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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">100187</article-id>
   <article-id pub-id-type="doi">10.12737/stp-112202503</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">Data-driven approach to mid-latitude coherent scatter radar data classification</article-title>
    <trans-title-group xml:lang="ru">
     <trans-title>Data-driven approach to mid-latitude coherent scatter radar data classification</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/0000-0002-3837-8207</contrib-id>
     <name-alternatives>
      <name xml:lang="ru">
       <surname>Бернгардт</surname>
       <given-names>Олег Игоревич</given-names>
      </name>
      <name xml:lang="en">
       <surname>Berngardt</surname>
       <given-names>Oleg Igorevich</given-names>
      </name>
     </name-alternatives>
     <email>berng@iszf.irk.ru</email>
     <bio xml:lang="ru">
      <p>кандидат физико-математических наук;</p>
     </bio>
     <bio xml:lang="en">
      <p>candidate of physical and mathematical sciences;</p>
     </bio>
     <xref ref-type="aff" rid="aff-1"/>
    </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>
   <pub-date publication-format="print" date-type="pub" iso-8601-date="2025-06-26T16:59:55+03:00">
    <day>26</day>
    <month>06</month>
    <year>2025</year>
   </pub-date>
   <pub-date publication-format="electronic" date-type="pub" iso-8601-date="2025-06-26T16:59:55+03:00">
    <day>26</day>
    <month>06</month>
    <year>2025</year>
   </pub-date>
   <volume>11</volume>
   <issue>2</issue>
   <fpage>19</fpage>
   <lpage>38</lpage>
   <history>
    <date date-type="received" iso-8601-date="2024-12-11T00:00:00+03:00">
     <day>11</day>
     <month>12</month>
     <year>2024</year>
    </date>
    <date date-type="accepted" iso-8601-date="2025-04-28T00:00:00+03:00">
     <day>28</day>
     <month>04</month>
     <year>2025</year>
    </date>
   </history>
   <self-uri xlink:href="https://zh-szf.ru/en/nauka/article/100187/view">https://zh-szf.ru/en/nauka/article/100187/view</self-uri>
   <abstract xml:lang="ru">
    <p>A self-consistent, data-driven approach to classifying data obtained at the ISTP SB RAS mid-latitude coherent scatter radars has been developed. Based on 2021 data, a solution of the problem of automatic data classification is presented without their labeling by an expert and without postulating the number of classes. The algorithm automatically labels the data, determines the optimal number of signal classes observed by the radars, and trains a two-layer classifying neural network of an extremely simple structure. The trajectory calculations use the wave optics method and international reference models of the ionosphere and the geomagnetic field. The model is trained on signals coming from the main lobe of the antenna pattern. During training, to adapt part of the data obtained with improved spectral resolution, it is artificially coarsened to the standard resolution. Each signal class determined by the neural network is interpreted from a physical point of view, using statistical characteristics of the signals belonging to it. The number of classes in the data is demonstrated to range from 23 to 35. The significance of various parameters of the input data is assessed. It is shown that the most important parameters for the classification are the calculated scattering height and the elevation of the trajectory at the scattering point, and the least important are the spectral width of the received signal and the calculated number of reflections from the underlying surface.</p>
   </abstract>
   <trans-abstract xml:lang="en">
    <p>A self-consistent, data-driven approach to classifying data obtained at the ISTP SB RAS mid-latitude coherent scatter radars has been developed. Based on 2021 data, a solution of the problem of automatic data classification is presented without their labeling by an expert and without postulating the number of classes. The algorithm automatically labels the data, determines the optimal number of signal classes observed by the radars, and trains a two-layer classifying neural network of an extremely simple structure. The trajectory calculations use the wave optics method and international reference models of the ionosphere and the geomagnetic field. The model is trained on signals coming from the main lobe of the antenna pattern. During training, to adapt part of the data obtained with improved spectral resolution, it is artificially coarsened to the standard resolution. Each signal class determined by the neural network is interpreted from a physical point of view, using statistical characteristics of the signals belonging to it. The number of classes in the data is demonstrated to range from 23 to 35. The significance of various parameters of the input data is assessed. It is shown that the most important parameters for the classification are the calculated scattering height and the elevation of the trajectory at the scattering point, and the least important are the spectral width of the received signal and the calculated number of reflections from the underlying surface.</p>
   </trans-abstract>
   <kwd-group xml:lang="ru">
    <kwd>decameter radar</kwd>
    <kwd>SECIRA</kwd>
    <kwd>ionosphere</kwd>
    <kwd>automatic classification</kwd>
   </kwd-group>
   <kwd-group xml:lang="en">
    <kwd>decameter radar</kwd>
    <kwd>SECIRA</kwd>
    <kwd>ionosphere</kwd>
    <kwd>automatic classification</kwd>
   </kwd-group>
   <funding-group>
    <funding-statement xml:lang="ru">The research was financially supported the Russian Science Foundation (Grant No. 24-22-00436) [https://rscf.ru/project/24-22-00 436/]</funding-statement>
    <funding-statement xml:lang="en">The research was financially supported the Russian Science Foundation (Grant No. 24-22-00436) [https://rscf.ru/project/24-22-00 436/]</funding-statement>
   </funding-group>
  </article-meta>
 </front>
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