WFI Read Noise and Gain Performance |
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Only one speed (FAST) is available.Read noises and gains were determined using the MSCFINDGAIN itask in IRAF for 2 sets of usable data on the night of 01 and 02 Feb. 2001 Focal plane was operated at 183K for these tests.
Results of 2 observations over 2 nights - Unbinned. CCD Section=[800:1000,1400:2000]
CCD Gain (e/adu) ReadNoise (e) 1 1.42,1.42 5.6,6.9 2 1.68,1.68 4.9,5.3 3 1.92,1.93 4.2,5.1 4 1.65,1.64 5.3,5.6 5 1.98,2.02 4.1,5.6 6 1.66,1.71 5.0,5.9 7 1.82,1.85 3.4,5.1 8 1.69,1.76 3.7,6.9
Examination of the bias levels in 16 frames taken over 3 nights show that bias levels fluctutate up and down by +-2adu on all timescales - between subsequent exposures, over hours, and between nights. Overscan subtraction is important.
Only one speed (FAST) is available.Read noises and gains were determined using the MSCFINDGAIN itask in IRAF for 2 sets of usable data on the nights 25 dec, and 26dec. Focal plane was operated at 183K for these tests.
Results of 2 observations over 2 nights - Unbinned. CCD Section=[800:1000,1400:2000]
CCD Gain (e/adu) ReadNoise (e) 1 1.45,1.46 5.2,5.2 2 1.70,1.72 5.9,13.5? 3 1.94,1.97 5.7,6.7 4 1.73,1.72 4.9,4.9 5 2.00,2.04 4.7,4.6 6 1.67,1.67 4.7,4.5 7 1.88,1.88 4.2,3.9 8 1.68,1.71 4.0,4.6
Examination of the bias levels in 16 frames taken over 3 nights show that bias levels fluctutate up and down by +-2adu on all timescales - between subsequent exposures, over hours, and between nights. Overscan subtraction is important.
Only one speed (FAST) is available.Read noises and gains were determined using the MSCFINDGAIN itask in IRAF for 8 sets of usable data on the nights 23aug, 24aug and 25aug. On 21aug, 22aug and 23aug changes were made to CCD parameters. The gains and read-noises reported here only apply to times after these were finalised on 23aug.
Results of 6 observations over 3 nights - Unbinned. CCD Section=[800:1000,1400:2000]
CCD Gain (e/adu) ReadNoise (e) 1 1.41+-0.01 5.6+-0.6 2 1.63+-0.04 4.3+-0.4 3 1.89+-0.02 4.5+-0.4 4 1.63+-0.08 5.7+-1.3 5 1.98+-0.01 4.4+-0.2 6 1.56+-0.05 4.4+-0.2 7 1.79+-0.01 3.4+-0.4 8 1.66+-0.02 3.9+-0.3
Results of 1 observations on 1 nights - Binned x 2. CCD Section=[300:600,900:1200]
CCD Gain (e/adu) ReadNoise (e) 1 1.38 5.4 2 1.55 3.7 3 1.67 14.9 4 - - 5 1.86 4.2 6 1.63 5.3 7 1.73 5.0 8 1.61 3.9
Results of 1 observations on 1 nights - Binned x 3. CCD Section=[250:400,600:800]Except for a few cases where the binned calculation failed, the behaviour when binned seems to be the same as for when unbinned (which is expected). The unbinned behaviour seems stable.
CCD Gain (e/adu) ReadNoise (e) 1 1.44 6.8 2 1.47 3.8 3 1.80 4.4 4 1.60 9.3 5 1.79 4.3 6 1.54 5.7 7 1.73 6.8 8 1.59 4.0
Useful Links and other PFU/WFI Resources
- AAO Wide Field Imager (WFI) and Prime Focus Upgrade (PFU) page.
- WFI and PFU Commissioning and Performance Status.
- RSAA WFI Page
- RSAA WFI Workshop Page (workshop was held Oct 14-15 1999)
- WFI Survey Page including draft proposal resulting from the "Science with the WFI" Workshop.
- RSAA WFI Project page (Project team access only)
- IRIS2 Page
This page maintained by Chris Tinney (cgt@aaoepp.aao.gov.au)