ITEM            structure
ITEM_TITLE      Structure
ITEM_ANAME      struct

	      <p>The GIRAFFE BIAS frames contain some structure which is monitored here. </p>

TITLE		QC1 parameters

TABLE_NAME	qc1
TABLE_TYPE	QC1_TABLE
TABLE_ROW1	QC.OUT1.STRUCT.X SEP giraffe_bias..struct_row	
TABLE_ROW2	QC.OUT1.STRUCT.Y SEP giraffe_bias..struct_col

TITLE		Trending

	      <p>Box <b>4</b> and <b>5</b> of the <a href="/qc/GIRAFFE/reports/HEALTH/trend_report_BIAS_HC.html">trending
	            plot</a> show the structure of the BIAS, derived from collapses
	      of columns (structure in X direction, left) and rows  (Y direction, right). </p>

TABLE_NAME	trending1
TABLE_TYPE	FIGURE_1
TABLE_WIDTH	80%
TABLE_IMG1	"../img/trend_bias_box4.gif" border="1"
TABLE_CAP1	<b>Structure plots</b>. The structure in X direction is derived
TABLE_CAP1	in the master bias, collapsed along the rows (box 4). The
TABLE_CAP1	structure in Y is obtained along the columns (box 5). The collapses are shown
TABLE_CAP1	below.

TABLE_NAME	trending2
TABLE_TYPE	FIGURE_1
TABLE_WIDTH	80%
TABLE_IMG1	"../img/bias_struct.gif" width="176" height="355" border="1" align="top"
TABLE_CAP1	           <b>Collapsed master bias</b>. 
TABLE_CAP1	           While     the master bias (both for the old and the new CCD) has virtually no structure
TABLE_CAP1	                in X direction (along the rows), it is quite structured in Y direction, along the
TABLE_CAP1	                columns. <p>
TABLE_CAP1	<br> <br> <br><br> <br> <br>  <br> <br>
TABLE_CAP1	            <p><i>Old CCD, Y direction</i>: Roughly the first 1000 rows increase from a level
TABLE_CAP1	                about 4 ADU below average to the average level. The step is due to the bad
TABLE_CAP1	                columns around column 420 starting at about row 1460.</p>

TABLE_NAME	trending3
TABLE_TYPE	FIGURE_1
TABLE_WIDTH	80%
TABLE_IMG1	"../img/bias_struc_new.png" width="180" height="353" border="1" align="top"
TABLE_CAP1	<b>New CCD (normal read mode)</b>
TABLE_CAP1	<br> <br> <br> <br> <br> <br> <br> <br> <br> <br>  <br> <br>
TABLE_CAP1	<i>Y direction</i>: the increase is much smoother
TABLE_CAP1	                and has an amplitude of less than 2 ADU. There is no bad column. 

TABLE_NAME	trending4
TABLE_TYPE	FIGURE_1
TABLE_WIDTH	80%
TABLE_IMG1	"../img/bias_struct_fast.gif" width="175" height="354" border="1"
TABLE_CAP1	<b>New CCD, fast read mode</b> 
TABLE_CAP1      <br> <br> <br> <br> <br> <br> <br> <br> <br> <br>  <br> <br>
TABLE_CAP1 	<i>Y direction</i>: structure looks very similar to the normal read mode.
TABLE_END

TITLE		History
		Both structure parameters are very stable with time.

TITLE		Scoring&thresholds
		Both structure parameters are scored, with fixed thresholds set such as to be insensitive to normal fluctuations. A red score indicates
		a real issue with the detector. There are no reference values available.

TITLE		Algorithm
The master_bias is collapsed in X or Y direction, the rms of the result frame is measured.