CN114877898B - Sun dynamic tracking method based on underwater polarization attitude and refraction coupling inversion - Google Patents

Sun dynamic tracking method based on underwater polarization attitude and refraction coupling inversion Download PDF

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CN114877898B
CN114877898B CN202210808542.6A CN202210808542A CN114877898B CN 114877898 B CN114877898 B CN 114877898B CN 202210808542 A CN202210808542 A CN 202210808542A CN 114877898 B CN114877898 B CN 114877898B
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CN114877898A (en
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杨健
胡鹏伟
野召斌
郭雷
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Beihang University
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Abstract

The invention relates to a solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion. Firstly, an underwater polarization angle image is calculated by utilizing a polarized light intensity image acquired by an underwater polarization sensor, and an imaging pixel in a Snell window is determined by combining a horizontal attitude angle; then, calculating an underwater refraction angle of light rays entering the underwater polarization sensor by using the two horizontal attitude angles, converting an underwater polarization angle image in a Snell window into an atmospheric 8-shaped polarization angle image, further extracting a solar meridian from the atmospheric 8-shaped polarization angle image, and dividing the atmospheric 8-shaped polarization angle image into two areas by taking the atmospheric 8-shaped polarization angle image as a boundary; and finally, solving the sun vector by respectively utilizing the polarization E-vector and the polarization degree of the atmosphere solved by the pixels of the two areas. The invention considers the attitude dynamic change information of the carrier and expands the application scene of the sun tracking method based on polarized light in the underwater Snell window.

Description

Sun dynamic tracking method based on underwater polarization attitude and refraction coupling inversion
Technical Field
The invention belongs to the field of underwater autonomous navigation, and particularly relates to a solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion.
Background
The bionic polarized light navigation is a novel navigation means inspired by the behavior of determining the self course by sensing atmospheric polarized light by insects, has the advantages of complete autonomy, no error accumulation and the like, has been widely researched in the atmospheric environment at present, and the research of applying the polarized light navigation to underwater is still in the starting stage. The polarized light can provide navigation information because it contains sun information, so the basic idea of polarized light navigation is to solve the position of the sun through the obtained polarization information, and then realize navigation capability through the sun.
Solving the position of the sun based on polarized light is a premise of realizing navigation by utilizing the polarized light. The Chinese invention patent CN201410652332.8 utilizes the atmospheric polarization distribution mode to calculate the position of the sun by a cluster analysis method; the Chinese invention patent CN201710027484.2 uses the polarization E-vector of the atmosphere to establish the optimal estimation array of the sun vector to solve the sun position information; the invention patent CN201810592616.0 in china proposes a sun position calculating method based on atmospheric polarization degree. However, in an underwater environment, in the process of transmitting polarized light from the atmosphere into water, a refraction phenomenon occurs on the water surface, and the refraction changes the propagation direction of the polarized light and the deflection of a polarization plane, so that the above method for calculating the sun vector in the atmospheric environment is not suitable for the underwater environment; the chinese invention patent CN201911252040.4 proposes a sun tracking method based on polarized light in an underwater snell window, which compensates the effect of refraction on polarized light, but is only applicable to the application scene of a horizontal static base, and cannot be applied to the scene of attitude dynamic change. When dynamic change of the posture exists, the imaging position of the snell window in the image also changes, the image identification-based method is utilized, the Chinese patent invention CN202011307276.6 proposes a method for identifying the edge in the image to extract the snell window, but the image processing algorithm has large calculation amount and cannot be applied to real-time calculation of an underwater dynamic scene.
Different from the atmospheric environment, the sun tracking method based on the underwater polarized light field has obvious difference in two scenes of dynamic change of the carrier attitude in the underwater environment and a horizontal static base. The water surface refraction phenomenon occurs under a navigation coordinate system, and the information such as a refraction angle can be obtained only by calculating the horizontal posture for the compensation of the refraction action. Therefore, dynamic coupling of attitude and refraction phenomena exists in the underwater environment, which seriously affects the solar dynamic tracking precision based on the underwater polarized light field. Quantification and compensation of refraction in dynamic change of carrier attitude are key problems for improving applicability of dynamic application scenes of the sun tracking method.
