Water volume variations in Lake Izabal (Guatemala) from in situ measurements and ENVISAT Radar Altimeter (RA-2) and Advanced Synthetic Aperture Radar (ASAR) data products

2010 ◽  
Vol 382 (1-4) ◽  
pp. 34-48 ◽  
Author(s):  
Camilo Medina ◽  
Jesus Gomez-Enri ◽  
Jose Juan Alonso ◽  
Pilar Villares
Keyword(s):  
Synthetic Aperture Radar ◽  
In Situ Measurements ◽  
Synthetic Aperture ◽  
Water Volume ◽  
Radar Altimeter ◽  
Data Products ◽  
Aperture Radar

scholarly journals Assessment of DUACS Sentinel-3A Altimetry Data in the Coastal Band of the European Seas: Comparison with Tide Gauge Measurements

2020 ◽  
Vol 12 (23) ◽  
pp. 3970
Author(s):  
Antonio Sánchez-Román ◽  
Ananda Pascual ◽  
Marie-Isabelle Pujol ◽  
Guillaume Taburet ◽  
Marta Marcos ◽  
...  
Keyword(s):  
Synthetic Aperture Radar ◽  
Tide Gauge ◽  
Synthetic Aperture ◽  
Altimetry Data ◽  
Radar Altimeter ◽  
Long Wave ◽  
Tide Gauge Measurements ◽  
European Seas ◽  
Aperture Radar

The quality of the Data Unification and Altimeter Combination System (DUACS) Sentinel-3A altimeter data in the coastal area of the European seas is investigated through a comparison with in situ tide gauge measurements. The comparison was also conducted using altimetry data from Jason-3 for inter-comparison purposes. We found that Sentinel-3A improved the root mean square differences (RMSD) by 13% with respect to the Jason-3 mission. In addition, the variance in the differences between the two datasets was reduced by 25%. To explain the improved capture of Sea Level Anomaly by Sentinel-3A in the coastal band, the impact of the measurement noise on the synthetic aperture radar altimeter, the distance to the coast, and Long Wave Error correction applied on altimetry data were checked. The results confirmed that the synthetic aperture radar altimeter instrument onboard the Sentinel-3A mission better solves the signal in the coastal band. Moreover, the Long Wave Error processing contributes to reduce the errors in altimetry, enhancing the consistency between the altimeter and in situ datasets.

scholarly journals DESCRIPCIÓN DEL PROYECTO DE TESIS DOCTORAL: APLICACIÓN DE LA TECNOLOGIA DINSAR A LA PREVENCION DE LOS RIESGOS GEOLOGICOS NATURALES E INDUCIDOS EN CIUDADES E INFRAESTRUCTURAS PRIORITARIAS DE CENTROAMÉRICA

2021 ◽  
Author(s):  
Carlos García-Lanchares ◽  
Miguel Marchamalo ◽  
Candela Sancho
Keyword(s):  
Costa Rica ◽  
Synthetic Aperture Radar ◽  
El Salvador ◽  
Synthetic Aperture ◽  
Earth Surface ◽  
Differential Interferometry ◽  
Surface Monitoring ◽  
Aperture Radar

