A typhoon center positioning method and system based on water vapor flux vortex characteristics

Abstract

The application belongs to the technical field of meteorology, and discloses a center positioning method and system based on typhoon water vapor flux vortex characteristics. First, the typhoon circulation field is calculated according to the isohypse surface echo data of adjacent time through the CLTREC method, and the typhoon water vapor flux is calculated in combination with the reflectivity estimation rain intensity. Then, the position most similar to the water vapor flux characteristics within the limited range of the past reference center is found as the initial typhoon estimation center of the current time through the iterative method. Finally, the optimal estimation center of the typhoon of the current time is determined by searching the maximum vortex characteristics. The application can better adaptively identify the offshore typhoon center positioning of different scales and different shape structures, thereby comprehensively improving the typhoon center positioning accuracy and stability and other problems of the typhoon meteorological service in China, and providing more scientific technical support for the typhoon subjective positioning.

Description

Technical Field

[0001] This invention belongs to the field of meteorological technology, and in particular relates to a center positioning method and system based on the vortex characteristics of typhoon water vapor flux. Background Technology

[0002] Precise location of the tropical cyclone center is crucial for improving typhoon track forecasting and short-term typhoon storm forecasting. Furthermore, its precise location is also a key parameter for estimating tropical meteorological intensity. For typhoons with eyes, the asymmetry and non-circular structure of the typhoon center present a significant challenge. Current methods for typhoon center location primarily rely on GPS, radiosonde, satellite remote sensing, and Doppler radar observations. At sea, satellite cloud imagery is the main method for typhoon center location. However, when a typhoon is near the coast, the influence of island and continental topography enhances the asymmetry of the typhoon eye, making its structure more complex. Satellites, due to their relatively low resolution, struggle to accurately determine the typhoon center's location. In such cases, high spatiotemporal resolution radar observations become the most effective tool for typhoon center location.

[0003] Although there are many radar data-based positioning methods (GBVTD-simplex method, TCET method, TECT method, etc.), they are prone to positioning failure when the typhoon eye structure is complex (eyewall too narrow; typhoon eye too large; poor shape symmetry and closure, etc.) or when the typhoon eye structure changes too rapidly.

[0004] Based on the above analysis, the problems and shortcomings of the existing technology are as follows:

[0005] 1) For typhoon eye structures that are complex (eyewall too narrow; typhoon eye too large; poor shape symmetry and closure, etc.) and typhoon eye structures that change too rapidly, subjective positioning is inherently very difficult, and existing objective positioning techniques are generally ineffective in such cases.

[0006] 2) For problems with uncertain feature information, how to perform mathematical modeling and then scientifically describe the problem is a challenge.

[0007] 3) The biggest challenge of this invention is how to integrate existing scientific knowledge about typhoons into the algorithm model so that the positioning is closer to subjective positioning. Summary of the Invention

[0008] To address the problems existing in the prior art, this invention provides a center positioning method and system based on the vortex characteristics of typhoon water vapor flux. First, the typhoon circulation field is calculated using the CLTREC method (Huang et al., 2017) based on isotope echo data from adjacent time periods. Then, the typhoon water vapor flux is calculated by estimating rainfall intensity using reflectivity. Next, an iterative method is used to find the location most similar to the water vapor flux characteristics within a limited range of the past reference center, which is then used as the initial typhoon estimation center for the current time period. Finally, the optimal estimation center location for the typhoon at the current time period is determined by searching for the location with the largest vortex characteristic.

[0009] This invention is implemented as follows: a center localization method based on the vortex characteristics of typhoon water vapor flux, comprising:

[0010] S1. The typhoon circulation field is calculated using the CLTREC method based on radar contour echo data from adjacent time periods. Then, the gridded radar echo is converted into gridded hourly rainfall intensity using the ZR relationship between typhoon warm and rain. Finally, the gridded wind speed retrieved by the CLTREC method is multiplied by the gridded rainfall intensity to obtain the typhoon wind point water vapor flux data MF.

[0011] S2. Based on the typhoon center locations of past times and combined with the typhoon movement information predicted in the reports, the search interval for the typhoon center of the current time is determined. Then, the location of the maximum correlation coefficient of water vapor flux characteristics is found through iterative search within this interval. Finally, the initial guessed center of the typhoon of the current time is determined.

[0012] S3. Using the estimated initial typhoon center as the center position, search for the maximum vortex feature within the typhoon eye radius RA. After determining the maximum vortex feature value, use the maximum vortex feature value * 0.95 as the significant vortex feature threshold. Finally, use the average position of all areas above the threshold as the typhoon center.

[0013] Furthermore, S2 determines the typhoon center search interval for the current time period specifically as follows: the typhoon center position of the past time period is used as the starting position A of the interval, the typhoon position predicted in the typhoon report for the current time period is used as the middle position B of the interval, and the typhoon position calculated by combining the predicted typhoon movement direction in the typhoon report with the historical maximum typhoon movement speed is used as the ending position C of the interval. That is, position C is equal to position A plus the predicted typhoon movement direction in the report multiplied by the historical maximum typhoon movement speed.

