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diff --git a/src/slalib/sun67.htx/node18.html b/src/slalib/sun67.htx/node18.html new file mode 100644 index 0000000..e3aee75 --- /dev/null +++ b/src/slalib/sun67.htx/node18.html @@ -0,0 +1,135 @@ +<!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_AMP - Apparent to Mean</TITLE> +<META NAME="description" CONTENT="SLA_AMP - Apparent to Mean"> +<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="node19.html"> +<LINK REL="previous" HREF="node17.html"> +<LINK REL="up" HREF="node13.html"> +<LINK REL="next" HREF="node19.html"> +</HEAD> +<BODY > +<BR> <HR> +<A NAME="tex2html606" HREF="node19.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html604" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html598" HREF="node17.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="tex2html607" HREF="node19.html">SLA_AMPQK - Quick Apparent to Mean</A> +<BR> +<B>Up:</B> <A NAME="tex2html605" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html599" HREF="node17.html">SLA_ALTAZ - Velocities etc. for Altazimuth Mount</A> +<BR> <HR> <P> +<P><!--End of Navigation Panel--> +<H2><A NAME="SECTION00045000000000000000">SLA_AMP - Apparent to Mean</A> +<A NAME="xref_SLA_AMP"> </A><A NAME="SLA_AMP"> </A> +</H2> + <DL> +<DT><STRONG>ACTION:</STRONG> +<DD>Convert star <IMG WIDTH="42" HEIGHT="29" ALIGN="MIDDLE" BORDER="0" + SRC="img3.gif" + ALT="$[\,\alpha,\delta\,]$"> from geocentric apparent to +mean place (post IAU 1976). +<P> <DT><STRONG>CALL:</STRONG> +<DD><TT>CALL sla_AMP (RA, DA, DATE, EQ, RM, DM)</TT> +<P> </DL> +<P> <DL> +<DT><STRONG>GIVEN:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>RA,DA</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP>apparent <IMG WIDTH="42" HEIGHT="29" ALIGN="MIDDLE" BORDER="0" + SRC="img3.gif" + ALT="$[\,\alpha,\delta\,]$"> (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>DATE</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>TDB for apparent place (JD-2400000.5)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>EQ</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>equinox: Julian epoch of mean place</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>RETURNED:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>RM,DM</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP>mean <IMG WIDTH="42" HEIGHT="29" ALIGN="MIDDLE" BORDER="0" + SRC="img3.gif" + ALT="$[\,\alpha,\delta\,]$"> (radians)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>NOTES:</STRONG> +<DD><DL COMPACT> +<DT>1. +<DD>The distinction between the required TDB and TT is +always negligible. Moreover, for all but the most +critical applications UTC is adequate. + <DT>2. +<DD>The accuracy is limited by the routine sla_EVP, called + by sla_MAPPA, which computes the Earth position and + velocity using the methods of Stumpff. The maximum + error is about 0.3 milliarcsecond. + <DT>3. +<DD>Iterative techniques are used for the aberration and + light deflection corrections so that the routines + sla_AMP (or sla_AMPQK) and sla_MAP (or sla_MAPQK) are + accurate inverses; even at the edge of the Sun's disc + the discrepancy is only about 1 nanoarcsecond. + <DT>4. +<DD>Where multiple apparent places are to be converted to + mean places, for a fixed date and equinox, it is more + efficient to use the sla_MAPPA routine to compute the + required parameters once, followed by one call to + sla_AMPQK per star. + </DL></DL> +<P> <DL> +<DT><STRONG>REFERENCES:</STRONG> +<DD><DL COMPACT> +<DT>1. +<DD>1984 <I>Astronomical Almanac</I>, pp B39-B41. +<DT>2. +<DD>Lederle & Schwan, 1984. <I>Astr.Astrophys.</I> <B>134</B>, 1-6. +</DL></DL> +<BR> <HR> +<A NAME="tex2html606" HREF="node19.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html604" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html598" HREF="node17.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="tex2html607" HREF="node19.html">SLA_AMPQK - Quick Apparent to Mean</A> +<BR> +<B>Up:</B> <A NAME="tex2html605" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html599" HREF="node17.html">SLA_ALTAZ - Velocities etc. for Altazimuth Mount</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> |