A method and system for identifying atmospheric rivers based on domestic hyperspectral satellites

Abstract

The present invention discloses an atmospheric river identification method and system based on a domestic hyperspectral satellite. The related method includes: smoothing the global water vapor column total data set and eliminating tropical water vapor interference, and then performing preliminary identification of atmospheric river events. If it is initially identified as an atmospheric river event, the atmospheric river occurrence area is divided; the threshold is determined by using the multi-year inter-annual water vapor column total distribution in the atmospheric river occurrence area, and the atmospheric river path is extracted from the atmospheric river occurrence area using the threshold; the atmospheric river axis is calculated using the pixel points corresponding to the highest water vapor column total in the atmospheric river path, and the atmospheric river axis is used to determine whether it belongs to a cyclone system; if it does, it indicates that the initially identified atmospheric river event is a misjudgment; if it does not, it indicates that the atmospheric river event is finally identified. The above scheme can realize fully automatic atmospheric river identification on a global scale without cumbersome image refinement processing, and can also filter out interference from other strong water vapor transport events caused by non-atmospheric rivers.

Description

Technical Field

[0001] The present invention relates to the field of geophysics, and in particular to an atmospheric river identification method and system based on a domestically produced hyperspectral satellite. Background Art

[0002] Atmospheric rivers are narrow water vapor transport belts located in the lower part of the troposphere. They usually occur in mid- and high-latitudes and originate from tropical and subtropical oceans. They can transport a large amount of water vapor to mid- and high-latitude regions. Atmospheric rivers cover less than 1 / 10 of the earth's circumference, but account for more than 9 / 10 of the total water vapor transported from mid-latitudes to the poles, and are a key factor in the generation of heavy precipitation and floods. Therefore, for the study of global extreme hydrological events, accurate identification of atmospheric river events is particularly important. The current definition of atmospheric rivers is: "a narrow and short corridor of strong horizontal water vapor transport, usually associated with the low-level jet stream in front of the cold front of an extratropical cyclone." Since this definition does not specify the specific values ​​of the length, width, and water vapor transport of atmospheric rivers, but emphasizes the morphological characteristics of atmospheric rivers and their correlation with weather systems, it is not conducive to identifying atmospheric river events. Therefore, it is necessary to quantify the morphological characteristics of atmospheric rivers. It is generally believed that the area where the water vapor transport direction points from the equator to high latitudes, the length is greater than 2000km, the width is less than 1000km, and the total water vapor column is greater than 2cm is the area where atmospheric rivers occur.

[0003] The water vapor data that can be used to identify atmospheric river events include: (1) the total water vapor column observed by satellite; (2) the water vapor flux simulated by the model. Existing comparison results show that the number and morphology of atmospheric rivers identified by the two types of data are almost the same, proving the feasibility of using the total water vapor column observed by satellite to identify atmospheric river events. However, the current atmospheric river event identification scheme has the following main technical problems: (1) It is impossible to achieve fully automatic identification on a global scale; (2) It involves relatively cumbersome image refinement processing; (3) There is interference from other strong water vapor transport events, which affects the accuracy of atmospheric river event identification. Summary of the invention

[0004] The purpose of the present invention is to provide an atmospheric river identification method and system based on domestic hyperspectral satellites, which is a global, fully automatic atmospheric river identification solution that does not require cumbersome image refinement processing and can also filter out interference from other strong water vapor transport events caused by non-atmospheric rivers.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] An atmospheric river identification method based on domestic hyperspectral satellite, comprising:

[0007] Obtain the global water vapor column data set using domestic satellite hyperspectral inversion, smooth the global water vapor column data set and exclude tropical water vapor interference to obtain the corrected global water vapor column data set;

[0008] The atmospheric river events are preliminarily identified from the revised global water vapor column data set. If they are preliminarily identified as atmospheric river events, the atmospheric river occurrence areas are divided.

