Ultra light UAV systems for the metrical documentation of cultural heritage: Applications for architecture and archaeology

The Italian legislation on Remote Pilot Aircraft Systems (SAPR: Sistema Areomobile a Pilotaggio Remoto), as in 2012, regulates the use of drones in controlled and uncontrolled airspace. In 2016, the regulation introduced simplified procedures for the use of ultralight drones. These instruments are particularly widespread in the field of Cultural Heritage survey. In fact, according to the Italian regulations currently in force it is possible to pilot a drone of less than 300 grams without the need of a flight license and without a specific training course and medical examination and it is not required a special permit to fly in populates areas (although without flying over groups of people). Another possible explanation is the limited cost of these aircrafts and their easy availability on the market, both on the shelves of all electronic shops and in online stores. Following the boom of drones under 300 g, and considering the new European regulations also pay particular attention to a similar segment of Unmanned Aerial Vehicle (UAV) (in the future for aircraft under 250 g), it is important to evaluate the results that can be obtained through these small instruments and above all to evaluate which are the fields of application compatible with the technical limitations imposed by the need to lighten the components onboard (think in particular of the sensors of digital cameras). The purpose of the study is linked to the documentation of Cultural Heritage, in particular, we want to investigate the quality and metric reliability of photogrammetric surveys carried out through ultra-light drone images. Some application of UAV photogrammetry by ultra-light drones are showed in this paper and they deal with archaeological and architectural survey.