Development of an off-axis TMA telescope for coastal water remote sensing
A proto-model of an off-axis reflective fore-optics in a new hyperspectral sensor onboard a small unmanned aerial vehicle (UAV) is developed for low-altitude coastal remote sensing. In spite of the substantial advantages of off-axis optics over refractive or on-axis reflective optics, it is difficul...
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Published in | International journal of precision engineering and manufacturing Vol. 17; no. 5; pp. 685 - 689 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Seoul
Korean Society for Precision Engineering
01.05.2016
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Subjects | |
Online Access | Get full text |
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Summary: | A proto-model of an off-axis reflective fore-optics in a new hyperspectral sensor onboard a small unmanned aerial vehicle (UAV) is developed for low-altitude coastal remote sensing. In spite of the substantial advantages of off-axis optics over refractive or on-axis reflective optics, it is difficult to fabricate and align the mirrors in off-axis systems because of their asymmetric configurations. The fore-optics is designed by Korea Institute of Ocean Science & Technology (KIOST) as a three-mirror system including aspheric primary and secondary mirrors, with an entrance pupil diameter of 70 mm and F-ratio of 5.0. The off-axis mirror is fabricated by a single point diamond turning machine (SPDTM) with a form accuracy of 89.3 nm (RMS) and surface roughness of 7.2 nm (Ra). Coarse alignment of this three-mirror off-axis optical system is accomplished by using a designated base plate and a coordinate measuring machine. The optical performance is tested using the point spread function of the returned collimated beam of a Fizeau interferometer. |
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ISSN: | 2234-7593 2005-4602 |
DOI: | 10.1007/s12541-016-0084-y |