Earth atmosphere Veldet constant determination method, system, equipment and medium

Abstract

The invention provides a method, a system, equipment and a medium for measuring a Weldet constant of the earth atmosphere. The method comprises the following steps: acquiring observation geometric data, atmosphere data and an actually measured Stokes parameter set of a flare area of a remote sensing image under an observation condition; determining a polarization angle set according to the actually measured Stokes parameter set and the atmosphere data; subtracting the observation azimuth angle from the solar azimuth angle to obtain a relative azimuth angle, and performing linear fitting on the relative azimuth angle and the polarization angle set to obtain a magnetic rotation angle value; according to the atmosphere data, the observation zenith angle and the magnetic rotation angle value, determining a Vierdet constant; according to the earth atmosphere Veldet constant determination method provided by the invention, the Veldet constant on an actual atmosphere path can be calculated based on a Faraday effect principle formula according to the total magnetic field intensity of the atmosphere, the action length of polarized light in the atmosphere and a magnetic rotation angle value.

Description

Technical Field

[0001] The present invention relates to the field of optical remote sensing application technology, and in particular to a method, system, equipment and medium for measuring the Verdet constant of the earth's atmosphere. Background Art

[0002] The Verdet Constant is a characteristic constant of matter, which describes the strength of the Faraday effect of a particular material. The Faraday effect, also known as the magneto-optical effect, is a magneto-optical effect. When polarized light passes through a transmission medium with a magnetic field applied, the vibration direction of the polarized light will be deflected. The magnitude of the rotation angle is related to the length of the transmission distance, the strength of the magnetic field and the Verdet constant of the transmission medium (also known as the optical rotation constant). This phenomenon was first discovered by Michael Faraday in 1845 and named after it. The Verdet constant of most non-magnetic materials is very small and is a function of wavelength. Air and water vapor are typical non-magnetic materials. Therefore, the laboratory measurement of their Verdet constant requires the design of precise detectors to determine the optical rotation angle and increase the magnetic field strength in the transmission medium.

[0003] In related measurement experiments abroad, researchers applied a field strength of 210 Gauss to a 0.6m air cavity, and then obtained a curve of the Verdet constant of the air in the laboratory changing with wavelength through phase difference measurement, which is approximately between 2.0e-6min / G / cm and 1.6e-5min / G / cm. The experiment assumes that the air is a mixture of nitrogen and oxygen in a ratio of 0.7809:0.2095. However, the actual atmosphere contains many aerosol particles and absorbing gases, and their complex distribution patterns will affect the Verdet constant of the entire atmosphere. At present, there is no method to measure the actual atmospheric Verdet constant in the solar reflection band (0.4um~2.5um). In addition, relevant domestic researchers published theoretical research demonstrations on the use of magneto-optical effect to measure the earth's magnetic field before 2007, and estimated that the rotation angle of the 490nm blue light band in the sun-synchronous orbit is about 1.7°. The relevant ideas of this study have given us inspiration to use polarization optical remote sensors to detect the actual atmospheric Verdet constant, but the study did not propose a specific process for data extraction and use based on polarization payload data.

[0004] From the above, we can see that the Verdet constant of air has been measured in the laboratory and determined to be a tiny parameter, but there is no suitable measurement method for the Verdet constant in the actual atmosphere in the range of 0.4um to 2.5um. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method, system, equipment and medium for measuring the Verdet constant of the earth's atmosphere, so as to solve the problem in the prior art that "the Verdet constant of air has been measured and determined to be a tiny parameter in the laboratory, but there is no suitable measurement method for the Verdet constant in the actual atmosphere in the range of 0.4um to 2.5um".

[0006] To achieve the above-mentioned and other related purposes, the present invention provides a method for measuring the Verdet constant of the Earth's atmosphere, the method comprising:

[0007] Obtaining a set of measured Stokes parameters of observation geometry data, atmospheric data and a glare area of ​​a remote sensing image under observation conditions, wherein the observation geometry data includes an observation azimuth angle, a solar azimuth angle and an observation zenith angle, and the observation conditions satisfy that an observation angle of a polarization remote sensor is within a preset error interval of an observation principal plane;

[0008] Determine a set of polarization angles according to the measured Stokes parameter set and the atmospheric data;

[0009] Subtracting the observed azimuth from the solar azimuth to obtain a relative azimuth, and performing linear fitting on the relative azimuth and the polarization angle set to obtain a magnetic rotation angle value;

[0010] The Verdet constant is determined according to the atmospheric data, the observation zenith angle and the magnetic rotation angle value.

