Method and device for determining visibility in rainfall weather

Abstract

The invention provides a determination method and a determination device for rainfall weather visibility. The determination method comprises the following steps: acquiring raindrop particle size distribution data correspondingly collected in a preset sampling period for a target observation area where rainfall weather occurs; based on the raindrop particle size distribution data, respectively determining a rainfall intensity value and a raindrop spectrum distribution parameter corresponding to the target observation area in a preset sampling period; based on the raindrop particle size distribution data, the raindrop spectrum distribution parameter and a preset attenuation efficiency factor parameter, determining a corresponding raindrop group extinction coefficient of the target observation area in a preset sampling period; and based on the rainfall intensity value, the raindrop group extinction coefficient and the raindrop spectrum distribution parameter, determining a corresponding visibility value of the target observation area in a preset sampling period. According to the method, the adaptability, the real-time performance, the accuracy and the efficiency of rainfall weather visibility calculation are improved.

Description

Technical Field

[0001] This application relates to the field of meteorological data processing technology, and in particular to a method and apparatus for determining visibility during rainfall. Background Technology

[0002] Visibility is one of the important meteorological indicators in many fields such as aviation, navigation, and road traffic. It directly affects travel safety and work efficiency. Under severe weather conditions, such as heavy rain, thunderstorms, and sleet, rain particles will have a significant scattering and absorption effect on the propagation of light waves, resulting in a decrease in atmospheric transmittance and thus reducing horizontal visibility. At present, the main methods for calculating visibility in rainy weather include empirical formula methods, Mie scattering model methods, and particle optical model methods based on ray tracing.

[0003] Among them, the empirical formula method cannot fully reflect the influence of different precipitation particle shapes, size distributions and optical scattering characteristics due to the large differences in data under different regions and different precipitation types; the Mie scattering model method is only applicable to spherical water droplets and has a large computational load; the particle optical model method based on ray tracing has a large computational load and is difficult to apply directly in specific scenarios in real time. The above methods reduce the adaptability and real-time performance of visibility calculation in rainy weather, and thus reduce the accuracy and efficiency of visibility calculation in rainy weather. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a method and apparatus for determining visibility during rainfall. By acquiring raindrop size distribution data of a target observation area during rainfall in real time within a preset sampling period, the rainfall intensity and raindrop spectral distribution parameters of the target observation area are determined. Based on the physical model between the raindrop spectral distribution parameters and rainfall intensity and the raindrop population extinction coefficient, the visibility value of the target observation area within the preset sampling period is calculated. This method considers the physical process of particle scattering in the theoretical model and adapts to different precipitation types and climatic conditions, thereby improving the adaptability and real-time performance of visibility calculation during rainfall, and thus improving the accuracy and efficiency of visibility calculation during rainfall.

[0005] This application provides a method for determining visibility during rainfall, the method comprising: Acquire raindrop size distribution data collected within a preset sampling period for the target observation area where rainfall occurs; Based on the raindrop size distribution data, the rainfall intensity value and raindrop spectral distribution parameters corresponding to the target observation area within the preset sampling period are determined respectively; Based on the raindrop size distribution data, the raindrop spectral distribution parameters, and the preset attenuation efficiency factor parameters, the raindrop collective extinction coefficient corresponding to the target observation area within the preset sampling period is determined; Based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters, the visibility value corresponding to the target observation area within the preset sampling period is determined.

[0006] Furthermore, the raindrop size distribution data includes at least multiple raindrop size values ​​and the quantity distribution data corresponding to each raindrop size value; the step of acquiring the raindrop size distribution data collected within a preset sampling period for the target observation area where rainfall occurs includes: For the target observation area where rainfall occurs, a preset observation device is used to collect multiple first unprocessed raindrop particle size values ​​corresponding to raindrops in the target observation area within a preset sampling period, as well as the first unprocessed quantity distribution data corresponding to each first unprocessed raindrop particle size value; The sliding window method is used to remove outliers from the first raindrop particle size value and the first quantity distribution data to be processed, so as to obtain the second raindrop particle size value and the second quantity distribution data to be processed. The physical threshold method is used to remove outliers from the second raindrop particle size value and the second quantity distribution data to be processed, so as to obtain the third raindrop particle size value and the third quantity distribution data to be processed. The third raindrop particle size value to be processed and the third quantity distribution data to be processed are subjected to noise removal and smoothing processing respectively to obtain multiple raindrop particle size values ​​corresponding to the target observation area within a preset sampling period, and the quantity distribution data corresponding to each raindrop particle size value.

[0007] Furthermore, the step of using a physical thresholding method to remove outliers from the second raindrop size value and the second quantity distribution data to obtain the third raindrop size value and the third quantity distribution data includes: Each of the second raindrop particle size values ​​to be processed is compared with a preset particle size threshold to obtain the comparison results; Based on the comparison results, the second raindrop particle size value to be processed that is greater than the preset particle size threshold is removed to obtain the third raindrop particle size value to be processed. The second quantity distribution data corresponding to the second raindrop particle size value to be processed is removed to obtain the third quantity distribution data to be processed.

[0008] Furthermore, the raindrop spectral distribution parameters include at least the spectral intercept coefficient, spectral shape parameter, and spectral width parameter; the step of determining the rainfall intensity value and raindrop spectral distribution parameters corresponding to the target observation area within the preset sampling period based on the raindrop size distribution data includes: The raindrop size distribution data is fitted with a preset raindrop spectral distribution function to determine the spectral intercept coefficient, spectral shape parameter, and spectral width parameter of the target observation area within the preset sampling period; Based on the spectral intercept coefficient, the spectral shape parameter, and the spectral width parameter, the rainfall intensity value corresponding to the target observation area within the preset sampling period is determined.

