Typhoon positioning method, system and equipment based on satellite single-channel observation and medium

Abstract

The invention discloses a typhoon positioning method, system and device based on satellite single-channel observation and a medium, and mainly relates to the technical field of typhoon positioning. According to an existing scheme, a historical typhoon center position provided by optimal path data is difficult to meet the requirement of typhoon kernel structure change research on the high-time-precision and real-time typhoon center position; and the typhoon center position of the optimal path is not matched with the geometric center or the power center of typhoon convection or a cloud and rain structure in a satellite cloud picture. Comprising the following steps: selecting a grid test point as a hypothetical initial typhoon center according to a first spatial resolution; in a preset center test area with the initial typhoon center as the center, grid test points are selected according to the second spatial resolution, and change data of the energy spectrum of the 0-wave symmetrical component with the test points as the center in the spectrum expansion radial range of the preset distance area are obtained; and determining a supposed final typhoon center according to whether the change data meets a preset typhoon center condition or not.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of typhoon positioning, and in particular to a typhoon positioning method, system, device and medium based on satellite single-channel observation. BACKGROUND

[0002] The typhoon center position is an indispensable parameter in the vortex initialization of the typhoon numerical prediction model and the typhoon intensity measurement technology. An inaccurate initial typhoon center position often leads to the failure of typhoon path prediction. The dynamics of the typhoon core process and the change of typhoon structure and intensity also need an accurate typhoon center position. For example, the instability of the vortex Rossby wave and the mixing of the potential vorticity are closely related to the radial gradient of the symmetric component of the typhoon potential vorticity, and the characteristics of the symmetric and asymmetric components of the potential vorticity obtained by wave decomposition are crucially dependent on the typhoon center position. In addition, the existence of the vortex Rossby wave in the typhoon is often verified by measuring the moving speed of the inner spiral rain belt that rotates counterclockwise and moves radially outward relative to the typhoon center, which requires an accurate typhoon center position to ensure the accuracy of the measurement value. The historical data of the typhoon center position can be found in the best path data provided by the existing website. The typhoon center position is provided every six hours in the best path, and only represents the center position of the typhoon near the sea surface.

[0003] However, the publication time of the best path data usually has a one-year time lag. Therefore, the historical typhoon center position provided by the best path data is difficult to meet the demand for high time accuracy and real-time typhoon center position for the study of the change of the typhoon core structure. For example, the height of the typhoon center provided by the best path is near the sea surface, which is usually inconsistent with the height of the typhoon structure in the satellite observation field, especially when the vertical structure of the typhoon is tilted. In addition, the typhoon center position of the best path usually refers to the position of the minimum wind speed or the lowest pressure on the sea surface, which may not match the geometric center or dynamic center of the typhoon convection or cloud rain structure in the satellite cloud image. SUMMARY

[0004] The present application provides a typhoon positioning method, system, device and medium based on satellite single-channel observation to solve the problem that the historical typhoon center position provided by the best path data is difficult to meet the demand for high time accuracy and real-time typhoon center position for the study of the change of the typhoon core structure, and the typhoon center position of the best path does not match the geometric center or dynamic center of the typhoon convection or cloud rain structure in the satellite cloud image.

[0005] In a first aspect, the present application provides a typhoon positioning method based on satellite single-channel observation, which comprises: obtaining the brightness temperature field of the typhoon collected by the satellite single channel; defining the position where the regional average brightness temperature minimum value in the brightness temperature field of the typhoon as the initial guessed position; using the azimuth spectrum analysis method, selecting grid test points in a preset guess test area centered on the initial guess position as the initial typhoon center according to a first spatial resolution; using the azimuth spectrum analysis method, selecting grid test points in a preset center test area centered on the initial typhoon center according to a second spatial resolution to obtain variation data of the energy spectrum of the 0 wave symmetrical component in the preset distance area in the spectral expansion radial range centered on the test point; determining the final typhoon center according to whether the variation data meets a preset typhoon center condition; wherein the second spatial resolution is less than the first spatial resolution.

[0006] In an implementation manner of the present application, the brightness temperature field of the typhoon collected by a satellite single channel is acquired; the position where the regional average brightness temperature minimum value in the brightness temperature field of the typhoon is located is defined as the initial guess position, specifically including: acquiring the spatial distribution of the observed brightness temperature in the preset area of the typhoon; acquiring the average brightness temperature distribution of the preset grid resolution in the spatial distribution, and then obtaining the grid position area of the minimum brightness temperature; moving the preset grid resolution by a preset number of degree units of longitude and a preset number of degree units of latitude according to a preset moving direction, and then obtaining the grid position area of the minimum brightness temperature again; determining the middle position of the two grid position areas as the initial guess position.

[0007] In an implementation manner of the present application, using the azimuth spectrum analysis method, selecting grid test points in a preset guess test area centered on the initial guess position as the initial typhoon center according to a first spatial resolution, specifically including: acquiring the test points of the first spatial resolution in the preset guess test area centered on the initial guess position; assuming the test points as the typhoon center and performing azimuth spectrum expansion on the brightness temperature field in the preset different radial range centered on the test points to obtain variation data of the energy spectrum of the 0 wave symmetrical component in the preset distance area in the spectral expansion radial range centered on the different test points; wherein the interval of the azimuth spectrum expansion radial range is 15 km, the energy of the 0 wave symmetrical component refers to the proportion of the 0 wave energy relative to the total wave number energy, and the preset distance area is [A, B] with the unit of km; determining the test point meeting the preset typhoon center condition as the initial typhoon center; wherein, the preset typhoon center condition includes: The 0 wave energy in the radial range of the azimuthal spectrum analysis of A km is greater than the average value of the 0 wave energy in the radial range of A km corresponding to all test points; the 0 wave energy in the radial range of the azimuthal spectrum analysis of B km is greater than the average value of the 0 wave energy in the radial range of B km corresponding to all test points; and the average 0 wave energy in the radial range of the azimuthal spectrum analysis from A km to B km is maximum.