Disclosure of Invention
In order to solve the technical problem, the invention provides a solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion, two horizontal attitude angles of a pitch angle and a roll angle are introduced to determine the imaging position of a Snell window and the refraction angle of light in the observation direction in the window, so that the influence of light bending and polarization plane deflection caused by refraction is compensated, and the solar dynamic tracking under the attitude/refraction coupling action is realized. Furthermore, the polarization degree reflects the quality of the polarized light, and the polarization degree is introduced to serve as the weight of each polarization E vector, so that the robustness of dynamic tracking of the sun can be improved. The invention combines the attitude information of the carrier, and inverts the refraction polarization light distribution mode in the underwater Snell window obtained under any attitude to obtain the polarization E-vector of the atmosphere by dynamic compensation of the refraction action on the water surface, thereby calculating the sun vector.
The technical scheme adopted by the invention for solving the technical problems is as follows: the solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion comprises the following implementation steps:
step (1) obtaining a polarized light intensity image by using an underwater polarization sensorP k （kFor analyzing the polarization direction) to calculate an underwater polarization angle image I, and combining the pitch angleθAnd roll angleγDetermining imaging pixels in a Snell window by the two horizontal attitude angles;
step (2) calculating the underwater refraction angle of the light entering the underwater polarization sensor by using the two horizontal attitude anglesrThe polarization angle image I in the underwater Snell window is processed by compensating refraction in Performing inversion calculation to obtain an atmospheric 8-shaped polarization angle image I in8 ；
Step (3), obtaining an atmospheric 8-shaped polarization angle image I in the step (2) in8 Extracting the solar meridian and dividing I by the solar meridian in8 Is divided into two partsRegion(s)p Ⅰ Andp Ⅱ ；
step (4), utilizing the atmospheric 8-shaped polarization angle image I obtained in the step (3) in8 Inp Ⅰ Andp Ⅱ and the pixels of the two regions solve the polarization E-vector and the polarization degree of the atmosphere, and solve the sun vector according to the orthogonal relation of the polarization E-vector and the sun vector of the atmosphere.
Further, the specific steps of step (1) are as follows:
defining a horizontal coordinate system (hSystem), carrier pitch angle and roll angle are respectivelyθAndγthen the carrier coordinate system (bSystem) andhthe coordinate transformation matrix between the systems is expressed as:
Figure 571961DEST_PATH_IMAGE001
coordinates of each pixel in underwater polarization angle image I (m,n) In thatbObservation vector under systeml b Inverted from the camera lens model Θ:
l b =Θ(m,n)
then the observation vector is inhIs represented as follows:
Figure 223522DEST_PATH_IMAGE002
if it ishUnder-system observation vectorl h Underwater angle of refraction of directionally incident light raysrIn an azimuth of
Figure 65576DEST_PATH_IMAGE003
Then, thenl h Can be expressed as:
Figure 195206DEST_PATH_IMAGE004
angle of refractionrIs acute angle, and has sine value of
Figure 743999DEST_PATH_IMAGE005
. Whereinl h Is represented byl h The first element of (a). Known from Snell's law of refraction, the angle of refraction underwaterrThe relationship between the angle of incidence of the light is:
Figure 628778DEST_PATH_IMAGE006
wherein the content of the first and second substances,n a andn w respectively representing the refractive indices in the atmosphere and in water,iis the angle of incidence of the light. When in usei<At 90 deg., the incident light can be refracted. The sine function is a monotone decreasing function in the acute angle range, so that the refraction angle in the Snell windowrThe requirements are satisfied:
Figure 630232DEST_PATH_IMAGE007
then, the underwater polarization angle image I is satisfied
Figure 829133DEST_PATH_IMAGE008
The pixel is judged to be in the Snell window, and the underwater Snell window polarization angle image I is obtained in 。
Further, the specific steps of the step (2) are as follows:
polarization angle image I in underwater snell window in The value of each pixel is the included angle between the atmospheric polarization E-vector and the image zero position in the observation direction of the pointαWherein, in the step (A),
