Traditional and modern methods of surveying architectural heritage: a few examples in the fortified island of Malta.

The problem of the renewal and rehabilitation of the impressive fortifications system of the Republic of Malta has led the Maltese government to operate in the framework of a far-reaching international cultural and financial intervention. To this purpose a cooperation agreement was introduced between the Ministry for the Environment of Malta and the University of Bologna. To attain this objective a multidisciplinary approach is necessary. Different working groups must carry out specific actions concerning the acquisition of knowledge and execution of survey on one hand and the design and execution of the interventions on the other. In particular, the surveying activity is carried out at different levels: • execution of an aerial photogrammetric survey on a scale of 1:500 for a deeper knowledge of the entire intervention site; • experimentation of an operational terrestrial photogrammetric survey methodology for different types of objects; • topographical structural monitoring. The experimentation on a few examples which will be described on this paper has led to the collection of a considerable amount of metric information, thanks to the use of different topographic and photogrammetric techniques and instruments. An element of great interest is linked to the possibility that a precision numeric photogrammetric survey adequately oriented towards documentation concerning the restoration can support the decision-taking procedures and the operational phases of the restoration thus allowing interesting developments with a direct link with the cataloguing aspects.