[0009] Furthermore, determining the raindrop population extinction coefficient for the target observation area within the preset sampling period based on the raindrop size distribution data, the raindrop spectral distribution parameters, and the preset attenuation efficiency factor parameters includes: Based on the preset attenuation efficiency factor parameter and the raindrop size distribution data, a physical model of the extinction coefficient of rainfall particles is established; wherein, the attenuation efficiency factor parameter is determined by solving the geometric optical limit of the scale parameter of the rainfall particles. Based on the raindrop spectral distribution parameters, the physical model of the extinction coefficient of the rainfall particles is solved to determine the raindrop population extinction coefficient of the target observation area within the preset sampling period.

[0010] Furthermore, determining the visibility value of the target observation area within the preset sampling period based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters includes: Determine whether the rainfall intensity value is greater than or equal to a preset rainfall intensity threshold; If the rainfall intensity value is greater than or equal to the preset rainfall intensity threshold, then based on the raindrop collective extinction coefficient, the visibility value corresponding to the target observation area within the preset sampling period is determined; Alternatively, based on the rainfall intensity value and the raindrop spectrum distribution parameters, the visibility value corresponding to the target observation area within the preset sampling period can be determined.

[0011] Furthermore, determining the visibility value of the target observation area within the preset sampling period based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters further includes: If the rainfall intensity value is less than the preset rainfall intensity threshold, then the preset target visibility value is determined as the visibility value of the target observation area within the preset sampling period.

[0012] This application embodiment also provides a device for determining visibility during rainy weather, the device comprising: The rainfall observation module is used to acquire raindrop size distribution data collected within a preset sampling period for the target observation area where rainfall occurs. The data processing module is used to determine the rainfall intensity value and raindrop spectral distribution parameters of the target observation area within the preset sampling period based on the raindrop size distribution data. The extinction coefficient calculation module is used to determine the raindrop population extinction coefficient of the target observation area within the preset sampling period based on the raindrop size distribution data, the raindrop spectral distribution parameters, and the preset attenuation efficiency factor parameters. The visibility calculation module is used to determine the visibility value of the target observation area within the preset sampling period based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters.

[0013] Furthermore, the raindrop size distribution data includes at least multiple raindrop size values ​​and the quantity distribution data corresponding to each raindrop size value; when the rainfall observation module is used to acquire raindrop size distribution data collected within a preset sampling period for a target observation area experiencing rainfall, the rainfall observation module is used to: For the target observation area where rainfall occurs, a preset observation device is used to collect multiple first unprocessed raindrop particle size values ​​corresponding to raindrops in the target observation area within a preset sampling period, as well as the first unprocessed quantity distribution data corresponding to each first unprocessed raindrop particle size value; The sliding window method is used to remove outliers from the first raindrop particle size value and the first quantity distribution data to be processed, so as to obtain the second raindrop particle size value and the second quantity distribution data to be processed. The physical threshold method is used to remove outliers from the second raindrop particle size value and the second quantity distribution data to be processed, so as to obtain the third raindrop particle size value and the third quantity distribution data to be processed. The third raindrop particle size value to be processed and the third quantity distribution data to be processed are subjected to noise removal and smoothing processing respectively to obtain multiple raindrop particle size values ​​corresponding to the target observation area within a preset sampling period, and the quantity distribution data corresponding to each raindrop particle size value.

[0014] Furthermore, when the rainfall observation module is used to remove outliers from the second raindrop size value and the second quantity distribution data to be processed using the physical threshold method, and obtain the third raindrop size value and the third quantity distribution data to be processed, the rainfall observation module is used to: Each of the second raindrop particle size values ​​to be processed is compared with a preset particle size threshold to obtain the comparison results; Based on the comparison results, the second raindrop particle size value to be processed that is greater than the preset particle size threshold is removed to obtain the third raindrop particle size value to be processed. The second quantity distribution data corresponding to the second raindrop particle size value to be processed is removed to obtain the third quantity distribution data to be processed.

[0015] Furthermore, the raindrop spectral distribution parameters include at least the spectral intercept coefficient, spectral shape parameter, and spectral width parameter; when the data processing module is used to determine the rainfall intensity value and raindrop spectral distribution parameters corresponding to the target observation area within the preset sampling period based on the raindrop size distribution data, the data processing module is used to: The raindrop size distribution data is fitted with a preset raindrop spectral distribution function to determine the spectral intercept coefficient, spectral shape parameter, and spectral width parameter of the target observation area within the preset sampling period; Based on the spectral intercept coefficient, the spectral shape parameter, and the spectral width parameter, the rainfall intensity value corresponding to the target observation area within the preset sampling period is determined.

[0016] Furthermore, when the extinction coefficient calculation module is used to determine the raindrop population extinction coefficient corresponding to the target observation area within the preset sampling period based on the raindrop size distribution data, the raindrop spectral distribution parameters, and the preset attenuation efficiency factor parameters, the extinction coefficient calculation module is used to: Based on the preset attenuation efficiency factor parameter and the raindrop size distribution data, a physical model of the extinction coefficient of rainfall particles is established; wherein, the attenuation efficiency factor parameter is determined by solving the geometric optical limit of the scale parameter of the rainfall particles. Based on the raindrop spectral distribution parameters, the physical model of the extinction coefficient of the rainfall particles is solved to determine the raindrop population extinction coefficient of the target observation area within the preset sampling period.

