{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,22]],"date-time":"2026-01-22T05:32:19Z","timestamp":1769059939559,"version":"3.49.0"},"reference-count":53,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2021,1,29]],"date-time":"2021-01-29T00:00:00Z","timestamp":1611878400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The ionospheric D-region affects propagation of electromagnetic waves including ground-based signals and satellite signals during its intensive disturbances. Consequently, the modeling of electromagnetic propagation in the D-region is important in many technological domains. One of sources of uncertainty in the modeling of the disturbed D-region is the poor knowledge of its parameters in the quiet state at the considered location and time period. We present the Quiet Ionospheric D-Region (QIonDR) model based on data collected in the ionospheric D-region remote sensing by very low\/low frequency (VLF\/LF) signals and the Long-Wave Propagation Capability (LWPC) numerical model. The QIonDR model provides both Wait\u2019s parameters and the electron density in the D-region area of interest at a given daytime interval. The proposed model consists of two steps. In the first step, Wait\u2019s parameters are modeled during the quiet midday periods as a function of the daily sunspot number, related to the long-term variations during solar cycle, and the seasonal parameter, providing the seasonal variations. In the second step, the output of the first step is used to model Wait\u2019s parameters during the whole daytime. The proposed model is applied to VLF data acquired in Serbia and related to the DHO and ICV signals emitted in Germany and Italy, respectively. As a result, the proposed methodology provides a numerical tool to model the daytime Wait\u2019s parameters over the middle and low latitudes and an analytical expression valid over a part of Europe for midday parameters.<\/jats:p>","DOI":"10.3390\/rs13030483","type":"journal-article","created":{"date-parts":[[2021,1,30]],"date-time":"2021-01-30T06:22:20Z","timestamp":1611987740000},"page":"483","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Quiet Ionospheric D-Region (QIonDR) Model Based on VLF\/LF Observations"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0462-8383","authenticated-orcid":false,"given":"Aleksandra","family":"Nina","sequence":"first","affiliation":[{"name":"Institute of Physics Belgrade, University of Belgrade, 11080 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7621-5014","authenticated-orcid":false,"given":"Giovanni","family":"Nico","sequence":"additional","affiliation":[{"name":"Istituto per le Applicazioni del Calcolo (IAC), Consiglio Nazionale delle Ricerche (CNR), 70126 Bari, Italy"},{"name":"Department of Cartography and Geoinformatics, Institute of Earth Sciences, Saint Petersburg State University (SPSU), 199034 Saint Petersburg, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1287-2792","authenticated-orcid":false,"given":"Sr\u0111an T.","family":"Mitrovi\u0107","sequence":"additional","affiliation":[{"name":"Novelic, 11000 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vladimir M.","family":"\u010cade\u017e","sequence":"additional","affiliation":[{"name":"Astronomical Observatory, 11060 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ivana R.","family":"Milo\u0161evi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Physics Belgrade, University of Belgrade, 11080 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9702-3879","authenticated-orcid":false,"given":"Milan","family":"Radovanovi\u0107","sequence":"additional","affiliation":[{"name":"Geographical Institute \u201cJovan Cviji\u0107\u201d SASA, 11000 Belgrade, Serbia"},{"name":"Institute of Sports, Tourism and Service, South Ural State University, 454080 Chelyabinsk, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2398-7664","authenticated-orcid":false,"given":"Luka \u010c.","family":"Popovi\u0107","sequence":"additional","affiliation":[{"name":"Astronomical Observatory, 11060 Belgrade, Serbia"},{"name":"Department of Astronomy, Faculty of Mathematics, University of Belgrade, 11000 Belgrade, Serbia"},{"name":"Faculty of Science, University of Banja Luka, 78000 Banja Luka, Republic of Srpska, Bosnia and Herzegovina"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"788","DOI":"10.1016\/j.asr.2004.12.076","article-title":"The ionosphere, radio navigation, and global navigation satellite systems","volume":"35","author":"Kintner","year":"2005","journal-title":"Adv. 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