{"id":"https://openalex.org/W3118703228","doi":"https://doi.org/10.1109/access.2021.3049451","title":"Global Comparison of F2-Layer Peak Parameters Estimated by IRI-2016 With Ionospheric Radio Occultation Data During Solar Minimum","display_name":"Global Comparison of F2-Layer Peak Parameters Estimated by IRI-2016 With Ionospheric Radio Occultation Data During Solar Minimum","publication_year":2021,"publication_date":"2021-01-01","ids":{"openalex":"https://openalex.org/W3118703228","doi":"https://doi.org/10.1109/access.2021.3049451","mag":"3118703228"},"language":"en","primary_location":{"id":"doi:10.1109/access.2021.3049451","is_oa":true,"landing_page_url":"https://doi.org/10.1109/access.2021.3049451","pdf_url":"https://ieeexplore.ieee.org/ielx7/6287639/9312710/09314076.pdf","source":{"id":"https://openalex.org/S2485537415","display_name":"IEEE Access","issn_l":"2169-3536","issn":["2169-3536"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Access","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://ieeexplore.ieee.org/ielx7/6287639/9312710/09314076.pdf","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5006413981","display_name":"Weihua Bai","orcid":"https://orcid.org/0000-0002-7002-787X"},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]},{"id":"https://openalex.org/I4210165038","display_name":"University of Chinese Academy of Sciences","ror":"https://ror.org/05qbk4x57","country_code":"CN","type":"education","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210165038"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Weihua Bai","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I4210165038"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5085463374","display_name":"Guangyuan Tan","orcid":"https://orcid.org/0000-0003-1896-3203"},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Guangyuan Tan","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":"https://orcid.org/0000-0003-1896-3203","affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5110749300","display_name":"Yueqiang Sun","orcid":null},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]},{"id":"https://openalex.org/I4210165038","display_name":"University of Chinese Academy of Sciences","ror":"https://ror.org/05qbk4x57","country_code":"CN","type":"education","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210165038"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Yueqiang Sun","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I4210165038"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5056864848","display_name":"Junming Xia","orcid":"https://orcid.org/0000-0002-3876-1708"},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Junming Xia","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5100946755","display_name":"Qifei Du","orcid":null},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Qifei Du","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5056804738","display_name":"Guanglin Yang","orcid":"https://orcid.org/0000-0002-0121-1059"},"institutions":[{"id":"https://openalex.org/I141301092","display_name":"China Meteorological Administration","ror":"https://ror.org/00bx3rb98","country_code":"CN","type":"government","lineage":["https://openalex.org/I141301092"]},{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Guanglin Yang","raw_affiliation_strings":["National Meteorological Center, Chinese Meteorological Administration, Beijing, China","National Satellite Meteorological Center, Chinese Meteorological Administration, Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"National Meteorological Center, Chinese Meteorological Administration, Beijing, China","institution_ids":["https://openalex.org/I141301092"]},{"raw_affiliation_string":"National Satellite Meteorological Center, Chinese Meteorological Administration, Beijing, China","institution_ids":["https://openalex.org/I141301092"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5019424514","display_name":"Xiangguang Meng","orcid":"https://orcid.org/0000-0002-4132-3442"},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Xiangguang Meng","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5061964055","display_name":"Danyang Zhao","orcid":"https://orcid.org/0000-0002-5148-408X"},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Danyang Zhao","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5037587360","display_name":"Congliang