Method for evaluating effect of artificial influence on streaming cloud based on radar automatic tracking algorithm

Abstract

The invention relates to an artificial influence convection cloud effect evaluation method based on a radar automatic tracking algorithm, which relates to the technical field of meteorological radar, and is characterized in that according to the basic condition of artificial influence weather operation, a paired convection cloud artificial influence weather operation method is adopted to delimit the areas of operation catalysis cloud and comparison cloud, and the areas are taken as the areas of interest, the catalytic cloud and the comparison cloud form paired convection clouds, weather radar three-dimensional digital networking is carried out for a region of interest, quality control and three-dimensional coordinate conversion are carried out on collected radar data, CAPPI data are generated based on the radar data, circular regions of the same size are selected in the region of interest, and the circular regions are distributed in the region of interest. The method comprises the following steps: respectively surrounding cloud body areas where catalytic clouds and contrast clouds are located, automatically tracking the movement of cloud systems in circular areas by adopting a radar echo correlation tracking algorithm, carrying out statistical analysis on radar echo physical parameters in each circular area, and carrying out statistical analysis on the difference of the catalytic clouds and the contrast clouds on the radar echo parameters. And evaluating the actual effect of the artificial influence weather operation.

Description

Technical Field

[0001] The invention relates to the technical field of meteorological radars, and more particularly to an artificially influenced convective cloud effect evaluation method based on a radar automatic tracking algorithm. Background Art

[0002] With the continuous development of meteorological science, the study of cloud physics and meteorological impact plays an important role in global climate change and extreme weather prediction. In this context, artificial weather modification has become an important means to alleviate drought and improve meteorological conditions. By applying artificial stimulation to the clouds, the condensation of water vapor in the clouds can be accelerated, thereby enhancing precipitation. However, the physical process of clouds is complex and dynamic, which makes the evaluation of the effect of artificial influence crucial.

[0003] As an important tool in modern meteorological observation technology, radar automatic tracking algorithm is widely used to monitor the movement, shape and intensity changes of clouds. Radar can track the spatial position, intensity distribution and movement trajectory of meteorological clouds in real time and with high precision, which provides a large amount of data support for studying the effects of artificial weather modification. By combining multi-dimensional information such as radar reflectivity, velocity profile, and echo intensity, the changing characteristics of artificially affected convective clouds can be more accurately evaluated. Especially in the evolution of convective clouds, the automatic tracking algorithm can identify the artificially affected area and accurately analyze the differences in clouds before and after artificial intervention. Summary of the invention

[0004] The present invention aims at the technical problems existing in the prior art and provides an artificially influenced convective cloud effect evaluation method based on a radar automatic tracking algorithm to solve the problems raised in the above background technology.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a method for evaluating the effect of artificially influenced convective clouds based on a radar automatic tracking algorithm, specifically comprising the following steps:

[0006] Step 101: According to the basic situation of the artificial weather modification operation, the paired convective cloud artificial weather modification operation method is adopted to delineate the areas of the operation catalytic cloud and contrast cloud as the focus area, wherein the catalytic cloud and contrast cloud constitute paired convective clouds;

[0007] Step 102: Perform three-dimensional digital networking of weather radars for the area of ​​interest, perform quality control and three-dimensional coordinate conversion on the collected radar data, and generate CAPPI data based on the radar data;

[0008] Step 103: select circular areas of equal size in the focus area to surround the cloud areas where the catalytic cloud and the comparison cloud are located, respectively, and automatically track the movement of the cloud system in the circular area using the radar echo correlation tracking algorithm based on the generated CAPPI data;

[0009] Step 104: Statistically analyze the physical parameters of the radar echoes in each circular area, and evaluate the actual effect of the artificial weather modification operation by analyzing the difference in radar echo parameters between the catalytic cloud and the comparison cloud.

[0010] In a preferred embodiment, in step 101, according to the basic situation of the artificial weather modification operation, the paired convective cloud artificial weather modification operation method is adopted to delineate the areas of the operation catalytic cloud and the contrast cloud as the focus area, wherein the catalytic cloud and the contrast cloud constitute a paired convective cloud, and the specific steps are as follows:

[0011] Step A1, establishing a database: constructing a database server to store the geographical information and meteorological data of the weather modification operation sites, including the station name, station number, longitude and latitude, altitude, operation equipment type, operation time, wind direction and wind speed;

[0012] Step A2, delineating the area of ​​interest: extracting the site information with operation records from the database, and delineating the area of ​​the operation target cloud and the comparison cloud based on the longitude and latitude, altitude, operation equipment type, operation time and meteorological data of the site, and taking it as the area of ​​interest;

