Course angle extraction method, system and device and medium

Abstract

The invention discloses a course angle extraction method, system and device and a medium. The course angle extraction method comprises the steps that the polarization angle and the polarization degree of underwater polarized light are calculated according to a multi-channel least square method; calculating a light vector in a horizontal coordinate system according to the polarization angle and the polarization degree of the underwater polarized light; and calculating a solar azimuth angle in a horizontal coordinate system according to the light vector, and extracting a course angle according to a solar azimuth angle in a navigation coordinate system and the solar azimuth angle in the horizontal coordinate system. The embodiment of the invention can efficiently and accurately extract the course angle information, and can be widely applied to the technical field of navigation.

Description

Technical Field

[0001] The present invention relates to the field of navigation technology, and in particular to a method, system, device and medium for extracting a heading angle. Background Art

[0002] PL (Polarized Light) navigation has been widely used in the fields of UAVs and autonomous unmanned underwater vehicles (AUVs). The purpose of measuring PL light intensity is to calculate the accurate attitude angle. Therefore, the attitude angle solution algorithm is also very important. The research on this type of algorithm is very active. The heading angle calculation method is divided into two types: the solution method under horizontal attitude and the 3D solution method under non-horizontal attitude.

[0003] The extraction of heading angle mainly relies on the distribution diagrams of the angle of polarization (AOP) and degree of polarization (DOP) derived from the PL intensity map. In the actual use environment, there are unfavorable factors such as imaging distortion of wide-angle lenses, waves and ripples on the water surface, floating objects on the water surface, scattering of surface objects and water bodies, etc., and the PL intensity map will deviate far from the ideal situation. Therefore, the heading angle extraction algorithm is required to have strong anti-interference ability in non-horizontal posture. Since the position and attitude angle of the AUV in navigation are constantly changing, the extraction algorithm is required to have good real-time performance and fast calculation speed. The current heading angle extraction algorithm has the disadvantages of insufficient accuracy and insufficient calculation speed. Summary of the invention

[0004] In view of this, in order to solve one of the above problems, an object of an embodiment of the present invention is to provide a heading angle extraction method, system, device and storage medium, which can extract heading angle information efficiently and accurately.

[0005] On the one hand, an embodiment of the present invention provides a method for extracting a heading angle, comprising:

[0006] Calculate the polarization angle and polarization degree of underwater polarized light according to the multi-channel least squares method;

[0007] Calculate the light vector in the horizontal coordinate system according to the polarization angle of the underwater polarized light and the polarization degree;

[0008] The solar azimuth in the horizontal coordinate system is calculated according to the light vector, and the heading angle is extracted according to the solar azimuth in the navigation coordinate system and the solar azimuth in the horizontal coordinate system.

[0009] Optionally, calculating the polarization angle and polarization degree of underwater polarized light according to the multi-channel least squares method includes:

[0010] Establish the corresponding relationship between the intensity of underwater polarized light and the polarization angle and polarization degree of underwater polarized light;

[0011] A plurality of groups of underwater polarized light intensity measurement values ​​are obtained, and a least square method is used to calculate the polarization angle and polarization degree of the underwater polarized light according to the plurality of groups of the light intensity measurement values ​​and the corresponding relationship.

[0012] Optionally, calculating the light vector in the horizontal coordinate system according to the polarization angle and polarization degree of the underwater polarized light includes:

[0013] Determining the polarization angle in the air according to the polarization angle of the underwater polarized light;

[0014] A light vector in a horizontal coordinate system is calculated according to the polarization angle in the air and the polarization degree.

[0015] Optionally, calculating the light vector in a horizontal coordinate system according to the polarization angle in the air and the polarization degree includes:

[0016] Determine the e-vector of the light coordinate system according to the polarization angle in the air;

[0017] The e vector of the light coordinate system is converted into an e vector in a horizontal coordinate system, and the light vector in the horizontal coordinate system is calculated according to the e vector in the horizontal coordinate system and the polarization degree.

[0018] Optionally, converting the e-vector of the light coordinate system into an e-vector in a horizontal coordinate system includes:

[0019] Determine the transformation relationship from the light coordinate system to the horizontal coordinate system;

[0020] The e-vector in the light coordinate system is converted into the e-vector in the horizontal coordinate system according to the conversion relationship.

