Consulta: subjectFacets:"Geodesy"
Registros recuperados: 6
Data/hora: 09/06/2024 06:05:12

The Benefits of the Ka-Band as Evidenced from the SARAL/AltiKa Altimetric Mission: Scientific Applications
Provedor de dados: 5
Autores: Verron, Jacques; Bonnefond, Pascal; Aouf, Lofti; Birol, Florence; Bhowmick, Suchandra A.; Calmant, Stephane; Conchy, Taina; Cretaux, Jean-francois; Dibarboure, Gerald; Dubey, A. K.; Faugere, Yannice; Guerreiro, Kevin; Gupta, P. K.; Hamon, Mathieu; Jebri, Fatma; Kumar, Raj; Morrow, Rosemary; Pascual, Ananda; Pujol, Marie-isabelle; Remy, Elisabeth; Remy, Frederique; Smith, Walter H. F.; Tournadre, Jean; Vergara, Oscar.
The India-France SARAL/AltiKa mission is the first Ka-band altimetric mission dedicated primarily to oceanography. The mission objectives were firstly the observation of the oceanic mesoscales but also global and regional sea level monitoring, including the coastal zone, data assimilation, and operational oceanography. SARAL/AltiKa proved also to be a great opportunity for inland waters applications, for observing ice sheet or icebergs, as well as for geodetic investigations. The mission ended its nominal phase after three years in orbit and began a new phase (drifting orbit) in July 2016. The objective of this paper is to highlight some of the most remarkable achievements of the SARAL/AltiKa mission in terms of scientific applications. Compared to the...
Tipo: Text
Palavras-chave: Altimetry; Ka-band; Oceanography; Hydrology; Ice; Geodesy.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00600/71248/69623.pdf

Comparing the role of absolute sea-level rise and vertical tectonic motions in coastal flooding, Torres Islands (Vanuatu)
Provedor de dados: 5
Autores: Ballu, Valerie; Bouin, Marie-noelle; Simeoni, Patricia; Crawford, Wayne C.; Calmant, Stephane; Bore, Jean-michel; Kanas, Tony; Pelletier, Bernard.
Since the late 1990s, rising sea levels around the Torres Islands (north Vanuatu, southwest Pacific) have caused strong local and international concern. In 2002-2004, a village was displaced due to increasing sea incursions, and in 2005 a United Nations Environment Programme press release referred to the displaced village as perhaps the world's first climate change "refugees." We show here that vertical motions of the Torres Islands themselves dominate the apparent sea-level rise observed on the islands. From 1997 to 2009, the absolute sea level rose by 150 +/- 20 mm. But GPS data reveal that the islands subsided by 117 +/- 30 mm over the same time period, almost doubling the apparent gradual sea-level rise. Moreover, large earthquakes that occurred just...
Tipo: Text
Palavras-chave: Geodesy; Seismic cycle; Island arcs; Vertical motion.
Ano: 2011
URL: https://archimer.ifremer.fr/doc/00144/25575/23734.pdf

Evidence for a differential sea level rise between hemispheres over the twentieth century
Provedor de dados: 5
Autores: Woeppelmann, Guy; Marcos, Marta; Santamaria-gomez, Alvaro; Martin-miguez, Belen; Bouin, Marie-noelle; Gravelle, Mederic.
Tide gauge records are the primary source of sea level information over multidecadal to century timescales. A critical issue in using this type of data to determine global climate-related contributions to sea level change concerns the vertical motion of the land upon which the gauges are grounded. Here we use observations from the Global Positioning System for the correction of this vertical land motion. As a result, the spatial coherence in the rates of sea level change during the twentieth century is highlighted at the local and the regional scales, ultimately revealing a clearly distinct behavior between the Northern and the Southern Hemispheres with values of 2.0mm/yr and 1.1mm/yr, respectively. Our findings challenge the widely accepted value of...
Tipo: Text
Palavras-chave: Sea level; Climate change; Land motion; Geodesy; Tide gauge; GPS.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00489/60025/63282.pdf

Densification of the Ground-Based GNSS Observation Network in the Southwest Indian Ocean: Current Status, Perspectives, and Examples of Applications in Meteorology and Geodesy
Provedor de dados: 5
Autores: Bousquet, Olivier; Lees, Edouard; Durand, Jonathan; Peltier, Aline; Duret, Anne; Mekies, Dominique; Boissier, Patrice; Donal, Thomas; Fleischer-dogley, Frauke; Zakariasy, Lova.
In the frame of the research project IOGA4MET, a new ground-based GNSS network is being deployed in the Southwest Indian Ocean (SWIO) since November 2017. This new network opens up for new research opportunities in geodesics and atmospheric sciences in this area regularly exposed to natural hazards, and significantly expands the International GNSS System (IGS) network, which only includes eight stations so far in the SWIO. After a description of the current status of IOGA4MET, several examples of regional applications in meteorology (climatology and numerical modeling) and geodesy (monitoring of ground deformations) are presented using data collected in northern Madagascar and small neighboring islands in 2018–2020. The observed water vapor cycle is shown...
Tipo: Text
Palavras-chave: Southwest Indian Ocean; GNSS - Global Navigation Satellite System; Water vapor cycle; Madagascar; Mayotte; Geodesy; NWP (numerical weather prediction); AROME Indian Ocean.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00651/76324/77302.pdf

Trabajos geodésicos realizados durante la II Expedición Ecuatoriana hacia la Antártida en Punta Fort Williams-Isla Greenwich
Provedor de dados: 20
Autores: Urbina, G.; Arciniegas, S.; Ruano, M.
El presente proyecto marca el inicio de los trabajos geodésicos del Ecuador en el continente Antártico, y nació por la necesidad de contar con una base de partida para establecer el fotocontrol necesario para obtener la restitución aerofotogramétrica del sector, base para la edición de una carta naútica como aporte a la seguridad en la navegación. Abarca un sector donde no existen sondeos realizados por otros países.
Tipo: Journal Contribution
Palavras-chave: Geodesy; Marine geodesy; Aerial photography; Aerial photography; Geodesy; Http://aims.fao.org/aos/agrovoc/c_8634; Http://aims.fao.org/aos/agrovoc/c_3228.
Ano: 1990
URL: http://hdl.handle.net/1834/3730

Determinación del datum vertical en La Libertad, Ecuador
Provedor de dados: 20
Autores: Paredes, N.
Normalmente en los levantamientos geodésicos se utilizan dos tipos de referencias: las coordenadas de origen y el datum vertical: Las primeras están en función del elipsoide o superficie matemática de referencia que más se ajusta al área, y el segundo; por la determinación del nivel medio del mar con 19 años de observación. El Ecuador tiene como elipsoide de referencia, el Internacional y el datum horizontal del punto localizado en la Canoa, Venezuela (Provisional South American Datum 1956, PSAD 56), cuya coordenadas han sido transportadas a nuestro país mediante redes geodésicas. En 1948, el Ecuador instaló una estación mareográfica en la Libertad (Lat. 020° 12'S., Long. 80° 55'W) y a la determinación del datum vertical se refiere el presente trabajo.
Tipo: Journal Contribution
Palavras-chave: Datum levels; Geodesy; Geodesy; Http://aims.fao.org/aos/agrovoc/c_3228.
Ano: 1986
URL: http://hdl.handle.net/1834/2154