Liu","orcid":"https://orcid.org/0000-0003-2660-1931"},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Congliang Liu","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5047878660","display_name":"Yuerong Cai","orcid":null},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Yuerong Cai","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5110734982","display_name":"Dongwei Wang","orcid":null},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Dongwei Wang","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5079500908","display_name":"Cong Yin","orcid":"https://orcid.org/0000-0002-0238-4568"},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Cong Yin","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5041657651","display_name":"Peng Hu","orcid":"https://orcid.org/0000-0001-8323-8898"},"institutions":[{"id":"https://openalex.org/I19820366","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35","country_code":"CN","type":"government","lineage":["https://openalex.org/I19820366"]},{"id":"https://openalex.org/I4210115570","display_name":"National Space Science Center","ror":"https://ror.org/02nnjtm50","country_code":"CN","type":"facility","lineage":["https://openalex.org/I19820366","https://openalex.org/I4210115570"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Peng Hu","raw_affiliation_strings":["Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Beijing Key Laboratory of Space Environment Exploration, Chinese Academy of Sciences, Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"Key Laboratory of Science and Technology on Space Environment Situational Awareness, Chinese Academy of Sciences (CAS), Beijing, China","institution_ids":["https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]},{"raw_affiliation_string":"National Space Science Center, Joint Laboratory on Occultations for Atmosphere and Climate (JLOAC), Chinese Academy of Sciences (NSSC/CAS), Beijing, China","institution_ids":["https://openalex.org/I4210115570","https://openalex.org/I19820366"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":13,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":{"value":1850,"currency":"USD","value_usd":1850},"apc_paid":{"value":1850,"currency":"USD","value_usd":1850},"fwci":0.8011,"has_fulltext":true,"cited_by_count":9,"citation_normalized_percentile":{"value":0.73028307,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":89,"max":99},"biblio":{"volume":"9","issue":null,"first_page":"8920","last_page":"8934"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10159","display_name":"Ionosphere and magnetosphere dynamics","score":1.0,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10159","display_name":"Ionosphere and magnetosphere dynamics","score":1.0,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10655","display_name":"GNSS positioning and interference","score":0.9965999722480774,"subfield":{"id":"https://openalex.org/subfields/2202","display_name":"Aerospace Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T12424","display_name":"Earthquake Detection and Analysis","score":0.9952999949455261,"subfield":{"id":"https://openalex.org/subfields/1908","display_name":"Geophysics"},"field":{"id":"https://openalex.org/fields/19","display_name":"Earth and Planetary Sciences"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/international-reference-ionosphere","display_name":"International Reference Ionosphere","score":0.9438093304634094},{"id":"https://openalex.org/keywords/ionosphere","display_name":"Ionosphere","score":0.880141019821167},{"id":"https://openalex.org/keywords/radio-science","display_name":"Radio Science","score":0.7544875741004944},{"id":"https://openalex.org/keywords/radio-occultation","display_name":"Radio occultation","score":0.6825350522994995},{"id":"https://openalex.org/keywords/cosmic-cancer-database","display_name":"COSMIC cancer database","score":0.5229511857032776},{"id":"https://openalex.org/keywords/solar-minimum","display_name":"Solar minimum","score":0.5120559334754944},{"id":"https://openalex.org/keywords/atmospheric-sciences","display_name":"Atmospheric sciences","score":0.5108439326286316},{"id":"https://openalex.org/keywords/environmental-science","display_name":"Environmental