Daniel J. Emmons, Dong L. Wu, N. Swarnalingam, Ashar F. Ali, Joseph A. Ellis, Kyle E. Fitch, Kenneth S. Obenberger
{"title":"Improved models for estimating sporadic-E intensity from GNSS radio occultation measurements","authors":"Daniel J. Emmons, Dong L. Wu, N. Swarnalingam, Ashar F. Ali, Joseph A. Ellis, Kyle E. Fitch, Kenneth S. Obenberger","doi":"10.3389/fspas.2023.1327979","DOIUrl":null,"url":null,"abstract":"Several models for estimating sporadic-E intensity from Global Navigation Satellite System (GNSS) radio occultation (RO) observation have previously been developed using a single perturbation or intensity parameter, such as phase-based total electron content (TEC) or the amplitude-based S4 index. Here, we outline two new models that use a combination of phase and amplitude parameters for the L1 and L2 signals. These models show a significant improvement over the baseline models used for comparison. Furthermore, the GNSS-RO parameters are compared with several different ionosonde intensity parameters including the direct foEs and fbEs measurements along with the metallic-ion based foμEs and fbμEs parameters which account for the background E-region density. Interestingly, the phase-based σϕ scintillation index shows the strongest correlation to foEs and fbEs while amplitude-based S4 shows the strongest correlation to foμEs and fbμEs. While the metallic-ion based foμEs and fbμEs parameters are physically ideal for GNSS-RO observations, we show difficulties in practical implementation due to the reliance on a background E-region density estimate using a model such as the International Reference Ionosphere (IRI). Ultimately, we provide two improved sporadic-E intensity models that can be used for future GNSS-RO based studies along with a recommendation to compare against the ionosonde-based foEs parameter.","PeriodicalId":46793,"journal":{"name":"Frontiers in Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":2.6000,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers in Astronomy and Space Sciences","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.3389/fspas.2023.1327979","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Several models for estimating sporadic-E intensity from Global Navigation Satellite System (GNSS) radio occultation (RO) observation have previously been developed using a single perturbation or intensity parameter, such as phase-based total electron content (TEC) or the amplitude-based S4 index. Here, we outline two new models that use a combination of phase and amplitude parameters for the L1 and L2 signals. These models show a significant improvement over the baseline models used for comparison. Furthermore, the GNSS-RO parameters are compared with several different ionosonde intensity parameters including the direct foEs and fbEs measurements along with the metallic-ion based foμEs and fbμEs parameters which account for the background E-region density. Interestingly, the phase-based σϕ scintillation index shows the strongest correlation to foEs and fbEs while amplitude-based S4 shows the strongest correlation to foμEs and fbμEs. While the metallic-ion based foμEs and fbμEs parameters are physically ideal for GNSS-RO observations, we show difficulties in practical implementation due to the reliance on a background E-region density estimate using a model such as the International Reference Ionosphere (IRI). Ultimately, we provide two improved sporadic-E intensity models that can be used for future GNSS-RO based studies along with a recommendation to compare against the ionosonde-based foEs parameter.