Improved ASCAT Wind Retrieval Using NWP Ocean Calibration

7 pages, 6 figures, 1 table

Detalles Bibliográficos
Autores: Verspeek, Jeroen, Stoffelen, Ad, Verhoef, Anton, Portabella, Marcos
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/71969
Acceso en línea:http://hdl.handle.net/10261/71969
Access Level:acceso abierto
Palabra clave:Calibration
Radar scattering
Scatterometer
Wind
Backscatter
Maximum likelihood estimation
Sea measurements
Wind speed
id ES_8ea012043f5135ee005e841d77b5afe2
oai_identifier_str oai:digital.csic.es:10261/71969
network_acronym_str ES
network_name_str España
repository_id_str
spelling Improved ASCAT Wind Retrieval Using NWP Ocean CalibrationVerspeek, JeroenStoffelen, AdVerhoef, AntonPortabella, MarcosCalibrationRadar scatteringScatterometerWindBackscatterCalibrationMaximum likelihood estimationSea measurementsWind speed7 pages, 6 figures, 1 tableThe Advanced Scatterometer (ASCAT) wind data processor (AWDP) currently uses the so called CMOD5n geophysical model function (GMF), which was originally derived for the European Remote Sensing (ERS) scatterometers. In order to deliver a high-quality ASCAT wind product, the operational AWDP uses backscatter measurement corrections that are estimated visually (VOC) for each wind vector cell. We propose an alternative and previously established method for estimating correction tables based on numerical weather prediction ocean calibration residuals (NOC). It embodies a smooth incidence-angle dependent part that could serve as an appropriate ASCAT GMF correction, and a radar-beam-dependent residual. The incidence-angle-dependent part of these correction tables is due to differences in calibration procedure of the ERS and ASCAT scatterometers. For the high ASCAT incidence angles for which the GMF has not been assessed by ERS data, the modification is quite large, almost 1 dB. The incidence angle-dependent part is derived by fitting the OC residuals of all beams obtained over one year of data. It is subsequently used to adapt the GMF (yielding CMOD5na). The remaining radar-beam-dependent residual (NOCa) shows a wiggle pattern as function of incidence angle that is very persistent over time, apart from a seasonally varying offset. Both the effects of the GMF modification and the beam-dependent residual on the wind retrieval quality are investigated in this paper. Overall, the performance of NOC is better than that obtained with the previously used VOC calibration method, and the wind statistics show a much better symmetry of the left and right swath for NOC. The beam-dependent corrections improve the quality of the retrieved winds. NOC may thus be used for the intercalibration of the ERS and ASCAT scatterometersThe authors wish to thank their colleagues from EUMETSAT and KNMI, Craig Anderson, Hans Bonekamp, Julia Figa and Jur Vogelzang, for their interest in this work, stimulating discussions, provision of data and helpful advice. Footnote: This work is done in the framework of the Ocean and Sea Ice Satellite Application Facility (OSI SAF) and its visiting scientist scheme. The ASCAT winds produced at KNMI can be obtained free of charge from the OSI SAF web site. AWDP has been funded by EUMETSAT in the context of the NWP SAF and can be obtained free of charge from the NWP SAF web site (Helpdesk: scat@knmi.nl)Peer reviewedInstitute of Electrical and Electronics EngineersConsejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]201320132012info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501http://hdl.handle.net/10261/71969reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttps://doi.org/10.1109/TGRS.2011.2180730Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/719692026-05-22T06:33:51Z
dc.title.none.fl_str_mv Improved ASCAT Wind Retrieval Using NWP Ocean Calibration
title Improved ASCAT Wind Retrieval Using NWP Ocean Calibration
spellingShingle Improved ASCAT Wind Retrieval Using NWP Ocean Calibration
Verspeek, Jeroen
Calibration
Radar scattering
Scatterometer
Wind
Backscatter
Calibration
Maximum likelihood estimation
Sea measurements
Wind speed
title_short Improved ASCAT Wind Retrieval Using NWP Ocean Calibration
title_full Improved ASCAT Wind Retrieval Using NWP Ocean Calibration
title_fullStr Improved ASCAT Wind Retrieval Using NWP Ocean Calibration
title_full_unstemmed Improved ASCAT Wind Retrieval Using NWP Ocean Calibration
title_sort Improved ASCAT Wind Retrieval Using NWP Ocean Calibration
dc.creator.none.fl_str_mv Verspeek, Jeroen
Stoffelen, Ad
Verhoef, Anton
Portabella, Marcos
author Verspeek, Jeroen
author_facet Verspeek, Jeroen
Stoffelen, Ad
Verhoef, Anton
Portabella, Marcos
author_role author
author2 Stoffelen, Ad
Verhoef, Anton
Portabella, Marcos
author2_role author
author
author
dc.contributor.none.fl_str_mv Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Calibration
Radar scattering
Scatterometer
Wind
Backscatter
Calibration
Maximum likelihood estimation
Sea measurements
Wind speed
topic Calibration
Radar scattering
Scatterometer
Wind
Backscatter
Calibration
Maximum likelihood estimation
Sea measurements
Wind speed
description 7 pages, 6 figures, 1 table
publishDate 2012
dc.date.none.fl_str_mv 2012
2013
2013
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
format article
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/71969
url http://hdl.handle.net/10261/71969
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv https://doi.org/10.1109/TGRS.2011.2180730
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Institute of Electrical and Electronics Engineers
publisher.none.fl_str_mv Institute of Electrical and Electronics Engineers
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869413144213848064
score 15,812429

Similares en LA Referencia