[0014] Furthermore, the calculation of the correlation coefficient of water vapor flux characteristics within a limited range in S2 specifically includes: calculating the correlation coefficient C of water vapor flux characteristics for the test locations within the search interval according to formula (1-6):

[0015] C = (F U +F V +F MP +FR ) / 4 (1)

[0016] in,

[0017]

[0018]

[0019]

[0020]

[0021]

[0022] The weighting coefficient W relative to the typhoon center is determined by the distance D from the grid point to the typhoon center. C and statistical radius D S RA is the typhoon eye radius, calculated according to formula (6) (this information is determined manually by the forecaster from the report or at the initial moment); formula (2) is used to calculate the similarity of the U component features F. U The formula is as follows: U represents the x-direction component of the wind speed inverted by the CLTREC method in the Cartesian coordinate system multiplied by the distance weighting coefficient W relative to the typhoon center; U1 represents the current time; U2 represents the data corresponding to the past time; Formula (3) is used to calculate the similarity F of the V component features. V The formula (4) is used to calculate the similarity F of the typhoon center water vapor flux data MF in the Cartesian coordinate system obtained by the CLTREC method. V represents the y-direction component of the wind speed inverted by the CLTREC method multiplied by the distance weighting coefficient W relative to the typhoon center. V1 represents the current time and V2 represents the data corresponding to the past time. MF The formula is as follows: MP represents the typhoon point water vapor flux data MF multiplied by the distance weighting coefficient W relative to the typhoon center; MP1 represents the current time; MP2 represents the data corresponding to the past time; Formula (5) is the similarity F of radar combined reflectivity data features. R The formula is as follows: R represents the radar combined reflectivity data multiplied by the distance weighting coefficient W relative to the typhoon center, R1 represents the current time, and R2 represents the data corresponding to the past time.

[0023] Furthermore, the search for the location with the maximum correlation coefficient of water vapor flux characteristics in S2 specifically involves iteratively adjusting the positions at the determined search locations A, B, and C according to the following rules, and finally finding the location with the maximum correlation coefficient of water vapor flux characteristics, which is the estimated initial typhoon center location:

[0024] 1) Calculate the correlation coefficient C of water vapor flux characteristics within a limited range of locations A, B, and C;

[0025] 2) If the positional difference between A, B, and C is less than the distance threshold, then exit the loop;

[0026] 3) Analyze the correlation coefficient C of water vapor flux characteristics over a limited range of locations A, B, and C:

[0027] If the maximum correlation coefficient is at position A, then the new position of A remains unchanged, and the new position of B is adjusted to be the average of positions A and B, and the new position of C is adjusted to be position B;

[0028] If the maximum correlation coefficient is at position B, then the new position of B remains unchanged, and the new position of A is adjusted to be the average of positions A and B, and the new position of C is adjusted to be the average of positions B and C.

[0029] If the maximum correlation coefficient is at position C, then the new position of C remains unchanged, and the new position of B is adjusted to be the average of positions C and B, and the new position of A is adjusted to position B.

[0030] 4) Continue with step 1).

[0031] Furthermore, the calculation formula in S3 is as follows:

[0032]

[0033] in

[0034] W is the distance weighting coefficient relative to the typhoon center, calculated using Formula 7. The vortex characteristic is calculated by traversing the statistical radius around the test point, calculating the cumulative wind direction difference S at each position (1 degree angle, 5 km radial distance). When the wind direction DI retrieved by CLTREC is... cltrec And the corresponding wind shear DI centered on the test point t The absolute value of the wind direction angle difference is less than the threshold T d If the default is 75 degrees, then calculate according to formula 7; otherwise, the result is 0.

[0035] Another object of the present invention is to provide a center positioning system based on typhoon water vapor flux vortex characteristics, which applies the aforementioned center positioning method based on typhoon water vapor flux vortex characteristics, comprising:

[0036] The typhoon water vapor flux calculation module is used to calculate the typhoon circulation field based on radar contour echo data from adjacent time periods using the CLTREC method; then, using the ZR relationship between typhoon warm and rain, the gridded radar echo is converted into gridded hourly rainfall intensity; finally, the gridded wind speed retrieved by the CLTREC method is multiplied by the gridded rainfall intensity to obtain the typhoon wind point water vapor flux data MF.

[0037] The typhoon center estimation module is used to determine the typhoon center search range for the current time by combining the typhoon center positions of past times with the typhoon movement information predicted in the reports. Then, it finds the position of the maximum correlation coefficient of water vapor flux characteristics in this range through iterative search, and finally determines the initial guessed center of the typhoon for the current time.

