Polarized light orientation error compensation method

Abstract

The invention discloses a polarized light orientation error compensation method, which comprises the following steps: acquiring an atmospheric polarization image, and constructing a polarization vector non-orthogonal error angle model; solving the polarization vector non-orthogonal error angle model to obtain a non-orthogonal error angle of each observation point in the atmospheric polarization image; and calculating to obtain an E vector of each observation point based on the non-orthogonal error angle, and obtaining a course angle of the carrier. The method is applied to the field of polarized light navigation, the non-orthogonal error is quantitatively introduced into the construction process of the polarization vector non-orthogonal error angle model, and the polarization vector non-orthogonal error is compensated based on the prior information according to the characteristic that the non-orthogonal error angle changes slowly in a short time, so that the polarization vector non-orthogonal error is compensated. Therefore, the non-orthogonal error angle of the observation point in the atmospheric polarization image is estimated, the influence of the non-orthogonal error angle on the orientation result can be better compensated, and the method can be effectively suitable for cloudy weather orientation with the large non-orthogonal error angle.

Description

Technical Field

[0001] The invention relates to the technical field of polarized light navigation, in particular to a method for compensating for polarized light orientation errors. Background Art

[0002] Accurate positioning information is the basis for autonomous navigation of long-flight unmanned platforms. However, in the case of satellite stoppage or complex electromagnetic interference environment, the existing inertial navigation has error accumulation and geomagnetic navigation is easily interfered, which cannot meet the requirements of high-precision navigation of unmanned platforms.

[0003] During the propagation process, sunlight is absorbed and scattered by atmospheric particles to produce polarized light. A large amount of polarized light converges in the sky to form an atmospheric polarization pattern with a certain distribution pattern. The atmospheric polarization pattern contains directional information. Based on the geometric property that the E vector of polarized light is perpendicular to the scattering surface in the Rayleigh scattering model, the carrier azimuth can be estimated by measuring the atmospheric polarization information, which is the conventional orientation method based on the orthogonality of the polarization vector. Although the orientation method based on the orthogonality of the polarization vector can effectively improve the orientation accuracy in sunny days with obstructions, few clouds and cloudy weather, it is not effective for cloudy weather. The reason is that the polarization degree is not clearly distinguished in cloudy weather. Even if there are a few Rayleigh points, it is difficult to screen them. The E vector of the non-Rayleigh point is no longer perpendicular to the scattering surface, but there is an angle between it and the E vector of the Rayleigh point, which is called the non-orthogonal error angle of the polarization vector. In addition, the non-orthogonal error angle of the non-Rayleigh point is large in cloudy weather. If the orientation method based on the orthogonality of the polarization vector continues to be used, a large orientation error will be introduced. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for compensating polarized light orientation errors, which compensates for non-orthogonal error angles in the process of calculating the heading angle information of the carrier, and is effectively suitable for orientation in cloudy weather with large non-orthogonal error angles.

[0005] To achieve the above object, the present invention provides a method for compensating polarized light orientation error, comprising the following steps:

[0006] Step 1, obtaining an atmospheric polarization image and constructing a polarization vector non-orthogonal error angle model;

[0007] Step 2, solving the polarization vector non-orthogonal error angle model to obtain the non-orthogonal error angle of each observation point in the atmospheric polarization image;

[0008] Step 3, based on the non-orthogonal error angle calculation, the E vector of each observation point is obtained, and the sun direction vector is obtained according to the E vector of each observation point, and the heading angle of the carrier is obtained.

[0009] In one embodiment, in step 1, the process of constructing the polarization vector non-orthogonal error angle model is:

[0010] Decompose the E vector e of the observation point into the coordinate system composed of the sun direction vector s axis, the observation direction vector v axis and the orthogonal axes composed of v×s:

[0011] e=r1·s+r2·v+r3·v×s

[0012] Among them, r1=sinη / / sinτ, r2=-sinη / / tanτ, r3=-cosη / / sinτ are the modulus lengths of the E vector e of the observation point on the three axes respectively, η is the non-orthogonal error angle of the observation point, and τ is the scattering angle;

[0013] Projecting the E vector e of the observation point to the optical compass coordinate system, we have:

[0014] e c =r1·s c +r2·v c +r3·v c ×s c

[0015] Among them, e c is the projection of the E vector e of the observation point on the optical compass coordinate system, s c is the projection of the sun direction vector on the optical compass coordinate system, v c is the projection of the observation direction vector on the optical compass coordinate system;