[0009] Determine a threshold value using the multi-year inter-annual water vapor column distribution in the atmospheric river occurrence region, and extract the atmospheric river path from the atmospheric river occurrence region using the threshold value;

[0010] The atmospheric river axis is calculated using the pixel points corresponding to the highest total water vapor column in the atmospheric river path, and the atmospheric river axis is used to determine whether it belongs to a cyclone system; if it belongs to a cyclone system, it indicates that the initially identified atmospheric river event is a misjudgment; if it does not belong to a cyclone system, it indicates that the atmospheric river event was finally identified.

[0011] An atmospheric river identification system based on domestic hyperspectral satellites, including:

[0012] The data acquisition and correction unit is used to obtain the global water vapor column data set using domestic satellite hyperspectral inversion, smooth the global water vapor column data set and eliminate tropical water vapor interference to obtain the corrected global water vapor column data set;

[0013] The preliminary identification and regional division unit is used to perform preliminary identification of atmospheric river events from the revised global water vapor column data set. If an atmospheric river event is initially identified, the atmospheric river occurrence area is divided;

[0014] An atmospheric river path extraction unit is used to determine a threshold value using the multi-year interannual water vapor column total distribution in the atmospheric river occurrence area, and extract the atmospheric river path from the atmospheric river occurrence area using the threshold value;

[0015] The secondary identification unit of atmospheric river events is used to calculate the atmospheric river axis using the pixel points corresponding to the highest total water vapor column in the atmospheric river path, and use the atmospheric river axis to determine whether it belongs to a cyclone system; if it belongs to a cyclone system, it indicates that the initially identified atmospheric river event is a misjudgment; if it does not belong to a cyclone system, it indicates that the atmospheric river event is finally identified.

[0016] A processing device, comprising: one or more processors; a memory for storing one or more programs;

[0017] When the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned method.

[0018] A readable storage medium stores a computer program, which implements the above method when the computer program is executed by a processor.

[0019] It can be seen from the technical solution provided by the present invention that the total water vapor column data set obtained by hyperspectral inversion of domestic satellites can be used to automatically identify atmospheric river events. There is no need to perform tedious image refinement processing during the identification process, and interference from other strong water vapor transport events not caused by atmospheric rivers can be filtered out through two identifications, thereby improving the identification accuracy of atmospheric river events. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0021] Figure 1 A flowchart of an atmospheric river identification method based on a domestic hyperspectral satellite provided in an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of an atmospheric river event provided by an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of dividing atmospheric river occurrence areas provided by an embodiment of the present invention;

[0024] Figure 4 A schematic diagram comparing the total amount of water vapor column of a domestic hyperspectral satellite and the total amount of water vapor column of a U.S. hyperspectral satellite provided in an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of calculating the atmospheric river axis provided by an embodiment of the present invention;

[0026] Figure 6 A schematic diagram of an atmospheric river identification system based on a domestically produced hyperspectral satellite provided in an embodiment of the present invention;

[0027] Figure 7 A schematic diagram of a processing device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0029] First, the terms that may be used in this article are explained as follows:

[0030] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0031] The AAAA method provided by the present invention is described in detail below. The contents not described in detail in the embodiments of the present invention belong to the prior art known to professionals in the field. If the specific conditions are not specified in the embodiments of the present invention, the conditions are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments used in the embodiments of the present invention are not specified, they are all conventional products that can be purchased commercially.

[0032] Embodiment 1

[0033] The embodiment of the present invention provides an atmospheric river identification method based on a domestic hyperspectral satellite. Figure 1 As shown, it mainly includes the following steps:

[0034] Step 1: Obtain a global water vapor column data set using domestic satellite hyperspectral inversion, smooth the global water vapor column data set and eliminate tropical water vapor interference to obtain a corrected global water vapor column data set.

[0035] The preferred implementation of this step is as follows:

[0036] (1) Smoothing processing part.

[0037] In the embodiment of the present invention, the global water vapor column data set is processed by interpolation technology to obtain a daily regular grid data set, and then a median filter is used to smooth the daily regular grid data set. Specifically:

[0038] Since the global water vapor column data inverted by domestic hyperspectral satellites are affected by factors such as orbit width, cloud cover, and inversion failure, the values ​​of individual pixels are missing. Therefore, the global water vapor column data are processed by interpolation technology to obtain a daily regular grid data set of 0.25°×0.25°. The life of an atmospheric river is 36 hours. Therefore, the average of the total water vapor column every 2 days is used as input data to make up for the missing pixels caused by the orbit width. Then use a 15×15 median filter to smooth, reduce noise interference in the image, and fill in missing pixels in a small range. To ensure the reliability of the data, large-scale missing pixels are not processed. The specific values ​​involved here are only examples and do not constitute a limitation. In actual applications, users can make corresponding adjustments based on actual conditions or experience.

