Sky polarization mode modeling method considering influence of surface reflection depolarization

Abstract

The invention discloses a sky polarization mode modeling method considering the influence of surface reflection depolarization, and belongs to the technical field of atmospheric optics and polarized light navigation. The problem that in the prior art, an all-sky polarization mode modeling method does not fully and accurately consider an earth surface reflection depolarization influence mechanism, and consequently calculation of the sky polarization degree distribution overall deviation actual measurement result is caused is solved. The solar zenith angle and azimuth angle are calculated according to the geographic position and observation time; calculating an ideal sky polarization mode according to a Berry model of sky polarization vector distribution; mapping transformation from a two-dimensional plane to a three-dimensional spherical surface is realized according to a spherical pole projection transformation relation; calculating an all-celestial-sphere surface reflection depolarization coefficient by combining the observation height, the observation wavelength, the solar zenith angle and the surface reflectance; and multiplying the earth surface reflection depolarization coefficient by the ideal sky polarization mode to obtain the sky polarization mode considering the influence of earth surface reflection depolarization. According to the method, the calculation accuracy of the sky polarization model is effectively improved, and the method can be applied to sky polarization mode modeling.

Description

Technical Field

[0001] The invention relates to a sky polarization mode modeling method, in particular to a sky polarization mode modeling method taking into account the influence of surface reflection depolarization, and belongs to the technical field of atmospheric optics and polarized light navigation. Background Art

[0002] Navigation technology is widely used in human production and life, military operations and scientific exploration. With the advancement of science and technology, the types of navigation technology are endless. In the existing technology, the satellite global positioning system uses satellite signals to achieve high-precision positioning of the carrier all day long, but it is easily affected by electromagnetic interference and fails. The inertial navigation system completes navigation by integrating the acceleration and angular acceleration of the carrier. It is not easily interfered by the outside world, but the navigation error will accumulate over time and cannot be used for a long time. Therefore, finding a navigation method that uses the physical properties of the natural environment to achieve high precision, long time, strong concealment, and resistance to external interference has become a new research hotspot in the field of navigation technology.

[0003] In recent years, the polarization dimension information of light has been widely used in the fields of navigation, remote sensing, and target detection. When light is irradiated to the earth, it interacts with the atmosphere and the surface environment to form a sky polarization pattern with a stable distribution law. The sky polarization pattern contains important navigation information such as the direction of the sun, zenith, and celestial pole. Constructing an analytical model to accurately describe the sky polarization pattern has important guiding significance for realizing the navigation and positioning of the carrier; the single scattering pattern of atmospheric molecules to light is described by the Rayleigh model, but the complexity of the ground environment makes the sky polarization pattern deviate significantly from the Rayleigh model. The existing sky polarization model is relatively simple in analyzing the influence of surface reflection depolarization, and does not fully reflect the distribution law of polarized light under different surface types and different observation conditions. The existing model only discusses the influence law of the upper hemisphere space, and the prediction of the polarization degree in the zenith direction and the horizontal direction is quite different from the ground and aerial measurement results, which cannot meet the application requirements of the aviation platform, making the application scope and accuracy of the model very limited.

[0004] In summary, a method for modeling the sky polarization pattern that takes into account the effect of surface reflection depolarization is needed. Summary of the invention

[0005] A brief overview of the present invention is provided below in order to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify key or important parts of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0006] In view of this, in order to solve the problem that the overall deviation of the calculated sky polarization distribution is caused by the traditional full-sky polarization pattern modeling method in the prior art not fully and accurately considering the influence mechanism of surface reflection depolarization, the present invention provides a sky polarization pattern modeling method taking into account the influence of surface reflection depolarization.