[0013] The catalytic cloud area is defined based on the latitude, longitude and altitude information of the target site. This area is located downwind to facilitate the evaluation of the effect of artificial weather modification operations. The longitude and latitude of the target site are expressed as (lat T ,lon T ), altitude h T , wind speed v and wind direction angle θ are obtained from meteorological data wind , the wind direction angle is 0° to the north and clockwise to the positive direction, and the range of the catalytic cloud area is represented by the radius p 1 , coordinates (x 1 ,y 1 ) is calculated as follows:

[0014]

[0015]

[0016] The comparison cloud area is defined based on the latitude, longitude and altitude information of the selected comparison cloud site. This area is located in the upwind direction to facilitate comparative analysis. The range of the catalytic cloud area is represented by the radius p 2 , coordinates (x 2 ,y 2 ) is calculated as follows:

[0017]

[0018]

[0019] Among them, (lon C ,lon C ) is the latitude and longitude of the central site of the comparison cloud region.

[0020] In a preferred embodiment, in step 102, a three-dimensional digital network of weather radars is performed for the area of ​​interest, quality control and three-dimensional coordinate conversion are performed on the collected radar data, and CAPPI data is generated based on the radar data. The specific steps are as follows:

[0021] Step B1, radar data collection: radar stations are deployed in the area of ​​interest for data collection. The location of each radar station is (x radar ,y radar ,z radar ), in three-dimensional space, based on the position of the radar site and the radar scanning range, a three-dimensional grid is constructed, which is represented as a three-dimensional grid defined by azimuth angle θ, pitch angle φ, scanning distance r and altitude h, and radar data is obtained by scanning each grid in the target area;

[0022] Step B2, quality control and coordinate conversion: filtering, correcting, and deblurring the collected radar data to eliminate clutter and noise, improve data quality, and convert the polar coordinate data (r, θ, φ) of the radar into three-dimensional coordinates in a Cartesian coordinate system;

[0023] Step B3, generate CAPPI data: CAPPI is a two-dimensional graph showing the radar echo intensity, with a fixed height h CAPPI , calculated according to the radar base data corresponding to the height h CAPPI For each target point, the radar echo intensity Z(r,θ,φ) is calculated at a specific height h. CAPPI Project it onto the height plane to get the echo intensity of the point at that height. The specific calculation formula is as follows:

[0024]

[0025] Where Z(r,θ,φ) is the echo intensity measured by the radar station at the scanning distance r, azimuth angle θ and elevation angle φ. CAPPI (x,y,h CAPPI ) represents the height z in the CAPPI plane CAPPI On, point (x 3 ,y 3 ) echo intensity, Z i is the echo intensity of the ith point, h i is the altitude of the ith point; (h CAPPI -hi ) is an indicator function, when h i Equal to the target height h CAPPI When it returns 1, it means that the echo intensity of the point is projected onto the target height plane.

[0026] In a preferred embodiment, in step 103, circular areas of equal size are selected in the region of interest to respectively surround the cloud areas where the catalytic cloud and the contrast cloud are located, and based on the generated CAPPI data, a radar echo correlation tracking algorithm is used to automatically track the movement of the cloud system in the circular area. The specific steps are as follows:

[0027] Step C1, select the cloud area: set the circular area surrounding the catalytic cloud as C c and the circular area C surrounding the contrast cloud d , and their center points are (x c ,y c ) and (x d ,y d ), the radius is ε, and the mathematical expression of the circular area of ​​the catalytic cloud is: The mathematical expression of the circular area of ​​the contrast cloud is: Where (x, y) is the coordinate of a point in the radar echo graph;

[0028] Step C2, radar echo correlation calculation: set at time T 1 Circular area C c The radar echo data is Z 1 (x,y,T 1 ), at time T 2 Circular area C d The radar echo strength is Z 2 (x,y,T 2 ), the mutual correlation coefficient between the two circular areas is expressed as follows:

[0029]

[0030] in, and They are circular areas C c and C d The mean value of the radar echo intensity, (x,y)∈C c and (x,y)∈C d Represents the circular area C c and C d The pixel coordinates within, C(t 1 ,t 2 ) is the correlation coefficient, which indicates the similarity of the echo intensity between two moments;

[0031] Step C3, calculate cloud movement: by calculating the correlation coefficient between different time steps, find the best matching area, that is, the position with the largest correlation coefficient, set it at time T 1 and time T 2 Between, the cloud body is in (x 0 ,y 0 ) The changes in position are Δx and Δy, and the moving speed of the cloud is calculated by the following formula:

