A clear air echo-based weather radar reflectivity factor calibration method

Abstract

The embodiment of the present disclosure provides a weather radar reflectivity factor calibration method based on clear air echo, comprising: obtaining reflectivity factor data obtained by standard weather radar and to-be-measured weather radar for synchronous observation on the same clear air area; wherein the standard weather radar is a normal performance weather radar, and works at a first wavelength; the to-be-measured weather radar is a weather radar with questionable performance, and works at a second wavelength; clear air echo reflectivity factor data is selected from the reflectivity factor data, and the measured dual-wavelength ratio is calculated therefrom; the theoretical dual-wavelength ratio is calculated according to the first wavelength and the second wavelength; if the measured dual-wavelength ratio and the theoretical dual-wavelength ratio are not equal, then the reflectivity factor data observed by the to-be-measured weather radar is calibrated according to the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio. In this way, remote and automatic weather radar reflectivity factor calibration can be realized based on clear air echo, without the need for additional personnel to go to the operation.

Description

Technical Field

[0001] This disclosure relates to the field of meteorological detection technology, and in particular to a method for calibrating the reflectivity factor of meteorological radar based on clear-sky echoes. Background Technology

[0002] Currently, radar equipment of various frequency bands is widely used in meteorology. However, due to differences in the technical specifications, maintenance conditions, and installation environments of different meteorological equipment, a significant number of meteorological radars exhibit varying deviations in their core product—the reflectivity factor. Limited by labor costs, transportation, and environmental constraints, it is necessary to propose a long-distance calibration method based on other remote sensing equipment.

[0003] Current radar reflectivity factor calibration methods mostly involve in-system calibration or field calibration, which involves sending personnel to the site to measure the internal circuitry of the equipment or using other equipment. Alternatively, light rain can be used to analyze the echo distribution observed by different radars, allowing for the calibration of other weather radars using one as a benchmark. However, these in-system or field calibration methods require personnel deployment, are time-consuming and labor-intensive, and have long cycles. Furthermore, methods based on precipitation target deviation comparisons are prone to introducing systemic biases due to different scattering effects of different wavebands on the same precipitation particles, and are difficult to assess before precipitation occurs, affecting flood season monitoring. Summary of the Invention

[0004] In a first aspect, embodiments of this disclosure provide a method for calibrating the reflectivity factor of a weather radar based on clear-sky echoes, the method comprising: Reflectivity factor data were obtained from synchronous observations of the same clear-sky area by a standard weather radar and a weather radar under test; the standard weather radar was a weather radar with normal performance and operated at the first wavelength, while the weather radar under test was a weather radar with questionable performance and operated at the second wavelength. The reflectivity factor data of clear sky echoes observed by the standard weather radar and the weather radar under test were selected from the reflectivity factor data observed by the standard weather radar and the weather radar under test. The measured dual-wavelength ratio is calculated based on the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test; the theoretical dual-wavelength ratio is calculated based on the first wavelength and the second wavelength. If the measured dual-wavelength ratio and the theoretical dual-wavelength ratio are not equal, the weather radar under test is determined to be malfunctioning. The reflectivity factor data observed by the weather radar under test is then calibrated based on the deviation between the measured and theoretical dual-wavelength ratios.

[0005] Among some feasible methods of the first aspect, the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test are selected from the reflectivity factor data observed by the standard weather radar and the weather radar under test, including: Quality control is performed on reflectivity factor data observed by standard weather radar and weather radar under test; Based on the screening criteria, clear-sky echo reflectance factor data observed by standard weather radar and weather radar under test were selected from the reflectance factor data after quality control.

[0006] Among some possible implementations of the first aspect, quality control includes: ground clutter removal, noise suppression, and outlier handling; screening criteria include: clear-sky echo reflectivity factor threshold, clear-sky echo area spatial texture features, and clear-sky echo area temporal continuity features.

[0007] In some feasible ways of implementing the first aspect, the measured dual-wavelength ratio is calculated based on clear-sky echo reflectivity factor data observed by a standard weather radar and the weather radar under test, including: Based on the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test, the measured dual-wavelength ratio is calculated using the following formula: ; in, Indicates the measured dual-wavelength ratio; This represents the clear-sky echo reflectivity factor data observed by standard weather radar; This represents the clear-sky echo reflectivity factor data observed by the weather radar under test.

