| About ROSAT |
ROSAT Home Page | ROSAT Images |
|---|
The Image Display, or North/South (NS), system is a cartesian frame
( 
) optimised for use by image display S/W.
By convention, astronomical images are usually displayed in the
same sense as one would see from the Earth (i.e., North to the top,
East to the left).
However, image display devices usually display images from
top-to-bottom and from left-to-right.
Thus the transformation from the relative coordinate system
( 
;
Sect. 2.5.2)
to the NS system is
(Fig. 2.7):
(the 
-axis is aligned with the nominal pointing direction
of the S/C, as is the case for the 
-axis).