Visible light camera for high-sensitivity detection of space dark and weak target

Abstract

The utility model discloses a visible light camera for high-sensitivity detection of a space dark and weak target, relates to the field of space optical loads, and solves the problems that an existing detection system is small in field angle, has central obscuration, is affected in imaging effect, is poor in detection capability and the like. The optical system comprises ten full spherical lenses, a diaphragm surface and an imaging target surface, a light beam sequentially passes through the first positive lens, the second negative lens, the third positive lens, the fourth positive lens, the diaphragm surface, the fifth negative lens, the sixth positive lens, the seventh positive lens, the eighth negative lens, the ninth positive lens and the tenth negative lens and then is imaged on the imaging target surface. According to the utility model, the visible light wave band is adopted to detect a space target, which is easy to detect and is also beneficial to image processing; the F number of the system is low, the light incoming amount of the optical system is high, the signal-to-noise ratio is high, and target recognition is facilitated; the field angle of the system is large, and large-range monitoring of space faint targets can be achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to space optical load field, concretely relates to a visible light camera for space dim and weak target high sensitivity detection. BACKGROUND

[0002] At present, the world's major space powers realize that space resources have important significance for national military security and national economic development, and continuously promote the development of space target detection technology. Space targets generally include satellites, space debris and asteroids, etc. The target size is very small, the detection distance is far, and the target reflection energy is weak, so it is called dim and weak target. The detection of space dim and weak target includes ground-based detection system and space-based detection system. The ground-based detection system is mature in technology, but is affected by weather, time, etc. The detection efficiency is very limited. The space-based detection system is carried on the satellite platform, is not affected by weather environment, geographical location, etc. It has the great advantages of all-weather and high sensitivity. Most of the space-based space target detection systems at home and abroad adopt Cassegrain structure form, which has small field of view angle and central obstruction, and the imaging effect is affected. When target identification is carried out, the utilization rate is low. Some space-based space target detection systems adopt transmission type structure, but the detection capacity is poor, and only 13 magnitude target detection capacity can be realized.

[0003] Therefore, the utility model provides a visible light camera for space dim and weak target high sensitivity detection, solves the problem of realizing high sensitivity detection of dim and weak target with equivalent 15 magnitude under the equivalent 21 magnitude complex sky background, and can realize large field of view range monitoring, and the overall structure is lighter. UTILITY MODEL CONTENTS

[0004] The utility model discloses a visible light camera for space dim and weak target high sensitivity detection, which solves the problem of small field of view angle and central obstruction of the existing detection system, and the imaging effect is affected, and the problem of poor detection capacity.

[0005] A visible light camera for space dim and weak target high sensitivity detection, comprising ten global surface lenses, an aperture plane and an imaging target plane, wherein the light beam is sequentially imaged on the imaging target plane after passing through the first positive lens, the second negative lens, the third positive lens, the fourth positive lens, the aperture plane, the fifth negative lens, the sixth positive lens, the seventh positive lens, the eighth negative lens, the ninth positive lens and the tenth negative lens.

[0006] The first positive lens has a refractive index of 1.45-1.55, a focal length of 370-390 mm and a central thickness of 25-30 mm.

[0007] The second negative lens has a refractive index of 1.65-1.75, a focal length of -115 to -135 mm and a central thickness of 10-15 mm.

[0008] The third positive lens material has a refractive index of 1.55-1.6, a focal length of 170-190 mm, and a central thickness of 23-27 mm;

[0009] The fourth positive lens material has a refractive index of 1.55-1.6, a focal length of 150-170 mm, and a central thickness of 21-26 mm;

[0010] The fifth negative lens material has a refractive index of 1.8-1.85, a focal length of -130--150 mm, and a central thickness of 10-15 mm;

[0011] The sixth positive lens material has a refractive index of 1.9-1.95, a focal length of 260-280 mm, and a central thickness of 10-15 mm;

[0012] The seventh positive lens material has a refractive index of 1.4-1.45, a focal length of 140-160 mm, and a central thickness of 15-20 mm;

[0013] The eighth negative lens material has a refractive index of 1.63-1.68, a focal length of -60--80 mm, and a central thickness of 10-15 mm;

[0014] The ninth positive lens material has a refractive index of 1.85-1.9, a focal length of 140-160 mm, and a central thickness of 18-23 mm;

[0015] The tenth negative lens material has a refractive index of 1.87-1.92, a focal length of -2080--2100 mm, and a central thickness of 10-15 mm.

[0016] The utility model discloses the beneficial effect of:

[0017] 1. The visible light camera adopts visible light band to detect space target, which is easy to detect and beneficial to image processing.

[0018] 2. The F number of the visible light camera is low, the light amount of the optical system is high, the signal-to-noise ratio is high, and target recognition is facilitated.

[0019] 3. The field angle of the visible light camera is large, and wide-range monitoring of space dark and weak targets can be realized.

