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...@@ -70,11 +70,11 @@ In total, the telescope can accomodate up to 20 receivers. A number of additiona ...@@ -70,11 +70,11 @@ In total, the telescope can accomodate up to 20 receivers. A number of additiona
<tr class="row-odd"><td>Position</td> <tr class="row-odd"><td>Position</td>
<td>Pranu Sanguni, San Basilio, Sardinia</td> <td>Pranu Sanguni, San Basilio, Sardinia</td>
</tr> </tr>
<tr class="row-even"><td>Coordinates</td> <tr class="row-even"><td>Geodetic Coordinates</td>
<td>Lat 39° 29’ 34.93742” N; Long 9° 14’ 42.5764” E</td> <td>Lat 39° 29’ 34.93742” N; Long 9° 14’ 42.5764” E (WGS84)</td>
</tr> </tr>
<tr class="row-odd"><td>Optical configuration</td> <tr class="row-odd"><td>Optical configuration</td>
<td>Gregorian &amp; Beam Waveguide (BWG)</td> <td>Primary, Gregorian &amp; Beam Waveguide (BWG)</td>
</tr> </tr>
<tr class="row-even"><td>Primary mirror diameter</td> <tr class="row-even"><td>Primary mirror diameter</td>
<td>64 m</td> <td>64 m</td>
...@@ -86,7 +86,7 @@ In total, the telescope can accomodate up to 20 receivers. A number of additiona ...@@ -86,7 +86,7 @@ In total, the telescope can accomodate up to 20 receivers. A number of additiona
<td>primary f/D = 0.33; Gregorian f/D = 2.34; Beam waveguide (BWG) f/D = 1.8</td> <td>primary f/D = 0.33; Gregorian f/D = 2.34; Beam waveguide (BWG) f/D = 1.8</td>
</tr> </tr>
<tr class="row-odd"><td>Azimuth range</td> <tr class="row-odd"><td>Azimuth range</td>
<td>–90 – 450 degrees</td> <td>–90 to 450 degrees</td>
</tr> </tr>
<tr class="row-even"><td>Elevation range</td> <tr class="row-even"><td>Elevation range</td>
<td>5 – 90 degrees</td> <td>5 – 90 degrees</td>
...@@ -98,7 +98,7 @@ In total, the telescope can accomodate up to 20 receivers. A number of additiona ...@@ -98,7 +98,7 @@ In total, the telescope can accomodate up to 20 receivers. A number of additiona
<td>0.3 – 115 GHz</td> <td>0.3 – 115 GHz</td>
</tr> </tr>
<tr class="row-odd"><td>Primary surface accuracy</td> <tr class="row-odd"><td>Primary surface accuracy</td>
<td>65 μm rms</td> <td>300 μm rms</td>
</tr> </tr>
<tr class="row-even"><td>Pointing accuracy (rms)</td> <tr class="row-even"><td>Pointing accuracy (rms)</td>
<td>2 – 5”</td> <td>2 – 5”</td>
...@@ -106,7 +106,7 @@ In total, the telescope can accomodate up to 20 receivers. A number of additiona ...@@ -106,7 +106,7 @@ In total, the telescope can accomodate up to 20 receivers. A number of additiona
</tbody> </tbody>
</table> </table>
<p>Active surface</p> <p>Active surface</p>
<p>The primary reflector, which is 64 m across, is made of 1008 aluminium panels (with RMS ≤ 65 μm) driven by 1116 electromechanical actuators. This <em>active surface</em> <p>The primary reflector, which is 64 m across, is made of 1008 aluminium panels (with an RMS ≤ 65 μm each) driven by 1116 electromechanical actuators. This <em>active surface</em>
is designed to compensate for the gravitational deformations of the whole surface at different elevations.</p> is designed to compensate for the gravitational deformations of the whole surface at different elevations.</p>
<p>The observer can choose among three configurations:</p> <p>The observer can choose among three configurations:</p>
<ul class="simple"> <ul class="simple">
...@@ -151,13 +151,13 @@ Each receiver feed allows for two polarizations.</p> ...@@ -151,13 +151,13 @@ Each receiver feed allows for two polarizations.</p>
</thead> </thead>
<tbody valign="top"> <tbody valign="top">
<tr class="row-even"><td>P</td> <tr class="row-even"><td>P</td>
<td>0.305 – 0.410</td> <td>0.300 – 0.360</td>
<td>1</td> <td>1</td>
<td>linear</td> <td>linear</td>
<td>primary</td> <td>primary</td>
<td>56.2’</td> <td>56.2’</td>
<td>65?</td> <td>[50-80]</td>
<td>45?</td> <td>[45]</td>
<td>125</td> <td>125</td>
</tr> </tr>
<tr class="row-odd"><td>L</td> <tr class="row-odd"><td>L</td>
...@@ -166,8 +166,8 @@ Each receiver feed allows for two polarizations.</p> ...@@ -166,8 +166,8 @@ Each receiver feed allows for two polarizations.</p>
<td>linear</td> <td>linear</td>
<td>primary</td> <td>primary</td>
<td>12.6’</td> <td>12.6’</td>
<td>21?</td> <td>25-35</td>
<td>47?</td> <td>[47]</td>
<td>36</td> <td>36</td>
</tr> </tr>
<tr class="row-even"><td>C-high</td> <tr class="row-even"><td>C-high</td>
...@@ -176,7 +176,7 @@ Each receiver feed allows for two polarizations.</p> ...@@ -176,7 +176,7 @@ Each receiver feed allows for two polarizations.</p>
<td>circular</td> <td>circular</td>
<td>beam waveguide</td> <td>beam waveguide</td>
<td>2.8’</td> <td>2.8’</td>
<td>26(*)</td> <td>32-37(*)</td>
<td>48</td> <td>48</td>
<td>43(*)</td> <td>43(*)</td>
</tr> </tr>