[0016] Let f(η) = r1·s c +r2·v c +r3·v c ×s c -e c As the objective function, the polarization vector non-orthogonal error angle model is

[0017] In one embodiment, the projection of the E vector e of the observation point on the optical compass coordinate system is specifically:

[0018]

[0019] is the transformation matrix from the observation point coordinate system to the optical compass coordinate system, expressed as:

[0020]

[0021] Among them, α v is the azimuth of the observation point in the optical compass coordinate system, γ v is the zenith angle of the observation point in the optical compass coordinate system, α v , γ v That is the observation information of the observation point;

[0022] e v is the projection of the E vector e of the observation point on the observation point coordinate system, expressed as:

[0023]

[0024] Where φ is the polarization angle of the observation point.

[0025] In one embodiment, the projection of the sun direction vector on the optical compass coordinate system is specifically:

[0026]

[0027] is the transformation matrix from the carrier coordinate system to the optical compass coordinate system, expressed as:

[0028]

[0029] is the transformation matrix from the navigation coordinate system to the optical compass coordinate system, expressed as:

[0030]

[0031] Among them, r0, θ0, Ψ0 are respectively provided by other sensors for the carrier roll angle, pitch angle and heading angle;

[0032] s n is the sun direction vector in the navigation coordinate system, expressed as:

[0033]

[0034] Where T is the transpose of the matrix, is the azimuth of the sun direction vector in the navigation coordinate system, is the altitude angle of the sun direction vector in the navigation coordinate system. When the time and geographical location are known, It can be obtained through the solar ephemeris.

[0035] In one embodiment, the projection of the observation direction vector on the optical compass coordinate system is specifically:

[0036] v c =[siny v ·cosα v siny v ·sinα v -cosγ v ] T

[0037] Where T is the transpose of the matrix.

[0038] In one of the embodiments, in step 2, the polarization vector non-orthogonal error angle model is solved based on the interior point method.

[0039] In one embodiment, step 3 is specifically:

[0040] Decompose the E vector e of the observation point into the coordinate system composed of the sun direction vector s axis, the observation direction vector v axis and the orthogonal axes composed of v×s:

[0041] e=r1·s+r2·v+r3·v×s

[0042] Among them, r1=sinη / / sinτ, r2=-sinη / / tanτ, r3=-cosη / / sinτ are the modulus lengths of the E vector e of the observation point on the three axes respectively, η is the non-orthogonal error angle of the observation point, and τ is the scattering angle;

[0043] Projecting the E vector e of the observation point to the optical compass coordinate system, we have:

[0044] e c =r1·s c +r2·v c +r3·v c ×s c

[0045] Further written as:

[0046] e c -r2·v c =r1·s c +r3·[v c ×]s c

[0047] Among them, e c is the projection of the E vector e of the observation point on the optical compass coordinate system, s c is the projection of the sun direction vector on the optical compass coordinate system, v c is the projection of the observation direction vector on the optical compass coordinate system, [v c ×] is v c The antisymmetric matrix of ;

[0048] Because there are:

[0049]

[0050] in, is the transformation matrix from the carrier coordinate system to the optical compass coordinate system, is the transformation matrix from the navigation coordinate system to the optical compass coordinate system, s n is the sun direction vector in the navigation coordinate system;

[0051] Then c for:

[0052]

[0053]

[0054] in, x c is the intermediate parameter, r, θ, Ψ are the actual carrier roll angle, pitch angle and heading angle respectively, is the azimuth of the sun direction vector in the navigation coordinate system, is the altitude angle of the sun direction vector in the navigation coordinate system;

[0055] Further we get:

[0056]

[0057] Among them, E3 is the unit matrix;

[0058] Simplifying gives:

[0059]

[0060] P=(r1·E3+r3·[v c ×])

[0061] Among them, P is the intermediate parameter;

[0062] So we have:

[0063]

[0064] Then the actual heading angle of the carrier is:

[0065]

[0066] or

[0067]

[0068] Among them, x c (1), x c (2) Divided into vector x c The first and second elements in α s is the solar azimuth angle, and π is the ambiguity of the polarized light orientation.