[0039] (2) Excluding the interference of tropical water vapor.

[0040] In the embodiment of the present invention, the N longitude grid points corresponding to each latitude grid point in the smoothed global water vapor column data set are divided into J groups, each group contains K longitude grid points, and the mean water vapor column value of each group is calculated. It is expressed as:

[0041]

[0042] in, It represents the total amount of water vapor column at the kth longitude grid point in the jth group in the longitude corresponding to the latitude grid point i.

[0043] Exemplarily, the following settings are made: N=1440, J=96, K=15.

[0044] Calculate the mean of the total meridional water vapor column corresponding to the latitude grid point It is expressed as:

[0045]

[0046] If satisfied: and 1≤j≤J, then the latitude grid point i is located in the area affected by tropical water vapor, and the total water vapor column corresponding to the latitude grid point i is deleted; where, Indicates an event The number of times, n represents the set water vapor column total amount threshold, and U represents the set ratio.

[0047] Exemplarily, it is set that: U=2 / 3, n=2.

[0048] Step 2: Perform preliminary identification of atmospheric river events from the revised global water vapor column data set. If it is preliminarily identified as an atmospheric river event, the atmospheric river occurrence area is divided.

[0049] The preferred implementation of this step is as follows:

[0050] (1) Preliminary identification of atmospheric river events.

[0051] Considering that atmospheric rivers in the northern hemisphere ( / southern hemisphere) are generally transmitted along the southwest-northeast ( / northwest-southeast) 45° direction, the directional derivatives perpendicular to the atmospheric river transmission direction are calculated for the total water vapor column in the northern and southern hemispheres in the corrected global water vapor column data set. The directional derivative will change between positive and negative values ​​in the vertical direction. Here, the process of the directional derivative changing to positive and negative values ​​is referred to as positive jump and negative jump, respectively. It is judged whether the directional derivative changes from positive to negative in the vertical direction. If so, it means that the total water vapor column in the vertical direction has a trend of increasing first and then decreasing. The length and width of the area covered by the change of the directional derivative from positive to negative are set to a and b respectively. When a / b>P, it is considered that an atmospheric river event exists, where P represents the set value.

[0052] For example, P is set to 2. The values ​​of a and b are determined according to actual conditions and are not limited here.

[0053] (2) Divide the atmospheric river occurrence area.

[0054] If an atmospheric river event is preliminarily identified, the coordinate (a / 2, b / 2) of the area covered by the first positive jump to the last negative jump is regarded as the center of the atmospheric river occurrence area, and the distance a is expanded from the center to four directions with angles of 0°, 90°, 180° and 270° to the east direction respectively. The area obtained after expansion is the atmospheric river event occurrence area.

[0055] like Figure 2 As shown in the figure, it is a schematic diagram of atmospheric river events; Figure 3 As shown in the figure, it is a schematic diagram of dividing the atmospheric river occurrence area; among them, a and b represent the length and width of the directional derivative jump area respectively, and the square area with a side length of 2a is the divided atmospheric river occurrence area. Figure 2 and Figure 3 In the figure, taking the northern hemisphere as an example, the atmospheric river is transmitted along the southwest-northeast 45° direction, and the directional derivative at an angle of 135° to the east direction (perpendicular to the direction of atmospheric river transmission) changes from positive to negative. Generally, with the atmospheric river axis as the boundary, the right side is positive (corresponding to the white grid line area in the figure) and the left side is negative (corresponding to the white oblique line area in the figure).

[0056] Step 3: Determine a threshold using the multi-year interannual water vapor column distribution in the atmospheric river occurrence area, and use the threshold to extract the atmospheric river path from the atmospheric river occurrence area.