[0008] Among some implementable methods of the first aspect, the theoretical dual-wavelength ratio is calculated based on the first wavelength and the second wavelength, including: The theoretical dual-wavelength ratio is calculated using the following formula based on the first and second wavelengths: ; in, Indicates the theoretical two-wavelength ratio; Indicates the first wavelength; This indicates the second wavelength.

[0009] In some feasible implementations of the first aspect, the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio is calculated using the following formula: ; in, This indicates the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio; Indicates the measured dual-wavelength ratio; This represents the theoretical two-wavelength ratio.

[0010] In some possible implementations of the first aspect, the combination of the first wavelength and the second wavelength is selected from any one of the S-band and C-band, the C-band and X-band, and the Ka-band and W-band.

[0011] Secondly, embodiments of this disclosure provide a weather radar reflectivity factor calibration device based on clear-sky echoes, the device comprising: The acquisition module is used to acquire reflectivity factor data obtained by synchronous observation of the same clear sky area by a standard weather radar and a weather radar under test; wherein, the standard weather radar is a weather radar with normal performance and operates at the first wavelength, and the weather radar under test is a weather radar with questionable performance and operates at the second wavelength. The filtering module is used to filter out clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test from the reflectivity factor data observed by the standard weather radar and the weather radar under test. The calculation module is used to calculate the measured dual-wavelength ratio based on the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test; and to calculate the theoretical dual-wavelength ratio based on the first wavelength and the second wavelength. The calibration module is used to determine that the weather radar under test is malfunctioning if the measured dual-wavelength ratio and the theoretical dual-wavelength ratio are not equal. The module calibrates the reflectivity factor data observed by the weather radar under test based on the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio.

[0012] Thirdly, embodiments of this disclosure provide an electronic device comprising: at least one processor; and a memory communicatively connected to the at least one processor; the memory storing instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method described above.

[0013] Fourthly, embodiments of this disclosure provide a non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the methods described above.

[0014] In this embodiment of the disclosure, remote and automated weather radar reflectivity factor calibration can be achieved based on clear-sky echoes, without the need to send additional personnel to operate it.

[0015] It should be understood that the description in the Summary of the Invention is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0016] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. The drawings are provided for a better understanding of the invention and are not intended to limit the scope of this disclosure. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein: Figure 1A flowchart of a weather radar reflectivity factor calibration method based on clear-sky echoes provided in an embodiment of this disclosure is shown; Figure 2 A structural diagram of a weather radar reflectivity factor calibration device based on clear-sky echoes provided in an embodiment of this disclosure is shown. Figure 3 A structural diagram of an exemplary electronic device capable of implementing embodiments of the present disclosure is shown. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0018] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0019] To address the problems in the background technology, this disclosure provides a method for calibrating the reflectivity factor of a weather radar based on clear-sky echoes. Specifically, reflectivity factor data are acquired by synchronous observations of the same clear-sky area by a standard weather radar and a weather radar under test. The standard weather radar is a normally functioning radar operating at the first wavelength, while the weather radar under test is a radar with questionable performance operating at the second wavelength. Clear-sky echo reflectivity factor data is selected from the reflectivity factor data, and the measured dual-wavelength ratio is calculated using this data. The theoretical dual-wavelength ratio is calculated based on the first and second wavelengths. If the measured dual-wavelength ratio and the theoretical dual-wavelength ratio are not equal, the reflectivity factor data observed by the weather radar under test is calibrated based on the deviation between the measured and theoretical dual-wavelength ratios. In this way, remote and automated weather radar reflectivity factor calibration can be achieved based on clear-sky echoes, eliminating the need for additional personnel to operate the system.

[0020] The following detailed description, with reference to the accompanying drawings, illustrates a meteorological radar reflectivity factor calibration method based on clear-sky echoes provided in this disclosure through specific embodiments.

[0021] Figure 1 A flowchart of a weather radar reflectivity factor calibration method based on clear-sky echoes provided in this disclosure is shown, as illustrated in the embodiment. Figure 1As shown, method 100 may include the following steps: S110: Acquire reflectivity factor data obtained from simultaneous observations of the same clear-sky area by a standard weather radar and a weather radar under test.