...@@ -192,7 +192,8 @@ Each receiver feed allows for two polarizations.</p> ...@@ -192,7 +192,8 @@ Each receiver feed allows for two polarizations.</p>
</tr> </tr>
</tbody> </tbody>
</table> </table>
<p>(*) at 6.7 GHz <p>[ ] is an estimate
(*) at 6.7 GHz
(**) at 22.3 GHz with opacity 0.1 and ground air temperature of 293K.</p> (**) at 22.3 GHz with opacity 0.1 and ground air temperature of 293K.</p>
<p>The FWHM beam size, as a function of the frequency f, can be approximated by the following rule: FWHM(arcmin)=19.7/ f(GHz)</p> <p>The FWHM beam size, as a function of the frequency f, can be approximated by the following rule: FWHM(arcmin)=19.7/ f(GHz)</p>
<p>SRT receiver changes are quick, allowing for an efficient frequency agility. The selected receiver is set in its focal position within at most a few minutes.</p> <p>SRT receiver changes are quick, allowing for an efficient frequency agility. The selected receiver is set in its focal position within at most a few minutes.</p>
...@@ -202,14 +203,7 @@ Additionally, a number of high-energy receivers are being planned for the SRT. T ...@@ -202,14 +203,7 @@ Additionally, a number of high-energy receivers are being planned for the SRT. T
<div class="section" id="rf-filters"> <div class="section" id="rf-filters">
<h2>RF filters<a class="headerlink" href="#rf-filters" title="Permalink to this headline"></a></h2> <h2>RF filters<a class="headerlink" href="#rf-filters" title="Permalink to this headline"></a></h2>
<p>Different RF filters are available for the LP-band receiver. Although it is a coaxial receiver package, the control system sees it as a group of three different receivers, each one with its own code:</p> <p>Different RF filters are available for the LP-band receiver. Although it is a coaxial receiver package, the control system sees it as a group of three different receivers, each one with its own code:</p>
<p>For the PPP receiver (P-band), available filters are:</p> <p>For the PPP receiver (P-band), there is one available filter (L2): 300–360 MHz (needed to exclude RFI at higher frequencies).</p>
<blockquote>
<div><ol class="arabic simple">
<li>all band, 305–410 MHz (no filter)</li>
<li>310–350 MHz</li>
<li>305–410 MHz (band-pass filter, sharper band edges).</li>
</ol>
</div></blockquote>
<p>These are available for the LLP (L-band) configuration:</p> <p>These are available for the LLP (L-band) configuration:</p>
<blockquote> <blockquote>
<div><ol class="arabic simple"> <div><ol class="arabic simple">
...@@ -292,14 +286,14 @@ The observer can select the following configurations:</p> ...@@ -292,14 +286,14 @@ The observer can select the following configurations:</p>
</div> </div>
<div class="section" id="pulsar-digital-filter-bank-mark-3-pdfb3"> <div class="section" id="pulsar-digital-filter-bank-mark-3-pdfb3">
<h2>Pulsar Digital Filter Bank mark 3 (PDFB3)<a class="headerlink" href="#pulsar-digital-filter-bank-mark-3-pdfb3" title="Permalink to this headline"></a></h2> <h2>Pulsar Digital Filter Bank mark 3 (PDFB3)<a class="headerlink" href="#pulsar-digital-filter-bank-mark-3-pdfb3" title="Permalink to this headline"></a></h2>
<p>This is a FX correlator developed by the Australia Telescope National Facility (ATNF) that performs full-Stokes observations. It allows for four inputs, each with a 1024 MHz maximum bandwidth, and 8-bit sampling for a high dynamic range. The DFB3 is suitable for precise pulsar timing and searching, as well as spectral line and continuum observations with a high time resolution. It allows for up to 8192 spectral channels in order to counter the effects of interstellar dispersion when it is operated in pulsar mode, and for power spectrum measurements in spectrometer mode.</p> <p>This is an FX correlator developed by the Australia Telescope National Facility (ATNF) that performs full-Stokes observations. It allows for four inputs, each with a 1024 MHz maximum bandwidth and 8-bit sampling for a high dynamic range. The DFB3 is suitable for precise pulsar timing and searching. It allows for up to 8192 spectral channels in order to counter the effects of interstellar dispersion.</p>
<p>The main available configurations for pulsar observations are the following:</p> <p>The main available configurations for pulsar observations are the following:</p>
<table border="1" class="docutils"> <table border="1" class="docutils">
<colgroup> <colgroup>
<col width="17%" /> <col width="16%" />
<col width="23%" /> <col width="24%" />
<col width="28%" /> <col width="27%" />
<col width="32%" /> <col width="33%" />
</colgroup> </colgroup>
<thead valign="bottom"> <thead valign="bottom">
<tr class="row-odd"><th class="head">Obs type</th> <tr class="row-odd"><th class="head">Obs type</th>
