UKIRT
Show document only
UKIRT Home
Contact Info
OMP
UKIRT Staff wiki
Weather
Web Cameras
____________________

Survey Observing
Other Observing
Observing Tool Manual
Schedule
Applying For Time
Get UKIDSS Data
Get non-UKIDSS Data
Data Reduction
Acknowledge Us
Telescope
WFCAM
Cassegrain
Technical Reference
UKIRT Publications
Graphical Weather Server
EAO Safety Manual
UKIRT Waiver Form
TSS Priority Page
Array Latency

CGS4 Latency

It has come to our knowledge that the 256 x 256 InSb array in CGS4 suffers from small scale  latent images. This problem has only become noticeable since long integrations have become possible due to the small pixel sizes in use with the long focal length camera.

In general, the latency only affects long exposures of very faint sources after previously observing a bright source (e.g., a standard star). The level of latency varies, but is usually less than about 5 counts (30 electrons) above the general background level.

The simplest method to rid the array of the latent image is to ask your TSS to run manpeak to take a few short exposures without changing the apperture, once you are pointing at your faint source.

If your targets are bright enough to peakup on, then the above procedure is unnecessary. The process of peaking up will remove any latent image.

Contact: Tom Kerr. Updated: Tue Jan 25 11:09:02 HST 2005

Return to top ^