Detection Device and Method for Correction Coefficient of Diffraction Effect of Solar Irradiance Radiometer

Abstract

The present invention relates to a detection device for the diffraction effect correction coefficient of a solar irradiance absolute radiometer, comprising a solar simulation light source, an aperture diaphragm, a lens, a light shielding disc and a light intensity detector; the solar simulation light source illuminates the aperture diaphragm to form geometric light and diffracted light; the focal length of the lens is f, the aperture diaphragm is located at a position of 2f on the object side of the lens, and the light intensity detector is located at a position greater than 2f on the image side of the lens; the light shielding disc can be selectively located at a position of f away from the lens on the image side of the lens. The present invention also provides a detection method for the diffraction effect correction coefficient of a solar irradiance absolute radiometer, which obtains the diffraction effect correction coefficient by using experimental detection means, greatly improving the absolute measurement accuracy of the solar irradiance absolute radiometer.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and particularly to a detection device and method for a diffraction effect correction coefficient, and more particularly to a detection device and method for a diffraction effect correction coefficient of a solar irradiance absolute radiometer. Background Art

[0002] Climate change is one of the great challenges faced by the world today, and the scientific community is committed to studying the climate change mechanism. The sun is the only external energy input source of the earth and is the driving force for the formation, development and change of the ecosystem.

[0003] The Solar Irradiance Monitor (SIM) is a solar irradiance absolute radiometer. The core detector is a blackbody cavity with an ultra-high absorption ratio for incident light. The temperature change caused by the reproduction of the optical power by the electric power is measured, and the unknown optical power is calibrated by accurately measuring the equivalent electric power. The measurement target of the solar irradiance absolute radiometer is the irradiance (unit: W / m 2 ), that is, the ratio of the optical power passing through the aperture diaphragm to the area. However, when the solar radiation passes through the aperture diaphragm, a diffraction effect will occur, resulting in the inconsistency between the geometric expectation value (I1) and the actual value power (I2) of the optical power passing through the aperture diaphragm. The ratio is called the diffraction correction coefficient (D = I1 / I2), which is one of the main correction factors of the solar irradiance absolute radiometer. At present, most of the domestic and foreign methods adopt theoretical modeling calculations to obtain the diffraction effect correction coefficient of the solar irradiance absolute radiometer, and it is difficult to experimentally detect and verify the effectiveness of the calculation results.

[0004] At present, in the field of radiation metrology, the diffraction effect is difficult to measure experimentally. Research institutions at home and abroad have carried out relevant theoretical research work, and established a theoretical calculation method for the diffraction effect error factor of the solar irradiance absolute radiometer based on the SAD structure. According to the aperture diaphragm design parameters, the diffraction correction factors of different structures obtained by theoretical model calculations are usually 0.1% - 0.3%, and some even reach 0.5%. Due to the lack of experimental measurement means for the diffraction effect of the aperture diaphragm, it is impossible to evaluate the uncertainty of the theoretical correction results of the aperture diaphragm diffraction, so as to test the credibility of the theoretical calculation method.

[0005] Therefore, the prior art needs to be further improved. Summary of the Invention

[0006] The technical problem solved by the present invention is to measure the diffracted light intensity by optical means, so as to obtain the actual diffraction effect correction coefficient of the solar irradiance absolute radiometer.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A detection device for the diffraction effect correction coefficient of a solar irradiance absolute radiometer, the detection device comprising:

[0009] A solar simulation light source, an aperture diaphragm, a lens, a light blocking disc and a light intensity detector; the solar simulation light source illuminates the aperture diaphragm to form geometric light with a scattering angle of α and diffracted light with a diffraction angle of θ; the focal length of the lens is f, the aperture diaphragm is located on the object side of the lens at a position 2f away from the lens, and the light intensity detector is located on the image side of the lens at a position greater than 2f away from the lens; the light blocking disc can be selectively located on the image side of the lens at a position f away from the lens, and is used to reflect the geometric expected light formed by the geometric light passing through the lens out of the main optical path.

[0010] Preferably, the diameter of the light blocking disc is αf.

[0011] Preferably, the diameter of the light blocking disc is greater than αf and less than θf.

[0012] Preferably, the light intensity detector is a camera.

[0013] On the other hand, the present invention also proposes a detection method for the diffraction effect correction coefficient of a solar irradiance absolute radiometer, using the above detection device.

[0014] Preferably, the detection method includes the following steps:

[0015] S1: Measure and obtain the total light intensity (I2) including the geometric light and the diffracted light passing through the aperture diaphragm through the light intensity detector;

[0016] S2: Reflect the geometric expected light formed by the geometric light passing through the lens out of the main optical path by the light blocking disc, and measure and obtain the light intensity (I3) of the diffracted light passing through the aperture diaphragm through the light intensity detector;

[0017] S3: Calculate the light intensity (I1) of the geometric light: I1 = I2 - I3;

[0018] S4: Calculate the diffraction effect correction coefficient (D): D = I1 / I2.