Figure 29170DEST_PATH_IMAGE009
. The observation vector of the pixel obtained in the step (1) isl h Then, thenl h The azimuth angle of (A) is:
Figure 22534DEST_PATH_IMAGE010
the underwater "8" polarization azimuth angle χ of the pixel u Comprises the following steps:
Figure 776863DEST_PATH_IMAGE011
observation vectorl h Angle of refraction of directionally incident light rays under waterrComprises the following steps:
Figure 310612DEST_PATH_IMAGE012
the angle of incidence of the beam from the atmosphere can be calculated from snell's law of refraction:
Figure 568418DEST_PATH_IMAGE013
whereiniRepresenting the incident angle of the light, since the incident angle of the light is an acute angle, then:
Figure 795000DEST_PATH_IMAGE014
then the "8" polarization azimuth angle χ of the atmospheric incident ray a ：
Figure 505467DEST_PATH_IMAGE015
Wherein the content of the first and second substances,
Figure 46170DEST_PATH_IMAGE016
=tanχ u ；
and simultaneously calculating the propagation vector of the incident light of the atmosphere:
Figure 486379DEST_PATH_IMAGE017
the atmospheric incident light in the direction is directly imaged through a camera lens, and the imaging pixel coordinate (a)m a ,n a ) Comprises the following steps:
Figure 821545DEST_PATH_IMAGE018
wherein, the first and the second end of the pipe are connected with each other,round(. X) denotes rounding operation. Thereby obtainingm a ,n a ) Is a pixel coordinate of χ a Atmospheric "8" polarization angle image I as pixel values in8 。
Further, the specific steps in step (2) are as follows:
atmospheric 8-shaped polarization angle image I calculated in step (2) in8 The atmospheric polarization E-vector of the atmospheric incident polarized light corresponding to each pixel is:
Figure 284888DEST_PATH_IMAGE019
because the E-vector of the atmospheric polarization is perpendicular to the sun vector, the E-vector of the atmospheric polarization on the sun meridian is perpendicular to the sun meridian, and the 8-shaped polarization azimuth angle chi of the atmospheric incident light ray a And the polarization E-vector z-axis azimuth component of the atmosphere on the solar meridian is zero by substituting the formula. Therefore, a threshold value is set according to the actual situationκ,(κ>0) Is selected to satisfy
Figure 363702DEST_PATH_IMAGE020
Of a pixelp * As pixels near the solar meridian
Figure 658417DEST_PATH_IMAGE021
Whereine a (3) Representing a vectore a Third element of (2)(ii) a And fitting the pixels meeting the conditions to form a straight linem+An+B=0, whereinAAndBrespectively, the linear parameters are the atmospheric 8-shaped polarization angle image I in8 The solar meridian of (5).
When I in8 Inner pixel coordinate satisfiesm+An+B>At 0, the pixel is on one side of the solar meridian, and the set of all pixels in the area is defined asp Ⅰ (ii) a In the same way, when I in8 Inner pixel coordinate satisfiesm+An+B<At 0, the pixels are on the other side of the solar meridian, and the set of all pixels in the area is defined asp Ⅱ 。
Further, the specific steps of the step (4) are as follows:
obtaining polarized light intensity image by underwater polarization sensorPSolving out a polarization degree imageDAnd from I to I calculated in step (2) and step (3) in8 By a polarization degree imageDDetermination of I in8 The polarization degree corresponding to each pixel in the image is obtained to obtain an atmospheric polarization degree imageD in8 . The sum vector of the polarization E-vectors respectively constructing the two regional atmospheres is as follows:
Figure 164485DEST_PATH_IMAGE022
wherein the content of the first and second substances,E Ⅰ ，E Ⅱ respectively representing the sum vector of the polarization E-vectors of the two regional atmospheres,
Figure 115123DEST_PATH_IMAGE023
representing images of atmospheric polarization degreeD in8 The middle pixel coordinate is (m a ,n a ) The pixel value of (a), i.e., the degree of polarization;
Figure 997629DEST_PATH_IMAGE024
is represented by in8 The middle pixel coordinate is (m a ,n a ) Pixel value χ a And solving the calculated atmospheric polarization E-vector of the atmospheric incident polarized light.
Thus resolvinghSolar vector with ambiguity under systems h′ Comprises the following steps:
Figure 146850DEST_PATH_IMAGE025
taking into account that the sun is above the horizon during the day, the zenith vector is utilized
Figure 89399DEST_PATH_IMAGE026
To resolve the ambiguity, the final sun vector is as follows:
Figure 261754DEST_PATH_IMAGE027
whereinsign(v) represents the sign of v, from which the solution is derivedhIs the lower sun vector.
