The center of curvature optical assembly for the JWST primary mirror cryogenic optical test

2010 ◽  
Author(s):  
Conrad Wells ◽  
Gene Olczak ◽  
Cormic Merle ◽  
Tom Dey ◽  
Mark Waldman ◽  
...  
Keyword(s):  
Primary Mirror ◽  
Optical Test

Optical test for the primary mirror of a space telescope using a CGH null lens

2006 ◽  
Author(s):  
Jae Bong Song ◽  
Yun Woo Lee ◽  
Hoi Youn Lee ◽  
Ho Soon Yang ◽  
In Won Lee
Keyword(s):  
Space Telescope ◽  
Primary Mirror ◽  
Optical Test

Comparing optical test methods for a lightweight primary mirror of a space-borne Cassegrain telescope

2014 ◽  
Vol 25 (9) ◽  
pp. 094014 ◽  
Author(s):  
Wei-Cheng Lin ◽  
Shenq-Tsong Chang ◽  
Zong-Ru Yu ◽  
Yu-Chuan Lin ◽  
Cheng-Fong Ho ◽  
...  
Keyword(s):  
Test Methods ◽  
Primary Mirror ◽  
Optical Test ◽  
Cassegrain Telescope

scholarly journals Design of athermalized mounting structure for the sub-aperture primary mirror of a synthetic aperture telescope

2022 ◽  
Vol 14 (1) ◽  
pp. 168781402110670
Author(s):  
Yunfeng Li ◽  
Zongxuan Li ◽  
Qiang Yong ◽  
Tiancong Wang ◽  
Defu Zhang
Keyword(s):  
Temperature Rise ◽  
Simulation Analysis ◽  
Structural Parameters ◽  
Thermal Sensitivity ◽  
Synthetic Aperture ◽  
Axial Position ◽  
Range Analysis ◽  
Primary Mirror ◽  
Good Imaging ◽  
Optical Test

The imaging quality of the synthetic aperture system is sensitive to the positioning accuracy of the sub-aperture primary mirror. A novel flexible mounting structure of bimetallic material is proposed for the athermalization of the sub-aperture primary mirror of the Fizeau Synthetic Aperture Telescope – which is composed of seven sub-aperture. The axial position accuracy of the sub-aperture primary mirror must be less than 5 µm under 10°C temperature rise to meet the requirements of the optical system. Firstly, a single mounting unit is analyzed theoretically, and the initial parameters are determined. The conceptual design of the mounting structure is carried out by using initial parameters. The orthogonal optimization algorithm and range analysis are used to optimize the structural parameters. The finite element model of the flexible mounting structure is established and the coupled thermal-mechanical simulation analysis is performed. Then the thermal sensitivity test of the sub-aperture primary mirror mounting structure was carried out. Under the effect of a temperature rise of 10°C, the axial displacement of the sub-aperture primary mirror mounting surface is less than 3 µm. Finally, the synthetic aperture system is assembled, and the optical test verifies that the synthetic aperture system has good imaging capabilities.

The center of curvature optical assembly for the JWST primary mirror cryogenic optical test: optical verification

2010 ◽  
Author(s):  
Conrad Wells ◽  
Gene Olczak ◽  
Cormic Merle ◽  
Tom Dey ◽  
Mark Waldman ◽  
...  
Keyword(s):  
Primary Mirror ◽  
Optical Test

Thermal control of primary mirror of Space Solar Telescope

Optik ◽  
2021 ◽  
Vol 229 ◽  
pp. 166290
Author(s):  
Shuang Yang ◽  
Changshuai Du ◽  
Xianwei Yang ◽  
Chunlong Liu ◽  
Yan Xiong ◽  
...  
Keyword(s):  
Thermal Control ◽  
Solar Telescope ◽  
Primary Mirror ◽  
Space Solar Telescope

A method for tire wet grip performance evaluation based on grounding characteristics

2021 ◽  
pp. 095440702110158
Author(s):  
Chen Liang ◽  
Maoqing Shan ◽  
Guolin Wang ◽  
Daqian Zhu ◽  
Xingpeng Chen
Keyword(s):  
Pressure Distribution ◽  
Contact Area ◽  
Central Area ◽  
Principal Component ◽  
Area Ratio ◽  
Width Ratio ◽  
Characteristic Parameters ◽  
Radial Tire ◽  
Optical Test ◽  
Wet Grip

The wet grip performance of tire is one of the important performances affecting vehicle safety. The steering, acceleration, and braking of the vehicle are directly affected by the grounding characteristics between the radial tire and the ground. In order to study the influence of grounding characteristics of the tire on wet grip performance, ten 205/55R16 tires produced by different manufacturers were selected and tested. The grounding characteristics of the tires were tested using an optical test rig for tire grounding pressure distribution, considering inflation pressure distribution, load and wheel alignment. The tire-road contact area was subdivided into five parts, and 69 parameters were used to describe the grounding characteristics. A software was proposed to process the test results automatically, and 69 grounding characteristic parameters of each tire were obtained. Correlation analysis on tire wet grip performance and grounding characteristics was used for selecting the principal parameters. Finally, eight grounding characteristic parameters related to tire wet grip performance was obtained. Among them are five grounding characteristic parameters (central area rectangle ratio, central area width, internal shoulder length-to-width ratio, external and internal shoulder contact area ratio, external and internal shoulder impression area ratio) which have high correlation to tire wet grip performance, and three grounding characteristic parameters (external shoulder width, external shoulder length-to-width ratio, external and internal shoulder width ratio) which have low correlation to the wet grip performance of the tire. The principal component analysis method was used to analyze the highly correlated grounding characteristic parameters, and the regression equation for evaluating tire wet grip performance was fitted. The comparison of experimental and fitted values show that the errors are within 4%. The result demonstrates that, the method for evaluating wet grip performance of the radial tire through tire-road grounding characteristics was achieved.

Precise positioning of the test surface and screen in a coaxial software configurable optical test system

2020 ◽  
Vol 31 (4) ◽  
pp. 045010
Author(s):  
Mei Hui ◽  
Xinji Li ◽  
Ning Li ◽  
Ming Liu ◽  
Liquan Dong ◽  
...  
Keyword(s):  
Test System ◽  
Test Surface ◽  
Precise Positioning ◽  
Optical Test
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