Digital photogrammetry: a useful tool for shipbuilding applications

In the shipbuilding field, the knowledge and representation of hulls and appendages, characterized by complex shapes, is a key need. Currently, different instruments and software can be used to obtain precise three-dimensional measurements. Active sensors such as laser scanners are the most common allowing quick and precise three-dimensional information, but at the same time, they are very costly. Photogrammetry is a cheaper and more flexible high precision survey technique than the laser scanner. Usually, the photogrammetric approach used for shipbuilding applications consists in measuring few points with high precision. An hybrid approach, that joins high-density automatic measurements and few targeted points together, is here presented. The results of a digital photogrammetric survey, performed on the 81-foot Italian Navy motor yacht “Argo”, are presented in this paper. A 3D reverse modelling methodology was applied in order to furnish reliable, high-accuracy measurements of the hull and the propeller screws.