[0057] The preferred implementation of this step is as follows:

[0058] (1) Calculate the first threshold.

[0059] In the atmospheric river occurrence area, the multi-year interannual water vapor column distribution corresponding to the month when the atmospheric river event occurred was counted and sorted from small to large, and the N1% quantile was taken as the first threshold c 1 .

[0060] Exemplarily, it is set that: N1=86.

[0061] Considering that the domestic hyperspectral satellite has a short operating time, the multi-year inter-annual water vapor column data in the embodiment of the present invention can come from foreign hyperspectral satellites. Here, the American hyperspectral satellite is taken as an example. Figure 4 As shown in the figure, the total water vapor column of the domestic hyperspectral satellite is compared with the total water vapor column of the US hyperspectral satellite. The result shows that the correlation R between the two is 0.983. It can be seen that the total water vapor column inverted by the two is significantly correlated. Therefore, the total water vapor column of the US hyperspectral satellite can replace the long-term distribution of the total water vapor column of the domestic hyperspectral satellite. In addition, Figure 4 Here, x and y represent the total water vapor column of the US hyperspectral satellite and the total water vapor column of the domestic hyperspectral satellite, respectively. In y=kx+b, when k=1 and b=0, the two water vapor column data sets are considered to be consistent.

[0062] (2) Calculate the second threshold.

[0063] In the atmospheric river occurrence area, the distribution of the total water vapor column over many years is counted and sorted from small to large, and the N2% quantile is taken as the second threshold c 2 .

[0064] Similarly, the multi-year interannual water vapor column data here come from foreign hyperspectral satellites, such as the US hyperspectral satellite listed above.

[0065] Exemplarily, it is set that: N2=80.

[0066] (3) Extract atmospheric river paths.

[0067] For any pixel point in the atmospheric river occurrence area, take c 1 With c 2 The larger value of is used as the pixel threshold. If the total amount of water vapor column corresponding to the pixel is higher than the threshold, the pixel is retained; otherwise, the pixel is deleted. All pixels in the atmospheric river occurrence area are traversed, and the retained pixels constitute the atmospheric river path.

[0068] In the embodiment of the present invention, the atmospheric river path is a path with a certain width, and only the pixels within the atmospheric river path are retained, and the pixels outside the atmospheric river path are deleted.

[0069] Step 4: Calculate the atmospheric river axis using the pixel points corresponding to the highest total water vapor column in the atmospheric river path, and use the atmospheric river axis to determine whether it belongs to a cyclone system; if it belongs to a cyclone system, it indicates that the initially identified atmospheric river event is a misjudgment; if it does not belong to a cyclone system, it indicates that the atmospheric river event was finally identified.

[0070] The preferred implementation of this step is as follows:

[0071] (1) Calculate the atmospheric river axis.

[0072] Step A: Select the pixel point corresponding to the highest total water vapor column in the atmospheric river path, and record the selected pixel point as point A.

[0073] Step B, select multiple pixel points (for example, 9×9) around point A, obtain multiple pixel points (for example, 15) of the same category as point A through nearest neighbor classification, and obtain a regression line through linear regression, and the stepping direction is indicated by the regression line.

[0074] Step C, in the direction perpendicular to the stepping direction (ab direction), count the line segments composed of pixel points whose total water vapor column amount is greater than ncm, and calculate the centroid of the line segments, which is located on the atmospheric river axis; wherein n represents the set threshold value for the total water vapor column amount, and exemplarily, it is set to: n=2.

[0075] Step D, the centroid moves to the next pixel point (for example, point C and point C') along the stepping direction, the next pixel point is the pixel point that is closest to the centroid by M km in the stepping direction, the next pixel point is taken as point A, and the process returns to step B until the edge of the atmospheric river is reached, all the centroids are connected, and the axis of the atmospheric river is obtained; wherein M is the set distance value, exemplarily, it is set: M = 50.

[0076] In the embodiment of the present invention, the edge of the atmospheric river here refers to the inner and outer boundaries of the atmospheric river path. Assuming that when the current centroid moves to the next pixel point along the stepping direction, there is no pixel point M km away from the nearest pixel point, it can be considered that the current centroid has reached the edge of the atmospheric river.

