A method for measuring the immersion factor of a marine radiance meter

Abstract

The present invention discloses a method for measuring the immersion factor of a marine radiance meter, belonging to the technical field of radiation value measurement, including: controlling a stable tungsten halogen lamp to irradiate towards a calibration container below the calibration container, the bottom of the calibration container being a diffusive transmission plate to generate a uniform light field, and the calibration container being filled with ultrapure water; first measuring the radiance value when the optical window of the radiance meter is exactly immersed under the water surface, and then successively discharging the ultrapure water in the calibration container to obtain the radiance value when the distance between the optical window of the radiance meter and the water surface is z i ; performing water body attenuation correction on the measured value of the radiance meter in air and extrapolating to calculate the radiance when z i = 0; calculating the refractive index of the water body and calculating the immersion factor of the radiance meter to be measured. The marine radiance meter immersion factor measuring device of the present invention avoids the problem that in theoretical calculation, only the refractive index of the optical window of the radiance meter is considered and the influence of the optical path design of different radiance meters is ignored, resulting in a large deviation between the theoretical calculation result and the actual value.

Description

Technical Field

[0001] The present invention relates to the technical field of optical measurement, and in particular to a method for measuring the immersion factor of a marine radiance meter. Background Art

[0002] A radiance meter is an instrument for measuring the radiance light field distribution. The radiometric calibration of a radiance meter is usually carried out in the laboratory air using a "standard irradiance lamp + standard reflector" or an integrating sphere light source as a standard substance to obtain the absolute radiometric calibration coefficient in air. However, when the radiance meter works in water to measure the underwater radiance light field distribution, due to the change in the refractive index of the medium (the refractive index of water is about 1.3 times that of air), compared with that in air, the transmittance and field of view angle of the optical window of the radiance meter both change in water. Therefore, the absolute radiometric calibration coefficient in air cannot be simply used, and the transmittance and field of view angle need to be corrected, which is also called immersion factor correction.

[0003] In 1976, Autsin first theoretically deduced the calculation model of the radiance immersion factor. This model only depends on the refractive index of seawater and the refractive index of the optical window of the radiance meter. The calculation formula is as follows:

[0004] .

[0005] Wherein, is the optical wave wavelength, represents the refractive index of seawater, (λ)represents the refractive index of the optical window of the radiance meter, and IF is the radiance immersion correction factor.

[0006] However, in practice, the refractive index of the optical window of the radiance meter is usually unknown, and different radiance meters have different optical path designs. The contributions of the transmittance and field of view angle to the immersion factor are also different. Therefore, there is a deviation between the theoretical calculated value and the actual value and it is unknown. Summary of the Invention

[0007] At present, the immersion factor of a radiance meter is obtained through theoretical calculation of the refractive index of the optical window of the radiance meter. However, the refractive index of the optical window of the radiance meter is usually unknown, and different radiance meters have different optical path designs. The contributions of the transmittance and field of view angle to the immersion factor are also different. Therefore, there is a large deviation between the theoretical calculated value and the actual value. To solve the above problems, the present invention proposes a method for measuring the immersion factor of a marine radiance meter, which can effectively solve the theoretical calculation error of the immersion factor caused by the unknown refractive index of the optical window and different optical path structures.

[0008] To solve the above technical problems, the present invention adopts the following technical solutions to achieve:

[0009] A method for measuring the immersion factor of a marine radiance meter includes:

[0010] Control the halogen tungsten lamp to irradiate downward towards the calibration container. The bottom of the calibration container is a diffusive transmission plate to generate a uniform light field. The calibration container is filled with ultrapure water, and the radiance meter is located above the calibration container;

[0011] Immerse the optical window of the radiance meter into the ultrapure water in the calibration container. At this time, the measured value of the radiance meter ;

[0012] Drain the ultrapure water in the calibration container successively, so that the optical window of the radiance meter is exposed to the air. Respectively obtain the measured value of the radiance meter when the distance between the optical window of the radiance meter and the water surface is during the process of draining the ultrapure water in the calibration container , until all the ultrapure water in the calibration container is drained;