...@@ -388,7 +382,7 @@ The observer can select the following configurations:</p> ...@@ -388,7 +382,7 @@ The observer can select the following configurations:</p>
</tbody> </tbody>
</table> </table>
<p>Further details about the DFB can be found in the ATNF <a class="reference external" href="http://www.srt.inaf.it/media/uploads/astronomers/dfb.pdf">DFB manual</a>.</p> <p>Further details about the DFB can be found in the ATNF <a class="reference external" href="http://www.srt.inaf.it/media/uploads/astronomers/dfb.pdf">DFB manual</a>.</p>
<p>At the SRT, DFB observations are piloted using the SEADAS software. For more information:</p> <p>At the SRT, DFB observations are piloted using the SEADAS software.</p>
<p>Additional, so-called <em>Maccaferri</em> filters are available at L-band at the level of the backends. The recommended filter for pulsar observations at L-band <p>Additional, so-called <em>Maccaferri</em> filters are available at L-band at the level of the backends. The recommended filter for pulsar observations at L-band
is the <em>WIDE</em> filter (460 MHz of bandwidth).</p> is the <em>WIDE</em> filter (460 MHz of bandwidth).</p>
</div> </div>
...@@ -402,10 +396,11 @@ is the <em>WIDE</em> filter (460 MHz of bandwidth).</p> ...@@ -402,10 +396,11 @@ is the <em>WIDE</em> filter (460 MHz of bandwidth).</p>
<p>SARDARA is a backend composed of seven fully-reconfigurable ROACH-2 boards that allow it to perform wide-band, full-Stokes observations. The many observing modes covered by SARDARA include: continuum, spectroscopy, spectro-polarimetry, as well as high-time resolution for pulsars and fast transients . Its sampling time can be set from 5ms to 1 s. It is the backend of choice for OTF spectro-polarimetric observations. <p>SARDARA is a backend composed of seven fully-reconfigurable ROACH-2 boards that allow it to perform wide-band, full-Stokes observations. The many observing modes covered by SARDARA include: continuum, spectroscopy, spectro-polarimetry, as well as high-time resolution for pulsars and fast transients . Its sampling time can be set from 5ms to 1 s. It is the backend of choice for OTF spectro-polarimetric observations.
Available configurations consist of:</p> Available configurations consist of:</p>
<ul class="simple"> <ul class="simple">
<li>300 MHz bandwith with 1024 or 16384 channels</li> <li>420 MHz bandwith with 1024 or 16384 channels</li>
<li>1500 MHz bandwidth with 1024 or 16384 channels</li> <li>1500 MHz bandwidth with 1024 or 16384 channels</li>
</ul> </ul>
<p>The 300 MHz configurations should only be used with the L-Band receiver and the following RF filters: (3) 1350 - 1450 MHz or (5) 1625 - 1715 MHz, in order to avoid aliasing.</p> <p>The 420 MHz configurations should only be used with the L-Band receiver and the following RF filters: (3) 1350 - 1450 MHz or (5) 1625 - 1715 MHz, in order to avoid aliasing.</p>
<p>SARDARA’s spectral resolution and sensitivity is defined by its full 1500 MHz bandwidth. However only 1200 MHz of the full 1500 MHz bandwidth is usable, since the 1200 MHz filter of the Total Power backend is being used as input to SARDARA.</p>
<p>More detailed information on the SARDARA backend can be found here: <a class="reference external" href="https://www.worldscientific.com/doi/full/10.1142/S2251171718500046">SARDARA</a>.</p> <p>More detailed information on the SARDARA backend can be found here: <a class="reference external" href="https://www.worldscientific.com/doi/full/10.1142/S2251171718500046">SARDARA</a>.</p>
</div> </div>
</div> </div>
...@@ -413,71 +408,53 @@ Available configurations consist of:</p> ...@@ -413,71 +408,53 @@ Available configurations consist of:</p>
<h1>Calibration<a class="headerlink" href="#calibration" title="Permalink to this headline"></a></h1> <h1>Calibration<a class="headerlink" href="#calibration" title="Permalink to this headline"></a></h1>
<div class="section" id="pointing-calibration"> <div class="section" id="pointing-calibration">
<h2>Pointing calibration<a class="headerlink" href="#pointing-calibration" title="Permalink to this headline"></a></h2> <h2>Pointing calibration<a class="headerlink" href="#pointing-calibration" title="Permalink to this headline"></a></h2>
<p>Pointing model: this procedure was used to calculate the pointing errors compared to ideal conditions, at night without sunlight. Actual conditions could
require pointing measurements to take into account possible errors due to environmental factors (pointing measurements can be included in the observation schedule).</p>
<ul class="simple"> <ul class="simple">
<li>C-band</li> <li>L-band</li>
</ul> </ul>
<table border="1" class="docutils"> <p>Values adopted same as Bolli et al (2015)</p>