[0069] Compared with the prior art, the present invention has the following beneficial technical effects:

[0070] The present invention constructs a polarization vector non-orthogonal error angle model, and quantitatively introduces the polarization vector non-orthogonal error caused by multiple scattering in cloudy weather into the model construction process. According to the characteristic that the non-orthogonal error angle changes slowly in a short period of time, the polarization vector non-orthogonal error is compensated based on prior information, thereby estimating the non-orthogonal error angle of the observation point in the atmospheric polarization image, which can better compensate for the influence of the non-orthogonal error angle on the orientation result, and is effectively suitable for cloudy weather orientation with a large non-orthogonal error angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0072] Figure 1 is a flow chart of a method for compensating for polarized light orientation errors in an embodiment of the present invention;

[0073] Figure 2 Schematic diagram of the scattering process of sunlight in the sky in an embodiment of the present invention;

[0074] Figure 3 Schematic diagram of non-orthogonal error angle of polarization vectors in an embodiment of the present invention;

[0075] Figure 4 Schematic diagram of the first orthogonal relationship of vibration vectors in an embodiment of the present invention;

[0076] Figure 5 Schematic diagram of the second orthogonal relationship of vibration vectors in an embodiment of the present invention.

[0077] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0078] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0079] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0080] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0081] This embodiment discloses a method for compensating for polarized light orientation errors, which mainly estimates the non-orthogonal error angle of the observation point through a polarization vector non-orthogonal error angle model, and then compensates for the estimated non-orthogonal error angle during the orientation process, thereby realizing carrier positioning. By quantitatively introducing the non-orthogonal error of the polarization vector caused by multiple scattering in cloudy weather into the model construction process, the non-orthogonal error of the polarization vector is compensated based on prior information according to the characteristic that the non-orthogonal error angle changes slowly in a short period of time, thereby estimating the non-orthogonal error angle of the observation point in the atmospheric polarization image, which can better compensate for the impact of the non-orthogonal error angle on the orientation result, and can be effectively suitable for cloudy weather orientation with a large non-orthogonal error angle.

[0082] refer to Figure 1 In this embodiment, the polarization light orientation error compensation method specifically includes the following steps:

[0083] Step 1, obtaining an atmospheric polarization image and constructing a polarization vector non-orthogonal error angle model;

[0084] Step 2, solving the polarization vector non-orthogonal error angle model to obtain the non-orthogonal error angle of each observation point in the atmospheric polarization image;

[0085] Step 3, based on the non-orthogonal error angle calculation, the E vector of each observation point is obtained, and the sun direction vector is obtained according to the E vector of each observation point, and the heading angle of the carrier is obtained.

[0086] refer to Figure 2 Schematic diagram of the scattering process of sunlight in the sky, where O c represents the observer on the ground, V represents the observation point in the sky, S represents the sun, Z represents the zenith, N represents the geographic north, τ represents the scattering angle, γ s , α s Represent the solar zenith angle and azimuth respectively, φ represents the polarization angle of the observation point, α v represents the azimuth of the observation point, γ v , α vRepresents the zenith angle and azimuth angle of the observation point V in the polarized light compass coordinate system respectively.

[0087] In this embodiment, the right-front-upper coordinate system is defined as the polarized light compass coordinate system (hereinafter referred to as the "C system"), X c Axis and Y c The axes point to the horizontal and vertical axes of the polarized light compass respectively, Z c The axis is the optical axis direction of the polarized light compass. After leveling, the Z c The axis points to the zenith. The north-east-earth coordinate system is defined as the navigation coordinate system (hereinafter referred to as the "n system"), and O n -X n Y n Z n Indicates that O n With O c coincide, Figure 2 For the sake of simplicity, Y is omitted. n Axis and Z n Axis, X n The axis direction is the geographic north. Figure 2 The front-right-bottom coordinate system is defined as the carrier coordinate system (hereinafter referred to as the "b system"), and O b -X b Y b Z b To represent, where O b With O c coincide, Figure 2 For the sake of simplicity, Y is omitted. b Axis and Z b Axis, the heading angle Ψ of the carrier is X b The angle between the axis and N. Define O v -X v Y v Z v is the observation point coordinate system (hereinafter referred to as “v system”), Z v The axis points to the direction of the observation point, X v The axis is located in the observation plane ΔO v In VV′, Y v The axis is known from the right-hand rule. Figure 2 For the sake of simplicity, Y is omitted. v Axis. e is the unit vector of the vibration direction of the polarized light E vector at the observation point V, v is the unit vector of the observation direction, and s is the unit vector in the direction of the sun.