[0021] Optionally, calculating the solar azimuth in a horizontal coordinate system according to the light vector comprises:

[0022] Calculate the projection of the sun vector in the horizontal coordinate system according to the light vector;

[0023] The solar azimuth in the horizontal coordinate system is calculated according to the relationship between the zenith angle and the azimuth in the projection and the solar vector.

[0024] On the other hand, an embodiment of the present invention provides a heading angle extraction system, including:

[0025] The first module is used to calculate the polarization angle and polarization degree of underwater polarized light according to the multi-channel least square method;

[0026] A second module is used to calculate the light vector in the horizontal coordinate system according to the polarization angle of the underwater polarized light and the polarization degree;

[0027] The third module is used to calculate the solar azimuth in the horizontal coordinate system according to the light vector, and extract the heading angle according to the solar azimuth in the navigation coordinate system and the solar azimuth in the horizontal coordinate system.

[0028] On the other hand, an embodiment of the present invention provides a device for extracting a heading angle, comprising:

[0029] at least one processor;

[0030] at least one memory for storing at least one program;

[0031] When the at least one program is executed by the at least one processor, the at least one processor implements the above method.

[0032] On the other hand, an embodiment of the present invention provides a computer-readable storage medium, in which a program executable by a processor is stored. When the program executable by the processor is executed by the processor, it is used to perform the above method.

[0033] On the other hand, an embodiment of the present invention provides a heading angle extraction system, comprising an underwater vehicle and a computer device connected to the underwater vehicle; wherein:

[0034] The underwater vehicle is used to navigate the solar azimuth in the coordinate system;

[0035] The computer device comprises:

[0036] at least one processor;

[0037] at least one memory for storing at least one program;

[0038] When the at least one program is executed by the at least one processor, the at least one processor implements the above method.

[0039] The implementation of the embodiment of the present invention includes the following beneficial effects: in this embodiment, the polarization angle and polarization degree of underwater polarized light are first calculated according to the multi-channel least squares method to improve the calculation accuracy of polarized light, and then the light vector in the horizontal coordinate system is calculated according to the polarization angle and the polarization degree of the underwater polarized light, the light vector is converted to the horizontal coordinate system, and the solar azimuth in the horizontal coordinate system is calculated according to the light vector, and the heading angle is extracted according to the solar azimuth in the navigation coordinate system and the solar azimuth in the horizontal coordinate system. The calculation process is simple and the computing power is reduced, so that the heading angle information can be extracted in real time, efficiently and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a polarization state distribution model of natural light in the atmosphere provided by an embodiment of the present invention;

[0041] Figure 2 is a schematic flow chart of steps of a method for extracting a heading angle provided by an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the principle of light refraction on a water surface provided by an embodiment of the present invention;

[0043] Figure 4 is a structural block diagram of a heading angle extraction system provided by an embodiment of the present invention;

[0044] Figure 5 It is a structural block diagram of a heading angle extraction device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only provided for the convenience of explanation and description, and the order between the steps is not limited in any way. The execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0046] See also Figure 1 , Figure 1 Distribution model of the polarization state of natural light in the atmosphere. Figure 1 e in l is the electric field vector of the atmospheric light wave, Figure 1 The l system in the image is the light coordinate system (X l / Y l / Z l ), h represents the horizontal coordinate system (X h / Y h / Z h ). Figure 1 φ a , β s and They are e l The angle with the local meridian, the azimuth angle of the sun (in the h system) and the zenith angle of the sun (in the h system). The 0° polarizer direction is generally selected as the bow direction of the AUV, that is, the transmission axis of the 0° polarizer is along the bow direction of the AUV. a Calculated from the measured polarized light intensity information. Once solved, ξ can be easily calculated based on the observation vector in the h system.

