Some considerations about structure of off-axis segments in stitching paraboloidal mirror

Gao Bilie

doi:10.1117/12.674092

30 May 2006 Some considerations about structure of off-axis segments in stitching paraboloidal mirror

Gao Bilie

Proceedings Volume 6148, 2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes; 61480H (2006) https://doi.org/10.1117/12.674092
Event: 2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies, 2005, Xian, China

Abstract

It is total different about structure of segment in stitching paraboloidal mirror and stitching spherical mirror or flat. Because of cuvature of the spherical mirror or flat is identical, even if in different points and different directions, so its surface appearance and external dimensions of all segments are identical too. But in paraboloidal mirror, its curvature radius is lengthening gradually, when the point deviates from apex to outer zone, even if in same point, its curvature is also different in different directions. When stitching all segments to an entire paraboloidal mirror, in order to make each edge curves of neighbouring segments keeping coincidence, all off-axis segments aren't regular hexagon, its external dimensions have slight variations. According to Dr. H. Martin's stitching pattern, if the maximum dimension of subsegment is 0.9M, the curvature radius of apex of paraboloid is 2.88M (the focal ratio of the entire paraboloidal mirror is near F/0.6), the author calculates the external dimensions of off-axis segment, its nearest optimum paraboloid, its nearest optimum sphere. On the other hand, the author analyzes the advantages and disadvantages about selecting which axis as rotative axis of off-axis segment under removal proceeding, for example selecting its normal line of center point of segment or its perpendicular bisector of segment in meridional plane. According to these analyses and calculations, this paper gives some suggestions and several sets of data about structure of off-axis segments. All these are just a base for further research in stitching paraboloidal mirror.

Citation Download Citation

Gao Bilie "Some considerations about structure of off-axis segments in stitching paraboloidal mirror", Proc. SPIE 6148, 2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, 61480H (30 May 2006); https://doi.org/10.1117/12.674092

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available