Calibration Access and Data Handbook

Description

Provides the list of bad (hot/dead/flickering) CCD pixels, either uploaded on-board or characterized on-ground.

The CCF contains the following tables:

BADPIX

Accessed by :

• CAL_getBadPixelMap():
• CAL_getBadPixelList(): Provides the list of bad (hot/dead/flickering) CCD pixels.

Attributes:

None.

Columns:

CCD_ID :

the CCD index number (1-7)

NODE_ID :

node name (either 0 or 1 for MOS)

RAWX :

PIXCOORD1, start of bad pixel region in RAWX

RAWY :

PIXCOORD2, start of bad pixel region in RAWY

YLENGTH :

length of bad column ( ${\tt YLENGTH}=1$ indicates a single bad pixel)

DESCRIPTION :

type of the bad pixel listed (see below)

MODE_N/A :

mode for which bad pixels are not applicable

Note that RAWX & RAWY will be in absolute coordinates on the CCD chip, and are thus independent of any windowing information.

A bad CCD pixel can be (value of DESCRIPTION):

• dead: no signal is ever detected in this pixel. All pixels that are parallel transferred through a dead pixel are dead as well. (type value equals 'd' if uplinked, equals 'D' if stored in CCF only)
• hot: a pixel that contains a signal almost at every readout of the CCD. The charge content of such a pixel is nearly constant, and is dependent on the CCD bias and readout parameters. (type value equals 'h' if uplinked, equals 'H' if stored in CCF only)
• flickering: the characteristics of flickering pixels depend on the CCD bias and readout parameters, as well as on the average charge that is transferred through them during readout. (type value equals 'f' if uplinked, equals 'F' if stored in CCF only)