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diff --git a/src/slalib/sun67.htx/node166.html b/src/slalib/sun67.htx/node166.html new file mode 100644 index 0000000..4dd74d2 --- /dev/null +++ b/src/slalib/sun67.htx/node166.html @@ -0,0 +1,428 @@ +<!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_REFCOQ - Refraction Constants (fast)</TITLE> +<META NAME="description" CONTENT="SLA_REFCOQ - Refraction Constants (fast)"> +<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="node167.html"> +<LINK REL="previous" HREF="node165.html"> +<LINK REL="up" HREF="node13.html"> +<LINK REL="next" HREF="node167.html"> +</HEAD> +<BODY > +<BR> <HR> +<A NAME="tex2html2086" HREF="node167.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html2084" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html2078" HREF="node165.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="tex2html2087" HREF="node167.html">SLA_REFRO - Refraction</A> +<BR> +<B>Up:</B> <A NAME="tex2html2085" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html2079" HREF="node165.html">SLA_REFCO - Refraction Constants</A> +<BR> <HR> <P> +<P><!--End of Navigation Panel--> +<H2><A NAME="SECTION0004153000000000000000">SLA_REFCOQ - Refraction Constants (fast)</A> +<A NAME="xref_SLA_REFCOQ"> </A><A NAME="SLA_REFCOQ"> </A> +</H2> + <DL> +<DT><STRONG>ACTION:</STRONG> +<DD>Determine the constants <I>a</I> and <I>b</I> in the +atmospheric refraction model + <IMG WIDTH="164" HEIGHT="31" ALIGN="MIDDLE" BORDER="0" + SRC="img148.gif" + ALT="$\Delta \zeta = a \tan \zeta + b \tan^{3} \zeta$">, where <IMG WIDTH="11" HEIGHT="27" ALIGN="MIDDLE" BORDER="0" + SRC="img149.gif" + ALT="$\zeta$"> is the <I>observed</I> zenith distance + (<I>i.e.</I> affected by refraction) and <IMG WIDTH="24" HEIGHT="27" ALIGN="MIDDLE" BORDER="0" + SRC="img150.gif" + ALT="$\Delta \zeta$"> is + what to add to <IMG WIDTH="11" HEIGHT="27" ALIGN="MIDDLE" BORDER="0" + SRC="img149.gif" + ALT="$\zeta$"> to give the <I>topocentric</I> + (<I>i.e. in vacuo</I>) zenith distance. (This is a fast + alternative to the sla_REFCO routine - see notes.) +<P> <DT><STRONG>CALL:</STRONG> +<DD><TT>CALL sla_REFCOQ (TDK, PMB, RH, WL, REFA, REFB)</TT> +<P> </DL> +<P> <DL> +<DT><STRONG>GIVEN:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>TDK</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP>ambient temperature at the observer (degrees K)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>PMB</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>pressure at the observer (mB)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>RH</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>relative humidity at the observer (range 0-1)</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 of the source (<IMG WIDTH="26" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img21.gif" + ALT="$\mu{\rm m}$">)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>RETURNED:</STRONG> +<DD> +<BR> +<TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>REFA</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP><IMG WIDTH="37" HEIGHT="27" ALIGN="MIDDLE" BORDER="0" + SRC="img151.gif" + ALT="$\tan \zeta$"> coefficient (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>REFB</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP><IMG WIDTH="44" HEIGHT="31" ALIGN="MIDDLE" BORDER="0" + SRC="img152.gif" + ALT="$\tan^{3} \zeta$"> coefficient (radians)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>NOTES:</STRONG> +<DD><DL COMPACT> +<DT>1. +<DD>The radio refraction is chosen by specifying WL >100 <IMG WIDTH="26" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img21.gif" + ALT="$\mu{\rm m}$">.