[0011] In one embodiment of the present invention, the step of linearly fitting the relative azimuth angle and the polarization angle set to obtain the magnetic rotation angle value comprises:

[0012] Generate a fitted linear function by taking the relative azimuth angle as an independent variable and the polarization angle set as a dependent variable;

[0013] The dependent variable value when the independent variable is 180 degrees is calculated according to the fitted linear function as the magnetic rotation angle value.

[0014] In one embodiment of the present invention, the step of obtaining the observed geometric data, atmospheric data and a set of measured Stokes parameters of the glare area of ​​the remote sensing image under the observation conditions comprises:

[0015] Obtain observation geometry data, atmospheric data, remote sensing images and geolocation data under observation conditions;

[0016] Using scene radiation analysis method and polarization change characteristic analysis method to remove cloud-contaminated pixels of the remote sensing image;

[0017] Based on the remote sensing image after removing cloud-contaminated pixels, the glare area of ​​the remote sensing image and the set of measured Stokes parameters of the glare area are determined according to the observation geometry data and the geographic positioning data.

[0018] In one embodiment of the present invention, the atmospheric data includes aerosol optical thickness and aerosol distribution profile, and the step of determining a polarization angle set according to the measured Stokes parameter set and the atmospheric data includes:

[0019] Based on the forward vector radiation transfer algorithm, a set of non-magnetic light Stokes parameters of the glare area is calculated according to the atmospheric data;

[0020] Calculating the difference between the measured Stokes parameter set and the non-magneto-optical Stokes parameter set as a corrected polarization radiation parameter set;

[0021] The polarization angle of each measuring point is calculated according to the polarized radiation parameter set to obtain a polarization angle set:

[0022]

[0023] Among them, AOLP is the polarization angle, U is the intensity difference of the linear polarized light of the polarized light in the two diagonal directions, Q is the intensity difference of the linear polarized light of the polarized light in the horizontal direction and the vertical direction, and jj is the serial number of the measuring point.

[0024] In one embodiment of the present invention, the atmospheric data includes the thickness of the atmosphere and the total magnetic field strength of the atmosphere, and the step of determining the Verdet constant according to the atmospheric data, the observed zenith angle and the magnetic rotation angle value includes:

[0025] Determine the action length of polarized light in the atmosphere according to the thickness of the atmosphere and the observation zenith angle;

[0026] The Verdet constant is determined according to the action length, the total magnetic field strength of the atmosphere and the magnetic rotation angle value.

[0027] In one embodiment of the present invention, the action length is calculated according to the following formula:

[0028] L=H*cosθ VIEW

[0029] Where H is the thickness of the atmosphere, θ VIEW is the observation zenith angle, and L is the action length. In one embodiment of the present invention, the Verdet constant is calculated according to the following formula:

[0030] V=φ MOFE / (B×L)

[0031] Where B is the total magnetic field strength of the atmosphere, L is the action length, φ MOFE is the magnetic rotation angle value, and V is the Verdet constant.

[0032] The present application also provides a system for measuring the Earth's atmosphere Verdet constant, the system comprising:

[0033] A data acquisition module, used to acquire the observed geometric data, atmospheric data and a set of measured Stokes parameters of the glare area of ​​the remote sensing image under the observation conditions, wherein the observed geometric data includes the observation azimuth, the solar azimuth and the observation zenith angle, and the observation conditions satisfy that the observation angle of the polarization remote sensor is within a preset error interval of the observation main plane;

[0034] A polarization angle calculation module, used to determine a polarization angle set according to the measured Stokes parameter set and the atmospheric data;

[0035] A magnetic rotation angle calculation module, used for obtaining a relative azimuth angle by subtracting the observed azimuth angle from the solar azimuth angle, and performing a linear fit between the relative azimuth angle and the polarization angle set to obtain a magnetic rotation angle value;

[0036] The Verdet constant calculation module is used to determine the Verdet constant according to the atmospheric data, the observation zenith angle and the magnetic rotation angle value.