[0008] In an implementation manner of the present application, by using the azimuthal spectrum analysis method, the variation data of the spectral expansion radial range of the 0 wave symmetric component energy spectrum in a preset distance region is obtained by selecting the grid test points in a preset central test region with the initial typhoon center as the center and at a second spatial resolution; and the assumed final typhoon center is determined according to whether the variation data satisfies a preset typhoon center condition, specifically including: The test points in the preset central test region with the initial typhoon center as the center and at the second spatial resolution are obtained. The test points are assumed as the typhoon center, and the azimuthal spectrum expansion is performed on the brightness temperature field in the preset different radial ranges with the test points as the center, to obtain the variation data of the spectral expansion radial range of the 0 wave symmetric component energy spectrum in the preset distance region with different test points as the center; wherein the interval of the azimuthal spectrum expansion radial range is 15 km, the energy of the 0 wave symmetric component refers to the proportion of the 0 wave energy relative to the total wave number energy, and the preset distance region is [A, B] with the unit of km; The test point satisfying the preset typhoon center condition is determined as the assumed final typhoon center.

[0009] In a second aspect, the present application provides a typhoon positioning system based on satellite single-channel observation, which comprises: A position determination module is configured to obtain the brightness temperature field of the typhoon collected by the satellite single channel, and define the position where the region average brightness temperature minimum value in the brightness temperature field of the typhoon as the initial guessed position. An initial positioning module is configured to use the azimuthal spectrum analysis method to select the grid test points in a preset guess test region with the initial guessed position as the center and at a first spatial resolution, as the assumed initial typhoon center. A final positioning module is configured to use the azimuthal spectrum analysis method to select the grid test points in a preset central test region with the initial typhoon center as the center and at a second spatial resolution, to obtain the variation data of the spectral expansion radial range of the 0 wave symmetric component energy spectrum in a preset distance region with the test points as the center; and determine the assumed final typhoon center according to whether the variation data satisfies a preset typhoon center condition; wherein the second spatial resolution is less than the first spatial resolution.

[0010] In an implementation manner of the present application, the position determination module comprises a position determination unit, Obtaining the spatial distribution of the observed brightness temperature in a preset area of the typhoon; Obtaining the average brightness temperature distribution of the preset grid resolution in the spatial distribution, and then obtaining the grid point position area of the minimum brightness temperature; Moving the preset grid resolution eastward by a preset number of longitude units and northward by a preset number of latitude units, and again obtaining the grid point position area of the minimum brightness temperature; Determining the middle position of the two grid point position areas as the initial guess position.

[0011] In an implementation manner of the present application, the initial positioning module comprises an initial positioning unit, Obtaining a test point of the first spatial resolution in a preset guess test area with the initial guess position as the center; Assuming the test point as the typhoon center and performing azimuth spectrum expansion on the brightness temperature field in a preset different radial range with the test point as the center, to obtain the variation data of the energy spectrum of the 0 wave symmetrical component in the preset distance area in the spectrum expansion radial range with different test points as the center; wherein the interval of the azimuth spectrum expansion radial range is 15 km, the energy of the 0 wave symmetrical component refers to the proportion of the 0 wave energy relative to the total wave number energy, and the preset distance area is [A, B] with the unit of KM; Determining the test point meeting the preset typhoon center condition as the assumed initial typhoon center. The preset typhoon center condition comprises: The 0 wave energy in the A km azimuth spectrum analysis radial range is greater than the average value of the 0 wave energy in the A km radial range corresponding to all test points; the 0 wave energy in the B km azimuth spectrum analysis radial range is greater than the average value of the 0 wave energy in the B km radial range corresponding to all test points; and the average 0 wave energy in the azimuth spectrum analysis radial range from A km to B km is maximum.

[0012] In an implementation manner of the present application, the final positioning module comprises a final positioning unit, Obtaining a test point of the second spatial resolution in a preset center test area with the initial typhoon center as the center; Assuming the test point as the typhoon center and performing azimuth spectrum expansion on the brightness temperature field in a preset different radial range with the test point as the center, to obtain the variation data of the energy spectrum of the 0 wave symmetrical component in the preset distance area in the spectrum expansion radial range with different test points as the center; wherein the interval of the azimuth spectrum expansion radial range is 15 km, the energy of the 0 wave symmetrical component refers to the proportion of the 0 wave energy relative to the total wave number energy, and the preset distance area is [A, B] with the unit of KM; Determining the test point meeting the preset typhoon center condition as the assumed final typhoon center.

[0013] In a third aspect, the application provides a typhoon positioning device based on satellite single-channel observation, the device comprising: a processor; and a memory having stored thereon executable code that, when executed, causes the processor to perform a typhoon positioning method based on satellite single-channel observation according to any one of the preceding aspects.