[0019] Preferably, in step S1, the geometric light and the diffracted light converge into an imaging spot at 2f on the image side of the lens, and the imaging spot is within the field of view of the light intensity detector.

[0020] Preferably, in step S2, the diffracted light forms an equal-sized inverted image of the diffracted light at 2f on the image side of the lens.

[0021] Based on the Fraunhofer far-field diffraction principle, the present invention uses dark-field imaging technology to measure the diffraction light intensity by optical means, and obtains the diffraction effect correction coefficient of an actual solar irradiance absolute radiometer. The diffraction effect correction coefficient is obtained through experimental detection means to verify the accuracy of the theoretical model and improve the absolute measurement accuracy of the solar irradiance absolute radiometer. Description of the Drawings

[0022] Figure 1 It is a detection device for the diffraction effect correction coefficient of a solar irradiance absolute radiometer of the present invention, in which the object-image relationship of the aperture diaphragm diffraction effect is shown;

[0023] Figure 2 is in Figure 1 The detection device shown shows the use of a camera to measure the total intensity of the diffraction light and the geometric light;

[0024] Figure 3 is in Figure 1 The detection device shown shows the use of a camera to measure the diffraction light intensity.

[0025] Among them, the reference numerals include:.

[0026] Solar simulation light source 1, aperture diaphragm 2, diffraction light 3, geometric light 4, lens 5, light intensity tester 6, light blocking disc 7. Detailed Embodiments

[0027] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0028] Please refer to Figure 1 As shown, the present invention provides a detection device 10 for the diffraction effect correction coefficient of a solar irradiance absolute radiometer. The detection device includes: a solar simulation light source 1, an aperture diaphragm 2, a lens 5, a light blocking disc 7 and a light intensity detector 6.

[0029] In a specific embodiment, the solar simulation light source 1 illuminates the aperture diaphragm 2, so that geometric light 4 with a scattering angle of α and diffraction light 3 with a diffraction angle of θ are formed from the aperture diaphragm 2. The focal length of the lens 5 is f, the aperture diaphragm 2 is located on the object side of the lens 5 at a position 2f away from the lens, and the light intensity detector 6 is located on the image side of the lens 5 at a position greater than twice the focal length (2f) away from the lens 5; the light blocking disc 7 can be optionally located on the image side of the lens 5 at a position f away from the lens 5, and is used to reflect the geometric desired light formed by the lens out of the main optical path.

[0030] In a specific embodiment, at the image side 1f of the lens 5, the geometric light 4 propagating in a straight line is imaged as a first circular light spot with a diameter of αf through the aperture stop 2, and the diffracted light 3 of the aperture stop 2 is imaged as a second circular light spot with a diameter greater than αf. At the image side 2f of the lens 5, the geometric light 4 and the diffracted light 3 are imaged as an inverted image equal in size to the aperture stop 2, and the specific object-image relationship is as Figure 1 shown.

[0031] In a preferred embodiment, the light blocking disc 7 is a light blocking circular disc with a diameter of αf.

[0032] In another preferred embodiment, the light blocking disc 7 is a light blocking circular disc with a diameter greater than αf and less than θf. With this setting, the light blocking circular disc is used to reflect the geometric light 4 passing through the lens 5 to form geometric expected light out of the main optical path, without affecting the diffracted light 3.

[0033] In a specific embodiment, the light intensity detector is a camera.

[0034] Through the detection device provided by the present invention, the separation and detection of geometric light and diffracted light are realized by setting a light blocking plate, so as to obtain the diffraction effect correction coefficient of the solar irradiance absolute radiometer and improve the absolute measurement accuracy of the solar irradiance absolute radiometer.

[0035] The present invention also proposes a detection method for the diffraction effect correction coefficient of a solar irradiance absolute radiometer. The detection method includes the following steps:

[0036] S1: Measure and obtain the total light intensity (I2) including the geometric light and the diffracted light passing through the aperture stop through a light intensity detector;

[0037] S2: Reflect the geometric light passing through the lens to form geometric expected light out of the main optical path by means of a light blocking disc, and measure and obtain the light intensity (I3) of the diffracted light passing through the aperture stop through a light intensity detector;

[0038] S3: Calculate the light intensity (I1) of the geometric light: I1 = I2 - I3;

[0039] S4: Calculate the diffraction effect correction coefficient (D): D = I1 / I2.

[0040] Please refer to Figure 2 and Figure 3 shown, the aperture stop 2 is placed at the object side double focal length (2f) position of the lens 5 (focal length f).