[0088] refer to Figure 3 is a schematic diagram of the non-orthogonal error angle of the polarization vector, where the coordinate system is set and Figure 2 In the figure, the polarized light E vector e′ at the Rayleigh point is perpendicular to the scattering plane ΔSO c Ov , the polarized light E vector e at the non-Rayleigh point is not perpendicular to the scattering plane ΔSO c O v Since light is a transverse wave, there are always e′ and e perpendicular to the incident light direction vector v, so there is a polarization vector non-orthogonal error angle between e and e′, which is recorded as η in this embodiment.

[0089] refer to Figure 4 , Figure 5 Regardless of whether the polarization vectors have an orthogonal relationship, e can be represented by the vector consisting of the incident light direction vector v, the sun direction vector s, and v×s. Therefore, the specific construction process of the polarization vector non-orthogonal error angle model in this embodiment is:

[0090] Step 101, decompose the E vector e of the observation point into a coordinate system consisting of the sun direction vector s axis, the observation direction vector v axis and the orthogonal axes consisting of v×s, as follows:

[0091] e=r1·s+r2·v+r3·v×s (1)

[0092] Among them, r1=sinη / / sinτ, r2=-sinη / / tanτ, r3=-cosη / / sinτ are the modulus lengths of the E vector e of the observation point on the three axes respectively;

[0093] The calculation process of the scattering angle τ is:

[0094]

[0095] Among them, s c is the projection of the sun direction vector on the optical compass coordinate system, v c is the projection of the observation direction vector on the optical compass coordinate system, and T is the transpose of the matrix;

[0096] Ideally, the non-orthogonal error angle η of the Rayleigh point is 0. At this time, equation (1) degenerates into a polarization vector orthogonal model, that is, e = r3·v×s;

[0097] Step 102, project the E vector e of the observation point to the optical compass coordinate system, then:

[0098] e c =r1·s c +r2·v c +r3·v c ×s c (3)

[0099] Among them, e c is the projection of the E vector e of the observation point on the optical compass coordinate system;

[0100] Step 103, let f(η)=r1·s c +r2·v c +r3·v c ×s c -e c is the objective function. Theoretically, f(η)=0. However, due to the existence of the non-orthogonal error angle of the polarization vector, usually f(η)≠0. Therefore, the final non-orthogonal error angle model of the polarization vector is:

[0101]

[0102] In this embodiment, since the non-orthogonal error angle changes slowly in a short time, in the process of constructing the polarization vector non-orthogonal error angle model, the projection s of the sun direction vector on the optical compass coordinate system can be calculated by prior information. c , the projection v of the observation direction vector on the optical compass coordinate system c And the projection e of the E vector of the observation point on the optical compass coordinate system c .

[0103] In this embodiment, the specific calculation process of the projection of the E vector e of the observation point on the optical compass coordinate system is:

[0104]

[0105] is the conversion matrix from v system to c system, expressed as:

[0106]

[0107] Zenith angle γ of the observation point in the c system v and azimuth α v Specifically:

[0108]

[0109] Among them, (x v ,y v ) is the coordinate of the observation point in the atmospheric polarization image, (x c ,y c ) is the coordinate of the center point of the atmospheric polarization image, f c is the focal length of the polarized light compass obtained through calibration;

[0110] e v is the projection of the E vector e of the observation point on the v system, expressed as:

[0111]

[0112] Among them, φ is the polarization angle of the observation point, that is, the prior information.

[0113] In this embodiment, in the process of constructing the polarization vector non-orthogonal error angle model, the polarization angle of the observation point can be calculated using the Stokes vector method. The Stokes vector contains four parameters S0 = [S1 S2 S3 S4], where S1 represents the total light intensity, S2 is the light intensity difference in the 0° and 90° directions, S3 is the light intensity difference in the 45° and 135° directions, and S4 is the circular polarization component. The light intensity of the polarized light after passing through the polarizer is:

[0114]

[0115] Where θ1 is the polarization angle, is the angle between the sensor polarization direction and the system optical axis;

[0116] Since there are very few circular polarization components in nature, the S4 component is generally omitted in actual calculations, and the simplified Stokes intensity equation is obtained as follows:

[0117]

[0118] When the polarization angle θ1 is 0°, 45°, and 90° respectively, the Stokes parameter of each pixel on the image is:

[0119]

[0120] Without considering circularly polarized light, the polarization angle of each pixel is:

[0121]