[0047] like Figure 2 As shown, an embodiment of the present invention provides a method for extracting a heading angle, comprising the following steps:

[0048] S100, calculating the polarization angle and polarization degree of underwater polarized light according to a multi-channel least squares method;

[0049] S200, calculating a light vector in a horizontal coordinate system according to the polarization angle and polarization degree of the underwater polarized light;

[0050] S300, calculating the solar azimuth in the horizontal coordinate system according to the light vector, and extracting the heading angle according to the solar azimuth in the navigation coordinate system and the solar azimuth in the horizontal coordinate system.

[0051] Specifically, the polarization angle and polarization degree of underwater polarized light are calculated according to multiple groups of light intensity values ​​by the least squares method, and then the light vector in the horizontal coordinate system is calculated according to the polarization angle and polarization degree of the underwater polarized light, and the light is converted from the light coordinate system to the horizontal coordinate system. Finally, the solar azimuth in the horizontal coordinate system is calculated according to the light vector, and the heading is extracted according to the solar azimuth in the navigation coordinate system and the solar azimuth in the horizontal coordinate system.

[0052] The solar azimuth angle β in the navigation coordinate system s It can be obtained through the solar ephemeris. The solar azimuth in the horizontal coordinate system is The heading angle Ψ can be determined by the following formula:

[0053]

[0054] Optionally, the polarization angle and polarization degree of underwater polarized light are calculated according to a multi-channel least squares method, including:

[0055] S110, establishing a corresponding relationship between the light intensity of underwater polarized light and the polarization angle and polarization degree of underwater polarized light;

[0056] S120, obtaining several groups of underwater polarized light intensity measurement values, and calculating the polarization angle and polarization degree of the underwater polarized light using a least square method according to the several groups of light intensity measurement values ​​and corresponding relationships.

[0057] Next, we introduce φ w The calculation method of the polarization angle of underwater polarized light, the light intensity measured by the polarization camera or the light intensity response of the CCD each time can be expressed by the following formula:

[0058] f j (Φ w )=KI[1+d w cos(2Φ w -2Φ j )]

[0059] =KId w cos2Φ w cos2φ j +KId w sin2φ w sin2φ j +KI

[0060] In the above formula, fj (φ w )(j=1,2,...,M) is the intensity of polarized light underwater, φ w is the polarization angle of underwater polarized light, K is the gain of the CCD sensor, I is the light intensity, and d w is the degree of polarization, φ j is the angle between the transmission axis of the jth polarization grating and the heading of the carrier. The above formula can be rewritten as:

[0061] f j (φ w )=A 0 cos2φ j +B 0 sin2φ j +A 0

[0062] A in the above formula 0 =KIdwcos2φ w , B 0 =KIdwsin2φ w and C 0 =KI respectively correspond to the first three components of the Stokes vector describing polarized light. Find φ w A minimum of three measurements are required. When the number of measurements is greater than 3, the least squares method can be used to calculate the heading angle. This algorithm can improve reliability and accuracy. According to the least squares principle, we can get:

[0063]

[0064] Where:

[0065]

[0066] M is the number of measurements, find A 0 , B 0 and C 0 Later, it is easy to get φ w and d w . The minimum error is established as the evaluation function. According to the analysis of the optimal theory, it can be known that when the azimuth angles of the light transmission axes of two adjacent polarizers differ by π / 3 during three-channel measurement, the calculated heading angle error is the smallest. In the embodiment of the present invention, a group of 12 channels with angles between the light transmission axis of the polarizer and the bow of the AUV of 0, π / 6, π / 3, π / 2, 2π / 3, 5π / 6, π, 7π / 6, 4π / 3, 3π / 2, 5π / 3, and 11π / 6 are selected for simultaneous exposure and measurement, and then the heading angle is calculated using the least squares method. In this way, even if one or two gratings cause a decrease in the accuracy of polarized light measurement due to reasons such as field of view obstruction, it will not have much impact on the final heading angle solution result.

[0067] Optionally, calculating the light vector in the horizontal coordinate system according to the polarization angle and polarization degree of the underwater polarized light includes:

[0068] S210, determining the polarization angle in the air according to the polarization angle of the underwater polarized light;

[0069] S220: Calculate the light vector in the horizontal coordinate system according to the polarization angle and polarization degree in the air.