[0032]

[0033]

[0034] Among them, argmax means finding the correlation coefficient C(T 1 ,T 2 ) maximum (x,y) coordinate, indicating the maximum displacement of the cloud in the x and y directions,

[0035] Step C4, update cloud position: after calculating the displacement Δx and Δy of the cloud each time, update the circular area position of the catalytic cloud and the comparison cloud. Suppose the circular area center positions of the catalytic cloud and the comparison cloud at the current moment are (x c ,y c ) and (x d ,y d ), at the next moment T 2 , the updated center positions of the catalytic cloud and the comparison cloud are:

[0036] (x' c ,y' c )=(xc+Δx,yc+Δy)

[0037] (x' d ,y' d )=(xd+Δx,yd+Δy)

[0038] Among them, (x' c ,y' c ) and (x' d ,y' d ) are the updated positions of the centers of the catalytic cloud and the comparison cloud, respectively, Δx and Δy are the displacements of the cloud bodies;

[0039] Step C5, iterative tracking: Repeat steps C1 to C4, continue to track the movement of the cloud, update the position of the circular area each time, and recalculate the correlation. When the calculated correlation coefficient C(T 1 ,T 2 ) is less than the set threshold of 0.7, the tracking is stopped.

[0040] In a preferred embodiment, in step 104, the physical parameters of the radar echoes in each circular area are statistically analyzed, and the actual effect of the artificial weather modification operation is evaluated by analyzing the difference in radar echo parameters between the catalytic cloud and the comparison cloud. The specific steps are as follows:

[0041] Step D1: Statistical analysis of physical parameters: In each selected catalytic cloud region C c And compared with cloud region C d Collect radar data, including reflectivity factor Q, Doppler velocity V e , spectral width σ v , and calculate the mean values ​​of physical parameters in the catalytic cloud and comparison cloud areas. The specific calculation formula is as follows:

[0042] Catalytic Cloud Region C c :

[0043] Compare Cloud Region C d :

[0044] Among them, N c and N d are the number of data points in the catalytic cloud and comparison cloud regions, respectively. and are the mean reflectivity factors in the catalytic cloud and contrast cloud regions, and are the mean Doppler velocities in the catalytic cloud and contrast cloud regions, and are the average spectral widths in the catalytic cloud and contrast cloud regions, Q(x ζ ,y ζ ), V e (x ζ ,y ζ ),σ v (x ζ ,y ζ ) represent the catalytic cloud region C c Inside, coordinate (x ζ ,y ζ ) position reflectivity factor, Doppler velocity and spectral width, Q(x τ ,y τ ), V e (x τ ,y τ ),σ v (x τ ,y τ ) represent the catalytic cloud region C d Inside, coordinate (x τ ,yτ ) location reflectivity factor, Doppler velocity and spectral width;

[0045] Step D2, statistical significance test: Calculate the differences in reflectivity factor, Doppler velocity and spectral width between the catalytic cloud and the contrast cloud area, respectively: The significance level is set to α, and the t-test method is used to perform a statistical significance test. The specific calculation formula is as follows:

[0046]

[0047] Where ΔQ is the difference in reflectivity between the catalytic cloud and the contrast cloud area, s u is the pooled standard deviation of the sample: where s c and d are the sample standard deviations of the catalytic cloud and comparison cloud regions, respectively, and N c and N d are the number of data points in the catalytic cloud and contrast cloud regions respectively. The critical value at the significance level α is obtained by looking up the t distribution table. It shows that the reflectivity factor is significantly different. It shows that the difference in reflectivity factor is not significant;

[0048] By the same steps, we can obtain and when It shows that the Doppler velocity difference is significant. It shows that the difference of Doppler velocity is not significant; when It shows that the spectral width is significantly different. This indicates that the difference in spectral width is not significant;

[0049] Step D3, evaluate the effect of artificial weather modification operations: Combined with the analysis results of the above steps, evaluate the actual effect of artificial weather modification operations. When the physical parameters of the catalytic cloud area are significantly higher than those of the comparison cloud area, it indicates that the artificial weather modification measures are effective. When the difference is not significant, it indicates that the artificial weather modification operations have not achieved the expected results, and further analysis and improvement are needed.