<colgroup>
<col width="48%" />
<col width="52%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Parameter</th>
<th class="head">Value (deg)</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Az-mean</td>
<td>+0.000440</td>
</tr>
<tr class="row-odd"><td>Az-rms</td>
<td>+0.000790</td>
</tr>
<tr class="row-even"><td>El-mean</td>
<td>-0.001660</td>
</tr>
<tr class="row-odd"><td>El-rms</td>
<td>+0.000910</td>
</tr>
</tbody>
</table>
<p>Note: updated as of 2018</p>
<ul class="simple"> <ul class="simple">
<li>K-band</li> <li>C-band</li>
</ul> </ul>
<table border="1" class="docutils"> <table border="1" class="docutils">
<colgroup> <colgroup>
<col width="48%" /> <col width="19%" />
<col width="52%" /> <col width="41%" />
<col width="41%" />
</colgroup> </colgroup>
<thead valign="bottom"> <thead valign="bottom">
<tr class="row-odd"><th class="head">Parameter</th> <tr class="row-odd"><th class="head">Parameter</th>
<th class="head">Value (deg)</th> <th class="head">Value (deg) for C-band</th>
<th class="head">Value (deg) for K-band</th>
</tr> </tr>
</thead> </thead>
<tbody valign="top"> <tbody valign="top">
<tr class="row-even"><td>Az-mean</td> <tr class="row-even"><td>Az-mean</td>
<td>+0.000440</td>
<td>+0.000850</td> <td>+0.000850</td>
</tr> </tr>
<tr class="row-odd"><td>Az-rms</td> <tr class="row-odd"><td>Az-rms</td>
<td>+0.000790</td>
<td>+0.000870</td> <td>+0.000870</td>
</tr> </tr>
<tr class="row-even"><td>El-mean</td> <tr class="row-even"><td>El-mean</td>
<td>-0.001660</td>
<td>-0.001280</td> <td>-0.001280</td>
</tr> </tr>
<tr class="row-odd"><td>El-rms</td> <tr class="row-odd"><td>El-rms</td>
<td>+0.000910</td>
<td>+0.001200</td> <td>+0.001200</td>
</tr> </tr>
</tbody> </tbody>
</table> </table>
<p>Note: for K-band, we are keeping the Pointing Model derived in 2012 and used during the ESP (2016).</p>
</div> </div>
<div class="section" id="focus-curve-calibration"> <div class="section" id="focus-curve-calibration">
<h2>Focus curve calibration<a class="headerlink" href="#focus-curve-calibration" title="Permalink to this headline"></a></h2> <h2>Focus curve calibration<a class="headerlink" href="#focus-curve-calibration" title="Permalink to this headline"></a></h2>
<p>The focus curve is applied in real time.</p>
<ul class="simple"> <ul class="simple">
<li>C-band</li> <li>C-band</li>
</ul> </ul>
<p>Figure to attach</p>
<p>We fit the curve with a polynomial of degree 6, such as: y = a x^6+ b x^5 + c x^4 + d x^3 + e x^2 + f x + g</p> <p>We fit the curve with a polynomial of degree 6, such as: y = a x^6+ b x^5 + c x^4 + d x^3 + e x^2 + f x + g</p>
<table border="1" class="docutils"> <table border="1" class="docutils">
<colgroup> <colgroup>
...@@ -516,72 +493,51 @@ Available configurations consist of:</p> ...@@ -516,72 +493,51 @@ Available configurations consist of:</p>
<ul class="simple"> <ul class="simple">
<li>K-band</li> <li>K-band</li>
</ul> </ul>
<p>We derive the focus curve shown in the Figure below where, as a comparison, we report also the previous focus curve. We report an anomalous behaviour at elevations below 30° that cause severe defocusing.
For this reason, we decide to adopt the old focus curve.</p>
<p>Need table?</p>
</div> </div>
<div class="section" id="gain-curve-calibration"> <div class="section" id="gain-curve-calibration">
<h2>Gain curve calibration<a class="headerlink" href="#gain-curve-calibration" title="Permalink to this headline"></a></h2> <h2>Gain curve calibration<a class="headerlink" href="#gain-curve-calibration" title="Permalink to this headline"></a></h2>
<ul class="simple"> <ul class="simple">
<li>C-band</li> <li>L-band</li>
</ul> </ul>
<p>Plot of Gain (K/Jy) vs. El (degrees)</p> <p>Values adopted same as Bolli et al (2015)</p>
<table border="1" class="docutils">
<colgroup>
<col width="48%" />
<col width="52%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Parameter</th>
<th class="head">Value</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>C0</td>
<td>0.545439</td>
</tr>
<tr class="row-odd"><td>C1</td>
<td>0.00525597</td>
</tr>
<tr class="row-even"><td>C2</td>
<td>-4.55697e-5</td>
</tr>
</tbody>
</table>
<p>Time range valid from May 2018 until… 2017? 2016?</p>
<ul class="simple"> <ul class="simple">
<li>K-band</li> <li>C-band</li>
</ul> </ul>
<table border="1" class="docutils"> <table border="1" class="docutils">
<colgroup> <colgroup>
<col width="48%" /> <col width="28%" />
<col width="52%" /> <col width="36%" />
<col width="36%" />
</colgroup> </colgroup>
<thead valign="bottom"> <thead valign="bottom">
<tr class="row-odd"><th class="head">Parameter</th> <tr class="row-odd"><th class="head">Parameter</th>
<th class="head">Value</th> <th class="head">Value (C-band)</th>