[0122] In this embodiment, the specific calculation process of the projection of the sun direction vector on the optical compass coordinate system is:

[0123]

[0124] is the transformation matrix from b system to c system, expressed as:

[0125]

[0126] is the conversion matrix from n system to c system, expressed as:

[0127]

[0128] Among them, r0, θ0, Ψ0 are respectively provided by other sensors (such as satellite dual antennas) to provide the carrier roll angle, pitch angle and heading angle, i.e., prior information;

[0129] s n is the sun direction vector in the navigation coordinate system, expressed as:

[0130]

[0131] in, is the azimuth of the sun direction vector in the navigation coordinate system, is the altitude angle of the sun direction vector in the navigation coordinate system. When the time and geographical location are known, It can be obtained through the solar ephemeris, that is, This is also prior information.

[0132] In this embodiment, the specific calculation process of the projection of the observation direction vector on the optical compass coordinate system is:

[0133] v c =[sinγ v ·cosα v sinγ v ·sinα v -cosγ v ] T (18)

[0134] After the polarization vector non-orthogonal error angle model is constructed, the observation information of each observation point in the atmospheric polarization image is substituted into the polarization vector non-orthogonal error angle model, and the polarization vector non-orthogonal error angle model is solved by combining a series of prior information, so that the non-orthogonal error angle of each observation point can be estimated. According to formula (4), the problem of solving the non-orthogonal error angle can be transformed into a nonlinear programming problem with boundary constraints. Therefore, in the specific implementation process of solving the polarization vector non-orthogonal error angle model in step 2, the interior point method is used to solve the nonlinear optimization problem, which has the advantages of low computational complexity and strong robustness.

[0135] In the specific implementation process, the E vector of each observation point is calculated based on the non-orthogonal error angle, and the sun direction vector is obtained according to the E vector of each observation point, and the process of obtaining the heading angle of the carrier is as follows:

[0136] First, substitute the non-orthogonal error angles of each observation point estimated in step 2 into r1, r2, and r3 in equation (3), and then write equation (3) as:

[0137] e c -r2·v c =r1·s c +r3·[v c ×]s c (19)

[0138] Among them, [v c ×] is v c The antisymmetric matrix of ;

[0139] Secondly, based on equation (14), the projection s of the sun direction vector on the optical compass coordinate system can be expressed as c Written as:

[0140]

[0141] in, x c are intermediate parameters, r, θ, Ψ are the actual carrier roll angle, pitch angle and heading angle respectively;

[0142] Then, formula (19) can be simplified as:

[0143]

[0144] Among them, E3 is the unit matrix;

[0145] Formula (21) can be simplified as:

[0146]

[0147] in:

[0148] P=(r1·E3+r3·[v c ×]) (25)

[0149] Among them, P is the intermediate parameter;

[0150] So we have:

[0151]

[0152] At the same time and place, different observation points correspond to different E vectors and different observation direction vectors, but the corresponding sun direction vector is unified. Therefore, the projection s of the sun direction vector on the c system can be obtained by using the Lagrange multiplier method to solve the simultaneous equations of all observation points. c , combined with equations (20)-(22), the actual heading angle of the carrier can be obtained as:

[0153]

[0154] or

[0155]

[0156] Among them, x c (1), x c (2) Divided into vector x c The first and second elements in α s is the solar azimuth angle, and π is the ambiguity of the polarized light orientation.

[0157] In a specific implementation, the ambiguity π of the polarized light orientation can be removed by the quadrant position of the solar meridian projection or the heading angle difference between adjacent frames.

[0158] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for compensating polarized light orientation error, characterized in that: The steps include: Step 1, obtaining an atmospheric polarization image and constructing a polarization vector non-orthogonal error angle model; Step 2, solving the polarization vector non-orthogonal error angle model to obtain the non-orthogonal error angle of each observation point in the atmospheric polarization image; Step 3, based on the non-orthogonal error angle calculation, the E vector of each observation point is obtained, and the sun direction vector is obtained according to the E vector of each observation point, and the heading angle of the carrier is obtained.

