{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T05:03:37Z","timestamp":1774415017412,"version":"3.50.1"},"reference-count":11,"publisher":"American Geophysical Union (AGU)","issue":"16","license":[{"start":{"date-parts":[[2003,8,16]],"date-time":"2003-08-16T00:00:00Z","timestamp":1060992000000},"content-version":"vor","delay-in-days":15,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Geophysical Research Letters"],"published-print":{"date-parts":[[2003,8]]},"abstract":"The Global Positioning System (GPS) transmits two frequencies, allowing users to correct for the first\u2010order ionospheric signal group delay (or phase advance) of 1\u201350 m. The second\u2010order ionospheric term, caused by the Faraday rotation effect induced by the Earth magnetic field, is about 1000 times smaller and usually ignored. In this study, we implement the 2nd\u2010order correction suggested by Bassiri and Hajj<\/jats:italic> [1993]<\/jats:ext-link> and investigate its effect on GPS\u2010inferred station positions. The correction causes a latitude dependent \u223c0.1\u20130.5 cm southward shift to the position which is roughly proportional to the integrated electron density above the receiver, and has strong diurnal, seasonal and decadal signatures. By analyzing a three\u2010year time series of equatorial station positions obtained without the 2nd\u2010order correction, a strong semi\u2010annual north\u2010south oscillation is observed, the origin of which has not been hitherto explained. We verify that this apparent oscillation can be largely removed once the 2nd\u2010order correction is applied.<\/jats:p>","DOI":"10.1029\/2003gl017639","type":"journal-article","created":{"date-parts":[[2003,8,15]],"date-time":"2003-08-15T19:56:10Z","timestamp":1060977370000},"source":"Crossref","is-referenced-by-count":204,"title":["The effect of the second order GPS ionospheric correction on receiver positions"],"prefix":"10.1029","volume":"30","author":[{"given":"S.","family":"Kedar","sequence":"first","affiliation":[{"name":"Jet Propulsion Laboratory California Institute of Technology Pasadena California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"G. A.","family":"Hajj","sequence":"additional","affiliation":[{"name":"Jet Propulsion Laboratory California Institute of Technology Pasadena California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"B. D.","family":"Wilson","sequence":"additional","affiliation":[{"name":"Jet Propulsion Laboratory California Institute of Technology Pasadena California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M. B.","family":"Heflin","sequence":"additional","affiliation":[{"name":"Jet Propulsion Laboratory California Institute of Technology Pasadena California USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"13","published-online":{"date-parts":[[2003,8,16]]},"reference":[{"key":"e_1_2_6_2_1","doi-asserted-by":"publisher","DOI":"10.1029\/RS015i005p01009"},{"key":"e_1_2_6_3_1","first-page":"280","article-title":"Higher\u2010order ionospheric effects on the global positioning systems observables and means of modeling them","volume":"18","author":"Bassiri S.","year":"1993","journal-title":"Manuscripta Geodetica"},{"key":"e_1_2_6_4_1","first-page":"205","article-title":"An improved model for dual frequency ionospheric correction of GPS observations","volume":"16","author":"Brunner F. 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Papas 1965 McGraw\u2010Hill New York"},{"key":"e_1_2_6_11_1","doi-asserted-by":"publisher","DOI":"10.1029\/JA073i013p04325"},{"key":"e_1_2_6_12_1","doi-asserted-by":"publisher","DOI":"10.2514\/3.20600"}],"container-title":["Geophysical Research Letters"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1029%2F2003GL017639","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/pdf\/10.1029\/2003GL017639","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,31]],"date-time":"2023-10-31T14:29:27Z","timestamp":1698762567000},"score":1,"resource":{"primary":{"URL":"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/10.1029\/2003GL017639"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2003,8]]},"references-count":11,"journal-issue":{"issue":"16","published-print":{"date-parts":[[2003,8]]}},"alternative-id":["10.1029\/2003GL017639"],"URL":"https:\/\/doi.org\/10.1029\/2003gl017639","archive":["Portico"],"relation":{},"ISSN":["0094-8276","1944-8007"],"issn-type":[{"value":"0094-8276","type":"print"},{"value":"1944-8007","type":"electronic"}],"subject":[],"published":{"date-parts":[[2003,8]]},"article-number":"2003GL017639"}}