[0014] In a fourth aspect, the application provides a non-volatile computer storage medium having stored thereon computer instructions that, when executed, implement a typhoon positioning method based on satellite single-channel observation according to any one of the preceding aspects.

[0015] As can be seen from the above technical solutions, the application has the following advantages: The existing typhoon positioning scheme uses data of observed brightness temperature data of multiple channels of a satellite, and the application uses brightness temperature field data of a typhoon collected by a satellite single channel. The data amount is reduced compared with the existing scheme, and the data processing time is reduced on the basis of reducing the data processing amount. In addition, unlike the scheme of analyzing the entire region in the prior art, the application first locates the initial guess position, and in the process of gradually accurately positioning the typhoon position, the search area is also reduced, and the processing time is reduced on the basis of reducing the area amount.

[0016] The application directly processes satellite single-channel real-time brightness temperature field data, and breaks through the one-year lag limitation of the traditional best path data. The initial guess position generation mechanism based on the minimum value of the brightness temperature field, combined with the double-resolution iteration (first low-precision preliminary screening in a large range, and then high-precision confirmation in a small range) of the azimuth spectrum analysis method, realizes the minute-level dynamic tracking of the typhoon center. The application changes the data source from relying on historical sea surface weather station observation to directly analyzing satellite real-time remote sensing data, so that the typhoon core structure research can obtain center position information completely synchronized with the satellite observation timestamp, which is especially suitable for scenes such as rapid strengthening or path mutation of a typhoon that need immediate response.

[0017] The application defines the typhoon center by the brightness temperature field characteristics (rather than the sea surface pressure / wind speed), which fundamentally solves the problem of deviation between the dynamic center and the geometric center of the cloud system in the traditional method. The azimuth spectrum analysis method can effectively capture the symmetric center of the spiral band of the typhoon convective cloud cluster or the closed circulation center of the eye wall in the preset guess test area. This positioning method based on the cloud top radiation characteristics is more consistent with the true three-dimensional characteristics of the tilted typhoon vertical structure, especially when the typhoon occurs in a baroclinic structure tilt, the positioning result is highly consistent with the morphological characteristics of the satellite visible light / infrared cloud image, which provides an accurate spatial reference benchmark for studying the thermal-dynamic coupling process of the typhoon core. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the present application, the drawings required to be used in the description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0019] Figure 1 is a flow chart of a typhoon positioning method based on satellite single-channel observation provided by an embodiment of the present application.

[0020] Figure 2 is a spatial distribution diagram of observed brightness temperature of ATMS channel 18 in typhoon Sandy and its periphery provided by an embodiment of the present application.

[0021] Figure 3 is a spatial distribution diagram of brightness temperature of typhoon Sandy and its periphery provided by an embodiment of the present application.

[0022] Figure 4 is a diagram of average brightness temperature distribution with 1.5° grid resolution provided by an embodiment of the present application.

[0023] Figure 5 is a diagram of an initial guess position provided by an embodiment of the present application.

[0024] Figure 6 is a diagram of observed brightness temperature field of ATMS water vapor channel 18 and a test point with 0.15° resolution provided by an embodiment of the present application.

[0025] Figure 7 is a diagram of distribution of energy spectrum of 0 wave symmetrical component of brightness temperature with different test points as center in a spectral expansion radial range of 30-360 km provided by an embodiment of the present application.

[0026] Figure 8 is a diagram of a test domain with a range of 2° provided by an embodiment of the present application.

[0027] Figure 9 is a diagram of change of 0 wave energy proportion with radial range obtained by azimuthal spectral expansion with each test point in the test domain as center provided by an embodiment of the present application.

[0028] Figure 10 is a diagram of change of energy proportion of 0-4 wave components with spectral expansion radial range with the typhoon center determined by ATMS and the typhoon center of the best path as center respectively provided by an embodiment of the present application.

[0029] Figure 11 is a schematic diagram of a path of a typhoon Sandy and a best path of the typhoon determined by the ATMS channel 18 and the MHS channel 5 and the observation brightness temperature and the azimuth spectrum analysis positioning method provided in an embodiment of the present application.

[0030] Figure 12 is a schematic diagram of a deviation of a typhoon center from a best path of the typhoon center determined by the ATMS and the MHS and the azimuth spectrum analysis positioning method provided in an embodiment of the present application.

[0031] Figure 13 is a schematic diagram of an internal structure of a typhoon positioning system based on satellite single-channel observation provided in an embodiment of the present application.

[0032] Figure 14 is a schematic diagram of an internal structure of a typhoon positioning device based on satellite single-channel observation provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present application.

[0034] Those skilled in the art should understand that the embodiments described below are only preferred embodiments of the present disclosure, and do not mean that the present disclosure can only be implemented by the preferred embodiments. The preferred embodiments are only used to explain the technical principles of the present disclosure, and are not used to limit the protection scope of the present disclosure. Based on the preferred embodiments provided in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts still fall within the protection scope of the present disclosure.

