{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T14:46:31Z","timestamp":1773845191591,"version":"3.50.1"},"reference-count":32,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2023,3,23]],"date-time":"2023-03-23T00:00:00Z","timestamp":1679529600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["42241112"],"award-info":[{"award-number":["42241112"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["42122032"],"award-info":[{"award-number":["42122032"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["ZBDS-SSW-TLC001"],"award-info":[{"award-number":["ZBDS-SSW-TLC001"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["D020104"],"award-info":[{"award-number":["D020104"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2017186"],"award-info":[{"award-number":["2017186"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2021144"],"award-info":[{"award-number":["2021144"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2018177"],"award-info":[{"award-number":["2018177"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2019153"],"award-info":[{"award-number":["2019153"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["42241112"],"award-info":[{"award-number":["42241112"]}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["42122032"],"award-info":[{"award-number":["42122032"]}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["ZBDS-SSW-TLC001"],"award-info":[{"award-number":["ZBDS-SSW-TLC001"]}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["D020104"],"award-info":[{"award-number":["D020104"]}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["2017186"],"award-info":[{"award-number":["2017186"]}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["2021144"],"award-info":[{"award-number":["2021144"]}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["2018177"],"award-info":[{"award-number":["2018177"]}]},{"name":"Key Research Program of the Chinese Academy of Sciences","award":["2019153"],"award-info":[{"award-number":["2019153"]}]},{"name":"China\u2019s National Space Administration","award":["42241112"],"award-info":[{"award-number":["42241112"]}]},{"name":"China\u2019s National Space Administration","award":["42122032"],"award-info":[{"award-number":["42122032"]}]},{"name":"China\u2019s National Space Administration","award":["ZBDS-SSW-TLC001"],"award-info":[{"award-number":["ZBDS-SSW-TLC001"]}]},{"name":"China\u2019s National Space Administration","award":["D020104"],"award-info":[{"award-number":["D020104"]}]},{"name":"China\u2019s National Space Administration","award":["2017186"],"award-info":[{"award-number":["2017186"]}]},{"name":"China\u2019s National Space Administration","award":["2021144"],"award-info":[{"award-number":["2021144"]}]},{"name":"China\u2019s National Space Administration","award":["2018177"],"award-info":[{"award-number":["2018177"]}]},{"name":"China\u2019s National Space Administration","award":["2019153"],"award-info":[{"award-number":["2019153"]}]},{"name":"Youth Innovation Promotion Association of the Chinese Academy of Sciences","award":["42241112"],"award-info":[{"award-number":["42241112"]}]},{"name":"Youth Innovation Promotion Association of the Chinese Academy of Sciences","award":["42122032"],"award-info":[{"award-number":["42122032"]}]},{"name":"Youth Innovation Promotion Association of the Chinese Academy of Sciences","award":["ZBDS-SSW-TLC001"],"award-info":[{"award-number":["ZBDS-SSW-TLC001"]}]},{"name":"Youth Innovation Promotion Association of the Chinese Academy of Sciences","award":["D020104"],"award-info":[{"award-number":["D020104"]}]},{"name":"Youth Innovation Promotion Association of the Chinese Academy of Sciences","award":["2017186"],"award-info":[{"award-number":["2017186"]}]},{"name":"Youth Innovation Promotion Association of the Chinese Academy of Sciences","award":["2021144"],"award-info":[{"award-number":["2021144"]}]},{"name":"Youth Innovation Promotion Association of the Chinese Academy of Sciences","award":["2018177"],"award-info":[{"award-number":["2018177"]}]},{"name":"Youth Innovation Promotion Association of the Chinese Academy of Sciences","award":["2019153"],"award-info":[{"award-number":["2019153"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>An algorithm has been developed to invert the solar wind parameters from the hydrogen energetic neutral atom (H-ENA) measured in near-Mars space. Supposing the H-ENA is produced by change exchange collision between protons that originated in the solar wind and neutrals in the exosphere, an H-ENA model is established based on the magnetohydrodynamic (MHD) simulation of the solar wind interaction with Mars, to study the H-ENA characteristics. It is revealed that the solar wind H-ENAs are high-speed, low-temperature beams, just like the solar wind, while the magnetosheath H-ENAs are slower and hotter, with broader energy distribution. Assuming Maxwellian velocity distribution, the solar wind H-ENA flux is best fitted by a Gaussian function, from which the solar wind velocity, density, and temperature can be retrieved. Further investigation, based on the ENA flux simulated by the H-ENA model, reveals that the accuracy of inversed solar wind parameters is related to the angular and energy resolutions of the ENA detector. Finally, the algorithm is verified using the H-ENA observations from the Tianwen-1 mission. The upstream solar wind velocity when inversed is close to that of the in situ plasma measurement. Our result suggests the solar wind parameters inversed from H-ENA observation could be an important supplement to the dataset supporting studies on the Martian space environment, where long-term continuous monitoring of the upstream SW condition is lacking.