978 research outputs found
Dual-PEEC Modeling of a Two-Port TEM Cell for VHF Applications
Two-port TEM cells with rectangular cross section are commonly used to produce plane electromagnetic waves with high electric field. The non-uniform structure makes the use of numerical methods extremely useful in the design phase in order to achieve a very good behavior of the TEM cell over a wide frequency range of operation. In this paper an extended version of PEEC is used to study a real device and results are compared with experimental ones
GEOMATIC TECHNIQUES FOR THE OPTIMIZATION OF SKI RESOURCES
Climate change is already affecting the entire world, with extreme weather conditions such as drought, heat waves, heavy rain, floods and landslides becoming more frequent, including Europe. In according to Paris agreement and relative European announcement of Carbon neutrality (by 2050), the saving of water and energy supplies is a fundamental aspect in the management of resources in production, sports, hospitality facilities and so on. Some methodologies for the optimization of the consumption of natural resources are required. This article describes an activity aimed at measuring, monitoring and analysing the thickness of the snowpack on the ski slopes during the winter season to permit a sustainable approach of snowmaking in alpine ski areas . The authors propose a methodology based on the integration of multitemporal surface (ground/snow) survey by Autonomous Aerial Vehicle (AAV) and low cost GNSS receivers mounted on snow groomers for a RTK (Real Time Kinematic) solution. To obtain a complete snow surface digital models with poor detailed images on ski slopes, some pre-processing techniques have been analysed to locally improve contrast and details with a local high pass filtering. The methodology has been employed in two study areas (Limone Piemonte, Prato Nevoso) located in the province of Cuneo, in the southern alpine area of Piedmont
UP4DREAM CAPACITY BUILDING PROJECT: UAS BASED MAPPING IN DEVELOPING COUNTRIES
UP4DREAM (UAV Photogrammetry for Developing Resilience and Educational Activities in Malawi) is a cooperative project cofounded by ISPRS between the Polytechnic University of Turin and the United Nations Children Fund (UNICEF) Malawi, with the support of two local Universities (Lilongwe University of Agriculture and Natural Resources, and Mzuzu University), and Agisoft LLC (for the use of their photogrammetry and computer vision software suite). Malawi is a flood-prone landlocked country constantly facing natural and health challenges, which prevent the country's sustainable socio-economic development. Frequent naturals shocks leave vulnerable communities food insecure. Moreover, Malawi suffers from high rates of HIV, as well as it has endemic malaria. The UP4DREAM project focuses on one of the drone project's critical priorities in Malawi (Imagery). It aims to start a capacity-building initiative in line with other mapping missions in developing countries, focusing on the realization and management of large-scale cartography (using GIS - Geographic Information Systems) and on the generation of 3D products based on the UAV-acquired data. The principal aim of UP4DREAM is to ensure that local institutions, universities, researchers, service companies, and manufacturers operating in the humanitarian drone corridor, established by UNICEF in 2017, will have the proper knowledge and understanding of the photogrammetry and spatial information best practices, to perform large-scale aerial data acquisition, processing, share and manage in the most efficient, cost-effective and scientifically rigorous way
Performance of six functionals (LDA, PBE, PBESOL, B3LYP, PBE0 and WC1LYP) in the simulation of vibrational and dielectric properties of crystalline compounds. The case of forsterite Mg2SiO4
The performance of six different density functionals (LDA, PBE, PBESOL, B3LYP, PBE0, and WC1LYP) in describing the infrared spectrum of forsterite, a crystalline periodic system with orthorhombic unit cell (28 atoms in the primitive cell, Pbmn space group), is investigated by using the periodic ab initio CRYSTAL09 code and an all-electron Gaussian-type basis set. The transverse optical (TO) branches of the 35 IR active modes are evaluated at the equilibrium geometry together with the oscillator strengths and the high-frequency dielectric tensor 8. These quantities are essential to compute the dielectric function ϵ(ν), and then the reflectance spectrum R(v), which is compared with experiment. It turns out that hybrid functionals perform better than LDA and GGA, in general; that B3LYP overperforms WC1LYP and, in turn, PBE0; that PBESOL is better than PBE; that LDA is the worst performing functional among the six under study
Tephrochronology in faulted Middle Pleistocene tephra layer in the Val d’Agri area (Southern Italy)
The High Agri River Valley is a Quaternary Basin located along the hinge of the Southern Apennines fold-andthrust
belt. The inner margin of the orogen has been affected by intense transtensional and normal faulting, which
accompanied vigorous volcanism during the Quaternary. Marker tephra layers are distributed across the whole of
Southern Italy and provide a powerful tool to constrain both the size of eruptions and the regional activity of extensional
faults controlling basin evolution. Paleoseismological trenching within the Monti della Maddalena
range, that borders the Agri River Valley to the south-west, has exposed a faulted stratigraphic sequence and recovered
a 10 cm thick tephra layer involved in deformation. This is the first tephra horizon recognized in the high
Agri Valley, which, based on the stratigraphic study of the trench, lies in a primary position. 40Ar/39Ar dating
constrain its age to 266 ka and provide an important marker for the Middle Pleistocene tephrochronology of the
region. Together with dating, geochemical analysis suggests a possible volcanic source in the Campanian region
TLS MODELS GENERATION ASSISTED BY UAV SURVEY
By now the documentation and 3D modelling activities of built heritage concern in an almost usual way terrestrial Lidar techniques (TLS, Terrestrial Laser Scanning), and large scale mapping derived by UAV (Unmanned Aerial Vehicle) survey. This paper refers an example of 3D survey and reality based modelling applied on landscape and architectural assets. The choice of methods for documentation, in terms of survey techniques, depends primarily on issues and features of the area.
