Papers by Vincenzo Franco
Atti del Convegno Nazionale …, 2007
La realizzazione di una rete di stazioni permanenti GNSS (Global Navigational Satellite System) p... more La realizzazione di una rete di stazioni permanenti GNSS (Global Navigational Satellite System) per il tempo reale (NRTK -Network Real Time Kinematic) è di grande interesse per la comunità scientifica e riguarda numerose fasi di lavoro legate a tematiche e aspetti di vario genere. Il gruppo di ricerca del settore topografico del Dipartimento di Rappresentazione dell'Università di Palermo, nell'ambito delle proprie attività, ha progettato e ha realizzato una rete sperimentale di stazioni permanenti GNSS NRTK per la Sicilia occidentale. La rete, che attualmente è in fase di ultimazione per quanto riguarda la piena operatività, è costituita da sei stazioni permanenti GNSS dislocate nelle province di Palermo e Trapani. Il presente articolo descrive e affronta alcune delle problematiche riscontrate nel corso dell'attività di ricerca e relative allo studio preliminare e alla scelta dei siti, alla materializzazione delle stazioni, al funzionamento delle strumentazioni hardware e software, alla trasmissione dei dati; vengono inoltre considerati gli aspetti relativi all'inquadramento geodetico.
This paper describes the first results of a study, carried out within the national research progr... more This paper describes the first results of a study, carried out within the national research program "Cofin2001", on the potential use of high resolution satellite images for making digital orthophotos at a scale of 1:5000 and 1:10,000. Particularly, images from IKONOS II and QuickBird of four different types of areas were employed: the first area is the city of Palermo, a greatly urbanized area; the second area is the extra-urban territory near the town of Contessa Entellina in south-western Sicily; the third area is the famous tourist resort of Scopello, in the western Sicily; the last area is the Caselle Airport, a flat zone near Torino. The first three images were orthorectified by using Rational Functions Model (RFM), varying the number of the GCP and using a DEM with 10 m gridcell; the last image was orthorectified by using the Toutin model and a DEM with 40 m grid-cell.
Aerial photos, both in colour and in black and white, have always been very important tools in ar... more Aerial photos, both in colour and in black and white, have always been very important tools in archaeological surveys. Sensors, called hyperspectral, were available on the market for some years: they are able to expand the research beyond the visible area of the electromagnetic spectrum as far as the thermal infrared too. The use of these sensors, at first restricted to the applications in the traditional fields of Remote Sensing (such as, for instance, Botany, Agronomy, Geology, Hydrology), was spreading, in recent years, to some sectors, such as archaeological surveys, which were unexplored before. The presence of structures and hollows in the top subsurface is likely to cause variations in humidity in the surface. These variations affect both vegetation, and some physical features of the ground such as thermal conductivity and capacity. Especially in the first hours of day, you can notice thermal anomalies due to different evaporation. The exam of these anomalies, carried out by the use of techniques of digital processing of images in the spectrum bands particularly sensitive to the abovementioned indicators, enables the photointerpreter to determine possible signs of underground structures of archaeological interest. The application of the remote sensing in archaeology allows to acquire, with rapidity, a lot of information connected to the territory; that's the reason why, together with the development of sensors, came out the necessity to take advantage from the potentialities offered by the GIS to manage, process and file the spatial dates acquired with the remote sensing techniques. In this work, in fact, the results produced with the image processing technique were implemented in a GIS and were overlaid on the historical and contemporary maps and on the DEM in order to produce, for each study area, a Prediction map of archaeological finds.
The paper describes the first results of a study, supported by an Italian research project "Integ... more The paper describes the first results of a study, supported by an Italian research project "Integrated Inertial Positioning Systems in Aerial Photogrammetry" on the potential use of these techniques for production of digital large scale orthophotos. The study has been done with aerial photographs collected from two different flights executed in Sicily: the former, relating to the city of Palermo, at average scale of 1:9300; the latter, over the city of Catania, at average scale of 1:2000. For both flights the orthorectification was carried out by direct georeferencing methods and by traditional photogrammetric techniques, using ground control points surveyed by means GPS techniques and aerial digital triangulation. The orthophotos generated by both methods were compared between themselves checking the influence of integrated sensors on the accuracy of the final product.
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Papers by Vincenzo Franco