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author Daniele Nicolodi <nicolodi@science.unitn.it>
date Wed, 23 Nov 2011 19:22:13 +0100
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11 <title>IFO/Temperature Example - Introduction (LTPDA Toolbox)</title>
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15 "Presents an overview of the features, system requirements, and starting the toolbox.">
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20
21 <p style="font-size:1px;">&nbsp;</p>
22
23 <table class="nav" summary="Navigation aid" border="0" width=
24 "100%" cellpadding="0" cellspacing="0">
25 <tr>
26 <td valign="baseline"><b>LTPDA Toolbox</b></td><td><a href="../helptoc.html">contents</a></td>
27
28 <td valign="baseline" align="right"><a href=
29 "ltpda_training_topic_1_7.html"><img src="b_prev.gif" border="0" align=
30 "bottom" alt="Writing LTPDA scripts"></a>&nbsp;&nbsp;&nbsp;<a href=
31 "ltpda_training_topic_2.html"><img src="b_next.gif" border="0" align=
32 "bottom" alt="Topic 2 - Pre-processing of data"></a></td>
33 </tr>
34 </table>
35
36 <h1 class="title"><a name="f3-12899" id="f3-12899"></a>IFO/Temperature Example - Introduction</h1>
37 <hr>
38
39 <p>
40 <p>
41 In your data pack, you will find two raw data series. These are real measurements
42 of a system that looks like
43 </p>
44 <img src="images/ltpda_training_1/ifo_temp_model.png" alt="Model of the IFO/temperature system" width="600px" border="1">
45 <p>
46 We have measured the two signals, <tt>T(t)</tt> and <tt>X(t)</tt>. The displacement input to the
47 interferometer, <tt>dx(t)</tt>, is inaccessible to us, and is in fact the data we want to
48 recover from the data analysis.
49 </p>
50 <br>
51 <br>
52 <h2>Reading and calibrating the interferometer data</h2>
53 <br>
54 <p>
55 The interferometer data, X(t), is saved in the file <tt>ifo_temp_example/ifo_training.dat</tt>. This is a
56 two-column ASCII file with the first column giving the time-stamps of the data and the second column the
57 measured IFO output in radians.
58 </p>
59 <p>
60 To read in the data, we can use the AO constuctor, with the set of parameters "From ASCII File". The key
61 parameters are:
62 <table cellspacing="0" class="body" cellpadding="2" border="0" width="80%">
63 <colgroup>
64 <col width="15%"/>
65 <col width="35%"/>
66 <col width="50%"/>
67 </colgroup>
68 <thead>
69 <tr valign="top">
70 <th class="categorylist">Key</th>
71 <th class="categorylist">Value</th>
72 <th class="categorylist">Description</th>
73 </tr>
74 </thead>
75 <tbody>
76 <!-- Key 'filename' -->
77 <tr valign="top">
78 <td bgcolor="#f3f4f5">
79 <p><tt>FILENAME</tt></p>
80 </td>
81 <td bgcolor="#f3f4f5">
82 <p><span class="string">'ifo_temp_example/ifo_training.dat'</span></p>
83 </td>
84 <td bgcolor="#f3f4f5">
85 <p>The name of the file to read the data from.</p>
86 </td>
87 </tr>
88 <!-- Key 'type' -->
89 <tr valign="top">
90 <td bgcolor="#f3f4f5">
91 <p><tt>TYPE</tt></p>
92 </td>
93 <td bgcolor="#f3f4f5">
94 <p><span class="string">'tsdata'</span></p>
95 </td>
96 <td bgcolor="#f3f4f5">
97 <p>Interpret the data in the file as time-series data.</p>
98 </td>
99 </tr>
100 <!-- Key 'columns' -->
101 <tr valign="top">
102 <td bgcolor="#f3f4f5">
103 <p><tt>COLUMNS</tt></p>
104 </td>
105 <td bgcolor="#f3f4f5">
106 <p>[1 2]</p>
107 </td>
108 <td bgcolor="#f3f4f5">
109 <p>Load the data x-y pairs from columns 1 (as x) and 2 (as y).</p>
110 </td>
111 </tr>
112 <!-- Key 'xunits' -->
113 <tr valign="top">