[0007] The technical solution is as follows: A method for modeling sky polarization patterns taking into account the influence of surface reflection depolarization comprises the following steps:

[0008] S1. Calculate the sun's zenith angle and azimuth angle based on the geographical location and observation time;

[0009] S2. According to the established Berry model, the ideal sky polarization degree is calculated;

[0010] S3. Mapping the polarization degree diagram to a three-dimensional spherical surface according to the stereographic projection coordinate transformation relationship;

[0011] S4. Obtain the reflectance of the ground surface at the observation location in combination with the spectral database;

[0012] S5. Calculate the depolarization coefficient of the entire celestial surface reflection by combining the observation altitude, observation wavelength, solar zenith angle and surface reflectivity;

[0013] S6. Multiply the ideal sky polarization degree by the surface reflection depolarization coefficient to obtain the sky polarization mode that takes into account the influence of surface reflection depolarization.

[0014] Furthermore, in S1, the azimuth angle A of the sun s It is expressed as:

[0015]

[0016] Among them, δ is the right ascension of the sun, h s is the altitude angle of the sun, φ o is the geographical latitude of the observation location;

[0017] The sun's altitude angle h s It is expressed as:

[0018] sinh s = sinφ o sinδ+cosφ o cosδcosω

[0019] Where, ω is the solar hour angle;

[0020] The solar hour angle ω is expressed as:

[0021] ω=η o +(UT1+E)×15-180

[0022] Among them, ηo is the geographical longitude of the observation location, E is the difference between true solar time and mean solar time, and UT1 is Greenwich local time;

[0023] The sun's zenith angle θ s It is expressed as:

[0024] θ s =90°-h s .

[0025] Furthermore, in S2, the Berry model is established on a plane solar direction coordinate system, and the complex coordinate of the sun in the plane solar direction coordinate system is ξ, ξ=iy s , where i is the imaginary unit, y s The projection coordinates of the sun on the y-axis of the plane solar direction coordinate system are obtained, and the complex coordinates of the four polarization neutral points in the sky are obtained;

[0026] The complex coordinate v1 of the first polarization neutral point is expressed as:

[0027]

[0028] Among them, A0 represents the parameter of polarization neutral point splitting degree, ζ + is the complex coordinate of the first polarization neutral point in the Berry model;

[0029] The complex coordinate v2 of the second polarization neutral point is expressed as:

[0030]

[0031] Among them, - is the complex coordinate of the second polarization neutral point in the Berry model;

[0032] The complex coordinate v3 of the third polarization neutral point is expressed as:

[0033]

[0034] in, is the complex conjugate value of the complex coordinates of the first polarization neutral point in the Berry model;

[0035] The complex coordinate v4 of the fourth polarization neutral point is expressed as:

[0036]

[0037] in, is the complex conjugate value of the complex coordinate of the second polarization neutral point in the Berry model;

[0038] The sky polarization intensity ω(ζ) at the complex coordinates of any observed point ζ in the plane solar direction coordinate system is expressed as:

[0039]

[0040] ζ=rexp(iφ)

[0041] Where r is the polar diameter of the observed point ζ on the complex plane, φ is the polar angle of the observation point on the complex plane, i is the imaginary unit, exp is the natural exponential function, and according to the Berry model, the ideal sky polarization DoP is obtained B .

[0042] Furthermore, in S3, the stereographic projection coordinate transformation relationship is the correspondence between the point (r, φ) in the plane sun direction coordinate system and the point (R, α, β) in the three-dimensional spherical coordinate system;

[0043] The corresponding relationship is expressed as:

[0044] R≡1

[0045]

[0046] β=φ

[0047] Among them, R is the distance between the observed point and the center of the sphere in the three-dimensional spherical coordinate system, α is the elevation angle of the observed point in the three-dimensional spherical coordinate system, and β is the azimuth angle of the observed point in the three-dimensional spherical coordinate system.

