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CCD Quality Control

The bias value, readout noise, gain, and in the linearity of the WFC CCDs are monitored by the Support Astronomers. During any D-nights, SAs, please run the QC tests and report the results to the WFC instrument specialist to update this table. Report any anomalous value to the Operations team via a Fault report.

The following table include measurements in binning 1x1, for both slow and fast readout modes. Similar values are obtained for binning 2x2 except for CCD2 where the noise is about 30 times higher. Thus, binning 2x2 mode could be used safely with the other three CCDs or a smaller window of the central CCD4.

Date
Readout
Speed
Bias (ADU)
Readout Noise (ADU)
Gain (e-/ADU)
CCD1
CCD2
CCD3
CCD4
CCD1
CCD2
CCD3
CCD4
CCD1
CCD2
CCD3
CCD4
NOMINAL
(2017-08-16)
slow 2106
2247
2271
2210
4.8
2.5
3.5
2.8
1.2
1.6
1.2
1.6
2006-10-31

1555
1503
1552
1571
2.9
4.3
4.9
3.3




2006-11-28

767
813
718
725
2.9
2.2
3.2
2.5
2.6
3.2
2.5
3.1
2006-12-12

749
804
712
722
2.8
2.0
3.1
2.5
2.8
3.2
2.6
3.2
2006-12-24

729
793
712
724
3.0
2.2
3.1
2.4




2007-01-03

726
784
715
728
2.8
2.2
3.2
2.5




2007-01-04

723
790
711
724
2.8
2.0
3.0
2.3
2.8
3.2
2.5
3.1
2007-04-10

1944
1931
2016
1934
2.8
2.1
2.9
2.4
2.6
3.2
2.5
3.1
2007-05-10
fast
1917
1917
1976
1910
3.4
2.7
3.5
3.0
2.6
3.5
2.6
3.3
2007-05-10
slow
2218
2246
2288
2219
4.5
3.2
4.5
3.4
1.3
1.7
1.2
1.6
2007-05-17
fast
1917
1922
1976
1910
3.7
2.7
3.6
2.8
2.6
3.5
2.5
3.3
2007-05-17
slow
2218
2251
2290
2222
4.2
3.5
4.6
3.5
1.3
1.7
1.2
1.6
2007-06-07
fast
1908
1918
1987
1917








2007-07-14
fast
1896
1915
1960
1910
2.8
2.2
2.6
2.5
2.6
3.5
2.5
3.3
2007-07-16
slow
2220
2265
2292
2238
4.4
3.3
4.0
3.4
1.3
1.7
1.2
1.6
2007-11-07
fast
1897
1912
1965
1900
2.9
2.3
2.7
2.6




2007-11-07
slow
2206
2245
2281
2213
4.3
3.0
3.8
2.2
1.3
1.7
1.2
1.6
2008-01-16
fast
1894
1908
1960
1899
2.9
2.5
2.6
2.6
2.6
3.4
2.4
3.2
2008-01-16
slow
2208
2239
2280
2215
4.9
3.6
4.0
3.3
1.3
1.7
1.2
1.5
2008-01-22
fast
1893
1908
1960
1900
2.9
2.4
2.7
2.7
2.5
3.4
2.3
3.2
2008-01-22
slow
2210
2244
2281
2220
4.9
3.9
3.9
4.4
1.3
1.7
1.2
1.6
2008-11-26
slow




