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diff --git a/src/slalib/sun67.htx/node21.html b/src/slalib/sun67.htx/node21.html new file mode 100644 index 0000000..13ef3e2 --- /dev/null +++ b/src/slalib/sun67.htx/node21.html @@ -0,0 +1,264 @@ +<!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_AOPPA - Appt-to-Obs Parameters</TITLE> +<META NAME="description" CONTENT="SLA_AOPPA - Appt-to-Obs Parameters"> +<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="node22.html"> +<LINK REL="previous" HREF="node20.html"> +<LINK REL="up" HREF="node13.html"> +<LINK REL="next" HREF="node22.html"> +</HEAD> +<BODY > +<BR> <HR> +<A NAME="tex2html636" HREF="node22.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html634" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html628" HREF="node20.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="tex2html637" HREF="node22.html">SLA_AOPPAT - Update Appt-to-Obs Parameters</A> +<BR> +<B>Up:</B> <A NAME="tex2html635" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html629" HREF="node20.html">SLA_AOP - Apparent to Observed</A> +<BR> <HR> <P> +<P><!--End of Navigation Panel--> +<H2><A NAME="SECTION00048000000000000000">SLA_AOPPA - Appt-to-Obs Parameters</A> +<A NAME="xref_SLA_AOPPA"> </A><A NAME="SLA_AOPPA"> </A> +</H2> + <DL> +<DT><STRONG>ACTION:</STRONG> +<DD>Pre-compute the set of apparent to observed place parameters +required by the ``quick'' routines sla_AOPQK and sla_OAPQK. +<P> <DT><STRONG>CALL:</STRONG> +<DD><TT>CALL sla_AOPPA ( + DATE, DUT, ELONGM, PHIM, HM, XP, YP, + TDK, PMB, RH, WL, TLR, AOPRMS)</TT> +<P> </DL> +<P> <DL> +<DT><STRONG>GIVEN:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>DATE</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP>UTC date/time (Modified Julian Date, JD-2400000.5)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>DUT</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP><IMG WIDTH="16" HEIGHT="13" ALIGN="BOTTOM" BORDER="0" + SRC="img19.gif" + ALT="$\Delta$">UT: UT1-UTC (UTC seconds)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>ELONGM</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>observer's mean longitude (radians, east +ve)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>PHIM</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>observer's mean geodetic latitude (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>HM</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>observer's height above sea level (metres)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>XP,YP</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>polar motion <IMG WIDTH="42" HEIGHT="29" ALIGN="MIDDLE" BORDER="0" + SRC="img20.gif" + ALT="$[\,x,y\,]$"> coordinates (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>TDK</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>local ambient temperature (degrees K; std=273.155D0)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>PMB</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>local atmospheric pressure (mB; std=1013.25D0)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>RH</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>local relative humidity (in the range 0D0-1D0)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>WL</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>effective wavelength (<IMG WIDTH="26" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img21.gif" + ALT="$\mu{\rm m}$">, <I>e.g.</I> 0.55D0)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>TLR</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>tropospheric lapse rate (degrees K per metre, +<I>e.g.</I> 0.0065D0)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>RETURNED:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>AOPRMS</EM></TD> +<TH ALIGN="LEFT"><B>D(14)</B></TH> +<TD ALIGN="LEFT" NOWRAP>star-independent apparent-to-observed parameters:</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(1)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>geodetic latitude (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(2,3)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>sine and cosine of geodetic latitude</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(4)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>magnitude of diurnal aberration vector</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(5)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>height (HM)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(6)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>ambient temperature (TDK)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(7)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>pressure (PMB)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(8)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>relative humidity (RH)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(9)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>wavelength (WL)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(10)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>lapse rate (TLR)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(11,12)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>refraction constants A and B (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(13)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>longitude + eqn of equinoxes + +``sidereal <IMG WIDTH="16" HEIGHT="13" ALIGN="BOTTOM" BORDER="0" + SRC="img19.gif" + ALT="$\Delta$">UT'' (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1>(14)</TD> +<TD></TD> +<TD ALIGN="LEFT" NOWRAP>local apparent sidereal time (radians)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>NOTES:</STRONG> +<DD><DL COMPACT> +<DT>1. +<DD>It is advisable to take great care with units, as even +unlikely values of the input parameters are accepted and +processed in accordance with the models used. + <DT>2. +<DD>The DATE argument is UTC expressed as an MJD. This is, + strictly speaking, wrong, because of leap seconds. However, + as long as the <IMG WIDTH="16" HEIGHT="13" ALIGN="BOTTOM" BORDER="0" + SRC="img19.gif" + ALT="$\Delta$">UT and the UTC are consistent there + are no difficulties, except during a leap second. In this + case, the start of the 61st second of the final minute should + begin a new MJD day and the old pre-leap <IMG WIDTH="16" HEIGHT="13" ALIGN="BOTTOM" BORDER="0" + SRC="img19.gif" + ALT="$\Delta$">UT should + continue to be used. As the 61st second completes, the MJD + should revert to the start of the day as, simultaneously, + the <IMG WIDTH="16" HEIGHT="13" ALIGN="BOTTOM" BORDER="0" + SRC="img19.gif" + ALT="$\Delta$">UT changes by one second to its post-leap new value. + <DT>3. +<DD>The <IMG WIDTH="16" HEIGHT="13" ALIGN="BOTTOM" BORDER="0" + SRC="img19.gif" + ALT="$\Delta$">UT (UT1-UTC) is tabulated in IERS circulars and + elsewhere. It increases by exactly one second at the end of + each UTC leap second, introduced in order to keep <IMG WIDTH="16" HEIGHT="13" ALIGN="BOTTOM" BORDER="0" + SRC="img19.gif" + ALT="$\Delta$">UT + within <IMG WIDTH="15" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img30.gif" + ALT="$\pm$"><IMG WIDTH="24" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img31.gif" + ALT="$0^{\rm s}\hspace{-0.3em}.9$">. The ``sidereal <IMG WIDTH="16" HEIGHT="13" ALIGN="BOTTOM" BORDER="0" + SRC="img19.gif" + ALT="$\Delta$">UT'' which forms + part of AOPRMS(13) is the same quantity, but converted from solar + to sidereal seconds and expressed in radians. + <DT>4. +<DD>IMPORTANT - TAKE CARE WITH THE LONGITUDE SIGN CONVENTION. The + longitude required by the present routine is <B>east-positive</B>, + in accordance with geographical convention (and right-handed). + In particular, note that the longitudes returned by the + sla_OBS routine are west-positive (as in the <I>Astronomical + Almanac</I> before 1984) and must be reversed in sign before use in + the present routine. + <DT>5. +<DD>The polar coordinates XP,YP can be obtained from IERS + circulars and equivalent publications. The + maximum amplitude is about + <IMG WIDTH="23" HEIGHT="18" ALIGN="BOTTOM" BORDER="0" + SRC="img32.gif" + ALT="$0\hspace{-0.05em}^{'\hspace{-0.1em}'}\hspace{-0.4em}.3$"> . If XP,YP values + are unavailable, use XP=YP=0D0. See page B60 of the 1988 + <I>Astronomical Almanac</I> for a definition of the two angles. + <DT>6. +<DD>The height above sea level of the observing station, HM, + can be obtained from the <I>Astronomical Almanac</I> (Section J + in the 1988 edition), or via the routine sla_OBS. If P, + the pressure in mB, is available, an adequate + estimate of HM can be obtained from the following expression: + <BLOCKQUOTE><TT>HM=-29.3D0*TSL*LOG(P/1013.25D0)</TT> + </BLOCKQUOTE> + where TSL is the approximate sea-level air temperature in degrees K + (see <I>Astrophysical Quantities</I>, C.W.Allen, 3rd edition, + §52). Similarly, if the pressure P is not known, + it can be estimated from the height of the observing + station, HM as follows: + <BLOCKQUOTE><TT>P=1013.25D0*EXP(-HM/(29.3D0*TSL))</TT> + </BLOCKQUOTE> + Note, however, that the refraction is proportional to the + pressure and that an accurate P value is important for + precise work. + </DL></DL> +<BR> <HR> +<A NAME="tex2html636" HREF="node22.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html634" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html628" HREF="node20.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="tex2html637" HREF="node22.html">SLA_AOPPAT - Update Appt-to-Obs Parameters</A> +<BR> +<B>Up:</B> <A NAME="tex2html635" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html629" HREF="node20.html">SLA_AOP - Apparent to Observed</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> |