[0070] See also Figure 3 , Figure 3 Schematic diagram showing the principle of light refraction on the water surface. To improve the accuracy of heading angle calculation, it is necessary to compensate for the refraction effect of the water surface. The refraction of a polarized light beam incident from air to water includes the bending of the light and a slight rotation of the polarization plane. The refraction process follows Snell's law. The electric field vector E of the light wave can be decomposed into two orthogonal components, one perpendicular to the refraction plane and the other parallel to the refraction plane (the light vector on the water surface and underwater can be decomposed in this way). Denote the vertical component of the incident / refracted optical electric field by Represents the parallel component of the incident / refracted optical electric field. According to Snell's law, the polarization angle in the air and the polarization angle underwater can be calculated: w The relationship between:

[0071] Φ a

[0072] Among them, n a and n w are the refractive indices of air and water, respectively, and their values ​​are: n a =1,n w =1.33.

[0073] Then, the light vector in the horizontal coordinate system is calculated according to the polarization angle and polarization degree in the air in combination with the Snell window.

[0074] Optionally, calculating the light vector in the horizontal coordinate system according to the polarization angle and the polarization degree in the air includes:

[0075] S221, determining the e vector of the light coordinate system according to the polarization angle in the air;

[0076] S222, converting the e vector in the light coordinate system into the e vector in the horizontal coordinate system, and calculating the light vector in the horizontal coordinate system according to the e vector in the horizontal coordinate system and the degree of polarization.

[0077] Specifically, first, the e vector of the light coordinate system is represented by the polarization angle in the air, then the e vector of the light coordinate system is converted into the e vector in the horizontal coordinate system, and the light vector in the horizontal coordinate system is calculated based on the e vector and the polarization degree in the horizontal coordinate system by polarization weighting.

[0078] Optionally, converting the e-vector in the light coordinate system to the e-vector in the horizontal coordinate system includes:

[0079] S2221, determining the transformation relationship from the light coordinate system to the horizontal coordinate system;

[0080] S2222. Convert the e vector in the light coordinate system into the e vector in the horizontal coordinate system according to the conversion relationship.

[0081] The e vector in the l system is expressed as:

[0082] e l =[cosΦ a sinΦ a 0] T

[0083] The conversion relationship from the l system to the h system according to the incident angle i and the azimuth angle ξ is as follows:

[0084]

[0085] Then the e vector in the h system is:

[0086]

[0087] Finally, the polarization-weighted E is calculated in the Snell window. h Vector

[0088]

[0089] Where N is the number of valid pixels in the Snell window.

[0090] Optionally, the sun azimuth in the horizontal coordinate system is calculated based on the light vector, including:

[0091] S310, calculating the projection of the sun vector in the horizontal coordinate system according to the light vector;

[0092] S320, calculate the solar azimuth in the horizontal coordinate system according to the relationship between the zenith angle and the azimuth in the projection and the solar vector. Calculate the solar vector s h Projection formula in the horizontal coordinate system h:

[0093] s h =argmin((s h ) T E h (E h ) T s h ).st|s h |=1

[0094] Give the sun vector in h about the zenith angle and azimuth The projection relationship is as follows:

[0095]

[0096] Solving for the zenith angle and azimuth

[0097]

[0098]

[0099] Among them, s(3) represents the vector of the third position of the sun vector, s(2) represents the vector of the second position of the sun vector, and s(1) represents the vector of the first position of the sun vector.

[0100] The implementation of the embodiment of the present invention includes the following beneficial effects: in this embodiment, the polarization angle and polarization degree of underwater polarized light are first calculated according to the multi-channel least squares method to improve the calculation accuracy of polarized light, and then the light vector in the horizontal coordinate system is calculated according to the polarization angle and the polarization degree of the underwater polarized light, the light vector is converted to the horizontal coordinate system, and the solar azimuth in the horizontal coordinate system is calculated according to the light vector, and the heading angle is extracted according to the solar azimuth in the navigation coordinate system and the solar azimuth in the horizontal coordinate system. The calculation process is simple and the computing power is reduced, so that the heading angle information can be extracted in real time, efficiently and accurately.