[0077] like Figure 5 As shown in the figure, the process of calculating the atmospheric river axis is shown. Different grayscales in the figure represent different total water vapor columns. Point A represents the pixel corresponding to the highest total water vapor column in the initial path of the atmospheric river. Represents the stepping direction calculated by the nearest neighbor method, ab, cd, c'd', ef represent the vertical lines in the stepping direction, and D'B-BD-DF represents the calculated atmospheric river axis. The hollow circles other than point A (points C, C', E) represent the pixels in the stepping direction that are 50 km closest to the previous centroid. These pixels are used to determine the position of the vertical line in the stepping direction (such as cd, c'd', ef), and then determine the centroid; the triangle (points B, D, D', F) is the centroid on the vertical line. Points C and D in the figure are at the same position, indicating "stepping direction The pixel point C" which is 50 km closest to the centroid B" and the "centroid D on the vertical line cd determined according to pixel point C" coincide with each other, and the same is true for points E and F. Figure 5 The centroids F and C' continue to move along their respective stepping directions, repeating the steps described above until a certain particle moves to the next pixel point along the stepping direction. If no pixel point about 50 km away is found in the stepping direction, the particle point is taken as the end point of the atmospheric river axis.

[0078] (2) Impact of filtering cyclones.

[0079] Considering that some cyclone systems may be misjudged as atmospheric river events, the atmospheric river axis is used to determine whether it belongs to a cyclone system. Specifically, the atmospheric river axis is evenly divided into multiple parts, and the angle between the end point and the starting point of each part is calculated. If there is an angle greater than 90°, it belongs to a cyclone system, indicating that the initially identified atmospheric river event is a misjudgment and needs to be discarded. Otherwise, it indicates that an atmospheric river event is finally identified.

[0080] After the atmospheric river event is finally identified, the following tasks can be performed:

[0081] (1) Determine the width of the atmospheric river.

[0082] The width of the atmospheric river is calculated by combining the area covered by the atmospheric river path and the length of the atmospheric river axis. The area covered by the atmospheric river path is denoted as S, and the length of the atmospheric river axis is denoted as L. The width of the atmospheric river W = S / L.

[0083] (2) Determine the landing point of the atmospheric river.

[0084] To determine whether an atmospheric river event extends to the land-sea boundary, the atmospheric river path can be overlapped with the global land-sea mask. If there is an intersection, the atmospheric river event is considered to be making landfall, and the intersection is marked as the landfall point.

[0085] Embodiment 2

[0086] The present invention also provides an atmospheric river identification system based on a domestic hyperspectral satellite, which is mainly implemented based on the method provided in the above embodiment, such as Figure 6 As shown, the system mainly includes:

[0087] The data acquisition and correction unit is used to obtain the global water vapor column data set using domestic satellite hyperspectral inversion, smooth the global water vapor column data set and eliminate tropical water vapor interference to obtain the corrected global water vapor column data set;

[0088] The preliminary identification and regional division unit is used to perform preliminary identification of atmospheric river events from the revised global water vapor column data set. If an atmospheric river event is initially identified, the atmospheric river occurrence area is divided;

[0089] An atmospheric river path extraction unit is used to determine a threshold value using the multi-year interannual water vapor column total distribution in the atmospheric river occurrence area, and extract the atmospheric river path from the atmospheric river occurrence area using the threshold value;

[0090] The secondary identification unit of atmospheric river events is used to calculate the atmospheric river axis using the pixel points corresponding to the highest total water vapor column in the atmospheric river path, and use the atmospheric river axis to determine whether it belongs to a cyclone system; if it belongs to a cyclone system, it indicates that the initially identified atmospheric river event is a misjudgment; if it does not belong to a cyclone system, it indicates that the atmospheric river event is finally identified.

[0091] Technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above.

[0092] Embodiment 3

[0093] The present invention also provides a processing device, such as Figure 7 As shown, it mainly includes: one or more processors; a memory for storing one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the methods provided in the aforementioned embodiments.

[0094] Furthermore, the processing device also includes at least one input device and at least one output device; in the processing device, the processor, memory, input device, and output device are connected via a bus.