[0038] The optimal typhoon center search module uses the estimated initial typhoon center as the center position and searches for the maximum vortex feature within the typhoon eye radius RA. After determining the maximum vortex feature value, the maximum vortex feature value * 0.95 is determined as the significant vortex feature threshold. Finally, the average position of all regions above the threshold is taken as the typhoon center.

[0039] Another object of the present invention is to provide a computer device, the computer device including a memory and a processor, the memory storing a computer program, and when the computer program is executed by the processor, causing the processor to perform the steps of the center positioning method based on the vortex characteristics of typhoon water vapor flux.

[0040] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the center positioning method based on the vortex characteristics of typhoon water vapor flux.

[0041] Another objective of this invention is to provide an information data processing terminal for implementing the aforementioned center positioning system based on the vortex characteristics of typhoon water vapor flux.

[0042] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0043] First, regarding the technical problems existing in the aforementioned prior art and the difficulty of solving these problems, the creative technical effects that arise after solving the problems are described in detail below:

[0044] This invention fully considers the current status of typhoon operations in China (business needs, data quality, etc.), and utilizes extensive computer image recognition and parallel optimization technologies to achieve real-time typhoon center positioning. It can perform automatic single-radar monitoring and center positioning of various types of typhoons (different intensities and eye structures) within the effective coverage area of ​​China's networked radar. Typhoon positioning accuracy evaluation results show that regardless of whether the typhoon eye is clear or the structure is symmetrical, as long as there are certain curvature characteristics in the retrieved circulation, the improved typhoon system can continuously track and locate the centers of typhoons of different intensities.

[0045] Secondly, this invention can better adaptively identify the center location of nearshore typhoons of different scales and shapes, thereby comprehensively improving the accuracy and stability of typhoon center positioning in China's typhoon meteorological services and providing more scientific technical support for subjective typhoon positioning.

[0046] Improved positioning accuracy: By comprehensively using multi-source data and advanced algorithms, the positioning accuracy of the typhoon center has been significantly improved.

[0047] Enhanced real-time dynamic tracking capabilities: Through iterative search and vortex feature analysis, the dynamic changes of the typhoon center can be tracked more quickly and accurately.

[0048] Promoting disaster prevention and mitigation: Accurate typhoon center location helps in early warning and reduces losses caused by natural disasters, which is of great significance for public safety and disaster response.

[0049] Third, the expected benefits and commercial value of the technical solution of this invention after transformation are as follows: This invention can comprehensively improve the accuracy and stability of typhoon center positioning in China's typhoon meteorological services, provide more scientific technical support for subjective typhoon positioning, and greatly enhance the intelligent operation level of typhoon meteorological services.

[0050] The technical solution of this invention fills a technological gap in the industry both domestically and internationally: For typhoon eye structures that are complex (eyewalls too narrow; eye too large; poor shape symmetry and closure, etc.) and where the typhoon eye structure changes too rapidly, subjective positioning is inherently very difficult, and existing objective positioning technologies are generally ineffective in such cases. This invention, for the first time in China, provides a relatively scientific solution to the above-mentioned difficulties from a technical perspective and has been successfully implemented in practice.

[0051] The technical solution of this invention solves a long-standing but unresolved technical problem: subjective positioning is inherently difficult when the typhoon eye structure is complex (too narrow an eyewall; too large an eye; poor shape symmetry and closure, etc.) or when the typhoon eye structure changes too rapidly. Existing objective positioning technologies are generally ineffective in such cases. This invention can achieve better adaptive identification and positioning of nearshore typhoon centers of different scales and shapes, thereby comprehensively improving the accuracy and stability of typhoon center positioning in China's typhoon meteorological operations, and providing more scientific technical support for subjective typhoon positioning. Attached Figure Description

[0052] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a flowchart of the center positioning method based on the vortex characteristics of typhoon water vapor flux provided in the embodiments of the present invention;

[0054] Figure 2 This is a structural diagram of the center positioning system based on the vortex characteristics of typhoon water vapor flux provided in an embodiment of the present invention;

[0055] Figure 3 This is a superimposed echo of the typhoon path and a typhoon inversion wind field map provided in an embodiment of the present invention (Zhanjiang Radar LTC202307171400);

[0056] Figure 4 This is a superimposed echo of the typhoon path and a typhoon inversion wind field map provided in an embodiment of the present invention (Zhanjiang Radar LTC202307180601);

[0057] Figure 5 This is a time-series diagram of the positioning error (km) of Typhoon Talim (Zhanjiang radar) provided in an embodiment of the present invention;

[0058] Figure 6 This is a superimposed echo of the typhoon path and a typhoon inversion wind field map provided in an embodiment of the present invention (Xiamen Radar LTC202307272200);

[0059] Figure 7 This is a superimposed echo of the typhoon path and a typhoon inversion wind field map provided in an embodiment of the present invention (Xiamen Radar LTC202307281056);

