{"@context":{"@vocab":"https://cir.nii.ac.jp/schema/1.0/","rdfs":"http://www.w3.org/2000/01/rdf-schema#","dc":"http://purl.org/dc/elements/1.1/","dcterms":"http://purl.org/dc/terms/","foaf":"http://xmlns.com/foaf/0.1/","prism":"http://prismstandard.org/namespaces/basic/2.0/","cinii":"http://ci.nii.ac.jp/ns/1.0/","datacite":"https://schema.datacite.org/meta/kernel-4/","ndl":"http://ndl.go.jp/dcndl/terms/","jpcoar":"https://github.com/JPCOAR/schema/blob/master/2.0/"},"@id":"https://cir.nii.ac.jp/crid/1363388845540487296.json","@type":"Article","productIdentifier":[{"identifier":{"@type":"DOI","@value":"10.1029/2008ja013967"}},{"identifier":{"@type":"URI","@value":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2008JA013967"}},{"identifier":{"@type":"URI","@value":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2008JA013967"}}],"dc:title":[{"@value":"Improvement of SuperDARN velocity measurements by estimating the index of refraction in the scattering region using interferometry"}],"description":[{"type":"abstract","notation":[{"@value":"<jats:p>In past calculations of convective velocities from Super Dual Auroral Radar Network (SuperDARN) HF radar observations, the refractive index in the scattering region has not been taken into account, and therefore the inferred ionospheric velocities may be underestimated. In light of the significant contribution by SuperDARN to ionospheric and magnetospheric research, it is important to refine the velocity determination. The refractive index in the ionosphere at SuperDARN observation <jats:italic>F</jats:italic> region altitudes has typical values between 0.8 and close to unity. In the scattering region, where conditions are more extreme, the index of refraction may be much lower. A simple application of Snell's law in spherical coordinates (Bouguer's law) suggests that a proxy for the index of refraction at the scattering location can be determined by measuring the elevation angle of the returned ionospheric radar signal. Using this approximation for refractive index, the Doppler velocity calculation can be refined for each SuperDARN ionospheric echo, using the elevation angles obtained from the SuperDARN interferometer data. A velocity comparison of DMSP and SuperDARN observations has revealed that the SuperDARN speeds were systematically lower than the DMSP speeds. A linear regression analysis of the velocity comparisons found a best fit slope of 0.74. When the elevation angle data were used to estimate refractive index, the best fit slope rose 12% to 0.83. As most SuperDARN radars employ an interferometer antenna array for elevation angle measurements, the improvement in velocity estimates can be done routinely using the method outlined in this paper.</jats:p>"}]}],"creator":[{"@id":"https://cir.nii.ac.jp/crid/1380005521909436289","@type":"Researcher","foaf:name":[{"@value":"R. G. Gillies"}],"jpcoar:affiliationName":[{"@value":"Institute of Space and Atmospheric Studies University of Saskatchewan  Saskatoon, Saskatchewan Canada"}]},{"@id":"https://cir.nii.ac.jp/crid/1383388845540487297","@type":"Researcher","foaf:name":[{"@value":"G. C. Hussey"}],"jpcoar:affiliationName":[{"@value":"Institute of Space and Atmospheric Studies University of Saskatchewan  Saskatoon, Saskatchewan Canada"}]},{"@id":"https://cir.nii.ac.jp/crid/1383388845540487301","@type":"Researcher","foaf:name":[{"@value":"G. J. Sofko"}],"jpcoar:affiliationName":[{"@value":"Institute of Space and Atmospheric Studies University of Saskatchewan  Saskatoon, Saskatchewan Canada"}]},{"@id":"https://cir.nii.ac.jp/crid/1383388845540487296","@type":"Researcher","foaf:name":[{"@value":"K. A. McWilliams"}],"jpcoar:affiliationName":[{"@value":"Institute of Space and Atmospheric Studies University of Saskatchewan  Saskatoon, Saskatchewan Canada"}]},{"@id":"https://cir.nii.ac.jp/crid/1383388845540487302","@type":"Researcher","foaf:name":[{"@value":"R. A. D. Fiori"}],"jpcoar:affiliationName":[{"@value":"Institute of Space and Atmospheric Studies University of Saskatchewan  Saskatoon, Saskatchewan Canada"},{"@value":"Natural Resources Canada Geomagnetic Laboratory  Ottawa, Ontario Canada"}]},{"@id":"https://cir.nii.ac.jp/crid/1383388845540487300","@type":"Researcher","foaf:name":[{"@value":"P. Ponomarenko"}],"jpcoar:affiliationName":[{"@value":"Space Physics Group University of Newcastle  Callaghan, New South Wales Australia"}]},{"@id":"https://cir.nii.ac.jp/crid/1380298344859826176","@type":"Researcher","foaf:name":[{"@value":"J.‐P. St.‐Maurice"}],"jpcoar:affiliationName":[{"@value":"Institute of Space and Atmospheric Studies University of Saskatchewan  Saskatoon, Saskatchewan Canada"}]}],"publication":{"publicationIdentifier":[{"@type":"PISSN","@value":"01480227"}],"prism:publicationName":[{"@value":"Journal of Geophysical Research: Space Physics"}],"dc:publisher":[{"@value":"American Geophysical Union (AGU)"}],"prism:publicationDate":"2009-07","prism:volume":"114","prism:number":"A7","prism:startingPage":"A07305"},"reviewed":"false","dc:rights":["http://onlinelibrary.wiley.com/termsAndConditions#vor"],"url":[{"@id":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2008JA013967"},{"@id":"https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2008JA013967"}],"createdAt":"2009-07-09","modifiedAt":"2023-10-31","relatedProduct":[{"@id":"https://cir.nii.ac.jp/crid/1360004229800620800","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"The interconnection between cross‒polar cap convection and the luminosity of polar cap patches"}]},{"@id":"https://cir.nii.ac.jp/crid/1360285708262476032","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Reorganization of polar cap patches through shears in the background plasma convection"}]},{"@id":"https://cir.nii.ac.jp/crid/1360865815685080576","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"On the Creation, Depletion, and End of Life of Polar Cap Patches"}]},{"@id":"https://cir.nii.ac.jp/crid/2051433317026704640","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Comparison of SuperDARN peak electron density estimates based on elevation angle measurements to ionosonde and incoherent scatter radar measurements"}]}],"dataSourceIdentifier":[{"@type":"CROSSREF","@value":"10.1029/2008ja013967"},{"@type":"CROSSREF","@value":"10.1002/2013ja019196_references_DOI_7W0XVTjiWnRNEVTQOjmNQSOsoxS"},{"@type":"CROSSREF","@value":"10.1186/s40623-020-01170-w_references_DOI_7W0XVTjiWnRNEVTQOjmNQSOsoxS"},{"@type":"CROSSREF","@value":"10.1029/2009ja014599_references_DOI_7W0XVTjiWnRNEVTQOjmNQSOsoxS"},{"@type":"CROSSREF","@value":"10.1029/2023ja031739_references_DOI_7W0XVTjiWnRNEVTQOjmNQSOsoxS"}]}