Has the beneficial effects that:
compared with the prior art, the invention has the following advantages: the existing sun tracking method based on underwater polarized light is only suitable for a horizontal static base scene. According to the solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion, the internal pixel of the Snell window in the polarization imaging is dynamically selected through the acquired horizontal attitude angle, the effect of refraction on atmospheric incident polarized light is dynamically compensated, and the polarization degree is introduced to be used as the atmospheric polarization E-vector weight, so that the accuracy and the robustness of solar dynamic tracking are improved.
Drawings
FIG. 1 is a flow chart of a solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion according to the present invention;
FIG. 2 is a schematic diagram of a coordinate system and refraction according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by a person skilled in the art based on the embodiments of the present invention belong to the protection scope of the present invention without creative efforts.
According to an embodiment of the present invention, as shown in fig. 1, the solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion of the present invention includes the following steps:
step 1, obtaining a polarized light intensity image by using an underwater polarization sensorP k Solving underwater polarization angle imagesIIn combination with carrier pitch angleθAnd roll angleγThe two horizontal attitude angles determine the imaging pixels within the snell window, wherekIs the polarization analysis direction. The method comprises the following specific steps:
in this embodiment, a four-channel underwater polarization sensor is taken as an example, and four-channel polarization analysis directions are respectively 0 °,45 °,90 ° and 135 °, so that the underwater polarization sensor acquires a polarized light intensity imageP 0 ,P 45 ,P 90 ,P 135 From this, the underwater polarization angle image I can be calculated as:
Figure 682371DEST_PATH_IMAGE028
defining a horizontal coordinate system (hSystem), carrier pitch angle and roll angle are respectivelyθAndγthen the carrier coordinate system (bSystem) andhthe coordinate transformation matrix between the systems is expressed as:
Figure 951678DEST_PATH_IMAGE001
coordinates of each pixel in underwater polarization angle image I (a)m,n) In thatbUnder-system observation vectorl b Inverted from the camera lens model Θ:
l b =Θ(m,n)
then the observation vector is inhIs represented as follows:
Figure 799549DEST_PATH_IMAGE002
if it ishObservation vector under systeml h The angle of refraction of a directionally incident ray under water isrIn an azimuth of
Figure 459200DEST_PATH_IMAGE003
Then, thenl h Can be expressed as:
Figure 683508DEST_PATH_IMAGE029
angle of refractionrIs acute angle, and has sine value of
Figure 807322DEST_PATH_IMAGE030
。
Angle of refraction known from Snell's law of refractionrAngle of incidence to lightiThe relationship between them is:
Figure 91673DEST_PATH_IMAGE031
wherein the content of the first and second substances,n a andn w respectively representing the refractive indices in the atmosphere and under water,iis the angle of incidence of the light.
When the temperature is higher than the set temperaturei<At 90 deg., the light is refracted. The sine function is a monotone decreasing function in the acute angle range, so the refraction angle in the Snell windowrThe requirements are satisfied:
Figure 566516DEST_PATH_IMAGE032
then, it is satisfied in the underwater polarization angle image I
Figure 606234DEST_PATH_IMAGE033
The pixel is judged to be in the Snell window, and a polarization angle image I in the underwater Snell window is obtained in . Whereinl h Is represented byl h The first element of (a).