[0013] Cover the optical window of the radiance meter and obtain the measured value of the radiance meter, that is, the noise value ;

[0014] Perform water body attenuation correction on to obtain the correction value :

[0015] ;

[0016] Among them, λ is the light wave wavelength, T is the temperature of the ultrapure water in the calibration container, c is the spectral attenuation coefficient of the ultrapure water;

[0017] Calculate the radiance after water body attenuation correction when , denoted as ;

[0018] Calculate the refractive index of the water body :

[0019] ;

[0020] Among them, ; , with the unit of ; , with the unit of nm; , with the unit of nm / ℃; , with the unit of ; , with the unit of ;

[0021] Calculate the immersion factor of the radiance meter :

[0022] .

[0023] In some embodiments, The calculation method is as follows:

[0024] Calculate the logarithm, and use the least squares method to fit a linear curve of the logarithm with respect to and the logarithm. Substitute into the linear curve, and the calculated radiance is .

[0025] In some embodiments, the method for obtaining the distance between the optical window of the radiance meter and the water surface is as follows:

[0026] ;

[0027] wherein, is the height of each discharge during the ultra-pure water discharge process, and d is the initial distance from the optical window of the radiance meter to the bottom of the calibration container;

[0028] Each time height of ultra-pure water is discharged, the measured values of the radiance meter are read multiple times and averaged to obtain .

[0029] In some embodiments, the method for measuring the immersion factor of the marine radiance meter is performed using a marine radiance meter immersion factor measuring device. The marine radiance meter immersion factor measuring device includes:

[0030] Base;

[0031] Load-bearing bracket, which is fixed on the base;

[0032] Radiance meter bracket, which is connected to the load-bearing bracket;

[0033] Radiance meter, which is supported on the radiance meter bracket;

[0034] Calibration container bracket, which is connected to the load-bearing bracket;

[0035] The calibration container is supported on the calibration container bracket. The top of the calibration container is open. The side wall of the calibration container is blackened to prevent light from reflecting on the inner wall. At least the optical window of the radiance meter extends into the calibration container. A drain port is provided at the lower end of the side wall of the calibration container, and a drain valve is provided in the drain port;

[0036] Diaphragm bracket, which is connected to the load-bearing bracket. A diaphragm is supported on the diaphragm bracket. The diaphragm is located below the calibration container;

[0037] Tungsten-halogen lamp bracket, which is connected to the load-bearing bracket and is located below the diaphragm bracket. The tungsten-halogen lamp is supported on the tungsten-halogen lamp bracket.

[0038] In some embodiments, a slide rail is further included. The slide rail is fixed on the load-bearing bracket, and one or more of the radiance bracket, the diaphragm bracket, and the tungsten halogen lamp bracket are slidably connected to the slide rail and fixed to the slide rail by bolts.

[0039] In some embodiments, a light-transmitting window is provided vertically on the side wall of the calibration container, and a liquid level scale is provided on the light-transmitting window.

[0040] In some embodiments, the diaphragm bracket and / or the tungsten halogen lamp bracket is a telescopic structure.

[0041] In some embodiments, the measurement method of the marine radiance meter immersion factor measurement device further includes adjusting the arm lengths of the diaphragm bracket and / or the tungsten halogen lamp bracket so that the calibration container, the diaphragm, and the tungsten halogen lamp are coaxially arranged.

[0042] In some embodiments, the measurement method of the marine radiance meter immersion factor measurement device further includes adjusting the diaphragm so that the light spot irradiated on the calibration container is consistent with the bottom surface of the calibration container.

[0043] In some embodiments, both the base and the load-bearing bracket are made of aluminum alloy, and the surfaces of the base and the load-bearing bracket are sprayed with a black coating.