[0022] The standard weather radar is a normally functioning weather radar operating at the first wavelength, while the weather radar under test is a weather radar with questionable performance operating at the second wavelength. (First wavelength) The second wavelength can be selected from any combination of S-band and C-band, C-band and X-band, or Ka-band and W-band.

[0023] S120: Select clear-sky echo reflectance factor data from the reflectance factor data observed by the standard weather radar and the weather radar under test.

[0024] In some embodiments, the reflectivity factor data observed by the standard weather radar and the weather radar under test are subjected to quality control, and the clear sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test are selected from the quality-controlled reflectivity factor data according to the screening criteria.

[0025] Furthermore, quality control may include: ground clutter removal, noise suppression, outlier handling, etc.; screening criteria may include: clear sky echo reflectivity factor threshold, clear sky echo area spatial texture features, and clear sky echo area temporal continuity features, etc.

[0026] It's important to know that clear-sky echoes are echoes detected by scattering caused by atmospheric turbulence in clear, cloudless or sparsely clouded atmospheres. They are generally observable on nights from late spring / early summer to late autumn, and their scattering cross-section... It can be recorded as: ,in, Indicates the atmospheric refractive index structure constant; Indicates wavelength. For clear-sky echo identification, there are several methods: (1) The human eye observed no precipitation in the area near the weather radar, and there were weak echoes in terms of reflectivity.

[0027] (2) After nightfall, large-area echoes in the shape of a disc appear rapidly in the area below 3km altitude.

[0028] (3) The meteorological satellite did not detect the presence of clouds in the area of ​​the meteorological radar echo.

[0029] (4) No precipitation was observed in the area of ​​the weather radar echo by the ground automatic station.

[0030] S130: Calculate the measured dual-wavelength ratio based on the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test; calculate the theoretical dual-wavelength ratio based on the first wavelength and the second wavelength.

[0031] In some embodiments, the measured dual-wavelength ratio is calculated using the following formula based on clear-sky echo reflectivity factor data observed by a standard weather radar and the weather radar under test: ; in, Indicates the measured dual-wavelength ratio; This represents the clear-sky echo reflectivity factor data (logarithmic value) observed by standard weather radar. This represents the logarithmic data of clear-sky echo reflectivity factor observed by the weather radar under test.

[0032] In some embodiments, the theoretical dual-wavelength ratio is calculated using the following formula based on the first wavelength and the second wavelength: ; in, Indicates the theoretical two-wavelength ratio; Indicates the first wavelength; This indicates the second wavelength.

[0033] S140. If the measured dual-wavelength ratio and the theoretical dual-wavelength ratio are not equal, the weather radar under test is determined to be malfunctioning. The reflectivity factor data observed by the weather radar under test is calibrated based on the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio.

[0034] In some embodiments, the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio is calculated using the following formula: ; in, This represents the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio, expressed in dB, which is the deviation of the reflectivity factor of the weather radar under test. Indicates the measured dual-wavelength ratio; This represents the theoretical two-wavelength ratio.

[0035] Furthermore, the derivation of the deviation calculation formula can be shown below: ; ; ; The parameters involved here can be found in the aforementioned content and will not be repeated here.

[0036] For example, calibrating the reflectivity factor data observed by the weather radar under test here refers to adjusting the reflectivity factor data observed by the weather radar under test in the past, present, and future. Deviation compensation.

[0037] In summary, according to the embodiments of this disclosure, at least the following technical effects are achieved: (1) Realize unmanned and automated remote calibration: By comparing and analyzing the observation data of the same clear sky area using different meteorological radars, there is no need to send personnel to the meteorological radar site for in-flight or field calibration, which significantly saves manpower, material resources and time costs and improves calibration efficiency.

[0038] (2) Avoiding systematic biases introduced by differences in precipitation scattering: When traditional methods use precipitation targets such as light rain for calibration, the scattering effects of different band weather radars on the same precipitation particles may differ, leading to systematic errors. The embodiments of this disclosure use clear-sky echoes as calibration benchmarks, effectively avoiding the bias problems caused by different precipitation particle scattering characteristics, and improving the accuracy and reliability of calibration.

