Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8133364 | Chinese Astronomy and Astrophysics | 2017 | 13 Pages |
Abstract
Limited by the working temperature of the test equipment, most of high-precision surface figure measurement techniques cannot be put into application under a cryogenic environment. This paper reports the first attempt to measure the surface figure of a high-precision terahertz reflector panel under low temperatures based on photogrammetry. The measurement employs a high-resolution industrial camera sitting on the automatic testing platform which enables photos been taken in an automatic fashion inside a climate chamber. A repeatable accuracy of 2.1 μm (rms) is achieved under the cryogenic environment. Furthermore, the surface figure measured by a three-coordinate measuring machine under the room temperature is used to calibrate the thickness differences of the targets. By this technique, the surface figure of an aluminum prototype panel of the 5 meter Dome A Terahertz Telescope (DATE5) is measured from room temperature down to â55°C to obtain the rule of variation of surface deformation of the panel under low temperatures.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Astronomy and Astrophysics
Authors
Lou Zheng, Qian Yuan, Fan Sheng-hong, Liu Chang-ru, Wang Hai-ren, Zuo Ying-xi, Cheng Jin-quan, Yang Ji,