[0035] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or further include elements inherent in such processes, methods, articles or devices. Without more limitations, the element defined by the statement "including a" does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0036] The azimuth spectrum analysis positioning method of the application is realized based on a python program language. The application adopts an observed brightness temperature of an ATMS (Atmospheric Moisture Sounding Channel) water vapor channel 18 (183.31 7.0 GHz). The weight function peak of the ATMS water vapor sounding channel 18 is about 800 hPa, which can provide a detailed water vapor structure distribution of the lower troposphere of a typhoon and has less influence from the ground than other window channel. Generally, the axisymmetric component of the radar reflectivity field or the satellite observed brightness temperature field covering the typhoon center is always dominant. The azimuth spectrum analysis method can extract the symmetric component (0 wave component) and the asymmetric component of the brightness temperature field with any position in the satellite observed brightness temperature field as the center, and the center position corresponding to the maximum symmetric component energy is taken as the typhoon center position.

[0037] The technical solutions of the embodiments of the application will be described in detail below with reference to the drawings.

[0038] The embodiment provides a typhoon positioning method based on satellite single-channel observation, as shown in Figure 1 The method provided by the embodiment of the application mainly includes the following steps. In step 110, the brightness temperature field of the typhoon collected by the satellite single channel is obtained, and the position where the minimum regional average brightness temperature in the brightness temperature field of the typhoon is located is defined as the initial guess position.

[0039] In some embodiments, the position where the minimum regional average brightness temperature in the brightness temperature field of the typhoon is located is defined as the initial guess position, which specifically includes: Obtaining the spatial distribution of the observed brightness temperature in the preset area of the typhoon; Obtaining the average brightness temperature distribution of the preset grid resolution in the spatial distribution, and then obtaining the grid position area of the minimum brightness temperature; Moving the preset grid resolution eastward by a preset number of longitude units and northward by a preset number of latitude units, and then obtaining the grid position area of the minimum brightness temperature again; Determining the middle position of the two grid position areas as the initial guess position.

[0040] Based on the above description, it should be noted that this step can be specifically: to determine the typhoon center test area of the azimuth spectrum expansion, a limited and effective calculation domain is established, and the first step of the azimuth spectrum analysis positioning method is to determine the initial guess position or the initial guess position of the target typhoon. Considering that the eye wall and the inner core rain band near the eye wall in the satellite observed brightness temperature field usually show a low brightness temperature area, the application defines the position where the minimum regional average brightness temperature in the brightness temperature field of the typhoon is located as the initial guess position. As an example: Figure 2The figure shows the spatial distribution of brightness temperature observed by ATMS Channel 18 in and around Typhoon Sandy at 1438 UTC on October 24, 2012 (it should be noted that W in the figure represents west longitude, N represents north latitude, and K represents Kelvin, which represents the unit of temperature in the unit system). Figure 3 Shown is the spatial distribution of brightness temperature in and around Typhoon Sandy at 1756 UTC on October 22, 2012. While Sandy did not have a distinct eye at this time, organized low-brightness-temperature convective structures were still present. Figure 4 Showing 1.5 Average brightness temperature distribution at a grid resolution of 1.5 (units are current latitude and longitude units: °), black " " marks the grid position of the lowest average brightness temperature. In addition, this application will be 1.5 The grid position of 1.5 is moved 0.75 degrees to the east and north (units are the existing latitude and longitude units: °), and the brightness temperature field is regionally averaged again. Gray" " marks the grid point location of the lowest average brightness temperature value in the moved grid. The average brightness temperature fields on two staggered grids are used to avoid the low brightness temperature areas caused by the typhoon eyewall or inner core rainband appearing between the coarse grid points. The grid points where the two lowest average brightness temperature values ​​are located are (-76.8W, 16.8N) and (-77.55W, 16.05N), and their middle position (-77.175W, 16.425N) is defined as the initial guess position. Figure 5 The process of determining its initial guess position is shown.

[0041] Step 120: Using the azimuth spectrum analysis method, within a preset guess test area centered on the initial guess position, select grid test points at a first spatial resolution as the assumed initial typhoon center.

[0042] Among them, using the azimuth spectrum analysis method, within the preset guess test area centered on the initial guess position, grid test points are selected at the first spatial resolution as the hypothetical initial typhoon center, specifically including: Acquire a test point of a first spatial resolution within a preset guess test area centered on an initial guess position; The test point is assumed to be the typhoon center, and the brightness temperature field is expanded in azimuth within different preset radial ranges centered on the test point. The energy spectrum of the zero-wave symmetric component centered on different test points is obtained. The radial range of the spectrum expansion is varied in the preset distance area. The interval of the radial range of the azimuth spectrum expansion is 15 km. The energy spectrum of the zero-wave symmetric component refers to the proportion of the zero-wave energy to the total wavenumber energy. The preset distance area is [A, B], and the unit is km. Determine the test point that meets the preset typhoon center conditions as the assumed initial typhoon center; wherein the preset typhoon center condition comprises: The 0 wave energy in the A km azimuthal spectrum analysis radial range is greater than the average value of the 0 wave energy in the A km radial range corresponding to all test points; the 0 wave energy in the B km azimuthal spectrum analysis radial range is greater than the average value of the 0 wave energy in the B km radial range corresponding to all test points; and the average 0 wave energy in the azimuthal spectrum analysis radial range from A km to B km is maximum.

[0043] For example, A KM represents 30 KM, and B KM represents 360 KM.

