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diff --git a/src/slalib/sun67.htx/node115.html b/src/slalib/sun67.htx/node115.html new file mode 100644 index 0000000..cee01cc --- /dev/null +++ b/src/slalib/sun67.htx/node115.html @@ -0,0 +1,115 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> +<!--Converted with LaTeX2HTML 97.1 (release) (July 13th, 1997) + 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 Lippman, Marek Rouchal, Martin Wilck and others --> +<HTML> +<HEAD> +<TITLE>SLA_GMST - UT to GMST</TITLE> +<META NAME="description" CONTENT="SLA_GMST - UT to GMST"> +<META NAME="keywords" CONTENT="sun67"> +<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="sun67.css"> +<LINK REL="next" HREF="node116.html"> +<LINK REL="previous" HREF="node114.html"> +<LINK REL="up" HREF="node13.html"> +<LINK REL="next" HREF="node116.html"> +</HEAD> +<BODY > +<BR> <HR> +<A NAME="tex2html1576" HREF="node116.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html1574" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html1568" HREF="node114.html"> +<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="previous_motif.gif"></A> <A HREF="sun67.html#stardoccontents"><IMG ALIGN="BOTTOM" BORDER="0" + SRC="contents_motif.gif"></A> +<BR> +<B> Next:</B> <A NAME="tex2html1577" HREF="node116.html">SLA_GMSTA - UT to GMST (extra precision)</A> +<BR> +<B>Up:</B> <A NAME="tex2html1575" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html1569" HREF="node114.html">SLA_GEOC - Geodetic to Geocentric</A> +<BR> <HR> <P> +<P><!--End of Navigation Panel--> +<H2><A NAME="SECTION0004102000000000000000">SLA_GMST - UT to GMST</A> +<A NAME="xref_SLA_GMST"> </A><A NAME="SLA_GMST"> </A> +</H2> + <DL> +<DT><STRONG>ACTION:</STRONG> +<DD>Conversion from universal time UT1 to Greenwich mean +sidereal time. +<P> <DT><STRONG>CALL:</STRONG> +<DD><TT>D = sla_GMST (UT1)</TT> +<P> </DL> +<P> <DL> +<DT><STRONG>GIVEN:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>UT1</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP>universal time (strictly UT1) expressed as +modified Julian Date (JD-2400000.5)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>RETURNED:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>sla_GMST</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP>Greenwich mean sidereal time (radians)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>NOTES:</STRONG> +<DD><DL COMPACT> +<DT>1. +<DD>The IAU 1982 expression +(see page S15 of the 1984 <I>Astronomical +Almanac</I>) is used, but rearranged to reduce rounding errors. This + expression is always described as giving the GMST at <IMG WIDTH="18" HEIGHT="17" ALIGN="BOTTOM" BORDER="0" + SRC="img49.gif" + ALT="$0^{\rm h}$">UT; + in fact, it gives the difference between the + GMST and the UT, which happens to equal the GMST (modulo + 24 hours) at <IMG WIDTH="18" HEIGHT="17" ALIGN="BOTTOM" BORDER="0" + SRC="img49.gif" + ALT="$0^{\rm h}$">UT each day. In sla_GMST, the + entire UT is used directly as the argument for the + canonical formula, and the fractional part of the UT is + added separately; note that the factor <IMG WIDTH="94" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img120.gif" + ALT="$1.0027379\cdots$"> does + not appear. + <DT>2. +<DD>See also the routine sla_GMSTA, which + delivers better numerical + precision by accepting the UT date and time as separate arguments. + </DL></DL> +<BR> <HR> +<A NAME="tex2html1576" HREF="node116.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html1574" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html1568" HREF="node114.html"> +<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="previous_motif.gif"></A> <A HREF="sun67.html#stardoccontents"><IMG ALIGN="BOTTOM" BORDER="0" + SRC="contents_motif.gif"></A> +<BR> +<B> Next:</B> <A NAME="tex2html1577" HREF="node116.html">SLA_GMSTA - UT to GMST (extra precision)</A> +<BR> +<B>Up:</B> <A NAME="tex2html1575" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html1569" HREF="node114.html">SLA_GEOC - Geodetic to Geocentric</A> +<BR> <HR> <P> +<P><!--End of Navigation Panel--> +<ADDRESS> +<I>SLALIB --- Positional Astronomy Library<BR>Starlink User Note 67<BR>P. T. Wallace<BR>12 October 1999<BR>E-mail:ptw@star.rl.ac.uk</I> +</ADDRESS> +</BODY> +</HTML> |