Show simple item record

dc.contributor.authorCamps Carmona, Adriano José
dc.contributor.authorVall-Llossera Ferran, Mercedes Magdalena
dc.contributor.authorDuffo Ubeda, Núria
dc.contributor.authorTorres Torres, Francisco
dc.contributor.authorCorbella Sanahuja, Ignasi
dc.contributor.authorBatres Gonzalez, Luis
dc.contributor.otherUniversitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions
dc.date.accessioned2007-06-29T08:17:34Z
dc.date.available2007-06-29T08:17:34Z
dc.date.created2004
dc.date.issued2005-03-31
dc.identifier.citationCamps, A.; Vall-llossera, M.; Batres, L.; Duffo, N.; Torres, F.; Corbella, I. Retrieving sea surface salinity with multi-angular L-band brightness temperatures: improvement by spatiotemporal averaging. Radio science, 2005, vol. 40, núm. 2, p. 1-13
dc.identifier.issn0048-6604
dc.identifier.urihttp://hdl.handle.net/2117/1104
dc.description.abstractThe Soil Moisture and Ocean Salinity (SMOS) mission was selected in May 1999 by the European Space Agency to provide global and frequent soil moisture and sea surface salinity maps. SMOS' single payload is Microwave Imaging Radiometer by Aperture Synthesis (MIRAS), an L band two-dimensional aperture synthesis interferometric radiometer with multiangular observation capabilities. Most geophysical parameter retrieval errors studies have assumed the independence of measurements both in time and space so that the standard deviation of the retrieval errors decreases with the inverse of square root of the number of measurements being averaged. This assumption is especially critical in the case of sea surface salinity (SSS), where spatiotemporal averaging is required to achieve the ultimate goal of 0.1 psu error. This work presents a detailed study of the SSS error reduction by spatiotemporal averaging, using the SMOS end-to-end performance simulator (SEPS), including thermal noise, all instrumental error sources, current error correction and image reconstruction algorithms, and correction of atmospheric and sky noises. The most important error sources are the biases that appear in the brightness temperature images. Three different sources of biases have been identified: errors in the noise injection radiometers, Sun contributions to the antenna temperature, and imaging under aliasing conditions. A calibration technique has been devised to correct these biases prior to the SSS retrieval at each satellite overpass. Simulation results show a retrieved salinity error of 0.2 psu in warm open ocean, and up to 0.7 psu at high latitudes and near the coast, where the external calibration method presents more difficulties.
dc.format.extent1-13
dc.language.isoeng
dc.publisherAMER GEOPHYSICAL UNION
dc.subjectÀrees temàtiques de la UPC::Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Circuits de microones, radiofreqüència i ones mil·limètriques
dc.subject.lcshRadiometry
dc.subject.lcshCalibration
dc.subject.lcshSalinity
dc.subject.otherSalinity measurement
dc.subject.otherL-band
dc.subject.otherSea level
dc.subject.otherOceanography
dc.subject.otheraveraging
dc.subject.otherMoisture
dc.subject.otherSoils
dc.subject.otherThermal noise
dc.subject.otherGeophysics
dc.subject.otherRadiometers
dc.subject.otherInterferometers
dc.subject.otherImage reconstruction
dc.subject.otherCalibration
dc.subject.otherAlgorithms
dc.subject.otherComputer simulation
dc.subject.otherSoil moisture and ocean salinity
dc.subject.otherSea surface salinity
dc.subject.otherMicrowave imaging radiometer
dc.subject.otherImage reconstruction algorithms
dc.titleRetrieving Sea Surface Salinity With Multi-Angular L-band Brightness Temperatures: Improvement By Spatio-Temporal Averaging.
dc.typeArticle
dc.subject.lemacRadiometria
dc.subject.lemacCalibratge
dc.subject.lemacSalinitat
dc.contributor.groupUniversitat Politècnica de Catalunya. RF&MW - Grup de Recerca de sistemes, dispositius i materials de RF i microones
dc.description.peerreviewedPeer Reviewed
dc.rights.accessOpen Access
local.personalitzacitaciotrue


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record