[0017] Furthermore, when the visibility calculation module is used to determine the visibility value of the target observation area within the preset sampling period based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters, the visibility calculation module is used to: Determine whether the rainfall intensity value is greater than or equal to a preset rainfall intensity threshold; If the rainfall intensity value is greater than or equal to the preset rainfall intensity threshold, then based on the raindrop collective extinction coefficient, the visibility value corresponding to the target observation area within the preset sampling period is determined; Alternatively, based on the rainfall intensity value and the raindrop spectrum distribution parameters, the visibility value corresponding to the target observation area within the preset sampling period can be determined.

[0018] Furthermore, when the visibility calculation module is used to determine the visibility value of the target observation area within the preset sampling period based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters, the visibility calculation module is also used to: If the rainfall intensity value is less than the preset rainfall intensity threshold, then the preset target visibility value is determined as the visibility value of the target observation area within the preset sampling period.

[0019] This application embodiment also provides an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus. When the machine-readable instructions are executed by the processor, the steps of the above-described method for determining visibility in rainy weather are performed.

[0020] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the method for determining visibility in rainy weather as described above.

[0021] The present application provides a method and apparatus for determining visibility during rainfall. The method includes: acquiring raindrop size distribution data collected within a preset sampling period for a target observation area experiencing rainfall; determining the rainfall intensity value and raindrop spectral distribution parameters corresponding to the target observation area within the preset sampling period based on the raindrop size distribution data; determining the raindrop collective extinction coefficient corresponding to the target observation area within the preset sampling period based on the raindrop size distribution data, the raindrop spectral distribution parameters, and a preset attenuation efficiency factor parameter; and determining the visibility value corresponding to the target observation area within the preset sampling period based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters.

[0022] Compared with existing methods such as empirical formulas, Mie scattering models, and ray-tracing-based particle optics models, this method acquires raindrop size distribution data of the target observation area during rainfall in real time within a preset sampling period. This allows for the determination of rainfall intensity and raindrop spectral distribution parameters in the target observation area. Based on physical models relating the raindrop spectral distribution parameters and rainfall intensity to the raindrop population extinction coefficient, the visibility value of the target observation area within the preset sampling period is calculated. This approach incorporates the physical process of particle scattering into the theoretical model and adapts to different precipitation types and climatic conditions, improving the adaptability and real-time performance of visibility calculation during rainfall, thereby enhancing the accuracy and efficiency of visibility calculation during rainfall.

[0023] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A flowchart illustrating a method for determining visibility during rainfall, provided in an embodiment of this application; Figure 2 A schematic diagram of a device for determining visibility in rainy weather provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this application.

[0027] Research has shown that visibility is one of the most important meteorological indicators in many fields, including aviation, navigation, and road traffic. It directly affects travel safety and operational efficiency. Under severe weather conditions, such as heavy rain, thunderstorms, and sleet, rain particles can significantly scatter and absorb light waves, leading to a decrease in atmospheric transmittance and thus reducing horizontal visibility. Traditional visibility observation methods mainly rely on manual visual observation or automatic visibility meters (such as transmission and forward-scattering instruments). However, these devices may have problems such as large observation errors, high costs, and maintenance difficulties under heavy rainfall conditions.

[0028] Currently, the main methods for calculating visibility during rainy weather include empirical formulas, Mie scattering models, and particle optics models based on ray tracing.

[0029] Among them, the empirical formula method mainly uses the WMO recommended formula to correlate visibility and rainfall intensity through an empirical power function. An example of the expression of the WMO recommended formula is shown below.

[0030] .

[0031] here, Indicates visibility; Indicates rainfall intensity; and This represents an empirical coefficient. Although the empirical formula method is simple to calculate and easy to implement, it ignores the influence of precipitation particle size and shape, and the accuracy of the calculation varies greatly in different regions and different precipitation types.

[0032] The Mie scattering model method uses Mie scattering theory to calculate the scattering cross section and extinction coefficient of spherical raindrops, and combines the measured particle size distribution to invert visibility. However, this method is only applicable to spherical water droplets and has poor adaptability to non-spherical particles (e.g., ice crystals and graupel). It also has a large computational load and is not conducive to real-time operations.

[0033] The ray-tracing-based particle optical modeling method uses sophisticated geometric optical modeling to calculate the scattering characteristics of particles such as ellipsoidal raindrops, hexagonal ice crystals, and columnar ice crystals, obtaining the scattering phase function and extinction cross section. Although this method can accurately describe the optical characteristics of large particles and non-spherical particles, the computational load is large, making it difficult to apply directly in real time in specific scenarios.

[0034] In summary, the methods described above simply correlate rainfall intensity with visibility, neglecting the true optical scattering characteristics of precipitation particles and the influence of particle size distribution on extinction. This leads to significant deviations in calculation results under different rainfall patterns and raindrop size distributions. Some methods rely on historical statistical models or post-hoc recalculations, which cannot meet the needs of real-time visibility updates. Existing fixed-coefficient or empirical parameterization methods have poor applicability in different climate zones and different precipitation forms (e.g., liquid raindrops, solid ice crystals, and mixed-phase precipitation), reducing the adaptability and real-time performance of visibility calculations during rainfall, and consequently reducing the accuracy and efficiency of visibility calculations during rainfall.

