<!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>Preparing Your Calibration Frames</TITLE> <META NAME="description" CONTENT="Preparing Your Calibration 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="node50.html"> <LINK REL="previous" HREF="node41.html"> <LINK REL="up" HREF="node31.html"> <LINK REL="next" HREF="node43.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html1970" HREF="node43.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html1967" HREF="node31.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html1961" HREF="node41.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html1969" 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="tex2html1971" HREF="node43.html">Input and Output</A> <B> Up:</B> <A NAME="tex2html1968" HREF="node31.html">CCD Reductions</A> <B> Previous:</B> <A NAME="tex2html1962" HREF="node41.html">Basic Reduction Steps</A> <BR> <BR> <!--End of Navigation Panel--> <H1><A NAME="SECTION00680000000000000000"> </A> <A NAME="ccd:preparing-your-calibration-frames"> </A> <BR> Preparing Your Calibration Frames </H1> Before the actual processing can start, multiple calibration frames have to be combined into a master. The command that takes care of combining the calibration frames in the CCD package is <TT>COMBINE/CCD</TT>. It provides various methods to improve the S/N statistics in the resulting output frame. Depending on the actual parameter settings, the command can take into account the exposure times in the combining process, and can adjust for a (variable) sky background. <P> <BR><HR> <!--Table of Child-Links--> <A NAME="CHILD_LINKS"> </A> <UL> <LI><A NAME="tex2html1972" HREF="node43.html">Input and Output</A> <LI><A NAME="tex2html1973" HREF="node44.html">Combining Methods</A> <LI><A NAME="tex2html1974" HREF="node45.html">Combining Bias Frames</A> <LI><A NAME="tex2html1975" HREF="node46.html">Combining Dark Frames</A> <LI><A NAME="tex2html1976" HREF="node47.html">Combining Flat Fields</A> <LI><A NAME="tex2html1977" HREF="node48.html">Combining Sky Frames</A> <LI><A NAME="tex2html1978" HREF="node49.html">Combine Example</A> </UL> <!--End of Table of Child-Links--> <BR><HR> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>