[0095] In the embodiment of the present invention, the specific types of the memory, input device and output device are not limited; for example:

[0096] The input device may be a touch screen, an image acquisition device, a physical button or a mouse, etc.;

[0097] The output device may be a display terminal;

[0098] The memory may be a random access memory (RAM) or a non-volatile memory, such as a disk memory.

[0099] Embodiment 4

[0100] The present invention also provides a readable storage medium storing a computer program, which implements the method provided in the above embodiment when the computer program is executed by a processor.

[0101] In the embodiment of the present invention, the readable storage medium is a computer-readable storage medium and can be set in the aforementioned processing device, for example, as a memory in the processing device. In addition, the readable storage medium can also be a U disk, a mobile hard disk, a read-only memory (ROM), a disk or an optical disk, etc., which can store program codes.

[0102] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for identifying atmospheric rivers based on domestic hyperspectral satellites, characterized in that: include: Obtain the global water vapor column data set using domestic satellite hyperspectral inversion, smooth the global water vapor column data set and exclude tropical water vapor interference to obtain the corrected global water vapor column data set; The atmospheric river events are preliminarily identified from the revised global water vapor column data set. If they are preliminarily identified as atmospheric river events, the atmospheric river occurrence areas are divided. Determine a threshold value using the multi-year inter-annual water vapor column distribution in the atmospheric river occurrence region, and extract the atmospheric river path from the atmospheric river occurrence region using the threshold value; The atmospheric river axis is calculated using the pixel points corresponding to the highest water vapor column in the atmospheric river path, and the atmospheric river axis is used to determine whether it belongs to a cyclone system; If it belongs to a cyclonic system, it indicates that the atmospheric river event initially identified is a misjudgment; if it does not belong to a cyclonic system, it indicates that the atmospheric river event finally identified is a misjudgment; The preliminary identification of atmospheric river events from the revised global water vapor column total amount data set, if the preliminary identification is an atmospheric river event, then the division of the atmospheric river occurrence area includes: for the total amount of water vapor column in the northern and southern hemispheres in the revised global water vapor column total amount data set, respectively calculating the directional derivatives perpendicular to the atmospheric river transmission direction; judging whether the directional derivative changes from a positive value to a negative value in the vertical direction, if so, it means that the total amount of water vapor column in the vertical direction has a trend of first increasing and then decreasing, and setting the length and width of the area covered by the directional derivative changing from a positive value to a negative value respectively. a, b, when a / b>P, it is considered that an atmospheric river event exists, where P represents the set value; if an atmospheric river event is preliminarily identified, the coordinate (a / 2, b / 2) of the area covered by the first positive jump to the last negative jump is regarded as the center of the atmospheric river occurrence area, and from this center, a distance a is expanded in four directions with angles of 0°, 90°, 180° and 270° to the east direction respectively. The area obtained after expansion is the atmospheric river event occurrence area; where a positive jump means that the directional derivative becomes positive, and a negative jump means that the directional derivative becomes negative; The method of determining a threshold value by using the multi-year water vapor column total amount distribution in the atmospheric river occurrence area and extracting the atmospheric river path from the atmospheric river occurrence area by using the threshold value includes: within the atmospheric river occurrence area, statistically analyzing the multi-year water vapor column total amount distribution in the corresponding month when the atmospheric river event occurs, and sorting them from small to large, taking the N1% quantile as the first threshold value c1; within the atmospheric river occurrence area, statistically analyzing the multi-year water vapor column total amount distribution, and sorting them from small to large, taking the N2% quantile as the second threshold value c2; for any pixel point in the atmospheric river occurrence area, taking the larger value of c1 and c2 as the pixel point threshold, if the water vapor column total amount corresponding to the pixel point is higher than the threshold, the pixel point is retained; otherwise, the pixel point is deleted; traversing all pixel points in the atmospheric river occurrence area, and the atmospheric river path is formed by the retained pixel points; The method of calculating the atmospheric river axis using the pixel points corresponding to the highest water vapor column in the atmospheric river path, and using the atmospheric river axis to determine whether the atmospheric river belongs to a cyclone system includes: Step A, select the pixel point corresponding to the highest total water vapor column in the atmospheric river path, and record the selected pixel point as point A; Step B, select multiple pixel points around point A, obtain multiple pixel points of the same category as point A through nearest neighbor classification, and obtain a regression line through linear regression, and the regression line indicates the stepping direction; Step C: in the direction perpendicular to the stepping direction, count the line segments composed of pixel points whose total water vapor column volume is greater than ncm, and calculate the centroid of the line segments, which is located on the atmospheric river axis; wherein n represents the set water vapor column volume threshold; Step D, the centroid moves to the next pixel point along the stepping direction, the next pixel point is the pixel point that is closest to the centroid in the stepping direction by M km, the next pixel point is taken as point A, and the process returns to step B until the edge of the atmospheric river is reached, all the centroids are connected, and the atmospheric river axis is obtained; wherein M is the set distance value; The atmospheric river axis is divided into multiple parts evenly, and the angle between the end point and the starting point of each part is calculated respectively. If there is an angle greater than 90°, it belongs to a cyclone system, indicating that the initially identified atmospheric river event is a misjudgment.

