Détail de l'auteur
Auteur Alvaro Santamaria Gomez
Commentaire :
PhD student at LAREG (2007-2010)
idRef :
ORCID :
Scopus :
G. Scholar :
DBLP URL :
|
Documents disponibles écrits par cet auteur (13)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externesCoastal sea level and related fields from existing observing systems / Marta Marcos in Surveys in Geophysics, vol 40 n° 6 (November 2019)
Titre : Coastal sea level and related fields from existing observing systems Type de document : Article/Communication Auteurs : Marta Marcos, Auteur ; Guy Wöppelmann Année de publication : 2019 Article en page(s) : pp 1293 - 1317 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Amérique du nord
[Termes IGN] données marégraphiques
[Termes IGN] Europe (géographie politique)
[Termes IGN] littoral
[Termes IGN] niveau de la merRésumé : (auteur) We review the status of current sea-level observing systems with a focus on the coastal zone. Tide gauges are the major source of coastal sea-level observations monitoring most of the world coastlines, although with limited extent in Africa and part of South America. The longest tide gauge records, however, are unevenly distributed and mostly concentrated along the European and North American coasts. Tide gauges measure relative sea level but the monitoring of vertical land motion through high-precision GNSS, despite being essential to disentangle land and ocean contributions in tide gauge records, is only available in a limited number of stations. (25% of tide gauges have a GNSS station at less than 10 km.) Other data sources are new in situ observing systems fostered by recent progress in GNSS data processing (e.g., GPS reflectometry, GNSS-towed platforms) and coastal altimetry currently measuring sea level as close as 5 km from the coastline. Understanding observed coastal sea level also requires information on various contributing processes, and we provide an overview of some other relevant observing systems, including those on (offshore and coastal) wind waves and water density and mass changes. Numéro de notice : A2019-278 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10712-019-09513-3 Date de publication en ligne : 05/02/2019 En ligne : https://doi.org/10.1007/s10712-019-09513-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95411
in Surveys in Geophysics > vol 40 n° 6 (November 2019) . - pp 1293 - 1317[article]
Titre : Levelling co-located GNSS and tide gauge stations using GNSS reflectometry Type de document : Article/Communication Auteurs : Alvaro Santamaria Gomez, Auteur ; Christopher S. Watson, Auteur ; Médéric Gravelle, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 241 - 258 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse comparative
[Termes IGN] erreur systématique
[Termes IGN] étalonnage d'instrument
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] marée océanique
[Termes IGN] marégraphe
[Termes IGN] nivellement
[Termes IGN] point de liaison (géodésie)
[Termes IGN] propagation troposphérique
[Termes IGN] rapport signal sur bruit
[Termes IGN] réflectance de surface
[Termes IGN] réflectométrie par GNSS
[Termes IGN] signal GPSRésumé : (auteur) The GNSS reflectometry technique provides geometric information on the environment surrounding the GNSS antenna including the vertical distance to a reflecting surface. We use sea-surface reflections of GPS signals, recorded as oscillations in signal-to-noise ratio (SNR), to estimate the GNSS to tide gauge (TG) levelling tie, and thus the ellipsoidal heights of the TG. We develop approaches to isolate SNR data dominated by sea-surface reflections and to remove SNR frequency changes caused by the dynamic sea surface. Comparison with in situ levelling at eight sites reveals mean differences at the centimetre level for satellites above 12∘ elevation, with four sites showing differences of 3 cm or smaller. These differences include errors in the in situ levelling, in the antenna calibration model and in the TG measurements, and so represent an upper bound on our technique’s error. Data sampling (1 or 30 s) does not significantly affect the results. We detect systematic errors at the decimetre level related to satellite elevations below 12∘ and to sea-surface height and also differences between results from the L1 and L2 GPS signals larger than 15 cm at two sites. These systematic errors remain unexplained; differences between GPS signals are attributed to receiver-dependent differences in the SNR measurements, while the elevation-dependent error is attributed to unmodelled phase effects such as those caused by tropospheric refraction and sea-surface roughness. Using our approach, we identify a levelling offset of 1.5 cm related to a TG sensor change, illustrating our technique’s value for TG reference monitoring. Numéro de notice : A2015-337 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0784-y Date de publication en ligne : 20/12/2014 En ligne : https://doi.org/10.1007/s00190-014-0784-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76705
in Journal of geodesy > vol 89 n° 3 (March 2015) . - pp 241 - 258[article]
Titre : Long-term vertical land motion from double-differenced tide gauge and satellite altimetry data Type de document : Article/Communication Auteurs : Alvaro Santamaria Gomez, Auteur ; Médéric Gravelle, Auteur ; Guy Wöppelmann Année de publication : 2014 Article en page(s) : pp 207 - 222 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] altimétrie
[Termes IGN] déformation verticale de la croute terrestre
[Termes IGN] marée océanique
[Termes IGN] marégraphie
[Termes IGN] positionnement par GPSRésumé : (Auteur) We present a new approach to estimate precise long-term vertical land motion (VLM) based on double-differences of long tide gauge (TG) and short altimetry data. We identify and difference rates of pairs of highly correlated sea level records providing relative VLM estimates that are less dependent on record length and benefit from reduced uncertainty and mitigated biases (e.g. altimeter drift). This approach also overcomes the key limitation of previous techniques in that it is not geographically limited to semi-enclosed seas and can thus be applied to estimate VLM at TGs along any coast, provided data of sufficient quality are available. Using this approach, we have estimated VLM at a global set of 86 TGs with a median precision of 0.7 mm/year in a conventional reference frame. These estimates were compared to previous VLM estimates at TGs in the Baltic Sea and to estimates from co-located Global Positioning System (GPS) stations and Glacial Isostatic Adjustment (GIA) predictions. Differences with respect to the GPS and VLM estimates from previous studies resulted in a scatter of around 0.6 mm/year. Differences with respect to GIA predictions had a larger scatter in excess of 1 mm/year. Until satellite altimetry records reach enough length to estimate precise VLM at each TG, this new approach constitutes a substantial advance in the geodetic monitoring of TGs with major applications in long-term sea level change and climate change studies. Numéro de notice : A2014-132 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0677-5 Date de publication en ligne : 08/12/2013 En ligne : https://doi.org/10.1007/s00190-013-0677-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33037