[0035] Based on this, this application provides a method for determining visibility during rainfall. By acquiring raindrop size distribution data of a target observation area during a preset sampling period in real time, the rainfall intensity and raindrop spectral distribution parameters of the target observation area are determined. Based on the physical model between the raindrop spectral distribution parameters and rainfall intensity values ​​and the raindrop population extinction coefficient, the visibility value of the target observation area during the preset sampling period is calculated. This method considers the physical process of particle scattering in the theoretical model and adapts to different precipitation types and climatic conditions, improving the adaptability and real-time performance of visibility calculation during rainfall, thereby improving the accuracy and efficiency of visibility calculation during rainfall.

[0036] Please see Figure 1 , Figure 1 This is a flowchart illustrating a method for determining visibility during rainfall, provided as an embodiment of this application. Figure 1 As shown in the embodiments of this application, the method for determining visibility during rainy weather includes: S101. Obtain the raindrop size distribution data collected within a preset sampling period for the target observation area where rainfall occurs.

[0037] In this application embodiment, the preset sampling period can generally be set to 60 seconds; in rainstorms or rapidly changing weather, the preset sampling period can be set to 30 seconds or 10 seconds to obtain higher time resolution; for applications with higher real-time requirements, the preset sampling period can be set to less than or equal to 10 seconds.

[0038] The raindrop size distribution data includes at least multiple raindrop size values ​​and quantity distribution data corresponding to each raindrop size value.

[0039] In the embodiments of this application, the raindrop size distribution data may include a Gamma distribution. The Gamma distribution can fit the measured raindrop size spectrum of different rainfall types (e.g., convective rain, stratiform rain, and rainstorms). Compared with other functional forms such as the log-normal distribution, the Gamma distribution not only has a clear physical meaning (the size distribution characteristics are jointly controlled by intercept, shape, and spectral width parameters), but is also mathematically easier to integrate analytically. It can be directly combined with the extinction coefficient formula, which significantly simplifies the visibility calculation process. Therefore, the Gamma distribution can be used as the mainstream model for describing raindrop size spectrum in the meteorological and hydrological fields.

[0040] Here, raindrop size distribution data can also be described using log-normal distribution, exponential distribution, Weibull distribution, etc.

[0041] The raindrop size distribution data includes a size distribution histogram. For example, the size gradation width is generally 0.1 mm, covering a range of 0.18 mm.

[0042] In one possible implementation of this application, step S101 may include: S1011. For the target observation area where rainfall occurs, a preset observation device is used to collect multiple first unprocessed raindrop particle size values ​​corresponding to raindrops in the target observation area within a preset sampling period, as well as the first unprocessed quantity distribution data corresponding to each first unprocessed raindrop particle size value.

[0043] In the embodiments of this application, the observation equipment includes, but is not limited to, tipping bucket rain gauges, weighing rain gauges, optical raindrop spectrometers, dual-polarization weather radars, and microwave link monitoring equipment.

[0044] Specifically, tipping bucket or weighing rain gauges should be deployed in the target observation area, ensuring that the installation height is greater than or equal to the preset height value and away from obstacles such as buildings and trees to avoid wind obstruction affecting rainfall collection; optical rain spectrometers such as Parsivel and OTT can be used, with their beams perpendicular to the precipitation direction, and the installation position must be kept horizontal and stable to prevent vibration from interfering with the measurement; if it is difficult to deploy an optical rain spectrometer, raindrop spectrum information can be retrieved using regional dual-polarization weather radar or communication microwave links.

[0045] Furthermore, when it is impossible to collect multiple first-to-be-processed raindrop particle size values ​​and the first-to-be-processed quantity distribution data corresponding to each first-to-be-processed raindrop particle size value through an optical raindrop spectrometer, the first-to-be-processed raindrop particle size value and the first-to-be-processed quantity distribution data are determined based on historical meteorological statistical data.

[0046] S1012. Use the sliding window method to remove outliers from the first raindrop particle size value and the first quantity distribution data to be processed, and obtain the second raindrop particle size value and the second quantity distribution data to be processed.

[0047] For example, in the sliding window method, 3 to 5 sampling periods are set as windows, and the mean and standard deviation of the first raindrop particle size value to be processed and the first quantity distribution data to be processed are calculated respectively, and data that deviate from the mean within the preset error range are marked as abnormal.

[0048] S1013. Use the physical threshold method to remove outliers from the second raindrop particle size value and the second quantity distribution data to obtain the third raindrop particle size value and the third quantity distribution data to be processed.

[0049] In one possible implementation of this application, step S1013 may include: S10131. Compare the particle size value of each second raindrop to be processed with a preset particle size threshold to obtain the comparison result.

[0050] In this embodiment of the application, the preset particle size threshold can be set to 8 mm to prevent interference from the observation of objects such as insects and debris.

[0051] S10132. Based on the comparison result, the second raindrop particle size value to be processed that is greater than the preset particle size threshold is removed to obtain the third raindrop particle size value to be processed.

[0052] S10133. Remove the second quantity distribution data corresponding to the second raindrop particle size value to be processed, and obtain the third quantity distribution data to be processed.

[0053] S1014. The third raindrop particle size value to be processed and the third quantity distribution data to be processed are subjected to noise removal and smoothing processing respectively to obtain multiple raindrop particle size values ​​corresponding to the target observation area within a preset sampling period, and the quantity distribution data corresponding to each raindrop particle size value.

[0054] In this embodiment, median filtering is used to eliminate spike noise in the third raindrop size value and the third quantity distribution data to be processed; the third quantity distribution data to be processed is filtered and smoothed (e.g., Savitzky-Golay filtering and smoothing) to reduce the impact of noise while preserving the spectral characteristics.

[0055] S102. Based on the raindrop size distribution data, determine the rainfall intensity value and raindrop spectrum distribution parameters corresponding to the target observation area within the preset sampling period.

[0056] In this embodiment of the application, the raindrop spectral distribution parameters include at least the spectral intercept coefficient, the spectral shape parameter, and the spectral width parameter.

[0057] In one possible implementation of this application, step S102 may include: S1021. Using a preset raindrop spectral distribution function, perform parameter fitting on the raindrop particle size distribution data to determine the spectral intercept coefficient, spectral shape parameter, and spectral width parameter corresponding to the target observation area within the preset sampling period.

[0058] In this embodiment of the application, the expression of the preset raindrop spectrum distribution function is as follows.

[0059] .

[0060] in, Raindrop number density (in m³) represents the number of raindrops with a diameter of D. -3 mm -1 ); This indicates the raindrop size (in mm). Represents the spectral intercept coefficient (unit: mm) -1-m ·m -3 ); Indicates spectral parameters (dimensionless); Indicates spectral width parameter (unit: mm) -1 ).

[0061] In this step, the raindrop size distribution data is fitted using methods such as least squares or maximum likelihood estimation. The goodness of fit can be evaluated using R2 or chi-square test. If it is lower than a set threshold (e.g., R2 < 0.85), the most recent effective parameters are used to replace them to determine the spectral intercept coefficient, spectral shape parameter, and spectral width parameter of the target observation area within the preset sampling period.

[0062] S1022. Based on the spectral intercept coefficient, the spectral shape parameter, and the spectral width parameter, determine the rainfall intensity value corresponding to the target observation area within the preset sampling period.

[0063] In this embodiment of the application, the rainfall intensity value is determined by the following formula.

[0064] .

[0065] in, Indicates the rainfall intensity value; Indicates the spectral intercept coefficient; Indicates spectral shape parameters; Indicates the spectral width parameter; This represents the preset gamma function.

[0066] Here, when the rainfall intensity value is greater than the preset risk intensity threshold (e.g., 500 mm·h), -1 The target observation area is identified as an abnormal area.

[0067] S103. Based on the raindrop size distribution data, the raindrop spectral distribution parameters, and the preset attenuation efficiency factor parameters, determine the raindrop collective extinction coefficient corresponding to the target observation area within the preset sampling period.

[0068] The raindrop collective extinction coefficient is a physical quantity that describes the atmosphere's ability to attenuate the light emitted by a raindrop collective.

[0069] Here, the raindrop size is typically greater than 10 μm, much larger than the wavelength of visible light (e.g., 0.38-0.78 μm). The scale parameter of raindrops is large. Under these conditions, the traditional Mie scattering formula suffers from low computational efficiency and insufficient accuracy for large particles. Therefore, the geometrical optics approximation is usually used to describe the propagation process of light in non-spherical particles such as large water droplets and ice crystals. By combining raindrop spectral distribution data, a physical relationship between the extinction coefficient and rainfall intensity can be established. Furthermore, the relationship between visibility and atmospheric extinction coefficient, which is used in meteorology, can be used to calculate visibility.

[0070] Thus, the embodiments of this application do not depend on the phase of precipitation. For solid precipitation, the extinction coefficient of the raindrop population can be calculated by adjusting the raindrop size distribution data and refractive index parameters. Under mixed precipitation conditions (such as rain and snow), the extinction coefficient can be calculated separately for each phase and then weighted and superimposed, which significantly improves the adaptability of visibility estimation.

[0071] In one possible implementation of this application, step S103 may include: S1031. Based on the preset attenuation efficiency factor parameters and the raindrop particle size distribution data, establish a physical model of the extinction coefficient of rainfall particles.

[0072] The attenuation efficiency factor parameter is determined by solving the geometrical optical limit of the scale parameters of the rainfall particles.

[0073] In the embodiments of this application, for rain particles with a particle size greater than 10 μm (e.g., raindrops, snowflakes, and ice particles), the scale parameter of the rain particles is much larger than the scattering limit under visible light wavelength. Under large-scale parameter conditions, the geometrical optics limit can be directly used to approximate the solution, and the attenuation efficiency factor parameter is determined to be close to 2. That is, the attenuation efficiency factor parameter described in the embodiments of this application is generally set to 2.

[0074] For example, when the raindrop size is greater than 10 μm, the scale parameter (x = πD / λ, where λ is the refractive index parameter of the raindrop) is much greater than 100, and the attenuation efficiency factor of various raindrop particles approaches 2. Therefore, 2 can be used as the preset attenuation efficiency factor parameter.

[0075] In this embodiment of the application, the expression of the physical model for the extinction coefficient of rainfall particles is as follows.

[0076] .

[0077] in, Indicates the collective extinction coefficient of raindrops; This represents the attenuation efficiency factor parameter; Indicates the raindrop size value; Indicates the spectral intercept coefficient; Indicates spectral shape parameters; Indicates the spectral width parameter; Here is the refractive index parameter of the raindrop.

[0078] S1032. Based on the raindrop spectral distribution parameters, solve the physical model of the extinction coefficient of the rainfall particles to determine the raindrop population extinction coefficient of the target observation area within the preset sampling period.

[0079] In this embodiment of the application, the expression obtained by solving the physical model of the extinction coefficient of rainfall particles is shown below.

[0080] .

