Polarization database acquisition device and method for red tide based on polarization two-way reflection model

Abstract

The application discloses a red tide polarization database acquisition device and method based on a polarization bidirectional reflection model, belongs to the technical field of data acquisition devices, selects a polarization bidirectional reflection model to perform modeling, and performs data acquisition on related data such as different solar zenith angles, different solar azimuth angles, different observation zenith angles, different observation azimuth angles, different wind speeds, different wind directions, different seawater temperatures and different seawater salinities in different regions of the sea through the red tide polarization database acquisition device. In actual testing, the theoretical formula derivation is compared with the actual acquisition result, if the confidence degree is more than 60%, the model is confirmed to be accurate, otherwise, the model is optimized, secondary modeling is performed to increase the fitting degree of the model, and the purpose of accurately identifying red tide dominant species is achieved, and the prediction accuracy of red tide is improved. The application solves the problems that the existing polarization database lacks data of red tide dominant species, a large amount of manpower and material resources are required to detect and analyze collected red tide water sample, and the efficiency is low and the cost is high.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of data acquisition devices, and particularly relates to a red tide polarization database acquisition device and method based on a polarization bidirectional reflection model. BACKGROUND

[0002] In recent years, red tide disasters occur frequently, which has a great impact on fishery resources and the survival of marine organisms, and also causes certain economic losses to the tourism industry along the way. The formation mechanism of red tide is very complex, and in recent years, many researchers have conducted in-depth research on it. The commonly used water quality detection and buoy station continuous automatic monitoring method consumes manpower and material resources, and is prone to false detection and missed detection due to the presence of other pollutants in the ocean, and the accuracy of predicting red tide is not ideal. The ship-borne optical instrument measurement method needs to be sampled at a fixed point, and due to the need for chemical analysis and manual processing, the efficiency is not high and the cost is high. In view of the characteristics of many types of red tide, the conventional optical method cannot quickly analyze the dominant species of red tide, and since the polarization light has different scattering characteristics when it is transmitted in different types of microorganisms and cells, the types of microorganisms and cells can be accurately analyzed, so the polarization technology is widely used in camouflage target recognition, cancer cell detection, steel flaw detection and other occasions. At present, in order to improve the accuracy of predicting red tide, a red tide polarization database needs to be established, but the establishment of the red tide polarization database is slow.

[0003] Therefore, there is an urgent need in the prior art for a new device and method to establish a red tide polarization database. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a red tide polarization database acquisition device and method based on a polarization bidirectional reflection model, which selects a polarization bidirectional reflection model for modeling, and collects data on different solar zenith angles, different solar azimuth angles, different observation zenith angles, different observation azimuth angles, different wind speeds, different wind directions, different seawater temperatures, different seawater salinities and other related data in different regions of the ocean through the red tide polarization database acquisition device. In actual testing, the theoretical formula derivation is compared with the actual collection results, and if the confidence level exceeds 60%, it is confirmed that the model is accurate, otherwise the model is optimized for secondary modeling to increase the adaptability of the model, so as to accurately identify the dominant species of red tide and improve the accuracy of predicting red tide. The problem of lack of data on dominant species of red tide in the existing polarization database is solved, and a large amount of manpower and material resources are needed to detect and analyze the collected red tide water samples whenever red tide occurs, which is low in efficiency and high in cost.

[0005] The application discloses a red tide polarization database collection device based on a polarization bidirectional reflection model, which comprises a polarization imaging system and a polarization database collection system.

[0006] The polarization database collection system outputs, stores and processes the polarization images collected by the polarization imaging system.

[0007] The polarization database collection system further comprises a turntable control unit, a GPS positioning unit and a turntable.

[0008] The polarization database collection system further comprises a power supply unit for supplying power to the center control unit, the image output unit, the image storage and processing unit, the turntable control unit, the GPS positioning unit and the turntable.

[0009] The center control unit controls the polarization directions of the polarization modulation unit I, the polarization modulation unit II and the polarization modulation unit III.

[0010] The application further discloses a red tide polarization database collection method based on the polarization bidirectional reflection model.