3.3
2.7
2.8
2.5




2011-06-17
slow
2059
2201
2204
2156
3.6
2.5
3.5
2.7
1.0
1.3
0.9
1.2
2011-06-17
fast
1838
1908
1949
1895
2.6
2.0
2.7
2.4
2.4
3.1
2.2
2.9
2011-07-03
slow
2072
2219
2216
2167
3.7
2.6
3.6
2.8
1.1
1.5
1.0
1.4
2011-07-03
fast
1853
1925
1959
1906
2.7
2.0
2.7
2.4
2.7
3.6
2.6
3.4
2011-09-10
slow
2072
2226
2217
2165
3.6
2.5
3.6
2.8
1.3
1.7
1.2
1.6
2011-09-10
fast
1851
1931
1959
1904
2.4
2.0
2.6
2.3
2.4
3.2
2.3
3.0
2011-11-11
slow
2046
2169
2221
2141
8.0
10.6
7.8
5.9
1.2
1.6
1.1
1.5
2011-11-11
fast
1821
1873
1953
1882
7.1
6.0
7.6
5.5
1.5
2.0
1.4
1.9
2012-09-29
slow
2107
2228
2242
2164
4.6
2.8
3.9
3.1
1.1
1.5
1.1
1.5
2012-09-29
fast
1906
1943
1986
1911
3.0
2.1
2.7
2.2
0.6
0.8
0.5
0.7
2012-11-05
slow
2117
2217
2288
2197
4.5
2.7
3.8
3.0
1.2
1.7
1.3
1.6
2012-11-05
fast
1912
1940
1982
1910
3.3
2.2
2.8
2.3
1.9
2.5
1.8
2.4
2013-02-01
slow
2060
2172
2217
2148
6.6
4.0
4.3
3.6
1.2
1.6
1.2
1.5
2013-02-01
fast
1881
1907
1977
1908
3.9
2.3
2.6
2.6
2.1
2.8
2.1
2.7
2013-04-05
slow
2092
2195
2231
2168
4.6
2.7
3.3
2.6