[0048] Furthermore, the S5 specifically includes the following steps:

[0049] S51. Based on the calculated isotropic surface reflection depolarization coefficient P in the upper hemisphere space 1+ and the anisotropic surface reflection depolarization coefficient P in the upper hemisphere space 2+ , we can get the surface reflection depolarization coefficient P in the upper hemisphere space with the observation zenith angle θ∈[0°,90°] + ;

[0050] S52. Based on the calculated isotropic surface reflection depolarization coefficient P in the lower hemisphere space 1- and the anisotropic surface reflection depolarization coefficient P in the lower hemisphere space 2- , we can get the surface reflection depolarization coefficient P in the lower hemisphere space with the observation zenith angle θ∈[90°,180°] - ;

[0051] S53. The surface reflection depolarization coefficient P in the upper hemisphere space according to the observed zenith angle θ∈[0°,90°] + and the surface reflection depolarization coefficient P in the lower hemisphere space with the observation zenith angle θ∈[90°,180°] - , and obtain the surface reflection depolarization coefficient P;

[0052] In the above S51, the isotropic surface reflection depolarization coefficient P in the upper hemisphere space 1+ It is expressed as:

[0053] P 1+ =(cos(Aθ s )) B ·e -Cρ* +(1-(cos(Aθ s )) B )

[0054] ρ*=ρ·e -Kh

[0055] Among them, A is the first empirical coefficient, B is the second empirical coefficient, C is the third empirical coefficient, ρ is the surface reflectivity, K is the eleventh empirical coefficient, h is the observation height, θ s is the solar zenith angle, ρ * is the height equivalent surface reflectivity;

[0056] Anisotropic surface reflection depolarization coefficient P in the upper hemisphere space 2+ It is expressed as:

[0057]

[0058] Wherein, D is the fourth empirical coefficient, E is the fifth empirical coefficient, F is the sixth empirical coefficient, G is the seventh empirical coefficient, and sec is the secant function;

[0059] In the S52, the isotropic surface reflection depolarization coefficient P in the lower hemisphere space 1- It is expressed as:

[0060] P 1- =P 1+ ·P 2+ (θ=90°)

[0061] Anisotropic surface reflection depolarization coefficient P in the lower hemisphere space 2- It is expressed as:

[0062] P 2- =[Ψ·(cos(θ)+1) (Λ+1) +(1-Ψ)]

[0063]

[0064] Among them, H is the eighth empirical coefficient, I is the ninth empirical coefficient, J is the tenth empirical coefficient, and a i is the twelfth empirical coefficient, b i is the thirteenth empirical coefficient, c i is the fourteenth empirical coefficient, d iis the fifteenth empirical coefficient, Ψ is the first empirical function, Λ is the second empirical function, and the empirical coefficients are all obtained based on the known observation wavelength;

[0065] In S53, the surface reflection depolarization coefficient P is expressed as:

[0066]

[0067] Further, in S6, the sky polarization mode DoP is expressed as:

[0068] DoP=DoP B ·P.

[0069] The beneficial effects of the present invention are as follows: in view of the problem that the predicted value of the sky polarization degree under the actual observation environment by the traditional model has a large deviation from the measured value, the present invention analyzes the depolarization mechanism of surface reflection, and summarizes the depolarization effect of surface reflection into two parts: isotropic depolarization effect and anisotropic depolarization effect, thereby effectively improving the accuracy of the calculation results of the sky polarization model;

[0070] The present invention aims at observation platforms at different flight altitudes, expands the existing atmospheric polarization model from the upper hemisphere space to the full celestial sphere space including the 4π solid angle range, and corrects the deficiency of the existing traditional model that the polarization degree is abnormally zeroed in the horizontal observation direction, so that the new sky polarization model can be applied to aviation platforms;

[0071] By analyzing the depolarization mechanism of surface reflection, the present invention expands the existing sky polarization model in four aspects: observation altitude, observation wavelength, observation angle range, and available solar altitude range, thereby improving the environmental adaptability of the model.