[0011] When red tide occurs, the wind speed, the wind direction, the seawater temperature and the seawater salinity are monitored by an ecological environment monitoring station, the red tide area is divided into different regions according to different wind speeds, wind directions, seawater temperatures and seawater salinities, and the unmanned aerial vehicle is used to carry the red tide polarization database collection device based on the polarization bidirectional reflection model to collect images of the regions.

[0012] Step two, the real-time position information is confirmed by using the GPS positioning unit, and the real-time solar zenith angle and azimuth angle are recorded, the turntable is controlled by the central control unit to control the turntable control unit to rotate, the observation azimuth angle of the turntable is adjusted to 90°, and the observation zenith angle at this time is set to 10°; the polarization direction is adjusted to 0°, 45°, 90° and 135° in turn by the central control unit controlling the polarization modulation unit I, the polarization modulation unit II and the polarization modulation unit III, the image acquisition is carried out by using the visible light camera, the short-wave infrared camera and the long-wave infrared camera in the polarization imaging system, the central control unit transmits the polarization image to the image output unit, and the image output unit transmits the polarization image to the image storage and processing unit for image storage and processing;

[0013] Step three, the central control unit controls the turntable control unit to rotate the turntable, adjusts the observation azimuth angle of the turntable to 180°, and sets the observation zenith angle at this time to 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80° and 90° respectively, and repeats the operation of step two to store and process the images;

[0014] The observation azimuth angle of the turntable is adjusted to 270°, and the observation zenith angle at this time is set to 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80° and 90° respectively, and the operation of step two is repeated to store and process the images;

[0015] Step four, the solar zenith angle is monitored every 10° by using the ecological environment monitoring station, the red tide polarization database acquisition device based on the polarization bidirectional reflection model is used to fly again, the same area is reached, steps two and three are repeated respectively, and the image obtained is stored and classified according to the solar zenith angle, the solar azimuth angle, the observation zenith angle, the observation azimuth angle, the wind speed, the wind direction, the sea water temperature and the sea water salinity to edit the red tide polarization database;

[0016] Step five, the data of the polarization image in the red tide polarization library is matched by using the model to establish the polarization bidirectional reflection distribution function:

[0017]

[0018] In the formula, θ s is the solar zenith angle; is the solar azimuth angle; θ v is the observation zenith angle; is the observation azimuth angle; dE is the incident irradiance; dL rp is the polarization reflection irradiance;

[0019] The sea surface wind speed and the probability distribution function of the two-dimensional rough sea surface are:

[0020]

[0021] In the formula, S up S is the slope of the small inclined plane against the wind; cross σ represents the slope of the small-scale crosswind; up σ represents the RMS value of the headwind on a small inclined plane; cross RMS value for a small, tilted plane crosswind;

[0022] The relationship between seawater roughness and wind speed v is as follows:

[0023]

[0024] The slope S of the sea surface tilted microplane element on the reference axes of azimuth and zenith angle. x S y The relationship with the zenith angle and azimuth angle is as follows:

[0025]

[0026]

[0027] The tilt angle β and direction slope S of the sea surface tilted microplane element x S y The relationship is:

[0028]

[0029] The slopes of the headwind and crosswind directions are related to S. x S y The relationship is:

[0030]

[0031] In the formula, The azimuth angle for the sea breeze direction;

[0032] Sunlight, after being reflected by red algae, exhibits polarization characteristics. Using Fresnel's reflection equation, polarized light can be decomposed into s-polarization and p-polarization components, with the following relationship:

[0033]

[0034]

[0035] In the formula, r s r is the reflection coefficient of the s-polarization component; p n is the reflection coefficient of the p-polarized component; n1 is the refractive index of air; n2 is the refractive index of red tide; θ i θ is the angle of incidence of the sun. t The angle of refraction;

[0036] Where the air refractive index formula is:

[0037]

[0038] The seawater refractive index formula is:

[0039]

[0040] Where p is air pressure; T is temperature; and λ is wavelength;

[0041] By combining the above formulas, the relationship between the polarization reflectance and the degree of polarization is ultimately obtained as:

[0042]

[0043]

[0044] Where R p,rt (θ s ,θ v ,φ v ,φ wind ,n rt ,v) is the polarization reflectance of the red tide p-polarization component; R S,rt (θ s ,θ v ,φ v ,φ wind ,n rt ,v) is the polarization reflectance of the red tide s-polarization component; r p,rt is the reflectance of the red tide p-polarization component; r s,rt is the reflectance of the red tide s-polarization component; and p is the degree of polarization.

