<!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>Filter descriptors</TITLE> <META NAME="description" CONTENT="Filter descriptors"> <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="node616.html"> <LINK REL="previous" HREF="node614.html"> <LINK REL="up" HREF="node614.html"> <LINK REL="next" HREF="node616.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html9207" HREF="node616.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html9204" HREF="node614.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html9198" HREF="node614.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html9206" 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="tex2html9208" HREF="node616.html">Descriptor NFILTCAR</A> <B> Up:</B> <A NAME="tex2html9205" HREF="node614.html">Instrument descriptors</A> <B> Previous:</B> <A NAME="tex2html9199" HREF="node614.html">Instrument descriptors</A> <BR> <BR> <!--End of Navigation Panel--> <H3><A NAME="SECTION003254100000000000000"> </A> <A NAME="sect-filt-desc"> </A> <BR> Filter descriptors </H3> The two most critical types of physical information needed about the filters themselves are (1) what are their transmission curves? and (2) does the instrument either regulate or measure their temperature? Filter temperature is important, because filters are somewhat more temperature-sensitive than detectors (see [<A HREF="node649.html#Y67">9</A>], and pp. 105-108 of [<A HREF="node649.html#Y74">10</A>]). In addition, we need to know how many different filter-code fields appear in the data. Bearing all this in mind, here are the descriptors for filters: <P> <BR><HR> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>