science","score":0.4490703344345093},{"id":"https://openalex.org/keywords/physics","display_name":"Physics","score":0.4418242275714874},{"id":"https://openalex.org/keywords/occultation","display_name":"Occultation","score":0.4221437871456146},{"id":"https://openalex.org/keywords/meteorology","display_name":"Meteorology","score":0.33436739444732666},{"id":"https://openalex.org/keywords/total-electron-content","display_name":"Total electron content","score":0.21618390083312988},{"id":"https://openalex.org/keywords/solar-cycle","display_name":"Solar cycle","score":0.17339438199996948},{"id":"https://openalex.org/keywords/geophysics","display_name":"Geophysics","score":0.16281715035438538},{"id":"https://openalex.org/keywords/tec","display_name":"TEC","score":0.1254514753818512},{"id":"https://openalex.org/keywords/solar-wind","display_name":"Solar wind","score":0.12374359369277954},{"id":"https://openalex.org/keywords/astrophysics","display_name":"Astrophysics","score":0.10796105861663818}],"concepts":[{"id":"https://openalex.org/C2777966019","wikidata":"https://www.wikidata.org/wiki/Q1666845","display_name":"International Reference Ionosphere","level":5,"score":0.9438093304634094},{"id":"https://openalex.org/C116403925","wikidata":"https://www.wikidata.org/wiki/Q162219","display_name":"Ionosphere","level":2,"score":0.880141019821167},{"id":"https://openalex.org/C2779959790","wikidata":"https://www.wikidata.org/wiki/Q2079352","display_name":"Radio Science","level":3,"score":0.7544875741004944},{"id":"https://openalex.org/C2777034083","wikidata":"https://www.wikidata.org/wiki/Q1560557","display_name":"Radio occultation","level":3,"score":0.6825350522994995},{"id":"https://openalex.org/C59375849","wikidata":"https://www.wikidata.org/wiki/Q5013513","display_name":"COSMIC cancer database","level":2,"score":0.5229511857032776},{"id":"https://openalex.org/C171428510","wikidata":"https://www.wikidata.org/wiki/Q2314257","display_name":"Solar minimum","level":5,"score":0.5120559334754944},{"id":"https://openalex.org/C91586092","wikidata":"https://www.wikidata.org/wiki/Q757520","display_name":"Atmospheric sciences","level":1,"score":0.5108439326286316},{"id":"https://openalex.org/C39432304","wikidata":"https://www.wikidata.org/wiki/Q188847","display_name":"Environmental science","level":0,"score":0.4490703344345093},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.4418242275714874},{"id":"https://openalex.org/C131040042","wikidata":"https://www.wikidata.org/wiki/Q202746","display_name":"Occultation","level":2,"score":0.4221437871456146},{"id":"https://openalex.org/C153294291","wikidata":"https://www.wikidata.org/wiki/Q25261","display_name":"Meteorology","level":1,"score":0.33436739444732666},{"id":"https://openalex.org/C165391973","wikidata":"https://www.wikidata.org/wiki/Q844304","display_name":"Total electron content","level":4,"score":0.21618390083312988},{"id":"https://openalex.org/C43867161","wikidata":"https://www.wikidata.org/wiki/Q49385","display_name":"Solar cycle","level":4,"score":0.17339438199996948},{"id":"https://openalex.org/C8058405","wikidata":"https://www.wikidata.org/wiki/Q46255","display_name":"Geophysics","level":1,"score":0.16281715035438538},{"id":"https://openalex.org/C176379880","wikidata":"https://www.wikidata.org/wiki/Q18031939","display_name":"TEC","level":3,"score":0.1254514753818512},{"id":"https://openalex.org/C108411613","wikidata":"https://www.wikidata.org/wiki/Q79833","display_name":"Solar wind","level":3,"score":0.12374359369277954},{"id":"https://openalex.org/C44870925","wikidata":"https://www.wikidata.org/wiki/Q37547","display_name":"Astrophysics","level":1,"score":0.10796105861663818},{"id":"https://openalex.org/C62520636","wikidata":"https://www.wikidata.org/wiki/Q944","display_name":"Quantum mechanics","level":1,"score":0.0},{"id":"https://openalex.org/C115260700","wikidata":"https://www.wikidata.org/wiki/Q11408","display_name":"Magnetic field","level":2,"score":0.0}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.1109/access.2021.3049451","is_oa":true,"landing_page_url":"https://doi.org/10.1109/access.2021.3049451","pdf_url":"https://ieeexplore.ieee.org/ielx7/6287639/9312710/09314076.pdf","source":{"id":"https://openalex.org/S2485537415","display_name":"IEEE Access","issn_l":"2169-3536","issn":["2169-3536"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Access","raw_type":"journal-article"},{"id":"pmh:oai:doaj.org/article:3ba68d6e0b284ae08774a02932817bc1","is_oa":true,"landing_page_url":"https://doaj.org/article/3ba68d6e0b284ae08774a02932817bc1","pdf_url":null,"source":{"id":"https://openalex.org/S4306401280","display_name":"DOAJ (DOAJ: Directory of Open Access Journals)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by-sa","license_id":"https://openalex.org/licenses/cc-by-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"IEEE Access, Vol 9, Pp 8920-8934 (2021)","raw_type":"article"}],"best_oa_location":{"id":"doi:10.1109/access.2021.3049451","is_oa":true,"landing_page_url":"https://doi.org/10.1109/access.2021.3049451","pdf_url":"https://ieeexplore.ieee.org/ielx7/6287639/9312710/09314076.pdf","source":{"id":"https://openalex.org/S2485537415","display_name":"IEEE Access","issn_l":"2169-3536","issn":["2169-3536"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Access","raw_type":"journal-article"},"sustainable_development_goals":[{"score":0.6499999761581421,"id":"https://metadata.un.org/sdg/14","display_name":"Life below water"}],"awards":[{"id":"https://openalex.org/G2027150488","display_name":null,"funder_award_id":"41505030","funder_id":"https://openalex.org/F4320321001","funder_display_name":"National Natural Science Foundation of China"},{"id":"https://openalex.org/G3244359883","display_name":null,"funder_award_id":"41405040","funder_id":"https://openalex.org/F4320321001","funder_display_name":"National Natural Science Foundation of China"},{"id":"https://openalex.org/G3827040457","display_name":null,"funder_award_id":"41606206","funder_id":"https://openalex.org/F4320321001","funder_display_name":"National Natural Science Foundation of China"},{"id":"https://openalex.org/G5598133220","display_name":"\u98ce\u4e91\u4e09\u53f7C/D\u661f\u7535\u79bb\u5c42\u63a9\u661f\u4ea7\u54c1\u7cbe\u5ea6\u8bc4\u4f30\u3001\u6539\u8fdb\u4e0e\u79d1\u5b66\u5e94\u7528\u7814\u7a76","funder_award_id":"42074042","funder_id":"https://openalex.org/F4320321001","funder_display_name":"National Natural Science Foundation of China"},{"id":"https://openalex.org/G6033249286","display_name":null,"funder_award_id":"YZ201129","funder_id":"https://openalex.org/F4320321133","funder_display_name":"Chinese Academy of Sciences"},{"id":"https://openalex.org/G694231766","display_name":null,"funder_award_id":"41775034","funder_id":"https://openalex.org/F4320321001","funder_display_name":"National Natural Science Foundation of China"},{"id":"https://openalex.org/G7901227014","display_name":null,"funder_award_id":"41505016","funder_id":"https://openalex.org/F4320321001","funder_display_name":"National Natural Science Foundation of China"},{"id":"https://openalex.org/G8658565991","display_name":null,"funder_award_id":"41405039","funder_id":"https://openalex.org/F4320321001","funder_display_name":"National Natural Science Foundation of China"},{"id":"https://openalex.org/G8900593993","display_name":null,"funder_award_id":"42074042","funder_id":"https://openalex.org/F4320321133","funder_display_name":"Chinese Academy of Sciences"}],"funders":[{"id":"https://openalex.org/F4320321001","display_name":"National Natural Science Foundation of China","ror":"https://ror.org/01h0zpd94"},{"id":"https://openalex.org/F4320321133","display_name":"Chinese Academy of Sciences","ror":"https://ror.org/034t30j35"},{"id":"https://openalex.org/F4320322037","display_name":"Nuclear Safety and Security Commission","ror":"https://ror.org/05qk3ge34"}],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W3118703228.pdf","grobid_xml":"https://content.openalex.org/works/W3118703228.grobid-xml"},"referenced_works_count":61,"referenced_works":["https://openalex.org/W755589151","https://openalex.org/W976653390","https://openalex.org/W1580521357","https://openalex.org/W1660430253","https://openalex.org/W1965660015","https://openalex.org/W1972984133","https://openalex.org/W1973193809","https://openalex.org/W1973706170","https://openalex.org/W1974790977","https://openalex.org/W1993706128","https://openalex.org/W1996859389","https://openalex.org/W1998109790","https://openalex.org/W2011012882","https://openalex.org/W2013695362","https://openalex.org/W2021442507","https://openalex.org/W2022032575","https://openalex.org/W2022495626","https://openalex.org/W2027312400","https://openalex.org/W2028892603","https://openalex.org/W2033277892","https://openalex.org/W2035348799","https://openalex.org/W2041771889","https://openalex.org/W2044621487","https://openalex.org/W2046686041","https://openalex.org/W2052218979","https://openalex.org/W2060002367","https://openalex.org/W2065514782","https://openalex.org/W2070910721","https://openalex.org/W2075056964","https://openalex.org/W2080019495","https://openalex.org/W2083396789","https://openalex.org/W2087757007","https://openalex.org/W2097795807","https://openalex.org/W2101877435","https://openalex.org/W2104945089","https://openalex.org/W2142329187","https://openalex.org/W2154296673","https://openalex.org/W2156868585","https://openalex.org/W2168987504","https://openalex.org/W2202421850","https://openalex.org/W2332310059","https://openalex.org/W2410015886","https://openalex.org/W2588308723","https://openalex.org/W2613955414","https://openalex.org/W2789369371","https://openalex.org/W2897297840","https://openalex.org/W2902611162","https://openalex.org/W2903568628","https://openalex.org/W2910197183","https://openalex.org/W2919887495","https://openalex.org/W2969315684","https://openalex.org/W2972977047","https://openalex.org/W2980119588","https://openalex.org/W2982861313","https://openalex.org/W3016425593","https://openalex.org/W3020868829","https://openalex.org/W3151362475","https://openalex.org/W6625451591","https://openalex.org/W6637146282","https://openalex.org/W6649598263","https://openalex.org/W6655662232"],"related_works":["https://openalex.org/W581459807","https://openalex.org/W2076760108","https://openalex.org/W2080119763","https://openalex.org/W2385429089","https://openalex.org/W2209680672","https://openalex.org/W3009895728","https://openalex.org/W631171883","https://openalex.org/W2019829304","https://openalex.org/W2388968682","https://openalex.org/W2172062723"],"abstract_inverted_index":{"The":[0,80,204],"F2-layer":[1,89],"peak":[2,24,90],"parameters":[3,25],"of":[4,18,22,41,48,83,124,167,173,207,218],"the":[5,19,23,35,44,49,74,95,114,137,168,174,178,187,190,213,230],"International":[6,81],"Reference":[7],"Ionosphere":[8,66],"(IRI)":[9],"model":[10,30,87],"are":[11,111],"critical":[12],"to":[13,146],"its":[14],"subsequent":[15],"applications":[16],"because":[17],"vital":[20],"role":[21],"in":[26,78,109,128,171,177,186,201,225],"determining":[27],"other":[28],"IRI":[29,50,199],"outputs.":[31],"Therefore,":[32],"we":[33],"analyzed":[34],"statistical":[36,118],"deviation":[37],"and":[38,54,67,70,94,100,133,136,151,220],"ionospheric":[39,55,180],"climatology":[40,154],"NmF2/hmF2":[42],"between":[43,130],"most":[45],"current":[46],"version":[47],"model,":[51],"namely":[52],"IRI-2016,":[53],"radio":[56],"occultation":[57],"(IRO)":[58],"data,":[59,135],"including":[60],"Constellation":[61],"Observing":[62],"System":[63],"for":[64,88,104,140,183,198],"Meteorology":[65],"Climate":[68],"(COSMIC)":[69],"FengYun-3C":[71],"(FY3C),":[72],"during":[73],"recent":[75],"solar":[76],"minimum":[77],"2017-2019.":[79],"Union":[82],"Radio":[84],"Science":[85],"(URSI)":[86],"electron":[91],"density":[92],"(NmF2)":[93],"Bilitza-Sheikh-Eyfrig":[96],"(BSE),":[97],"Altadill-Magdaleno-Torta-Blanch":[98],"(AMTB),":[99],"SHUbin":[101],"(SHU)":[102],"models":[103],"maximum":[105],"ionization":[106],"height":[107],"(hmF2)":[108],"IRI-2016":[110,131,161],"compared":[112],"with":[113,165],"IRO":[115,134,147,169,191,214],"dataset.":[116,215],"A":[117,153],"analysis":[119],"shows":[120,142,156],"a":[121,143,195],"systematic":[122],"offset":[123],"less":[125],"than":[126,149],"10%":[127],"NmF2":[129,158],"URSI":[132,162],"SHU":[138],"option":[139],"hmF2":[141,205,217],"better":[144],"fit":[145],"data":[148,192],"BSE":[150],"AMTB.":[152],"comparison":[155],"that":[157,166],"estimated":[159],"by":[160],"is":[163],"consistent":[164],"dataset":[170],"terms":[172],"general":[175],"trend":[176],"typical":[179],"characteristics;":[181],"except":[182],"some":[184,223],"discrepancies":[185,224],"marine":[188,202],"area,":[189],"may":[193],"provide":[194],"feasible":[196],"reference":[197],"estimation":[200],"regions.":[203],"options":[206],"BSE/AMTB/SHU":[208],"show":[209,222],"hemispheric":[210],"asymmetry":[211],"like":[212],"Moreover,":[216],"BSE/AMTB":[219],"IRO/SHU":[221],"fine":[226],"structures,":[227],"such":[228],"as":[229],"day-night":[231],"reversal":[232],"phenomenon.":[233]},"counts_by_year":[{"year":2026,"cited_by_count":2},{"year":2025,"cited_by_count":2},{"year":2024,"cited_by_count":1},{"year":2023,"cited_by_count":1},{"year":2022,"cited_by_count":2},{"year":2021,"cited_by_count":1}],"updated_date":"2026-06-11T09:08:48.828518","created_date":"2025-10-10T00:00:00"}