[0081] in, Indicates the collective extinction coefficient of raindrops; Indicates the spectral intercept coefficient; Indicates spectral shape parameters; Indicates the spectral width parameter; This represents the preset gamma function.

[0082] S104. Based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters, determine the visibility value corresponding to the target observation area within the preset sampling period.

[0083] Here, the visibility value represents the maximum horizontal distance at which the observed object can be clearly identified under atmospheric conditions.

[0084] In this embodiment, the visibility value of the target observation area within a preset sampling period can be applied to at least traffic management systems, aviation meteorological systems, ship navigation systems, and public weather warning platforms.

[0085] For example, in traffic management systems, when visibility is less than 500 m, dynamic speed limit signs on highways can be automatically triggered, and road condition warnings can be sent to vehicle terminals when visibility drops sharply; in aviation meteorological systems, visibility values ​​can be sent to airport tower meteorological workstations to assist in flight take-off and landing feasibility assessments and support the synchronous display of runway visual range (RVR) and visibility; in ship navigation systems, real-time visibility information can be broadcast through shipborne AIS systems for reference by ships in the waterway to avoid obstacles; in public weather warning platforms, visibility warnings can be issued and predictions of future visibility trends can be provided.

[0086] Furthermore, in situations where fog, dust, haze, and precipitation coexist, visibility values ​​can be fused with observations from aerosol lidar, visibility meters, and other sources to separate precipitation and non-precipitation extinction components, thereby maintaining the reliability of the calculation results.

[0087] In one possible implementation of this application, step S104 may include: S1041. Determine whether the rainfall intensity value is greater than or equal to a preset rainfall intensity threshold.

[0088] In this embodiment of the application, the preset rainfall intensity threshold can generally be set to 0.1 mm·h. -1 .

[0089] S1042. If the rainfall intensity value is greater than or equal to the preset rainfall intensity threshold, then based on the raindrop extinction coefficient, determine the visibility value corresponding to the target observation area within the preset sampling period.

[0090] In this embodiment of the application, the visibility value is determined based on the extinction coefficient of the raindrop population using the following formula.

[0091] .

[0092] in, This indicates the visibility value (in km). This represents the extinction coefficient of the raindrop population.

[0093] S1043, or, based on the rainfall intensity value and the raindrop spectrum distribution parameters, determine the visibility value corresponding to the target observation area within the preset sampling period.

[0094] In this embodiment of the application, the visibility value is determined based on the rainfall intensity value and the raindrop spectrum distribution parameters using the following formula.

[0095] .

[0096] in, This indicates the visibility value (in km). Indicates the rainfall intensity value; Indicates spectral shape parameters; Indicates the spectral width parameter; This represents the preset gamma function.

[0097] In one possible implementation of this application, step S104 further includes: S1044. If the rainfall intensity value is less than the preset rainfall intensity threshold, then the preset target visibility value is determined as the visibility value of the target observation area within the preset sampling period.

[0098] For example, when the rainfall intensity is less than 0.1 mm·h -1 At that time, the preset target visibility value can be directly determined as the visibility value corresponding to the target observation area within the preset sampling period.

[0099] The preset target visibility value is the maximum visibility value set in advance, and the target visibility value is generally set in a range greater than 20km.

[0100] The method for determining visibility during rainfall provided in this application acquires raindrop size distribution data of the target observation area during a preset sampling period in real time, thereby determining the rainfall intensity and raindrop spectral distribution parameters of the target observation area. Based on the physical model between the raindrop spectral distribution parameters and rainfall intensity and the raindrop population extinction coefficient, the visibility value of the target observation area during the preset sampling period is calculated. This method considers the physical process of particle scattering in the theoretical model and adapts to different precipitation types and climatic conditions, improving the adaptability and real-time performance of visibility calculation during rainfall, and thus improving the accuracy and efficiency of visibility calculation during rainfall.

[0101] Please see Figure 2 , Figure 2 This is a schematic diagram of a device for determining visibility in rainy weather, provided as an embodiment of this application. Figure 2 As shown, the determining device 200 includes: Rainfall observation module 210 is used to acquire raindrop size distribution data collected within a preset sampling period for the target observation area where rainfall occurs. Data processing module 220 is used to determine the rainfall intensity value and raindrop spectral distribution parameters of the target observation area within the preset sampling period based on the raindrop size distribution data. The extinction coefficient calculation module 230 is used to determine the raindrop population extinction coefficient of the target observation area within the preset sampling period based on the raindrop size distribution data, the raindrop spectral distribution parameters and the preset attenuation efficiency factor parameters. The visibility calculation module 240 is used to determine the visibility value of the target observation area within the preset sampling period based on the rainfall intensity value, the raindrop collective extinction coefficient and the raindrop spectral distribution parameters.

[0102] Furthermore, the raindrop size distribution data includes at least multiple raindrop size values ​​and the quantity distribution data corresponding to each raindrop size value; when the rainfall observation module 210 is used to acquire the raindrop size distribution data collected within a preset sampling period for a target observation area experiencing rainfall, the rainfall observation module 210 is used for: For the target observation area where rainfall occurs, a preset observation device is used to collect multiple first unprocessed raindrop particle size values ​​corresponding to raindrops in the target observation area within a preset sampling period, as well as the first unprocessed quantity distribution data corresponding to each first unprocessed raindrop particle size value; The sliding window method is used to remove outliers from the first raindrop particle size value and the first quantity distribution data to be processed, so as to obtain the second raindrop particle size value and the second quantity distribution data to be processed. The physical threshold method is used to remove outliers from the second raindrop particle size value and the second quantity distribution data to be processed, so as to obtain the third raindrop particle size value and the third quantity distribution data to be processed. The third raindrop particle size value to be processed and the third quantity distribution data to be processed are subjected to noise removal and smoothing processing respectively to obtain multiple raindrop particle size values ​​corresponding to the target observation area within a preset sampling period, and the quantity distribution data corresponding to each raindrop particle size value.

