O CCD Frames Bias frame Dark frame Flat-Field Bad pixel frame table Overscan region(有些cCD没有)
CCD Frames Bias frame Dark frame Flat-Field Bad pixel frame（table） Overscan region （有些CCD没有）
◎ BIAS Frames A bias current is routinely applied to CCD detectors to ensure that, as near as possible they are operating in a linear manner. But it also include some structure from readout BIAS Frame is dark frame with exposure of0 sec BIAS,是零秒暗场是CCD的本底值 (含读出的附加电压值)
BIAS Frames A bias current is routinely applied to CCD detectors to ensure that, as near as possible they are operating in a linear manner. But it also include some structure from readout. BIAS Frame is dark frame with exposure of 0 sec BIAS，是零秒暗场是 CCD的本底值 （含读出的附加电压值）
冒 Take Image
NOAO/IRAF Y2. 12.2a-3XPORT wug nhong bao ac cn Tue 23: 10: 55 12-Jul-2D05 Average of lines 548 to 1547 of d10olc biaB日s 1500 1000 500 500 1090 ⊥500 2000
O DARK Frames Dark current need to considered during a long exposure time But, at most cases, it can be neglected
DARK Frames Dark current need to considered during a long exposure time. But, at most cases, it can be neglected