scheme provided by the present invention provides a reference for the urgent needs of researching and improving the parameterization scheme of cloud microphysical process numerical simulation, artificial weather modification technology, and remote sensing quantitative precipitation estimation, and reduces the cost of obtaining cloud droplet size spectrum information. Moreover, the method of jointly inverting the cloud droplet size spectrum (not relying on the power spectrum data of the cloud radar) using the cloud radar and lidar is very worthy of trial and use. There is no relevant research report at present, and this multi-band radar remote sensing joint inversion method of cloud droplet size spectrum has great application potential.

[0145] Corresponding to Figure 1 the method shown, an apparatus for jointly inverting cloud droplet size spectrum information by a cloud radar and a lidar is provided in an embodiment of the present invention. This apparatus is used to support Figure 1 the specific implementation of the method shown. This apparatus can be set in a ground-based remote sensing system. Referring to Figure 12 , it is a schematic structural diagram of an apparatus for jointly inverting cloud droplet size spectrum information by a cloud radar and a lidar provided in an embodiment of the present invention, which is specifically described as follows.

[0146] The first determination unit 401 is configured to use the first detection layer in the cloud as the target detection layer for inverting the cloud droplet spectrum, and determine the detection height corresponding to the target detection layer. The cloud is divided into multiple detection layers from the cloud bottom to the cloud top according to a preset layer height, and the detection layer including the cloud bottom in the cloud is the first detection layer in the cloud;

[0147] The second determination unit 402 is configured to determine the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer;

[0148] The first acquisition unit 403 is configured to process the echo attenuation parameter to obtain the first backscattering coefficient of the inverting cloud droplet spectrum corresponding to the target detection layer;

[0149] The setting unit 404 is configured to set a first radar ratio;

[0150] The third determination unit 405 is configured to apply the first radar ratio to determine the second backscattering coefficient of the inverting cloud droplet spectrum corresponding to the lidar and the target detection layer;

[0151] The fourth determination unit 406 is configured to determine a backscattering ratio based on the first backscattering coefficient and the second backscattering coefficient;

[0152] The fifth determination unit 407 is configured to determine the effective cloud droplet diameter and the cloud droplet spectrum distribution corresponding to the backscattering ratio, and determine the second radar ratio corresponding to the effective cloud droplet diameter and the cloud droplet spectrum distribution; when the absolute value of the difference between the first radar ratio and the second radar ratio is not greater than a preset threshold, return to execute the step of setting the first radar ratio; when the absolute value of the difference between the first radar ratio and the second radar ratio is greater than the preset threshold, determine the effective cloud droplet diameter and the cloud droplet spectrum distribution as the cloud droplet spectrum information of the target detection layer, and when the detection height does not reach the highest observation height of the lidar, determine the next detection layer in the cloud located at the target detection layer as the new target detection layer, and then return to execute the step of determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer.

[0153] The present invention performs inversion operations on the data of the lidar and the cloud radar, and layer by layer determines the effective cloud droplet diameter and the cloud droplet spectrum distribution of the cloud, so that the information on the effective cloud droplet diameter and the cloud droplet spectrum distribution with vertical distribution can be obtained. This process does not require an aircraft equipped with a cloud particle probe to travel through different parts of the cloud to obtain the cloud droplet spectrum information, effectively reducing the cost of obtaining the cloud droplet spectrum information.

[0154] The device provided by the embodiment of the present invention further includes:

[0155] A sixth determination unit, configured to determine a first extinction coefficient of the target detection layer based on the second radar ratio and the first backscattering coefficient.

[0156] In the apparatus provided by an embodiment of the present invention, the second determination unit of the apparatus includes:

[0157] A judgment subunit, configured to judge whether the target detection layer is the first detection layer in the cloud;

[0158] A first determination subunit, configured to, if the target detection layer is the first detection layer in the cloud, determine that an echo attenuation parameter corresponding to the cloud radar and the target detection layer is zero;

[0159] A second determination subunit, configured to, if the target detection layer is not the first detection layer in the cloud, determine a first extinction coefficient of a detection layer preceding the target detection layer in the cloud as an echo attenuation parameter corresponding to the cloud radar and the target detection layer.

[0160] In the apparatus provided by an embodiment of the present invention, the first acquisition unit of the apparatus includes:

[0161] A third determination subunit, configured to determine respective first radar parameters of the cloud radar;

[0162] An operation subunit, configured to perform an operation on the echo attenuation parameter and each of the radar parameters to obtain a first backscattering coefficient of an inversion droplet spectrum corresponding to the target detection layer.