[0103] Furthermore, when the rainfall observation module 210 is used to remove outliers from the second raindrop particle size value and the second raindrop quantity distribution data using the physical threshold method to obtain the third raindrop particle size value and the third raindrop quantity distribution data, the rainfall observation module 210 is used to: Each of the second raindrop particle size values ​​to be processed is compared with a preset particle size threshold to obtain the comparison results; Based on the comparison results, the second raindrop particle size value to be processed that is greater than the preset particle size threshold is removed to obtain the third raindrop particle size value to be processed. The second quantity distribution data corresponding to the second raindrop particle size value to be processed is removed to obtain the third quantity distribution data to be processed.

[0104] Furthermore, the raindrop spectral distribution parameters include at least the spectral intercept coefficient, spectral shape parameter, and spectral width parameter; when the data processing module 220 determines the rainfall intensity value and raindrop spectral distribution parameters corresponding to the target observation area within the preset sampling period based on the raindrop size distribution data, the data processing module 220 is used to: The raindrop size distribution data is fitted with a preset raindrop spectral distribution function to determine the spectral intercept coefficient, spectral shape parameter, and spectral width parameter of the target observation area within the preset sampling period; Based on the spectral intercept coefficient, the spectral shape parameter, and the spectral width parameter, the rainfall intensity value corresponding to the target observation area within the preset sampling period is determined.

[0105] Furthermore, when the extinction coefficient calculation module 230 is used to determine the raindrop population extinction coefficient of the target observation area within the preset sampling period based on the raindrop size distribution data, the raindrop spectral distribution parameters, and the preset attenuation efficiency factor parameters, the extinction coefficient calculation module 230 is used to: Based on the preset attenuation efficiency factor parameter and the raindrop size distribution data, a physical model of the extinction coefficient of rainfall particles is established; wherein, the attenuation efficiency factor parameter is determined by solving the geometric optical limit of the scale parameter of the rainfall particles. Based on the raindrop spectral distribution parameters, the physical model of the extinction coefficient of the rainfall particles is solved to determine the raindrop population extinction coefficient of the target observation area within the preset sampling period.

[0106] Furthermore, when the visibility calculation module 240 is used to determine the visibility value of the target observation area within the preset sampling period based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters, the visibility calculation module 240 is used to: Determine whether the rainfall intensity value is greater than or equal to a preset rainfall intensity threshold; If the rainfall intensity value is greater than or equal to the preset rainfall intensity threshold, then based on the raindrop collective extinction coefficient, the visibility value corresponding to the target observation area within the preset sampling period is determined; Alternatively, based on the rainfall intensity value and the raindrop spectrum distribution parameters, the visibility value corresponding to the target observation area within the preset sampling period can be determined.

[0107] Furthermore, when the visibility calculation module 240 is used to determine the visibility value of the target observation area within the preset sampling period based on the rainfall intensity value, the raindrop collective extinction coefficient, and the raindrop spectral distribution parameters, the visibility calculation module 240 is also used to: If the rainfall intensity value is less than the preset rainfall intensity threshold, then the preset target visibility value is determined as the visibility value of the target observation area within the preset sampling period.

[0108] The visibility determination device for rainy weather provided in this application acquires raindrop size distribution data of the target observation area during a preset sampling period in real time, thereby determining the rainfall intensity and raindrop spectral distribution parameters of the target observation area. Based on the physical model between the raindrop spectral distribution parameters and rainfall intensity and the raindrop population extinction coefficient, the visibility value of the target observation area during the preset sampling period is calculated. This device considers the physical process of particle scattering in the theoretical model and adapts to different precipitation types and climatic conditions, improving the adaptability and real-time performance of visibility calculation during rainy weather, and thus improving the accuracy and efficiency of visibility calculation during rainy weather.

[0109] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 3 As shown, the electronic device 300 includes a processor 310, a memory 320, and a bus 330.

[0110] The memory 320 stores machine-readable instructions executable by the processor 310. When the electronic device 300 is running, the processor 310 and the memory 320 communicate via the bus 330. When the machine-readable instructions are executed by the processor 310, they can perform the operations described above. Figure 1 The steps of the method for determining visibility during rainfall in the illustrated method embodiment can be found in the method embodiment for specific implementation methods, which will not be repeated here.

[0111] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, can perform the above-described actions. Figure 1 The steps of the method for determining visibility during rainfall in the illustrated method embodiment can be found in the method embodiment for specific implementation methods, which will not be repeated here.

[0112] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0113] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0114] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0115] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0116] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0117] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method of determining rainfall weather visibility, characterized in that, The determination method comprises: acquiring raindrop particle size distribution data corresponding to the target observation area in a preset sampling period when it rains; based on the raindrop particle size distribution data, the raindrop spectrum distribution parameters and the preset attenuation efficiency factor parameters, determining the raindrop group extinction coefficient of the target observation area in the preset sampling period; based on the raindrop particle size distribution data, the raindrop spectrum distribution parameters and the preset attenuation efficiency factor parameters, determining the raindrop group extinction coefficient of the target observation area in the preset sampling period; based on the raindrop particle size distribution data, the raindrop spectrum distribution parameters and the preset attenuation efficiency factor parameters, determining the raindrop group extinction coefficient of the target observation area in the preset sampling period.