[0044] Based on the above description, it needs to be explained that the step can be specifically: After the initial guess position is determined, the process of the azimuthal spectrum analysis positioning method for determining the typhoon center is illustrated next. In general, the azimuthal spectrum analysis positioning method performs twice azimuthal spectrum analysis on the observed brightness temperature field containing the typhoon. The first time of azimuthal spectrum analysis is to select test points with a resolution of 0.15 0.15 (unit: existing latitude and longitude unit: °) as the assumed typhoon center from a larger test area (4 4, unit: existing latitude and longitude unit: °) centered on the initial guess position. The first time of azimuthal spectrum analysis selects the assumed typhoon center from the larger test area, which is to avoid that the azimuthal spectrum analysis deviates from the effective analysis area due to the initial guess position being too far from the real typhoon center. Figure 6 The observed brightness temperature field of ATMS water vapor channel 18 at 1438 UTC on October 24, 2012 and the test points with a resolution of 0.15 0.15° are shown. These test points are contained in the 4 4° square test area centered on the initial guess position. These test points are assumed to be the typhoon center and the brightness temperature field is azimuthally spectrum expanded in different radial ranges with them as the center, to obtain the energy of the 0 wave symmetrical component with different test points as the center varying with the spectrum expansion radial range. Figure 7The energy spectrum of the 0-wave symmetrical component of the brightness temperature centered on different test points is shown in the spectral expansion radial range of 30-360 km. The interval of the azimuthal spectral expansion radial range is 15 km. The 0-wave energy spectrum here refers to the proportion of the 0-wave energy relative to the total wave energy (60). According to the distribution characteristics of the 0-wave energy of the brightness temperature corresponding to different test points in the spectral expansion radial range of 30-360 km, the preliminary typhoon center position is determined, that is, the test point that meets the following conditions will be selected as the typhoon center position determined by the first azimuthal spectral analysis: (1) the 0-wave energy in the 30 km azimuthal spectral analysis radial range is greater than the average value of the 0-wave energy in the 30 km radial range of all test points; (2) the 0-wave energy in the 360 km azimuthal spectral analysis radial range is greater than the average value of the 0-wave energy in the 360 km radial range of all test points; (3) the average 0-wave energy in the azimuthal spectral analysis radial range from 30 km to 360 km is the maximum. These conditions are based on the assumption that the closer the test point is to the true typhoon center, the greater the energy of the 0-wave component centered on it. Figure 7 The radial distribution of the maximum 0-wave symmetrical component energy meeting the above conditions is represented by a curve of a hollow triangle, which is much higher than the energy of the symmetrical component centered on the typhoon center of the best path, the initial guess position and all other test points. Figure 6 The typhoon center position determined by the first azimuthal spectral analysis is represented by a hollow triangle, which is about 50 km away from the typhoon center of the best path.

[0045] Step 130, using the azimuthal spectral analysis method, selecting grid test points in a preset central test area centered on the initial typhoon center at a second spatial resolution, obtaining the variation data of the energy spectrum of the 0-wave symmetrical component centered on the test points in the spectral expansion radial range of the preset distance region; determining the final typhoon center according to whether the variation data meets the preset typhoon center condition.

[0046] Among them, the second spatial resolution is less than the first spatial resolution.

[0047] This step can be specifically: Obtaining the test points of the second spatial resolution in the preset central test area centered on the initial typhoon center; Assuming the test points as the typhoon center and performing azimuthal spectral expansion on the brightness temperature field in the preset different radial range centered on the test points, obtaining the variation data of the energy spectrum of the 0-wave symmetrical component centered on different test points in the spectral expansion radial range of the preset distance region; wherein the interval of the azimuthal spectral expansion radial range is 15 km, the energy of the 0-wave symmetrical component refers to the proportion of the 0-wave energy relative to the total wave energy, and the preset distance region is [A, B] with the unit of km; The test point satisfying the preset typhoon center condition is determined as the final typhoon center.

[0048] Based on the above description, it needs to be explained that this step can be specifically: To further improve the positioning accuracy, the azimuth spectrum analysis positioning method takes the typhoon center position determined by the first azimuth spectrum analysis as the center, and again establishes a test domain with a range of 2° 2° (such as Figure 8 , W represents west longitude, N represents north latitude, and K represents Kelvin, which represents the temperature unit in the unit system), and takes the test point with a resolution of 0.05° 0.05° in the test domain as the center to perform azimuth spectrum analysis again. Figure 9 The figure shows the change of the 0 wave energy proportion with the radial range obtained by performing azimuth spectrum expansion with each test point in the test domain as the center. The hollow circle curve represents the radial distribution of the maximum symmetric component energy, which is much higher than the symmetric component energy with the typhoon center of the best path, the typhoon center determined by the first azimuth spectrum analysis, and all other test points as the center. Figure 8 The typhoon center determined by the second azimuth spectrum analysis, i.e. the typhoon center finally determined by the azimuth spectrum analysis positioning method, is represented by the hollow circle, which has a very small deviation from the typhoon center of the best path and is located in the typhoon warm core.