<th class="head">Value (K-band)</th>
</tr> </tr>
</thead> </thead>
<tbody valign="top"> <tbody valign="top">
<tr class="row-even"><td>C0</td> <tr class="row-even"><td>C0</td>
<td>0.545439</td>
<td>0.505427</td> <td>0.505427</td>
</tr> </tr>
<tr class="row-odd"><td>C1</td> <tr class="row-odd"><td>C1</td>
<td>0.00525597</td>
<td>0.00864506</td> <td>0.00864506</td>
</tr> </tr>
<tr class="row-even"><td>C2</td> <tr class="row-even"><td>C2</td>
<td>-4.55697e-5</td>
<td>-6.37184e-5</td> <td>-6.37184e-5</td>
</tr> </tr>
</tbody> </tbody>
</table> </table>
<p>Due to an issue of misalignment of subscans we could not compute the gain curve from OTF maps. Therefore, as long as the problem is not resolved, we give as a reference the gain curves presented in Prandoni et al. (2017).</p> <p>C-band Time range valid from 2018.</p>
<p>K-band: from Prandoni et al. (2017).</p>
</div> </div>
<div class="section" id="beam-shape"> <div class="section" id="beam-shape">
<h2>Beam shape<a class="headerlink" href="#beam-shape" title="Permalink to this headline"></a></h2> <h2>Beam shape<a class="headerlink" href="#beam-shape" title="Permalink to this headline"></a></h2>
<ul class="simple"> <ul class="simple">
<li>C-band</li> <li>C-band</li>
</ul> </ul>
<p>The beam size and beam deformations in C-band are fully consistent with the measurements reported during the AV and the first commissioning.</p>
<table border="1" class="docutils"> <table border="1" class="docutils">
<colgroup> <colgroup>
<col width="42%" /> <col width="42%" />
...@@ -624,6 +580,33 @@ For this reason, we decide to adopt the old focus curve.</p> ...@@ -624,6 +580,33 @@ For this reason, we decide to adopt the old focus curve.</p>
<ul class="simple"> <ul class="simple">
<li>K-band</li> <li>K-band</li>
</ul> </ul>
<table border="1" class="docutils">
<colgroup>
<col width="42%" />
<col width="30%" />
<col width="28%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Elevation range (deg)</th>
<th class="head">Second lobe (%)</th>
<th class="head">Third lobe (%)</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>20-40</td>
<td>11</td>
<td>0.6</td>
</tr>
<tr class="row-odd"><td>40-60</td>
<td>4.9</td>
<td>0.5</td>
</tr>
<tr class="row-even"><td>60-80</td>
<td>3.4</td>
<td>0.5</td>
</tr>
</tbody>
</table>
</div> </div>
<div class="section" id="list-of-calibrators"> <div class="section" id="list-of-calibrators">
<h2>List of calibrators<a class="headerlink" href="#list-of-calibrators" title="Permalink to this headline"></a></h2> <h2>List of calibrators<a class="headerlink" href="#list-of-calibrators" title="Permalink to this headline"></a></h2>
...@@ -674,7 +657,7 @@ For this reason, we decide to adopt the old focus curve.</p> ...@@ -674,7 +657,7 @@ For this reason, we decide to adopt the old focus curve.</p>
<p>Scientific tests and applications for the SRT are described in the following scientific validation paper: <p>Scientific tests and applications for the SRT are described in the following scientific validation paper:
<a class="reference external" href="https://www.aanda.org/articles/aa/abs/2017/12/aa30243-16/aa30243-16.html">Prandoni et. al, A&amp;A 608, A40 (2017)</a>.</p> <a class="reference external" href="https://www.aanda.org/articles/aa/abs/2017/12/aa30243-16/aa30243-16.html">Prandoni et. al, A&amp;A 608, A40 (2017)</a>.</p>
<p>Science done with SRT during its early-science run (2016) with the various hardware and software described below can be found here: <a class="reference external" href="http://www.srt.inaf.it/astronomers/science_srt/">Science with SRT</a>.</p> <p>Science done with SRT during its early-science run (2016) with the various hardware and software described below can be found here: <a class="reference external" href="http://www.srt.inaf.it/astronomers/science_srt/">Science with SRT</a>.</p>
<p>Spectral-polarimetric techniques with SRT: ` Sardinia Radio Telescope wide-band spectral-polarimetric observations of the galaxy cluster 3C 129 &lt;<a class="reference external" href="https://arxiv.org/abs/1607.03636">https://arxiv.org/abs/1607.03636</a>&gt;`_.</p> <p>Spectral-polarimetric techniques with SRT: <a class="reference external" href="https://arxiv.org/abs/1607.03636">Sardinia Radio Telescope wide-band spectral-polarimetric observations of the galaxy cluster 3C 129</a>.</p>
</div> </div>
<div class="section" id="user-guide-and-observing-modes"> <div class="section" id="user-guide-and-observing-modes">
<h1>User guide and observing modes<a class="headerlink" href="#user-guide-and-observing-modes" title="Permalink to this headline"></a></h1> <h1>User guide and observing modes<a class="headerlink" href="#user-guide-and-observing-modes" title="Permalink to this headline"></a></h1>