[0037] The present application also provides an electronic device, the electronic device comprising:

[0038] one or more processors;

[0039] A storage device for storing one or more programs, which, when executed by the one or more processors, enables the electronic device to implement the method for determining the Verdet constant of the Earth's atmosphere as described in any one of the above claims.

[0040] The present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor of a computer, the computer is caused to execute a method for determining the Verdet constant of the Earth's atmosphere as described in any one of the above claims.

[0041] As described above, the method, system, device and medium for determining the Earth's atmospheric Verdet constant of the present invention have the following beneficial effects: This application uses an on-orbit polarization remote sensor, takes the strong linear polarized light of the glare as the detection target under observation conditions, and obtains the magnetic rotation angle value by combining the observation geometry data, atmospheric data and the measured Stokes parameter set, etc. Based on the Faraday effect principle formula, according to the total magnetic field intensity of the atmosphere, the action length of the polarized light in the atmosphere and the magnetic rotation angle value, the Verdet constant on the actual atmospheric path is deduced. This application provides an experimental basis for further understanding the optical behavior of gas molecules in electromagnetic fields, and at the same time provides help in exploring the magneto-optical effect and quantum electrodynamics phenomenon of matter in a rarefied environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of a process for determining the Earth's atmosphere Verdet constant provided by an embodiment of the present invention;

[0043] Figure 2 A flowchart of a method for determining the Earth's atmosphere Verdet constant provided by an embodiment of the present invention;

[0044] Figure 3 A structural block diagram of a system for measuring the Earth's atmosphere Verdet constant provided by an embodiment of the present invention;

[0045] Figure 4 The figure is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0047] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0048] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0049] The present invention provides a method for measuring the Verdet constant of the earth's atmosphere, comprising the following steps:

[0050] Step S100: obtaining observation geometry data, atmospheric data and a set of measured Stokes parameters of the glare area of ​​the remote sensing image under observation conditions, wherein the observation geometry data includes an observation azimuth, a solar azimuth and an observation zenith angle, and the observation condition satisfies that the observation angle of the polarization remote sensor is within a preset error interval of the observation principal plane;

[0051] Step S200: determining a polarization angle set according to a measured Stokes parameter set and atmospheric data;

[0052] Step S300: subtract the observed azimuth from the solar azimuth to obtain the relative azimuth, and linearly fit the relative azimuth and polarization angles to obtain the magnetic rotation angle value;

[0053] Step S400: Determine the Verdet constant according to the atmospheric data, the observed zenith angle and the magnetic rotation angle value.

[0054] In step S100, a set of measured Stokes parameters of observation geometry data, atmospheric data and glare areas of remote sensing images under observation conditions are obtained, wherein the observation geometry data includes observation azimuth, solar azimuth and observation zenith angle, and the observation conditions satisfy that the observation angle of the polarization remote sensor is within a preset error range of the observation principal plane.

[0055] In an embodiment of the present application, a set of measured Stokes parameters of observation geometry data, atmospheric data and glare areas of remote sensing images under observation conditions are obtained by a polarization remote sensor, which is an on-orbit remote sensing instrument with band polarization detection capability.

[0056] In the embodiment of the present application, the observation principal plane refers to the incident and observation plane formed when the observation azimuth angle and the solar azimuth angle form 180°. For example, the preset error interval refers to the range of -(2°~5°)~+(2°~5°) of the observation principal plane, and those skilled in the art can also set other appropriate error intervals according to actual conditions.

[0057] When the relative azimuth is equal to 180°, the effect of the atmosphere on the polarization angle is zero, and it is inconvenient to obtain data that is exactly equal to 180° in practice. Therefore, the measured data of the observation angle near 180° is used for calculation. These data can be considered to have received slight atmospheric interference, and the atmospheric influence still needs to be deducted in the subsequent steps.

[0058] Specifically, the steps of obtaining the observed geometric data, atmospheric data and a set of measured Stokes parameters of the glare area of ​​the remote sensing image under the observation conditions include:

[0059] Step S110: Acquire observation geometry data, atmospheric data, remote sensing images and geographic positioning data under observation conditions;

[0060] Step S120: removing cloud-contaminated pixels from the remote sensing image using a scene radiation analysis method and a polarization change characteristic analysis method;

[0061] Step S130: Based on the remote sensing image after removing cloud-contaminated pixels, determine the glare area of ​​the remote sensing image and the set of measured Stokes parameters of the glare area according to the observed geometric data and the geographic positioning data.

