{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,8]],"date-time":"2026-05-08T04:16:54Z","timestamp":1778213814293,"version":"3.51.4"},"reference-count":30,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,6,6]],"date-time":"2022-06-06T00:00:00Z","timestamp":1654473600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Key Research Program of the Chinese Academy of Sciences","award":["ZDBS-SSW-TLC00103"],"award-info":[{"award-number":["ZDBS-SSW-TLC00103"]}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["E1PD300445"],"award-info":[{"award-number":["E1PD300445"]}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["91952111, 42174192 and U1831137"],"award-info":[{"award-number":["91952111, 42174192 and U1831137"]}]},{"name":"Pandeng Program of National Space Science Center","award":["ZDBS-SSW-TLC00103"],"award-info":[{"award-number":["ZDBS-SSW-TLC00103"]}]},{"name":"Pandeng Program of National Space Science Center","award":["E1PD300445"],"award-info":[{"award-number":["E1PD300445"]}]},{"name":"Pandeng Program of National Space Science Center","award":["91952111, 42174192 and U1831137"],"award-info":[{"award-number":["91952111, 42174192 and U1831137"]}]},{"name":"National Natural Science Foundation of China","award":["ZDBS-SSW-TLC00103"],"award-info":[{"award-number":["ZDBS-SSW-TLC00103"]}]},{"name":"National Natural Science Foundation of China","award":["E1PD300445"],"award-info":[{"award-number":["E1PD300445"]}]},{"name":"National Natural Science Foundation of China","award":["91952111, 42174192 and U1831137"],"award-info":[{"award-number":["91952111, 42174192 and U1831137"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The radio-occultation technique can provide vertical profiles of planetary ionospheric and atmospheric parameters, which merit the planetary-climate and space-weather scientific research so far. The Tianwen-1 one-way single-frequency radio-occultation technique was developed to retrieve Mars ionospheric and atmospheric parameters. The first radio-occultation event observation experiment was conducted on 5 August 2021. The retrieved excess Doppler frequency, bending angle, refractivity, electron density, neutral mass density, pressure and temperature profiles are presented. The Mars ionosphere M1 (M2) layer peak height is at 140 km (105 km) with a peak density of about 3.7 \u00d7 1010 el\/m3 (5.3 \u00d7 1010 el\/m3) in the retrieved electron-density profile. A planetary boundary layer (\u22122.35 km~5 km), a troposphere (temperature decreases with height) and a stratosphere (24 km\u201340 km) clearly appear in the retrieved temperature profile below 50 km. Results show that Tianwen-1 radio occultation data are scientifically reliable and useful for further Mars climate and space-weather studies.<\/jats:p>","DOI":"10.3390\/rs14112718","type":"journal-article","created":{"date-parts":[[2022,6,7]],"date-time":"2022-06-07T00:10:33Z","timestamp":1654560633000},"page":"2718","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["First Observations of Mars Atmosphere and Ionosphere with Tianwen-1 Radio-Occultation Technique on 5 August 2021"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5944-682X","authenticated-orcid":false,"given":"Xiong","family":"Hu","sequence":"first","affiliation":[{"name":"National Space Science Center, State Key Lab of Solar Activity and Space Weather, The Chinese Academy of Sciences, Beijing 100190, 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China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bo","family":"Xia","sequence":"additional","affiliation":[{"name":"Shanghai Astronomy Observatory, The Chinese Academy of Sciences, Shanghai 200030, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Junfeng","family":"Yang","sequence":"additional","affiliation":[{"name":"National Space Science Center, State Key Lab of Solar Activity and Space Weather, The Chinese Academy of Sciences, Beijing 100190, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cui","family":"Tu","sequence":"additional","affiliation":[{"name":"National Space Science Center, State Key Lab of Solar Activity and Space Weather, The Chinese Academy of Sciences, Beijing 100190, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dan","family":"Liu","sequence":"additional","affiliation":[{"name":"National Space Science Center, State Key Lab of Solar Activity and Space Weather, The Chinese 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