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antenna.rst
+ 71
− 89
View file @ 6729f17a
...@@ -34,10 +34,10 @@ The antenna's main characheristics are: ...@@ -34,10 +34,10 @@ The antenna's main characheristics are:
* - Position * - Position
- Pranu Sanguni, San Basilio, Sardinia - Pranu Sanguni, San Basilio, Sardinia
* - Coordinates * - Geodetic Coordinates
- Lat 39° 29' 34.93742" N; Long 9° 14' 42.5764" E - Lat 39° 29' 34.93742" N; Long 9° 14' 42.5764" E (WGS84)
* - Optical configuration * - Optical configuration
- Gregorian & Beam Waveguide (BWG) - Primary, Gregorian & Beam Waveguide (BWG)
* - Primary mirror diameter * - Primary mirror diameter
- 64 m - 64 m
* - Subreflector diameter * - Subreflector diameter
...@@ -45,7 +45,7 @@ The antenna's main characheristics are: ...@@ -45,7 +45,7 @@ The antenna's main characheristics are:
* - Focal positions * - Focal positions
- primary f/D = 0.33; Gregorian f/D = 2.34; Beam waveguide (BWG) f/D = 1.8 - primary f/D = 0.33; Gregorian f/D = 2.34; Beam waveguide (BWG) f/D = 1.8
* - Azimuth range * - Azimuth range
- --90 -- 450 degrees - --90 to 450 degrees
* - Elevation range * - Elevation range
- 5 -- 90 degrees - 5 -- 90 degrees
* - Slew rate * - Slew rate
...@@ -53,13 +53,13 @@ The antenna's main characheristics are: ...@@ -53,13 +53,13 @@ The antenna's main characheristics are:
* - Frequency coverage * - Frequency coverage
- 0.3 -- 115 GHz - 0.3 -- 115 GHz
* - Primary surface accuracy * - Primary surface accuracy
- 65 μm rms - 300 μm rms
* - Pointing accuracy (rms) * - Pointing accuracy (rms)
- 2 -- 5" - 2 -- 5"
Active surface Active surface
The primary reflector, which is 64 m across, is made of 1008 aluminium panels (with RMS ≤ 65 μm) driven by 1116 electromechanical actuators. This *active surface* The primary reflector, which is 64 m across, is made of 1008 aluminium panels (with an RMS ≤ 65 μm each) driven by 1116 electromechanical actuators. This *active surface*
is designed to compensate for the gravitational deformations of the whole surface at different elevations. is designed to compensate for the gravitational deformations of the whole surface at different elevations.
The observer can choose among three configurations: The observer can choose among three configurations:
...@@ -85,12 +85,13 @@ Each receiver feed allows for two polarizations. ...@@ -85,12 +85,13 @@ Each receiver feed allows for two polarizations.
======== ========================= ======= ================= =============== ========= ========== ========== ========= ======== ========================= ======= ================= =============== ========= ========== ========== =========
Band Frequency coverage (GHz) Feeds Polarization type Focal position Beam size Tsys (K) Gain (%) Sefd (Jy) Band Frequency coverage (GHz) Feeds Polarization type Focal position Beam size Tsys (K) Gain (%) Sefd (Jy)
======== ========================= ======= ================= =============== ========= ========== ========== ========= ======== ========================= ======= ================= =============== ========= ========== ========== =========
P 0.305 -- 0.410 1 linear primary 56.2' 65? 45? 125 P 0.300 -- 0.360 1 linear primary 56.2' [50-80] [45] 125
L 1.3 -- 1.8 1 linear primary 12.6' 21? 47? 36 L 1.3 -- 1.8 1 linear primary 12.6' 25-35 [47] 36
C-high 5.7 -- 7.7 1 circular beam waveguide 2.8' 26(*) 48 43(*) C-high 5.7 -- 7.7 1 circular beam waveguide 2.8' 32-37(*) 48 43(*)
K 18 -- 26 7 circular gregorian 50" 90(**) 44 138(**) K 18 -- 26 7 circular gregorian 50" 90(**) 44 138(**)
======== ========================= ======= ================= =============== ========= ========== ========== ========= ======== ========================= ======= ================= =============== ========= ========== ========== =========
[ ] is an estimate
(*) at 6.7 GHz (*) at 6.7 GHz
(**) at 22.3 GHz with opacity 0.1 and ground air temperature of 293K. (**) at 22.3 GHz with opacity 0.1 and ground air temperature of 293K.
...@@ -108,11 +109,7 @@ RF filters ...@@ -108,11 +109,7 @@ RF filters
Different RF filters are available for the LP-band receiver. Although it is a coaxial receiver package, the control system sees it as a group of three different receivers, each one with its own code: Different RF filters are available for the LP-band receiver. Although it is a coaxial receiver package, the control system sees it as a group of three different receivers, each one with its own code:
For the PPP receiver (P-band), available filters are: For the PPP receiver (P-band), there is one available filter (L2): 300--360 MHz (needed to exclude RFI at higher frequencies).
