AMPLIST
cosmologist wrote on Mar 30, 2009
Hi,
Does anyone know what AMPLIST is a header of an image stands for. It says : readout order y,x , but I still don't understand what that is. :shock:
Thanks
Mike Fitzpatrick wrote on Mar 30, 2009
See "cl> help quadformat" for details.
-Mike
-Mike
cosmologist wrote on Mar 30, 2009
Thanks,
It makes more sense now, It says it is the number of regions, does it mean the number of Data regions or both Data and Bias regions?
It makes more sense now, It says it is the number of regions, does it mean the number of Data regions or both Data and Bias regions?
Mike Fitzpatrick wrote on Mar 30, 2009
In general, a 'region' will contain both data and bias pixels. The number of regions is usually the number of amplifiers used to readout the data. This will also normally correspond to the number of extension in a MEF file. [Note I said normally, we're aware of formats (being considered if not yet readily available) where e.g. two amplifiers will be repacked into a single extension covering the whole CCD, but iraf won't handle these properly because of keyword conflicts.]
-Mike
-Mike
cosmologist wrote on Mar 30, 2009
Thanks for the clarification, so AMPLIST is basically the number of amplifiers, right? :idea:
Mike Fitzpatrick wrote on Mar 30, 2009
More correctly, the number of items in AMPLIST is the number of amplifiers used to readout the data. The actual labels are somewhat peculiar to the detector (e.g. the CTIO mosaic has labels "11 12 21 22" and not "1 2 3 4" because the first amplifier used to readout is identified as '11'). That label value is then appended to the ASEC, DSEC etc keywords to specify the pixel region.
-Mike
-Mike
cosmologist wrote on Mar 30, 2009
oh, so an AMPLIST of 11 for CTIO means 1 amplifier, 12 meqans 2 amplifiers, 21 means 3 and 22 means 4? :roll:
Mike Fitzpatrick wrote on Mar 30, 2009
No. The '11' is just the name. Consider
AMPLIST = "fred bob jane jill"
Four names means four amplifiers. So, AMPLIST="11" means 1 amplifier, AMPLIST="11 12" means two, and so on.
AMPLIST = "fred bob jane jill"
Four names means four amplifiers. So, AMPLIST="11" means 1 amplifier, AMPLIST="11 12" means two, and so on.
cosmologist wrote on Mar 30, 2009
Oh, thank you so much, it makes perfect sense to me now :D
Last post on Mar 30, 2009