[0044] Compared with the prior art, the advantages and positive effects of the present invention are:

[0045] The measurement method of the marine radiance meter immersion factor of the present invention measures the measured value of the radiance meter when the optical window of the radiance meter is immersed in the ultrapure water in the calibration container , and the measured value of the radiance meter when the optical window is in the air under the same external environment . Then, by combining the refractive index of the water body, the immersion factor of the radiance meter can be calculated. In this solution and can both be measured in the laboratory. The refractive index of the water body is related to the water temperature and the light wave wavelength and can also be calculated. Therefore, the immersion factor of the radiance meter in this solution has higher accuracy and is less affected by unknown external factors. The measurement method of the marine radiance meter immersion factor of the present invention does not require the known refractive index of the optical window of the radiance meter and the optical path structure, and thus can avoid the problem that the deviation between the radiance immersion correction factor obtained by theoretical calculation and the actual value is relatively large.

[0046] The marine radiance meter immersion factor measurement device and its measurement method of the present invention define the immersion factor of the radiance meter to be measured from the experimental process, avoiding the problem that only the refractive index of the optical window of the radiance meter is considered in theoretical calculation and the influence of the optical path design of different radiance meters is ignored, resulting in a relatively large deviation from the actual value.

[0047] This solution measures by designing a set of precise measurement devices and steps for the immersion factor of a marine radiance meter and , which is beneficial to improving and measurement accuracy, and further improving the accuracy of the calculated immersion factor of the radiance meter.

[0048] After reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become clearer. Description of the Drawings

[0049] Figure 1 is a flowchart of an embodiment of the method for measuring the immersion factor of a marine radiance meter proposed by the present invention;

[0050] Figure 2 is a schematic structural diagram of an embodiment of the measurement device used in the method for measuring the immersion factor of a marine radiance meter proposed by the present invention;

[0051] Figure 3 is a comparison diagram of the measurement results of the method for measuring the immersion factor of a marine radiance meter proposed by the present invention and the prior art. Detailed Embodiments

[0052] The following further elaborates on the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0054] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the accompanying drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0055] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] Embodiment 1: radiance refers to the luminous flux density in a certain direction within a unit area. Generally, a radiance meter is used to measure the radiance of the surface of an object.

[0057] When the radiometer is immersed in an underwater environment, due to the different optical refractive indices of air and water, the original radiometer calibration coefficient must be corrected before it can be applied to the underwater environment. This correction factor is called the immersion factor.

[0058] At present, the immersion factor of the radiometer is obtained by theoretical calculation of the refractive index of the optical window of the radiometer. However, the refractive index of the optical window of the radiometer is usually unknown and the optical path design of different radiometers is different. The transmittance and field angle also contribute differently to the immersion factor. Therefore, there is a technical problem that the theoretical calculation value deviates greatly from the actual value. In order to solve the above problem, this embodiment proposes a method for measuring the immersion factor of an ocean radiometer, such as Figure 1 As shown, including:

[0059] Control the halogen tungsten lamp to illuminate the calibration container from the bottom. The bottom of the calibration container is a diffuse transmission plate to produce a uniform light field. The calibration container is filled with ultrapure water. The radiometer is located above the calibration container. The optical window of the radiometer is immersed in the ultrapure water in the calibration container. At this time, the radiometer measures By controlling the halogen tungsten lamp to irradiate toward the calibration container from below the calibration container, the light of the halogen tungsten lamp can be evenly irradiated into the optical window of the radiometer after being diffusely transmitted through the ultrapure water in the calibration container.

[0060] The bottom of the calibration container is calibrated as a diffuse transmission plate to generate a uniform light field, which is used to eliminate the problem of uneven light transmission caused by material or process problems at the bottom of the calibration container, so that the measurement experiment can avoid errors introduced by equipment as much as possible.

[0061] The ultrapure water in the calibration container is discharged in batches so that the optical window of the radiometer is exposed to the air. The distance between the optical window of the radiometer and the water surface during the ultrapure water discharge process is obtained respectively. Radiometer measurement value , until all the ultrapure water in the calibration container is drained. In this step, the light irradiated by the tungsten halogen lamp passes through ultrapure water at different depths and is received by the optical window after passing through different distances from the water surface, thus avoiding the random error introduced by measuring a single depth.