2. The polarization light orientation error compensation method according to claim 1, characterized in that: In step 1, the construction process of the polarization vector non-orthogonal error angle model is: Decompose the E vector e of the observation point into the coordinate system composed of the sun direction vector s axis, the observation direction vector v axis and the orthogonal axes composed of v×s: e=r1·s+r2·v+r3·v×s Among them, r1 = sinη / sinτ, r2 = -sinη / tanτ, r3 = -cosη / sinτ are the modulus lengths of the E vector e of the observation point on the three axes, η is the non-orthogonal error angle of the observation point, and τ is the scattering angle; Projecting the E vector e of the observation point to the optical compass coordinate system, we have: yes c =r1·s c +r2·v c +r3·v c ×s c Among them, e c is the projection of the E vector e of the observation point on the optical compass coordinate system, s c is the projection of the sun direction vector on the optical compass coordinate system, v c is the projection of the observation direction vector on the optical compass coordinate system; Let f(η) = r1·s c +r2·v c +r3·v c ×s c -e c As the objective function, the polarization vector non-orthogonal error angle model is 3. The polarization light orientation error compensation method according to claim 2, characterized in that: The projection of the E vector e of the observation point on the optical compass coordinate system is specifically: is the transformation matrix from the observation point coordinate system to the optical compass coordinate system, expressed as: Among them, α v is the azimuth of the observation point in the optical compass coordinate system, γ v is the zenith angle of the observation point in the optical compass coordinate system; e v is the projection of the E vector e of the observation point on the observation point coordinate system, expressed as: Where φ is the polarization angle of the observation point.

4. The method for compensating polarized light orientation error according to claim 2, characterized in that: The projection of the sun direction vector on the optical compass coordinate system is specifically: is the transformation matrix from the carrier coordinate system to the optical compass coordinate system, expressed as: is the transformation matrix from the navigation coordinate system to the optical compass coordinate system, expressed as: Among them, r0, θ0, Ψ0 are respectively provided by other sensors for the carrier roll angle, pitch angle and heading angle; s n is the sun direction vector in the navigation coordinate system, expressed as: Where T is the transpose of the matrix, is the azimuth of the sun direction vector in the navigation coordinate system, is the altitude angle of the sun direction vector in the navigation coordinate system.

5. The method for compensating polarized light orientation error according to claim 2, characterized in that: The projection of the observation direction vector on the optical compass coordinate system is specifically: v c =[sinγ v ·cosα v sinγ v ·sinα v -cosγ v ] T Among them, T is the transpose of the matrix, α v is the azimuth of the observation point in the optical compass coordinate system, γ v is the zenith angle of the observation point in the optical compass coordinate system.

6. The method for compensating polarized light orientation error according to any one of claims 1 to 5, characterized in that: In step 2, the polarization vector non-orthogonal error angle model is solved based on the interior point method.

7. The method for compensating polarized light orientation error according to any one of claims 1 to 5, characterized in that: Step 3 is as follows: Decompose the E vector e of the observation point into the coordinate system composed of the sun direction vector s axis, the observation direction vector v axis and the orthogonal axes composed of v×s: e=r1·s+r2·v+r3·v×s Among them, r1 = sinη / sinτ, r2 = -sinη / tanτ, r3 = -cosη / sinτ are the modulus lengths of the E vector e of the observation point on the three axes, η is the non-orthogonal error angle of the observation point, and τ is the scattering angle; Projecting the E vector e of the observation point to the optical compass coordinate system, we have: yes c =r1·s c +r2·v c +r3·v c ×s c Further written as: yes c -r2·v c =r1·s c +r3·[v c ×]s c Among them, e c is the projection of the E vector e of the observation point on the optical compass coordinate system, s c is the projection of the sun direction vector on the optical compass coordinate system, v c is the projection of the observation direction vector on the optical compass coordinate system, [v c ×] is v c The antisymmetric matrix of ; Because there are: in, is the transformation matrix from the carrier coordinate system to the optical compass coordinate system, is the transformation matrix from the navigation coordinate system to the optical compass coordinate system, s n is the sun direction vector in the navigation coordinate system; Then c for: in, x c is the intermediate parameter, r, θ, Ψ are the actual carrier roll angle, pitch angle and heading angle respectively, is the azimuth of the sun direction vector in the navigation coordinate system, is the altitude angle of the sun direction vector in the navigation coordinate system; Further we get: Among them, E3 is the unit matrix; Simplifying gives: P=(r1·E3+r3·[v c ×]) Among them, P is the intermediate parameter; So we have: Then the actual heading angle of the carrier is: or Among them, x c (1), x c (2) Divided into vector x c The first and second elements in α s is the solar azimuth angle, and π is the ambiguity of the polarized light orientation.

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