[0072] In summary, based on the existing Berry model, the present invention fully considers the influence mechanism of surface reflection depolarization, narrows the difference between the sky polarization distribution predicted by the new model and the sky polarization distribution observed in the actual environment, broadens the application scope of the existing sky polarization model, and can provide an effective reference for the performance analysis and system design of the polarized light navigation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0074] Figure 1 A flowchart of a method for modeling sky polarization patterns taking into account the effect of depolarization reflected by the ground surface;

[0075] Figure 2 A schematic diagram of an embodiment of the effect process of surface reflection depolarization established;

[0076] Figure 3 A schematic diagram of an embodiment of a three-dimensional space coordinate system of an atmospheric polarization model established;

[0077] Figure 4 The figure is a schematic diagram of an embodiment of the stereographic projection process for converting a planar sun direction coordinate system into a three-dimensional spherical coordinate system. DETAILED DESCRIPTION

[0078] In order to make the technical solutions and advantages of the embodiments of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0079] refer to Figure 1-Figure 4 , the present embodiment is described in detail, a method for modeling sky polarization patterns taking into account the influence of surface reflection depolarization, comprising the following steps:

[0080] S1. Calculate the sun's zenith angle and azimuth angle based on the geographical location and observation time;

[0081] S2. Establish a plane sun direction coordinate system, and calculate the ideal sky polarization degree according to the Berry model on the plane sun direction coordinate system;

[0082] S3. Establish a three-dimensional spherical coordinate system, and map the polarization degree diagram to a three-dimensional spherical surface according to the stereographic projection coordinate transformation relationship;

[0083] S4. Acquire the surface reflectance of the observation location in combination with the spectral database;

[0084] S5. Calculate the depolarization coefficient of the entire celestial surface reflection by combining the observation altitude, observation wavelength, solar zenith angle and surface reflectivity;

[0085] S6. Multiply the ideal sky polarization degree by the surface reflection depolarization coefficient to obtain the sky polarization mode that takes into account the influence of surface reflection depolarization.

[0086] Furthermore, in S1, the azimuth angle A of the sun s It is expressed as:

[0087]

[0088] Among them, δ is the right ascension of the sun, h s is the altitude angle of the sun, φ o is the geographical latitude of the observation location;

[0089] The sun's altitude angle h s It is expressed as:

[0090] sinh s = sinφ o sinδ+cosφ o cosδcosω

[0091] Where, ω is the solar hour angle;

[0092] The solar hour angle ω is expressed as:

[0093] ω=η o +(UT1+E)×15-180

[0094] Among them, η o is the geographical longitude of the observation location, E is the difference between true solar time and mean solar time, and UT1 is Greenwich local time;

[0095] The sun's zenith angle θ s It is expressed as:

[0096] θ s =90°-h s .

[0097] Furthermore, in S2, the Berry model is established on a plane solar direction coordinate system, and the complex coordinate of the sun in the plane solar direction coordinate system is ξ, ξ=iy s , where i is the imaginary unit, y s The projection coordinates of the sun on the y-axis of the plane solar direction coordinate system are obtained, and the complex coordinates of the four polarization neutral points in the sky are obtained;

[0098] The complex coordinate v1 of the first polarization neutral point is expressed as:

[0099]

[0100] Among them, A0 represents the parameter of polarization neutral point splitting degree, ζ + is the complex coordinate of the first polarization neutral point in the Berry model;

[0101] The complex coordinate v2 of the second polarization neutral point is expressed as:

[0102]

[0103] Among them, - is the complex coordinate of the second polarization neutral point in the Berry model;

[0104] The complex coordinate v3 of the third polarization neutral point is expressed as:

[0105]

[0106] in, is the complex conjugate value of the complex coordinates of the first polarization neutral point in the Berry model;

[0107] The complex coordinate v4 of the fourth polarization neutral point is expressed as:

[0108]

[0109] in, is the complex conjugate value of the complex coordinate of the second polarization neutral point in the Berry model;

[0110] The sky polarization intensity ω(ζ) at the complex coordinates of any observed point ζ in the plane solar direction coordinate system is expressed as:

[0111]

[0112] ζ=rexp(iφ)

[0113] Where r is the polar diameter of the observed point ζ on the complex plane, φ is the polar angle of the observation point on the complex plane, i is the imaginary unit, exp is the natural exponential function, and according to the Berry model, the ideal sky polarization DoP is obtained B .

