<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 98.1p1 release (March 2nd, 1998) originally by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>TESTC/CCD</TITLE> <META NAME="description" CONTENT="TESTC/CCD"> <META NAME="keywords" CONTENT="vol2"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <LINK REL="STYLESHEET" HREF="vol2.css"> <LINK REL="previous" HREF="node673.html"> <LINK REL="up" HREF="node668.html"> <LINK REL="next" HREF="node675.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html9917" HREF="node675.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html9914" HREF="node668.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html9910" HREF="node673.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html9916" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="icons.gif/contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html9918" HREF="node675.html">Commands in the CCD</A> <B> Up:</B> <A NAME="tex2html9915" HREF="node668.html">Test Commands</A> <B> Previous:</B> <A NAME="tex2html9911" HREF="node673.html">TESTS/CCD</A> <BR> <BR> <!--End of Navigation Panel--> <H3><A NAME="SECTION003511600000000000000"> <TT>TESTC/CCD</TT></A> </H3> This command produces an estimate of the bulk charge transfer efficiency in the horizontal (HCTE) and vertical direction (VCTE) (by the EPER method (Janesick et al., 1987)). For the HCTE the command first averages the rows given as the second parameter. The command uses 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: <BR><P></P> <DIV ALIGN="CENTER"> <!-- MATH: \begin{equation} HCTE = 1 - bc/ic*ni, \end{equation} --> <TABLE WIDTH="100%" ALIGN="CENTER"> <TR VALIGN="MIDDLE"><TD ALIGN="CENTER" NOWRAP> <I>HCTE</I> = 1 - <I>bc</I>/<I>ic</I>*<I>ni</I>, </TD> <TD WIDTH=10 ALIGN="RIGHT"> (27.2)</TD></TR> </TABLE> </DIV> <BR CLEAR="ALL"><P></P> where: <I>bc</I> are the counts above the bias level in the first overscan pixel in a row; <I>ic</I> are the count above the bias level in the last image pixel in a row; <I>ni</I> are the number of image pixels in a row. The values for the bias offset is extracted from the keyword <TT>BIASMEAN</TT>, and is computed by the command <TT>TESTB/CCD</TT>. To determine the image section of the CCD and the overscan regions one can use the commands <TT>READ/IMAGE</TT>, <TT>PLOT/COLUMN</TT> and <TT>PLOT/ROW</TT>. <P> 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. <P> <HR> <!--Navigation Panel--> <A NAME="tex2html9917" HREF="node675.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html9914" HREF="node668.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html9910" HREF="node673.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html9916" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="icons.gif/contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html9918" HREF="node675.html">Commands in the CCD</A> <B> Up:</B> <A NAME="tex2html9915" HREF="node668.html">Test Commands</A> <B> Previous:</B> <A NAME="tex2html9911" HREF="node673.html">TESTS/CCD</A> <!--End of Navigation Panel--> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>