1. all band, 305--410 MHz (no filter)
2. 310--350 MHz
3. 305--410 MHz (band-pass filter, sharper band edges).
These are available for the LLP (L-band) configuration: These are available for the LLP (L-band) configuration:
...@@ -168,32 +165,32 @@ This digital platform is based on a flexible architecture composed of four ADC b ...@@ -168,32 +165,32 @@ This digital platform is based on a flexible architecture composed of four ADC b
Pulsar Digital Filter Bank mark 3 (PDFB3) Pulsar Digital Filter Bank mark 3 (PDFB3)
----------------------------------------- -----------------------------------------
This is a FX correlator developed by the Australia Telescope National Facility (ATNF) that performs full-Stokes observations. It allows for four inputs, each with a 1024 MHz maximum bandwidth, and 8-bit sampling for a high dynamic range. The DFB3 is suitable for precise pulsar timing and searching, as well as spectral line and continuum observations with a high time resolution. It allows for up to 8192 spectral channels in order to counter the effects of interstellar dispersion when it is operated in pulsar mode, and for power spectrum measurements in spectrometer mode. This is an FX correlator developed by the Australia Telescope National Facility (ATNF) that performs full-Stokes observations. It allows for four inputs, each with a 1024 MHz maximum bandwidth and 8-bit sampling for a high dynamic range. The DFB3 is suitable for precise pulsar timing and searching. It allows for up to 8192 spectral channels in order to counter the effects of interstellar dispersion.
The main available configurations for pulsar observations are the following: The main available configurations for pulsar observations are the following:
========= ============ =============== ================= ========= ============= =============== ==================
Obs type N. time bins Bandwidth (MHz) N. frequency bins Obs type N. time bins Bandwidth (MHz) N. frequency bins
========= ============ =============== ================= ========= ============= =============== ==================
folding 1024 1024 2048 folding 1024 1024 2048
folding 1024 1024 1024 folding 1024 1024 1024
folding 1024 1024 512 folding 1024 1024 512
folding 1024 512 2048 folding 1024 512 2048
folding 1024 512 1024 folding 1024 512 1024
folding 1024 512 512 folding 1024 512 512
folding 512 1024 1024 folding 512 1024 1024
folding 512 512 1024 folding 512 512 1024
folding 512 512 512 folding 512 512 512
folding 512 256 512 folding 512 256 512
folding 256 256 2048 folding 256 256 2048
folding 256 256 1024 folding 256 256 1024
search 512 1024 search 512 1024
search 512 128 search 512 128
========= ============ =============== ================= ========= ============= =============== ==================
Further details about the DFB can be found in the ATNF `DFB manual <http://www.srt.inaf.it/media/uploads/astronomers/dfb.pdf>`_. Further details about the DFB can be found in the ATNF `DFB manual <http://www.srt.inaf.it/media/uploads/astronomers/dfb.pdf>`_.
At the SRT, DFB observations are piloted using the SEADAS software. For more information: At the SRT, DFB observations are piloted using the SEADAS software.
Additional, so-called *Maccaferri* filters are available at L-band at the level of the backends. The recommended filter for pulsar observations at L-band Additional, so-called *Maccaferri* filters are available at L-band at the level of the backends. The recommended filter for pulsar observations at L-band
is the *WIDE* filter (460 MHz of bandwidth). is the *WIDE* filter (460 MHz of bandwidth).
...@@ -212,10 +209,12 @@ SARDARA ...@@ -212,10 +209,12 @@ SARDARA
SARDARA is a backend composed of seven fully-reconfigurable ROACH-2 boards that allow it to perform wide-band, full-Stokes observations. The many observing modes covered by SARDARA include: continuum, spectroscopy, spectro-polarimetry, as well as high-time resolution for pulsars and fast transients . Its sampling time can be set from 5ms to 1 s. It is the backend of choice for OTF spectro-polarimetric observations. SARDARA is a backend composed of seven fully-reconfigurable ROACH-2 boards that allow it to perform wide-band, full-Stokes observations. The many observing modes covered by SARDARA include: continuum, spectroscopy, spectro-polarimetry, as well as high-time resolution for pulsars and fast transients . Its sampling time can be set from 5ms to 1 s. It is the backend of choice for OTF spectro-polarimetric observations.
Available configurations consist of: Available configurations consist of:
* 300 MHz bandwith with 1024 or 16384 channels * 420 MHz bandwith with 1024 or 16384 channels
* 1500 MHz bandwidth with 1024 or 16384 channels * 1500 MHz bandwidth with 1024 or 16384 channels
The 300 MHz configurations should only be used with the L-Band receiver and the following RF filters: (3) 1350 - 1450 MHz or (5) 1625 - 1715 MHz, in order to avoid aliasing. The 420 MHz configurations should only be used with the L-Band receiver and the following RF filters: (3) 1350 - 1450 MHz or (5) 1625 - 1715 MHz, in order to avoid aliasing.
SARDARA's spectral resolution and sensitivity is defined by its full 1500 MHz bandwidth. However only 1200 MHz of the full 1500 MHz bandwidth is usable, since the 1200 MHz filter of the Total Power backend is being used as input to SARDARA.