Step 2, calculating the refraction angle of the light entering the underwater polarization sensor by using the two horizontal attitude anglesrThe polarization angle image I in the underwater Snell window is obtained by compensating refraction in Performing inversion calculation to obtain an atmospheric 8-shaped polarization angle image I in8 . The method comprises the following specific steps:
polarization angle image I in underwater snell window in The value of each pixel is the included angle between the polarized light vibration direction and the image zero position in the observation direction of the pointαWherein, in the step (A),αin the range of
Figure 584554DEST_PATH_IMAGE009
。
The observation vector of the pixel obtained from step 1 isl h Then, thenl h The azimuth angle of (c) is:
Figure 39806DEST_PATH_IMAGE034
the underwater 8-shaped polarization azimuth angle of the pixelχ u Comprises the following steps:
Figure 674050DEST_PATH_IMAGE035
observation vectorl h Angle of refraction of directionally incident light rays under waterrComprises the following steps:
Figure 36898DEST_PATH_IMAGE036
the beam of light is from the atmosphereAngle of incidenceiCan be calculated from snell's law of refraction:
Figure 807408DEST_PATH_IMAGE037
whereiniRepresenting the angle of incidence of the light. Since the incident angle of the light is acute, then:
Figure 230299DEST_PATH_IMAGE038
as shown in FIG. 2, the E-vector of polarization of the atmosphere can be decomposed into two orthogonal components, each perpendicular to the plane of refractione ⊥ And parallel to the refracting surfacese ‖ . When the water surface refraction occurs, the attenuation degrees of the two components are different, the polarized light enters underwater after being refracted by air, and the two components are expressed ast ⊥ Andt ‖ obtained by the Fresnel refraction formula:
Figure 617418DEST_PATH_IMAGE039
the following relation exists between the atmospheric and underwater 8-shaped polarization azimuth angles before and after refraction:
Figure 456061DEST_PATH_IMAGE040
then the "8" polarization azimuth angle χ of the atmospheric incident ray a Can be expressed as:
Figure 408974DEST_PATH_IMAGE041
wherein, the first and the second end of the pipe are connected with each other,
Figure 940449DEST_PATH_IMAGE016
=tanχ u ；
observation vectorl h In an azimuth of
Figure 549285DEST_PATH_IMAGE003
The zenith angle is equal to the refraction anglerThen, thenl h Can be expressed as:
Figure 519515DEST_PATH_IMAGE029
the azimuth angle of the atmospheric incident light before and after refraction is unchanged, and only the zenith angle is changed. The zenith angle of the atmospheric incident light is the incident angle of the lightiThen, as shown in FIG. 2, the propagation vector of the incident light of the atmospherel a In thathIs represented by
Figure 530196DEST_PATH_IMAGE042
Due to the fact that
Figure 232573DEST_PATH_IMAGE043
Therefore:
Figure 125443DEST_PATH_IMAGE044
imaging the directional atmospheric incident light directly through the camera lens, imaging pixel coordinates: (m a ,n a ) Comprises the following steps:
Figure 571468DEST_PATH_IMAGE045
whereinround(. Indicates rounding to the integer operation. Thereby obtainingm a ,n a ) Is a pixel coordinate of χ a Atmospheric "8" polarization angle image I of pixel values in8 。
Step 3, obtaining an atmospheric 8-shaped polarization angle image I in the step 2 in8 Extracting the solar meridian, and dividing I by the solar meridian in8 Divided into two regionsp Ⅰ Andp Ⅱ . The method comprises the following specific steps:
atmospheric 8-shaped polarization angle image I calculated in step 2 in8 Each pixel value is the atmospheric polarization E-vector of the atmospheric incident polarized light corresponding to the pixele a In thathIs represented as follows:
e a =v cosχ a +u sinχ a
whereinv,uRespectively represents the tangential unit vector of the meridian direction and the latitude direction of the celestial sphere observation point in the atmosphere, and the tangential unit vector is as follows:
Figure 436655DEST_PATH_IMAGE046
this gives:
Figure 372250DEST_PATH_IMAGE047
because the E-vector of the atmospheric polarization is perpendicular to the sun vector, the E-vector of the atmospheric polarization on the sun meridian is perpendicular to the sun meridian, and the azimuth angle of the 8-shaped polarization of the incident light of the atmospheric polarizationχ a =90 °, substituting the above equation yields zero z-axis azimuthal component of the polarization E-vector of the atmosphere located on the solar meridian. Therefore, a threshold value is set according to the actual situationκ,(κ>0) Is selected to satisfy
Figure 690099DEST_PATH_IMAGE020
Is formed by a plurality of pixelsp * As pixels near the solar meridian
Figure 939815DEST_PATH_IMAGE021
In whiche a (3) Representing a vectore a The third element of (1); and fitting the pixels meeting the condition to form a straight linem+An+B=0, whereinAAnd withBRespectively, the linear parameters are the atmospheric 8-shaped polarization angle image I in8 The middle solar meridian.
