CCD Orientations on the Sky

Pictured below are the orientations of various CCDs. Be aware that the (1,1) cornor of the CCD images are displayed in the upper-left corner in CCDAuto, but they're displayed in the lower-left corner when using DS9 or ximtool. Note that if you want to move a star to a different position on a CCD (e.g., to the East on the CCD) then you need to move the telescope in the opposite direction (e.g., West).

ST9 Imaging CCD + AO9:
___________________________________________________________
|   (1,1)                                                                                                           |
|                                     NORTH                                                                   |
|                                                                                                                      |
|                                           ^                                                                         |
|                                            |                                                                         |
|                                            |                                                                         |
|          EAST        <-----------                                                                         |
|                                                                                                                      |
|                                                                                                                      |
|                                                                                                  (512, 512)   |
|___________________________________________________________|

That is the orientation on the sky when the ST9 CCD's flat edge is downward and the rounded edge is upward relative to the 24" telescope. Keep the CCD in this orientation and do not rotate it. The pixel scale for the ST9 Science CCD is 0.809"/pix and the field of view is 6.9' x 6.9'. The ST9 Tracking CCD is located to the South of the Science CCD and its FOV is 2.6' x 2.2'.

ST6 CCD on the Finder/Guider Telescope:
_______________________________________________________________________
|   (1,1)                                                                                                                                 |
|                                                              NORTH                                                                |
|                                                                                                                                            |
|                                                                 ^                                                                         |
|                                                                  |                                                                         |
|                                                                  |                                                                         |
|                                                                  |                                                                         |
|                               EAST      <--------------                                                                         |
|                                                                                                                                            |
|                                                                                                                                            |
|                                                                                                                        (375, 242)   |
|______________________________________________________________________|

Note that the East-West direction of the ST6 CCD is flipped relative to the ST9 CCD's field of view. This CCD has rectangular shaped pixels so that the pixel scale in the x direction is 4.00"/pix and in the y direction is 4.75"/pix. The field of view is 25.0' x 19.2'.

Spectrograph Slit Viewing CCD
___________________________________
|                                                                     |
|                                                                     |
|                                                                     |
|        EAST    <--------  |                                | 
|                                     |                                |
|                                     |                                |  
|                                    V                               |
|                                                                      |
|                               NORTH                         |
|                                                                      |
|___________________________________|

The field of view is approximately 2' x 2'.

Last updated June 22, 2007