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Publicações

Publicações por CRIIS

2016

POTENTIAL OF SENTINEL-1A FOR NATION-WIDE ROUTINE UPDATES OF ACTIVE LANDSLIDE MAPS

Autores
Lazecky, M; Comut, FC; Nikolaeva, E; Bakon, M; Papco, J; Ruiz Armenteros, AM; Qin, Y; de Sousa, JJM; Ondrejka, P;

Publicação
XXIII ISPRS CONGRESS, COMMISSION VII

Abstract
Slope deformation is one of the typical geohazards that causes an extensive economic damage in mountainous regions. As such, they are usually intensively monitored by means of modern expertise commonly by national geological or emergency services. Resulting landslide susceptibility maps, or landslide inventories, offer an overview of areas affected by previously activated landslides as well as slopes known to be unstable currently. Current slope instabilities easily transform into a landslide after various triggering factors, such as an intensive rainfall or a melting snow cover. In these inventories, the majority of the existing landslide-affected slopes are marked as either stable or active, after a continuous investigative work of the experts in geology. In this paper we demonstrate the applicability of Sentinel-1A satellite SAR interferometry (InSAR) to assist by identifying slope movement activity and use the information to update national landslide inventories. This can be done reliably in cases of semi-arid regions or low vegetated slopes. We perform several analyses based on multitemporal InSAR techniques of Sentinel-1A data over selected areas prone to landslides.

2016

Subsidence monitoring in Seville (S Spain) using multi-temporal InSAR

Autores
Ruiz Armenteros, AM; Ruiz Constán, A; Lamas Fernández, F; Galindo Zaldívar, J; Sousa, JJ; De Galdeano, CS; Delgado, JM; Pedrera Parias, A; Martos Rosillo, S; Gil, AJ; Caro Cuenca, M; Hanssen, RF;

Publicação
European Space Agency, (Special Publication) ESA SP

Abstract
Seville, with a metropolitan population of about 1.5 million, is the capital and largest city of Andalusia (S Spain). It is the 30th most populous municipality in the European Union and contains three UNESCO World Heritage Sites. The Seville harbour, located about 80 km from the Atlantic Ocean, is the only river port in Spain. The city is located on the plain of the Guadalquivir River. Using Multi-Temporal InSAR with ERS-1/2 and Envisat data a subsidence behavior is detected in the period 1992-2010. The geometry of the subsiding areas suggests that it should be conditioned by the fluvial dynamics of the Guadalquivir River and its tributaries. Facies distribution along the fluvial system (paleochannels, flood plains.), with different grain size and matrix proportion, may explain the relative subsidence between the different sectors.

2016

Multi-Temporal InSAR processing comparison in presence of high topography

Autores
Ruiz Armenteros, AM; Bakon, M; Lazecky, M; Delgado, JM; Sousa, JJ; Perissin, D; Caro Cuenca, M;

Publicação
INTERNATIONAL CONFERENCE ON ENTERPRISE INFORMATION SYSTEMS/INTERNATIONAL CONFERENCE ON PROJECT MANAGEMENT/INTERNATIONAL CONFERENCE ON HEALTH AND SOCIAL CARE INFORMATION SYSTEMS AND TECHNOLOGIES, CENTERIS/PROJMAN / HCIST 2016

Abstract
In this paper we compare the results obtained by three different InSAR tool packages, StaMPS, SARPROZ and P-SBAS (CNR-IREA) on G-POD for the processing of a mountainous area with up to 2,000 m high differences. For that we use two dataset ERS-1/2 and Envisat ASAR. The area (Sierra Tejeda, southern Spain) is located close to the coast line in the Internal Zone of the Betic Cordillera. The recent NW-SE convergence of the Eurasian-African plate boundary makes this area to belong to a large fold which continues active up to present. The uplift of the mountain ranges is mainly related to the development of folds in this regional compressive setting. This paper investigates and compares the velocity pattern obtained by the three different algorithms to help to constraint the geological hazard in this part of the Betic Cordillera. (C) 2016 The Authors. Published by Elsevier B.V.

2016

A DATA MINING APPROACH FOR MULTIVARIATE OUTLIER DETECTION IN HETEROGENEOUS 2D POINT CLOUDS: AN APPLICATION TO POST-PROCESSING OF MULTI-TEMPORAL INSAR RESULTS

Autores
Bakon, M; Oliveira, I; Perissin, D; Sousa, J; Papco, J;

Publicação
2016 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM (IGARSS)

Abstract
Thresholding on coherence is a common practice for identifying the surface scatterers that are less affected by decorrelation noise during post-processing and visualisation of the results from multi-temporal InSAR techniques. Simple selection of the points with coherence greater than a specific value is, however, challenged by the presence of spatial dependence among observations. If the discrepancies in the areas of moderate coherence share similar behaviour, it appears important to take into account their spatial correlation for correct inference. Low coherence areas thus could serve as clear indicators of measurement noise or imperfections in mathematical models. Once exhibiting properties of statistical similarity, they allow for detection of observations that could be considered as outliers and trimmed from the dataset. In this paper we propose an approach based on renowned data mining and exploratory data analysis procedures for mitigating the impact of outlying observations in the final results.

2016

Potential of C-Band SAR Interferometry for Dam Monitoring

Autores
Sousa, JJ; Ruiz, AM; Bakon, M; Lazecky, M; Hlavacova, I; Patricio, G; Manuel Delgado, JM; Perissin, D;

Publicação
INTERNATIONAL CONFERENCE ON ENTERPRISE INFORMATION SYSTEMS/INTERNATIONAL CONFERENCE ON PROJECT MANAGEMENT/INTERNATIONAL CONFERENCE ON HEALTH AND SOCIAL CARE INFORMATION SYSTEMS AND TECHNOLOGIES, CENTERIS/PROJMAN / HCIST 2016

Abstract
Despite the recent popularity achieved by the modern X-band SAR sensors, mainly due to their high spatial resolutions which enable the detection of deformation components impossible so far, such as thermal expansion, SAR C-band sensors continue to be of great utility and with a great future in the deformation monitoring field, namely for critical structure monitoring, such as dams. The new ESA missions (Sentinel-1A and 1B) and the extension of the Canadian Radarsat mission corroborate this finding. In this paper the possibility of using spacebome SAR sensors for dam monitoring is addressed in terms of feasibility and applications. The presented results show the potential of C-band sensors for the particular case of dam monitoring and can be handful to recognize the applicability of new Sentinel-1 data (since 2014) for continuous monitoring of dam deformations. (C) 2016 The Authors. Published by Elsevier B.V.

2016

Subsidence monitoring in the coastal region of Nigeria using multi temporal interferometric synthetic aperture radar (MT-Insar)

Autores
Mahmud, MU; Yakubu, TA; Adewuyi, TO; Sousa, JJ; Ruiz Armenteros, AM; Bakon, M; Lazecky, M; Perissin, D;

Publicação
European Space Agency, (Special Publication) ESA SP

Abstract
The uncontrolled exploitation of the groundwater, oil and gas in the Nigerian coastal geosyncline has led to progressive decline of the aquifer level and a continuous need for opening deeper drillings to exploit deeper aquifers. From the analysis of the interferometric results derived from the application of Multi-Temporal Interferometry (MT-InSAR) technique, Lagos state appears to be subsiding conically up to -7 mm/yr. The velocity rates of subsidence in the surrounding cities like Lekki, Badagry, Ikorodu and Epe are much higher than in Lagos city. These preliminary investigation results reveal heavy structures, in particular buildings, that were seen constructed mostly on the sand filled areas where the sediments compaction rates is very high.

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