[0049] The first condition for determining the maximum symmetric component energy is to ensure that the symmetric energy in a smaller spectrum expansion radial range is higher, because the typhoon eye is usually highly axisymmetric. The second and third conditions for determining the maximum symmetric component energy are to avoid the situation that the 0 wave energy is abnormally large in certain radial ranges due to the local brightness temperature symmetric structure of the typhoon, so as to ensure that the finally determined maximum symmetric component energy is caused by the overall brightness temperature structure of the typhoon. For example Figure 7 and Figure 9 The 0 wave energy distribution represented by the cyan curve is greater than the symmetric component energy with the finally determined typhoon center as the center in a smaller spectrum expansion radial range, but much smaller than the symmetric component energy with the finally determined typhoon center as the center in a larger spectrum expansion radial range. Figure 7 The 0 wave energy distribution represented by the purple curve is opposite to the 0 wave energy distribution represented by the cyan curve. In addition, the radial range of the azimuth spectrum analysis is set to 30-360 km. In a radial range less than 30 km, the brightness temperature data used for azimuth spectrum analysis is very small. The strong asymmetric outer spiral rainband structure is usually distributed in the peripheral area more than 500 km away from the typhoon center. In order to ensure that the axisymmetric component of the typhoon always dominates, the maximum radial range radius of the azimuth spectrum expansion is empirically set to 360 km. For example Figure 7 and Figure 9It is shown that the 0 wave energy fraction is more than 50% in the 360 km radial range, which is higher than the energy fraction of other wave numbers. Figure 10 The energy fraction of 0-4 wave components with respect to the radial range of spectral expansion is shown for the typhoon center determined by ATMS and the typhoon center of the best track, respectively. The energy fraction of 0 wave component with respect to the typhoon center determined by ATMS is always larger than that of the typhoon center of the best track, and is more than 80% in the 210 km range, then gradually decreases with the increase of the radial range of spectral expansion. Figure 10 The energy fraction of 0 wave component with respect to the typhoon center determined by ATMS is always higher than that of other wave numbers, which indicates that the symmetric component of the whole typhoon structure always dominates in the 30-360 km radial range of spectral expansion.

[0050] In addition, the present application can also take advantage of the similar channel characteristics of MHS (Microwave Humidity Sounder) water vapor channel 5 and ATMS water vapor channel 18, their field of view diameters (16 km) and weight function peak heights (800 hPa) are the same, and they can both provide detailed water vapor structure information in the lower and middle troposphere of the typhoon. In order to increase the observation frequency of the typhoon, we use the observed brightness temperature data of ATMS water vapor channel 18 and MHS water vapor channel 5 and determine the typhoon center by the azimuthal spectral analysis positioning method. Figure 11 The path of typhoon Sandy determined by the observed brightness temperature data of ATMS channel 18 and MHS channel 5 and by the azimuthal spectral analysis positioning method from 1200 UTC on October 21, 2012 to 1800 UTC on October 31, 2012 and the best track of the typhoon are shown. It can be seen that the two paths are very close (the maximum distance is less than 50 km) Figure 11 In the table, TD: Tropical Depression, TS: Tropical Storm, H1: Hurricane Category 1, H2: Hurricane Category 2, H3: Hurricane Category 3). Figure 12The deviation of the typhoon center determined by the first step and the second step of the orientation spectrum analysis positioning method of the ATMS and the MHS relative to the typhoon center of the best path is shown. In terms of the positioning deviation of the typhoon Sandy throughout the life history, the positioning deviation of the second step or the final step of the orientation spectrum analysis positioning method is generally lower than that of the first step. Relative to the typhoon center of the best path, the average positioning deviation of the typhoon Sandy is about 35.8 km. During 1800 UTC on October 24, 2012 to 1800 UTC on October 29, the intensity of the typhoon Sandy is high, and the positioning deviation is generally lower than the average value. While the intensity of the typhoon Sandy is low, the positioning deviation is generally higher than the average value.

[0051] In addition, the application Figure 13 A typhoon positioning system based on satellite single-channel observation is provided for an embodiment of the application. As shown in the Figure 13 The system provided by the embodiment of the application mainly comprises: The position determination module 210 is configured to acquire the brightness temperature field of the typhoon collected by the satellite single channel; and define the position where the area average brightness temperature minimum value in the brightness temperature field of the typhoon is located as the initial guess position.

[0052] The position determination module 210 comprises a position determination unit configured to acquire the spatial distribution of the observed brightness temperature in the preset area of the typhoon; acquire the average brightness temperature distribution of the preset grid resolution in the spatial distribution, and then obtain the grid point position area of the minimum brightness temperature; move the preset grid resolution eastward by a preset number of longitude units and northward by a preset number of latitude units, and again obtain the grid point position area of the minimum brightness temperature; determine the middle position of the two grid point position areas as the initial guess position.

[0053] The initial positioning module 220 is configured to use the orientation spectrum analysis method to select grid test points in a preset guess test area centered on the initial guess position as the assumed initial typhoon center according to a first spatial resolution.

[0054] The initial positioning module 220 comprises an initial positioning unit, configured to acquire the test points of the first spatial resolution in the preset guess test area centered on the initial guess position; assume the test points as the typhoon center and perform orientation spectrum expansion on the brightness temperature field in a preset different radial range centered on the test points to obtain the variation data of the energy spectrum of the 0 wave symmetrical component in the preset distance area in the spectrum expansion radial range with different test points as the center; wherein the interval of the spectrum expansion radial range is 15 km, the energy of the 0 wave symmetrical component refers to the proportion of the 0 wave energy relative to the total wave number energy, and the preset distance area is [A, B] with the unit of km. determining the test point satisfying the preset typhoon center condition as the assumed initial typhoon center; The preset typhoon center condition comprises: The 0 wave energy in the A km azimuth spectrum analysis radial range is greater than the average value of the 0 wave energy in the A km radial range corresponding to all test points; the 0 wave energy in the B km azimuth spectrum analysis radial range is greater than the average value of the 0 wave energy in the B km radial range corresponding to all test points; and the average 0 wave energy in the azimuth spectrum analysis radial range from A km to B km is maximum.