[0050] The beneficial effects of the present invention are as follows: according to the basic situation of artificial weather influencing operation, the paired convective cloud artificial weather influencing operation method is adopted, the area of ​​the operation catalytic cloud and contrast cloud is delineated, and the area is taken as the focus area, wherein the catalytic cloud and contrast cloud constitute a paired convective cloud, three-dimensional digital networking of weather radar is performed for the focus area, the collected radar data is quality controlled and three-dimensional coordinate converted, CAPP I data is generated based on the radar data, circular areas of equal size are selected in the focus area to respectively surround the cloud body areas where the catalytic cloud and contrast cloud are located, according to the generated CAPP I data, a radar echo correlation tracking algorithm is adopted to automatically track the movement of the cloud system in the circular area, the physical parameters of the radar echo in each circular area are statistically analyzed, the actual effect of the artificial weather influencing operation is evaluated by analyzing the difference in radar echo parameters between the catalytic cloud and the contrast cloud, and by analyzing different meteorological conditions and artificial intervention effects, the development and change of convective clouds can be analyzed more scientifically and reasonably, the effect of artificial weather influencing operation can be evaluated more objectively, and technical guidance is provided for scientific and precise artificial weather influencing operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0053] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0054] In the description of the present application, the term "for example" is used to mean "used as an example, illustration or description". Any embodiment described as "for example" in the present application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is given to enable any technician in the field to implement and use the present invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present invention can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid unnecessary details to obscure the description of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present application.

[0055] Example 1

[0056] This embodiment provides Figure 1 The method for evaluating the effect of artificially influenced convective clouds based on the radar automatic tracking algorithm specifically includes the following steps:

[0057] Step 101: Based on the basic situation of the weather modification operation, the paired convective cloud weather modification operation method is adopted to delineate the areas of the catalytic cloud and the contrast cloud as the focus area, wherein the catalytic cloud and the contrast cloud constitute a paired convective cloud;

[0058] Step 102: Perform three-dimensional digital networking of weather radars for the area of ​​interest, perform quality control and three-dimensional coordinate conversion on the collected radar data, and generate CAPPI data based on the radar data;

[0059] Step 103: select circular areas of equal size in the area of ​​interest to respectively surround the cloud areas where the catalytic cloud and the comparison cloud are located, and automatically track the movement of the cloud system in the circular area using a radar echo correlation tracking algorithm based on the generated CAPP I data;

[0060] Step 104: Statistically analyze the physical parameters of the radar echoes in each circular area, and evaluate the actual effect of the artificial weather modification operation by analyzing the difference in radar echo parameters between the catalytic cloud and the comparison cloud.

[0061] Preferably, in step 101, according to the basic situation of the artificial weather modification operation, the paired convective cloud artificial weather modification operation method is adopted to delineate the areas of the operation catalytic cloud and contrast cloud as the focus area, wherein the catalytic cloud and contrast cloud constitute paired convective cloud, and the specific steps are as follows:

[0062] Step A1, establishing a database: constructing a database server to store the geographical information and meteorological data of the weather modification operation sites, including the station name, station number, longitude and latitude, altitude, operation equipment type, operation time, wind direction and wind speed;

[0063] Step A2, delineating the area of ​​interest: extracting the site information with operation records from the database, and delineating the area of ​​the operation target cloud and the comparison cloud based on the longitude and latitude, altitude, operation equipment type, operation time and meteorological data of the site, and taking it as the area of ​​interest;

[0064] The catalytic cloud area is defined based on the latitude, longitude and altitude information of the target site. This area is located downwind to facilitate the evaluation of the effect of artificial weather modification operations. The longitude and latitude of the target site are expressed as (lat T ,lon T ), altitude h T , wind speed v and wind direction angle θ are obtained from meteorological data wind , the wind direction angle is 0° to the north and clockwise to the positive direction, and the range of the catalytic cloud area is represented by the radius p 1 , coordinates (x 1 ,y 1 ) is calculated as follows:

[0065]

[0066]

[0067] The comparison cloud area is defined based on the latitude, longitude and altitude information of the selected comparison cloud site. This area is located in the upwind direction to facilitate comparative analysis. The range of the catalytic cloud area is represented by the radius p 2 , coordinates (x 2 ,y 2 ) is calculated as follows:

[0068]

[0069]

[0070] Among them, (lon C ,lon C ) is the latitude and longitude of the central site of the comparison cloud region.