<DT>2. +<DD>The model is an approximation, for moderate zenith distances, +to the predictions of the sla_REFRO routine. The approximation + is maintained across a range of conditions, and applies to + both optical/IR and radio. + <DT>3. +<DD>The algorithm is a fast alternative to the sla_REFCO routine. + The latter calls the sla_REFRO routine itself: this involves + integrations through a model atmosphere, and is costly in + processor time. However, the model which is produced is precisely + correct for two zenith distances (<IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img154.gif" + ALT="$45^\circ$"> and <IMG WIDTH="40" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img161.gif" + ALT="$\sim\!76^\circ$">) and at other zenith distances is limited in accuracy only by the + <IMG WIDTH="164" HEIGHT="31" ALIGN="MIDDLE" BORDER="0" + SRC="img148.gif" + ALT="$\Delta \zeta = a \tan \zeta + b \tan^{3} \zeta$"> formulation + itself. The present routine is not as accurate, though it + satisfies most practical requirements. + <DT>4. +<DD>The model omits the effects of (i) height above sea level (apart + from the reduced pressure itself), (ii) latitude (<I>i.e.</I> the + flattening of the Earth) and (iii) variations in tropospheric + lapse rate. + <DT>5. +<DD>The model has been tested using the following range of conditions: + <DL COMPACT> +<DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>lapse rates 0.0055, 0.0065, 0.0075 degrees K per metre +<DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>latitudes <IMG WIDTH="18" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img1.gif" + ALT="$0^{\circ}$">, <IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img162.gif" + ALT="$25^\circ$">, <IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img163.gif" + ALT="$50^\circ$">, <IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img164.gif" + ALT="$75^\circ$"> <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>heights 0, 2500, 5000 metres above sea level + <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>pressures mean for height -10% to +5% in steps of 5% + <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>temperatures <IMG WIDTH="38" HEIGHT="27" ALIGN="MIDDLE" BORDER="0" + SRC="img165.gif" + ALT="$-10^\circ$"> to <IMG WIDTH="38" HEIGHT="27" ALIGN="MIDDLE" BORDER="0" + SRC="img166.gif" + ALT="$+20^\circ$"> with respect to + <IMG WIDTH="34" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img167.gif" + ALT="$280^\circ$">K at sea level + <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>relative humidity 0, 0.5, 1 + <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>wavelength 0.4, 0.6, ... <IMG WIDTH="34" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img168.gif" + ALT="$2\mu{\rm m}$">, + radio + <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>zenith distances <IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img39.gif" + ALT="$15^\circ$">, <IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img154.gif" + ALT="$45^\circ$">, <IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img164.gif" + ALT="$75^\circ$"></DL> + For the above conditions, the comparison with sla_REFRO + was as follows: +<P> <BR> +<BR> +<BR> +<P> + <TABLE CELLPADDING=3 BORDER="1"> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP> </TD> +<TH ALIGN="RIGHT" NOWRAP><I>worst</I></TH> +<TH ALIGN="RIGHT" NOWRAP><I>RMS</I></TH> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>optical/IR</TD> +<TD ALIGN="RIGHT" NOWRAP>62</TD> +<TD ALIGN="RIGHT" NOWRAP>8</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>radio</TD> +<TD ALIGN="RIGHT" NOWRAP>319</TD> +<TD ALIGN="RIGHT" NOWRAP>49</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP> </TD> +<TD ALIGN="RIGHT" NOWRAP>mas</TD> +<TD