[0041] Next, step S1 will be further described.

[0042] Illuminate the aperture stop 2 with a solar simulation light source 1 (scattering angle α). At the image side 1f of the lens 5, the geometric light 4 propagating in a straight line through the aperture stop 2 forms a circular light spot with a diameter of αf, and the diffracted light 3 of the aperture stop 2 forms a circular light spot with a diameter greater than αf. At the image side 2f of the lens 5, the geometric light 4 and the diffracted light 3 form an inverted image equal in size to the aperture stop 2. For the object-image relationship, please refer to Figure 1 as shown.

[0043] Please refer to Figure 2 , specifically, fix the camera 6 at a position on the image side greater than 2f and ensure that the imaged light spot is within the field of view of the camera 6. Use the camera 6 to measure the total light intensity (I2) of the geometric light 4 and the diffracted light 3 passing through the aperture stop 2.

[0044] Next, step S2 will be further described.

[0045] Please refer to Figure 3 , specifically, place a light shield 7 with a diameter of αf at the image side 1f position of the lens 5. At the image side 1f of the lens 5, the geometric light 4 propagating in a straight line through the aperture stop 2 forms a circular light spot with a diameter of αf. At this time, the geometric expected light is reflected out of the main optical path by the light shield 7, and an inverted image equal in size to the diffracted light will be formed at the image side 2f position of the lens 5. Use the camera 6 to measure the diffracted light intensity (I3).

[0046] Next, steps S3 and S4 will be further described.

[0047] Calculate the geometric light intensity (I1) as shown in the following formula:

[0048] I1 = I2 - I3

[0049] Furthermore, calculate the diffraction correction coefficient (D) as shown in the following formula:

[0050] D = I1 / I2

[0051] Thus, through the detection device and method provided by the present invention, the diffraction correction coefficient of the diaphragm diffraction effect of the solar irradiance absolute radiometer can be calculated.

[0052] The detection device and method for the diaphragm diffraction effect of the solar irradiance absolute radiometer provided by the present invention are based on the Fraunhofer far-field diffraction and dark-field imaging principles. The geometric light and the diffracted light are separated and detected through a light shield, so as to obtain the diffraction effect correction coefficient of the solar irradiance absolute radiometer. The diffraction effect correction coefficient is obtained by using experimental detection means, so as to verify the accuracy of the theoretical model and improve the absolute measurement accuracy of the solar irradiance absolute radiometer. Through simulation, it is further shown that the detection device and method provided by the present invention have practical application prospects.

[0053] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0054] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0055] The above specific implementation manners of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A detection device for the diffraction effect correction coefficient of a solar irradiance absolute radiometer, characterized in that, The detection device includes: a solar simulation light source, an aperture diaphragm, a lens, a light blocking disc, and a light intensity detector; the solar simulation light source illuminates the aperture diaphragm to form geometric light with a scattering angle of α and diffracted light with a diffraction angle of ɵ; the focal length of the lens is f, the aperture diaphragm is located on the object side of the lens at a position 2f away from the lens, and the light intensity detector is located on the image side of the lens at a position greater than 2f away from the lens; when the light blocking disc is located on the image side of the lens at a position f away from the lens, it is used to reflect the geometric light passing through the lens to form geometric expected light out of the main optical path.

2. The detection device according to claim 1, characterized in that The diameter of the light blocking disc is αf.

3. The detection device according to claim 1, wherein, The diameter of the light blocking disc is greater than αf and less than ɵf.

4. The detection device according to claim 1, wherein The light intensity detector is a camera.

5. A method for detecting the diffraction effect correction coefficient of an absolute radiometer for solar irradiance, characterized in that, The detection device as described in claim 1 is adopted.

6. The detection method according to claim 5, characterized in that The detection method includes the following steps: S1: Measure and obtain the total light intensity I2 including the geometric light and the diffracted light passing through the aperture diaphragm through the light intensity detector; S2: Use the light blocking disc to reflect the geometric light passing through the lens to form geometric expected light out of the main optical path, and measure and obtain the light intensity I3 of the diffracted light passing through the aperture diaphragm through the light intensity detector; S3: Calculate the light intensity I1 of the geometric light: I1 = I2 - I3; S4: Calculate the diffraction effect correction coefficient D: D = I1 / I2.

7. The detection method according to claim 6, characterized in that, In step S1, the geometric light and the diffracted light converge into an imaging spot at 2f on the image side of the lens through the lens, and the imaging spot is within the field of view of the light intensity detector.

8. The detection method according to claim 6, characterized in that, In step S2, the diffracted light forms an equal-sized inverted image of the diffracted light at 2f on the image side of the lens through the lens.

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