[0071] Preferably, in step 102, a three-dimensional digital network of weather radars is performed for the area of ​​interest, quality control and three-dimensional coordinate conversion are performed on the collected radar data, and CAPPI data is generated based on the radar data. The specific steps are as follows:

[0072] Step B1, radar data collection: radar stations are deployed in the area of ​​interest for data collection. The location of each radar station is (x radar ,y radar ,z radar ), in three-dimensional space, based on the position of the radar site and the radar scanning range, a three-dimensional grid is constructed, which is represented as a three-dimensional grid defined by azimuth angle θ, pitch angle φ, scanning distance r and altitude h, and radar data is obtained by scanning each grid in the target area;

[0073] Step B2, quality control and coordinate conversion: filtering, correcting, and deblurring the collected radar data to eliminate clutter and noise, improve data quality, and convert the polar coordinate data (r, θ, φ) of the radar into three-dimensional coordinates in a Cartesian coordinate system;

[0074] Step B3, generate CAPPI data: The CAPPI is a two-dimensional graph showing the intensity of radar echoes, indicating the intensity of radar echoes at a fixed height. The fixed height is set to h. CAPPI , calculated according to the radar base data corresponding to the height h CAPPI For each target point, the radar echo intensity Z(r,θ,φ) is calculated at a specific height h. CAPPI Project it onto the height plane to get the echo intensity of the point at that height. The specific calculation formula is as follows:

[0075]

[0076] Where Z(r,θ,φ) is the echo intensity measured by the radar station at the scanning distance r, azimuth angle θ and elevation angle φ. CAPPI (x,y,h CAPPI ) represents the height z in the CAPPI plane CAPPI On, point (x 3 ,y 3 ) echo intensity, Z i is the echo intensity of the ith point, h i is the altitude of the ith point; (h CAPPI -h i ) is an indicator function, when h i Equal to the target height h CAPPI When it returns 1, it means that the echo intensity of the point is projected onto the target height plane.

[0077] Preferably, in step 103, circular areas of equal size are selected in the region of interest to respectively surround the cloud areas where the catalytic cloud and the comparison cloud are located, and based on the generated CAPPI data, a radar echo correlation tracking algorithm is used to automatically track the movement of the cloud system in the circular area. The specific steps are as follows:

[0078] Step C1, select the cloud area: set the circular area surrounding the catalytic cloud as C c and the circular area C surrounding the contrast cloud d , and their center points are (x c ,y c ) and (x d ,y d ), the radius is ε, and the mathematical expression of the circular area of ​​the catalytic cloud is: The mathematical expression of the circular area of ​​the contrast cloud is: Where (x, y) is the coordinate of a point in the radar echo graph;

[0079] Step C2, radar echo correlation calculation: set at time T 1 Circular area C c The radar echo data is Z 1 (x,y,T 1 ), at time T 2 Circular area C d The radar echo strength is Z 2 (x,y,T 2 ), the mutual correlation coefficient between the two circular areas is expressed as follows:

[0080]

[0081] in, and They are circular areas C c and C d The mean value of the radar echo intensity, (x,y)∈C c and (x,y)∈C d Represents the circular area C c and C d The pixel coordinates within, C(t 1 ,t 2 ) is the correlation coefficient, which indicates the similarity of the echo intensity between two moments;

[0082] Step C3, calculate cloud movement: by calculating the correlation coefficient between different time steps, find the best matching area, that is, the position with the largest correlation coefficient, set it at time T 1 and time T 2 Between, the cloud body is in (x 0 ,y 0 ) The changes in position are Δx and Δy, and the moving speed of the cloud is calculated by the following formula:

[0083]

[0084]

[0085] Among them, argmax means finding the correlation coefficient C(T 1 ,T 2 ) maximum (x,y) coordinate, indicating the maximum displacement of the cloud in the x and y directions,

[0086] Step C4, update cloud position: after calculating the displacement Δx and Δy of the cloud each time, update the circular area position of the catalytic cloud and the comparison cloud. Suppose the circular area center positions of the catalytic cloud and the comparison cloud at the current moment are (x c ,y c ) and (x d ,y d ), at the next moment T 2 , the updated center positions of the catalytic cloud and the comparison cloud are:

[0087] (x' c ,y' c )=(xc+Δx,yc+Δy)

[0088] (x' d ,y' d )=(xd+Δx,yd+Δy)

[0089] Among them, (x' c ,y' c ) and (x' d ,y' d ) are the updated positions of the centers of the catalytic cloud and the comparison cloud, respectively, Δx and Δy are the displacements of the cloud bodies;

[0090] Step C5, iterative tracking: Repeat steps C1 to C4, continue to track the movement of the cloud, update the position of the circular area each time, and recalculate the correlation. When the calculated correlation coefficient C(T 1 ,T 2 ) is less than the set threshold of 0.7, the tracking is stopped.