[0062] For example, in this solution, after the optical window of the radiance meter is exposed to the air, the ultrapure water in the standard container is drained in multiple times until it is completely drained, and the drainage depth each time is of water, and the radiance meter measurement value is obtained.

[0063] Cover the optical window of the radiance meter to obtain the radiance meter measurement value, that is, the noise value .

[0064] Perform water body attenuation correction to obtain the correction value :

[0065] .

[0066] Among them, λ is the light wave wavelength, T is the temperature of the ultrapure water in the calibration container, c is the spectral attenuation coefficient of the ultrapure water.

[0067] In the formula, is the distance from the radiance meter window to the water surface, λ is the wavelength, is the height of the radiance meter from the water surface, when measuring the radiance, is the dark current of the radiance meter, that is, the noise value. Since the purpose of the present invention is to obtain the radiance values of the irradiance meter in the air and in the water at the same distance at the same time, the radiance value at the distance d in the water has been obtained, and the radiance at the distance d in the air is not suitable for direct measurement. The present invention measures the radiance value in the air at different water surface heights by continuously changing the water surface height. And the light attenuates in water following the Beer-Lambert law, that is:

[0068] .

[0069] Among them, is the light intensity after passing through the medium, is the light intensity incident on the medium, c is the spectral attenuation coefficient of the ultrapure water, z is the height of the radiance meter from the water surface. Therefore, it is necessary to perform water body attenuation correction on the radiance meter measurement value to correct it to the radiance value in the air when the water surface height is d. Therefore, according to the Beer-Lambert law, it is necessary to perform water body attenuation correction on the radiance meter measurement value after subtracting the noise value.

[0070] Calculate The radiance after water body attenuation correction is denoted as 。

[0071] Calculate the refractive index of water :

[0072] ;

[0073] Among them, ; , the unit is ; , the unit is nm; , the unit is nm / ℃; , the unit is ; , the unit is 。

[0074] Calculate the immersion factor of the radiometer :

[0075] 。

[0076] According to the geometric optics theory, the field of view of the radiometer in water and air is only related to the refractive indices of air and seawater, that is:

[0077] 。

[0078] According to Fresnel's law, the transmittance of the water-vapor interface is calculated as follows:

[0079] 。

[0080] Since the theoretical derivation model of the radiance immersion factor is: , combining the geometric optics theory and Fresnel's law, the immersion factor of the radiometer in this embodiment can be obtained 。

[0081] The method for measuring the immersion factor of the marine radiometer in this embodiment is to measure the measured value of the radiometer when the optical window of the radiometer is immersed in ultrapure water in the calibration container, and the measured value of the radiometer when the optical window is in air under the same external environment. Then, by combining the refractive index of the water body, the immersion factor of the radiometer can be calculated. In this scheme and can both be measured in the laboratory. The refractive index of the water body is related to the water temperature and the light wave wavelength and can also be calculated. Therefore, the immersion factor of the radiometer in this scheme has higher accuracy and is less affected by unknown external factors.

[0082] The method for measuring the immersion factor of this marine radiance meter does not require the calculation based on the known refractive index of the optical window and the optical path structure of the radiance meter, thus avoiding the problem of large deviation between the radiance immersion correction factor obtained by theoretical calculation and the actual value.

[0083] The marine radiance meter immersion factor measuring device and its measuring method of this application define the immersion factor of the radiance meter to be measured from the experimental process, avoiding the influence brought by different optical path designs of radiance meters only considered in theoretical calculation while neglecting the refractive index of the optical window of the radiance meter, thus avoiding the problem of large deviation from the actual value.

[0084] This solution measures by designing a set of precise marine radiance meter immersion factor measuring device and measuring steps and , which is beneficial to improving and measurement accuracy, and then improving the accuracy of the calculated immersion factor of the radiance meter.

[0085] According to the geometric optics theory, the field of view of the radiometer in water and air is only related to the refractive indices of air and water body, that is:

[0086] .

[0087] According to the Fresnel's law, the transmittance of the water-air interface is calculated as follows:

[0088] .