[0062] In step S110, the observation geometry data describes the geometric relationship between the observer (polarization remote sensor) and the observation target point, and is used to accurately describe the observation angle and the propagation path of light. The geolocation data describes the geographic location information of the observer (polarization remote sensor) and the observation target point, and is used to determine the precise position of the polarization remote sensor and the observation target point for spatial analysis and data correction.

[0063] In step S120, the scene radiation analysis method and the polarization change characteristic analysis method are used to remove cloud-contaminated pixels of the remote sensing image to improve the quality of the remote sensing image and the accuracy of subsequent analysis. The scene radiation analysis method and the polarization change characteristic analysis method are common analysis methods in this field, so they are not described in detail.

[0064] In step S130, the strong linear polarized light of the sea surface glare is mainly used as the detection target. The light in the glare area often has a strong polarization characteristic. This strong polarization effect is conducive to the detection and analysis of physical processes in the atmosphere. The measured Stokes parameter set is expressed as: Stokes parameters are used to reflect the polarization characteristics of light. I describes the total intensity or total irradiance of light, Q describes the intensity difference between linearly polarized light in the horizontal direction (relative to the reference axis) and the vertical direction, and U describes the intensity difference between linearly polarized light in the two diagonal directions (i.e., the directions of +45° and -45° relative to the reference axis).

[0065] In step S200, a set of polarization angles is determined based on a set of measured Stokes parameters and atmospheric data.

[0066] Specifically, the atmospheric data includes aerosol optical thickness and aerosol distribution profile, and the steps of determining the polarization angle set according to the measured Stokes parameter set and the atmospheric data include:

[0067] Step S210: Calculate the non-magnetic light Stokes parameter set of the glare area according to the atmospheric data based on the forward vector radiation transfer algorithm;

[0068] Step S220: Calculate the difference between the measured Stokes parameter set and the non-magneto-optical Stokes parameter set as the corrected polarization radiation parameter set;

[0069] Step S230: Calculate the polarization angle of each measuring point according to the polarized radiation parameter set to obtain a polarization angle set:

[0070]

[0071] Among them, AOLP is the polarization angle, U is the intensity difference of the linear polarized light of the polarized light in the two diagonal directions, Q is the intensity difference of the linear polarized light of the polarized light in the horizontal direction and the vertical direction, and jj is the serial number of the measuring point.

[0072] For example, the atmospheric data includes aerosol optical thickness and aerosol distribution profile. In some embodiments, the atmospheric data may also include water vapor content, ozone content, etc.

[0073] In step S210, the magneto-optical-free Stokes parameter set reflects the natural polarization state of light in the atmosphere, excluding the influence of the magneto-optical effect. The magneto-optical-free Stokes parameter set is expressed as The vector radiation transfer algorithm is a common algorithm in this field, so it will not be described in detail.

[0074] For example, the vector radiation transfer algorithm can be used to calculate the Stokes parameters of the top of the atmosphere without magneto-optical effect at the observation angle adjacent to the observation main plane under the corresponding spectral channel. The spectral channel corresponds to the wavelength of the light radiation detected by the polarization remote sensor, which is obtained through a narrow-band filter. The data commonly used in the embodiments of the present application usually have three channels: 490 band, 670 band and 865 band.

[0075] In step S220, the difference between the measured Stokes parameter set and the non-magneto-optical Stokes parameter set is calculated, which is expressed as: The corrected polarization radiation parameter set can extract the influence of the magneto-optical effect on the polarization state of light by removing the natural polarization effect. That is, the corrected polarization radiation parameter set eliminates the interference of the natural polarization of the atmosphere.

[0076] In step S230, specifically, the polarization angle is calculated. The above formula is a common formula in the art, so it will not be described in detail.

[0077] In step S300, the relative azimuth is obtained by subtracting the observed azimuth from the solar azimuth, and the relative azimuth and polarization angles are linearly fitted to obtain the magnetic rotation angle value.