[0045] The measured data collected on the same day in the steps one to four are taken as the simulation parameters and are brought into the formulas to solve the polarization reflectance and the degree of polarization, and are matched with the measured data; the confidence is used for verification, and the confidence formula is:

[0046]

[0047] In the formula, M is the confidence, R s and R a respectively represent the simulation value and the known value of the red tide polarization database.

[0048] If the confidence is higher than 60%, the model is accurate, and if the confidence is lower than 60%, the model is inaccurate; secondary modeling is performed to increase the authenticity of the model, the measured data are linearly fitted, the relationship between the independent variable and the dependent variable is established by using a linear regression model, and the linear regression model formula is:

[0049]

[0050] where Y p is the dependent variable; X p1 , X p2 , X p3 , X p4 , X p5 , X p6 as the independent variable simulation and the main interference conditions in the measured data; is the independent variable simulation and the main interference weight in the measured data; the greater the weight proves that a certain interference condition has greater influence on the final simulation data, and vice versa; the model after the secondary modeling is verified by the confidence degree, and the model is accurate when the confidence degree is higher than 60%.

[0051] Through the above design scheme, the red tide polarization database acquisition device and method based on the polarization bidirectional reflection model can bring the following beneficial effects: the red tide polarization database and the simulation model are combined, the polarization image collected is used to form the red tide polarization database, the simulation is performed by introducing related parameters by using the simulation model, the confidence degree is used as the standard for judging the model accuracy, if the confidence degree is low, secondary modeling is adopted, linear fitting is performed on the obtained measured data, a linear regression model is obtained, the model with higher confidence degree is obtained by verifying the confidence degree, and the model algorithm is more and more accurate, so that the model with higher confidence degree can be obtained, the red tide polarization database established by the present application can provide effective reference for subsequent model establishment, and has important significance for improving the accuracy of red tide prediction. BRIEF DESCRIPTION OF DRAWINGS

[0052] The present application is further described below in combination with the drawings and specific embodiments:

[0053] Figure 1 Fig. 1 is a structural schematic view of the red tide polarization database acquisition device based on the polarization bidirectional reflection model of the present application.

[0054] In the figure, 1 is a polarization imaging system, 2 is a polarization database acquisition system, 11 is a light splitting prism I, 12 is a polarization modulation unit I, 13 is a visible light camera, 14 is a light splitting prism II, 15 is a polarization modulation unit II, 16 is a short-wave infrared camera, 17 is a reflector, 18 is a polarization modulation unit III, 19 is a long-wave infrared camera, 21 is a central control unit, 22 is a power unit, 23 is an image output unit, 24 is an image storage and processing unit, 25 is a turntable control unit, 26 is a GPS positioning unit, and 27 is a turntable. DETAILED DESCRIPTION

[0055] The red tide polarization database acquisition device based on the polarization bidirectional reflection model comprises a polarization imaging system, a polarization database acquisition system, a central control unit, a power unit, an image output unit, an image storage and processing unit, a turntable control unit, a GPS positioning unit, and a turntable. Figure 1As shown, it comprises a polarization imaging system 1 and a polarization database acquisition system 2, the polarization imaging system 1 is used for acquiring polarization images in visible light, short-wave infrared and long-wave infrared bands, the polarization database acquisition system 2 is used for image output, storage and processing of the acquired polarization images in the three bands, and real-time position information is transmitted to a turntable control unit 25 through a GPS positioning unit 26, and the turntable 27 is controlled to track through the turntable control unit 25, and complete polarization database acquisition is carried out.