More detailed information on the SARDARA backend can be found here: `SARDARA <https://www.worldscientific.com/doi/full/10.1142/S2251171718500046>`_. More detailed information on the SARDARA backend can be found here: `SARDARA <https://www.worldscientific.com/doi/full/10.1142/S2251171718500046>`_.
...@@ -225,38 +224,30 @@ Calibration ...@@ -225,38 +224,30 @@ Calibration
Pointing calibration Pointing calibration
-------------------- --------------------
* C-band Pointing model: this procedure was used to calculate the pointing errors compared to ideal conditions, at night without sunlight. Actual conditions could
require pointing measurements to take into account possible errors due to environmental factors (pointing measurements can be included in the observation schedule).
========== =========== * L-band
Parameter Value (deg)
========== ===========
Az-mean +0.000440
Az-rms +0.000790
El-mean -0.001660
El-rms +0.000910
========== ===========
Note: updated as of 2018 Values adopted same as Bolli et al (2015)
* K-band
========== =========== * C-band
Parameter Value (deg)
========== ===========
Az-mean +0.000850
Az-rms +0.000870
El-mean -0.001280
El-rms +0.001200
========== ===========
Note: for K-band, we are keeping the Pointing Model derived in 2012 and used during the ESP (2016). ========== ====================== ======================
Parameter Value (deg) for C-band Value (deg) for K-band
========== ====================== ======================
Az-mean +0.000440 +0.000850
Az-rms +0.000790 +0.000870
El-mean -0.001660 -0.001280
El-rms +0.000910 +0.001200
========== ====================== ======================
Focus curve calibration Focus curve calibration
----------------------- -----------------------
* C-band The focus curve is applied in real time.
Figure to attach * C-band
We fit the curve with a polynomial of degree 6, such as: y = a x^6+ b x^5 + c x^4 + d x^3 + e x^2 + f x + g We fit the curve with a polynomial of degree 6, such as: y = a x^6+ b x^5 + c x^4 + d x^3 + e x^2 + f x + g
...@@ -274,47 +265,32 @@ g 91.5590595452 ...@@ -274,47 +265,32 @@ g 91.5590595452
* K-band * K-band
We derive the focus curve shown in the Figure below where, as a comparison, we report also the previous focus curve. We report an anomalous behaviour at elevations below 30° that cause severe defocusing.
For this reason, we decide to adopt the old focus curve.
Need table?
Gain curve calibration Gain curve calibration
---------------------- ----------------------
* C-band * L-band
Plot of Gain (K/Jy) vs. El (degrees) Values adopted same as Bolli et al (2015)
=========== ============ * C-band
Parameter Value
=========== ============
C0 0.545439
C1 0.00525597
C2 -4.55697e-5
=========== ============
Time range valid from May 2018 until... 2017? 2016? =========== ============== ==============
Parameter Value (C-band) Value (K-band)
=========== ============== ==============
C0 0.545439 0.505427
C1 0.00525597 0.00864506
C2 -4.55697e-5 -6.37184e-5
=========== ============== ==============
* K-band C-band Time range valid from 2018.
=========== ============ K-band: from Prandoni et al. (2017).
Parameter Value
=========== ============
C0 0.505427
C1 0.00864506
C2 -6.37184e-5
=========== ============
Due to an issue of misalignment of subscans we could not compute the gain curve from OTF maps. Therefore, as long as the problem is not resolved, we give as a reference the gain curves presented in Prandoni et al. (2017).
Beam shape Beam shape
---------- ----------
* C-band * C-band
The beam size and beam deformations in C-band are fully consistent with the measurements reported during the AV and the first commissioning.
===================== =============== ============== ===================== =============== ==============
Elevation range (deg) Second lobe (%) Third lobe (%) Elevation range (deg) Second lobe (%) Third lobe (%)
===================== =============== ============== ===================== =============== ==============
...@@ -328,7 +304,13 @@ Elevation range (deg) Second lobe (%) Third lobe (%) ...@@ -328,7 +304,13 @@ Elevation range (deg) Second lobe (%) Third lobe (%)
* K-band * K-band
===================== =============== ==============
Elevation range (deg) Second lobe (%) Third lobe (%)
===================== =============== ==============
20-40 11 0.6
40-60 4.9 0.5
60-80 3.4 0.5
===================== =============== ==============
List of calibrators List of calibrators
...@@ -362,7 +344,7 @@ Scientific tests and applications for the SRT are described in the following sci ...@@ -362,7 +344,7 @@ Scientific tests and applications for the SRT are described in the following sci
Science done with SRT during its early-science run (2016) with the various hardware and software described below can be found here: `Science with SRT <http://www.srt.inaf.it/astronomers/science_srt/>`_. Science done with SRT during its early-science run (2016) with the various hardware and software described below can be found here: `Science with SRT <http://www.srt.inaf.it/astronomers/science_srt/>`_.
Spectral-polarimetric techniques with SRT: ` Sardinia Radio Telescope wide-band spectral-polarimetric observations of the galaxy cluster 3C 129 <https://arxiv.org/abs/1607.03636>`_. Spectral-polarimetric techniques with SRT: `Sardinia Radio Telescope wide-band spectral-polarimetric observations of the galaxy cluster 3C 129 <https://arxiv.org/abs/1607.03636>`_.
User guide and observing modes User guide and observing modes
============================== ==============================
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