[0089] According to the above formula, the immersion factor of the radiance meter can be obtained:

[0090] .

[0091] In some embodiments, is calculated as:

[0092] Calculate logarithm, and use the least squares method to fit a linear curve about and logarithm. Substitute into the linear curve, and the calculated radiance is .

[0093] In some embodiments, the method for obtaining the distance from the optical window of the radiance meter to the water surface is:

[0094] .

[0095] Among them, h is the height of each discharge during the ultra-pure water discharge process, and d is the initial distance from the optical window of the radiance meter to the bottom of the calibration container.

[0096] Each discharge of ultra-pure water, the current radiance value is measured multiple times using a radiance meter and averaged to obtain .

[0097] In some embodiments, the method for measuring the immersion factor of an ocean radiance meter is performed using an ocean radiance meter immersion factor measurement device, as Figure 2 shown. The ocean radiance meter immersion factor measurement device includes: a base 11, a load-bearing bracket 12, a radiance meter bracket 13, a radiance meter 14, a calibration container bracket 15, a diaphragm bracket 16, and a tungsten halogen lamp bracket 17. The load-bearing bracket 12 is fixed on the base 11, the radiance meter 14 is supported on the radiance meter bracket 13, the calibration container bracket 15 is connected to the load-bearing bracket 12, the calibration container 18 is supported on the calibration container bracket 15, the top of the calibration container 18 is open, and its bottom is provided with a diffusing transmission plate 19. The side wall of the calibration container 18 is blackened to prevent light from reflecting on the inner wall, at least the optical window of the radiance meter extends into the calibration container 18, and a drain port is provided at the lower end of the side wall of the calibration container 18, and a drain valve 20 is provided in the drain port. The diaphragm bracket 16 is connected to the load-bearing bracket 12, a diaphragm 21 is supported on the diaphragm bracket 16, and the diaphragm 21 is located below the calibration container 18. The tungsten halogen lamp bracket 17 is connected to the load-bearing bracket 12 and is located below the diaphragm bracket 16, and a tungsten halogen lamp 22 is supported on the tungsten halogen lamp bracket 17.

[0098] The radiance meter 14 is fixed on the radiance meter bracket 13, and the radiance meter 14 is connected to a laptop computer 23 by a data acquisition line 24. The height of the calibration container 18 is not less than 50 cm, and the diameter is not less than 40 cm. The calibration container 18 is filled with ultra-pure water.

[0099] The calibration container 18 is provided with a diffusing transmission plate 19 at the bottom, and its main function is that the incident light of the light source forms a surface-uniform light source after passing through the diffusing transmission plate 19, serving as the radiance emission light source.

[0100] The water outlet is provided with a valve 20 to control the water surface height in the calibration container 18, and the ultra-pure water is stored in the container through a water pipe 27.

[0101] In some embodiments, the ocean radiance meter immersion factor measurement device further includes a slide rail 25. The slide rail 25 is fixed on the load-bearing bracket 12, and one or more of the radiance meter bracket 13, the diaphragm bracket 16, and the tungsten halogen lamp bracket 17 are slidably connected to the slide rail 25 for vertical movement and fixed to the slide rail 25 by bolts after the position is fixed.

[0102] The diaphragm 21 is fixed on the diaphragm support 16, and the diaphragm support 16 can be telescopically extended and retracted in the vertical direction along the slide rail 25, and can be adjusted to align its center with the center of the calibration container 18.

[0103] The size of the diaphragm 21 can be adjusted so that the size of the transmitted light spot is the same as the size of the calibration container 18.

[0104] In some embodiments, the diaphragm support 16 and / or the tungsten halogen lamp support 17 are telescopic structures. The tungsten halogen lamp 22 is fixed on the tungsten halogen lamp support 17. During the measurement of the immersion factor of the ocean radiance meter, it also includes adjusting the arm lengths of the diaphragm support 16 and / or the tungsten halogen lamp support 17 so that the calibration container 18, the diaphragm 21, and the tungsten halogen lamp 22 are coaxially arranged.