[0114] Furthermore, in S3, the stereographic projection coordinate transformation relationship is the correspondence between the point (r, φ) in the plane sun direction coordinate system and the point (R, α, β) in the three-dimensional spherical coordinate system;

[0115] The corresponding relationship is expressed as:

[0116] R≡1

[0117]

[0118] β=φ

[0119] Among them, R is the distance between the observed point and the center of the sphere in the three-dimensional spherical coordinate system, α is the elevation angle of the observed point in the three-dimensional spherical coordinate system, and β is the azimuth angle of the observed point in the three-dimensional spherical coordinate system.

[0120] Furthermore, the S5 specifically includes the following steps:

[0121] S51. Based on the calculated isotropic surface reflection depolarization coefficient P in the upper hemisphere space 1+ and the anisotropic surface reflection depolarization coefficient P in the upper hemisphere space 2+ , we can get the surface reflection depolarization coefficient P in the upper hemisphere space with the observation zenith angle θ∈[0°,90°] + ;

[0122] S52. Based on the calculated isotropic surface reflection depolarization coefficient P in the lower hemisphere space 1-and the anisotropic surface reflection depolarization coefficient P in the lower hemisphere space 2- , we can get the surface reflection depolarization coefficient P in the lower hemisphere space with the observation zenith angle θ∈[90°,180°] - ;

[0123] S53. The surface reflection depolarization coefficient P in the upper hemisphere space according to the observed zenith angle θ∈[0°,90°] + and the surface reflection depolarization coefficient P in the lower hemisphere space with the observation zenith angle θ∈[90°,180°] - , and obtain the surface reflection depolarization coefficient P;

[0124] In the above S51, the isotropic surface reflection depolarization coefficient P in the upper hemisphere space 1+ It is expressed as:

[0125] P 1+ =(cos(Aθ s )) B ·e -Cρ* +(1-(cos(Aθ s )) B )

[0126] ρ*=ρ·e -Kh

[0127] Among them, A is the first empirical coefficient, B is the second empirical coefficient, C is the third empirical coefficient, ρ is the surface reflectivity, K is the eleventh empirical coefficient, h is the observation height, θ s is the solar zenith angle, ρ * is the height equivalent surface reflectivity;

[0128] Anisotropic surface reflection depolarization coefficient P in the upper hemisphere space 2+ It is expressed as:

[0129]

[0130] Wherein, D is the fourth empirical coefficient, E is the fifth empirical coefficient, F is the sixth empirical coefficient, G is the seventh empirical coefficient, and sec is the secant function;

[0131] In the S52, the isotropic surface reflection depolarization coefficient P in the lower hemisphere space 1- It is expressed as:

[0132] P 1- =P 1+ ·P 2+ (θ=90°)

[0133] Anisotropic surface reflection depolarization coefficient P in the lower hemisphere space 2- It is expressed as:

[0134] P 2- =[Ψ·(cos(θ)+1) (Λ+1) +(1-Ψ)]

[0135]

[0136] Among them, H is the eighth empirical coefficient, I is the ninth empirical coefficient, J is the tenth empirical coefficient, and a i is the twelfth empirical coefficient, b i is the thirteenth empirical coefficient, c i is the fourteenth empirical coefficient, d i is the fifteenth empirical coefficient, Ψ is the first empirical function, Λ is the second empirical function, and the empirical coefficients are all obtained based on the known observation wavelength;

[0137] In S53, the surface reflection depolarization coefficient P is expressed as:

[0138]

[0139] Further, in S6, the sky polarization mode DoP is expressed as:

[0140] DoP=DoP B ·P

[0141] Specifically, refer to Figure 3 , X c is the horizontal axis of the three-dimensional space coordinate system, Y c is the vertical axis of the three-dimensional space coordinate system, Z c is the vertical axis of the three-dimensional space coordinate system, S is the projection point on the celestial surface, zenith is the zenith, observed point is the observation point, and Sun is the sun;