[0060] Figure 8 This is a time-series diagram of the positioning error (km) of Typhoon Doksuri (Xiamen radar) provided in an embodiment of the present invention;

[0061] Figure 9 This is a superimposed echo of the typhoon path and a typhoon inversion wind field map provided in an embodiment of the present invention (Shenzhen Radar LTC202309011001);

[0062] Figure 10 This is a superimposed echo of the typhoon path and a typhoon inversion wind field map provided in an embodiment of the present invention (Shenzhen Radar LTC202309020501);

[0063] Figure 11 This is a time-series diagram of the positioning error (km) of Typhoon Saola (Shenzhen radar) provided in an embodiment of the present invention;

[0064] Figure 12 This is a superimposed echo of the typhoon path and a typhoon inversion wind field map provided in an embodiment of the present invention (Shantou Radar LTC202309041601);

[0065] Figure 13 This is a superimposed echo of the typhoon path and a typhoon inversion wind field map provided in an embodiment of the present invention (Shantou Radar LTC202309050001);

[0066] Figure 14 This is a time-series diagram of the positioning error (km) of Typhoon Haikui (Shantou radar) provided in an embodiment of the present invention. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0068] This invention addresses the following problems and deficiencies in the prior art, achieving significant technological advancements:

[0069] Insufficient positioning accuracy: Traditional typhoon center positioning methods rely on satellite and radar data, but these methods have low positioning accuracy when cloud cover is dense or data is insufficient.

[0070] Low data utilization efficiency: Existing technologies fail to fully utilize multi-source data (such as radar, satellite, wind speed, etc.) for comprehensive analysis, resulting in inaccurate typhoon path prediction and tracking.

[0071] Weak dynamic tracking capability: Traditional methods often fail to respond promptly when dealing with rapidly changing meteorological conditions, such as the rapid movement and intensity changes of typhoons, making it difficult to achieve real-time dynamic tracking.

[0072] To address the problems existing in the prior art, the technical solution adopted in this invention is as follows:

[0073] Comprehensive multi-source data analysis: The typhoon circulation field is calculated by combining radar contour echo data with the CLTREC method, and the rainfall intensity is estimated by comprehensively considering reflectivity to calculate the typhoon water vapor flux, thereby improving the efficiency of data utilization.

[0074] Iterative search for the initial estimation center: By using an iterative method, the location with the most similar water vapor flux characteristics within a limited range is found as the initial typhoon estimation center for the current time period, thereby improving the initial accuracy of the positioning.

[0075] Vortex feature maximization search: Based on the estimated initial typhoon center, search for the location with the largest vortex feature to determine the optimal estimated center and further improve positioning accuracy.

[0076] To address the problems existing in the prior art, this invention provides a center positioning method and system based on the vortex characteristics of typhoon water vapor flux. The invention will be described in detail below with reference to the accompanying drawings.

[0077] Two specific application embodiments of the present invention are as follows:

[0078] Example 1: Rapid Typhoon Path Forecast

[0079] Data collection: First, collect radar contour data and other relevant meteorological data for specific typhoons.

[0080] Circulation field calculation: The collected radar data was processed using the CLTREC method to calculate the typhoon circulation field.

[0081] Water vapor flux estimation: Combine reflectivity data to estimate rainfall intensity, and then combine it with calculated wind speed data to estimate water vapor flux at each grid point of the typhoon.

[0082] Initial estimation center location: Using an iterative search method, the location with the most similar water vapor flux characteristics within the predicted typhoon movement path is found and used as the initial estimation center of the typhoon.

[0083] Determining the optimal estimation center: Using the initial estimation center as the base point, search for the region with the strongest vortex characteristics and locate it as the optimal estimation center.

[0084] Example 2: Real-time monitoring of typhoon intensity

[0085] Real-time data analysis: Real-time collection of radar contour data and other meteorological parameters during typhoons.

[0086] Typhoon characteristic analysis: The CLTREC method was used to analyze the typhoon circulation field, and the water vapor flux was calculated in combination with rainfall intensity data.

[0087] Dynamic center tracking: Based on the data of each time period, iteratively search for the initial typhoon estimation center for the current time period.

[0088] Vortex feature assessment: Identify the region with the most obvious vortex features around the estimation center, and then determine the optimal estimation center.

[0089] Intensity change monitoring: The intensity change of the typhoon is assessed by continuously monitoring the vortex characteristics.

[0090] like Figure 1 As shown, the center localization method based on the vortex characteristics of typhoon water vapor flux provided in this embodiment of the invention includes:

[0091] S1. The typhoon circulation field is calculated using the CLTREC method based on radar contour echo data from adjacent time periods. Then, the gridded radar echo is converted into gridded hourly rainfall intensity using the ZR relationship between typhoon warm and rain. Finally, the gridded wind speed retrieved by the CLTREC method is multiplied by the gridded rainfall intensity to obtain the typhoon wind point water vapor flux data MF.

