3d Photogrammetric Restitution of Carvings and GIS Applies. The case of the Fontana of Nettuno at Conegliano Veneto.

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3d Photogrammetric Restitution of Carvings and GIS Applies. The case of the Fontana of Nettuno at Conegliano Veneto.

Technical Appendix: Phases of the survey
I. Topographic network: it has been made a external topographical network (Fig. 1) composed from 4 points ground-marked along 2 main radials regarding the carving group.
Used instrument: total station T2000 Wild with high-precision EDM Wild DISTOMAT 2000 and prism reflector.
Precision: angular measurement 0.1 mgon (0.3"); distance 1 mm + 1 ppm (with prism).

II. Control points to support photogrammetric survey: approximately 300 control points have been taken from vertex of network to support operations of photogrammetric restitution: internal and external orientation of model, creation of rectified digital images.
Used instrument: total station SOKKIA Power set 2000 with 1 cm target plate.
Precision: angular measurement 0.5 mgon (1.5"); distance 1 mm ± 3 ppm (with target), 2 mm ± 2 ppm (with prism).
SQM control points (with target plate): "x" 0.17 mm, " y" 0.9 mm, "z" 0.41 mm.

III. Carving group topographical survey with laser scanning device: points on head of Nettuno have been taken with a 5 cm grid pass; approximately 2500 points have been taken from 4 control points of principal network (fig 3); XYZ coordinates have been referred to a single coordinate system and loaded to a CAD as point entity to obtain a "three-dimensional cloud" of carving group (Fig. 4).
Used instrument: motorized total station reflectorness TCRM 1101 1100 (TPS 1100).
Precision: angular measurement 0.5 mgon (1.5"); distance 3 mm ± 2 ppm (no prism), 2 mm ± 2 ppm (with prism).
SQM surveyed points (standard deviation): "x" 0.18 mm, " y" 2.87 mm, "z" 0.98 mm.

IV Photogrammetrical survey: digital calibrated camera Nikon E2 (resolution 1280 x 1000 pixel - optical aperture f/6.7 f/38) has been used to the takes of tank of fountain and carving group.
For all the 12 sides of fountain has been realized a rectified digital images (omographic processing - figg. 5/6). Also has been realized a partial digital ortophoto of left side of the carving (Fig. 7).
Used software: Menci - Nikon Stereoview (old release).

GIS
Today is increasing the opportunities offered in the data acquisition and in the processing of the same thank to the use of the advanced methodologies and technology: topographic survey of vertical sections and surfaces of the manufacts with total station no prism, the agile acquisition of images (metric, semi-metric and not calibrated cameras, digital and not digital), the simplified methodologies of survey and the digital photogrammetric restitution obtained through digital Software. It has been explained the logical structures and models set up through relational data bank in order to create different archives of data: the aim is the data management to support the different phases of the project of conservation and of the Cataloguing of the monuments or objects in the museums: The intervention become the natural outcome of the levels of the single and related knowledge, and the GIS can be the natural basin to document the history of the carving, not only during the past but also in the future, recording the phases of the restoration process, the alteration and changes in the time.

GIS technology can be used to support both these fields applied from the architectural scale to the urban scale to support the production of the map of the risk of the Cultural Architectonic Heritage. GIS can be really used as decision support system to set up a project of conservation which satisfy the necessity to relate heterogeneous information, which come from different disciplines, to the decision processes the analysis of the materials (Fig. 10), the state of the art, the state of degree of the marbles and of the components of the carving (Fig. 11), the analysis of the causes of degree, disruption, the decay, weathering and deterioration, the studies of the different pathologies. Once mapped the degree on the raster metric images, on the different portions, in future it has to be increased the research to set up an easy metric surface 3D computation implementing GIS functionality and consequently an agile computation of the costs, related to 3D DSM (3D surfaces model). GIS can be also a valid instrument to support in real time the daily activity in the architectural yard. The organization of dedicated data bank allows verifying the standard limits admitted by the low in the re-use project. It has been used the Software ArcInfo and ArcView to build the GIS system, and the Software ArcExplorer to share and use the information, distributed by ESRI. It can become a valid instrument to support in real time the daily activity in the architectural yard.

Guide lines for the development of the research

Implementation of survey through laser scanning technology applied to the carving;
Implementation TIN 3D model with auto-correlation test;
Implementation of Digital Surface Model (DSM) intelligent and automatic recognizing ;
3D orthophoto generation;
3D GIS management of the raste-vector model to better support conservation process and yard intervention.

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