## 3 The Joint Technical Activity: Emergency UAS-Based Aerial Photogrammetry
### Test Site Description and Concept of Operations  
The test site selected for the in situ application of rapid mapping, located between the municipalities of San Giorgio Bigarello and Castel Belforte (in province of Mantua in Italy--see Figure 3), is a large rectangular area (of about 450 ha) with a flat morphology and the possibility for the pilots to walk across in order to ensure that the VLOS (visual-line-of-sight) conditions are met (at the time of application, this is still a mandatory requirement). The total area has been mapped operating five UAS teams flying simultaneously on a sub-area of about 100 ha each, with a relative overlap of about 10-15% of the single sub-areas (see Figure 3). These sub-areas have been established based on the capabilities of each UAS and the input flight planning parameters reported in Table 1, considering that each team had to guarantee approximately one hour of continuous flight. On the same area, the survey exercise has been repeated twice, varying the typology of employed multi-rotors: UAS with maximum take-off mass (MTOM) < 2 kg (EXE 1) and UAS with 2 kg < MTOM < 25 kg (EXE 2). The location and flight parameters have been selected in order to comply with safety requirements. At the time of the exercises, according to the D-flight portal, in the area of interest there were no particular restrictions or authorization requirements, and the operations were allowed up to the maximum height of 120 m AGL. The overall on-site activity took place in two days, the 10 th and 11 th of October 2023, and involved a total of 35 participants from the Competence Centres of the Italian Civil Protection Department (listed in Section 1) and 11 multi-rotors (Figure 4). The weather conditions during all the days were generally favorable (good visibility and temperature around 20 \({}^{\circ}\)C). \begin{table}
\begin{tabular}{c c} \hline \hline  & **Flight Parameter** \\ \hline Flight height & 115–120 m AGL \\ Frontal and lateral image overlap & 80\% F–65–70\% L \\ Maximum velocity 1 & 7 m/s–9.7 m/s \\ Camera orientation & Nadiral \\ \hline \hline \end{tabular} \({}^{1}\)Set according to the UAS camera performance and the weather and illumination local conditions.  
\end{table} 
Table 1: Summary of the flight planning parameters set during EXE1 and EXE2. Figure 3: Target area selected for the rapid mapping activity, subdivided in five sub-areas. Source: Google Earth Pro. The mobile units of the National Research Council (CNR) and the EUCENTRE Foundation, located in a parking close to the area of survey and equipped with high-performance desktop workstations (e.g.,: EUCENTRE workstation: Intel(R) Core(TM) i7-9800X, CPU 3.8 GHz (Santa Clara, CA, USA), 32 GB RAM with Nvidia GeForce GTX 1080), have been employed as the on-site coordination base (CB, see Figures 3 and 5) for operations management, support battery charging (using external power generators), data processing and connection with the UAS CCT/CCOA. Given the surrounding environment (mostly agricultural non-urban area), for the purpose of the present exercise, particular safety precautions have been taken in order to keep the risk of the operation basically equivalent to the Italian standard scenarios (IT-STSs--specific category), according to the current regulation ([34, 35, 37, 38]). Such arrangements are summarized in Table 2.  
Figure 4: Emergency aerial photogrammetry activity: team pictures. Figure 5: Emergency aerial photogrammetry activity: in situ coordination base.