Detector Characteristics

Read Out Noise: Recent values (ADU)

Date \ Quadrant Lower Left Lower Right Upper Left Upper Right
May 13,  2005 2.239 2.113 2.117 2.092
Jul 28,  2010 2.224 2.084 2.107 2.071
May 22,  2011 2.226 2.091 2.104 2.083
May 8,  2012 2.258 2.115 2.133 2.089
Sept 28,  2012 2.217 2.078 2.104 2.072

Read-out Noise evolution since January 1998 (Last updated 2012-09-30).

Gain: Recent values (e-/ADU)

Date Gain
May 23, 2005 5.271
Jul 28, 2010 5.462
May 19, 2011 5.315
May 3, 2012 5.320
Sept 30, 2012 5.373
Gain evolution since August 1998 (Last updated 2012-09-30).

Non-Linearity: Recent values

Month Linearity
Sep 2003
 Less than 1.5% between 50 and 10000 ADUs
Jul 28, 2010
 Less than 0.5% between 50 and 10000 ADUs
For more info see the linearity page (Last updated 2012-09-30).

Bad Pixels: Recent values

Date   Dead pixels  Hot pixels  Noisy pixels  Total bad pixels
 Apr 2003*
 9120
 239
 3577
 9666
 Dec 2008*
 12760
 228
 749
 13490
 Jul 28, 2010
 11725
 261
 669
 12451
 May 13, 2012
 10722
 232
 301
 11122
 Oct 4, 2012
 14315
 312
 489
 14884

*The apparent increase in the number of bad pixels since April 2003 cannot fully be ascribed to a degradation of the array per se. The number of dead pixels strongly depends on the shape of the vignetted area of the array which has changed since Apr 2003. As the new bad pixel map is created independently of the one from Apr 2003, the chosen accuracy for identifying bad pixels also affects the number of dead, hot, and noisy pixels.

Some pixels fall into more than one category, i.e. hot and noisy, so the total bad pixels count is less than the sum of the three previous columns.

Go to the bad pixel images (last updated 2012-05-13).