scholarly journals Catadioptric Optical System Design of 15-Magnitude Star Sensor with Large Entrance Pupil Diameter

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5501
Author(s):  
Yang Bai ◽  
Jianlin Li ◽  
Rongwei Zha ◽  
Ying Wang ◽  
Guangzhi Lei
Keyword(s):  
Optical System ◽  
Attitude Control ◽  
Pupil Diameter ◽  
Focal Length ◽  
Field Of View ◽  
Star Sensor ◽  
Spherical Lens ◽  
Entrance Pupil ◽  
Secondary Mirror ◽  
Entrance Pupil Diameter

The optical system is one of the core components for star sensors, whose imaging quality directly influences the performance of star sensors for star detection, thereby determining the attitude control accuracy of spacecrafts. Here, we report a new type of optical system with a catadioptric structure and a large entrance pupil diameter for a 15-magnitude star sensor. It consists of an improved Cassegrain system (R-C system), an aperture correction spherical lens group and a field of view correction spherical lens group. By embedding the secondary mirror of the R-C system into the output surface of the negative spherical lens of the aperture correction spherical lens group, the blocking of incident light is eliminated from the secondary mirror holder. After the structure optimization, the catadioptric optical system (COS) had a spectral range of 450 nm–950 nm, an entrance pupil diameter of 250 mm, a half-diagonal field of view of 1.4° and a focal length of 390 mm. By using theoretical calculations and experimental measurements, it was verified that the COS, with the ability to correct astigmatism, lateral color and distortion, can fulfill the detection of 15-magnitude dark stars.

Optical system design of star sensor with long focal length and athermalization

2020 ◽  
Vol 49 (9) ◽  
pp. 20200061-20200061
Author(s):  
伍雁雄 Yanxiong Wu ◽  
乔健 Jian Qiao ◽  
王丽萍 Liping Wang
Keyword(s):  
System Design ◽  
Optical System ◽  
Focal Length ◽  
Star Sensor ◽  
Optical System Design

Design of infrared optical system with super-long focal length and dual field-of-view

2014 ◽  
Vol 7 (4) ◽  
pp. 631-637
Author(s):  
白玉琢 BAI Yu-zhuo ◽  
木锐 MU Rui ◽  
马琳 MA Lin ◽  
贾钰超 JIA Yu-chao ◽  
普群雁 PU Qun-yan ◽  
...  
Keyword(s):  
Optical System ◽  
Focal Length ◽  
Field Of View

Diffraction ring pattern at the focal plane of a spherical lens – axicon doublet

1976 ◽  
Vol 54 (17) ◽  
pp. 1774-1780 ◽  
Author(s):  
Pierre-André Bélanger ◽  
Marc Rioux
Keyword(s):  
Plane Wave ◽  
Laser Beam ◽  
Optical System ◽  
Focal Plane ◽  
Focal Length ◽  
Spherical Lens ◽  
Diffraction Ring ◽  
Fresnel Integral ◽  
Drill Holes

A spherical lens and an axicon are combined to form an optical system producing a ring-shaped focalization pattern. The diameter of the ring in the focal plane depends on the angle of the axicon, on its dielectric index, and on the focal length of the spherical lens. The diffractional analysis of the lens–axicon combination, when illuminated by a plane wave, is presented. In particular, we show that, when the aperture is large, the Kirchhoff–Fresnel integral can be reduced to a known function. A close examination of the function reveals that the diffractional width of the ring is equal to approximately twice the width of the Airy pattern of the lens alone. This type of focalization is well suited for a system where a laser beam is used to drill holes.

Optical Design of Very Large Four-Mirror Systems

2007 ◽  
Vol 364-366 ◽  
pp. 1231-1236 ◽  
Author(s):  
Li Rong Zhu ◽  
Wei Min Shen
Keyword(s):  
Focal Length ◽  
Optical Design ◽  
Diffraction Limit ◽  
Field Of View ◽  
Initial Structure ◽  
Entrance Pupil ◽  
Primary Mirror ◽  
Imaging Quality ◽  
Large Aperture ◽  
Design Idea

Four-mirror systems with a very large aperture and a long focal length were investigated and designed. Their design idea is given. Through the derivation of primary aberration formula, the aberration properties were analyzed and discussed, and the method to determine its initial structure is reported. As examples, two four-mirror systems with spherical and parabolic primary mirror, 100m focal length, and 10m entrance pupil were optimally designed. Their imaging quality approaches diffraction limit within field of view of 0.4 and 0.5 degrees respectively.

