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 <front>
  <journal-meta>
   <journal-id journal-id-type="publisher-id">Solar-Terrestrial Physics</journal-id>
   <journal-title-group>
    <journal-title xml:lang="en">Solar-Terrestrial Physics</journal-title>
    <trans-title-group xml:lang="ru">
     <trans-title>Solar-Terrestrial Physics</trans-title>
    </trans-title-group>
   </journal-title-group>
   <issn publication-format="online">2500-0535</issn>
  </journal-meta>
  <article-meta>
   <article-id pub-id-type="publisher-id">24537</article-id>
   <article-id pub-id-type="doi">10.12737/stp-44201811</article-id>
   <article-categories>
    <subj-group subj-group-type="toc-heading" xml:lang="ru">
     <subject>Results of current research</subject>
    </subj-group>
    <subj-group subj-group-type="toc-heading" xml:lang="en">
     <subject>Results of current research</subject>
    </subj-group>
    <subj-group>
     <subject>Results of current research</subject>
    </subj-group>
   </article-categories>
   <title-group>
    <article-title xml:lang="en">Simulating Siberian Radioheliograph response to the quiet Sun</article-title>
    <trans-title-group xml:lang="ru">
     <trans-title>Simulating Siberian Radioheliograph response to the quiet Sun</trans-title>
    </trans-title-group>
   </title-group>
   <contrib-group content-type="authors">
    <contrib contrib-type="author">
     <contrib-id contrib-id-type="orcid">https://orcid.org/0009-0004-1651-1259</contrib-id>
     <name-alternatives>
      <name xml:lang="ru">
       <surname>Лесовой</surname>
       <given-names>Сергей Владимирович</given-names>
      </name>
      <name xml:lang="en">
       <surname>Lesovoi</surname>
       <given-names>Sergey Vladimirovich</given-names>
      </name>
     </name-alternatives>
     <email>lesovoi@iszf.irk.ru</email>
     <bio xml:lang="ru">
      <p>доктор физико-математических наук;</p>
     </bio>
     <bio xml:lang="en">
      <p>doctor of physical and mathematical sciences;</p>
     </bio>
     <xref ref-type="aff" rid="aff-1"/>
    </contrib>
    <contrib contrib-type="author">
     <name-alternatives>
      <name xml:lang="ru">
       <surname>Кобец</surname>
       <given-names>Вероника Сергеевна</given-names>
      </name>
      <name xml:lang="en">
       <surname>Kobets</surname>
       <given-names>Veronika Sergeevna</given-names>
      </name>
     </name-alternatives>
     <email>nikakobets@gmail.com</email>
     <xref ref-type="aff" rid="aff-2"/>
    </contrib>
   </contrib-group>
   <aff-alternatives id="aff-1">
    <aff>
     <institution xml:lang="ru">Институт солнечно-земной физики СО РАН</institution>
     <city>Иркутск</city>
     <country>Россия</country>
    </aff>
    <aff>
     <institution xml:lang="en">Institute of Solar-Terrestrial Physics SB RAS</institution>
     <city>Irkutsk</city>
     <country>Russian Federation</country>
    </aff>
   </aff-alternatives>
   <aff-alternatives id="aff-2">
    <aff>
     <institution xml:lang="ru">Институт солнечно-земной физики СО РАН</institution>
     <country>RU</country>
    </aff>
    <aff>
     <institution xml:lang="en">Institute of Solar-Terrestrial Physics SB RAS</institution>
     <country>RU</country>
    </aff>
   </aff-alternatives>
   <volume>4</volume>
   <issue>4</issue>
   <fpage>82</fpage>
   <lpage>87</lpage>
   <self-uri xlink:href="https://zh-szf.ru/en/nauka/article/24537/view">https://zh-szf.ru/en/nauka/article/24537/view</self-uri>
   <abstract xml:lang="ru">
    <p>The Siberian Radioheliograph (SRH) correlation plot is the time dependence of the sum of absolute values of complex correlations over all baselines. These plots are built for each operating frequency of SRH. The correlation is related not only to the spatial coherence of the incident microwave emission but also to antenna gains. That is why we have to consider real SRH antenna gains and shadowings. Correlation plots obtained by SRH are related to microwave flux density of the Sun and spatial features of microwave sources. Also the correlation plots show variability of SRH beam pattern in time with constant flux density and spatial structure of sources. The SRH beam pattern depends on position of the Sun with respect to SRH, which changes with time. This leads to variations of these plots, which can be confused, for example, with the quasi-harmonic oscillations of the microwave flux produced by sources located