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diff --git a/src/slalib/sun67.htx/node163.html b/src/slalib/sun67.htx/node163.html new file mode 100644 index 0000000..4f6cf04 --- /dev/null +++ b/src/slalib/sun67.htx/node163.html @@ -0,0 +1,166 @@ +<!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_RCC - Barycentric Coordinate Time</TITLE> +<META NAME="description" CONTENT="SLA_RCC - Barycentric Coordinate Time"> +<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="node164.html"> +<LINK REL="previous" HREF="node162.html"> +<LINK REL="up" HREF="node13.html"> +<LINK REL="next" HREF="node164.html"> +</HEAD> +<BODY > +<BR> <HR> +<A NAME="tex2html2056" HREF="node164.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html2054" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html2048" HREF="node162.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="tex2html2057" HREF="node164.html">SLA_RDPLAN - Apparent of Planet</A> +<BR> +<B>Up:</B> <A NAME="tex2html2055" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html2049" HREF="node162.html">SLA_RANORM - Put Angle into Range</A> +<BR> <HR> <P> +<P><!--End of Navigation Panel--> +<H2><A NAME="SECTION0004150000000000000000">SLA_RCC - Barycentric Coordinate Time</A> +<A NAME="xref_SLA_RCC"> </A><A NAME="SLA_RCC"> </A> +</H2> + <DL> +<DT><STRONG>CALL:</STRONG> +<DD><TT>D = sla_RCC (TDB, UT1, WL, U, V)</TT> +<DT><STRONG>ACTION:</STRONG> +<DD>The relativistic clock correction TDB-TT, the + difference between <I>proper time</I> + on Earth and <I>coordinate time</I> in the solar system barycentric + space-time frame of reference. The proper time is TT; the + coordinate time is <I>an implementation</I> of TDB. +<P> </DL> +<P> <DL> +<DT><STRONG>GIVEN:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>TDB</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP>coordinate time (MJD: JD-2400000.5)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>UT1</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>universal time (fraction of one day)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>WL</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>clock longitude (radians west)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>U</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>clock distance from Earth spin axis (km)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>V</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>clock distance north of Earth equatorial plane (km)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>RETURNED:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>sla_RCC</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP>TDB-TT (sec)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>NOTES:</STRONG> +<DD><DL COMPACT> +<DT>1. +<DD>TDB may be considered to +be the coordinate time in the solar system barycentre frame of +reference, and TT is the proper time given by clocks at mean sea + level on the Earth. + <DT>2. +<DD>The result has a main (annual) sinusoidal term of amplitude + approximately 1.66ms, plus planetary terms up to about + 20<IMG WIDTH="12" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img146.gif" + ALT="$\mu$">s, and lunar and diurnal terms up to 2<IMG WIDTH="12" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img146.gif" + ALT="$\mu$">s. The + variation arises from the transverse Doppler effect and the + gravitational red-shift as the observer varies in speed and + moves through different gravitational potentials. + <DT>3. +<DD>The argument TDB is, strictly, the barycentric coordinate time; + however, the terrestrial proper time (TT) can in practice be used. + <DT>4. +<DD>The geocentric model is that of Fairhead & Bretagnon (1990), + in its full + form. It was supplied by Fairhead (private communication) + as a Fortran subroutine. A number of coding changes were made to + this subroutine in order + match the calling sequence of previous versions of the present + routine, to comply with Starlink programming standards and to + avoid compilation problems on certain machines. On the supported + computer types, + the numerical results are essentially unaffected by the + changes. The topocentric model is from Moyer (1981) and Murray (1983). + During the interval 1950-2050, the absolute accuracy of the + geocentric model is better than <IMG WIDTH="23" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img147.gif" + ALT="$\pm3$"> nanoseconds + relative to direct numerical integrations using the JPL DE200/LE200 + solar system ephemeris. + <DT>5. +<DD>The IAU definition of TDB is that it must differ from TT only by + periodic terms. Though practical, this is an imprecise definition + which ignores the existence of very long-period and secular effects + in the dynamics of the solar system. As a consequence, different + implementations of TDB will, in general, differ in zero-point and + will drift linearly relative to one other. + </DL></DL> +<P> <DL> +<DT><STRONG>REFERENCES:</STRONG> +<DD><DL COMPACT> +<DT>1. +<DD>Fairhead, L. & +Bretagnon, P., 1990. <I>Astr.Astrophys.</I> <B>229</B>, 240-247. +<DT>2. +<DD>Moyer, T.D., 1981. <I>Cel.Mech.</I> <B>23</B>, 33. + <DT>3. +<DD>Murray, C.A., 1983, <I>Vectorial Astrometry</I>, Adam Hilger. + </DL></DL> +<BR> <HR> +<A NAME="tex2html2056" HREF="node164.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html2054" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html2048" HREF="node162.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="tex2html2057" HREF="node164.html">SLA_RDPLAN - Apparent of Planet</A> +<BR> +<B>Up:</B> <A NAME="tex2html2055" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html2049" HREF="node162.html">SLA_RANORM - Put Angle into Range</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> |