Optical system design of star sensor with long focal length and athermalization

2020 ◽  
Vol 49 (9) ◽  
pp. 20200061-20200061
Author(s):  
伍雁雄 Yanxiong Wu ◽  
乔健 Jian Qiao ◽  
王丽萍 Liping Wang
Keyword(s):  
System Design ◽  
Optical System ◽  
Focal Length ◽  
Star Sensor ◽  
Optical System Design

Optical System Design of Large Entrance Pupil Catadioptric Star Sensor

2014 ◽  
Vol 41 (7) ◽  
pp. 0716002
Author(s):  
吕博 Lü Bo ◽  
刘伟奇 Liu Weiqi ◽  
张大亮 Zhang Daliang ◽  
姜珊 Jiang Shan ◽  
康玉思 Kang Yusi ◽  
...  
Keyword(s):  
System Design ◽  
Optical System ◽  
Star Sensor ◽  
Entrance Pupil ◽  
Optical System Design

Analysis on Resolution Enhancement by Optical Pupil Apodization in a Laser Scanning Printing System

2016 ◽  
Author(s):  
Wan-chin Kim ◽  
Sang-Koo Han ◽  
Sung-Dae Kim
Keyword(s):  
Optical System ◽  
Laser Scanning ◽  
Focal Length ◽  
Resolution Enhancement ◽  
Focal Depth ◽  
Optical Resolution ◽  
Spot Size ◽  
Experimental Result ◽  
Entrance Pupil ◽  
High Degree

Apodization of amplitude and phase at the entrance pupil of an optical system is able to have advantages on optical resolution and focal depth. As an optical system for the electro-photography continuously requires highly resolved dot image and extended focal length to obtain more delicate expression with adequate production stability. Advantages from apodization technique can improve system performance and supply high degree of reliability of the optical system. In this study, theoretical apodization characteristics in a laser scanning optical system for electro-photography is firstly analyzed in the aspects of enhancement of optical resolution and focal depth with the proposed method of apodization. In addition, fundamental experimental result on measurement of beam spot size is reported to support theoretical results.

scholarly journals A Novel Focal Length Measurement Method for Center-Obstructed Omni-Directional Reflective Optical Systems

2019 ◽  
Vol 9 (11) ◽  
pp. 2350 ◽  
Author(s):  
Hojong Choi ◽  
Joo-Youn Jo ◽  
Jae-Myung Ryu
Keyword(s):  
Optical System ◽  
Measurement Method ◽  
Focal Length ◽  
Tolerance Analysis ◽  
Field Of View ◽  
Optical Systems ◽  
Wide Field ◽  
Surveillance Camera ◽  
Length Measurements ◽  
Design Software

An omni-directional optical system can be used as a surveillance camera owing to its wide field angle. In cases in which a system is designed with a central screen obscuring structure to increase the resolution of the off-axis field, however, the conventional methods cannot be used to measure the effective focal length (EFL). We assumed the actual and theoretical distortion values of the fabricated optical system to be the same and determined the system’s EFL by finding the minimum deviation point of the measured and theoretical distortions. The feasibility of the determined EFL was verified through a tolerance analysis of the system. For these precise measurements we also analyzed the sources of error. To verify our proposed measurement method, we measured the focal length of a center-obstructed omni-directional reflective optical system with an 80–135° field of view (FOV). The EFL from the measurement was 0.3739 mm and was only approximately 11 µm different from the EFL calculated using the design software. Thus, the reliability of focal length measurements in omni-directional optical systems was improved.

scholarly journals Geometric model of image formation in Scheimpflug cameras

2016 ◽  
Author(s):  
Indranil Sinharoy ◽  
Prasanna Rangarajan ◽  
Marc P. Christensen
Keyword(s):  
Pupil Diameter ◽  
Geometric Model ◽  
Image Formation ◽  
Imaging Systems ◽  
Depth Of Field ◽  
Entrance Pupil ◽  
Scheimpflug Imaging ◽  
The Relationship ◽  
Special Case ◽  
Entrance Pupil Diameter

We present a geometric model of image formation in Scheimpflug cameras that is most general. Scheimpflug imaging is commonly used is scientific and medical imaging either to increase the depth of field of the imager or to focus on tilted object surfaces. Existing Scheimpflug imaging models do not take into account the effect of pupil magnification (i.e. the ratio of the exit pupil diameter to the entrance pupil diameter), which we have found to affect the type of distortions experienced by the image-field upon lens rotations. In this work, we have also derived the relationship between the object, lens and sensor planes in Scheimpflug configuration, which is very similar in form with the standard Gaussian imaging equation, but applicable for imaging systems in which the lens plane and the sensor plane are arbitrarily oriented with respect to each other. Since the conventional rigid camera, in which the sensor and lens planes are constrained to be parallel to each other, is a special case of the Scheimpflug camera, our model also applies to imaging with conventional cameras.

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