[0078] Specifically, the step of linearly fitting the relative azimuth angle and polarization angle set to obtain the magnetic rotation angle value includes:

[0079] Step S310, generating a fitted linear function by taking the relative azimuth angle as an independent variable and the polarization angle set as a dependent variable;

[0080] Step S320, calculating the dependent variable value when the independent variable is 180 degrees according to the fitted linear function as the magnetic optical rotation angle value.

[0081] In the embodiment of the present application, first, the polarization angle set is set as the variable set Y, and the observed relative azimuth corresponding to the polarization angle set is taken as the independent variable set in and are the solar azimuth and observation azimuth, respectively. Then, the least squares method is used to fit the linear function Y=aX+b to obtain the fitting coefficients a and b. Finally, the dependent variable value when the independent variable is 180 degrees is calculated based on the fitted linear function, which is used as the magnetic rotation angle value, expressed as φ MOFE .

[0082] The relative azimuth angle is used as an independent variable set in order to form a characteristic space near the main observation plane. In this characteristic space, the atmosphere will not interfere with polarization only when the relative azimuth angle is theoretically 180°. However, it is difficult to obtain data with a relative azimuth angle of 180° in the measured data. Usually, the measured points near 180° are interpolated to generate data close to the theoretical value.

[0083] In step S400, the Verdet constant is determined according to the atmospheric data, the observed zenith angle and the magnetic rotation angle value.

[0084] Specifically, the atmospheric data includes the thickness of the atmosphere and the total magnetic field strength of the atmosphere. The steps of determining the Verdet constant according to the atmospheric data, the observed zenith angle and the magnetic rotation angle value include:

[0085] Step S410: determining the effective length of polarized light in the atmosphere according to the thickness of the atmosphere and the observation zenith angle.

[0086] Step S420: Determine the Verdet constant according to the action length, the total magnetic field strength of the atmosphere and the magnetic rotation angle value.

[0087] In step S410, the effective length of polarized light in the atmosphere refers to the effective distance that polarized light propagates in the atmosphere, and the effective length is calculated according to the following formula:

[0088] L=H*cosθ VIEW

[0089] Where H is the thickness of the atmosphere, θ VIEW is the observation zenith angle, and L is the effective length.

[0090] In step S420, the Verdet constant is calculated according to the following formula:

[0091] V=φ MOFE / (B×L)

[0092] Where B is the total magnetic field strength of the atmosphere, L is the effective length, φ MOFE is the magnetic rotation angle value, and V is the Verdet constant.

[0093] For example, the total magnetic field strength of the atmosphere is calculated as follows: According to the International Geomagnetic Field Reference Model IGRF, the atmosphere is divided into n layers, and the magnetic field strength in each layer i is considered to be a fixed value, and then the total magnetic field strength of the atmosphere is obtained by superposition. The total magnetic field strength of the atmosphere is expressed as: The International Geomagnetic Reference Model IGRF is a common model in this field, so its details will not be described again.

[0094] The following specifically describes the actual process and operation examples of data cleaning and calculation using existing remote sensor data. The existing remote sensor can be the third-generation French polarization reflectivity meter (PARASOL), the payload has available data ranging from 2005 to 2006, and the atmospheric polarization radiance data detected by the payload is stored in H5 format files.

[0095] Step S1: Get the latitude data set from the Gelocation tag of the above data and set it as set F lat (rol,col), get the longitude dataset and set it as dataset F lon (rol,col); Get the land and sea flag dataset (land_sea_flag), set it to D sl (rol,col).

[0096] Step S2: Get the cloud pixel label dataset (cloud_indicator) from the Data_Fields tag of the above data, set it as D cloud (rol,col).

[0097] Step S3, obtain the I, Q, and U data sets of the polarization band from the Data_Direction_Fields tag of the above data (corresponding to I490P, Q490P, U490P, I670P, Q670P, U670P, I870P, Q870P, and U870P, respectively), and set 3 sets for each polarization spectrum band for storage: NI k (angle,rol,col),NQ k (angle,rol,col),NU k (angle,rol,col), where the subscript k represents the spectral band, angle represents the angle layer, and rol and col represent the corresponding grid row and column numbers.

[0098] Step S4: Obtain the solar zenith angle dataset (thetas), the observed zenith angle dataset (thetav), and the relative azimuth angle dataset (phi) from the Data_Direction_Fields tag, and set the datasets for storage.