<\/jats:p>","DOI":"10.3390\/rs15071721","type":"journal-article","created":{"date-parts":[[2023,3,23]],"date-time":"2023-03-23T03:07:57Z","timestamp":1679540877000},"page":"1721","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Inversion of Upstream Solar Wind Parameters from ENA Observations at Mars"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7229-4664","authenticated-orcid":false,"given":"Yiteng","family":"Zhang","sequence":"first","affiliation":[{"name":"State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"},{"name":"Key Laboratory of Solar Activity and Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Joint Research and Development Center of Chinese Science Academy and Shen County, Liaocheng 252400, China"}]},{"given":"Lei","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Key Laboratory of Solar Activity and Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Joint Research and Development Center of Chinese Science Academy and Shen County, Liaocheng 252400, China"}]},{"given":"Lianghai","family":"Xie","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Key Laboratory of Solar Activity and Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Joint Research and Development Center of Chinese Science Academy and Shen County, Liaocheng 252400, China"}]},{"given":"Linggao","family":"Kong","sequence":"additional","affiliation":[{"name":"National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Beijing Key Laboratory of Space Environment Exploration, Beijing 100190, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1920-2406","authenticated-orcid":false,"given":"Wenya","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Key Laboratory of Solar Activity and Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"}]},{"given":"Binbin","family":"Tang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Key Laboratory of Solar Activity and Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"}]},{"given":"Jijie","family":"Ma","sequence":"additional","affiliation":[{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"},{"name":"National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Beijing Key Laboratory of Space Environment Exploration, Beijing 100190, China"}]},{"given":"Aibing","family":"Zhang","sequence":"additional","affiliation":[{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"},{"name":"National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"Beijing Key Laboratory of Space Environment Exploration, Beijing 100190, China"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"223","DOI":"10.3847\/1538-4357\/ab5440","article-title":"Angular Scattering in Charge Exchange: Issues and Implications for Secondary Interstellar Hydrogen","volume":"887","author":"Swaczyna","year":"2019","journal-title":"Astrophys. J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3617","DOI":"10.1063\/1.1148389","article-title":"Energetic neutral atom imaging of space plasmas","volume":"68","author":"Gruntman","year":"1997","journal-title":"Rev. Sci. Instrum."},{"key":"ref_3","unstructured":"Wurz, P. (2000). The Outer Heliosphere: Beyond the Planets, Katlenburg-Lindau."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1029\/1999GL010703","article-title":"The Solar Wind interaction with Mars: Locations and shapes of the Bow Shock and the Magnetic Pile-up Boundary from the observations of the MAG\/ER experiment onboard Mars Global Surveyor","volume":"27","author":"Vignes","year":"2000","journal-title":"Geophys. Res. Lett."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1016\/j.icarus.2005.08.024","article-title":"First ENA observations at Mars: Subsolar ENA jet","volume":"182","author":"Futaana","year":"2006","journal-title":"Icarus"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"424","DOI":"10.1016\/j.icarus.2005.09.019","article-title":"First ENA observations at Mars: ENA emissions from the martian upper atmosphere","volume":"182","author":"Futaana","year":"2006","journal-title":"Icarus"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1016\/j.icarus.2005.10.027","article-title":"First ENA observations at Mars: FCharge exchange ENAs produced in the magnetosheath","volume":"182","author":"Gunell","year":"2006","journal-title":"Icarus"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"840","DOI":"10.1016\/j.pss.2007.12.013","article-title":"ENA detection in the dayside of Mars: ASPERA-3 NPD statistical study","volume":"56","author":"Mura","year":"2008","journal-title":"Planet. Space Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"E12012","DOI":"10.1029\/2008JE003139","article-title":"Tailward flow of energetic neutral atoms observed at Mars","volume":"113","author":"Galli","year":"2008","journal-title":"J. Geophys. Res."},{"key":"ref_10","unstructured":"Galli, A. (2008). Energetic Neutral Atoms Imaging of Mars, Venus, and the Heliosphere, University of Bern."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1000","DOI":"10.1016\/j.pss.2008.09.016","article-title":"Statistical analysis of the observations of the MEX\/ASPERA-3 NPI in the shadow","volume":"57","author":"Milillo","year":"2009","journal-title":"Planet. Space Sci."