<!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>Seeing</TITLE> <META NAME="description" CONTENT="Seeing"> <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="node648.html"> <LINK REL="previous" HREF="node646.html"> <LINK REL="up" HREF="node640.html"> <LINK REL="next" HREF="node648.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html9584" HREF="node648.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html9581" HREF="node640.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html9575" HREF="node646.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html9583" 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="tex2html9585" HREF="node648.html">Error estimates</A> <B> Up:</B> <A NAME="tex2html9582" HREF="node640.html">Additional information</A> <B> Previous:</B> <A NAME="tex2html9576" HREF="node646.html">Geneva parameters</A> <BR> <BR> <!--End of Navigation Panel--> <H3><A NAME="SECTION003262700000000000000"> Seeing</A> </H3> Sometimes seeing estimates are available, either from the observer at the eyepiece, or from a nearby seeing monitor. It might also be estimated from the core widths of images on CCD frames. Such values should go in a column headed SEEING. <P> While quantitative measures, such as FWHM in seconds of arc, are most useful, it may still be possible to obtain usable information from seeing expressed on some arbitrary scale. One should be careful not to mix the two types, or to intermix seeing estimated on different scales. <P> <BR><HR> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>
