<!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>Combining Bias Frames</TITLE> <META NAME="description" CONTENT="Combining Bias Frames"> <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="next" HREF="node46.html"> <LINK REL="previous" HREF="node44.html"> <LINK REL="up" HREF="node42.html"> <LINK REL="next" HREF="node46.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html2010" HREF="node46.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html2007" HREF="node42.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html2001" HREF="node44.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html2009" 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="tex2html2011" HREF="node46.html">Combining Dark Frames</A> <B> Up:</B> <A NAME="tex2html2008" HREF="node42.html">Preparing Your Calibration Frames</A> <B> Previous:</B> <A NAME="tex2html2002" HREF="node44.html">Combining Methods</A> <BR> <BR> <!--End of Navigation Panel--> <H2><A NAME="SECTION00683000000000000000"> </A> <A NAME="ccd:combining-bias-frames"> </A> <BR> Combining Bias Frames </H2> Combination of the bias frames is straight forward: filters used and integration times do not play a role, and in most cases the bias frames can be treated with the same weight. The default keyword setting for the bias combining is displayed in Table <A HREF="node45.html#ccd:bias-keywords">3.4</A>. <P> <BR> <DIV ALIGN="CENTER"><A NAME="1821"> </A> <TABLE> <CAPTION><STRONG>Table 3.4:</STRONG> Keywords for combining bias calibration frames</CAPTION> <TR><TD> <DIV ALIGN="CENTER"> <TABLE CELLPADDING=3 BORDER="1" ALIGN="CENTER"> <TR><TH ALIGN="LEFT"><B>Keyword </B></TH> <TH ALIGN="LEFT"><B>Content </B></TH> <TH ALIGN="LEFT"><B>Default </B></TH> <TH ALIGN="LEFT"><B>Description </B></TH> </TR> <TR><TD ALIGN="LEFT"><TT> CCD_IN</TT></TD> <TD ALIGN="LEFT">input name</TD> <TD ALIGN="LEFT">?</TD> <TD ALIGN="LEFT">table of input frames</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_TYP</TT></TD> <TD ALIGN="LEFT">descriptor value</TD> <TD ALIGN="LEFT">*</TD> <TD ALIGN="LEFT">exposure type to check, if any</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_SIG</TT></TD> <TD ALIGN="LEFT">yes|no</TD> <TD ALIGN="LEFT">no</TD> <TD ALIGN="LEFT">create sigma image</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_MET</TT></TD> <TD ALIGN="LEFT">comb. method</TD> <TD ALIGN="LEFT">maxrej</TD> <TD ALIGN="LEFT">type of combining operation</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_DEL</TT></TD> <TD ALIGN="LEFT">yes|no</TD> <TD ALIGN="LEFT">no</TD> <TD ALIGN="LEFT">delete cal. frames afterwards</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_STA</TT></TD> <TD ALIGN="LEFT">mean|median|mode</TD> <TD ALIGN="LEFT">mode</TD> <TD ALIGN="LEFT">correct. by Mode/Median/Mean</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_EXP</TT></TD> <TD ALIGN="LEFT">yes|no</TD> <TD ALIGN="LEFT">no</TD> <TD ALIGN="LEFT">scale by exposure time</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_SCA</TT></TD> <TD ALIGN="LEFT">yes|no</TD> <TD ALIGN="LEFT">no</TD> <TD ALIGN="LEFT">scale by MMM</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_OFF</TT></TD> <TD ALIGN="LEFT">yes|no</TD> <TD ALIGN="LEFT">no</TD> <TD ALIGN="LEFT">add offset from MMM</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_WEI</TT></TD> <TD ALIGN="LEFT">yes|no</TD> <TD ALIGN="LEFT">yes</TD> <TD ALIGN="LEFT">use a weighted average</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_SEC</TT></TD> <TD ALIGN="LEFT">area</TD> <TD ALIGN="LEFT">[<,<:>,>]</TD> <TD ALIGN="LEFT">area for finding MMM</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_RAN</TT></TD> <TD ALIGN="LEFT">real,real</TD> <TD ALIGN="LEFT">-99999,99999</TD> <TD ALIGN="LEFT">valid pixel range</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_CLP</TT></TD> <TD ALIGN="LEFT">real</TD> <TD ALIGN="LEFT">3.,3.</TD> <TD ALIGN="LEFT">low/high sigma clipping factor</TD> </TR> <TR><TD ALIGN="LEFT"><TT> BS_NUL</TT></TD> <TD ALIGN="LEFT">real</TD> <TD ALIGN="LEFT"><TT> NULL(2)</TT></TD> <TD ALIGN="LEFT">value for rejections</TD> </TR> </TABLE></DIV> <A NAME="ccd:bias-keywords"> </A> </TD></TR> </TABLE> </DIV> <BR> <P> <HR> <!--Navigation Panel--> <A NAME="tex2html2010" HREF="node46.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html2007" HREF="node42.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html2001" HREF="node44.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html2009" 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="tex2html2011" HREF="node46.html">Combining Dark Frames</A> <B> Up:</B> <A NAME="tex2html2008" HREF="node42.html">Preparing Your Calibration Frames</A> <B> Previous:</B> <A NAME="tex2html2002" HREF="node44.html">Combining Methods</A> <!--End of Navigation Panel--> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>