[0099] Step S5, setting a small matrix set:

[0100]

[0101] Among them, tonum is the total number of small matrices. The internal elements represent the data variables after the angle and sequence number traversal.

[0102] Step S6: Loop traversal starts from the small matrix data set. The loop structure and internal loop steps are as follows:

[0103] Step S6.1: The outermost loop is the small matrix sequence number i. A measurement point data storage set is preset inside the outermost loop. These data are the measurement point data sets obtained in each small matrix.

[0104] Step S6.2: For the currently traversed small matrix i, set up a double loop starting from the row and column number starting point, and select the cloud judgment data small matrix D cloud D sl The value of is used as the criterion. When it is marked as ocean and the cloud judgment data is clean, it is preliminarily considered that the measured data point meets the requirements, and then the next step of angle cycle is carried out.

[0105] Step S6.3, in the angle loop, set anglenum as the current angle number, and obtain the current observation angle according to anglenum and the small matrix row and column numbers sm and sn. When the observed relative azimuth satisfies When the row and column numbers and angle numbers are stored in the measuring point data set Vresult , otherwise return to step 6.2.

[0106] Step S6.4: After all elements of the small matrix with serial number i have been traversed, set i+1 and return to step 6.2 to start traversing the next small matrix.

[0107] Step S6.5: When i=totnum, stop traversal. result Contains all measurement point data sets, V result The elements in are all one-dimensional lists of equal length:

[0108]

[0109] Step S6.6: After obtaining the measurement point data set according to step 6.5, Extract and get the polarization component data list, assuming that jj is the data number NQ of each measurement point k , N.U. k The measured value of the component.

[0110] Step S7: While calculating the polarization angle parameter, extract the longitude and latitude information of the corresponding serial number, and search for the atmospheric data (such as aerosol optical thickness, water vapor content, ozone content, etc.) at the longitude and latitude of the target.

[0111] Step S8: Extract geometric observation data according to the data sequence number jj of each scene, and then perform radiation transfer calculation to obtain the composite NQ of the atmosphere and the sea surface. katm (jj), NU katm (jj) Component contribution.

[0112] Step S9: After deducting the contribution of the atmospheric and surface polarization components from the measured value, the remaining value is considered to be the component of the magnetic field rotation effect:

[0113] NQ kmag (jj) = NQ k (jj)-NQ katm (jj)

[0114] NU kmag (jj)=NU k (jj)-NU katm (jj)

[0115] Step S10, calculating the magneto-polarization rotation angle according to the polarization angle calculation formula:

[0116]

[0117] Step S11, calculating the magnetic field strength B according to the longitude and latitude and the measurement time point.

[0118] Step S12, calculating the transmission path L according to the observed zenith angle and the atmosphere height (atmosphere thickness) (set to 100 km).

[0119] Step S13: Calculate the atmospheric Verdet constant V according to steps S10 to S12.

[0120] The present application also provides a system for measuring the Earth's atmosphere Verdet constant, the system comprising:

[0121] A data acquisition module is used to acquire the observed geometric data, atmospheric data and a set of measured Stokes parameters of the glare area of ​​the remote sensing image under the observation conditions, wherein the observed geometric data includes the observation azimuth, the solar azimuth and the observation zenith angle, and the observation conditions satisfy that the observation angle of the polarization remote sensor is within a preset error interval of the observation main plane;

[0122] A polarization angle calculation module is used to determine a polarization angle set based on a measured Stokes parameter set and atmospheric data;

[0123] A magnetic rotation angle calculation module is used to obtain a relative azimuth by subtracting the observed azimuth from the solar azimuth, and to obtain a magnetic rotation angle value by linearly fitting the relative azimuth and polarization angle sets;

[0124] The Verdet constant calculation module is used to determine the Verdet constant based on atmospheric data, observed zenith angle and magnetic rotation angle values.

[0125] The electronic device 1 may include a memory 12, a processor 13 and a bus, and may also include a computer program stored in the memory 12 and executable on the processor 13, such as a program for determining the Verdet constant of the earth's atmosphere.