[0091] Preferably, in step 104, the physical parameters of the radar echoes in each circular area are statistically analyzed, and the actual effect of the artificial weather modification operation is evaluated by analyzing the difference in radar echo parameters between the catalytic cloud and the contrast cloud. The specific steps are as follows:

[0092] Step D1: Statistical analysis of physical parameters: In each selected catalytic cloud region C c And compared with cloud region C d Collect radar data, including reflectivity factor Q, Doppler velocity V e , spectral width σ v, and calculate the mean values ​​of physical parameters in the catalytic cloud and the contrast cloud areas, the reflectivity factor represents the precipitation intensity and cloud characteristics, the Doppler velocity represents the moving speed of precipitation particles, and the spectrum width represents the velocity distribution of precipitation particles;

[0093] Catalytic Cloud Region C c :

[0094] Compare Cloud Region C d :

[0095] Among them, N c and N d are the number of data points in the catalytic cloud and comparison cloud regions, respectively. and are the mean reflectivity factors in the catalytic cloud and contrast cloud regions, and are the mean Doppler velocities in the catalytic cloud and contrast cloud regions, and are the average spectral widths in the catalytic cloud and contrast cloud regions, Q(x ζ ,y ζ ), V e (x ζ ,y ζ ),σ v (x ζ ,y ζ ) represent the catalytic cloud region C c Inside, coordinate (x ζ ,y ζ ) position reflectivity factor, Doppler velocity and spectral width, Q(x τ ,y τ ), V e (x τ ,y τ ),σ v (x τ ,y τ ) represent the catalytic cloud region C d Inside, coordinate (x τ ,y τ ) location reflectivity factor, Doppler velocity and spectral width;

[0096] Step D2, statistical significance test: Calculate the differences in reflectivity factor, Doppler velocity and spectral width between the catalytic cloud and the contrast cloud area, respectively: The significance level is set to α, and the t-test method is used to perform a statistical significance test. The specific calculation formula is as follows:

[0097]

[0098] Where ΔQ is the difference in reflectivity between the catalytic cloud and the contrast cloud area, s u is the pooled standard deviation of the sample: where s c and d are the sample standard deviations of the catalytic cloud and comparison cloud regions, respectively, and N c and N d are the number of data points in the catalytic cloud and contrast cloud regions respectively. The critical value at the significance level α is obtained by looking up the t distribution table. It shows that the reflectivity factor is significantly different. It shows that the difference in reflectivity factor is not significant;

[0099] By the same steps, we can obtain and when It shows that the Doppler velocity difference is significant. It shows that the difference of Doppler velocity is not significant; when It shows that the spectral width is significantly different. This indicates that the difference in spectral width is not significant;

[0100] Step D3, evaluate the effect of artificial weather modification operations: Combined with the analysis results of the above steps, evaluate the actual effect of artificial weather modification operations. When the physical parameters of the catalytic cloud area are significantly higher than those of the comparison cloud area, it indicates that the artificial weather modification measures are effective. When the difference is not significant, it indicates that the artificial weather modification operations have not achieved the expected results, and further analysis and improvement are needed.

[0101] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0102] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0103] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0104] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0105] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0106] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0107] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for evaluating the effect of artificially influenced convective clouds based on radar automatic tracking algorithm, characterized in that: The specific steps include: Step 101: According to the basic situation of the artificial weather modification operation, the paired convective cloud artificial weather modification operation method is adopted to delineate the areas of the operation catalytic cloud and contrast cloud as the focus area, wherein the catalytic cloud and contrast cloud constitute paired convective clouds; Step 102: Perform three-dimensional digital networking of weather radars for the area of ​​interest, perform quality control and three-dimensional coordinate conversion on the collected radar data, and generate CAPPI data based on the radar data; Step 103: select circular areas of equal size in the focus area to surround the cloud areas where the catalytic cloud and the comparison cloud are located, respectively, and automatically track the movement of the cloud system in the circular area using the radar echo correlation tracking algorithm based on the generated CAPPI data; Step 104: Statistically analyze the physical parameters of the radar echoes in each circular area, and evaluate the actual effect of the artificial weather modification operation by analyzing the difference in radar echo parameters between the catalytic cloud and the comparison cloud.