[0101] The embodiment of the present invention is to h The construction method of is optimized to further improve the accuracy of heading angle calculation. Since the detection accuracy near the center of the camera field of view is high, that near the edge is low. In addition, the measurement points with polarization degrees lower than a certain critical value need to be eliminated to effectively prevent the influence of these points with poor measurement accuracy on the calculation accuracy. The selection of the optimal N value also needs to be analyzed according to the specific situation, and it is not always necessary to take the number of all valid pixels in the Snell window. h The weights, N, calculation step and other parameters are further optimized, and research is carried out on the efficient identification and elimination of samples with low measurement accuracy.

[0102] The optimal depth for calculating the heading angle and collecting PL light intensity data also needs to be analyzed. The asymptotic curve of the peak direction of underwater light intensity radiance is a key factor in determining the accuracy of heading angle calculation. Sky light is distributed within a 2π solid angle and is compressed within the Fresnel window angle (a conical window of about 97°) after refraction by the calm sea surface. For a calm sea surface in clear weather, when the descent depth is shallow, there is a sharp peak in the radiance distribution, and the peak direction is located in the direction of the sun's sea surface refraction light, which is caused by the dominant sun's sea surface refraction light. Due to the scattering effect of seawater, when the depth increases, the radiance peak gradually becomes gentle and moves toward the nadir. Finally, the asymptotic distribution that tends to be stable forms an asymptotic curve in which the radiance peak direction changes with depth; in fact, the sea surface is not calm, and the convergence and divergence of the light caused by the sea surface fluctuations causes the irradiance of the shallow seawater to change randomly; however, with the increase in depth, this effect gradually decreases. Therefore, at a shallow depth, the asymptotic curve of the underwater radiance peak direction fluctuates with time, and tends to be stable below 10m. The asymptotic curve of the peak direction of the ocean downward radiance contains the azimuth information of the sun and is affected by the optical properties of the seawater; therefore, when the AUV uses polarized light for attitude determination, the depth should be kept at around 10m.

[0103] The experiment of this study was carried out in two steps: the first step was to place a customized underwater camera equipped with a multi-layer metal polarization array into a pool, collect a large amount of data, and simulate the algorithm. The accuracy and reliability of the algorithm were verified by large-scale calculation samples, and the various parameters of the algorithm were optimized. The second step was to carry the camera on an AUV for an underwater actual flight test, and verify the accuracy, calculation speed and reliability of the algorithm on the AUV platform through actual flight. At the same time, all parameters in the algorithm can be further fine-tuned to improve accuracy.

[0104] See also Figure 4 , an embodiment of the present invention provides a heading angle extraction system, comprising:

[0105] The first module is used to calculate the polarization angle and polarization degree of underwater polarized light according to the multi-channel least square method;

[0106] The second module is used to calculate the light vector in the horizontal coordinate system according to the polarization angle and polarization degree of the underwater polarized light;

[0107] The third module is used to calculate the solar azimuth in the horizontal coordinate system according to the light vector, and extract the heading angle according to the solar azimuth in the navigation coordinate system and the solar azimuth in the horizontal coordinate system.

[0108] It can be seen that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0109] See also Figure 5 , an embodiment of the present invention provides a device for extracting a heading angle, comprising:

[0110] at least one processor;

[0111] at least one memory for storing at least one program;

[0112] When at least one program is executed by at least one processor, the at least one processor implements the above method.

[0113] Among them, the memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. The memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a remote memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0114] It can be seen that the contents of the above method embodiments are all applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0115] In addition, the embodiment of the present application also discloses a computer program product or a computer program, which is stored in a computer-readable storage medium. The processor of the computer device can read the computer program from the computer-readable storage medium, and the processor executes the computer program, so that the computer device performs the above method.

[0116] The embodiment of the present invention further provides a computer-readable storage medium, which stores a program executable by a processor, and the program executable by the processor is used to implement the above method when executed by the processor. Similarly, the contents of the above method embodiment are all applicable to the present storage medium embodiment, and the functions specifically implemented by the present storage medium embodiment are the same as those of the above method embodiment, and the beneficial effects achieved are also the same as those achieved by the above method embodiment.