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Ma, J., Kong, L., Li, W., Zhang, Y., Wurz, P., Galli, A., Tang, B., Xie, L., Zhang, A., and Li, L. (2022, January 12\u201316). Solar Wind Energetic Neutral Atom Observation at Mars by MINPA Onboard the Tianwen-1 Orbiter. Proceedings of the Fall Meeting 2022, AGU, Chicago, IL, USA.","DOI":"10.5194\/egusphere-egu23-5058"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"22183","DOI":"10.1029\/97JA01662","article-title":"Charge exchange near Mars: The solar wind absorption and energetic neutral atom production","volume":"102","author":"Kallio","year":"1997","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1002\/2015JA021653","article-title":"Emission of hydrogen energetic neutral atoms from the Martian subsolar magnetosheath","volume":"121","author":"Wang","year":"2016","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"8730","DOI":"10.1029\/2018JA025188","article-title":"Precipitation of Hydrogen Energetic Neutral Atoms at the Upper Atmosphere of Mars","volume":"123","author":"Wang","year":"2018","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1277","DOI":"10.1029\/2001JA000325","article-title":"Energetic neutral atoms at Mars\u20141. Imaging of solar wind protons","volume":"107","author":"Holmstrom","year":"2002","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"11","DOI":"10.3847\/1538-4357\/ac4606","article-title":"Energetic Neutral Atoms near Mars: Predicted Distributions Based on MAVEN Measurements","volume":"927","author":"Ramstad","year":"2022","journal-title":"Astrophys. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"448","DOI":"10.1016\/j.icarus.2005.12.019","article-title":"Energetic Neutral Atoms (ENA) at Mars: Properties of the hydrogen atoms produced upstream of the martian bow shock and implications for ENA sounding technique around non-magnetized planets","volume":"182","author":"Kallio","year":"2006","journal-title":"Icarus"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"A12218","DOI":"10.1029\/2010JA015770","article-title":"Comparisons between ion distributions retrieved from ENA images of the ring current and contemporaneous, multipoint ion measurements recorded in situ during the major magnetic storm of 15 May 2005","volume":"115","author":"Lu","year":"2010","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"e2020GL089362","DOI":"10.1029\/2020GL089362","article-title":"Neutral Atom Imaging of the Solar Wind-Magnetosphere-Exosphere Interaction Near the Subsolar Magnetopause","volume":"47","author":"Fuselier","year":"2020","journal-title":"Geophys. Res. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"7248","DOI":"10.1029\/2018GL077707","article-title":"The Impact and Solar Wind Proxy of the 2017 September ICME Event at Mars","volume":"45","author":"Ma","year":"2018","journal-title":"Geophys. Res. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.pss.2005.04.002","article-title":"Planetary ENA imaging: Effects of different interaction models for Mars","volume":"54","author":"Gunell","year":"2006","journal-title":"Planet. Space Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"A12213","DOI":"10.1029\/2005JA011298","article-title":"Charge transfer cross sections for energetic neutral atom data analysis","volume":"110","author":"Lindsay","year":"2005","journal-title":"J. Geophys. Res."},{"key":"ref_24","unstructured":"Rinsuke, I., Tatsuo, T., Toshizo, S., and Phaneuf, R.A. (1993). Analytic Cross Sections for Collision of H, H2, He and Li Atoms and Ions with Atoms and Melecules, Japan Atomic Energy Research Institute."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"9113","DOI":"10.1002\/2015GL065218","article-title":"MHD model results of solar wind interaction with Mars and comparison with MAVEN plasma observations","volume":"42","author":"Ma","year":"2015","journal-title":"Geophys. Res. Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"A07211","DOI":"10.1029\/2003JA010367","article-title":"Three-dimensional, multispecies, high spatial resolution MHD studies of the solar wind interaction with Mars","volume":"109","author":"Ma","year":"2004","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_27","unstructured":"Chamberlain, J.W., and Hunten, D.M. (1987). Theory of Planetary Atmospheres, Academic Press Inc., Ltd."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"7635","DOI":"10.1002\/2013JA018876","article-title":"Directionality and variability of energetic neutral hydrogen fluxes observed by Mars Express","volume":"118","author":"Wang","year":"2013","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"333","DOI":"10.26464\/epp2020053","article-title":"Mars Ion and Neutral Particle Analyzer (MINPA) for Chinese Mars Exploration Mission (Tianwen-1): Design and ground calibration","volume":"4","author":"Kong","year":"2020","journal-title":"Earth Planet. Phys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1","DOI":"10.26464\/epp2022014","article-title":"Tianwen-1 MINPA observations in the solar wind","volume":"6","author":"Zhang","year":"2022","journal-title":"Earth Planet. Phys."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1461","DOI":"10.1029\/92JA02197","article-title":"Magnetic pulsations from 0.1 to 4.0 Hz and associated plasma properties in the Earth\u2019s subsolar magnetosheath and plasma depletion layer","volume":"98","author":"Anderson","year":"1993","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"165","DOI":"10.3847\/1538-4357\/ac5f00","article-title":"Statistical Analysis of the Distribution and Evolution of Mirror Structures in the Martian Magnetosheath","volume":"929","author":"Jin","year":"2022","journal-title":"Astrophys. J."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/7\/1721\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:01:12Z","timestamp":1760122872000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/7\/1721"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,3,23]]},"references-count":32,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2023,4]]}},"alternative-id":["rs15071721"],"URL":"https:\/\/doi.org\/10.3390\/rs15071721","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,3,23]]}}}