2. The method for evaluating the effect of artificially influenced convective clouds based on radar automatic tracking algorithm according to claim 1 is characterized in that: In step 101, according to the basic situation of the artificial weather modification operation, the paired convective cloud artificial weather modification operation method is adopted to delineate the areas of the operation catalytic cloud and the contrast cloud as the focus area, wherein the catalytic cloud and the contrast cloud constitute a paired convective cloud. The specific steps are as follows: Step A1, establishing a database: constructing a database server to store the geographical information and meteorological data of the weather modification operation sites, including the station name, station number, longitude and latitude, altitude, operation equipment type, operation time, wind direction and wind speed; Step A2, delineate the area of ​​interest: extract the site information with operation records from the database, and delineate the area of ​​the operation target cloud and the comparison cloud based on the latitude and longitude, altitude, operation equipment type, operation time and meteorological data of the site, and use it as the area of ​​interest.

3. The method for evaluating the effect of artificially influenced convective clouds based on radar automatic tracking algorithm according to claim 2 is characterized in that: The catalytic cloud area is defined based on the latitude, longitude and altitude information of the target site; the latitude and longitude of the target site are expressed as (lat T ,lon T ), altitude h T , wind speed v and wind direction angle θ are obtained from meteorological data wind , the range of the catalytic cloud area is represented as radius p1, and the calculation formula of the catalytic cloud area at the coordinate (x1, y1) is as follows: The comparison cloud area is defined according to the latitude, longitude and altitude information of the selected comparison cloud site. The range of the catalytic cloud area is represented as radius p2. The calculation formula of the comparison cloud area at the coordinate (x2, y2) is as follows: Among them, (lon C ,lon C ) is the latitude and longitude of the central site of the comparison cloud area.

4. The method for evaluating the effect of artificially influenced convective clouds based on radar automatic tracking algorithm according to claim 1, characterized in that: In step 102, a three-dimensional digital network of weather radars is performed for the area of ​​interest, quality control and three-dimensional coordinate conversion are performed on the collected radar data, and CAPPI data is generated based on the radar data. The specific steps are as follows: Step B1, radar data collection: radar stations are deployed in the area of ​​interest for data collection. The location of each radar station is (x radar ,y radar ,z radar ), in three-dimensional space, based on the position of the radar site and the radar scanning range, a three-dimensional grid is constructed, which is represented as a three-dimensional grid defined by azimuth angle θ, pitch angle φ, scanning distance r and altitude h, and radar data is obtained by scanning each grid in the target area; Step B2, quality control and coordinate conversion: filtering, correcting, and deblurring the collected radar data to eliminate clutter and noise, improve data quality, and convert the polar coordinate data (r, θ, φ) of the radar into three-dimensional coordinates in a Cartesian coordinate system; Step B3, generate CAPPI data: CAPPI is a two-dimensional graph showing the radar echo intensity, with a fixed height h CAPPI , calculated according to the radar base data corresponding to the height h CAPPI For each target point, the radar echo intensity Z(r,θ,φ) is calculated at a specific height h. CAPPI Project it onto the height plane to get the echo intensity of the point at that height. The specific calculation formula is as follows: Where Z(r,θ,φ) is the echo intensity measured by the radar station at the scanning distance r, azimuth angle θ and elevation angle φ. CAPPI (x,y,h CAPPI ) represents the height z in the CAPPI plane CAPPI The echo intensity of point (x3, y3), Z i is the echo intensity of the ith point, h i is the altitude of the ith point; (h CAPPI -h i ) is an indicator function, when h i Equal to the target height h CAPPI When it returns 1, it means that the echo intensity of the point is projected onto the target height plane.

