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Un primo rilevamento del globo celeste di Mattheus Greuter è stato effettuato dallo scrivente nel 1994 con l’impiego di tecniche topografiche e fotogrammetriche tradizionali, prima delle operazioni di restauro che hanno restituito al mappamondo il suo aspetto originario. Nel mese di giugno di quest’anno è stato eseguito un secondo rilevamento con l’impiego delle tecniche più recenti (laser scanning, fotogrammetria digitale). Il confronto fra i due rilevamenti fornisce interessanti indicazioni per valutare l’evoluzione delle tecniche in questi quindici anni.

In this paper the theoretic and practical points of view about the applications of the modern digital airborne sensors in the photogrammetry and remote sensing fields are described. The first part of the paper describes the theoretic matter, the second one shows the first results regarding the carried out elaborations on an image of Palermo acquired by digital airborne sensor LH System ADS40. Besides the research has examined most of sides regarding the trilinear sensor and it has highlighted the capabilities and limitations respect to the traditional analogical system and the matricial CCD sensor.

In this paper, in order to evaluate the capability of several data, acquired by different sensors, some object-oriented classification tests have been carried out. In particular, the results obtained with two RGB ortophotos, acquired with traditional methodology, have been compared with the ones obtained with two QuickBird images and with the ones obtained by ADS40 pushbroom sensor. The object classification is based on two next steps: The classification to objects is based on two next steps: the decomposition of the whole image in dimension objects bigger than the pixel, procedure called segmentation, and the next classification with Fuzzy logic. This approach provides more reliable results with respect to the classification based on the pixels as it associates homogeneous objects on the basis of the information contained both in the objects themselves and their mutual relations. At last, the results obtained in the three cases have been compared through statistical methods necessary to evaluate the quality of the produced classifications. The comparison has been carried out through the comparing of the confusion matrixes produced on the basis of some samples extracted from the origin images. The used methodology is very useful for the monitoring and identification of landscape changes; in particular, in order to individuate the changes due to the anthropic pressure, a orthophoto, produced in 1979 by traditional techniques and two QuickBird images, acquired in 2002 and 2006 respectively and relative to the very naturalistic area have been elaborated.

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.

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.