When I is in8 Inner pixel coordinate satisfiesm+An+B>At 0, the pixel is on one side of the solar meridian, and the set of all pixels in the area is defined asp Ⅰ (ii) a In the same way, when I in8 Inner pixel coordinate satisfiesm+An+B<At 0, the pixels are on the other side of the solar meridian, and the set of all pixels in the area is defined asp Ⅱ 。
Step 4, utilizing the atmospheric 8-shaped polarization angle image I obtained in the step 3 in8 In (1)p Ⅰ Andp Ⅱ and (3) calculating the polarization E-vector and the polarization degree of the atmosphere by using the pixels of the two areas, and calculating the sun vector according to the vertical relation of the polarization E-vector and the sun vector of the atmosphere. The method comprises the following specific steps:
obtaining polarized light intensity images by an underwater polarization sensorP k Solving out images of degree of polarizationD：
Figure 721826DEST_PATH_IMAGE048
From I to I calculated in step 2 and step 3 in8 Using a polarization degree imageDDetermination of I in8 Obtaining an atmospheric polarization degree image by the corresponding polarization degree of each pixelD in8 . Then order:
Figure 766006DEST_PATH_IMAGE049
wherein the content of the first and second substances,E Ⅰ ，E Ⅱ respectively representing the sum vector of the polarization E-vectors of the two regional atmospheres,
Figure 836730DEST_PATH_IMAGE050
representing images of atmospheric polarization degreeD in8 The middle pixel coordinate is (m a ,n a ) The pixel value of (a), i.e., the degree of polarization;
Figure 686874DEST_PATH_IMAGE051
by the expression I in8 The middle pixel coordinate is (m a ,n a ) Pixel value χ a And solving the atmospheric polarization E-vector of the atmospheric incident polarized light.
Thus resolvinghSystematic ambiguity sun vectors h′ Comprises the following steps:
Figure 261075DEST_PATH_IMAGE052
the zenith vector is utilized in view of the fact that the sun is generally above the horizon during the day
Figure 741735DEST_PATH_IMAGE053
To resolve the ambiguity, the final sun vector is as follows:
Figure 830914DEST_PATH_IMAGE054
whereinsign(v) represents the sign of v, from which the calculation is madehIs the lower sun vector.
Although illustrative embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the embodiments, but various changes may be apparent to those skilled in the art, and it is intended that all inventive concepts utilizing the inventive concepts set forth herein be protected without departing from the spirit and scope of the present invention as defined and limited by the appended claims.

Claims (5)

1. A solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion is characterized by comprising the following steps:
step (1) obtaining a polarized light intensity image by using an underwater polarization sensorP k Calculating an underwater polarization angle image I and combining a carrier pitch angleθAnd roll angleγDetermining imaging pixels in a Snell window by two horizontal attitude angles to obtain a polarization angle image I in the underwater Snell window in WhereinkIs the direction of polarization analysis; in particular, according to carrier pitch angleθAnd roll angleγThe coordinates of each pixel in the underwater polarization angle image I are calculated (m,n) Observation vector under carrier coordinate systeml b Conversion to horizontal coordinate system to obtainl h Satisfaction in the underwater polarization angle image I
Figure 71013DEST_PATH_IMAGE001
The pixel is judged to be in the Snell window, and the polarization angle image I in the underwater Snell window is obtained in (ii) a Whereinl h Is expressed asl h The first element of (a) is,n a andn w respectively, the refractive indices at atmosphere and water;
step (2) calculating the underwater refraction angle of the light entering the underwater polarization sensor by using the two horizontal attitude anglesrThe polarization angle image I in the underwater Snell window is obtained by compensating refraction in Performing inversion calculation to obtain an atmospheric 8-shaped polarization angle image I in8 ；
Step (3), obtaining an atmospheric 8-shaped polarization angle image I in the step (2) in8 Extracting the solar meridian, and dividing I by the solar meridian in8 Divided into two regionsp Ⅰ Andp Ⅱ ；
step (4) of utilizing the atmospheric 8-shaped polarization angle image I obtained in the step (3) in8 Inp Ⅰ Andp Ⅱ and (3) calculating the polarization E-vector and the polarization degree of the atmosphere by using the pixels of the two areas, and calculating the sun vector according to the vertical relation of the polarization E-vector and the sun vector of the atmosphere.