[0105] The tungsten halogen lamp 22 is connected to a regulated power supply 28 so that it can output with an intensity stability better than 99%.

[0106] The calibration container 18 is made of acrylic material, and its inner wall is spray-painted to form a black inner wall to minimize light scattering to the greatest extent.

[0107] In some embodiments, both the base 11 and the load-bearing support 12 are made of aluminum alloy, which not only ensures the strength of the device but also reduces the weight.

[0108] The surfaces of the base 11 and the load-bearing support 12 are sprayed with a black coating, and the aluminum alloy surfaces are all sandblasted and black anodized to minimize light reflection to the greatest extent.

[0109] The tungsten halogen lamp 22 irradiates the diffusing transmission plate 19 through the diaphragm 21 to form a uniform surface light source. The diffused transmitted light passes through water bodies of different depths and reaches the window of the radiance meter and is received by it. Therefore, when the radiance meter 14 measures the radiance at different depths, water attenuation correction needs to be performed.

[0110] In some embodiments, a light-transmitting window is provided vertically along the side wall of the calibration container 18, and a liquid level scale 26 is provided on the light-transmitting window.

[0111] The minimum scale unit of the liquid level scale 26 is millimeter, and the background is transparent, and the height of the ultrapure water liquid level in the calibration container can be observed through the scale 26.

[0112] In some embodiments, the measurement method of the ocean radiance meter immersion factor measurement device further includes adjusting the diaphragm 21 so that the light spot irradiated on the calibration container 18 is consistent with the bottom surface of the calibration container 18.

[0113] The calibration process of the radiance meter immersion factor is as follows:

[0114] (1) Fix the tungsten halogen lamp, the diaphragm, the calibration container, and the radiance meter on their respective supports.

[0115] (2) Adjust the radiance meter bracket and the diaphragm bracket so that the centers of both are collinear with the center of the calibration container.

[0116] (3) Adjust the center of the tungsten halogen lamp so that it is collinear with the center of the diaphragm.

[0117] (4) Turn on the power of the tungsten halogen lamp and preheat it for 15 - 20 minutes.

[0118] (5) Adjust the aperture of the diaphragm so that the transmitted light evenly illuminates the diffusing transmission plate.

[0119] (6) Slowly inject ultrapure water into the calibration container until it just submerges the optical window of the radiance meter. Denote the distance from the optical window to the bottom of the calibration container as d, and measure and record the water temperature T.

[0120] (7) Turn on the power of the radiance meter and preheat it for 15 - 20 minutes.

[0121] (8) Open the operation software of the radiance meter, measure 5 times or more, take the average value and denote it as .

[0122] (9) Lower the water level in the calibration container by Δz. At this time, the distance from the optical window of the radiance meter to the water surface is Δz, , measure n times, take the average value and denote it as .

[0123] (10) Repeat the above steps until all the water in the calibration container is pumped out, that is, .

[0124] (11) Cover the optical window of the radiance meter, measure the dark current 5 times or more, take the average value and denote it as .

[0125] As Figure 3 shown, it is a comparison of the experimental measurement of the radiance meter 8693 produced by German TriOS Company using the present invention and the calculation results using the Austin theoretical formula in the background technology. It can be seen that the theoretically calculated immersion factor is about 3% lower than the actual measured value.

