{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,4]],"date-time":"2026-07-04T03:03:55Z","timestamp":1783134235700,"version":"3.54.6"},"reference-count":36,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2022,8,22]],"date-time":"2022-08-22T00:00:00Z","timestamp":1661126400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"ESA Baltic+ Sea Level project","award":["ESA AO\/1-9172\/17\/I-BG - BALTIC +"],"award-info":[{"award-number":["ESA AO\/1-9172\/17\/I-BG - BALTIC +"]}]},{"name":"ESA Baltic+ Sea Level project","award":["4000126590\/19\/I\/BG"],"award-info":[{"award-number":["4000126590\/19\/I\/BG"]}]},{"name":"ESA Sea Level Climate Change Initiative","award":["ESA AO\/1-9172\/17\/I-BG - BALTIC +"],"award-info":[{"award-number":["ESA AO\/1-9172\/17\/I-BG - BALTIC +"]}]},{"name":"ESA Sea Level Climate Change Initiative","award":["4000126590\/19\/I\/BG"],"award-info":[{"award-number":["4000126590\/19\/I\/BG"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The sea level retrievals from the latest generation of radar altimeters (the SAR altimeters) are still challenging in the coastal zone and areas covered by sea ice and require a dedicated fitting (retracking) strategy for the waveforms. In the framework of the European Space Agency\u2019s Baltic + Sea Level (ESA Baltic SEAL) project, an empirical retracking strategy (ALES + SAR), including a dedicated sea state bias correction, has been designed to improve the sea level observations in the Baltic Sea, characterised by a jagged coastline and seasonal sea ice coverage, without compromising the quality of open ocean data. In this work, the performances of ALES + SAR are validated against in-situ data in the Baltic Sea. Moreover, variance, crossover differences and power spectral density of the open ocean data are evaluated on a global scale. The results show that ALES + SAR performances are of comparable quality to the ones obtained using physical-based retrackers, with relevant advantages in coastal and sea ice areas in terms of quality and quantity of the sea level data.<\/jats:p>","DOI":"10.3390\/rs14164122","type":"journal-article","created":{"date-parts":[[2022,8,22]],"date-time":"2022-08-22T23:49:56Z","timestamp":1661212196000},"page":"4122","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Validation of an Empirical Subwaveform Retracking Strategy for SAR Altimetry"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3372-3948","authenticated-orcid":false,"given":"Marcello","family":"Passaro","sequence":"first","affiliation":[{"name":"Deutsches Geod\u00e4tisches Forschungsinstitut, Technische Universit\u00e4t M\u00fcnchen (DGFI-TUM), 80333 M\u00fcnchen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Rautiainen","sequence":"additional","affiliation":[{"name":"Finnish Meteorological Institute, FI-00101 Helsinki, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8940-4639","authenticated-orcid":false,"given":"Denise","family":"Dettmering","sequence":"additional","affiliation":[{"name":"Deutsches Geod\u00e4tisches Forschungsinstitut, Technische Universit\u00e4t M\u00fcnchen (DGFI-TUM), 80333 M\u00fcnchen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Restano","sequence":"additional","affiliation":[{"name":"SERCO\/ESRIN, Largo Galileo Galilei, I-00044 Frascati, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9342-0335","authenticated-orcid":false,"given":"Michael G.","family":"Hart-Davis","sequence":"additional","affiliation":[{"name":"Deutsches Geod\u00e4tisches Forschungsinstitut, Technische Universit\u00e4t M\u00fcnchen (DGFI-TUM), 80333 M\u00fcnchen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6872-3668","authenticated-orcid":false,"given":"Florian","family":"Schlembach","sequence":"additional","affiliation":[{"name":"Deutsches Geod\u00e4tisches Forschungsinstitut, Technische Universit\u00e4t M\u00fcnchen (DGFI-TUM), 80333 M\u00fcnchen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6826-5801","authenticated-orcid":false,"given":"Jani","family":"S\u00e4rkk\u00e4","sequence":"additional","affiliation":[{"name":"Finnish Meteorological Institute, FI-00101 Helsinki, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4219-0407","authenticated-orcid":false,"given":"Felix L.","family":"M\u00fcller","sequence":"additional","affiliation":[{"name":"Deutsches Geod\u00e4tisches Forschungsinstitut, Technische Universit\u00e4t M\u00fcnchen (DGFI-TUM), 80333 M\u00fcnchen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4741-3449","authenticated-orcid":false,"given":"Christian","family":"Schwatke","sequence":"additional","affiliation":[{"name":"Deutsches Geod\u00e4tisches Forschungsinstitut, Technische Universit\u00e4t M\u00fcnchen (DGFI-TUM), 80333 M\u00fcnchen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J\u00e9r\u00f4me","family":"Benveniste","sequence":"additional","affiliation":[{"name":"European Space Agency-ESRIN, Largo Galileo Galilei, I-00044 Frascati, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,22]]},"reference":[{"key":"ref_1","first-page":"1","article-title":"Satellite Altimetry","volume":"Volume 69","author":"Fu","year":"2001","journal-title":"Satellite Altimetry and Earth Sciences: A Handbook of Techniques and Applications"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Stammer, D., and Cazenave, A. 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