Search results for " Planetary"
showing 10 items of 5408 documents
Revision of the Single-Channel Algorithm for Land Surface Temperature Retrieval From Landsat Thermal-Infrared Data
2009
This paper presents a revision, an update, and an extension of the generalized single-channel (SC) algorithm developed by Jimenez-Munoz and Sobrino (2003), which was particularized to the thermal-infrared (TIR) channel (band 6) located in the Landsat-5 Thematic Mapper (TM) sensor. The SC algorithm relies on the concept of atmospheric functions (AFs) which are dependent on atmospheric transmissivity and upwelling and downwelling atmospheric radiances. These AFs are fitted versus the atmospheric water vapor content for operational purposes. In this paper, we present updated fits using MODTRAN 4 radiative transfer code, and we also extend the application of the SC algorithm to the TIR channel …
Temperature and Emissivity Separation From MSG/SEVIRI Data
2014
In this paper, we analyze the feasibility of applying the temperature and emissivity separation (TES) algorithm to thermal-infrared data acquired with three bands of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard the Meteosat Second Generation platform (SEVTES). The performance of the SEVTES algorithm was tested using data simulated over different atmospheric conditions and surface emissivities, with errors around 1.5% for emissivity and 1.5 K for temperature when atmospheric correction is accurate enough. In contrast, errors on land-leaving radiances higher than 2% or uncertainties on total atmospheric water vapor amount higher than 5% lead to errors on emissivity highe…
Polarization-driven spin precession of mesospheric sodium atoms
2018
We report experimental results on the first on-sky observation of atomic spin precession of mesospheric sodium driven by polarization modulation of a continuous-wave laser. The magnetic resonance was remotely detected from the ground by observing the enhancement of induced fluorescence when the driving frequency approached the precession frequency of sodium in the mesosphere, between 85 km and 100 km altitude. The experiment was performed at La Palma, and the uncertainty in the measured Larmor frequency ($\approx$260 kHz) corresponded to an error in the geomagnetic field of 0.4 mG. The results are consistent with geomagnetic field models and with the theory of light-atom interaction in the …
Dal game-based learning ai serious games: alcune prospettive per l’apprendimento mediato dalla tecnologia digitale
2023
In the last years, serious games have become popular in media education as they are useful tools in engaging, motivating, and helping students learn. However, few studies investigate the long-term effects of game-based learning, and many scholars declare themself skeptical about the learning mediated by digital technology. This paper reflects on the importance of new media and serious games for young people belonging to the Net Generation as defined by Prensky. In particular, I support the idea that game-based learning reflects a broader change in our society, coinciding with the rise of the phenomenon of Gamification and the Homo Ludens paradigm. Apart from the limitations of technology-me…
Database Versioning 2.0, a Transparent SQL Approach Used in Quantitative Management and Decision Making
2015
Abstract Managerial decisions are based on accurate information and in today's time raw data is produced even with a stroke of a key. Regardless of the data creating process one needs to know how the information was extracted and which pool of data was used. One important factor is time therefore we need to structure it in layers of data history in such a way that it can be analyzed, (post)process, in order to be able to retrieve valuable information. The simplest way is to use a Database Management System (DBMS), but even with such a management system we face the issue of making it a self-contained database on each version of data added. Our proposed system, a continuation of previous work…
Autocorrelation Metrics to Estimate Soil Moisture Persistence From Satellite Time Series: Application to Semiarid Regions
2021
Satellite-derived soil moisture (SM) products have become an important information source for the study of land surface processes in hydrology and land monitoring. Characterizing and estimating soil memory and persistence from satellite observations is of paramount relevance, and has deep implications in ecology, water management, and climate modeling. In this work, we address the problem of SM persistence estimation from microwave sensors using several autocorrelation metrics that, unlike traditional approaches, build on accurate estimates of the autocorrelation function from nonuniformly sampled time series. We show how the choice of the autocorrelation estimator can have a dramatic impac…
Avaluant la responsabilitat social universitària: el cas del centre de ciències humanes, socials i agràries de la Universitat Federal de Paraiba (Bra…
2019
espanolEl presente articulo, producido a partir de un estudio de caso, aborda la cuestion de la Responsabilidad Social Universitaria (RSU) en el Brasil. Basado en una Metodologia de Evaluacion da RSU, que busca identificar las evidencias objetivas sobre las acciones desarrolladas por las instituciones de educacion superior a partir de siete indicadores de Responsabilidad Social (inclusion social; desarrollo economico y social; defensa del medio ambiente; defensa del patrimonio y memoria cultural; defensa de la produccion artistica e defensa de la produccion deportiva y salud), se analizan las acciones concretas implantadas por el Centro de Ciencias Humanas, Sociales y Agrarias (CCHSA) da Un…
The sanitation service of seagrasses – Dependencies and implications for the estimation of avoided costs
2022
Seagrasses are capable of sanitizing coastal seawaters polluted by fecal bacteria. In this work, the reduction of Enterococci concentration in the presence of a seagrasses’ assemblage (Pacific Ocean) was related to the decrease in the probability of gastroenteritis. A linear model fitted to data extracted from the literature showed a 20% reduction of this probability in the presence of these plants. Seagrass sanitation effect was estimated to allow avoiding ca. 24 million gastroenteritis cases/year, globally. Considering a global cost of gastroenteritis of ca. US$ 372 million/year, the global avoided cost, assuming that the sanitation service was always effective, was estimated to be ca. US…
Evolution Within a Bizarre Phylum: Homologies of the First Echinoderms
1998
SYNOPSIS. The Extraxial/Axial Theory (EAT) of echinoderm skeletal homologies describes two major body wall types: axial and extraxial. The latter is subdivided into perforate and imperforate regions. Each of the regions has a distinctly different source in early larval development. Axial skeleton originates in the rudiment, and develops in association with the pentaradially arranged hydrocoel according to specific ontogenetic principles. Perforate and imperforate extraxial regions are associated with the left and right somatocoels respectively, are not governed by ontogenetic principles of plate addition, and are products of the non-rudiment part of the larval body. The morphology of even t…
Experimental system for the study of the directional thermal emission of natural surfaces
2004
A new automatic experimental system was designed to improve the accuracy of multidirectional thermal infrared measurements. This experimental system mainly consists of two identical thermal cameras operating at 8-13 mu m, one metal ring to keep the constant view area for different view angles and a goniometer, which is composed of: (1) a semicircular roadway of 2 m diameter to change the observation angle in the azimuth direction; (2) an elevator of 1 m height to adjust the measuring level to the target level; (3) a rotating arm equipped with one thermal camera for changing the observation angle in the zenith direction; and (4) a fixed arm equipped with another thermal camera to record at n…