Method for measuring the removable obscuration ratio of a solar diffuse reflectance panel measuring telescope

Abstract

The present application belongs to the field of optical measurement, and particularly relates to a method for measuring the removable object blocking aperture ratio of a solar diffuse reflection plate measuring telescope, which comprises the following steps: s1) placing a diffuse reflection plate in front of the full aperture of the telescope; s2) tilting the diffuse reflection plate to a first state, and obtaining the full aperture response gray scale and the blocked aperture response gray scale in the first state by adjusting the different positions of the removable object in front of the telescope; s3) tilting the diffuse reflection plate to a second state, and obtaining the full aperture response gray scale and the blocked aperture response gray scale in the second state by adjusting the different positions of the removable object in front of the telescope; and s4) calculating the removable object blocking aperture ratio of the telescope according to the full aperture response gray scale and the blocked aperture response gray scale of the diffuse reflection plate in the two tilted states.

Description

Technical Field

[0001] This invention belongs to the field of optical measurement, and particularly relates to a method for measuring the aperture ratio of a telescope with removable obstructions using a solar diffuse reflector. Background Technology

[0002] In the field calibration of certain infrared radiation measurement equipment, it is necessary to know the obstruction ratio of the telescope aperture, such as the aperture of the lens cap opening or the portion of the aperture obstructed by the lens. Because the incident light angles corresponding to different pixels are different, the entrance pupils do not completely coincide. Simultaneously, the diffuser is not entirely at the entrance pupil position. For the same aperture angle, different pixels can yield different aperture obstruction ratios, requiring individual area proportions for each pixel. Calculating the aperture obstruction ratio through physical measurements and design drawings is complex and does not accurately reflect the actual obstruction ratio, nor can its correctness be verified. A more reliable and accurate measurement method is needed. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and to propose a method for measuring the aperture ratio of a telescope with removable obstructions using a solar diffuse reflector.

[0004] To achieve the above objectives, the present invention proposes a method for measuring the aperture ratio of a telescope obstructed by a removable object using a solar diffuse reflector, the method comprising:

[0005] Step s1) Place a diffuser in front of the full aperture of the telescope;

[0006] Step s2) Tilt the diffuse reflector to the first state, and obtain the full aperture response grayscale and the obstructed aperture response grayscale in the first state by adjusting the different positions of the removable object in front of the telescope.

[0007] Step s3) Tilt the diffuse reflector to the second state, and obtain the full aperture response grayscale and the obstructed aperture response grayscale in the second state by adjusting the different positions of the removable object in front of the telescope.

[0008] Step s4) Calculate the removable object obstruction aperture ratio of the telescope based on the full aperture response grayscale and obstruction aperture response grayscale under the two tilt states of diffuse reflection.

[0009] As an improvement to the above method, the diffuse reflector can completely fill the field of view.

[0010] As an improvement to the above method, step s2) specifically includes:

[0011] Tilt the diffuse reflector to the first state;

[0012] The telescope was set to full aperture, and the first response grayscale D of the full aperture was obtained by measuring the infrared detection image. h1 ;

[0013] Adjust the removable object in front of the telescope to the position to be measured, and obtain the first response grayscale D of the obstructed aperture by measuring the infrared detection image. t1 .

[0014] As an improvement to the above method, step s3) specifically includes:

[0015] Tilt the diffuse reflector to the second state;

[0016] The telescope was set to full aperture, and the second response grayscale D of the full aperture was obtained by measuring the infrared detection image. h2 ;

[0017] Adjust the removable object in front of the telescope to the position to be measured, and obtain the second response grayscale D of the obstructed aperture by measuring the infrared detection image. t2 .

[0018] As an improvement to the above method, step s4) specifically includes:

[0019] Based on the first response grayscale D of the full aperture h1 Full aperture second response grayscale D h2 And the first response grayscale D of the occluded aperture t1 , occlusion aperture, second response grayscale D t2 The aperture ratio S of the telescope with removable obstructions is obtained according to the following formula. t :

[0020]

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] 1. The method of the present invention does not require physical measurement of the obstruction and the optical aperture of the telescope, and does not need to consider the influence of the secondary mirror and the support mechanism, and can obtain the aperture obstruction ratio of each pixel.

[0023] 2. The method of the present invention can also be used for the accurate measurement of the occlusion ratio of removable or variable-diameter obstructions in other optical devices. Attached Figure Description

[0024] Figure 1 This is a flowchart of the method for measuring the aperture ratio of a telescope obstructed by a removable object using a solar diffuse reflector, according to the present invention. Detailed Implementation

[0025] Due to the location of the exposed aperture and the design and manufacturing process of the equipment lens, the proportion of the exposed aperture of the blackbody for each pixel may be different. However, it is a quantity that is only related to the structure of the optical-mechanical system and can be considered a relatively constant quantity. Therefore, after a precise measurement, it is not necessary to repeat the measurement during use.