[0056] The polarization imaging system 1 comprises a light splitting prism I 11, a polarization modulation unit I 12, a visible light camera 13, a light splitting prism II 14, a polarization modulation unit II 15, a short-wave infrared camera 16, a mirror 17, a polarization modulation unit III 18 and a long-wave infrared camera 19, wherein incident light is transmitted to the visible light camera 13, the short-wave infrared camera 16 and the long-wave infrared camera 19 through the light splitting prism I 11, the light splitting prism II 14 and the mirror 17, and the polarization modulation unit I 12, the polarization modulation unit II 15 and the polarization modulation unit III 18 are controlled by a central control unit 21 to adjust to different polarization directions to obtain polarization incident light with the same direction as the transmission axis direction, and the received light signals are output as polarization images by the visible light camera 13, the short-wave infrared camera 16 and the long-wave infrared camera 19.

[0057] The polarization database acquisition system 2 comprises the central control unit 21, a power supply unit 22, an image output unit 23, an image storage and processing unit 24, the turntable control unit 25, the GPS positioning unit 26 and the turntable 27, wherein the central control unit 21 is connected to the visible light camera 13, the short-wave infrared camera 16 and the long-wave infrared camera 19, transmits the polarization images to the image output unit 23, and then transmits the polarization images to the image storage and processing unit 24 for image storage and processing through the image output unit 23, the GPS positioning unit 26 feeds back real-time position information to the turntable control unit 25, the turntable control unit 25 is controlled by the central control unit 21 to track and rotate the turntable 27, and the power supply unit 22 supplies power to the central control unit 21, the image output unit 23, the image storage and processing unit 24, the turntable control unit 25, the GPS positioning unit 26 and the turntable 27.

[0058] In this embodiment, the polarization directions in the polarization modulation unit I 12, the polarization modulation unit II 15 and the polarization modulation unit III 18 can be adjusted to any direction from 0 to 360 degrees.

[0059] In this embodiment, the wavelength range of the visible light camera 13 is 0.4-0.75 μm, the wavelength range of the short-wave infrared camera 16 is 1-1.7 μm, and the wavelength range of the long-wave infrared camera 19 is 8-12 μm.

[0060] In the embodiment, the central control unit 21 is responsible for controlling the polarization directions of the polarization modulation unit I 12, the polarization modulation unit II 15 and the polarization modulation unit III 18, and is connected with the image output unit 23 and the turntable control unit 25 to control the output of the image and the control of the turntable 27.

[0061] In the embodiment, the image output unit 23 transmits the image to the image storage and processing unit 24 to complete the output, storage and processing of the image.

[0062] In the embodiment, the GPS positioning unit 26 transmits the real-time position information to the turntable control unit 25, and the turntable control unit 25 is controlled by the central control unit 21 to track and rotate the turntable 27.

[0063] The application also provides a red tide polarization database collection method based on a polarization bidirectional reflection model, and the specific steps are as follows:

[0064] Step 1: When red tide occurs, contact the local ecological environment monitoring station to retrieve the wind speed, wind direction, seawater temperature and seawater salinity of the day, divide the red tide area into different wind speed, wind direction, seawater temperature and seawater salinity areas, and use a UAV to carry the device to collect images in different areas.

[0065] Step 2: Use the GPS positioning unit 26 to confirm whether the real-time position information reaches the specified area, record the real-time solar zenith angle and azimuth angle, rotate the turntable 27 by the turntable control unit 25 controlled by the central control unit 21, adjust the observation azimuth angle of the turntable 27 to 90°, set the observation zenith angle at this time to 10°, adjust the polarization direction to 0° by the polarization modulation unit I 12, the polarization modulation unit II 15 and the polarization modulation unit III 18 controlled by the central control unit 21, collect images by the visible light camera 13, the short-wave infrared camera 16 and the long-wave infrared camera 19 in the polarization imaging system 1, transmit the polarization image to the image output unit 23 by the central control unit 21, and then transmit the polarization image to the image storage and processing unit 24 by the image output unit 23 for image storage and processing.

[0066] Then, the polarization directions are adjusted to 45°, 90° and 135° by the polarization modulation unit I 12, the polarization modulation unit II 15 and the polarization modulation unit III 18 controlled by the central control unit 21, and images are collected by the visible light camera 13, the short-wave infrared camera 16 and the long-wave infrared camera 19 in the polarization imaging system 1, respectively, and the polarization image is transmitted to the image output unit 23 by the central control unit 21, and then transmitted to the image storage and processing unit 24 by the image output unit 23 for image storage and processing.