[0126] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those of ordinary skill in the art within the essence of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for measuring the immersion factor of a marine radiance meter, characterized in that, Including: Controlling the halogen tungsten lamp to irradiate downward towards the calibration container below it. The bottom of the calibration container is a diffusive transmission plate to generate a uniform light field. The calibration container is filled with ultrapure water, and the radiance meter is located above the calibration container; The optical window of the radiance meter is immersed in the ultrapure water of the calibration container, and the measured value of the radiance meter at this time ; Drain the ultrapure water in the calibration container in sequence, so that the optical window of the radiance meter is exposed to the air, and respectively obtain the measured value of the radiance meter when the distance between the optical window of the radiance meter and the water surface is during the process of discharging the ultrapure water from the radiance meter, until all the ultrapure water in the calibration container is drained; Cover the optical window of the radiance meter to obtain the radiance meter measurement value, that is, the noise value ; Perform water body attenuation correction to obtain a correction value : ； wherein, λ is the optical wave wavelength, T is the temperature of ultrapure water in the calibration container, c is the spectral attenuation coefficient of ultrapure water; Calculation The radiance after water body attenuation correction during is denoted as Calculating the refractive index of water : ； Among them, ; , with the unit of ; , with the unit of nm; , with the unit of nm / ℃; , with the unit of ; , with the unit of ; Calculating the immersion factor of a radiance meter : 。 2. The method for measuring the immersion factor of a marine radiance meter according to claim 1, characterized in that, The calculation method is as follows: Calculate the logarithm of, and use least squares to fit a linear curve with respect to the logarithm of and . Substitute into the linear curve, and the calculated radiance is .

3. The method for measuring the immersion factor of a marine radiance meter according to claim 1, characterized in that, Distance between the optical window of the radiance meter and the water surface The acquisition method is as follows: ； wherein, is the height of each discharge during the ultra-pure water discharge process, and d is the initial distance from the optical window of the radiance meter to the bottom of the calibration container; Each discharge Ultra-pure water of a certain height, the radiance meter measurement values are read multiple times, and an average calculation is performed to obtain .

4. The method for measuring the immersion factor of a marine irradiance meter according to any one of claims 1-3, characterized in that The method for measuring the immersion factor of a marine radiance meter is measured by a measuring device for the immersion factor of a marine radiance meter. The measuring device for the immersion factor of a marine radiance meter includes: Base; Load-bearing bracket, which is fixed on the base; Radiance meter bracket, which is connected to the load-bearing bracket; Radiance meter, which is supported on the radiance meter bracket; Calibration container bracket, which is connected to the load-bearing bracket; The calibration container is supported on the calibration container bracket. The top of the calibration container is open. The side wall of the calibration container is blackened to prevent light from reflecting on the inner wall. At least the optical window of the radiance meter extends into the calibration container. A drain port is provided at the lower end of the side wall of the calibration container, and a drain valve is arranged in the drain port; Diaphragm bracket, which is connected to the load-bearing bracket. A diaphragm is supported on the diaphragm bracket, and the diaphragm is located below the calibration container; Halogen tungsten lamp bracket, which is connected to the load-bearing bracket and is located below the diaphragm bracket. The halogen tungsten lamp is supported on the halogen tungsten lamp bracket.

5. The method for measuring the immersion factor of an oceanic radiance meter according to claim 4, characterized in that, It further includes a slide rail, the slide rail is fixed on the load-bearing bracket, and one or more of the radiance meter bracket, diaphragm bracket and halogen tungsten lamp bracket are slidably connected to the slide rail and fixed to the slide rail by bolts.

6. The method for measuring the immersion factor of an oceanic radiance meter according to claim 4, wherein A light-transmitting window is left vertically on the side wall of the calibration container, and a liquid level scale is arranged on the light-transmitting window.

7. The method for measuring the immersion factor of an oceanic radiance meter according to claim 4, characterized in that, The diaphragm bracket and / or the halogen tungsten lamp bracket is a telescopic structure.

8. The method for measuring the immersion factor of a marine irradiance meter according to claim 7, wherein The measuring method of the measuring device for the immersion factor of a marine radiance meter further includes adjusting the arm lengths of the diaphragm bracket and / or the halogen tungsten lamp bracket so that the calibration container, the diaphragm and the halogen tungsten lamp are coaxially arranged.

9. The method for measuring the immersion factor of a marine radiance meter according to claim 4, wherein The measuring method of the measuring device for the immersion factor of a marine radiance meter further includes adjusting the diaphragm so that the light spot irradiated on the calibration container is consistent with the bottom surface of the calibration container.

10. The method for measuring the immersion factor of an oceanic radiance meter according to claim 4, wherein Both the base and the load-bearing bracket are made of aluminum alloy, and the surfaces of the base and the load-bearing bracket are sprayed with a black coating.

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