5. The method for evaluating the effect of artificially influenced convective clouds based on radar automatic tracking algorithm according to claim 1, characterized in that: In step 103, circular areas of equal size are selected in the area of ​​interest to respectively surround the cloud areas where the catalytic cloud and the contrast cloud are located, and the movement of the cloud system in the circular area is automatically tracked using the radar echo correlation tracking algorithm based on the generated CAPPI data. The specific steps are as follows: Step C1, select the cloud area: set the circular area surrounding the catalytic cloud as C c and the circular area C surrounding the contrast cloud d , and their center points are (x c ,y c ) and (x d ,y d ), the radius is ε, and the mathematical expression of the circular area of ​​the catalytic cloud is: The mathematical expression of the circular area of ​​the contrast cloud is: Where (x, y) is the coordinate in the radar echo map; Step C2, radar echo correlation calculation: set the circular area C at time T1 c The radar echo data is Z1(x,y,T1). At time T2, the circular area C d The radar echo intensity is Z2(x,y,T2), and the correlation coefficient between the two circular areas is expressed as follows: in, and They are circular areas C c and C d The mean value of the radar echo intensity, (x,y)∈C c and (x,y)∈C d Represents the circular area C c and C d The pixel coordinates within, C(t1, t2) is the correlation coefficient, which indicates the similarity of the echo intensity between the two moments; Step C3, calculate the movement of the cloud body: by calculating the correlation coefficient between different time steps, find the best matching area, that is, the position with the largest correlation coefficient. Suppose that between time T1 and time T2, the change of the cloud body at the position (x0, y0) is Δx and Δy, and the movement speed of the cloud body is calculated by the following formula: Among them, argmax means finding the (x,y) coordinates that maximize the correlation coefficient C(T1,T2), which represents the maximum displacement of the cloud in the x and y directions. Step C4, update cloud position: after calculating the displacement Δx and Δy of the cloud each time, update the circular area position of the catalytic cloud and the comparison cloud. Suppose the circular area center positions of the catalytic cloud and the comparison cloud at the current moment are (x c ,y c ) and (x d ,y d ), at the next moment T2, the updated center positions of the catalytic cloud and the comparison cloud are: (x' c ,y' c )=(xc+Δx,yc+Δy) (x' d ,y' d )=(xd+Δx,yd+Δy) Among them, (x' c ,y' c ) and (x' d ,y' d ) are the updated positions of the centers of the catalytic cloud and the comparison cloud, respectively, Δx and Δy are the displacements of the cloud bodies; Step C5, iterative tracking: Repeat steps C1 to C4, continuously track the movement of the cloud, update the position of the circular area each time, and recalculate the correlation. When the calculated correlation coefficient C(T1, T2) is less than the set threshold of 0.7, stop tracking.

6. The method for evaluating the effect of artificially influenced convective clouds based on radar automatic tracking algorithm according to claim 1, characterized in that: In step 104, the physical parameters of the radar echoes in each circular area are statistically analyzed, and the actual effect of the artificial weather modification operation is evaluated by analyzing the difference in radar echo parameters between the catalytic cloud and the contrast cloud. The specific steps are as follows: Step D1: Statistical analysis of physical parameters: In each selected catalytic cloud region C c And compared with cloud region C d Collect radar data, including reflectivity factor Q, Doppler velocity V e , spectral width σ v , and calculate the mean values ​​of physical parameters in the catalytic cloud and comparison cloud areas; Step D2, statistical significance test: Calculate the differences in reflectivity factor, Doppler velocity and spectral width between the catalytic cloud and the contrast cloud area, respectively: The significance level is set to α, and the t-test method is used to perform a statistical significance test. The specific calculation formula is as follows: Where ΔQ is the difference in reflectivity between the catalytic cloud and the contrast cloud area, s u is the pooled standard deviation of the sample: where s c and d are the sample standard deviations of the catalytic cloud and comparison cloud regions, respectively, and N c and N d are the number of data points in the catalytic cloud and contrast cloud regions respectively. The critical value at the significance level α is obtained by looking up the t distribution table. It shows that the reflectivity factor is significantly different. It shows that the difference in reflectivity factor is not significant; By the same steps, we can obtain and when It shows that the Doppler velocity difference is significant. It shows that the difference of Doppler velocity is not significant; when It shows that the spectral width is significantly different. This indicates that the difference in spectral width is not significant; Step D3, evaluate the effect of artificial weather modification operations: Combined with the analysis results of the above steps, evaluate the actual effect of artificial weather modification operations. When the physical parameters of the catalytic cloud area are significantly higher than those of the comparison cloud area, it indicates that the artificial weather modification measures are effective. When the difference is not significant, it indicates that the artificial weather modification operations have failed to achieve the expected results and need to be analyzed and improved.

7. The method for evaluating the effect of artificially influenced convective clouds based on radar automatic tracking algorithm according to claim 6, characterized in that: The specific calculation formula for calculating the mean values ​​of physical parameters in the catalytic cloud and comparison cloud regions is as follows: For the catalytic cloud region C c : For the comparison cloud area C d : Among them, N c and N d are the number of data points in the catalytic cloud and comparison cloud regions, respectively. and are the mean reflectivity factors in the catalytic cloud and contrast cloud regions, and are the mean Doppler velocities in the catalytic cloud and contrast cloud regions, and are the average spectral widths in the catalytic cloud and contrast cloud regions, Q(x ζ ,y ζ ), V e (x ζ ,y ζ ),σ v (x ζ ,y ζ ) represent the catalytic cloud region C c Inside, coordinate (x ζ ,y ζ ) position reflectivity factor, Doppler velocity and spectral width, Q(x τ ,y τ ), V e (x τ ,y τ ),σ v (x τ ,y τ ) represent the catalytic cloud region C d Inside, coordinate (x τ ,y τ ) position reflectivity factor, Doppler velocity and spectral width.

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