ALIGN="RIGHT" NOWRAP>mas</TD> +</TR> +</TABLE> +<P> <BR> +<BR> +<BR> +<BR> +<P> +For this particular set of conditions: + <DL COMPACT> +<DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>lapse rate <IMG WIDTH="86" HEIGHT="17" ALIGN="BOTTOM" BORDER="0" + SRC="img169.gif" + ALT="$6.5^\circ K km^{-1}$"><DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>latitude <IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img163.gif" + ALT="$50^\circ$"> <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>sea level + <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>pressure 1005mB + <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>temperature <IMG WIDTH="18" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img170.gif" + ALT="$7^\circ$">C + <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>humidity 80% + <DT><IMG WIDTH="7" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img72.gif" + ALT="$\cdot$"><DD>wavelength 5740A + </DL> + the results were as follows: +<P> <BR> +<BR> +<BR> +<P> + <TABLE CELLPADDING=3 BORDER="1"> +<TR VALIGN="TOP"><TD ALIGN="CENTER" NOWRAP COLSPAN=1><IMG WIDTH="11" HEIGHT="27" ALIGN="MIDDLE" BORDER="0" + SRC="img149.gif" + ALT="$\zeta$"></TD> +<TD ALIGN="CENTER" NOWRAP COLSPAN=1>sla_REFRO</TD> +<TD ALIGN="CENTER" NOWRAP COLSPAN=1>sla_REFCOQ</TD> +<TD ALIGN="CENTER" NOWRAP COLSPAN=1>Saastamoinen</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>10</TD> +<TD ALIGN="RIGHT" NOWRAP>10.27</TD> +<TD ALIGN="RIGHT" NOWRAP>10.27</TD> +<TD ALIGN="RIGHT" NOWRAP>10.27</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>20</TD> +<TD ALIGN="RIGHT" NOWRAP>21.19</TD> +<TD ALIGN="RIGHT" NOWRAP>21.20</TD> +<TD ALIGN="RIGHT" NOWRAP>21.19</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>30</TD> +<TD ALIGN="RIGHT" NOWRAP>33.61</TD> +<TD ALIGN="RIGHT" NOWRAP>33.61</TD> +<TD ALIGN="RIGHT" NOWRAP>33.60</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>40</TD> +<TD ALIGN="RIGHT" NOWRAP>48.82</TD> +<TD ALIGN="RIGHT" NOWRAP>48.83</TD> +<TD ALIGN="RIGHT" NOWRAP>48.81</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>45</TD> +<TD ALIGN="RIGHT" NOWRAP>58.16</TD> +<TD ALIGN="RIGHT" NOWRAP>58.18</TD> +<TD ALIGN="RIGHT" NOWRAP>58.16</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>50</TD> +<TD ALIGN="RIGHT" NOWRAP>69.28</TD> +<TD ALIGN="RIGHT" NOWRAP>69.30</TD> +<TD ALIGN="RIGHT" NOWRAP>69.27</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>55</TD> +<TD ALIGN="RIGHT" NOWRAP>82.97</TD> +<TD ALIGN="RIGHT" NOWRAP>82.99</TD> +<TD ALIGN="RIGHT" NOWRAP>82.95</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>60</TD> +<TD ALIGN="RIGHT" NOWRAP>100.51</TD> +<TD ALIGN="RIGHT" NOWRAP>100.54</TD> +<TD ALIGN="RIGHT" NOWRAP>100.50</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>65</TD> +<TD ALIGN="RIGHT" NOWRAP>124.23</TD> +<TD ALIGN="RIGHT" NOWRAP>124.26</TD> +<TD ALIGN="RIGHT" NOWRAP>124.20</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>70</TD> +<TD ALIGN="RIGHT" NOWRAP>158.63</TD> +<TD ALIGN="RIGHT" NOWRAP>158.68</TD> +<TD ALIGN="RIGHT" NOWRAP>158.61</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>72</TD> +<TD ALIGN="RIGHT" NOWRAP>177.32</TD> +<TD ALIGN="RIGHT" NOWRAP>177.37</TD> +<TD ALIGN="RIGHT" NOWRAP>177.31</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>74</TD> +<TD ALIGN="RIGHT" NOWRAP>200.35</TD> +<TD ALIGN="RIGHT" NOWRAP>200.38</TD> +<TD ALIGN="RIGHT" NOWRAP>200.32</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>76</TD> +<TD ALIGN="RIGHT" NOWRAP>229.45</TD> +<TD ALIGN="RIGHT" NOWRAP>229.43</TD> +<TD ALIGN="RIGHT" NOWRAP>229.42</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>78</TD> +<TD ALIGN="RIGHT" NOWRAP>267.44</TD> +<TD ALIGN="RIGHT" NOWRAP>267.29</TD> +<TD