{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/34749"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/34749","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Study of the Origins of the Sigma-0 Blooms","abstract":"The TOPEX/POSEIDON Project is a joint U.S. and French mission to develop and operate an Earth orbiting satellite capable of making accurate measurements of the mean sea level in a way that allows the study of ocean dynamics. The understanding of ocean dynamics is very important in order to study events such as El Nino. Soon after the launch of the TOPEX satellite, some unusually high, but localized, values of the ocean's radar cross section, sigma-0, were observed by scientists at the NASA Goddard Space Flight Center. These phenomena have been referred to as sigma-0 blooms, and are accompanied by an increase in noise in the significant wave height (SWH) and altitude measurements. Since approximately 5% of all data recorded by the satellite contains sigma-0 blooms, it is important to understand their causes so that corrective measures can be taken by NASA. This thesis investigates two possible origins of the sigma-0 blooms: a surface containing a step discontinuity in sigma-0, and a surface containing slick or calm areas. Models corresponding to the theoretical returns from these two types of surfaces are developed and studied.","abstract_html":"The TOPEX/POSEIDON Project is a joint U.S. and French mission to develop and operate an Earth orbiting satellite capable of making accurate measurements of the mean sea level in a way that allows the study of ocean dynamics. The understanding of ocean dynamics is very important in order to study events such as El Nino. Soon after the launch of the TOPEX satellite, some unusually high, but localized, values of the ocean's radar cross section, sigma-0, were observed by scientists at the NASA Goddard Space Flight Center. These phenomena have been referred to as sigma-0 blooms, and are accompanied by an increase in noise in the significant wave height (SWH) and altitude measurements. Since approximately 5% of all data recorded by the satellite contains sigma-0 blooms, it is important to understand their causes so that corrective measures can be taken by NASA. This thesis investigates two possible origins of the sigma-0 blooms: a surface containing a step discontinuity in sigma-0, and a surface containing slick or calm areas. Models corresponding to the theoretical returns from these two types of surfaces are developed and studied.","abstract_has_math":false,"creators":["Garcia, Albert"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Electrical and Computer Engineering","degree_department":"Electrical and Computer Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Brown, Gary S."],"committee_members":["Safaai-Jazi, Ahmad","Pratt, Timothy J."],"year":1999,"date_issued":"1999-06-17","date_published":"1999-06-17","updated_at":"2026-07-22T22:18:46Z","subjects":["radar altimetry","TOPEX","sigma-0 blooms"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-082499-164532"],"render_values":[{"text":"etd-082499-164532","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/34749","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Brown, Gary S."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Safaai-Jazi, Ahmad","Pratt, Timothy J."]},{"key":"dc:contributor.department","label":"Department","values":["Electrical and Computer Engineering"]},{"key":"dc:creator","label":"Author","values":["Garcia, Albert"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:44:09Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:44:09Z","2000-08-27"]},{"key":"dc:date.issued","label":"Date","values":["1999-06-17"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical and Computer Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["radar altimetry","TOPEX","sigma-0 blooms"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-082499-164532"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/34749"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The TOPEX/POSEIDON Project is a joint U.S. and French mission to develop and operate an Earth orbiting satellite capable of making accurate measurements of the mean sea level in a way that allows the study of ocean dynamics. The understanding of ocean dynamics is very important in order to study events such as El Nino. Soon after the launch of the TOPEX satellite, some unusually high, but localized, values of the ocean's radar cross section, sigma-0, were observed by scientists at the NASA Goddard Space Flight Center. These phenomena have been referred to as sigma-0 blooms, and are accompanied by an increase in noise in the significant wave height (SWH) and altitude measurements. Since approximately 5% of all data recorded by the satellite contains sigma-0 blooms, it is important to understand their causes so that corrective measures can be taken by NASA. This thesis investigates two possible origins of the sigma-0 blooms: a surface containing a step discontinuity in sigma-0, and a surface containing slick or calm areas. Models corresponding to the theoretical returns from these two types of surfaces are developed and studied."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Study of the Origins of the Sigma-0 Blooms"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Brown, Gary S."],"dc:contributor.committeemember":["Safaai-Jazi, Ahmad","Pratt, Timothy J."],"dc:contributor.department":["Electrical and Computer Engineering"],"dc:creator":["Garcia, Albert"],"dc:date.accessioned":["2014-03-14T20:44:09Z"],"dc:date.available":["2014-03-14T20:44:09Z","2000-08-27"],"dc:date.issued":["1999-06-17"],"dc:description.abstract":["The TOPEX/POSEIDON Project is a joint U.S. and French mission to develop and operate an Earth orbiting satellite capable of making accurate measurements of the mean sea level in a way that allows the study of ocean dynamics. 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