The achieved experience, allow to consider that the easy handling of TLS has enabled the use in limited spaces among buildings and collapsed roofs, but the topographic measure of GCPs (Ground Control Points), neither by total station nor by GPS/RTK technique, was easily feasible. Even more than proving the ability of the integration of TLS and UAV photogrammetry to achieve a multi-source and multi-scale whole model of a village, the experience has been a test to experiment the registration of terrestrial clouds with the support of control points derived by UAV survey and finally, a comparison among different strategies of clouds registration is reported. Analysing for each approach a number of parameters (number of clouds registration, number of needed points, processing time, overall accuracy) the further comparisons have been achieved.
The test revealed that it is possible to decrease the large number of terrestrial control points when their determination by topographical measures is difficult, and it is possible to combine the techniques not only for the integration of the final 3Dmodel, but also to solve and make the initial stage of the drafting process more effective
Propriedades físico-hídricas e índice de qualidade dos solos no distrito de irrigação tabuleiros litorâneos do Piauí.
O objetivo desta pesquisa foi diagnosticar as propriedades físico-hídricas como granulometria, densidade do solo, água disponível às culturas, índice de degradação física dos solos, bem como os teores de matéria orgânica do Distrito de Irrigação Tabuleiros Litorâneos do Piauí, em Parnaíba, PI..
GEOMATIC TECHNIQUES FOR THE OPTIMIZATION OF SKI RESOURCES
Abstract. Climate change is already affecting the entire world, with extreme weather conditions such as drought, heat waves, heavy rain, floods and landslides becoming more frequent, including Europe. In according to Paris agreement and relative European announcement of Carbon neutrality (by 2050), the saving of water and energy supplies is a fundamental aspect in the management of resources in production, sports, hospitality facilities and so on. Some methodologies for the optimization of the consumption of natural resources are required. This article describes an activity aimed at measuring, monitoring and analysing the thickness of the snowpack on the ski slopes during the winter season to permit a sustainable approach of snowmaking in alpine ski areas . The authors propose a methodology based on the integration of multitemporal surface (ground/snow) survey by Autonomous Aerial Vehicle (AAV) and low cost GNSS receivers mounted on snow groomers for a RTK (Real Time Kinematic) solution. To obtain a complete snow surface digital models with poor detailed images on ski slopes, some pre-processing techniques have been analysed to locally improve contrast and details with a local high pass filtering. The methodology has been employed in two study areas (Limone Piemonte, Prato Nevoso) located in the province of Cuneo, in the southern alpine area of Piedmont
DIRECT GEOREFERENCING APPROACHES FOR CLOSE-RANGE AND UAV PHOTOGRAMMETRY IN THE BUILT HERITAGE DOMAIN
Direct georeferencing uses onboard sensors to measure the position and orientation of the camera during image acquisition for photogrammetric applications. This approach aims to eliminate the use of traditional Ground Control Points (GCPs) in the photogrammetric process in order to reduce the costs and the time of the survey operations. The direct georeferencing technique involves integrating measurements from inertial measurement units (IMUs) and Global Navigation Satellite Systems (GNSS) data in order to evaluate the position and attitude of the camera with high accuracy (a few centimeters). In the Built Heritage survey domain, this approach is mainly followed by the employment of UAVs (Uncrewed aerial systems) platforms that are nowadays equipped with highly accurate systems able to evaluate the external parameters for the photogrammetric process. For terrestrial applications, few already achieved tests were performed; moreover, the sensors today available for extracting information from close-range acquisition systems are limited and sometimes under development. To evaluate the possibility offered by these new direct georeferencing tools, a test on the 3D ImageVector (REDcatch GmbH) has been performed. The results and the strategies followed will be presented and analyzed in order to understand better the accuracy and the potentiality of this new promising approach
Training of Crisis Mappers and Map Production from Multi-sensor Data: Vernazza Case Study (Cinque Terre National Park, Italy)
This aim of paper is to presents the development of a multidisciplinary project carried
out by the cooperation between Politecnico di Torino and ITHACA (Information
Technology for Humanitarian Assistance, Cooperation and Action). The
goal of the project was the training in geospatial data acquiring and processing for
students attending Architecture and Engineering Courses, in order to start up a
team of “volunteer mappers”. Indeed, the project is aimed to document the environmental
and built heritage subject to disaster; the purpose is to improve the capabilities
of the actors involved in the activities connected in geospatial data collection,
integration and sharing. The proposed area for testing the training
activities is the Cinque Terre National Park, registered in the World Heritage List since 1997. The area was affected by flood on the 25th of October 2011. According
to other international experiences, the group is expected to be active after
emergencies in order to upgrade maps, using data acquired by typical geomatic
methods and techniques such as terrestrial and aerial Lidar, close-range and aerial
photogrammetry, topographic and GNSS instruments etc.; or by non conventional
systems and instruments such us UAV, mobile mapping etc. The ultimate goal is
to implement a WebGIS platform to share all the data collected with local authorities
and the Civil Protection
- …