Methodological Report on Emergency Surveys for Cultural Heritage

The management of emergency scenario is a very complex issue, due to the risk of recurrence of the calamity itself. The present work is intended as a methodological report based on the gained professional and scientific experience of the authors, involved in the survey of several Cultural Heritage buildings hit by the earthquakes that afflicted Central Italy in 2016. The examined structures include the Civic Tower in Norcia, the co-cathedral Santa Maria Argentea and the San Salvatore church in Campi di Norcia. The survey campaigns were performed immediately after the aftershocks occurred in the end of October, on behalf of the Italian Ministry that at the time was called of Cultural Heritage and Activities and Tourism (MiBACT), in order to ease the securing of the sites and their restoration. Because of the necessity to provide the survey products as quickly as possible, typical in an emergency situation, particular attention was paid to optimize both the on-site and the post-processing phases, with respect to the required accuracy. In this regard, U.Ph.O. (Unmanned Photogrammetric Office), a tool developed during the Ph.D. thesis work of one of the authors, is particularly useful for the a priori evaluation of the realistic accuracy obtainable during a photogrammetric survey. In the present work, this tool was applied to the San Salvatore Church, taken as case study to check the influence on the photogrammetric products of two of the main planning parameters: the image overlapping and the accuracy in Unmanned Aerial Vehicle (UAV) positioning.