[0163] In the apparatus provided by an embodiment of the present invention, the third determination unit 405 of the apparatus includes:

[0164] A fourth determination subunit, configured to apply the first radar ratio to determine a second extinction coefficient corresponding to the lidar and the target detection layer;

[0165] A first acquisition subunit, configured to process the second extinction coefficient to obtain a second backscattering coefficient of the lidar at the target detection layer.

[0166] In the apparatus provided by an embodiment of the present invention, the fourth determination subunit of the apparatus includes:

[0167] A judgment subunit, configured to judge whether the target detection layer is the first detection layer in the cloud;

[0168] A second acquisition subunit, configured to, if the target detection layer is the first detection layer in the cloud, acquire original lidar data, process the original lidar data to obtain an aerosol extinction coefficient and an aerosol backscattering coefficient from the ground to the cloud base;

[0169] The first processing subunit is configured to process the aerosol backscattering coefficient and the first lidar ratio to obtain the second extinction coefficient corresponding to the lidar and the target detection layer;

[0170] The second processing subunit is configured to, if the target detection layer is not the first detection layer in the cloud, process the first lidar ratio and the second backscattering coefficient of the upper detection layer of the cloud located in the target detection layer to obtain the second extinction coefficient corresponding to the lidar and the target detection layer.

[0171] In the device provided by the embodiment of the present invention, the second acquisition subunit of the device includes:

[0172] The correction module is configured to correct the original lidar data based on each preset correction element to obtain a standard backscattering signal;

[0173] The acquisition module is configured to acquire each operation parameter;

[0174] The processing module is configured to process each of the operation parameters and the standard backscattering signal to obtain the aerosol backscattering coefficient and the aerosol extinction coefficient from the ground to the cloud base.

[0175] The embodiment of the present invention further provides a storage medium, which includes stored instructions. When the instructions run, the device where the storage medium is located is controlled to execute the method for jointly inverting cloud droplet spectrum information by a cloud radar and a lidar as described above.

[0176] The embodiment of the present invention further provides an electronic device, the structural schematic diagram of which is as Figure 13 shown, and specifically includes a memory 601 and one or more instructions 602. One or more instructions 602 are stored in the memory 601 and are configured to be executed by one or more processors 603 to execute the method for jointly inverting cloud droplet spectrum information by a cloud radar and a lidar as described above.

[0177] It should be noted that the information and data involved in this application are all information and data authorized by users or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant laws, regulations, and standards of relevant countries and regions. The specific implementation processes and their derivative methods of the above various embodiments are all within the protection scope of the present invention.

[0178] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for a system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple. For the relevant parts, reference can be made to the description of the method embodiment. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative work.

[0179] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Skilled professionals can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0180] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for jointly retrieving cloud droplet spectrum information by cloud radar and lidar, characterized in that, Including: Taking the first detection layer in the cloud as the target detection layer for inverting the cloud droplet spectrum, and determining the detection height corresponding to the target detection layer. The cloud is divided into multiple detection layers from the cloud bottom to the cloud top according to a preset layer height, and the detection layer including the cloud bottom in the cloud is the first detection layer in the cloud; Determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer; Processing the echo attenuation parameter to obtain the first backscattering coefficient of the inverting cloud droplet spectrum corresponding to the target detection layer; Setting a first radar ratio; Applying the first radar ratio to determine the second backscattering coefficient of the inverting cloud droplet spectrum corresponding to the lidar and the target detection layer; Based on the first backscattering coefficient and the second backscattering coefficient, determining the backscattering ratio; Determining the effective cloud droplet diameter and the cloud droplet spectrum distribution corresponding to the backscattering ratio, and determining the second radar ratio corresponding to the effective cloud droplet diameter and the cloud droplet spectrum distribution; When the absolute value of the difference between the first radar ratio and the second radar ratio is not greater than a preset threshold, returning to execute the step of setting the first radar ratio; When the absolute value of the difference between the first radar ratio and the second radar ratio is greater than the preset threshold, determining the effective cloud droplet diameter and the cloud droplet spectrum distribution as the cloud droplet spectrum information of the target detection layer, and when the detection height does not reach the highest observation height of the lidar, determining the next detection layer in the cloud located at the target detection layer as the new target detection layer, and then returning to execute the step of determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer.

2. The method according to claim 1, wherein When the absolute value of the difference between the first radar ratio and the second radar ratio is greater than the preset threshold, it further includes: Based on the second radar ratio and the first backscattering coefficient, determining the first extinction coefficient of the target detection layer.