[0092] S2. Based on the typhoon center locations of past times and combined with the typhoon movement information predicted in the reports, the search interval for the typhoon center of the current time is determined. Then, the location of the maximum correlation coefficient of water vapor flux characteristics is found through iterative search within this interval. Finally, the initial guessed center of the typhoon of the current time is determined.

[0093] S3. Using the estimated initial typhoon center as the center position, search for the maximum vortex feature within the typhoon eye radius RA. After determining the maximum vortex feature value, use the maximum vortex feature value * 0.95 as the significant vortex feature threshold. Finally, use the average position of all areas above the threshold as the typhoon center.

[0094] like Figure 2 As shown, the center positioning system based on the vortex characteristics of typhoon water vapor flux provided in this embodiment of the invention includes:

[0095] The typhoon water vapor flux calculation module is used to calculate the typhoon circulation field based on radar contour echo data from adjacent time periods using the CLTREC method; then, using the ZR relationship between typhoon warm and rain, the gridded radar echo is converted into gridded hourly rainfall intensity; finally, the gridded wind speed retrieved by the CLTREC method is multiplied by the gridded rainfall intensity to obtain the typhoon wind point water vapor flux data MF.

[0096] The typhoon center estimation module is used to determine the typhoon center search range for the current time by combining the typhoon center positions of past times with the typhoon movement information predicted in the reports. Then, it finds the position of the maximum correlation coefficient of water vapor flux characteristics in this range through iterative search, and finally determines the initial guessed center of the typhoon for the current time.

[0097] The optimal typhoon center search module uses the estimated initial typhoon center as the center position and searches for the maximum vortex feature within the typhoon eye radius RA. After determining the maximum vortex feature value, the maximum vortex feature value * 0.95 is determined as the significant vortex feature threshold. Finally, the average position of all regions above the threshold is taken as the typhoon center.

[0098] 1. Technical methods

[0099] The center localization method based on the vortex characteristics of typhoon water vapor flux first calculates the typhoon circulation field using the CLTREC method based on the contour echo data of adjacent time periods, and calculates the typhoon water vapor flux by estimating rainfall intensity using reflectivity. Then, iteratively, it finds the location with the most similar water vapor flux characteristics within a limited range of the past reference center as the initial typhoon estimation center for the current time period. Finally, it determines the optimal estimation center of the typhoon for the current time period by searching for the maximum vortex characteristic.

[0100] 1.1 Calculate the typhoon water vapor flux

[0101] The typhoon circulation field was calculated using the CLTREC method (Huang et al., 2017) based on radar contour echo data from adjacent time periods. Then, the gridded radar echoes were converted into gridded hourly rainfall intensities using the ZR relationship between typhoon warm and rainy weather. Finally, the gridded wind speeds retrieved by the CLTREC method were multiplied by the gridded rainfall intensities to obtain the typhoon wind point water vapor flux data (MF).

[0102] 1.2 Initial Typhoon Center Estimation Method

[0103] By combining the typhoon center locations from past time periods with the typhoon movement information predicted in the reports, the search range for the typhoon center in the current time period is determined. Then, within this range, the location with the maximum correlation coefficient of water vapor flux characteristics is found through iterative search. Finally, the initial guessed center of the typhoon in the current time period is determined.

[0104] 1.2.1 Determine the search range for the typhoon center at the current time.

[0105] The starting position A of the interval is the typhoon center position in the past time period. The middle position B of the interval is the typhoon position predicted in the typhoon report for the current time period. The ending position C of the interval is the typhoon position calculated by combining the typhoon movement direction predicted in the typhoon report with the maximum typhoon movement speed in the same historical period (that is, position C equals position A plus the typhoon movement direction predicted in the report multiplied by the maximum typhoon movement speed in the same historical period).

[0106] 1.2.2 Calculate the correlation coefficient of water vapor flux characteristics within a limited range

[0107] The correlation coefficient C of water vapor flux characteristics is calculated for the test locations within the search interval according to formula (1-6):

[0108] C = (F U +F V +F MP +F R ) / 4 (1)

[0109] in,

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] Here, the weighting coefficient W relative to the typhoon center is determined by the distance D from the grid point to the typhoon center. C and statistical radius D SThe radius of the typhoon eye is calculated according to formula (6), where RA is the radius of the typhoon eye (this information is determined manually by the forecaster from the report or at the initial moment). Formula (2) is used to calculate the similarity F of the U component features. U The formula is as follows: U represents the x-direction component of the wind speed retrieved by the CLTREC method in the Cartesian coordinate system multiplied by the distance weighting coefficient W relative to the typhoon center; U1 represents the current time period; and U2 represents the corresponding data for past time periods. Formula (3) is used to calculate the similarity F of the V component characteristics. V The formula (4) is used to calculate the similarity F of the typhoon center water vapor flux data MF in the Cartesian coordinate system obtained by the CLTREC method. V represents the y-direction component of the wind speed inverted by the CLTREC method multiplied by the distance weighting coefficient W relative to the typhoon center. V1 represents the current time and V2 represents the data corresponding to the past time. MF The formula is as follows: MP represents the typhoon point water vapor flux data MF multiplied by the distance weighting coefficient W relative to the typhoon center, MP1 represents the current time, and MP2 represents the data corresponding to the past time. Formula (5) is the similarity F of radar combined reflectivity data features. R The formula is as follows: R represents the radar combined reflectivity data multiplied by the distance weighting coefficient W relative to the typhoon center, R1 represents the current time, and R2 represents the data corresponding to the past time.