[0126] Among them, the memory 12 includes at least one type of readable storage medium, and the readable storage medium includes flash memory, mobile hard disk, multimedia card, card-type memory (for example: SD or DX memory, etc.), magnetic memory, disk, optical disk, etc. In some embodiments, the memory 12 can be an internal storage unit of the electronic device 1, such as a mobile hard disk of the electronic device 1. In other embodiments, the memory 12 can also be an external storage device of the electronic device 1, such as a plug-in mobile hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 1. Further, the memory 12 can also include both an internal storage unit of the electronic device 1 and an external storage device. The memory 12 can not only be used to store application software and various types of data installed in the electronic device 1, such as the code for determining the Earth's atmosphere Verdet constant, etc., but can also be used to temporarily store data that has been output or is to be output.

[0127] In some embodiments, the processor 13 may be composed of an integrated circuit, for example, a single packaged integrated circuit, or a plurality of packaged integrated circuits with the same or different functions, including one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and a combination of various control chips. The processor 13 is the control core (Control Unit) of the electronic device 1, and uses various interfaces and lines to connect various components of the entire electronic device 1, and executes or executes programs or modules stored in the memory 12 (such as the determination of the Earth's atmosphere Verdet constant, etc.), and calls the data stored in the memory 12 to execute various functions of the electronic device 1 and process data.

[0128] The processor 13 executes the operating system and various installed application programs of the electronic device 1. The processor 13 executes the application programs to implement the steps in the above-mentioned method for determining the Verdet constant of the earth's atmosphere.

[0129] Exemplarily, the computer program may be divided into one or more modules, which are stored in the memory 12 and executed by the processor 13 to complete the present application. The one or more modules may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program in the electronic device 1. For example, the computer program may be divided into a data acquisition module 10, a polarization angle calculation module 20, a magnetic rotation angle calculation module 30, and a Verdet constant calculation module 40.

[0130] The above-mentioned integrated unit implemented in the form of a software function module can be stored in a computer-readable storage medium, and the computer-readable storage medium can be non-volatile or volatile. The above-mentioned software function module is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, a computer device, or a network device, etc.) or a processor to perform part of the functions of the Verdet constant calculation module method described in each embodiment of the present application.

[0131] Although the atmospheric Verdet constant is very small, for the entire atmospheric layer with an action path of more than 100 km, the magneto-optical effect can still cause the polarization angle of the flare to undergo a measurable deflection. However, the actual atmospheric rotation effect on polarized light is more complicated. First, the strength of the geomagnetic field varies with position and altitude. In addition, on the main observation plane, although the scattering of atmospheric aerosols and molecules does not directly affect the polarization angle, it is still possible to change the transmission path through multiple scattering, and indirectly affect the constancy of the polarization angle through the depolarization effect. These effects need to be described by more complex mathematical models under the long-range action of the weak geomagnetic field. At present, polarized radiation transmission without considering the effect of the magnetic field can be used for calculation and correction.

[0132] In summary, the present application uses an on-orbit polarization remote sensor, takes the strong linear polarized light of the glare as the detection target under observation conditions, combines the observation geometry data, atmospheric data and the measured Stokes parameter set to obtain the magnetic rotation angle value, and based on the Faraday effect principle formula, according to the total magnetic field intensity of the atmosphere, the action length of the polarized light in the atmosphere and the magnetic rotation angle value, the Verdet constant on the actual atmospheric path is deduced. The present application provides an experimental basis for further understanding the optical behavior of gas molecules in electromagnetic fields, and at the same time provides help in exploring the magneto-optical effect and quantum electrodynamics phenomenon of matter in a rarefied environment. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0133] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for determining the Earth's atmospheric Verdet constant, characterized in that: The method comprises: Obtaining a set of measured Stokes parameters of observation geometry data, atmospheric data and a glare area of ​​a remote sensing image under observation conditions, wherein the observation geometry data includes an observation azimuth angle, a solar azimuth angle and an observation zenith angle, and the observation conditions satisfy that an observation angle of a polarization remote sensor is within a preset error interval of an observation principal plane; Determine a set of polarization angles according to the measured Stokes parameter set and the atmospheric data; Subtracting the observed azimuth from the solar azimuth to obtain a relative azimuth, and performing linear fitting on the relative azimuth and the polarization angle set to obtain a magnetic rotation angle value; The Verdet constant is determined according to the atmospheric data, the observation zenith angle and the magnetic rotation angle value.

