<!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 and checking the results</TITLE> <META NAME="description" CONTENT="Resampling and checking the results"> <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="node162.html"> <LINK REL="up" HREF="node158.html"> <LINK REL="next" HREF="node164.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html3467" HREF="node164.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html3464" HREF="node158.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html3460" HREF="node162.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html3466" 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="tex2html3468" HREF="node164.html">Flat Field Correction</A> <B> Up:</B> <A NAME="tex2html3465" HREF="node158.html">Wavelength Calibration</A> <B> Previous:</B> <A NAME="tex2html3461" HREF="node162.html">Identification loop</A> <BR> <BR> <!--End of Navigation Panel--> <H2><A NAME="SECTION001165000000000000000"> Resampling and checking the results</A> </H2> <P> The extracted orders in the pixel domain can be resampled into wavelengths with the command <TT>REBIN/ECHELLE</TT>. Several quality checks are provided by the command <TT>IDENT/ECH</TT>. Residuals are visualized with the command <TT>PLOT/RESIDUAL</TT>. A method to verify the wavelength calibration consists of extracting and resampling the wavelength calibration frame and displaying the resampled image with a large scaling factor on the Y-axis. The variation of wavelength coverage from one order to the next should be smooth. Different regions of the resampled image and in particular the overlaps can be verified with the command <TT>PLOT/SPECTRUM</TT>. <P> <BR><HR> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>