[0116] 1.2.3 Searching for the location with the highest correlation coefficient of water vapor flux characteristics

[0117] The search locations A, B, and C, as determined in section 2.2.1, are iteratively adjusted according to the following rules. Finally, the location with the highest correlation coefficient of water vapor flux characteristics is found, which is the estimated initial typhoon center location:

[0118] 1) Calculate the correlation coefficient C of water vapor flux characteristics within a finite range of locations A, B, and C.

[0119] 2) If the positional difference between A, B, and C is less than the distance threshold, then exit the loop.

[0120] 3) Analyze the correlation coefficient C of water vapor flux characteristics over a limited range of locations A, B, and C:

[0121] If the maximum correlation coefficient is at position A, then the new position of A remains unchanged, and the new position of B is adjusted to be the average of positions A and B, and the new position of C is adjusted to be position B.

[0122] If the maximum correlation coefficient is at position B, then the new position of B remains unchanged, and the new position of A is adjusted to be the average of positions A and B, and the new position of C is adjusted to be the average of positions B and C.

[0123] If the maximum correlation coefficient is at position C, then the new position of C remains unchanged, and the new position of B is adjusted to be the average of positions C and B, while the new position of A is adjusted to position B.

[0124] 4) Continue with step 1).

[0125] 1.4 Optimal Typhoon Center Search Method

[0126] Using the estimated initial typhoon center as the center location, a search for the maximum vortex feature is performed within the typhoon eye radius RA. After determining the maximum vortex feature value, the threshold for significant vorticity feature is determined by multiplying the maximum vortex feature value by 0.95. Finally, the average position of all regions above the threshold is taken as the typhoon center.

[0127]

[0128] in

[0129]

[0130] W is the distance weighting coefficient relative to the typhoon center, calculated using Formula 7. The vortex characteristic is calculated by traversing the statistical radius from the test point, calculating the cumulative wind direction difference S at each position (1 degree angle, 5 km radial distance). When the wind direction DI retrieved by CLTREC... cltrec And the corresponding wind shear DI centered on the test point t The absolute value of the wind direction angle difference is less than the threshold T d If the default is 75 degrees, then calculate according to formula 7; otherwise, the result is 0.

[0131] 2. Inspection and evaluation

[0132] 2.1 Typhoon Talim (2304)

[0133] This typhoon had a relatively long lifespan and a large eye before landfall; however, after landfall, the eye gradually shrank, and its structure exhibited significant asymmetry. The typhoon's process (Beijing time 2023071709-2023071811) was assessed using the Zhanjiang radar. (Typhoon system location deviation time series diagram) Figure 5 This indicates that although typhoons have long lifespans and undergo significant changes in their eye structure, the typhoon system can still stably and continuously track and locate their centers. The minimum positioning error between this tracking and the subjective positioning provided by the reports is generally within the range of 5-20 km. Of course, the issue of larger positioning errors at certain times requires further in-depth research. (Single radar typhoon positioning and typhoon wind field maps at different times are shown.) Figures 3-4The results show that the typhoon system can be well located, whether it is the initial large eye structure or the less clear typhoon eye after landfall. The inverted typhoon wind field reveals the distribution characteristics of the typhoon cyclonic circulation wind field during the landfall process.

[0134] 2.2 Typhoon Doksuri (2305)

[0135] The typhoon initially possessed a two-eyed structure; as it approached landfall, the inner and outer eyes gradually merged, and finally, after landfall, the typhoon's eye gradually shrank, exhibiting a certain degree of asymmetry in its eye structure. The typhoon's process (Beijing time 2023072722-2023072811) was assessed using the Xiamen radar. A time series diagram of the typhoon system's location deviation is shown. Figure 8 This indicates that although the typhoon eye structure underwent complex changes throughout the landfall process, the typhoon system could still stably and continuously track and locate the typhoon's center. The minimum positioning error range between this and the subjective positioning via reports was generally between 5-15 km. (Single radar typhoon positioning and typhoon wind field maps at different times are shown.) Figures 6-7 The results show that the typhoon system can be well located, whether it is the initial double-eye structure or the asymmetric typhoon eye after the double-eye merger. The inverted typhoon wind field reveals the distribution characteristics of the typhoon cyclonic circulation wind field.