[0039] (3) Real-time or near-real-time calibration with flexible cycles: Since it does not depend on precipitation events, calibration can be performed under any clear sky conditions, breaking through the limitation that traditional schemes can only be implemented when precipitation occurs. It is especially beneficial to complete equipment performance evaluation and calibration in advance before the flood season or during key monitoring periods, ensuring the continuity and availability of monitoring data.

[0040] (4) Improve the objectivity and repeatability of calibration: By calculating the ratio of measured and theoretical dual wavelengths and performing performance judgment and calibration based on clear mathematical relationships, the influence of subjective factors is reduced, making the calibration process more standardized and traceable, which is conducive to maintaining the consistency of data among multiple meteorological radars.

[0041] (5) Support for performance monitoring and cross-verification of meteorological radars of different wavelengths: The embodiments of this disclosure explicitly involve the collaborative observation and comparison of meteorological radars of different wavelengths, which can not only be used to calibrate meteorological radars with questionable performance, but also provide technical support for the collaborative operation and data fusion of multi-band meteorological radar systems, thereby enhancing the robustness of the overall meteorological observation network.

[0042] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this disclosure is not limited to the described order of actions, because according to this disclosure, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this disclosure.

[0043] The above is an introduction to the method embodiments. The following describes the solution described in this disclosure further through device embodiments.

[0044] Figure 2 A structural diagram of a weather radar reflectivity factor calibration device based on clear-sky echoes provided in an embodiment of this disclosure is shown, as follows: Figure 2 As shown, the device 200 may include: The acquisition module 210 is used to acquire reflectivity factor data obtained by synchronous observation of the same clear sky area by a standard weather radar and a weather radar under test; wherein, the standard weather radar is a weather radar with normal performance and operates at the first wavelength, and the weather radar under test is a weather radar with questionable performance and operates at the second wavelength.

[0045] The filtering module 220 is used to filter out clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test from the reflectivity factor data observed by the standard weather radar and the weather radar under test.

[0046] The calculation module 230 is used to calculate the measured dual-wavelength ratio based on the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test; and to calculate the theoretical dual-wavelength ratio based on the first wavelength and the second wavelength.

[0047] The calibration module 240 is used to determine that the weather radar under test is malfunctioning if the measured dual-wavelength ratio and the theoretical dual-wavelength ratio are not equal, and to calibrate the reflectivity factor data observed by the weather radar under test based on the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio.

[0048] Understandable Figure 2 Each module / unit in the illustrated device 200 has the ability to implement Figure 1 The functions of each step in method 100 shown, and their corresponding technical effects, will not be elaborated here for the sake of brevity.

[0049] Figure 3 A structural diagram of an exemplary electronic device capable of implementing embodiments of the present disclosure is shown. Electronic device 300 is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic device 300 may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0050] like Figure 3As shown, the electronic device 300 may include a computing unit 301, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 302 or a computer program loaded from a storage unit 308 into a random access memory (RAM) 303. The RAM 303 may also store various programs and data required for the operation of the electronic device 300. The computing unit 301, ROM 302, and RAM 303 are interconnected via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0051] Multiple components in electronic device 300 are connected to I / O interface 305, including: input unit 306, such as keyboard, mouse, etc.; output unit 307, such as various types of displays, speakers, etc.; storage unit 308, such as disk, optical disk, etc.; and communication unit 309, such as network card, modem, wireless transceiver, etc. Communication unit 309 allows electronic device 300 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0052] The computing unit 301 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 301 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 301 performs the various methods and processes described above, such as method 100. For example, in some embodiments, method 100 may be implemented as a computer program product, including a computer program tangibly contained in a computer-readable medium, such as storage unit 308. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 300 via ROM 302 and / or communication unit 309. When the computer program is loaded into RAM 303 and executed by the computing unit 301, one or more steps of method 100 described above may be performed. Alternatively, in other embodiments, the computing unit 301 may be configured to perform method 100 by any other suitable means (e.g., by means of firmware).

[0053] The various embodiments described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), payload programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0054] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0055] In the context of this disclosure, a computer-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of computer-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0056] It should be noted that this disclosure also provides a non-transitory computer-readable storage medium storing computer instructions. These computer instructions are used to cause a computer to execute method 100 and achieve the corresponding technical effects achieved by executing the method in the embodiments of this disclosure; for the sake of brevity, they will not be elaborated further here.