2. The solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion of claim 1, characterized in that:
the specific steps of the step (1) are as follows:
defining a horizontal coordinate system, and the pitch angle and the roll angle of the carrier are respectivelyθAndγthen, the coordinate transformation matrix between the carrier coordinate system and the horizontal coordinate system is expressed as:
Figure 387725DEST_PATH_IMAGE002
wherein the horizontal coordinate system ishSystem, carrier coordinate systembIs to be prepared;
coordinates of each pixel in underwater polarization angle image I (a)m,n) In thatbObservation vector under systeml b Inverted from the camera lens model Θ:
l b =Θ(m,n)
then the observation vector is inhIs represented as follows:
Figure 578535DEST_PATH_IMAGE003
satisfaction in underwater polarization angle image I
Figure 6105DEST_PATH_IMAGE001
The pixel is judged to be in the Snell window, and the polarization angle image I in the underwater Snell window is obtained in (ii) a Whereinl h Is represented byl h The first element of (a) is,n a andn w respectively, the refractive indices in the atmosphere and water.
3. The solar dynamic tracking method based on underwater polarization attitude and refraction coupling inversion of claim 2, characterized in that:
the specific steps of the step (2) are as follows:
polarization angle image I in underwater snell window in The value of each pixel is the included angle between the atmospheric polarization E-vector and the image zero position in the observation direction of the corresponding pixel pointαWherein, in the process,αin the range of
Figure 333182DEST_PATH_IMAGE004
；
The observation vector of the imaging pixel obtained in the step (1) isl h The underwater "8" polarization azimuth angle χ of the imaging pixel u Comprises the following steps:
Figure 820795DEST_PATH_IMAGE005
；
wherein
Figure 498901DEST_PATH_IMAGE006
，
Figure 730162DEST_PATH_IMAGE007
Is 1 of h The azimuth of (d);
observation vectorl h Angle of refraction of directionally incident light rays under waterrComprises the following steps:
Figure 177324DEST_PATH_IMAGE008
then the "8" polarization azimuth angle χ of the atmospheric incident ray a Comprises the following steps:
Figure 570259DEST_PATH_IMAGE009
wherein, the first and the second end of the pipe are connected with each other,
Figure 735661DEST_PATH_IMAGE010
=tanχ u ；
and simultaneously calculating the propagation vector of the incident light of the atmosphere:
Figure 505034DEST_PATH_IMAGE011
imaging the directional atmospheric incident light directly through the camera lens, imaging pixel coordinates: (m a ,n a ) Comprises the following steps:
Figure 72282DEST_PATH_IMAGE012
whereinround(x) denotes rounding;
thereby obtaining (A) am a ,n a ) Is a pixel coordinate of χ a Atmospheric "8" polarization angle image I of pixel values in8 。
4. The method of claim 3 for solar dynamic tracking based on underwater polarization attitude and refraction coupling inversion, characterized in that:
the specific steps of the step (3) are as follows:
atmospheric 8-shaped polarization angle image I calculated in step (2) in8 The atmospheric polarization E-vector of the atmospheric incident polarized light corresponding to each pixel is:
Figure 636118DEST_PATH_IMAGE013
wherein the content of the first and second substances,irepresents the angle of incidence of the light; because the E-vector of the atmospheric polarization is perpendicular to the sun vector, the E-vector of the atmospheric polarization on the sun meridian is perpendicular to the sun meridian, and the '8' -shaped polarization azimuth angle chi of the atmospheric incident light ray a =90 °, generationThe polarization E-vector z-axis azimuth component of the atmosphere on the solar meridian is zero by entering the formula; therefore, a threshold value is setκ，κ>0, is selected to satisfy
Figure 288816DEST_PATH_IMAGE014
Of a pixelp * As pixels near the solar meridian
Figure 861880DEST_PATH_IMAGE015
In whiche a (3) Representing a vectore a The third element of (1); and fitting the pixels meeting the conditions to form a straight linem+An+B=0, whereinAAndBrespectively the parameters of the straight line, the straight line is the atmospheric 8-shaped polarization angle image I in8 The solar meridian of (1);
when I in8 Inner pixel coordinate satisfiesm+An+B>At 0, the pixel is on one side of the solar meridian, and the set of all pixels in the area is defined asp Ⅰ (ii) a When I is in8 Inner pixel coordinate satisfiesm+An+B<At 0, the pixels are on the other side of the solar meridian, and the set of all pixels in the area is defined asp Ⅱ 。