[0026] The design concept of this invention is as follows: A large-area diffuser is placed in front of the full aperture of the telescope lens, completely filling the field of view. Rotating the diffuser results in two states:

[0027]

[0028] Among them, D h1 and D h2 These are the grayscale values ​​of the state responses of the two diffuse reflectors, L. t Let denot be the solar brightness, ρ(v1,w1) and ρ(v2,w2) be the bidirectional reflectivity of the two diffuse reflector states, respectively, a be the radiation of the diffuse reflector itself and the reflected environment, and K and c be the slope and intercept of the linear response model, respectively.

[0029] For the percentage of the full-aperture lens cap opening area or the percentage of the remaining area obstructed by the aperture of the lens obstruction, St, there are

[0030]

[0031] Among them, D t1 and D t2 These represent the grayscale values ​​of the state responses of the two diffuse reflectors, L. t For solar brightness, L g For lens cap brightness, S t This represents the percentage of the area of ​​the opening diameter.

[0032] Solving equations (1) and (2) simultaneously, we get...

[0033]

[0034] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0035] Example

[0036] like Figure 1 As shown, this embodiment includes the following steps:

[0037] Step s1) Place a diffuser in front of the full aperture of the telescope;

[0038] Step s2) Tilt the diffuse reflector to the first state, and obtain the full aperture response grayscale and the obstructed aperture response grayscale in the first state by adjusting the different positions of the removable object in front of the telescope; specifically including:

[0039] Tilt the diffuse reflector to the first state;

[0040] The telescope was set to full aperture, and the first response grayscale D of the full aperture was obtained by measuring the infrared detection image. h1 ;

[0041] Adjust the removable object in front of the telescope to the position to be measured, and obtain the first response grayscale D of the obstructed aperture by measuring the infrared detection image. t1 .

[0042] Step s3) Tilt the diffuse reflector to the second state, and obtain the full aperture response grayscale and the obstructed aperture response grayscale in the second state by adjusting the different positions of the removable object in front of the telescope; specifically including:

[0043] Tilt the diffuse reflector to the second state;

[0044] The telescope was set to full aperture, and the second response grayscale D of the full aperture was obtained by measuring the infrared detection image. h2 ;

[0045] Adjust the removable object in front of the telescope to the position to be measured, and obtain the second response grayscale D of the obstructed aperture by measuring the infrared detection image. t2 .

[0046] Step s4) Based on the full-aperture response grayscale and the obstruction aperture response grayscale under the two tilt states of diffuse reflection, calculate the removable object obstruction aperture ratio of the telescope, specifically including:

[0047] Based on the first response grayscale D of the full aperture h1 Full aperture second response grayscale D h2 And the first response grayscale D of the occluded aperture t1 , occlusion aperture, second response grayscale D t2 S is obtained according to the following formula. t :

[0048]

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for measuring the aperture ratio of a telescope obstructed by a removable object using a solar diffuse reflector, the method comprising: Step s1) Place a diffuser in front of the full aperture of the telescope; Step s2) Tilt the diffuse reflector to the first state, and obtain the full aperture response grayscale and the obstructed aperture response grayscale in the first state by adjusting the different positions of the removable object in front of the telescope. Step s3) Tilt the diffuse reflector to the second state, and obtain the full aperture response grayscale and the obstructed aperture response grayscale in the second state by adjusting the different positions of the removable object in front of the telescope. Step s4) Calculate the removable object obstruction aperture ratio of the telescope based on the full aperture response grayscale and obstruction aperture response grayscale under the two tilt states of diffuse reflection.

2. The method for measuring the aperture ratio of a telescope with a removable obstruction using a solar diffuse reflector according to claim 1, characterized in that, The diffuse reflector can completely fill the field of view.

3. The method for measuring the aperture ratio of a telescope with a removable obstruction using a solar diffuse reflector according to claim 1, characterized in that, Step s2) specifically includes: Tilt the diffuse reflector to the first state; The telescope was set to full aperture, and the first response grayscale D of the full aperture was obtained by measuring the infrared detection image. h1 ; Adjust the removable object in front of the telescope to the position to be measured, and obtain the first response grayscale D of the obstructed aperture by measuring the infrared detection image. t1 .

4. The method for measuring the aperture ratio of a telescope with a removable obstruction using a solar diffuse reflector according to claim 3, characterized in that, Step s3) specifically includes: Tilt the diffuse reflector to the second state; The telescope was set to full aperture, and the second response grayscale D of the full aperture was obtained by measuring the infrared detection image. h2 ; Adjust the removable object in front of the telescope to the position to be measured, and obtain the second response grayscale D of the obstructed aperture by measuring the infrared detection image. t2 .

5. The method for measuring the aperture ratio of a telescope with a removable obstruction using a solar diffuse reflector according to claim 4, characterized in that, Step s4) specifically includes: Based on the first response grayscale D of the full aperture h1 Full aperture second response grayscale D h2 And the first response grayscale D of the occluded aperture t1 , occlusion aperture, second response grayscale D t2 The aperture ratio S of the telescope with removable obstructions is obtained according to the following formula. t :

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