Gemini world coordinates

Patrick T. Wallace

doi:10.1117/12.308826

26 May 1998 Gemini world coordinates

Patrick T. Wallace

Author Affiliations +

Proceedings Volume 3351, Telescope Control Systems III; (1998) https://doi.org/10.1117/12.308826
Event: Astronomical Telescopes and Instrumentation, 1998, Kona, HI, United States

Abstract

The Gemini World Coordinate Systems (WCS) facilities support various types of astrometric coordinates as well as instrument-specific quantities such as wavelengths or times. The astrometric facilities are based on the principle that, for sky-imaging applications, users are concerned only with (i) positions in the focal plane and (ii) celestial coordinates. All intermediate calculations, for example involving the position of the tip/tilt secondary mirror, the orientation of the instrument rotator, the selection of focal station, differential refraction and atmospheric dispersion, and field rotation effects caused by misalignments in the telescope mount, are encapsulated in the WCS transformation. We have implemented a library of C functions which support Gemini astrometric world coordinates. Most of them can be run off-line, and are applicable to other telescopes. More general WCS problems, involving data coordinates as well as astrometry, are treated by breaking the telescope, instrument and detector into a set of 'agents' each of which manages its own local transformations. The individual transformations can then be combined to provide the end-to-end transformations needed by data display and analysis facilities.

Citation Download Citation

Patrick T. Wallace "Gemini world coordinates", Proc. SPIE 3351, Telescope Control Systems III, (26 May 1998); https://doi.org/10.1117/12.308826

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