Search results for "LIDAR"
showing 10 items of 475 documents
Community dimensions and emotions in the era of COVID-19
2021
Abstract Following an ecological perspective, reactions to a disaster—such as the COVID‐19 pandemic—should be analysed in the interdependence between individual and community dimensions. The present study aims to analyse individual emotional dimensions (anxiety, joy, fear or depressive feelings) and their community dimensions (connectedness, emotional sharing and solidarity) with a longitudinal approach among university students from Italian universities. Participants were 746 university students at t1 (during the lockdown) and 361 at t2 (after the lockdown) recruited in six Italian universities from different areas of Italy. Comparing emotional dimensions in the two times, t2 is characteri…
The PolarLITIS Dataset: Road Scenes Under Fog
2022
Road scene analysis is a fundamental task for both autonomous vehicles and ADAS systems. Nowadays, one can find autonomous vehicles that are able to properly detect objects in the scene in good weather conditions; however, some improvements still need to be done when the visibility is altered. People claim that using some non-conventional sensors such as, infra-red or Lidar, combined with classical vision, enhances road scene analysis in optimal weather conditions. In this work, we present the improvements achieved using polarimetric imaging in the complex situation of some adverse weather conditions. This rich modality is known for its ability to describe an object not only by its intensit…
Climatology of the aerosol extinction-to-backscatter ratio from sun-photometric measurements
2010
The elastic lidar equation contains two unknown atmospheric parameters, namely, the particulate optical extinction and backscatter coefficients, which are related through the lidar ratio (i.e., the particulate-extinction-to-backscatter ratio). So far, independent inversion of the lidar signal has been carried out by means of Raman lidars (usually limited to nighttime measurements), high-spectral-resolution lidars, or scanning elastic lidars under the assumption of a homogeneously vertically stratified atmosphere. In this paper, we present a procedure to obtain the lidar ratio at 532 nm by a combined Sunphotometer– aerosol-model inversion, where the viability of the solution is largely reinf…
Aerosol Lidar Intercomparison in the Framework of SPALINET—The Spanish Lidar Network: Methodology and Results
2009
Abstract—A group of eight Spanish lidars was formed in order to extend the European Aerosol Research Lidar Network–Advanced Sustainable Observation System (EARLINET-ASOS)project. This study presents intercomparisons at the hardware and software levels. Results of the system intercomparisons are based on range-square-corrected signals in cases where the lidars viewed the same atmospheres. Comparisons were also made for aeros backscatter coefficients at 1064 nm (2 systems) and 532 nm (all systems), and for extinction coefficients at 532 nm (2 systems). In total, three field campaigns were carried out between 2006 and 2007. Comparisons were limited to the highest layer found before the free tr…
Intercomparison of spanish advanced lidars in the framework of EARLINET
2007
To extend and reinforce the action of the EARLINET- ASOS project, a nucleus of Spanish advanced lidars was created. Four systems were intercompared satisfactorily in terms of backscatter coefficients at two elastic wavelengths. Peer Reviewed
Gestión tradicional de la escorrentía de tormentas para riego de prados en Monteagudo del Castillo (Teruel)
2021
espanolMonteagudo del Castillo (Teruel) esta cerca del polo de maxima tormentosidad violenta de la Peninsula Iberica. El aporte pluviometrico de estas tormentas es capaz de invertir el regimen estacional habitual del clima mediterraneo, con el verano como estacion mas lluviosa. Aqui se estudia la gestion tradicional de la arroyada en dos cuencas del termino municipal, desde la doble perspectiva riesgo/recurso: control de la erosion y aprovechamiento de la arroyada para regar prados. Para gestionar la arroyada concentrada de las tormentas se ha modificado la red de drenaje mediante acequias recolectoras y/o evacuadoras y la rectificacion de la red hidrografica natural. Las acequias de deriva…
Ideas and lives across the Atlantic. The American Anarchism in the Galician libertarian press
2019
In this article we will analyse, from a transnational history point of view, the presence of American anarchism in the Galician libertarian press until 1936. In the 19th and 20h centuries, the transatlantic migrations contributed to develop a dense network of contacts and relationships between Galicia and American countries. This network involves anarchist militants on both sides of the Ocean. The Galician anarchists have a close collaboration with her Americans libertarian comrades; and many Galician militants are actively committed in the labour movement of their host countries. The Galician libertarian press shows this relationship and this participation in different ways (articles, cont…
La giustizia valore supremo presso i Greci?
2020
Nella Grecia antica, la giustizia (il limitarsi passivamente a non fare il male e a rispettare i diritti altrui) è certamente un valore necessario ma spesso non è riconosciuto come valore sufficiente per la vita nella polis. Per tutta una linea di pensiero alla giustizia bisogna aggiungere, come integrazione indispensabile, la virtù attiva del curarsi degli altri. Altrimenti, si avrà un’aggregazione associativa, una somma di individui che si limitano a trattenersi dal compiere ingiustizia ma non si avrà comunità umana, che è solidarietà, ovvero aidós e philía, rispetto e amicizia In ancient Greece, justice (limiting oneself passively to respect the rights of others) is certainly a necessary…
A study of the effect of molecular and aerosol conditions in the atmosphere on air fluorescence measurements at the Pierre Auger Observatory
2010
The air fluorescence detector of the Pierre Auger Observatory is designed to perforin calorimetric measurements of extensive air showers created by Cosmic rays of above 10(18) eV. To correct these measurements for the effects introduced by atmospheric fluctuations, the Observatory contains a group Of monitoring instruments to record atmospheric conditions across the detector site, ail area exceeding 3000 km(2). The atmospheric data are used extensively in the reconstruction of air showers, and are particularly important for the correct determination of shower energies and the depths of shower maxima. This paper contains a summary of the molecular and aerosol conditions measured at the Pierr…
Comparison of aerosol size distributions measured at ground level and calculated from inversion of solar radiances
2005
Ground-based sunphotometry measurements can be used to investigate atmospheric aerosol optical properties, such as the volume size distribution, an important parameter in the study of the effect of aerosol on atmospheric processes. Most inversion algorithms assume constant aerosol optical characteristics over the whole air column. In this work we present observational evidence of the limitations of this simplifying assumption in cases where the aerosol vertical structure is highly inhomogeneous. During the field campaign VELETA 2002, carried out in Granada (Spain), a quite complete characterization of the atmospheric aerosol was obtained by simultaneously measuring the columnar aerosol char…