above sunspots. Because the solar disk is an extended source, the correlation plot variability is mostly due to the SRH response to the quiet Sun. The smaller is the microwave source, the smaller are the correlation plot variations caused by a change of the beam pattern. Relatively fast variations result from long baseline responses, so it is undesirable to exclude them from the plots. Moreover, the sensitivity of the plots is better when all baselines are taken in account. The impact of the correlation plot variations on the eruptive event response is especially strong because variations of microwave flux during such events are comparable with those of the correlation plots in magnitude and time. From the above it seems reasonable to simulate the SRH response to the quiet solar disk and correct the correlation plots.&#13;
In this work, we propose a method for simulating correlation plots, which allows us to correct their variations caused by time and frequency dependence of SRH response to the solar disk. The correlation plots are simulated either by summing all model antenna pair responses to the model solar disk or by summing the corresponding values of the solar disk visibility under the assumption that the visibility is ~J1(x)/x, where J1(x) is the Bessel function of the first kind. Also we consider the shadowing of antennas nearest to the center of the SRH antenna array.</p>
   </abstract>
   <trans-abstract xml:lang="en">
    <p>The Siberian Radioheliograph (SRH) correlation plot is the time dependence of the sum of absolute values of complex correlations over all baselines. These plots are built for each operating frequency of SRH. The correlation is related not only to the spatial coherence of the incident microwave emission but also to antenna gains. That is why we have to consider real SRH antenna gains and shadowings. Correlation plots obtained by SRH are related to microwave flux density of the Sun and spatial features of microwave sources. Also the correlation plots show variability of SRH beam pattern in time with constant flux density and spatial structure of sources. The SRH beam pattern depends on position of the Sun with respect to SRH, which changes with time. This leads to variations of these plots, which can be confused, for example, with the quasi-harmonic oscillations of the microwave flux produced by sources located above sunspots. Because the solar disk is an extended source, the correlation plot variability is mostly due to the SRH response to the quiet Sun. The smaller is the microwave source, the smaller are the correlation plot variations caused by a change of the beam pattern. Relatively fast variations result from long baseline responses, so it is undesirable to exclude them from the plots. Moreover, the sensitivity of the plots is better when all baselines are taken in account. The impact of the correlation plot variations on the eruptive event response is especially strong because variations of microwave flux during such events are comparable with those of the correlation plots in magnitude and time. From the above it seems reasonable to simulate the SRH response to the quiet solar disk and correct the correlation plots.&#13;
In this work, we propose a method for simulating correlation plots, which allows us to correct their variations caused by time and frequency dependence of SRH response to the solar disk. The correlation plots are simulated either by summing all model antenna pair responses to the model solar disk or by summing the corresponding values of the solar disk visibility under the assumption that the visibility is ~J1(x)/x, where J1(x) is the Bessel function of the first kind. Also we consider the shadowing of antennas nearest to the center of the SRH antenna array.</p>
   </trans-abstract>
   <kwd-group xml:lang="ru">
    <kwd>solar radio telescope</kwd>
    <kwd>visibility function</kwd>
    <kwd>correlation</kwd>
    <kwd>radio interferometer</kwd>
   </kwd-group>
   <kwd-group xml:lang="en">
    <kwd>solar radio telescope</kwd>
    <kwd>visibility function</kwd>
    <kwd>correlation</kwd>
    <kwd>radio interferometer</kwd>
   </kwd-group>
  </article-meta>
 </front>
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  <ref-list>
   <ref id="B1">