[0055] The final positioning module 230 is configured to utilize the azimuth spectrum analysis method to select grid test points in a preset center test area centered on the initial typhoon center at a second spatial resolution, to obtain variation data of the energy spectrum of the 0 wave symmetric component in the preset distance area in the spectrum expansion radial range centered on the test points; and determine the assumed final typhoon center according to whether the variation data satisfies the preset typhoon center condition; wherein the second spatial resolution is less than the first spatial resolution.

[0056] The final positioning module 230 comprises a final positioning unit, The test points in the preset center test area centered on the initial typhoon center at the second spatial resolution are obtained. The test points are assumed to be typhoon centers, and the azimuth spectrum expansion is performed on the brightness temperature field in the preset different radial ranges centered on the test points, to obtain variation data of the energy spectrum of the 0 wave symmetric component in the preset distance area in the spectrum expansion radial range centered on the different test points; wherein the interval of the azimuth spectrum expansion radial range is 15 km, the energy of the 0 wave symmetric component refers to the proportion of the 0 wave energy relative to the total wave number energy, and the preset distance area is [A, B] with the unit of km; The test point satisfying the preset typhoon center condition is determined as the assumed final typhoon center.

[0057] The above is the method embodiment in the present application. Based on the same inventive concept, the present application embodiment also provides a typhoon positioning device based on satellite single-channel observation. As shown in the figure, the device comprises a processor and a memory having executable code stored thereon, when the executable code is executed, the processor executes the typhoon positioning method based on satellite single-channel observation as one of the above embodiments. Figure 14

[0058] ​Specifically, the server end acquires a brightness temperature field of a typhoon collected by a satellite single channel; defines a position where a minimum regional average brightness temperature in the brightness temperature field of the typhoon is located as an initial guess position; selects a grid test point in a preset guess test area centered on the initial guess position as an assumed initial typhoon center according to a first spatial resolution by using a bearing spectrum analysis method; selects a grid test point in a preset center test area centered on the initial typhoon center according to a second spatial resolution by using the bearing spectrum analysis method, and obtains variation data of a spectrum expansion radial range of an energy spectrum of a 0 wave symmetrical component in a preset distance area centered on the test point; determines a final typhoon center according to whether the variation data meets a preset typhoon center condition; and the second spatial resolution is less than the first spatial resolution.

[0059] In addition, the embodiment of the present application further provides a nonvolatile computer storage medium, which has executable instructions stored thereon, and the executable instructions, when executed, realize a typhoon positioning method based on satellite single channel observation as described above.

[0060] The above description of disclosed embodiments enables those skilled in the art to carry out or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A typhoon positioning method based on satellite single-channel observation, characterized in that: The method comprises: Obtain the brightness temperature field of the typhoon collected by a single satellite channel; define the location of the lowest regional average brightness temperature in the brightness temperature field of the typhoon as the initial guess position; Using the azimuth spectrum analysis method, within the preset guess test area centered on the initial guess position, grid test points are selected at the first spatial resolution as the hypothetical initial typhoon center; Using the azimuth spectrum analysis method, grid test points are selected according to the second spatial resolution within the preset central test area centered on the initial typhoon center, and the change data of the radial range of the spectrum expansion of the energy spectrum of the 0-wave symmetric component centered on the test point in the preset distance area are obtained; based on whether the change data meets the preset typhoon center conditions, the hypothetical final typhoon center is determined; wherein the second spatial resolution is smaller than the first spatial resolution.

2. The typhoon positioning method based on satellite single-channel observation according to claim 1, characterized in that: The location of the lowest regional average brightness temperature in the typhoon's brightness temperature field is defined as the initial guess location, specifically including: Obtain the spatial distribution of observed brightness temperature within the preset area of ​​the typhoon; Obtain the average brightness temperature distribution of the preset grid resolution in the spatial distribution, and then obtain the grid location area with the lowest brightness temperature; The preset grid resolution is moved in a preset moving direction by a preset number of degrees of longitude units and a preset number of degrees of latitude units to obtain the grid point location area with the lowest brightness temperature again; The middle position of the two grid position areas is determined as the initial guess position.

3. The typhoon positioning method based on satellite single-channel observation according to claim 1, characterized in that: Using the azimuth spectrum analysis method, within the preset guess test area centered on the initial guess position, grid test points are selected at the first spatial resolution as the hypothetical initial typhoon center, specifically including: Acquire a test point of a first spatial resolution within a preset guess test area centered on an initial guess position; The test point is assumed to be the typhoon center, and the brightness temperature field is expanded in azimuth within different preset radial ranges centered on the test point. The energy spectrum of the zero-wave symmetric component centered on different test points is obtained. The radial range of the spectrum expansion is varied in the preset distance area. The interval of the radial range of the azimuth spectrum expansion is 15 km. The energy spectrum of the zero-wave symmetric component refers to the proportion of the zero-wave energy to the total wavenumber energy. The preset distance area is [A, B], and the unit is km. Determine the test point that meets the preset typhoon center conditions as the assumed initial typhoon center; Among them, the preset typhoon center conditions include: The 0-wave energy within the radial range of A km azimuth spectrum analysis is greater than the average 0-wave energy within the radial range of A km corresponding to all test points; the 0-wave energy within the radial range of B km azimuth spectrum analysis is greater than the average 0-wave energy within the radial range of B km corresponding to all test points; the average 0-wave energy within the radial range of azimuth spectrum analysis from A km to B km is the largest.