[0020] 4. The visible light camera can realize the detection ability of 15 magnitude targets under 21 magnitude sky background, has strong detection ability, and provides real-time data support for space debris research and spacecraft collision warning of the country. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The optical structure diagram of the visible light camera for high-sensitivity detection of space dim and weak targets is described in the utility model;

[0022] Figure 2 The point list diagram of the visible light camera is described in the utility model;

[0023] Figure 3 The energy concentration degree schematic diagram of the visible light camera is described in the utility model;

[0024] Figure 4 The field curvature distortion diagram of the visible light camera is described in the utility model;

[0025] Figure 5 The vertical axis chromatic aberration diagram of the visible light camera is described in the utility model. DETAILED DESCRIPTION

[0026] In combination Figures 1 to 5 In combination, a visible light camera for high-sensitivity detection of space dim and weak targets is described in the embodiment, and the system is a transmission type structure; the system comprises a first positive lens L1, a second negative lens L2, a third positive lens L3, a fourth positive lens L4, a fifth negative lens L5, a sixth positive lens L6, a seventh positive lens L7, an eighth negative lens L8, a ninth positive lens L9, a tenth negative lens L10, an aperture plane M and an imaging target plane;

[0027] The system described in the embodiment is composed of ten global surface lenses, the first positive lens L1 has a refractive index of 1.45-1.55, a focal length of 370mm-390mm and a center thickness of 25mm-30mm;

[0028] The second negative lens L2 has a refractive index of 1.65-1.75, a focal length of -115mm--135mm and a center thickness of 10mm-15mm;

[0029] The third positive lens L3 has a refractive index of 1.55-1.6, a focal length of 170mm-190mm and a center thickness of 23mm-27mm;

[0030] The fourth positive lens L4 has a refractive index of 1.55-1.6, a focal length of 150mm-170mm and a center thickness of 21mm-26mm;

[0031] The material refractive index of the fifth negative lens L5 is between 1.8 and 1.85, the focal length is between -130mm and -150mm, and the central thickness is between 10mm and 15mm;

[0032] The material refractive index of the sixth positive lens L6 is between 1.9 and 1.95, the focal length is between 260mm and 280mm, and the central thickness is between 10mm and 15mm;

[0033] The material refractive index of the seventh positive lens L7 is between 1.4 and 1.45, the focal length is between 140mm and 160mm, and the central thickness is between 15mm and 20mm;

[0034] The material refractive index of the eighth negative lens L8 is between 1.63 and 1.68, the focal length is between -60mm and -80mm, and the central thickness is between 10mm and 15mm;

[0035] The material refractive index of the ninth positive lens L9 is between 1.85 and 1.9, the focal length is between 140mm and 160mm, and the central thickness is between 18mm and 23mm;

[0036] The material refractive index of the tenth negative lens L10 is between 1.87 and 1.92, the focal length is between -2080mm and -2100mm, and the central thickness is between 10mm and 15mm;

[0037] In the embodiment, the air gap between the first positive lens L1 and the second negative lens L2 is between 50mm and 55mm;

[0038] The air gap between the second negative lens L2 and the third positive lens L3 is between 1mm and 5mm;

[0039] The air gap between the third positive lens L3 and the fourth positive lens L4 is between 5mm and 10mm;

[0040] The air gap between the fourth positive lens L4 and the fifth negative lens L5 is between 1mm and 5mm, and the stop plane M of the optical system between the fourth positive lens L4 and the fifth negative lens L5 limits the imaging light beam;

[0041] The air gap between the fifth negative lens L5 and the sixth positive lens L6 is between 5mm and 10mm;

[0042] The air gap between the sixth positive lens L6 and the seventh positive lens L7 is between 1mm and 5mm;

[0043] The air gap between the seventh positive lens L7 and the eighth negative lens L8 is between 1mm and 5mm;

[0044] The air gap between the eighth negative lens L8 and the ninth positive lens L9 is between 15mm and 20mm.

[0045] The air gap between the ninth positive lens L9 and the tenth negative lens L10 is between 47mm and 52mm.

[0046] The distance between the tenth negative lens L10 and the imaging target surface is between 25mm and 30mm.

[0047] The optimal use state is shown in Table 1.

[0048] Table 1

[0049]

[0050] The F number of the visible light camera described in the embodiment is between 1.7 and 1.9, the imaging spectral range is between 450nm and 750nm, and the detection capability of a 15 magnitude target under a 21 magnitude sky background can be achieved.

[0051] The imaging spectral range of the visible light camera described in the embodiment is 450nm to 750nm, the focal length is 220mm, the F number is 1.83, the field of view is greater than 9°x9°, and the total optical length is less than 355mm. The system can achieve a signal-to-noise ratio greater than 5 when detecting a 15 magnitude target under a 21 magnitude sky background, and the overall weight of the machine is less than 18kg. Through networking, large-scale, high-sensitivity, and high-frequency detection of dark and weak space targets can be achieved, providing high real-time data support for China's space debris research and spacecraft collision warning.