    <label>1.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Grechnev V.V., Lesovoi S.V., Smolkov G.Ya., Krissinel B.B., Zandanov V.G., Altyntsev A.T., Kardapolova N.N., Sergeev R.Y., Uralov A.M., Maksimov V.P., Lubyshev B.I. The Siberian Solar Radio Telescope: the current state of the instrument, observations, and data. Solar Phys. 2003, vol. 216, iss. 1, pp. 239-272. DOI: 10.1023/A:1026153410061.</mixed-citation>
     <mixed-citation xml:lang="en">Grechnev V.V., Lesovoi S.V., Smolkov G.Ya., Krissinel B.B., Zandanov V.G., Altyntsev A.T., Kardapolova N.N., Sergeev R.Y., Uralov A.M., Maksimov V.P., Lubyshev B.I. The Siberian Solar Radio Telescope: the current state of the instrument, observations, and data. Solar Phys. 2003, vol. 216, iss. 1, pp. 239-272. DOI: 10.1023/A:1026153410061.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B2">
    <label>2.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Knizhnik K.J., Uritsky V.M., Klimchuk J.A., DeVore C.R. Power-law statistics of driven reconnection in the magnetically closed corona. Astrophys. J. 2018, vol. 853, iss. 1, article id. 82, 14 p. DOI: 10.3847/1538-4357/aaa0d9.</mixed-citation>
     <mixed-citation xml:lang="en">Knizhnik K.J., Uritsky V.M., Klimchuk J.A., DeVore C.R. Power-law statistics of driven reconnection in the magnetically closed corona. Astrophys. J. 2018, vol. 853, iss. 1, article id. 82, 14 p. DOI: 10.3847/1538-4357/aaa0d9.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B3">
    <label>3.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Lesovoi S.V., Kobets V. Correlation plots of the Siberian Radioheliograph. Solar-Terr. Phys. 2017, vol. 3, iss. 1, pp. 19-25. DOI: 10.12737/article58f96eeb8fa318.06122835.</mixed-citation>
     <mixed-citation xml:lang="en">Lesovoi S.V., Kobets V. Correlation plots of the Siberian Radioheliograph. Solar-Terr. Phys. 2017, vol. 3, iss. 1, pp. 19-25. DOI: 10.12737/article58f96eeb8fa318.06122835.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B4">
    <label>4.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Lesovoi S.V., Altyntsev A.T., Ivanov E.F. Gubin A.V. The Multifrequency Siberian Radioheliograph. Solar Phys. 2012, vol. 280, iss. 2, pp. 651-661. DOI: 10.1007/s11207-012-0008-7.</mixed-citation>
     <mixed-citation xml:lang="en">Lesovoi S.V., Altyntsev A.T., Ivanov E.F. Gubin A.V. The Multifrequency Siberian Radioheliograph. Solar Phys. 2012, vol. 280, iss. 2, pp. 651-661. DOI: 10.1007/s11207-012-0008-7.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B5">
    <label>5.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Lesovoi S.V., Altyntsev A.T., Kochanov A.A., Grechnev V.V., Gubin A.V., Zhdanov D.A., Ivanov E.F., Uralov A.M., Kashapova L.K., Kuznetsov A.A., Meshalkina N.S., Sych R.F. Siberian Radioheliograph: first results. Solar-Terr. Phys. 2017, vol. 3, iss. 1, pp. 3-18. DOI: 10.12737/article_58f96ec60fec52. 86165286.</mixed-citation>
     <mixed-citation xml:lang="en">Lesovoi S.V., Altyntsev A.T., Kochanov A.A., Grechnev V.V., Gubin A.V., Zhdanov D.A., Ivanov E.F., Uralov A.M., Kashapova L.K., Kuznetsov A.A., Meshalkina N.S., Sych R.F. Siberian Radioheliograph: first results. Solar-Terr. Phys. 2017, vol. 3, iss. 1, pp. 3-18. DOI: 10.12737/article_58f96ec60fec52. 86165286.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B6">
    <label>6.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Parker E.N. Nanoflares and the solar X-ray corona. Astrophys. J. 1988, vol. 330, p. 474. DOI: 10.1086/166485.</mixed-citation>
     <mixed-citation xml:lang="en">Parker E.N. Nanoflares and the solar X-ray corona. Astrophys. J. 1988, vol. 330, p. 474. DOI: 10.1086/166485.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B7">
    <label>7.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Tompson A.R., Moran J.M., Svenson J.U. Interferometriya i sintez v radioastronomii [Interferometry and Synthesis in Radio Astronomy]. Moscow, Fizmatlit Publ., 2003. 624 p. (In Russian). English edition: Thompson A.R., Moran J.M., Swenson G.W. Interferometry and Syntnesis in Radio Astronomy: 2nd edition. Willey-VCH Publ., 2001, 715 p.</mixed-citation>
     <mixed-citation xml:lang="en">Tompson A.R., Moran J.M., Svenson J.U. Interferometriya i sintez v radioastronomii [Interferometry and Synthesis in Radio Astronomy]. Moscow, Fizmatlit Publ., 2003. 624 p. (In Russian). English edition: Thompson A.R., Moran J.M., Swenson G.W. Interferometry and Syntnesis in Radio Astronomy: 2nd edition. Willey-VCH Publ., 2001, 715 p.</mixed-citation>
    </citation-alternatives>
   </ref>
  </ref-list>
 </back>
</article>
