/usr/share/doc/munipack/man_aphot.html is in munipack-doc 0.5.10-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 | <!DOCTYPE HTML>
<html lang="en">
<head>
<!-- meta -->
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="description" content="A general astronomical image processing software">
<meta name="author" content="Filip Hroch">
<link href="news_feed.xml" type="application/atom+xml" rel="alternate" title="Sitewide ATOM Feed" />
<link type="text/css" rel="stylesheet" href="munipack.css">
<link rel="shortcut icon" href="favicon.ico">
<title>Munipack ‒ Aperture Photometry</title>
</head>
<body>
<header>
<a href="munipack.html"><img src="title_logo.png" alt="Munipack's logo" class="head"></a>
<div class="headhead">
<div class="headtitle">
<a class="headtitle" href="munipack.html">Munipack</a>
<a class="headsubtitle" href="munipack.html">A general astronomical image processing software</a>
</div>
<ul class="menu">
<li class="menu">◈ <a href="docs.html" class="menu">Documents</a></li>
<li class="menu">☺ <a href="guide.html" class="menu">User guide</a></li>
</ul>
</div>
</header>
<h1>Aperture Photometry</h1>
<p class="abstract">
Aperture photometry determines sum of counts from a star in a set of
predefined apertures.
</p>
<h2>Synopsis</h2>
<code>
munipack aphot [.. parameters ..] file(s)[,result(s)]
</code>
<p>Running of photometry adds a HDU extensions to the original frame
as a table described in <a href="dataform_proc.html">Processing Format</a>.
<h2>Algorithm</h2>
<p>Aperture photometry is performed by the way:</p>
<ul>
<li>Read parameters (command-line and gain and LOBAD,HIBAD) and
list of detected stars (in FIND extension).
</li>
<li>
For every detected star, the sum inside of the specified apertures
as well as in sky determining ring is computed.
</li>
<li>
The mean background in the ring is computed.
</li>
<li>
The counts for all apertures are computed by subtracting of mean background.
</li>
</ul>
<p>The pixels near the border are approximated by only a fraction covering
the pixel inside.
</p>
<p>
By defaults, twelve apertures is used. Aperture radii are computed
as points of logarithmic spiral <i>r = r<sub>0</sub></i>exp <i>a φ</i>
with the initial radius <i>r<sub>0</sub>=2</i> and pitch angle 8.9073°
(to be compatible with DAOPHOT II).
</p>
<p>
For a correct determination of photometry errors, the camera-specific
parameters must by provided.
</p>
<p>
Strictly speaking, for further processing just one aperture is required.
The prepare of several apertures has profit in fast switching to another
aperture without needs to do photometry again. More apertures can be also
used in simultaneous use of ones for PSF of grow-curve photometry.
</p>
<p>
The results of aperture photometry are stored in columns of a newly created
APERPHOT extension.
</p>
<p>
The photometry is performed for all detected stars (all stars in FIND extension)
in all specified apertures. Sometimes it is impossible compute the sum,
the case is indicated by a negative value (-1).
Common situation are when the sum of counts with subtracted background
is negative (sky is polluted by a bright source, background has a fast gradient)
or the star is too near of border and summing pixels are out of area)
or a star is saturated.
</p>
<p>
The results of aperture photometry are stored to next PHOTOMETRY extension.
In the extension, the results in a selected aperture (by <samp>-s</samp>)
are selected. Just stars with valid (non-negative) values are presented here.
</p>
<h2>Input And Output</h2>
<p>
On input, list of frames containing the table with already detected stars is expected.
</p>
<p>
On output, tables with the aperture photometry and results from the selected column,
represented by FITS extension, is added to all input images.
</p>
<h2>Parameters</h2>
<dl>
<dt><samp>--apertures r1, r2, .. rmax</samp></dt><dd>define apertures radii (in pixels),
count and sizes are arbitrary, must be specified in increasing
order and separated by commas</dd>
<dt><samp>--ring ri,ro</samp></dt><dd> inner and outer sky ring radius in pixels,
the outer radius must be equal or bigger than the greater aperture
</dd>
</dl>
<p>See <a href="man_com.html">Common options</a> for input/output filenames.</p>
<h2>History</h2>
<p>
The routine is on base of original code of DAOPHOT II by P.B.Stetson
(has been forked from Midas's implementation at 1996). Some additional
enhancements has been done:
</p>
<ul>
<li>Robust estimators replaces the original estimators of mean with filtering.</li>
<li>All processing is done in memory (no disc buffering is used).</li>
<!--<li>Real numbers in double precision are implemented</li>-->
<li>The magnitude output has been abandoned.</li>
<li>FITS files for both input and output are used</li>
<li>Log format is changed.</li>
<li>Seldom bugs are corrected.</li>
<li>Code is updated for Fortran 90 and 95 (and perhaps above).</li>
</ul>
<h2>Examples</h2>
<p>
Run aperture photometry:
</p>
<code>
$ munipack aphot pleiades.fits
</code>
<p>
Select apertures and sky estimation by hand (as powers of 2):
</p>
<code>
$ munipack aphot --apertures 1,2,4,8,16,32 --ring 16,32 pleiades.fits
</code>
<h2>See Also</h2>
<p>
<a href="grow.html">Growth Curve Overview</a>,
<a href="man_find.html">Detect Stars</a>,
<a href="man_com.html">Common options</a>,
<a href="dataform_photometry.html">Photometry Format</a>.
</p>
<footer>
<div style="float:left; margin-left:2em;">
Copyright © 1997 – 2018
Filip Hroch (<a style="text-decoration: none" href="mailto:hroch@physics.muni.cz?Subject=Munipack" title="Author's Email">✉</a>), license <a href="http://www.gnu.org/licenses/gpl.html">GPLv3</a>.
</div>
<div style="float:right; margin-right:2em; margin-top:-0.2em;">
<a href="http://monteboo.blogspot.com/search/label/Munipack" title="Munipack on MonteBoo Blog"><img src="favicon-blogger.png" alt="Blogger"></a>
<a href="http://www.muni.cz/?lang=en" title="Masaryk University in Brno, Czech Republic"><img src="mu-logo.png" alt="Masaryk University"></a>
<a href="news_feed.xml" title="Munipack's Releases in Atom Syndication Format"><img src="Feed-icon.png" alt="Atom Feed"></a>
</div>
</footer>
</body>
</html>
|