114 <td bgcolor="#f3f4f5">
115 <p><tt>XUNITS</tt></p>
116 </td>
117 <td bgcolor="#f3f4f5">
118 <p><span class="string">'s'</span></p>
119 </td>
120 <td bgcolor="#f3f4f5">
121 <p>Set the units of the x-data to seconds (s).</p>
122 </td>
123 </tr>
124 <!-- Key 'yunits' -->
125 <tr valign="top">
126 <td bgcolor="#f3f4f5">
127 <p><tt>YUNITS</tt></p>
128 </td>
129 <td bgcolor="#f3f4f5">
130 <p><span class="string">'rad'</span></p>
131 </td>
132 <td bgcolor="#f3f4f5">
133 <p>Set the units of the y-data to radians (rad).</p>
134 </td>
135 </tr>
136 <!-- Key 'robust' -->
137 <tr valign="top">
138 <td bgcolor="#f3f4f5">
139 <p><tt>ROBUST</tt></p>
140 </td>
141 <td bgcolor="#f3f4f5">
142 <p><span class="string">'no'</span></p>
143 </td>
144 <td bgcolor="#f3f4f5">
145 <p>Use fast data reading for this simple file format.</p>
146 </td>
147 </tr>
148 <!-- Key 'description' -->
149 <tr valign="top">
150 <td bgcolor="#f3f4f5">
151 <p><tt>DESCRIPTION</tt></p>
152 </td>
153 <td bgcolor="#f3f4f5">
154 <p><span class="string">'Interferometer data'</span></p>
155 </td>
156 <td bgcolor="#f3f4f5">
157 <p>Set some text to the 'description' field of the AO.</p>
158 </td>
159 </tr>
160 </tbody>
161 </table>
162 </p>
163 <p>
164 Once we've loaded the data we can calibrate it to displacement using the following
165 equation:
166 </p>
167 <img src="images/ltpda_training_1/topic1/ifo_cal_factor.png" alt="Convert rad to m" width="200px" border="1">
168 <p>
169
170 where lambda=1064nm.
171 </p>
172 <p>
173 To do the calibration, you can use the method <tt>ao/scale</tt>,
174 specifying the <tt>factor</tt> and the <tt>yunits</tt> of the factor
175 itself. Then save the resulting time-series to disk in <tt>ifo_temp_example/ifo_disp.xml</tt>.
176 </p>
177 <p>
178 A finished pipeline might look something like:
179 </p>
180 <img src="images/ltpda_training_1/topic1/ifo_cal_pipeline.png" alt="IFO calibration pipeline" border="1">
181
182
183 <br>
184 <br>
185 <h2>Reading and calibrating the temperature data</h2>
186 <br>
187 <p>
188 The temperature data, T(t), is saved in the file <tt>ifo_temp_example/temp_training.dat</tt>. Again, this is a
189 two-column ASCII file; the first column contains the time-stamps of the data, the second column
190 contains the temperature values in degrees Celsius.
191 </p>
192 <p>
193 To read in the data, we can use the AO constuctor, with the set of parameters "From ASCII File". The key
194 parameters are:
195 <table cellspacing="0" class="body" cellpadding="2" border="0" width="80%">
196 <colgroup>
197 <col width="15%"/>
198 <col width="35%"/>
199 <col width="50%"/>
200 </colgroup>
201 <thead>
202 <tr valign="top">
203 <th class="categorylist">Key</th>
204 <th class="categorylist">Value</th>
205 <th class="categorylist">Description</th>
206 </tr>
207 </thead>
208 <tbody>
209 <!-- Key 'filename' -->
210 <tr valign="top">
211 <td bgcolor="#f3f4f5">
212 <p><tt>FILENAME</tt></p>
213 </td>
214 <td bgcolor="#f3f4f5">
215 <p><span class="string">'ifo_temp_example/temp_training.dat'</span></p>
216 </td>
217 <td bgcolor="#f3f4f5">
218 <p>The name of the file to read the data from.</p>
219 </td>
220 </tr>
221 <!-- Key 'type' -->
222 <tr valign="top">
223 <td bgcolor="#f3f4f5">
224 <p><tt>TYPE</tt></p>
225 </td>
226 <td bgcolor="#f3f4f5">
227 <p><span class="string">'tsdata'</span></p>
228 </td>
229 <td bgcolor="#f3f4f5">
230 <p>Interpret the data in the file as time-series data.</p>
231 </td>
232 </tr>
233 <!-- Key 'columns' -->
