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| author | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-03-04 21:21:30 -0500 |
|---|---|---|
| committer | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-03-04 21:21:30 -0500 |
| commit | d54fe7c1f704a63824c5bfa0ece65245572e9b27 (patch) | |
| tree | afc52015ffc2c74e0266653eecef1c8ef8ba5d91 /src/slalib/sun67.htx/node24.html | |
| download | calfuse-d54fe7c1f704a63824c5bfa0ece65245572e9b27.tar.gz | |
Initial commit
Diffstat (limited to 'src/slalib/sun67.htx/node24.html')
| -rw-r--r-- | src/slalib/sun67.htx/node24.html | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/slalib/sun67.htx/node24.html b/src/slalib/sun67.htx/node24.html new file mode 100644 index 0000000..aecbb98 --- /dev/null +++ b/src/slalib/sun67.htx/node24.html @@ -0,0 +1,213 @@ +<!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_ATMDSP - Atmospheric Dispersion</TITLE> +<META NAME="description" CONTENT="SLA_ATMDSP - Atmospheric Dispersion"> +<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="node25.html"> +<LINK REL="previous" HREF="node23.html"> +<LINK REL="up" HREF="node13.html"> +<LINK REL="next" HREF="node25.html"> +</HEAD> +<BODY > +<BR> <HR> +<A NAME="tex2html666" HREF="node25.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html664" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html658" HREF="node23.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="tex2html667" HREF="node25.html">SLA_AV2M - Rotation Matrix from Axial Vector</A> +<BR> +<B>Up:</B> <A NAME="tex2html665" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html659" HREF="node23.html">SLA_AOPQK - Quick Appt-to-Observed</A> +<BR> <HR> <P> +<P><!--End of Navigation Panel--> +<H2><A NAME="SECTION000411000000000000000">SLA_ATMDSP - Atmospheric Dispersion</A> +<A NAME="xref_SLA_ATMDSP"> </A><A NAME="SLA_ATMDSP"> </A> +</H2> + <DL> +<DT><STRONG>ACTION:</STRONG> +<DD>Apply atmospheric-dispersion adjustments to refraction coefficients. +<DT><STRONG>CALL:</STRONG> +<DD><TT>CALL sla_ATMDSP (TDK, PMB, RH, WL1, A1, B1, WL2, A2, B2)</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>WL1</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>base wavelength (<IMG WIDTH="26" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img21.gif" + ALT="$\mu{\rm m}$">)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>A1</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>refraction coefficient A for wavelength WL1 (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>B1</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>refraction coefficient B for wavelength WL1 (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>WL2</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>wavelength for which adjusted A,B required (<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>A2</EM></TD> +<TH ALIGN="LEFT"><B>D</B></TH> +<TD ALIGN="LEFT" NOWRAP>refraction coefficient A for wavelength WL2 (radians)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="LEFT"><EM>B2</EM></TD> +<TD ALIGN="LEFT"><B>D</B></TD> +<TD ALIGN="LEFT" NOWRAP>refraction coefficient B for wavelength WL2 (radians)</TD> +</TR> +</TABLE></DL> +<P> <DL> +<DT><STRONG>NOTES:</STRONG> +<DD><DL COMPACT> +<DT>1. +<DD>To use this routine, first call sla_REFCO specifying WL1 as the +wavelength. This yields refraction coefficients A1, B1, correct +for that wavelength. Subsequently, calls to sla_ATMDSP specifying + different wavelengths will produce new, slightly adjusted + refraction coefficients A2, B2, which apply to the specified wavelength. + <DT>2. +<DD>Most of the atmospheric dispersion happens between <IMG WIDTH="50" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img34.gif" + ALT="$0.7\,\mu{\rm m}$"> and the UV atmospheric cutoff, and the effect increases strongly + towards the UV end. For this reason a blue reference wavelength + is recommended, for example <IMG