[0136] 2.3 Typhoon Saola (2309)

[0137] The typhoon's eye is asymmetrical and non-closed; initially, Shenzhen radar could only observe partial typhoon information. As it approached landfall, the eye's structural features gradually became blurred. The typhoon's process (Beijing time 2023090109-2023090213) was assessed using Shenzhen radar. A time series diagram of the typhoon system's positioning deviation is shown. Figure 11 This indicates that the typhoon system can reliably and continuously track and locate the center of typhoons with unclear eye characteristics, with the minimum positioning error range between the radar and the subjective positioning via reports generally between 5-15 km. Of course, the issue of larger positioning errors at certain times requires further in-depth research. (Single radar typhoon positioning and typhoon wind field maps at different times are shown.) Figures 9-10 This indicates that typhoon systems can continuously track and locate the eye of such typhoons, and the inverted typhoon wind field reveals the distribution characteristics of the cyclonic circulation wind field of typhoons.

[0138] 2.4 Typhoon Haikui (2311)

[0139] This typhoon exhibits highly asymmetrical, loosely structured, and non-closed typhoon eye characteristics. The typhoon's process (Beijing time 2023090412-2023090508) was assessed using the Shantou radar. A time series diagram of the typhoon system's location deviation is provided. Figure 14 This indicates that the typhoon system can still reliably and continuously track and locate the center of typhoons with unclear eye characteristics, although the minimum positioning error range is slightly larger than that of the previous three typhoons and the subjective positioning via reports (errors of 5-15 km in some periods, and 20-30 km in many others). Therefore, the eye positioning technology for this type of typhoon still needs further improvement. In addition, single-radar typhoon positioning and typhoon wind field maps at different times (…) Figures 12-13 This indicates that the typhoon wind field retrieved by the typhoon system generally reveals the distribution and evolution characteristics of the cyclonic circulation wind field during the typhoon's landfall process relatively well, and it still has some reference value for forecasting.

[0140] An application embodiment of the present invention provides a computer device, which includes a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the processor performs the steps of a center positioning method based on the characteristics of typhoon water vapor flux vortex.

[0141] An application embodiment of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of a center localization method based on the vortex characteristics of typhoon water vapor flux.

[0142] An application embodiment of the present invention provides an information data processing terminal, which is used to realize a center positioning system based on the vortex characteristics of typhoon water vapor flux.

[0143] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or by software executed by various types of processors, or by a combination of the above-described hardware circuitry and software, such as firmware.

[0144] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A center localization method based on the vortex characteristics of typhoon water vapor flux, characterized in that, include: First, the typhoon circulation field is calculated using the CLTREC method based on the contour echo data of adjacent time periods, and the typhoon water vapor flux is calculated by estimating the rainfall intensity in combination with reflectivity. Then, the location with the most similar water vapor flux characteristics within a limited range of the past reference center is found by iterative method as the initial typhoon estimation center for the current time period. Finally, the optimal estimation center location of the typhoon for the current time period is determined by searching for the maximum vortex characteristics. The steps of the center localization method based on the vortex characteristics of typhoon water vapor flux are as follows: S1. The typhoon circulation field is calculated using the CLTREC method based on radar contour echo data from adjacent time periods. Then, the gridded radar echo is converted into gridded hourly rainfall intensity using the ZR relationship between typhoon warm and rain. Finally, the gridded wind speed retrieved by the CLTREC method is multiplied by the gridded rainfall intensity to obtain the typhoon wind point water vapor flux data MF. S2. Based on the typhoon center locations of past times and combined with the typhoon movement information predicted in the reports, the search interval for the typhoon center of the current time is determined. Then, the location of the maximum correlation coefficient of water vapor flux characteristics is found through iterative search within this interval. Finally, the initial guessed center of the typhoon of the current time is determined. S3. Using the estimated initial typhoon center as the center position, search for the maximum vortex feature within the typhoon eye radius RA. After determining the maximum vortex feature value, use the maximum vortex feature value * 0.95 as the significant vortex feature threshold. Finally, use the average position of all areas above the threshold as the typhoon center.

2. The center localization method based on typhoon water vapor flux vortex characteristics as described in claim 1, characterized in that, S2 determines the search interval for the typhoon center at the current time by: using the typhoon center position of a past time as the starting position A of the interval, using the typhoon position predicted in the typhoon report for the current time as the middle position B of the interval, and using the typhoon position calculated by combining the predicted typhoon movement direction in the typhoon report with the historical maximum typhoon movement speed as the ending position C of the interval. That is, position C is equal to position A plus the predicted typhoon movement direction in the report multiplied by the historical maximum typhoon movement speed.