3. The method according to claim 2, wherein The determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer includes: Judging whether the target detection layer is the first detection layer in the cloud; If the target detection layer is the first detection layer in the cloud, determining the echo attenuation parameter corresponding to the cloud radar and the target detection layer as zero; If the target detection layer is not the first detection layer in the cloud, determining the first extinction coefficient of the previous detection layer in the cloud located at the target detection layer as the echo attenuation parameter corresponding to the cloud radar and the target detection layer.

4. The method according to claim 1, characterized in that, The processing the echo attenuation parameter to obtain the first backscattering coefficient of the inverting cloud droplet spectrum corresponding to the target detection layer includes: Determining each first radar parameter of the cloud radar; Performing an operation on the echo attenuation parameter and each of the first radar parameters to obtain the first backward scattering coefficient of the inverting droplet spectrum corresponding to the target detection layer.

5. The method according to claim 1, wherein The applying the first radar ratio to determine the second backscattering coefficient of the inverting cloud droplet spectrum corresponding to the lidar and the target detection layer includes: Applying the first radar ratio to determine the second extinction coefficient corresponding to the lidar and the target detection layer; Process the second extinction coefficient to obtain the second backscattering coefficient of the lidar in the target detection layer.

6. The method according to claim 5, characterized in that, The application of the first radar ratio to determine the second extinction coefficient corresponding to the lidar and the target detection layer includes: Determine whether the target detection layer is the first detection layer in the cloud; If the target detection layer is the first detection layer in the cloud, obtain the original lidar data, process the original lidar data to obtain the aerosol extinction coefficient and aerosol backscattering coefficient from the ground to the cloud base; Process the aerosol backscattering coefficient and the first radar ratio to obtain the second extinction coefficient corresponding to the lidar and the target detection layer; If the target detection layer is not the first detection layer in the cloud, process the first radar ratio and the second backscattering coefficient of the upper detection layer of the target detection layer in the cloud to obtain the second extinction coefficient corresponding to the lidar and the target detection layer.

7. The method according to claim 6, wherein The processing of the original lidar data to obtain the aerosol extinction coefficient and aerosol backscattering coefficient from the ground to the cloud base includes: Based on each preset correction element, correct the original lidar data to obtain a standard backscattering signal; Obtain each operation parameter; Process each operation parameter and the standard backscattering signal to obtain the aerosol backscattering coefficient and aerosol extinction coefficient from the ground to the cloud base.

8. An apparatus for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar, characterized in that, Includes: A first determination unit for using the first detection layer in the cloud as the target detection layer for inverting the cloud droplet spectrum and determining the detection height corresponding to the target detection layer. The cloud is divided into multiple detection layers from the cloud base to the cloud top according to a preset layer height, and the detection layer including the cloud base in the cloud is the first detection layer in the cloud; A second determination unit for determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer; A first acquisition unit for processing the echo attenuation parameter to obtain the first backscattering coefficient of the inverting cloud droplet spectrum corresponding to the target detection layer; A setting unit for setting the first radar ratio; A third determination unit for applying the first radar ratio to determine the second backscattering coefficient of the inverting cloud droplet spectrum corresponding to the lidar and the target detection layer; A fourth determination unit for determining the backscattering ratio based on the first backscattering coefficient and the second backscattering coefficient; A fifth determination unit, configured to determine an effective cloud droplet diameter and a cloud droplet spectrum distribution corresponding to the backscattering ratio, and determine a second radar ratio corresponding to the effective cloud droplet diameter and the cloud droplet spectrum distribution; when the absolute value of the difference between the first radar ratio and the second radar ratio is not greater than a preset threshold, return to execute the step of setting the first radar ratio; when the absolute value of the difference between the first radar ratio and the second radar ratio is greater than the preset threshold, determine the effective cloud droplet diameter and the cloud droplet spectrum distribution as the cloud droplet spectrum information of the target detection layer, and when the detection height does not reach the highest observation height of the lidar, determine the next detection layer of the cloud located in the target detection layer as the new target detection layer, and then return to execute the step of determining the echo attenuation parameter corresponding to the preset cloud radar and the target detection layer.

9. A storage medium, characterized in that, The storage medium includes stored instructions, wherein when the instructions are running, the device where the storage medium is located is controlled to execute the method for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar according to any one of claims 1-7.

10. An electronic device, characterized in that, It includes a memory, and one or more instructions, wherein one or more instructions are stored in the memory and are configured to be executed by one or more processors to execute the method for jointly retrieving cloud droplet spectrum information by a cloud radar and a lidar according to any one of claims 1-7.

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