ALIGN="RIGHT" NOWRAP>267.41</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>80</TD> +<TD ALIGN="RIGHT" NOWRAP>319.13</TD> +<TD ALIGN="RIGHT" NOWRAP>318.55</TD> +<TD ALIGN="RIGHT" NOWRAP>319.10</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>deg</TD> +<TD ALIGN="RIGHT" NOWRAP>arcsec</TD> +<TD ALIGN="RIGHT" NOWRAP>arcsec</TD> +<TD ALIGN="RIGHT" NOWRAP>arcsec</TD> +</TR> +</TABLE> +<P> <BR> +<BR> +<BR> +<BR> +<P> +The values for Saastamoinen's formula (which includes terms + up to <IMG WIDTH="33" HEIGHT="16" ALIGN="BOTTOM" BORDER="0" + SRC="img171.gif" + ALT="$\tan^5$">) are taken from Hohenkerk and Sinclair (1985). +<P> +The results from the much slower but more accurate sla_REFCO + routine have not been included in the tabulation as they are + identical to those in the sla_REFRO column to the + <IMG WIDTH="31" HEIGHT="18" ALIGN="BOTTOM" BORDER="0" + SRC="img158.gif" + ALT="$0\hspace{-0.05em}^{'\hspace{-0.1em}'}\hspace{-0.4em}.01$"><P> +resolution used. + <DT>6. +<DD>Outlandish input parameters are silently limited + to mathematically safe values. Zero pressure is permissible, + and causes zeroes to be returned. + <DT>7. +<DD>The algorithm draws on several sources, as follows: + <UL> +<LI> The formula for the saturation vapour pressure of water as + a function of temperature and temperature is taken from + expressions A4.5-A4.7 of Gill (1982). +<LI> The formula for the water vapour pressure, given the + saturation pressure and the relative humidity is from + Crane (1976), expression 2.5.5. +<LI> The refractivity of air is a function of temperature, + total pressure, water-vapour pressure and, in the case + of optical/IR but not radio, wavelength. The formulae + for the two cases are developed from the Essen and Froome + expressions adopted in Resolution 1 of the 12th International + Geodesy Association General Assembly (1963). + </UL> + The above three items are as used in the sla_REFRO routine. + <UL> +<LI> The formula for <IMG WIDTH="91" HEIGHT="29" ALIGN="MIDDLE" BORDER="0" + SRC="img172.gif" + ALT="$\beta~(=H_0/r_0)$"> is + an adaption of expression 9 from Stone (1996). The + adaptations, arrived at empirically, consist of (i) a + small adjustment to the coefficient and (ii) a humidity + term for the radio case only. +<LI> The formulae for the refraction constants as a function of + <I>n</I>-1 and <IMG WIDTH="12" HEIGHT="27" ALIGN="MIDDLE" BORDER="0" + SRC="img173.gif" + ALT="$\beta$"> are from Green (1987), expression 4.31. + </UL></DL></DL> +<P> <DL> +<DT><STRONG>REFERENCES:</STRONG> +<DD><DL COMPACT> +<DT>1. +<DD>Crane, R.K., Meeks, M.L. (ed), ``Refraction Effects in +the Neutral Atmosphere'', +<I>Methods of Experimental Physics: Astrophysics 12B,</I> + Academic Press, 1976. + <DT>2. +<DD>Gill, Adrian E., <I>Atmosphere-Ocean Dynamics,</I> + Academic Press, 1982. + <DT>3. +<DD>Hohenkerk, C.Y., & Sinclair, A.T., NAO Technical Note + No. 63, 1985. + <DT>4. +<DD>International Geodesy Association General Assembly, Bulletin + Géodésique <B>70</B> p390, 1963. + <DT>5. +<DD>Stone, Ronald C., P.A.S.P. <B>108</B> 1051-1058, 1996. + <DT>6. +<DD>Green, R.M., <I>Spherical Astronomy,</I> Cambridge + University Press, 1987. + </DL></DL> +<BR> <HR> +<A NAME="tex2html2086" HREF="node167.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html2084" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html2078" HREF="node165.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="tex2html2087" HREF="node167.html">SLA_REFRO - Refraction</A> +<BR> +<B>Up:</B> <A NAME="tex2html2085" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html2079" HREF="node165.html">SLA_REFCO - Refraction Constants</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> |