2. The atmospheric river identification method based on domestic hyperspectral satellite according to claim 1 is characterized in that: The steps of smoothing the global water vapor column data set and eliminating tropical water vapor interference include: Smoothing part: The global water vapor column data set is processed by interpolation technology to obtain a daily regular grid data set, and then the median filter is used to smooth the daily regular grid data set; Excluding tropical water vapor interference: Divide the N longitude grid points corresponding to each latitude grid point in the smoothed global water vapor column data set into J groups, each group contains K longitude grid points, and calculate the mean water vapor column value of each group. It is expressed as: in, It represents the total water vapor column of the kth longitude grid point of the jth group in the longitude corresponding to the latitude grid point i; Calculate the mean of the total meridional water vapor column corresponding to the latitude grid point It is expressed as: If satisfied: and 1≤j≤J means that the latitude grid point i is located in the area affected by tropical water vapor, and the total water vapor column corresponding to the latitude grid point i is deleted; where, Indicates an event The number of times, n represents the set water vapor column total amount threshold, and U represents the set ratio.

3. The atmospheric river identification method based on domestic hyperspectral satellite according to claim 1 is characterized in that: The method also includes: after the atmospheric river event is finally identified, the atmospheric river width is calculated by combining the area covered by the atmospheric river path and the length of the atmospheric river axis, the area covered by the atmospheric river path is recorded as S, and the length of the atmospheric river axis is recorded as L, then the atmospheric river width W = S / L.

4. The atmospheric river identification method based on domestic hyperspectral satellite according to claim 1 is characterized in that: The method also includes: after the atmospheric river event is finally identified, determining the atmospheric river landing point: overlapping the atmospheric river path with the global land and sea mask, if there is an intersection, it is considered that the atmospheric river event is making landfall, and the intersection is marked as the landing point.

5. An atmospheric river identification system based on domestic hyperspectral satellite, characterized in that: The method according to any one of claims 1 to 4 is implemented, and the system comprises: The data acquisition and correction unit is used to obtain the global water vapor column data set using domestic satellite hyperspectral inversion, smooth the global water vapor column data set and eliminate tropical water vapor interference to obtain the corrected global water vapor column data set; The preliminary identification and regional division unit is used to perform preliminary identification of atmospheric river events from the revised global water vapor column data set. If an atmospheric river event is initially identified, the atmospheric river occurrence area is divided; An atmospheric river path extraction unit is used to determine a threshold value using the multi-year interannual water vapor column total distribution in the atmospheric river occurrence area, and extract the atmospheric river path from the atmospheric river occurrence area using the threshold value; The secondary identification unit of atmospheric river events is used to calculate the atmospheric river axis using the pixel points corresponding to the highest total water vapor column in the atmospheric river path, and use the atmospheric river axis to determine whether it belongs to a cyclone system; if it belongs to a cyclone system, it indicates that the initially identified atmospheric river event is a misjudgment; if it does not belong to a cyclone system, it indicates that the atmospheric river event is finally identified.

6. A processing device, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 4.

7. A readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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