[0052] As shown in Figures 2 to 5 the imaging quality analysis results using the visible light camera described in the embodiment are as follows: Figure 1 is a point column diagram, the size of the diffraction spot in the full field of view range is less than the size of the detector pixel, and the imaging quality is good; Figure 2 is an energy concentration degree, the energy concentration degree in 3x3 pixels is greater than 90%; Figure 3 is a field curvature distortion diagram, the distortion is less than 0.12%, the distortion is small, and the use requirement is met; Figure 4 is an axial chromatic aberration diagram; the axial chromatic aberration of the system is less than 2μm, which is conducive to the extraction and identification of star points.

[0053] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the description.

[0054] The above-described embodiments only express several implementation manners of the utility model, the description is more specific and detailed, but can not therefore be understood as the limitation of the utility model patent range. It should be pointed out that for ordinary skilled person in the art, without departing from the utility model concept, several modifications and improvements can be made, which belong to the protection range of the utility model. Therefore, the protection range of the utility model patent should be subject to the appended claims.

Claims

1. A visible light camera for high-sensitivity detection of spatially dim and weak targets, characterized in that it comprises: It comprises ten global surface lenses, diaphragm surface (M) and imaging target surface; the light beam is sequentially received by the imaging target surface after the first positive lens (L1), the second negative lens (L2), the third positive lens (L3), the fourth positive lens (L4), the diaphragm surface (M), the fifth negative lens (L5), the sixth positive lens (L6), the seventh positive lens (L7), the eighth negative lens (L8), the ninth positive lens (L9) and the tenth negative lens (L10). The first positive lens (L1) has a material refractive index of 1.45-1.55, a focal length of 370-390 mm, and a central thickness of 25-30 mm. The second negative lens (L2) has a material refractive index of 1.65-1.75, a focal length of -115--135 mm, and a central thickness of 10-15 mm. The third positive lens (L3) has a material refractive index of 1.55-1.6, a focal length of 170-190 mm, and a central thickness of 23-27 mm. The fourth positive lens (L4) has a material refractive index of 1.55-1.6, a focal length of 150-170 mm, and a central thickness of 21-26 mm. The fifth negative lens (L5) has a material refractive index of 1.8-1.85, a focal length of -130--150 mm, and a central thickness of 10-15 mm. The sixth positive lens (L6) has a material refractive index of 1.9-1.95, a focal length of 260-280 mm, and a central thickness of 10-15 mm. The seventh positive lens (L7) has a material refractive index of 1.4-1.45, a focal length of 140-160 mm, and a central thickness of 15-20 mm. The eighth negative lens (L8) has a material refractive index of 1.63-1.68, a focal length of -60--80 mm, and a central thickness of 10-15 mm. The ninth positive lens (L9) has a material refractive index of 1.85-1.9, a focal length of 140-160 mm, and a central thickness of 18-23 mm. The tenth negative lens (L10) has a material refractive index of 1.87-1.92, a focal length of -2080--2100 mm, and a central thickness of 10-15 mm.

2. The visible light camera for high-sensitivity detection of dim and weak targets in space according to claim 1, characterized in that: The F number of the visible light camera is 1.7-1.9, the field of view angle is greater than 9°x9°, the imaging spectral range is 450-750 nm, and the total length of the optical system is less than 355 mm.

3. The visible light camera for high-sensitivity detection of dim and weak targets in space according to claim 1, characterized in that: The air gap between the first positive lens (L1) and the second negative lens (L2) is 50-55 mm.

4. The visible light camera for high-sensitivity detection of dim and weak targets in space according to claim 1, characterized in that: The air gap between the second negative lens (L2) and the third positive lens (L3) is 1-5 mm.

5. The visible light camera for high-sensitivity detection of dim and weak targets in space according to claim 1, characterized in that: The air gap between the third positive lens (L3) and the fourth positive lens (L4) is 5-10 mm.

6. The visible light camera for high-sensitivity detection of dim and weak targets in space according to claim 1, characterized in that: The air gap between the fourth positive lens (L4) and the fifth negative lens (L5) is between 1mm and 5mm, and the stop plane (M) of the optical system between the fourth positive lens (L4) and the fifth negative lens (L5) limits the imaging beam.

7. The visible light camera for high-sensitivity detection of dim and weak targets in space according to claim 1, characterized in that: The air gap between the fifth negative lens (L5) and the sixth positive lens (L6) is between 5mm and 10mm.

8. The visible light camera for high-sensitivity detection of dim and weak targets in space according to claim 1, characterized in that: The air gap between the sixth positive lens (L6) and the seventh positive lens (L7) is between 1mm and 5mm.

9. The visible light camera for high-sensitivity detection of dim and weak targets in space according to claim 1, characterized in that: The air gap between the seventh positive lens (L7) and the eighth negative lens (L8) is between 1mm and 5mm.

10. The visible light camera for high-sensitivity detection of dim and weak targets in space according to claim 1, characterized in that: The air gap between the eighth negative lens (L8) and the ninth positive lens (L9) is between 15mm and 20mm; the air gap between the ninth positive lens (L9) and the tenth negative lens (L10) is between 47mm and 52mm; and the distance between the tenth negative lens (L10) and the imaging target surface is between 25mm and 30mm.

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