in Journal of geodesy > vol 88 n° 3 (March 2014) . - pp 207 - 222[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2014031 SL Revue Centre de documentation Revues en salle Disponible
contenu dans Reference frames for applications in geosciences, Proceedings of IAG Symposium REFAG 2010 / Zuheir Altamimi (2013)
Titre : Time-correlated GPS noise dependency on data time period Type de document : Article/Communication Auteurs : Alvaro Santamaria Gomez, Auteur ; Marie-Noëlle Bouin Editeur : Berlin, Heidelberg, Vienne, New York, ... : Springer Année de publication : 2013 Collection : International Association of Geodesy Symposia, ISSN 0939-9585 num. 138 Conférence : REFAG 2010, Reference Frames for Applications in Geosciences, IAG symposium 04/10/2010 08/10/2010 Champs-sur-Marne France Proceedings Springer Importance : pp 119 - 124 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] analyse diachronique
[Termes IGN] bruit (théorie du signal)
[Termes IGN] filtrage du bruit
[Termes IGN] positionnement par GPS
[Termes IGN] série temporelleRésumé : (Auteur) GPS position time series contain time-correlated noise. The estimated parameters using correlated time series data, as station velocities, are then more uncertain than if the time series data were uncorrelated. If the level of the time-correlated noise is not taken into account, the estimated formal uncertainties will be smaller. By estimating the type and amplitude of the noise content in time series, more realistic formal uncertainties can be assessed. However, time-correlated noise amplitude is not constant in long time series, but depends on the time period of the time series data. Older time series data contain larger time-correlated noise amplitudes than newer time series data. This way, shorter time series with older data time period exhibit time-correlated noise amplitudes similar to the whole time series. This paper focuses on the source of the time-correlated noise amplitude decrease from older to newer time series period data. The results of several tested sources are presented. Neither the increasing ambiguity fixation rate, nor the increasing number of tracking stations, nor the increasing number of observed satellites are likely the source of the noise reduction. The quality improvement of the equipment of both tracking network and constellation is likely the main source of the correlated noise evolution. Numéro de notice : C2010-015 Affiliation des auteurs : LAREG (1991-2011) Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.1007/978-3-642-32998-2_19 Date de publication en ligne : 27/11/2012 En ligne : http://dx.doi.org/10.1007/978-3-642-32998-2_19 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=65070
Titre : Mitigating the effects of vertical land motion in tide gauge records using a state-of-the-art GPS velocity field Type de document : Article/Communication Auteurs : Alvaro Santamaria Gomez, Auteur ; Médéric Gravelle, Auteur ; Xavier Collilieux Année de publication : 2012 Article en page(s) : pp 6 - 17 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altimétrie satellitaire par radar
[Termes IGN] champ de vitesse
[Termes IGN] déformation verticale de la croute terrestre
[Termes IGN] données GPS
[Termes IGN] données marégraphiques
[Termes IGN] montée du niveau de la mer
[Termes IGN] niveau de la mer
[Termes IGN] série temporelleRésumé : (Auteur) This study aims to correct for long-term vertical land motions at tide gauges (TG) by estimating high-accurate GPS vertical velocities at co-located stations (GPS@TG), useful for long-term sea-level change studies and satellite altimeter drift monitoring. Global Positioning System (GPS) data reanalyses are mandatory when aiming at the highest consistency of the estimated products for the whole data period. The University of La Rochelle Consortium (ULR) has carried out several GPS data reanalysis campaigns with an increasing tracking network, an improving processing strategy and the best methodology. The geodetic results from the latest GPS velocity field estimated at ULR (named ULR5) are presented here. The velocity field includes 326 globally distributed GPS stations, from which 200 are GPS@TG (30% more than previous studies). The new GPS data processing strategy, the terrestrial frame definition and the velocity estimation procedures are described. The quality of the estimated vertical velocities is empirically assessed through internal and external velocity comparisons, including the analysis of the time-correlated noise content of the position time series, to be better than 0.6 mm/yr (2 sigma). The application of this velocity field is illustrated to appraise to what extent vertical land motions contaminate the estimates of satellite altimetry drifts. The impact on the altimeter-derived sea level trends was evaluated to be up to 0.6 mm/yr. Worldwide TGs were grouped into regions in order to explore long-term spatial sea level variability in the rates of sea level change. By taking into account the vertical land motion of the tide gauges, the dispersion of the observed sea level rates within each region was reduced by 60%. Long-term regional mean sea level variations up to 70% from the global mean were found. Numéro de notice : A2012-741 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.gloplacha.2012.07.007 Date de publication en ligne : 26/07/2012 En ligne : https://doi.org/10.1016/j.gloplacha.2012.07.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91477
in Global and Planetary Change > vol 98 - 99 (December 2012) . - pp 6 - 17[article]
PermalinkPermalinkPermalinkEstimation of crustal vertical movements with GPS in a geocentric frame, within the framework of the TIGA project / Alvaro Santamaria Gomez (2010)
Permalink