[0067] Step 3, the central control unit 21 controls the turntable control unit 25 to rotate the turntable 27, adjusts the observation azimuth angle of the turntable 27 to 180°, and sets the observation zenith angle at this time to 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, and 90° respectively, and repeats other steps in Step 2 respectively.

[0068] Adjust the observation azimuth angle of the turntable 27 to 270°, and set the observation zenith angle at this time to 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, and 90° respectively, and repeat other steps in Step 2 respectively.

[0069] Step 4, contact the local ecological environment monitoring station, and when the solar zenith angle increases or decreases by 10°, use the unmanned aerial vehicle to carry out repeated flight with the device, reach the same area, and repeat Step 2 and Step 3 respectively, and stop collecting when there is no sunlight, and store the obtained images and classify them into a red tide polarization database according to different solar zenith angles, different solar azimuth angles, different observation zenith angles, different observation azimuth angles, different wind speeds, different wind directions, different sea water temperatures, and different sea water salinities.

[0070] Step 5, use the model to match the polarization image data in the red tide polarization library, and establish a polarization bidirectional reflectance distribution function:

[0071]

[0072] In the formula, θ s is the solar zenith angle; is the solar azimuth angle; θ v is the observation zenith angle; is the observation azimuth angle; dE is the incident irradiance; dL rp is the polarization reflectance irradiance.

[0073] The sea surface wind speed and the probability distribution function of the two-dimensional rough sea surface are:

[0074]

[0075] In the formula, S up is the slope of the inclined microplane upwind; S cross is the slope of the inclined microplane crosswind; σ up is the RMS value of the inclined microplane upwind; σ cross is the RMS value of the inclined microplane crosswind.

[0076] The relationship between the sea roughness and the wind speed is:

[0077]

[0078] The slope S of the sea surface inclined microfaceted unit in the azimuth and zenith angle reference axes x , S y The relationship with the zenith angle and the azimuth angle is:

[0079]

[0080]

[0081] The relationship between the inclination angle β of the sea surface inclined microfaceted unit and the directional slope S x , S y is:

[0082]

[0083] The relationship between the slope of the headwind direction and the crosswind direction and S x , S y is:

[0084]

[0085] The sunlight is reflected by the red tide and has a polarization characteristic. The polarized light is decomposed into s-polarized component and p-polarized component by using the Fresnel reflection equation, and the relationship is:

[0086]

[0087]

[0088] In the formula, r s is the reflection coefficient of the s-polarized component; r p is the reflection coefficient of the p-polarized component; n1 is the air refractive index; n2 is the red tide refractive index; θ i is the solar incidence angle; and θ t is the refraction angle.

[0089] In the formula, n1 is the air refractive index.

[0090]

[0091] The seawater refractive index formula is:

[0092]

[0093] In the formula, p is the air pressure; T is the temperature; and λ is the wavelength.

[0094] By combining the above formulas, the relationship between the polarization reflectivity and the degree of polarization is finally obtained as:

[0095]

[0096]

[0097] where R p,rt (θ s ,θ v ,φ v ,φ wind ,n rt ,v) is the polarized reflectance of the red tide p-polarization component; R S,rt (θ s ,θ v ,φ v ,φ wind ,n rt ,v) is the polarized reflectance of the red tide s-polarization component; r p,rt is the reflectance of the red tide p-polarization component; r s,rt is the reflectance of the red tide s-polarization component; and p is the degree of polarization.

[0098] The measured data collected on the same day is taken as the simulation parameter to be brought into the formula to solve the polarized reflectance and the degree of polarization, and to be matched with the measured data. Confidence is used for verification, and the confidence formula is:

[0099]

[0100] In the formula, M is the confidence, R s and R a respectively represent the simulation value and the known value of the red tide polarization database. If the confidence is higher than 60%, the model is considered to be accurate, otherwise it is considered to be inaccurate. Secondary modeling is performed to increase the authenticity of the model, linear fitting is performed using the measured data, and a linear regression model is used to establish the relationship between the independent variable and the dependent variable. The linear regression model formula is:

[0101]

[0102] where Y p is the dependent variable; X p1 , X p2 , X p3 , X p4 , X p5 , and X p6 are the main interference conditions in the simulation and measured data as independent variables; is the main interference weight in the simulation and measured data. The greater the weight, the greater the influence of a certain interference condition on the final simulation data, and vice versa. The model after secondary modeling is verified by confidence, and the confidence is higher than 60%, which is considered to be an accurate model.