WIDTH="50" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img35.gif" + ALT="$0.4\,\mu{\rm m}$">. <DT>3. +<DD>The accuracy, for this set of conditions: <BR> +<BR> + <TABLE CELLPADDING=3> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>height above sea level</TD> +<TD ALIGN="CENTER" NOWRAP> </TD> +<TD ALIGN="LEFT" NOWRAP>2000m</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>latitude</TD> +<TD ALIGN="CENTER" NOWRAP> </TD> +<TD ALIGN="LEFT" NOWRAP><IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img36.gif" + ALT="$29^\circ$"></TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>pressure</TD> +<TD ALIGN="CENTER" NOWRAP> </TD> +<TD ALIGN="LEFT" NOWRAP>793mB</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>temperature</TD> +<TD ALIGN="CENTER" NOWRAP> </TD> +<TD ALIGN="LEFT" NOWRAP><IMG WIDTH="34" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img37.gif" + ALT="$290^\circ$">K</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>humidity</TD> +<TD ALIGN="CENTER" NOWRAP> </TD> +<TD ALIGN="LEFT" NOWRAP>0.5 (50%)</TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>lapse rate</TD> +<TD ALIGN="CENTER" NOWRAP> </TD> +<TD ALIGN="LEFT" NOWRAP><IMG WIDTH="86" HEIGHT="17" ALIGN="BOTTOM" BORDER="0" + SRC="img38.gif" + ALT="$0.0065^\circ m^{-1}$"></TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>reference wavelength</TD> +<TD ALIGN="CENTER" NOWRAP> </TD> +<TD ALIGN="LEFT" NOWRAP><IMG WIDTH="50" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img35.gif" + ALT="$0.4\,\mu{\rm m}$"></TD> +</TR> +<TR VALIGN="TOP"><TD ALIGN="RIGHT" NOWRAP>star elevation</TD> +<TD ALIGN="CENTER" NOWRAP> </TD> +<TD ALIGN="LEFT" NOWRAP><IMG WIDTH="26" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" + SRC="img39.gif" + ALT="$15^\circ$"></TD> +</TR> +</TABLE> +<BR> +<BR> +is about 2.5mas RMS between 0.3 and <IMG WIDTH="50" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img40.gif" + ALT="$1.0\,\mu{\rm m}$">, and stays + within 4mas for the whole range longward of <IMG WIDTH="50" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img41.gif" + ALT="$0.3\,\mu{\rm m}$"> (compared with a total dispersion from 0.3 to <IMG WIDTH="45" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img42.gif" + ALT="$20\,\mu{\rm m}$"> of about <IMG WIDTH="25" HEIGHT="17" ALIGN="BOTTOM" BORDER="0" + SRC="img43.gif" + ALT="$11\hspace{-0.05em}^{'\hspace{-0.1em}'}$">). These errors are typical for ordinary + conditions; in extreme conditions values a few times this size + may occur. + <DT>4. +<DD>If either wavelength exceeds <IMG WIDTH="53" HEIGHT="25" ALIGN="MIDDLE" BORDER="0" + SRC="img44.gif" + ALT="$100\,\mu{\rm m}$">, the radio case + is assumed and the returned refraction coefficients are the + same as the given ones. + <DT>5. +<DD>The algorithm consists of calculation of the refractivity of the + air at the observer for the two wavelengths, using the methods + of the sla_REFRO routine, and then scaling of the two refraction + coefficients according to classical refraction theory. This + amounts to scaling the A coefficient in proportion to <IMG WIDTH="53" HEIGHT="29" ALIGN="MIDDLE" BORDER="0" + SRC="img45.gif" + ALT="$(\mu-1)$"> and + the B coefficient almost in the same ratio (see R.M.Green, + <I>Spherical Astronomy,</I> Cambridge University Press, 1985). + </DL></DL> +<BR> <HR> +<A NAME="tex2html666" HREF="node25.html"> +<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next_motif.gif"></A> +<A NAME="tex2html664" HREF="node13.html"> +<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up_motif.gif"></A> +<A NAME="tex2html658" HREF="node23.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="tex2html667" HREF="node25.html">SLA_AV2M - Rotation Matrix from Axial Vector</A> +<BR> +<B>Up:</B> <A NAME="tex2html665" HREF="node13.html">SUBPROGRAM SPECIFICATIONS</A> +<BR> +<B> Previous:</B> <A NAME="tex2html659" HREF="node23.html">SLA_AOPQK - Quick Appt-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> |