[0142] refer to Figure 4 , three-dimensional space coordinate system O a -x a y a z a The observer is the origin and the direction of the sun is y. a Axis direction, z a The axis is constructed in the plumb direction; the plane sun direction coordinate system O i -x i y i The origin is the celestial apex of the observer's celestial sphere, and the direction of the sun is y. i Direction construction, and keep x i O i y i Plane and x a O a y a Plane parallel, x iis the x-axis of the plane sun direction coordinate system, x a is the x-axis of the three-dimensional space coordinate system, y i is the y-axis of the plane sun direction coordinate system, y a is the y-axis of the three-dimensional space coordinate system, z a is the z-axis of the three-dimensional space coordinate system, O i is the origin of the plane sun direction coordinate system, O a is the origin of the three-dimensional space coordinate system, Re[ζ] is the real part of the complex coordinate of the observed point in the plane solar direction coordinate system, Im[ζ] is the imaginary part of the complex coordinate of the observed point in the plane solar direction coordinate system, β is the observation azimuth of the observed point in the three-dimensional space, and φ is the polar angle of the observed point in the plane solar direction coordinate system.

[0143] Although the present invention has been described according to a limited number of embodiments, it will be apparent to those skilled in the art, with the benefit of the above description, that other embodiments may be envisioned within the scope of the invention thus described. In addition, it should be noted that the language used in this specification is selected primarily for readability and teaching purposes, rather than for explaining or defining the subject matter of the present invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the present invention is illustrative, not restrictive, with respect to the scope of the present invention, which is defined by the appended claims.

Claims

1. A method for modeling sky polarization patterns taking into account the influence of surface reflection depolarization, characterized in that: The following steps are involved: S1. Calculate the sun's zenith angle and azimuth angle based on the geographical location and observation time; S2. Establish a plane sun direction coordinate system, and calculate the ideal sky polarization degree according to the Berry model on the plane sun direction coordinate system; S3. Establish a three-dimensional spherical coordinate system, and map the polarization degree diagram to a three-dimensional spherical surface according to the stereographic projection coordinate transformation relationship; S4. Acquire the surface reflectance of the observation location in combination with the spectral database; S5. Calculate the depolarization coefficient of the entire celestial surface reflection by combining the observation altitude, observation wavelength, solar zenith angle and surface reflectivity; S6. Multiply the ideal sky polarization degree by the surface reflection depolarization coefficient to obtain the sky polarization mode that takes into account the influence of surface reflection depolarization.

2. A method for modeling sky polarization patterns taking into account the influence of surface reflection depolarization according to claim 1, characterized in that: In S1, the azimuth angle of the sun is A s It is expressed as: Among them, δ is the right ascension of the sun, h s is the altitude angle of the sun, φ o is the geographical latitude of the observation location; The sun's altitude angle h s It is expressed as: born s =sinφ o sinδ+cosφ o cosδcosω Where, ω is the solar hour angle; The solar hour angle ω is expressed as: ω=η o +(UT1+E)×15-180 Among them, η o is the geographical longitude of the observation location, E is the difference between true solar time and mean solar time, and UT1 is Greenwich local time; The sun's zenith angle θ s It is expressed as: i s =90°-h s 。 3. A method for modeling sky polarization patterns taking into account the influence of surface reflection depolarization according to claim 2, characterized in that: In S2, the Berry model is established on a plane solar direction coordinate system, and the complex coordinate of the sun in the plane solar direction coordinate system is ξ, ξ = iy s , where i is the imaginary unit, y s The projection coordinates of the sun on the y-axis of the plane solar direction coordinate system are obtained, and the complex coordinates of the four polarization neutral points in the sky are obtained; The complex coordinate v1 of the first polarization neutral point is expressed as: Among them, A0 represents the parameter of polarization neutral point splitting degree, ζ + is the complex coordinate of the first polarization neutral point in the Berry model; The complex coordinate v2 of the second polarization neutral point is expressed as: Among them, - is the complex coordinate of the second polarization neutral point in the Berry model; The complex coordinate v3 of the third polarization neutral point is expressed as: in, is the complex conjugate value of the complex coordinates of the first polarization neutral point in the Berry model; The complex coordinate v4 of the fourth polarization neutral point is expressed as: in, is the complex conjugate value of the complex coordinate of the second polarization neutral point in the Berry model; The sky polarization intensity ω(ζ) at the complex coordinates of any observed point ζ in the plane solar direction coordinate system is expressed as: ζ=rexp(iφ) Where r is the polar diameter of the observed point ζ on the complex plane, φ is the polar angle of the observation point on the complex plane, i is the imaginary unit, exp is the natural exponential function, and according to the Berry model, the ideal sky polarization DoP is obtained B .