5. The underwater polarization attitude and refractive coupling inversion based dynamic sun tracking method according to claim 4, characterized in that:
the specific steps of the step (4) are as follows:
obtaining polarized light intensity images by an underwater polarization sensorP k Solving out a polarization degree imageDAnd from I to I calculated in the step (2) and the step (3) in8 By a polarization degree imageDDetermination of I in8 The corresponding polarization degree of each pixel in the image is obtained to obtain an atmospheric polarization degree imageD in8 (ii) a The sum vector of the polarization E-vectors respectively constructing the two regional atmospheres is as follows:
Figure 18055DEST_PATH_IMAGE016
wherein the content of the first and second substances,E Ⅰ ，E Ⅱ respectively representing the sum vector of the polarization E-vectors of the two regional atmospheres,
Figure 18372DEST_PATH_IMAGE017
representing images of atmospheric polarization degreeD in8 The middle pixel coordinate is (m a ,n a ) The pixel value of (a), i.e., the degree of polarization;
Figure 892787DEST_PATH_IMAGE018
is represented by I in8 Middle pixel coordinate (C:)m a ,n a ) Pixel value χ a Solving the calculated atmospheric polarization E-vector of the atmospheric incident polarized light;
solution tohSystematic ambiguity sun vectors h′ Comprises the following steps:
Figure 66279DEST_PATH_IMAGE019
because the sun is above the horizon in the daytime, the zenith vector is utilized
Figure 280223DEST_PATH_IMAGE020
Disambiguation, the final sun vector is as follows:
Figure 513758DEST_PATH_IMAGE021
whereinsign(v) represents the sign of v, from which the solution is derivedhIs the lower sun vector.
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CN116222580B (en) * 2023-05-09 2023-07-25 北京航空航天大学 Underwater polarization orientation method based on cross-medium refraction interference compensation correction
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105181145A (en) * 2015-11-13 2015-12-23 北京航空航天大学 Method for simulating underwater polarization field of wave water surface transmitted light
CN111027231A (en) * 2019-12-29 2020-04-17 杭州科洛码光电科技有限公司 Underwater array camera imaging method
CN111220150A (en) * 2019-12-09 2020-06-02 北京航空航天大学 Sun vector calculation method based on underwater polarization distribution mode
CN111854957A (en) * 2020-07-21 2020-10-30 北京航空航天大学 Underwater polarization autonomous orientation method based on underwater light intensity interference model
CN112419410A (en) * 2020-11-20 2021-02-26 北京航空航天大学 Horizontal attitude determination method based on underwater Snell window edge identification
CN112461191A (en) * 2020-11-20 2021-03-09 北京航空航天大学 Sun height calculating method based on underwater refraction and scattering coupling polarization degree
WO2022022975A1 (en) * 2020-07-30 2022-02-03 Orphie Method and device for underwater imaging

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7630077B2 (en) * 2006-10-13 2009-12-08 University Of Massachusetts System and method for imaging through an irregular water surface

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105181145A (en) * 2015-11-13 2015-12-23 北京航空航天大学 Method for simulating underwater polarization field of wave water surface transmitted light
CN111220150A (en) * 2019-12-09 2020-06-02 北京航空航天大学 Sun vector calculation method based on underwater polarization distribution mode
CN111027231A (en) * 2019-12-29 2020-04-17 杭州科洛码光电科技有限公司 Underwater array camera imaging method
CN111854957A (en) * 2020-07-21 2020-10-30 北京航空航天大学 Underwater polarization autonomous orientation method based on underwater light intensity interference model
WO2022022975A1 (en) * 2020-07-30 2022-02-03 Orphie Method and device for underwater imaging
CN112419410A (en) * 2020-11-20 2021-02-26 北京航空航天大学 Horizontal attitude determination method based on underwater Snell window edge identification
CN112461191A (en) * 2020-11-20 2021-03-09 北京航空航天大学 Sun height calculating method based on underwater refraction and scattering coupling polarization degree

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
"Solar-tracking methodology based on refraction-polarization in Snell’s window for underwater navigation";Pengwei HU 等，;《Chinese Journal of Aeronautics》;20210320;第35卷(第3期);380-389页 *
"Underwater polarization patterns considering single Rayleigh scattering of water molecules";Haoyuan Cheng 等，;《INTERNATIONAL JOURNAL OF REMOTE SENSING》;20191029;1-16页 *
"天空光主导的波浪水面下偏振分布模型仿真";褚金奎 等，;《光学学报》;20201031;第40卷(第20期);1-8页 *
"水下对空成像中的波面估计";叶春明，;《光学与光电技术》;20110430;第9卷(第2期);33-36页 *

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