234 <tr valign="top">
235 <td bgcolor="#f3f4f5">
236 <p><tt>COLUMNS</tt></p>
237 </td>
238 <td bgcolor="#f3f4f5">
239 <p>[1 2]</p>
240 </td>
241 <td bgcolor="#f3f4f5">
242 <p>Load the data x-y pairs from columns 1 (as x) and 2 (as y).</p>
243 </td>
244 </tr>
245 <!-- Key 'xunits' -->
246 <tr valign="top">
247 <td bgcolor="#f3f4f5">
248 <p><tt>XUNITS</tt></p>
249 </td>
250 <td bgcolor="#f3f4f5">
251 <p><span class="string">'s'</span></p>
252 </td>
253 <td bgcolor="#f3f4f5">
254 <p>Set the units of the x-data to seconds (s).</p>
255 </td>
256 </tr>
257 <!-- Key 'yunits' -->
258 <tr valign="top">
259 <td bgcolor="#f3f4f5">
260 <p><tt>YUNITS</tt></p>
261 </td>
262 <td bgcolor="#f3f4f5">
263 <p><span class="string">'degC'</span></p>
264 </td>
265 <td bgcolor="#f3f4f5">
266 <p>Set the units of the y-data to degrees Celsius.</p>
267 </td>
268 </tr>
269 <!-- Key 'robust' -->
270 <tr valign="top">
271 <td bgcolor="#f3f4f5">
272 <p><tt>ROBUST</tt></p>
273 </td>
274 <td bgcolor="#f3f4f5">
275 <p><span class="string">'no'</span></p>
276 </td>
277 <td bgcolor="#f3f4f5">
278 <p>Use fast data reading for this simple file format.</p>
279 </td>
280 </tr>
281 <!-- Key 'description' -->
282 <tr valign="top">
283 <td bgcolor="#f3f4f5">
284 <p><tt>DESCRIPTION</tt></p>
285 </td>
286 <td bgcolor="#f3f4f5">
287 <p><span class="string">'Temperature data'</span></p>
288 </td>
289 <td bgcolor="#f3f4f5">
290 <p>Set some text to the 'description' field of the AO.</p>
291 </td>
292 </tr>
293 </tbody>
294 </table>
295 </p>
296 <p>
297 Having loaded the temperature data, we can proceed to calibrate it to Kelvin by adding
298 273.15 to the data and then change the y-units. You can do this using the two AO methods:
299 <br>
300 <ul>
301 <li><tt>offset</tt> -- to add the offset</li>
302 <li><tt>setYunits</tt> -- to change the y-units of the data</li>
303 </ul>
304 </p>
305 <p>
306 The final step is to save this calibrated temperature data to disk as an AO XML file called
307 <tt>ifo_temp_example/temp_kelvin.xml</tt>, ready for input to the next topic.
308 </p>
309 <p>
310 A complete pipeline for this step might look like:
311 </p>
312 <img src="images/ltpda_training_1/topic1/temp_cal_pipeline.png" alt="Calibration pipeline for temperature data" border="1">
313 <p>
314 <table cellspacing="0" class="note" summary="Note" cellpadding="5" border="1">
315 <tr width="90%">
316 <td>
317 To plot the data with hours on the x-axis instead of seconds, use the <tt>iplot</tt> parameter <tt>XUNITS</tt>.
318 For example:
319 <div class="fragment"><pre>
320 iplot(a, plist(<span class="string">'XUNITS'</span>, <span class="string">'h'</span>))
321 </pre></div>
322 </td>
323 </tr>
324 </table>
325 </p>
326
327 </p>
328
329 <br>
330 <br>
331 <table class="nav" summary="Navigation aid" border="0" width=
332 "100%" cellpadding="0" cellspacing="0">
333 <tr valign="top">
334 <td align="left" width="20"><a href="ltpda_training_topic_1_7.html"><img src=
335 "b_prev.gif" border="0" align="bottom" alt=
336 "Writing LTPDA scripts"></a>&nbsp;</td>
337
338 <td align="left">Writing LTPDA scripts</td>
339
340 <td>&nbsp;</td>
341
342 <td align="right">Topic 2 - Pre-processing of data</td>
343
344 <td align="right" width="20"><a href=
345 "ltpda_training_topic_2.html"><img src="b_next.gif" border="0" align=
346 "bottom" alt="Topic 2 - Pre-processing of data"></a></td>
347 </tr>
348 </table><br>
349
350 <p class="copy">&copy;LTP Team</p>
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352 </html>