Search results for "DSA"
showing 10 items of 87 documents
Monitoring displacements of an earthen dam using GNSS and remote sensing
2014
This paper shows the results of a scientific research in which a GNSS continuous monitoring system for earth-dam deformations has been developed, then, deformations have been related with reservoir water surface and level. The experiment was conducted near Bivona (Sicily, Italy), on the Castello dam (Magazzolo Lake). On the top of the dam three control points were placed and three GNSS permanent stations were installed. The three stations continuously transmitted data to the control centre of the University of Palermo. The former has been determined using freely available satellite data (specifically Landsat 7 SLC-Off) collected during the whole study period (DOYs 101 to 348 2011). Issues r…
Detection of a reservoir water level using shape similarity metrics
2017
The matching between reservoirs’ water edge and digital elevation model’s (DEM) contour lines allowed determining the water level at the acquisition date of satellite images. A preliminary study was conducted on the Castello dam (Magazzolo Lake), between Alessandria della Rocca and Bivona (Agrigento, south-Italy). The accuracy assessment of the technique was than evaluated from the comparison between classified and reference objects using similarity metrics about the shape, theme, edge and position, through the plugin STEP of open source software GIS. Moreover, an independent GIS technique was implemented to evaluate the water level, based on a distances’ array between existing contour line…
Impact of Land Cover Change Induced by a Fire Event on the Surface Energy Fluxes Derived from Remote Sensing
2015
Forest fires affect the natural cycle of the vegetation, and the structure and functioning of ecosystems. As a consequence of defoliation and vegetation mortality, surface energy flux patterns can suffer variations. Remote sensing techniques together with surface energy balance modeling offer the opportunity to explore these changes. In this paper we focus on a Mediterranean forest ecosystem. A fire event occurred in 2001 in Almodovar del Pinar (Spain) affecting a pine and shrub area. A two-source energy balance approach was applied to a set of Landsat 5-TM and Landsat 7-EMT+ images to estimate the surface fluxes in the area. Three post-fire periods were analyzed, six, seven, nine, and 11 y…
Coupling SAR X-band and optical data for NDVI retrieval: model calibration and validation on two test areas
2013
Sustainability of modern agro-hydrology requires the knowledge of spatial and temporal variability of vegetation biomass to optimize management of land and water resources. Diversely from optical imaging, temporal resolution of active sensors, such as SAR, is not limited by sky cloudiness; thus, they may be combined with optical imageries to provide a more continuous monitoring of land surfaces. Several new SAR missions (e.g., ALOS-PALSAR, COSMO-SkyMed 1 and 2, TerraSAR-X, TerraSAR-X2, Sentinel 1) acquiring at X-, C- and L-bands and dual polarization capability, are characterized by a short revisit time (from 12 h to ~10 days) and high spatial resolution (<20 m). These satellites could prov…
A Simple Fusion Method for Image Time Series Based on the Estimation of Image Temporal Validity
2015
High-spatial-resolution satellites usually have the constraint of a low temporal frequency, which leads to long periods without information in cloudy areas. Furthermore, low-spatial-resolution satellites have higher revisit cycles. Combining information from high- and low- spatial-resolution satellites is thought a key factor for studies that require dense time series of high-resolution images, e.g., crop monitoring. There are several fusion methods in the bibliography, but they are time-consuming and complicated to implement. Moreover, the local evaluation of the fused images is rarely analyzed. In this paper, we present a simple and fast fusion method based on a weighted average of two in…
Land surface temperature retrieval from LANDSAT TM 5
2004
In this paper, three methods to retrieve the land surface temperature (LST) from thermal infrared data supplied by band 6 of the Thematic Mapper (TM) sensor onboard the Landsat 5 satellite are compared. The first of them lies on the estimation of the land surface temperature from the radiative transfer equation using in situ radiosounding data. The others two are the mono-window algorithm developed by Qin et al. [International Journal of Remote Sensing 22 (2001) 3719] and the single-channel algorithm developed by Jime´nez-Mun˜oz and Sobrino [Journal of Geophysical Research 108 (2003)]. The land surface emissivity (LSE) values needed in order to apply these methods have been estimated from a…
Like barn leker mest, men er det best? : Integrering av enslige mindreårige gjennom fritidsaktiviteter
2016
Master thesis development management - University of Agder 2016
Effekter av systematisk opplæring i samtalepreget veiledning målt med en multippel basislinjedesign
2010
Accepted version of an article from the journal: Norsk Tidsskrift for Atferdsanalyse. Published version available from http://www.atferd.no/nta/ Det finnes få empiriske studier av om opplæring i samtalepreget veiledning har effekt i form av økte veiledningsferdigheter. På tross av manglende systematisk empiri, er opplæring i veiledning svært utbredt. I vår studie har vi operasjonalisert grunnleggende veiledningsferdigheter og utviklet et måleinstrument2 med totalt 11 variabler. Fem deltakere har gjennomgått et opplæringsprogram basert på basislinjemålinger, og effektene er målt med samme måleinstrumentet i en multippel basislinjedesign inkludert en oppfølgingsfase. Vi presenterer måleinstru…
Parādsaistību veidošanās iemesli un ietekmejošie faktori
2015
Maģistra darba mērķis ir noskaidrot parādsaistību veidošanās iemeslus un noteicošos faktorus. Maģistra darbs sastāv no trim nodaļām. Pirmajā nodaļā ir aplūkota un raksturota patēriņa sabiedrība kā parādsaistību veidošanās cēlonis, noskaidroti parādsaistību pieauguma ietekmējošie faktori. Otrajā nodaļā ir analizētas nedrošo kredītu apjomu izmaiņas ES dalībvalstīs, tajā skaitā kredītu atmaksas tendences Latvijā un izpētīta Latvijas makroekonomisko rādītāju un izmaiņas likumdošanas vidē ietekme uz parādsaistībām. Trešajā nodaļā tiek aprakstīts autores veiktais pētījums par parādsaistību veidošanās iemesliem un veicinošiem faktoriem un analizēti iegūtie dati. Maģistra darba galvenais secinājums…
Penser la prose pour chanter Athènes : quelques réflexions sur le langage dans le Panathénaïque d’Aelius Aristide
2022
Sans sous-estimer la place de la poésie dans la société hellénisée du Haut-Empire, on ne peut nier que la littérature grecque d’époque impériale soit dominée par l’écriture de la prose. L’orateur prend de plus en plus nettement la place du poète, dans un rapport qui revendique tout à la fois la continuité et la rivalité. La prose s’impose en acte, par la production des œuvres elles-mêmes, mais aussi à travers une réflexion sur sa propre nature, ses valeurs et la place à laquelle elle aspire f...