2013-04-05
fast
1897
1915
1977
1910
2.9
1.9
2.2
1.9




2013-06-03
slow
2103
2218
2239
2176
4.5
2.7
3.5
2.9
1.2
1.7
1.2
1.6
2013-06-03
fast
1906
1930
1981
1921
3.2
2.3
2.5
2.2
2.5
3.4
2.5
3.3
2013-10-15
slow
2087
2190
2255
2178
4.3
2.7
3.6
3.0
1.1
1.5
1.1
1.4
2013-10-15
fast
1908
1925
2014
1941
3.4
2.3
2.8
2.5
2.1
2.8
2.1
2.7
2013-11-27
slow
2103
2218
2239
2176
5.5
4.5
4.6
4.9
1.2
1.7
1.2
1.6
2013-11-27
fast
1906
1930
1981
1921
8.0
7.2
7.4
9.1
2.6
3.4
2.5
3.3
2014-02-20
slow
2070
2205
2264
2192
4.9
2.8
4.0
3.4
1.2
1.6
1.2
1.5
2014-02-20
fast
1896
1931
2019
1942
3.4
2.2
2.8
2.5
0.8
1.0
0.7
1.0
2014-03-18
slow
2083
2207
2252
2200
4.8
2.8
3.9
3.4
1.0
1.3
1.0
1.3
2014-03-18
fast
1906
1932
2016
1950
3.4
2.3
3.0
2.7
0.5
0.7
0.5
0.6
2014-06-23
slow
2073
2202
2256
2196
4.8
2.8
3.8
3.3
1.2
1.7
1.2
1.6
2014-06-23
fast
1902
1932
2010
1947
3.5
2.4
3.0
2.7
2.5
3.4
2.5
3.3
2014-07-28
slow
2088
2228
2270
2205
4.7
2.8
3.8
3.2
1.2
1.7
1.2
1.6
2014-07-28
fast
1903
1939
2016
1946
3.5
2.3
2.9
2.5
2.5
3.4
2.5
3.3
2014-10-13
slow
2093
2247
2285
2211
4.8
2.8
3.8
3.2
1.2
1.7
1.2
1.6
2014-11-02
slow
2071
2216
2293
2232
4.7
2.7
3.6
2.9
1.2
1.7
1.2
1.6
2014-11-02
fast
1936
1947
2040
1959
3.6
2.4
3.1
2.8
2.6
3.5
2.6
3.4
2014-11-19
slow
2116
2229
2284
2210
5.0
2.9
3.9
3.3
1.2
1.7
1.2
1.6
2014-11-19
fast
1932
1949
2035
1960
3.6
2.4
3.1
2.8
2.6
3.4
2.4
3.3
2014-12-15
slow
2124
2227
2292
2214
5.0
2.8
3.8
3.1
1.2
1.7
1.2
1.6
2014-12-15
fast
1942
1942
2043
1956
3.7
2.5
3.3
2.7
2.7
3.5
2.6
3.4
2015-01-14
slow
2135
2222
2313
2217
5.1
2.9
4.0
3.2
1.2
1.7
1.5
1.6
2015-01-14
fast
1942
1942
2043
1956
3.7
2.5
3.3
2.7
2.7
3.5
2.6
3.4
2015-01-28
slow
2080
2199
2230
2179
7.7
5.6
6.7
5.0
1.2
1.7
1.2
1.6
2015-01-28
fast
1895
1914
1978
1924
5.9
5.0
6.4
4.9
2.6
3.4
2.6
3.3
2015-08-04
slow
2129
2287
2304
2230
4.7
2.9
4.0
3.3
1.2
1.7
1.2
1.6
2015-08-04
fast
1929
1980
2038
1969
3.6
2.4
3.2
2.9
2.6
3.5
2.6
3.4
2015-10-13
slow
2140
2250
2279
2216
4.9
2.9
3.9
3.2
1.2
1.7
1.2
1.6
2015-10-13
fast
1941
1957
2023
1959
3.7
2.5
3.1
2.8
2.6
3.4
2.5
3.3
2016-02-02
slow
2108
2238
2277
2212
5.2
2.7
3.6
3.1
1.2
1.7
1.2
1.6
2016-02-02
fast
1934
1961
2033
1966
3.3
2.0
3.1
2.3
2.6
3.4
2.3
3.4
2016-03-10
slow
2101
2235
2266
2207
4.9
2.7
3.6
3.1
1.2
1.7
1.5
1.6
2016-03-10
fast
1928
1957
2031
1962
3.2
1.9
2.3
2.2
2.6
3.5
2.5
3.3
2016-10-16
slow
2114
2212
2282
2211
5.1
2.6
3.4
2.9
1.2
1.7
1.2
1.6
2016-10-13
fast
1930
1956
2028
1964
3.6
2.2
2.6
2.3
2.5
3.4
2.5
3.2
2016-11-22
slow
2096
2205
2256
2200
4.6
2.5
3.3
2.7
1.2
1.7
1.2
1.6
2016-11-22
fast
1908
1929
2010
1947
3.2
1.9
2.2
2.0
2.6
3.4
2.6
3.3
2017-02-10
slow
2080
2203
2253
2193
4.6
2.5
3.4
2.9
1.2
1.7
1.2
1.6
2017-02-10
fast
1907
1932
2016
1949
3.2
1.9
2.3
2.2
2.5
3.4
2.6
3.3
2017-07-06
slow
2096
2222
2250
2198
4.3
2.4
3.3
2.7
1.3
1.7
1.3
1.7
2017-07-06
fast
1911
1939
2008
1946
3.0
1.9
2.2
2.0
2.6
3.5
2.5
3.4
2017-08-16
slow
2106
2247
2271
2210
4.8
2.5
3.5
2.8
1.2
1.6
1.2
1.6
2017-08-16
fast
1919
1951
2008
1948
4.0
2.0
2.5
2.6
2.5
3.4
2.5
3.2
Date
Readout
Speed
Bias (ADU)
Readout Noise (ADU)
Gain (e-/ADU)
CCD1
CCD2
CCD3
CCD4
CCD1
CCD2
CCD3
CCD4
CCD1
CCD2
CCD3
CCD4


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Contact:  (WFC Instrument Specialist)
Last modified: 17 August 2017
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