[0103] It is to be understood that the present application is described by way of example only, and that modifications or alterations can be made to the features and embodiments described without departing from the spirit and scope of the application. In addition, modifications can be made to the features and embodiments described to accommodate specific situations and materials without departing from the spirit and scope of the application. Accordingly, the application is not limited to the specific embodiments disclosed herein, but rather, the scope of the application includes all embodiments falling within the scope of the claims.

Claims

1. A method for collecting a red tide polarization database based on a polarization two-way reflection model, characterized in that: The device comprises a polarization imaging system (1) and a polarization database acquisition system (2), the polarization imaging system (1) acquires polarization images in visible light, short-wave infrared and long-wave infrared bands, the polarization imaging system (1) comprises a light splitting prism I (11), a polarization modulation unit I (12), a visible light camera (13), a light splitting prism II (14), a polarization modulation unit II (15), a short-wave infrared camera (16), a mirror (17), a polarization modulation unit III (18) and a long-wave infrared camera (19), the light splitting prism I (11), the light splitting prism II (14) and the mirror (17) are arranged on the same optical axis; the polarization modulation unit I (12) and the visible light camera (13) are sequentially arranged in the light beam transmission direction of the light splitting prism I (11); the polarization modulation unit II (15) and the short-wave infrared camera (16) are sequentially arranged in the light beam transmission direction of the light splitting prism II (14); the polarization modulation unit III (18) and the long-wave infrared camera (19) are sequentially arranged in the light beam reflection direction of the mirror (17); The polarization database acquisition system (2) performs image output, storage and processing on the polarization images acquired by the polarization imaging system (1), the polarization database acquisition system (2) comprises a central control unit (21), an image output unit (23) and an image storage and processing unit (24), the polarization images acquired by the polarization imaging system (1) are transmitted to the image storage and processing unit (24) through the central control unit (21) and the image output unit (23); The following steps are sequentially performed, Step one, when the red tide occurs, the wind speed, wind direction, seawater temperature and seawater salinity are monitored by an ecological environment monitoring station, the red tide area is divided according to different wind speed, wind direction, seawater temperature and seawater salinity, and the image of each area is acquired by using a UAV carrying a red tide polarization database acquisition device based on a polarization bidirectional reflection model; Step two, the real-time position information is confirmed by using a GPS positioning unit (26), the real-time solar zenith angle and azimuth angle are recorded, the turntable (27) is rotated by controlling the turntable control unit (25) through the central control unit (21), the observation azimuth angle is adjusted to 90°, and the observation zenith angle at this time is set to 10°; the polarization directions are sequentially adjusted to 0°, 45°, 90° and 135° by controlling the polarization modulation unit I (12), the polarization modulation unit II (15) and the polarization modulation unit III (18) through the central control unit (21), the images are acquired by using the visible light camera (13), the short-wave infrared camera (16) and the long-wave infrared camera (19) in the polarization imaging system (1), the polarization images are transmitted to the image output unit (23) by the central control unit (21), and the image storage and processing unit (24) is used for image storage and processing by the image output unit (23). Step three, the central control unit (21) controls the turntable control unit (27) to rotate the turntable (27) to adjust the observation azimuth angle to 180°, and set the observation zenith angle at this time to 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90° respectively, repeat the operation of step two to store and process the image; Adjust the observation azimuth angle of the turntable (27) to 270°, and set the observation zenith angle at this time to 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90° respectively, repeat the operation of step two to store and process the image; Step four, use the ecological environment monitoring station to monitor the solar zenith angle every 10°, use the unmanned aerial vehicle to carry out the red tide polarization database acquisition device based on the polarization two-way reflection model, and repeat the steps two and three in the same area respectively until there is no sunlight to stop collecting, and store the obtained image and classify it according to the solar zenith angle, solar azimuth angle, observation zenith angle, observation azimuth angle, wind speed, wind direction, sea