[0117] It is understood that all or some steps and systems in the disclosed method above can be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, and the computer-readable medium can include a computer storage medium (or a non-transitory medium) and a communication medium (or a temporary medium). As known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassette, magnetic tape, disk storage or other magnetic storage device, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0118] The embodiment of the present invention provides a heading angle extraction system, comprising an underwater vehicle and a computer device connected to the underwater vehicle; wherein:

[0119] Underwater vehicles, for navigation of the sun's azimuth in the coordinate system;

[0120] Computer equipment includes:

[0121] at least one processor;

[0122] at least one memory for storing at least one program;

[0123] When at least one program is executed by at least one processor, the at least one processor implements the above method.

[0124] The underwater vehicle includes navigation equipment, power equipment, image acquisition equipment and optical measurement equipment, etc. The computer equipment includes but is not limited to laptop computers, desktop computers, terminals or wearable devices, etc.

[0125] It can be seen that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0126] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A method for extracting a heading angle, characterized in that: include: Calculate the polarization angle and polarization degree of underwater polarized light according to the multi-channel least squares method; Calculate the light vector in the horizontal coordinate system according to the polarization angle of the underwater polarized light and the polarization degree; The solar azimuth in the horizontal coordinate system is calculated according to the light vector, and the heading angle is extracted according to the solar azimuth in the navigation coordinate system and the solar azimuth in the horizontal coordinate system.

2. The method according to claim 1, characterized in that The method of calculating the polarization angle and polarization degree of underwater polarized light according to the multi-channel least squares method includes: Establish the corresponding relationship between the intensity of underwater polarized light and the polarization angle and polarization degree of underwater polarized light; A plurality of groups of underwater polarized light intensity measurement values ​​are obtained, and a least square method is used to calculate the polarization angle and polarization degree of the underwater polarized light according to the plurality of groups of the light intensity measurement values ​​and the corresponding relationship.

3. The method according to claim 1, characterized in that The step of calculating the light vector in the horizontal coordinate system according to the polarization angle and polarization degree of the underwater polarized light comprises: Determining the polarization angle in the air according to the polarization angle of the underwater polarized light; A light vector in a horizontal coordinate system is calculated according to the polarization angle in the air and the polarization degree.

4. The method according to claim 3, characterized in that The step of calculating the light vector in the horizontal coordinate system according to the polarization angle in the air and the polarization degree comprises: Determine the e-vector of the light coordinate system according to the polarization angle in the air; The e vector of the light coordinate system is converted into an e vector in a horizontal coordinate system, and the light vector in the horizontal coordinate system is calculated according to the e vector in the horizontal coordinate system and the polarization degree.

5. The method according to claim 4, characterized in that The step of converting the e-vector of the light coordinate system into the e-vector of the horizontal coordinate system comprises: Determine the transformation relationship from the light coordinate system to the horizontal coordinate system; The e-vector in the light coordinate system is converted into the e-vector in the horizontal coordinate system according to the conversion relationship.

6. The method according to claim 1, characterized in that The step of calculating the solar azimuth in the horizontal coordinate system according to the light vector comprises: Calculate the projection of the sun vector in the horizontal coordinate system according to the light vector; The solar azimuth in the horizontal coordinate system is calculated according to the relationship between the zenith angle and the azimuth in the projection and the solar vector.

7. A heading angle extraction system, characterized in that: include: The first module is used to calculate the polarization angle and polarization degree of underwater polarized light according to the multi-channel least square method; A second module is used to calculate the light vector in the horizontal coordinate system according to the polarization angle of the underwater polarized light and the polarization degree; The third module is used to calculate the solar azimuth in the horizontal coordinate system according to the light vector, and extract the heading angle according to the solar azimuth in the navigation coordinate system and the solar azimuth in the horizontal coordinate system.

8. A device for extracting a heading angle, characterized in that: include: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a program executable by a processor, characterized in that: The processor-executable program is used to perform the method according to any one of claims 1 to 6 when executed by the processor.

10. A heading angle extraction system, characterized in that: The invention comprises an underwater vehicle and a computer device connected to the underwater vehicle; wherein: The underwater vehicle is used to navigate the solar azimuth in the coordinate system; The computer device comprises: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method according to any one of claims 1 to 6.

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