% @(#)testc_ccd.hlq	1.1 (ESO-SDAG) 8/4/95 14:11:04
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1994 European Southern Observatory
%.IDENT      testc_ccd.hlq
%.AUTHOR     RHW, SDAG/ESO
%.KEYWORDS   MIDAS, ccd package, charge transfer, ccd testing
%.PURPOSE    On-line help file for the command: TESTC/CCD
%.VERSION    940722RHW created
%---------------------------------------------------------------------
\se
SECTION./CCD
\es\co
TESTC/CCD                                                       21-Jun-1994 RHW
\oc\su
TESTC/CCD in_frm [rows] x_pix [colums] y_pix
	Compute the horizontal and vertical charge transfer efficiency.
\us\pu
Purpose:    
	Compute the horizontal and vertical charge transfer efficiency.
\up\sy
Syntax:     
	TESTC/CCD in_frm [rows] x_pix [colums] y_pix
\ys\pa
        in_frm  = input flat frame. The frame should have an illumination level
                  as high as possible, however with being saturated
\ap\pa
        rows    = the range in y (rows) to be averaged into a single line and
                  to be used for computing the HCTE. Default all rows. 
                  In case of 0.0 as input the HCTE will not be computed.
\ap\pa
        x_pix   = in the x direction: first and last pixel of the image 
                  section on the CCD, and the coordinate for the first bias 
                  overscan pixel (all in pixel coordinates). No default.
\ap\pa
        columns = the range in x (columns) to be averaged into a single line 
                  and to be used for computing the VCTE. Default all columns. 
                  In case of 0,0 as input the VCTE will not be computed.
\ap\pa
        y_pix   = in the y direction: first and last pixel of the image 
                  section on the CCD, and the coordinate for the first bias 
                  overscan pixel (all in pixel coordinates). No default.
\ap\no
Note:
        For the HCTE the command first averages the rows given as the second
        parameter. From the x_range parameter the number of image pixels, the
        last image pixel and the first bias overscan pixel is obtained and 
        computes the HCTE according to the formula:\\
                   HCTE = 1 - bc/ic*ni, 
        where:\\
          - bs are the counts above the bias level in the first overscan 
            pixel in a row;\\
          - ic are the count above the bias level in the last image pixel in 
            a row;\\
          - ni are the number of image pixels in a row.
\\
        The values for the bias offset is extracted from the keyword
        {BIASMEAN}, and in computed by the command TESTB/CCD.\\
\\
        To determine the image section of the CCD and the overscan regions
        one can use the commands READ/IMAGE, PLOT/COLUMN and PLOT/ROW.\\
\\
        Note that the last column of a row is often slightly brighter than the 
        rest of the row (because the pixel is slightly larger).\\
\\
        The vertical charge transfer efficiency is computed in a similar way.
\on\see
See also:   
        TESTB/CCD, READ/IMAGE, PLOT/COLUMN, PLOT/ROW
\ees\exs
Examples:
\ex
        testc/ccd red0804 <,> 1,2067,2068 0,0
        Determine the HCTE from the frame red0804. The command will average
        all rows. The HCTE is computed using pixel 2068 as the first bias
        overscan pixel and pixel 2067 as the last image pixel. There are    
        2048 valied image pixels in the x direction. The VCTE is not computed.
\xe \sxe