water temperature and sea water salinity to edit the red tide polarization database; Step five, use the model to match the data of the polarization image in the red tide polarization library, and establish the polarization bidirectional reflection distribution function: where θs s is the solar zenith angle; is the solar azimuth angle; θ v is the observed zenith angle; is the observed azimuth angle; dE is the incident irradiance; dL rp is the polarized reflected irradiance; The probability distribution function of sea surface wind speed and two-dimensional rough sea surface is: where S up is the slope of the tilted microfacets against the wind; S cross is the slope of the tilted microfacets against the crosswind; σ up is the RMS value of the tilted microfacets against the wind; σ cross is the RMS value of the tilted microfacets against the crosswind; The relationship between sea water roughness and wind speed v is: The sea surface tilt facet unit has a slope S in the azimuth and zenith angle reference axes x , S y The relationship with the zenith angle and the azimuth angle is: The relationship between the tilt angle β of the sea surface tilt microfacet element and the directional slope S is: x , y ​ where the slope of the crosswind wind direction and the crosswind wind direction are related by S x , S y ​ wherein is the azimuth of the sea wind direction; The sunlight reflected by red algae has polarization characteristics, and the polarized light is decomposed into s polarization component and p polarization component by using Fresnel reflection equation, and the relationship is: where r s is the reflection coefficient for s-polarized component; r p is the reflection coefficient for p-polarized component; n1 is the air refractive index; n2 is the red tide refractive index; θ i is the solar incident angle; θ t is the refraction angle; The air refractive index formula is: The sea water refractive index formula is: Wherein, p is air pressure; T is temperature; λ is wavelength; By combining the above formulas, the relationship between the polarization reflectivity and the polarization degree is finally obtained: where R p,rt (θ s ,θ v ,φ v ,φ wind ,n rt ,v) is the polarized reflectance of the red tide p-polarized component; R S,rt (θ s ,θ v ,φ v ,φ wind ,n rt ,v) is the polarized reflectance of the red tide s-polarized component; r p,rt is the reflectance of the red tide p-polarized component; and r s,rt is the reflectance of the red tide s-polarized component; p is the degree of polarization; The measured data collected in the steps one to four on the same day is taken as the simulation parameter and brought into the formula to solve the polarization reflectivity and the polarization degree, and is matched with the measured data; The confidence is used for verification, and the confidence formula is: where M is the confidence, R s and R a represent the simulated value and the known value from the red tide polarization database, respectively. If the confidence is higher than 60%, the model is accurate, and if the confidence is lower than 60%, the model is inaccurate; Secondary modeling is carried out to increase the authenticity of the model, linear fitting is carried out by using the measured data, and the relationship between the independent variable and the dependent variable is established by using the linear regression model, and the linear regression model formula is: where Y p is the dependent variable; X p1 , X p2 , X p3 , X p4 , X p5 , X p6 are the independent variables; and is the dependent variable; X p1 , X p2 , X p3 , X p4 , X p5 , X p6 are the independent variables; and is the dependent variable; X p1 , X p2 , X p3 , X p4 , X p5 , X p6 are the independent variables; and 2. The red tide polarization database acquisition method based on the polarization two-way reflection model according to claim 1, characterized in that: The polarization database acquisition system (2) further comprises a turntable control unit (25), a GPS positioning unit (26) and a turntable (27), the GPS positioning unit (26) feeds back real-time position information to the turntable control unit (25), and the turntable control unit (25) is controlled by the central control unit (21) to track and rotate the turntable (27).

3. The red tide polarization database acquisition method based on the polarization two-way reflection model according to claim 1, characterized in that: The polarization database acquisition system (2) further comprises a power supply unit (22) for supplying power to the central control unit (21), the image output unit (23), the image storage and processing unit (24), the turntable control unit (25), the GPS positioning unit (26) and the turntable (27).

4. The red tide polarization database acquisition method based on the polarization two-way reflection model according to claim 1, characterized in that: The central control unit (21) controls the polarization directions of the polarization modulation unit I (12), the polarization modulation unit II (15), and the polarization modulation unit III (18). The central control unit (21) controls the polarization directions of the polarization modulation unit I (12), the polarization modulation unit II (15), and the polarization modulation unit III (18).

Images