Este documento presenta la formulación y primeros pasos de un proyecto de Doctorado Industrial, desarrollado en elmarco del proyecto Kuk ahpán que tiene como objetivo comprender, monitorear y modelar procesos tectónicos a escalalitosférica en Centroamérica. Para ello, un equipo internacional de seis países (Nicaragua, Costa Rica, El Salvador,Guatemala, Noruega y España) trabaja integrando la investigación en diversas técnicas e ingenierías Geofísicas, con elobjetivo de actualizar los Mapas de Riesgo Sísmico de la Región, un insumo crítico. para los códigos de seguridad yconstrucción. El proyecto de doctorado propuesto se enmarca en la investigación y desarrollo de tecnologías para prevenirlos riesgos geológicos naturales e inducidos que afectan a ciudades e infraestructuras en países altamente vulnerables,utilizando la tecnología DInSAR (Differential Interferometry with Synthetic Aperture Radar) optimizada por la startupDetektia Earth Surface Monitoring en colaboración con la Universidad Politécnica de Madrid. La interferometría diferencialde radar de apertura sintética es una técnica basada en el procesamiento y análisis de series largas de imágenes de radarde apertura sintética. Esta tecnología proporciona registros (desde 1992) y movimientos actualizados en cualquiersuperficie en cualquier parte del mundo sin necesidad de instrumentación terrestre, con precisiones de alrededor de 1 mm/ año (velocidad). En este contexto, el radar satelital proporciona información valiosa sobre áreas muy grandes quecomplementan el trabajo de campo y la instrumentación in situ. Primero, comenzamos integrando datos DInSAR condiversos datos geofísicos como batimetría, geomagnetismo, gravimetría, perfiles sísmicos… para mapear completamentela falla Swan sobre Honduras y Guatemala. Usamos esta tecnología para abordar el riesgo sísmico sobre la falla y áreascercanas. En un segundo paso, aplicaremos esta evaluación de riesgo sísmico (incluyendo amenazas naturales yantropogénicas) en ciudades e infraestructuras críticas en Centroamérica.

Monitoring spring phenology in Mediterranean beech populations through in situ observation and Synthetic Aperture Radar methods

2020 ◽  
Vol 248 ◽  
pp. 111978
Author(s):  
Roberta Proietti ◽  
Serena Antonucci ◽  
Maria Cristina Monteverdi ◽  
Vittorio Garfì ◽  
Marco Marchetti ◽  
...  
Keyword(s):  
Synthetic Aperture Radar ◽  
Synthetic Aperture ◽  
In Situ Observation ◽  
Spring Phenology ◽  
Aperture Radar

scholarly journals Evaluation of the Performances of Radar and Lidar Altimetry Missions for Water Level Retrievals in Mountainous Environment: The Case of the Swiss Lakes

2021 ◽  
Vol 13 (11) ◽  
pp. 2196
Author(s):  
Frédéric Frappart ◽  
Fabien Blarel ◽  
Ibrahim Fayad ◽  
Muriel Bergé-Nguyen ◽  
Jean-François Crétaux ◽  
...  
Keyword(s):  
Synthetic Aperture Radar ◽  
Water Level ◽  
Open Loop ◽  
Water Levels ◽  
Synthetic Aperture ◽  
Low Resolution ◽  
Radar Altimetry ◽  
Constant Bias ◽  
Aperture Radar

Radar altimetry is now commonly used to provide long-term monitoring of inland water levels in complement to or for replacing disappearing in situ networks of gauge stations. Recent improvements in tracking and acquisition modes improved the quality the water retrievals. The newly implemented Open Loop mode is likely to increase the number of monitored water bodies owing to the use of an a priori elevation, especially in hilly and mountainous areas. The novelty of this study is to provide a comprehensive evaluation of the performances of the past and current radar altimetry missions according to their acquisition (Low Resolution Mode or Synthetic Aperture Radar) and tracking (close or open loop) modes, and acquisition frequency (Ku or Ka) in a mountainous area where tracking losses of the signal are likely to occur, as well as of the recently launched ICESat-2 and GEDI lidar missions. To do so, we evaluate the quality of water level retrievals from most radar altimetry missions launched after 1995 over eight lakes in Switzerland, using the recently developed ALtimetry Time Series software, to compare the performances of the new tracking and acquisition modes and also the impact of the frequency used. The combination of the Open Loop tracking mode with the Synthetic Aperture Radar acquisition mode on SENTINEL-3A and B missions outperforms the classical Low Resolution Mode of the other missions with a lake observability greater than 95%, an almost constant bias of (−0.17 ± 0.04) m, a RMSE generally lower than 0.07 m and a R most of the times higher than 0.85 when compared to in situ gauge records. To increase the number of lakes that can be monitored and the temporal sampling of the water level retrievals, data acquired by lidar altimetry missions were also considered. Very accurate results were also obtained with ICESat-2 data with RMSE lower than 0.06 and R higher than 0.95 when compared to in situ water levels. An almost constant bias (0.42 ± 0.03) m was also observed. More contrasted results were obtained using GEDI. As these data were available on a shorter time period, more analyses are necessary to determine their potential for retrieving water levels.

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