4. The method for modeling sky polarization patterns taking into account the influence of surface reflection depolarization according to claim 3, characterized in that: In S3, the stereographic projection coordinate transformation relationship is the correspondence between the point (r, φ) in the plane sun direction coordinate system and the point (R, α, β) in the three-dimensional spherical coordinate system; The corresponding relationship is expressed as: R≡1 β=φ Among them, R is the distance between the observed point and the center of the sphere in the three-dimensional spherical coordinate system, α is the elevation angle of the observed point in the three-dimensional spherical coordinate system, and β is the azimuth angle of the observed point in the three-dimensional spherical coordinate system.

5. The method for modeling sky polarization patterns taking into account the influence of surface reflection depolarization according to claim 4, characterized in that: The S5 specifically includes the following steps: S51. Based on the calculated isotropic surface reflection depolarization coefficient P in the upper hemisphere space 1+ and the anisotropic surface reflection depolarization coefficient P in the upper hemisphere space 2+ , we can get the surface reflection depolarization coefficient P in the upper hemisphere space with the observation zenith angle θ∈[0°,90°] + ; S52. Based on the calculated isotropic surface reflection depolarization coefficient P in the lower hemisphere space 1- and the anisotropic surface reflection depolarization coefficient P in the lower hemisphere space 2- , we can get the surface reflection depolarization coefficient P in the lower hemisphere space with the observation zenith angle θ∈[90°,180°] - ; S53. The surface reflection depolarization coefficient P in the upper hemisphere space according to the observed zenith angle θ∈[0°,90°] + and the surface reflection depolarization coefficient P in the lower hemisphere space with the observation zenith angle θ∈[90°,180°] - , and obtain the surface reflection depolarization coefficient P; In the above S51, the isotropic surface reflection depolarization coefficient P in the upper hemisphere space 1+ It is expressed as: R 1+ =(cos(Aθ) s )) B ·e -Cρ* +(1-(cos(Aθ) s )) B ) p*=p·e -Kh Among them, A is the first empirical coefficient, B is the second empirical coefficient, C is the third empirical coefficient, ρ is the surface reflectivity, K is the eleventh empirical coefficient, h is the observation height, θ s is the solar zenith angle, ρ * is the height equivalent surface reflectivity; Anisotropic surface reflection depolarization coefficient P in the upper hemisphere space 2+ It is expressed as: Wherein, D is the fourth empirical coefficient, E is the fifth empirical coefficient, F is the sixth empirical coefficient, G is the seventh empirical coefficient, and sec is the secant function; In the S52, the isotropic surface reflection depolarization coefficient P in the lower hemisphere space 1- It is expressed as: R 1- =P 1+ ·P 2+ (θ=90°) Anisotropic surface reflection depolarization coefficient P in the lower hemisphere space 2- It is expressed as: R 2- =[Ψ·(cos(θ)+1) (Λ+1) +(1-Ψ)] Among them, H is the eighth empirical coefficient, I is the ninth empirical coefficient, J is the tenth empirical coefficient, and a i is the twelfth empirical coefficient, b i is the thirteenth empirical coefficient, c i is the fourteenth empirical coefficient, d i is the fifteenth empirical coefficient, Ψ is the first empirical function, Λ is the second empirical function, and the empirical coefficients are all obtained based on the known observation wavelength; In S53, the surface reflection depolarization coefficient P is expressed as:

6. The method for modeling sky polarization patterns taking into account the influence of surface reflection depolarization according to claim 5, characterized in that: In S6, the sky polarization pattern DoP is expressed as: DoP=DoP B ·Ρ。

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