3. The center localization method based on the vortex characteristics of typhoon water vapor flux as described in claim 1, characterized in that... The calculation of the correlation coefficient of water vapor flux characteristics within a limited range in S2 specifically includes: calculating the correlation coefficient C of water vapor flux characteristics for the test locations within the search interval according to formula (1-6): （1） in, （2） （3） （4） （5） （6） The weighting coefficient W relative to the typhoon center is determined by the distance from the grid point to the typhoon center. and statistical radius RA is the radius of the typhoon eye, calculated according to formula (6); formula (2) is used to calculate the similarity of the U component features. The formula is given, where U represents the x-component of the wind speed retrieved by the CLTREC method in Cartesian coordinates multiplied by the distance weighting coefficient W relative to the typhoon center. Indicates the current time. This represents the corresponding data in the past; Formula (3) is used to calculate the similarity of V component features. The formula, V represents the y-component of the wind speed inverted by the CLTREC method in the Cartesian coordinate system multiplied by the distance weighting coefficient W relative to the typhoon center. Indicates the current time. This represents the corresponding data in the past; Formula (4) is used to calculate the similarity of MF features of the water vapor flux data at the wind point of the station. The formula, MP, represents the typhoon point water vapor flux data MF multiplied by the distance weighting coefficient W relative to the typhoon center. Indicates the current time. This represents the corresponding data from the past; Formula (5) represents the similarity of radar combined reflectivity data features. The formula, R, represents the radar combined reflectivity data multiplied by the distance weighting coefficient W relative to the typhoon center. Indicates the current time. This indicates data corresponding to past tense times.

4. The center localization method based on the vortex characteristics of typhoon water vapor flux as described in claim 2, characterized in that, The search for the location with the maximum correlation coefficient of water vapor flux characteristics in S2 specifically involves iteratively adjusting the search positions A, B, and C according to the following rules. Finally, the location with the maximum correlation coefficient of water vapor flux characteristics is found, which is the estimated initial typhoon center location. 1) Calculate the correlation coefficient C of water vapor flux characteristics within a limited range of locations A, B, and C; 2) If the positional difference between A, B, and C is less than the distance threshold, then exit the loop; 3) Analyze the correlation coefficient C of water vapor flux characteristics over a limited range of locations A, B, and C: If the maximum correlation coefficient is at position A, then the new position of A remains unchanged, and the new position of B is adjusted to be the average of positions A and B, and the new position of C is adjusted to be position B; If the maximum correlation coefficient is at position B, then the new position of B remains unchanged, and the new position of A is adjusted to be the average of positions A and B, and the new position of C is adjusted to be the average of positions B and C. If the maximum correlation coefficient is at position C, then the new position of C remains unchanged, and the new position of B is adjusted to be the average of positions C and B, and the new position of A is adjusted to position B. 4) Continue with step 1).

5. The center localization method based on the vortex characteristics of typhoon water vapor flux as described in claim 1, characterized in that, The calculation formula in S3 is: ， in, (7) W is the distance weighting coefficient relative to the typhoon center. The vortex characteristic is calculated by traversing the statistical radius around the test point, calculating the wind direction difference at each location according to an angle of 1 degree and a radial distance of 5 km. Cumulative amount, when the wind direction retrieved by CLTREC is... and the corresponding wind shear centered on the test point The absolute value of the wind direction angle difference is less than the threshold. If the default is 75 degrees, then calculate according to formula 7; otherwise, the result is 0.

6. A center positioning system based on typhoon water vapor flux vortex characteristics, applying the center positioning method based on typhoon water vapor flux vortex characteristics as described in any one of claims 1 to 5, characterized in that, include: The typhoon water vapor flux calculation module is used to calculate the typhoon circulation field based on radar contour echo data from adjacent time intervals using the CLTREC method. Then, using the ZR relationship between typhoon warm and rain, the gridded radar echoes were converted into gridded hourly rainfall intensity; finally, the gridded wind speed retrieved by the CLTREC method was multiplied by the gridded rainfall intensity to obtain the typhoon wind point water vapor flux data MF. The typhoon center estimation module is used to determine the typhoon center search range for the current time by combining the typhoon center positions of past times with the typhoon movement information predicted in the reports. Then, it finds the position of the maximum correlation coefficient of water vapor flux characteristics in this range through iterative search, and finally determines the initial guessed center of the typhoon for the current time. The optimal typhoon center search module uses the estimated initial typhoon center as the center position and searches for the maximum vortex feature within the typhoon eye radius RA. After determining the maximum vortex feature value, the maximum vortex feature value * 0.95 is determined as the significant vortex feature threshold. Finally, the average position of all regions above the threshold is taken as the typhoon center.

7. A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the center positioning method based on the vortex characteristics of typhoon water vapor flux as described in any one of claims 1 to 5.

8. A computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the center positioning method based on the vortex characteristics of typhoon water vapor flux as described in any one of claims 1 to 5.

9. An information data processing terminal, the information data processing terminal being used to implement the center positioning system based on the vortex characteristics of typhoon water vapor flux as described in claim 6.

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