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Projection - Sky projection description

Description:
This attribute provides a place to store a description of the type of sky projection used when a SkyFrame is attached to a 2-dimensional object, such as an image or plotting surface. For example, typical values might be "orthographic", "Hammer-Aitoff" or "cylindrical equal area".

The Projection value is purely descriptive and does not affect the celestial coordinate system represented by the SkyFrame in any way. If it is set to a non-blank string, the description provided may be used when forming the default value for the SkyFrame's Title attribute (so that typically it will appear in graphical output, for instance). The default value is an empty string.

Type:
String.
Class Applicability:
SkyFrame
All SkyFrames have this attribute.


next up previous 264
Next: RefCount - Count of active Object pointers
Up: AST Attribute Descriptions
Previous: ProjP(m) - FITS-WCS projection parameters

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 210
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council