2. The method of claim 1, wherein, The raindrop particle size distribution data at least includes a plurality of raindrop particle size values and the corresponding number distribution data of each raindrop particle size value; the acquisition of the raindrop particle size distribution data corresponding to the target observation area in a preset sampling period when it rains comprises: for the target observation area when it rains, using a preset observation device to collect a plurality of first to-be-processed raindrop particle size values corresponding to the raindrop in the target observation area in a preset sampling period, and the first to-be-processed number distribution data corresponding to each first to-be-processed raindrop particle size value respectively; using a sliding window method to remove outliers from the first to-be-processed raindrop particle size values and the first to-be-processed number distribution data, to obtain second to-be-processed raindrop particle size values and second to-be-processed number distribution data; using a physical threshold method to remove outliers from the second to-be-processed raindrop particle size values and the second to-be-processed number distribution data, to obtain third to-be-processed raindrop particle size values and third to-be-processed number distribution data; performing noise removal and smoothing processing on the third to-be-processed raindrop particle size values and the third to-be-processed number distribution data respectively, to obtain a plurality of raindrop particle size values corresponding to the target observation area in a preset sampling period, and the number distribution data corresponding to each raindrop particle size value respectively.

3. The method of claim 2, wherein, The use of a physical threshold method to remove outliers from the second to-be-processed raindrop particle size values and the second to-be-processed number distribution data, to obtain third to-be-processed raindrop particle size values and third to-be-processed number distribution data, comprises: comparing each second to-be-processed raindrop particle size value with a preset particle size threshold to obtain a comparison result; based on the comparison result, removing the second to-be-processed raindrop particle size values greater than the preset particle size threshold to obtain third to-be-processed raindrop particle size values; removing the second to-be-processed number distribution data corresponding to the removed second to-be-processed raindrop particle size values to obtain third to-be-processed number distribution data.

4. The method of claim 1, wherein, The raindrop spectrum distribution parameters at least include a spectrum intercept coefficient, a spectrum shape parameter and a spectrum width parameter; the determination of the raindrop spectrum distribution parameters of the target observation area in the preset sampling period based on the raindrop particle size distribution data comprises: The raindrop size distribution data is parameter fitted by using a preset raindrop spectrum distribution function, to determine the spectrum intercept coefficient, the spectrum shape parameter and the spectrum width parameter corresponding to the target observation area in the preset sampling period; Based on the spectrum intercept coefficient, the spectrum shape parameter and the spectrum width parameter, the rainfall intensity value corresponding to the target observation area in the preset sampling period is determined.

5. The method of claim 1, wherein, The raindrop group extinction coefficient corresponding to the target observation area in the preset sampling period is determined based on the raindrop size distribution data, the raindrop spectrum distribution parameter and a preset attenuation efficiency factor parameter, including: A rainfall particle extinction coefficient physical model is established based on the preset attenuation efficiency factor parameter and the raindrop size distribution data, wherein the attenuation efficiency factor parameter is determined by solving the geometric optics limit of the scale parameter of the rainfall particle; The raindrop group extinction coefficient corresponding to the target observation area in the preset sampling period is determined by solving the rainfall particle extinction coefficient physical model based on the raindrop spectrum distribution parameter.

6. The method of claim 1, wherein, The visibility value corresponding to the target observation area in the preset sampling period is determined based on the rainfall intensity value, the raindrop group extinction coefficient and the raindrop spectrum distribution parameter, including: It is judged whether the rainfall intensity value is greater than or equal to a preset rainfall intensity threshold value; If the rainfall intensity value is greater than or equal to the preset rainfall intensity threshold value, the visibility value corresponding to the target observation area in the preset sampling period is determined based on the raindrop group extinction coefficient; Or, the visibility value corresponding to the target observation area in the preset sampling period is determined based on the rainfall intensity value and the raindrop spectrum distribution parameter.

7. The method of claim 6, wherein, The visibility value corresponding to the target observation area in the preset sampling period is determined based on the rainfall intensity value, the raindrop group extinction coefficient and the raindrop spectrum distribution parameter, further including: If the rainfall intensity value is less than the preset rainfall intensity threshold value, a preset target visibility value is determined as the visibility value corresponding to the target observation area in the preset sampling period.

8. A device for determining the visibility in rain weather, characterized in that The determination device includes: A rainfall observation module is configured to acquire raindrop size distribution data collected in a preset sampling period for a target observation area in which rainfall occurs; A data processing module is configured to determine a rainfall intensity value and a raindrop spectrum distribution parameter corresponding to the target observation area in the preset sampling period based on the raindrop size distribution data, respectively; An extinction coefficient calculation module is configured to determine a raindrop group extinction coefficient corresponding to the target observation area in the preset sampling period based on the raindrop size distribution data, the raindrop spectrum distribution parameter and a preset attenuation efficiency factor parameter; A visibility calculation module is configured to determine a visibility value corresponding to the target observation area in the preset sampling period based on the rainfall intensity value, the raindrop group extinction coefficient and the raindrop spectrum distribution parameter.

9. An electronic device, comprising: including: A processor, a memory and a bus, the memory stores machine readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, the machine readable instructions are executed by the processor to perform the steps of the method for determining rain weather visibility according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, A computer readable storage medium stores a computer program, the computer program is executed by the processor to perform the steps of the method for determining rain weather visibility according to any one of claims 1 to 7.

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