2. The method for measuring the Earth's atmosphere Verdet constant according to claim 1, characterized in that: The step of linearly fitting the relative azimuth angle and the polarization angle set to obtain the magnetic rotation angle value comprises: Generate a fitted linear function by taking the relative azimuth angle as an independent variable and the polarization angle set as a dependent variable; The dependent variable value when the independent variable is 180 degrees is calculated according to the fitted linear function as the magnetic rotation angle value.

3. The method for measuring the Earth's atmosphere Verdet constant according to claim 1, characterized in that: The step of obtaining the observed geometric data, atmospheric data and a set of measured Stokes parameters of the glare area of ​​the remote sensing image under the observation conditions comprises: Obtain observation geometry data, atmospheric data, remote sensing images and geolocation data under observation conditions; Using scene radiation analysis method and polarization change characteristic analysis method to remove cloud-contaminated pixels of the remote sensing image; Based on the remote sensing image after removing cloud-contaminated pixels, the glare area of ​​the remote sensing image and the set of measured Stokes parameters of the glare area are determined according to the observation geometry data and the geographic positioning data.

4. The method for measuring the Earth's atmosphere Verdet constant according to claim 1, characterized in that: The atmospheric data includes aerosol optical thickness and aerosol distribution profile, and the step of determining a polarization angle set according to the measured Stokes parameter set and the atmospheric data includes: Based on the forward vector radiation transfer algorithm, a set of non-magnetic light Stokes parameters of the glare area is calculated according to the atmospheric data; Calculating the difference between the measured Stokes parameter set and the non-magneto-optical Stokes parameter set as a corrected polarization radiation parameter set; The polarization angle of each measuring point is calculated according to the polarized radiation parameter set to obtain a polarization angle set: Among them, AOLP is the polarization angle, the plane perpendicular to the observation principal plane is used as the plane of polarization angle rotation, U is the intensity difference of the linear polarized light of the polarized light in the two diagonal directions, Q is the intensity difference of the linear polarized light of the polarized light in the horizontal direction and the vertical direction, and jj is the serial number of the measuring point.

5. The method for measuring the Earth's atmosphere Verdet constant according to claim 1, characterized in that: The atmospheric data includes the thickness of the atmosphere and the total magnetic field strength of the atmosphere. The step of determining the Verdet constant according to the atmospheric data, the observed zenith angle and the magnetic rotation angle value includes: Determine the action length of polarized light in the atmosphere according to the thickness of the atmosphere and the observation zenith angle; The Verdet constant is determined according to the action length, the total magnetic field strength of the atmosphere and the magnetic rotation angle value.

6. The method for measuring the Earth's atmosphere Verdet constant according to claim 5, characterized in that: The action length is calculated according to the following formula: L=H*cosθ VIEW Where H is the thickness of the atmosphere, θ VIEW is the observation zenith angle, and L is the effective length.

7. The method for measuring the Earth's atmosphere Verdet constant according to claim 6, characterized in that: The Verdet constant is calculated according to the following formula: V=φ MOFE / (B×L) Where B is the total magnetic field strength of the atmosphere, L is the action length, φ MOFE is the magnetic rotation angle value, and V is the Verdet constant.

8. A system for measuring the Earth's atmosphere Verdet constant, characterized in that: The system comprises: A data acquisition module, used to acquire the observed geometric data, atmospheric data and a set of measured Stokes parameters of the glare area of ​​the remote sensing image under the observation conditions, wherein the observed geometric data includes the observation azimuth, the solar azimuth and the observation zenith angle, and the observation conditions satisfy that the observation angle of the polarization remote sensor is within a preset error interval of the observation main plane; A polarization angle calculation module, used to determine a polarization angle set according to the measured Stokes parameter set and the atmospheric data; A magnetic rotation angle calculation module, used for obtaining a relative azimuth angle by subtracting the observed azimuth angle from the solar azimuth angle, and performing a linear fit between the relative azimuth angle and the polarization angle set to obtain a magnetic rotation angle value; The Verdet constant calculation module is used to determine the Verdet constant according to the atmospheric data, the observation zenith angle and the magnetic rotation angle value.

9. An electronic device, characterized in that: The electronic device comprises: one or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, enables the electronic device to implement the method for determining the Verdet constant of the Earth's atmosphere as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor of a computer, the computer is caused to execute the method for measuring the Verdet constant of the earth's atmosphere as described in any one of claims 1 to 7.

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