<!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>Resampling the Data</TITLE> <META NAME="description" CONTENT="Resampling the Data"> <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="node130.html"> <LINK REL="up" HREF="node127.html"> <LINK REL="next" HREF="node132.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html3080" HREF="node132.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html3077" HREF="node127.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html3073" HREF="node130.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html3079" 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="tex2html3081" HREF="node132.html">Sky Subtraction</A> <B> Up:</B> <A NAME="tex2html3078" HREF="node127.html">Geometric Correction</A> <B> Previous:</B> <A NAME="tex2html3074" HREF="node130.html">Distortion Along the Slit</A> <BR> <BR> <!--End of Navigation Panel--> <H2><A NAME="SECTION001034000000000000000"> Resampling the Data</A> </H2> <P> In the standard row-by-row option, the dispersion coefficients are kept in the table (<TT>coerbr.tbl</TT>). The rebinning to constant step in wavelength is accomplished, row by row, with the command <TT>REBIN/LONG</TT>. <P> If the 2-D option described above for the solution of the dispersion relation is followed (<TT>TWODOPT=YES</TT>), the polynomial coefficients in both directions are stored in the keywords <TT>KEYLONGD</TT> and <TT>COEFYD</TT>, respectively. This information is then used by the command <TT>RECTIFY/LONG</TT> to resample the image in the <!-- MATH: $(\lambda, s)$ --> <IMG WIDTH="10" HEIGHT="44" ALIGN="MIDDLE" BORDER="0" SRC="img258.gif" ALT="$(\lambda, s)$"> space. <P> Data resampling<A NAME="5841"> </A> can be avoided by the command <TT>APPLY/DISPERSION</TT> which generates a table with the columns <TT>:WAVE</TT> and <TT>:FLUX</TT>, each row corresponding to the central wavelength and flux of a CCD detector pixel. <P> <BR><HR> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>
