<!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>Refining the Dispersion Relation</TITLE> <META NAME="description" CONTENT="Refining the Dispersion Relation"> <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="node511.html"> <LINK REL="up" HREF="node507.html"> <LINK REL="next" HREF="node513.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html7851" HREF="node513.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html7848" HREF="node507.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html7844" HREF="node511.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html7850" 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="tex2html7852" HREF="node513.html">Resampling in Wavelength</A> <B> Up:</B> <A NAME="tex2html7849" HREF="node507.html">Getting the Dispersion Solution</A> <B> Previous:</B> <A NAME="tex2html7845" HREF="node511.html">Possible Graphical Verifications</A> <BR> <BR> <!--End of Navigation Panel--> <H3><A NAME="SECTION003034500000000000000"> Refining the Dispersion Relation</A> </H3> <P> Due to discontinuities in the line detections as well as in the calibration process, the dispersion relations computed by the row-by-row process could show row-to-row discontinuous variations. The command <TT>CALIBRATE/TWICE</TT>, provided that a sufficient number of calibration lines is available, can stabilize the solutions by performing a two-pass wavelength calibration which retains for the second pass only the lines that were consistently identified during the first pass. <P> <BR><HR> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>