QC PLOTS
	CURRENT	HISTORY
median level (master)
read-out noise (master)
read-out noise (raw)
structure in X (raw)
structure in Y (raw)
QC1 uves_bias database (advanced users): browse | plot
Click on CURRENT to see the last trending (Health Check).    Click on HISTORY to see the historical evolution of the trending.

This tutorial provides information for the BIAS Health Check trending. It is based on the measurement of QC1 parameters of BIAS calibration data obtained with dedicated Health Check OBs executed daily. These OBs obtain four sets of BIAS data, 2 sets in BLUE mode and 2 sets in RED mode, each set comprising 5 RAW frames. The 2 sets in each mode are acquired in the two main CCD ReadOut modes; 225kHz, low gain, 1x1 binning amd 50kHz, high gain, 2x2 binning. These data thus give detailed charateristics for all THREE UVES CCDs, one BLUE and two RED (UPPER and LOWER). Trending is provided for:

• Median level
• Readout Noise in the MASTER product
• Readout Noise in the first RAW frame
• Structure in the X-direction
• Structure in the Y-direction

QC1 parameters

• median value of master bias (QC1 database table uves_bias, column median_master, product keyword PRO.DATAMED)
  Exact median of the pixel values in the frame. All pixels are taken into account.
• RON value of master bias (QC1 database table uves_bias, column sigma_master, product keyword QC.OUTi.RON.MASTER)
  Read noise in ADU
• RON value of first raw frame (QC1 database table uves_bias, column sigma_raw, product keyword QC.OUTi.RON.RAW)
  Read noise in ADU
• structure in X direction (QC1 database table uves_bias, column struct_row, product keyword QC.OUTi.STRUCTX)
  Evidence of any possible structure in bias. To have more details on a bias image without saving the full image we collapse it along X or Y and compute the standard deviation of the corresponding point distribution. This is the STRUCTX/Y. A large or suddenly changed value of the structure is indication of some problem on the axis ortogonal to the direction of collapsation.
• structure in Y direction (QC1 database table uves_bias, column struct_col, product keyword QC.OUTi.STRUCTY)
  Evidence of any possible structure in bias. To have more details on a bias image without saving the full image we collapse it along X or Y and compute the standard deviation of the corresponding point distribution. This is the STRUCTX/Y. A large or suddenly changed value of the structure is indication of some problem on the axis ortogonal to the direction of collapsation.

A FULL history trending plot of the BIAS median levels is available here.
Other significant events during the instrument's lifetime:

• 2009-06: The RED UPPER CCD was exchanged.