[0057] In addition, this disclosure also provides a computer program product including a computer program that implements method 100 when executed by a processor.

[0058] To provide interaction with a user, the embodiments described above can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0059] The embodiments described above can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with the implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0060] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0061] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0062] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A clear air echo based weather radar reflectivity factor calibration method, characterized by, The method includes: The reflectivity factor data is obtained by synchronously observing the same clear-sky area by a standard weather radar and a weather radar under test; wherein the standard weather radar is a weather radar with normal performance and operates at the first wavelength, and the weather radar under test is a weather radar with questionable performance and operates at the second wavelength. The clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test are selected from the reflectivity factor data observed by the standard weather radar and the weather radar under test. The measured dual-wavelength ratio is calculated based on the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test; the theoretical dual-wavelength ratio is calculated based on the first wavelength and the second wavelength. If the measured dual-wavelength ratio and the theoretical dual-wavelength ratio are not equal, the weather radar under test is determined to be malfunctioning, and the reflectivity factor data observed by the weather radar under test is calibrated based on the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio.

2. The method of claim 1, wherein, The process of filtering the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test from the reflectivity factor data includes: Quality control is performed on the reflectivity factor data observed by the standard weather radar and the weather radar under test; Based on the screening criteria, the clear-sky echo reflectance factor data observed by the standard weather radar and the weather radar under test are selected from the reflectance factor data after quality control.

3. The method of claim 2, wherein, The quality control includes: ground clutter removal, noise suppression, and outlier processing; the screening criteria include: clear sky echo reflectivity factor threshold, clear sky echo area spatial texture features, and clear sky echo area temporal continuity features.

4. The method of claim 1, wherein, The calculation of the measured dual-wavelength ratio based on the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test includes: Based on the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test, the measured dual-wavelength ratio is calculated using the following formula: ； wherein, represents a measured two-wavelength ratio; represents clear sky echo reflectivity factor data observed by a standard weather radar; represents clear sky echo reflectivity factor data observed by a weather radar to be measured.

5. The method of claim 4, wherein, The calculation of the theoretical dual-wavelength ratio based on the first wavelength and the second wavelength includes: The theoretical dual-wavelength ratio is calculated using the following formula based on the first wavelength and the second wavelength: ； wherein, represents a theoretical two-wavelength ratio; represents a first wavelength; represents a second wavelength.

6. The method of claim 5, wherein, The deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio is calculated using the following formula: ； wherein, represents the deviation between the measured two-wavelength ratio and the theoretical two-wavelength ratio; represents the measured two-wavelength ratio; represents the theoretical two-wavelength ratio.

7. The method of claim 1, wherein, The combination of the first wavelength and the second wavelength is selected from any one of the following: S-band and C-band, C-band and X-band, Ka-band and W-band.

8. A clear air echo based meteorological radar reflectivity factor calibration apparatus, characterized by, The device includes: The acquisition module is used to acquire reflectivity factor data obtained by synchronous observation of the same clear sky area by a standard weather radar and a weather radar under test; wherein the standard weather radar is a weather radar with normal performance and operates at the first wavelength, and the weather radar under test is a weather radar with questionable performance and operates at the second wavelength. The filtering module is used to filter out the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test from the reflectivity factor data observed by the standard weather radar and the weather radar under test. The calculation module is used to calculate the measured dual-wavelength ratio based on the clear-sky echo reflectivity factor data observed by the standard weather radar and the weather radar under test; and to calculate the theoretical dual-wavelength ratio based on the first wavelength and the second wavelength. The calibration module is used to determine that the weather radar under test is malfunctioning if the measured dual-wavelength ratio and the theoretical dual-wavelength ratio are not equal, and to calibrate the reflectivity factor data observed by the weather radar under test based on the deviation between the measured dual-wavelength ratio and the theoretical dual-wavelength ratio.

9. An electronic device, comprising: The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the method according to any one of claims 1-7.

10. A non-transitory computer-readable storage medium having stored thereon computer instructions, wherein, The computer instructions are used to cause the computer to perform the method described in any one of claims 1-7.

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