4. The typhoon positioning method based on satellite single-channel observation according to claim 1, characterized in that: Using the azimuth spectrum analysis method, within the preset central test area centered on the initial typhoon center, grid test points are selected at the second spatial resolution to obtain the radial range variation data of the energy spectrum of the zero-wave symmetric component centered on the test point in the preset distance area. Based on whether the variation data meets the preset typhoon center conditions, the hypothetical final typhoon center is determined, specifically including: Acquire test points of the second spatial resolution within a preset central test area centered on the initial typhoon center; The test point is assumed to be the typhoon center, and the brightness temperature field is expanded in azimuth within different preset radial ranges centered on the test point. The energy spectrum of the zero-wave symmetric component centered on different test points is obtained. The radial range of the spectrum expansion is varied in the preset distance area. The interval of the radial range of the azimuth spectrum expansion is 15 km. The energy spectrum of the zero-wave symmetric component refers to the proportion of the zero-wave energy to the total wavenumber energy. The preset distance area is [A, B], and the unit is km. The test point that meets the preset typhoon center conditions is determined as the hypothetical final typhoon center.

5. A typhoon positioning system based on satellite single-channel observation, characterized in that: The system comprises: A position determination module is used to obtain the brightness temperature field of the typhoon collected by a single satellite channel; the position where the lowest value of the regional average brightness temperature in the brightness temperature field of the typhoon is located is defined as the initial guess position; An initial positioning module is used to select grid test points at a first spatial resolution within a preset guess test area centered on the initial guess position using an azimuth spectrum analysis method as the assumed initial typhoon center; The final positioning module is used to use the azimuth spectrum analysis method to select grid test points according to the second spatial resolution within a preset central test area centered on the initial typhoon center, and obtain the change data of the radial range of the spectrum expansion of the energy spectrum of the 0-wave symmetric component centered on the test point in the preset distance area; determine the hypothetical final typhoon center based on whether the change data meets the preset typhoon center conditions; wherein the second spatial resolution is smaller than the first spatial resolution.

6. The typhoon positioning system based on satellite single-channel observation according to claim 5, characterized in that: The location determination module includes a location determination unit, Used to obtain the spatial distribution of observed brightness temperature within the preset area of ​​the typhoon; Obtain the average brightness temperature distribution of the preset grid resolution in the spatial distribution, and then obtain the grid location area with the lowest brightness temperature; Move the preset grid resolution eastward by a preset number of longitude units and northward by a preset number of latitude units to obtain the grid point location area with the lowest brightness temperature again; The middle position of the two grid position areas is determined as the initial guess position.

7. The typhoon positioning system based on satellite single-channel observation according to claim 5, characterized in that: The initial positioning module includes an initial positioning unit, Used to obtain a test point of a first spatial resolution within a preset guess test area centered on an initial guess position; The test point is assumed to be the typhoon center, and the brightness temperature field is expanded in azimuth within different preset radial ranges centered on the test point. The energy spectrum of the zero-wave symmetric component centered on different test points is obtained. The radial range of the spectrum expansion is varied in the preset distance area. The interval of the radial range of the azimuth spectrum expansion is 15 km. The energy spectrum of the zero-wave symmetric component refers to the proportion of the zero-wave energy to the total wavenumber energy. The preset distance area is [A, B], and the unit is km. Determine the test point that meets the preset typhoon center conditions as the assumed initial typhoon center; Among them, the preset typhoon center conditions include: The 0-wave energy within the radial range of A km azimuth spectrum analysis is greater than the average 0-wave energy within the radial range of A km corresponding to all test points; the 0-wave energy within the radial range of B km azimuth spectrum analysis is greater than the average 0-wave energy within the radial range of B km corresponding to all test points; the average 0-wave energy within the radial range of azimuth spectrum analysis from A km to B km is the largest.

8. The typhoon positioning system based on satellite single-channel observation according to claim 5, characterized in that: The final positioning module includes a final positioning unit, Acquire test points of the second spatial resolution within a preset central test area centered on the initial typhoon center; The test point is assumed to be the typhoon center, and the brightness temperature field is expanded in azimuth within different preset radial ranges centered on the test point. The energy spectrum of the zero-wave symmetric component centered on different test points is obtained. The radial range of the spectrum expansion is varied in the preset distance area. The interval of the radial range of the azimuth spectrum expansion is 15 km. The energy spectrum of the zero-wave symmetric component refers to the proportion of the zero-wave energy to the total wavenumber energy. The preset distance area is [A, B], and the unit is km. The test point that meets the preset typhoon center conditions is determined as the hypothetical final typhoon center.

9. A typhoon positioning device based on satellite single-channel observation, characterized in that: The device comprises: processor; and a memory storing executable code thereon, which, when the executable code is executed, causes the processor to execute a typhoon positioning method based on satellite single-channel observation as described in any one of claims 1 to 4.

10. A non-volatile computer storage medium, characterized in that Computer instructions are stored thereon, and when the computer instructions are executed, they implement a typhoon positioning method based on satellite single-channel observation as described in any one of claims 1 to 4.

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