{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T17:59:16Z","timestamp":1775066356523,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2023,8,31]],"date-time":"2023-08-31T00:00:00Z","timestamp":1693440000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"ONR project","award":["73-6C95025"],"award-info":[{"award-number":["73-6C95025"]}]},{"name":"ONR project","award":["DMS-1923221"],"award-info":[{"award-number":["DMS-1923221"]}]},{"DOI":"10.13039\/100000001","name":"NSF","doi-asserted-by":"publisher","award":["73-6C95025"],"award-info":[{"award-number":["73-6C95025"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"NSF","doi-asserted-by":"publisher","award":["DMS-1923221"],"award-info":[{"award-number":["DMS-1923221"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]},{"name":"ONR Summer Faculty Fellowship Program","award":["73-6C95025"],"award-info":[{"award-number":["73-6C95025"]}]},{"name":"ONR Summer Faculty Fellowship Program","award":["DMS-1923221"],"award-info":[{"award-number":["DMS-1923221"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The upcoming technology of wide-swath altimetry from space will enable monitoring the ocean surface at 4\u20135 times better spatial resolution and 2\u20133 times better accuracy than traditional nadir altimeters. This development will provide a chance to directly observe submesoscale sea surface height (SSH) variations that have a typical magnitude of a few centimeters. Taking full advantage of this opportunity requires correct treatment of the correlated SSH errors caused by uncertainties in environmental conditions beneath the satellite and in the geometry and orientation of the on-board interferometer. These observation errors are highly correlated both along and across the surface swath scanned by the satellite, and this presents a significant challenge for accurate processing. In particular, the SWOT precision matrix has off-diagonal elements that are too numerous to allow standard approaches to remain tractable. In this study, we explore the utility of a block-diagonal approximation to the SWOT precision matrix in order to reconstruct SSH variability in the region east of Greenland. An extensive set of 2dVar assimilation experiments demonstrates that the sparse approximation proposed for the precision matrix provides accurate SSH retrievals when the background-to-observation error ratio \u03bd does not exceed 3 and significant wave height is below 2.5 m. We also quantify the range of \u03bd and significant wave heights over which the retrieval accuracy of the exact spatially correlated SWOT error model will outperform the uncorrelated model. In particular, the estimated range is found to be substantially wider (\u03bd&lt;10 with significant wave heights below 8\u201310 m), indicating the potential benefits of further improving the accuracy of approximations for the SWOT precision matrix.<\/jats:p>","DOI":"10.3390\/rs15174277","type":"journal-article","created":{"date-parts":[[2023,8,31]],"date-time":"2023-08-31T11:41:18Z","timestamp":1693482078000},"page":"4277","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["The Effect of Spatially Correlated Errors on Sea Surface Height Retrieval from SWOT Altimetry"],"prefix":"10.3390","volume":"15","author":[{"given":"Max","family":"Yaremchuk","sequence":"first","affiliation":[{"name":"US Naval Research Laboratory, Stennis Space Center, MS 39522, USA"}]},{"given":"Christopher","family":"Beattie","sequence":"additional","affiliation":[{"name":"Department of Mathematics, Virginia Tech, Blacksburg, VA 24061, USA"}]},{"given":"Gleb","family":"Panteleev","sequence":"additional","affiliation":[{"name":"US Naval Research Laboratory, Stennis Space Center, MS 39522, USA"}]},{"given":"Joseph M.","family":"D\u2019Addezio","sequence":"additional","affiliation":[{"name":"US Naval Research Laboratory, Stennis Space Center, MS 39522, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4033-5230","authenticated-orcid":false,"given":"Scott","family":"Smith","sequence":"additional","affiliation":[{"name":"US Naval Research Laboratory, Stennis Space Center, MS 39522, USA"}]}],"member":"1968","published-online":{"date-parts":[[2023,8,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"766","DOI":"10.1109\/JPROC.2010.2043031","article-title":"The surface water and ocean topography mission: Observing terrestrial surface water and oceanic submesoscale eddies","volume":"98","author":"Durand","year":"2010","journal-title":"Proc. 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