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<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" article-type="review-article" dtd-version="1.2" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">Cosmic Research</journal-id><journal-title-group><journal-title xml:lang="en">Cosmic Research</journal-title><trans-title-group xml:lang="ru"><trans-title>Космические исследования</trans-title></trans-title-group></journal-title-group><issn publication-format="print">0023-4206</issn><issn publication-format="electronic">3034-5502</issn><publisher><publisher-name xml:lang="en">The Russian Academy of Sciences</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">689541</article-id><article-id pub-id-type="doi">10.31857/S0023420625030094</article-id><article-id pub-id-type="edn">QAKEFU</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>Articles</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>Статьи</subject></subj-group><subj-group subj-group-type="article-type"><subject>Review Article</subject></subj-group></article-categories><title-group><article-title xml:lang="en">Tomographic methods for studying the upper atmosphere and near-Earth space: current state and development prospects</article-title><trans-title-group xml:lang="ru"><trans-title>Томографические методы исследования верхней атмосферы и околоземного космического пространства: современное состояние и перспективы развития</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Padokhin</surname><given-names>A. M.</given-names></name><name xml:lang="ru"><surname>Падохин</surname><given-names>А. М.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>Lomonosov Moscow State University, Physics Department</p></bio><bio xml:lang="ru"><p>Московский государственный университет имени М.В. Ломоносова, Физический факультет</p></bio><email>achernyshov@cosmos.ru</email><xref ref-type="aff" rid="aff1"/><xref ref-type="aff" rid="aff2"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Chernyshov</surname><given-names>A. A.</given-names></name><name xml:lang="ru"><surname>Чернышов</surname><given-names>А. А.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>achernyshov@cosmos.ru</email><xref ref-type="aff" rid="aff3"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Andreeva</surname><given-names>E. S.</given-names></name><name xml:lang="ru"><surname>Андреева</surname><given-names>Е. С.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>Physics Department</p></bio><bio xml:lang="ru"><p>Физический факультет</p></bio><email>achernyshov@cosmos.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Nazarenko</surname><given-names>M. O.</given-names></name><name xml:lang="ru"><surname>Назаренко</surname><given-names>М. О.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>Physics Department</p></bio><bio xml:lang="ru"><p>Физический факультет</p></bio><email>achernyshov@cosmos.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Andreevsky</surname><given-names>S. E.</given-names></name><name xml:lang="ru"><surname>Андреевский</surname><given-names>С. Е.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>achernyshov@cosmos.ru</email><xref ref-type="aff" rid="aff2"/><xref ref-type="aff" rid="aff3"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Mogilevsky</surname><given-names>M. M.</given-names></name><name xml:lang="ru"><surname>Могилевский</surname><given-names>М. М.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>achernyshov@cosmos.ru</email><xref ref-type="aff" rid="aff3"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">Lomonosov Moscow State University</institution></aff><aff><institution xml:lang="ru">Московский государственный университет имени М.В. Ломоносова</institution></aff></aff-alternatives><aff-alternatives id="aff2"><aff><institution xml:lang="en">Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences</institution></aff><aff><institution xml:lang="ru">Институт земного магнетизма, ионосферы и распространения радиоволн им. Н.В. Пушкова РАН</institution></aff></aff-alternatives><aff-alternatives id="aff3"><aff><institution xml:lang="en">Space Research Institute of the Russian Academy of Sciences</institution></aff><aff><institution xml:lang="ru">Институт космических исследований РАН</institution></aff></aff-alternatives><pub-date date-type="pub" iso-8601-date="2025-06-15" publication-format="electronic"><day>15</day><month>06</month><year>2025</year></pub-date><volume>63</volume><issue>3</issue><issue-title xml:lang="en"/><issue-title xml:lang="ru"/><fpage>322</fpage><lpage>346</lpage><history><date date-type="received" iso-8601-date="2025-08-19"><day>19</day><month>08</month><year>2025</year></date><date date-type="accepted" iso-8601-date="2025-08-19"><day>19</day><month>08</month><year>2025</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2025, Russian Academy of Sciences</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2025, Российская академия наук</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="en">Russian Academy of Sciences</copyright-holder><copyright-holder xml:lang="ru">Российская академия наук</copyright-holder></permissions><self-uri xlink:href="https://journals.eco-vector.com/0023-4206/article/view/689541">https://journals.eco-vector.com/0023-4206/article/view/689541</self-uri><abstract xml:lang="en"><p>The review examines the physical and mathematical formulations of the tomography problem in relation to remote sensing of the atmosphere and near-Earth space. Special attention is given to ionospheric sensing using satellite beacon signals from low-orbit (Parus/Transit/Cassiope, etc.), medium-orbit, and high-orbit (GPS/GLONASS and new global satellite navigation systems) satellites. The capabilities and limitations of 2D low-orbit and 4D high-orbit ionospheric radio tomography methods are discussed, along with the results of radiotomographic reconstructions of electron density distribution at various latitudes under both natural and artificial disturbances. A separate focus is placed on studying small-scale ionospheric irregularities based on satellite signal amplitude scintillation data, as well as challenges in implementing such sensing schemes at high latitudes using GPS/GLONASS signals. Besides, the prospects of tomographic systems for upper atmosphere sensing are discussed, considering the significant reduction in the number of low-orbit satellites, the potential installation of satellite beacons on new platforms (CubeSat), and the use of radio tomography methods in ultraviolet tomography of the upper atmosphere. The first results obtained using the dual-frequency (150/400 MHz) coherent signal transmitter MAYAK onboard the satellites of the Russian <italic>“Ionosphere”</italic> project are presented.</p></abstract><trans-abstract xml:lang="ru"><p>В обзоре рассматриваются физические и математические постановки задачи томографии в приложении к дистанционному зондированию атмосферы и околоземного космического пространства. Особое внимание уделено зондированию ионосферы с использованием сигналов спутниковых радиомаяков на низких (Парус<sub> </sub>/<sub> </sub>Transit<sub> </sub>/<sub> </sub>Cassiope и др.), средних и высоких (GPS/<sub> </sub>ГЛОНАСС и новые глобальные спутниковые навигационные системы) орбитах. Обсуждаются возможности и ограничения методов 2D низкоорбитальной и 4D высокоорбитальной радиотомографии ионосферы и приводятся результаты радиотомографических реконструкций распределения электронной концентрации в различных широтах в условиях естественной и искусственной возмущенности. Отдельно рассматривается задача исследования мелкомасштабных ионосферных неоднородностей по данным о мерцаниях амплитуды спутниковых сигналов, обсуждаются проблемы реализации таких схем зондирования в высоких широтах с использованием сигналов GPS<sub> </sub>/<sub> </sub>ГЛОНАСС. Также обсуждаются перспективы томографических систем зондирования верхней атмосферы с учетом сильно сократившейся группировки низкоорбитальных спутников, возможности установки спутниковых радиомаяков на новые платформы (CubeSat), а также использование методов радиотомографии в задачах УФ-томографии верхней атмосферы. Представлены первые результаты, полученные с использованием двухчастотного передатчика когерентных сигналов 150<sub> </sub>/<sub> </sub>400 МГц МАЯК на спутниках <italic>“Ионосфера-М”</italic> российского проекта “Ионозонд”.</p></trans-abstract><funding-group/></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Зеленый Л.М., Веселовский И.С. Плазменная гелиогеофизика. Москва: Физматлит, 2008.</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Kelley M.C. The Earth’s Ionosphere: Plasma Physics and Electrodynamics. 2nd ed. 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