Methodology in the use of UAV ( Unmanned Aerial Vehicles ) by Assetto del Territorio sector of Liguria Region.
Authors: Schenone Davide , Daniele Bottero , Strippoli Mariano 
Published: March 2020

&lt;p&gt;Title: Methodology in the use of UAV ( Unmanned Aerial Vehicles ) by Assetto del Territorio sector of Liguria Region.&lt;/p&gt;&lt;p&gt;Authors:&amp;#160;Davide&amp;#160;Schenone&amp;#160;, Daniele Bottero, Mariano Strippoli.&lt;/p&gt;&lt;p&gt;Liguria&amp;#160;Region&amp;#160;has recently equipped itself with a UAV (&amp;#160;Unmanned&amp;#160;Aerial&amp;#160;Vehicles&amp;#160;) system, consisting of a DJI&amp;#160;Phantom&amp;#160; 4 pro, the choice fell on this type of equipment as it guarantees a good quality for photographic shooting combined with an ease of use deriving from the fact of being designed for a consumer market, in fact this model mounts advanced anti-collision systems on board which make it safe to use even in closed places or near tall trees, the latter being a frequent situation in the use carried out by regional technicians.&lt;/p&gt;&lt;p&gt;In addition, maintenance is facilitated as spare parts (essentially batteries and propellers) can be found easily on the main online sites, given the widespread use of the model.&lt;/p&gt;&lt;p&gt;The use of the drone by the Assetto del Territorio consists mainly of two sectors, terrestrial photogrammetry and aerial photogrammetry.&lt;/p&gt;&lt;p&gt;The intervention scenarios are essentially of two types, survey of existing situations, for example, delimitation of landslides that may or may not have evolved, or the survey of post-disaster situations, both hydraulic and&amp;#160;gravitational&amp;#160;, it is also possible monitor the evolution of phenomena through&amp;#160;multitemporal&amp;#160;recovery&amp;#160;.&lt;/p&gt;&lt;p&gt;The terrestrial photogrammetry it is so far little used by the Region and regarding&amp;#160; the capture of perspective images of buildings, cliffs useful for the relief&amp;#160;geomechanical&amp;#160;to evaluate rock mass, paleoseismic trenches (for upthrow of fault) etc.&lt;/p&gt;&lt;p&gt;As for&amp;#160;the method of data acquisition (images), and the preparation of the flight plan, the DJI GS PRO software for iOS operating systems is used, this software allows to&amp;#160;automatically&amp;#160;set&amp;#160;the flight parameters, simply by drawing on a map the polygon of the area to be surveyed and the flight height, it is also possible to adapt the orientation of the strips to the polygon of the survey.&lt;/p&gt;&lt;p&gt;However, this software does not require the use of a&amp;#160;DTM&amp;#160;, which takes into account the elevation of the terrain, so in case of relief of slope portions inclined taken the take off from the highest point since the calculation of the frames overlap is carried out assuming&amp;#160;that&amp;#160;the ground&amp;#160;is&amp;#160;flat&amp;#160;, if it were not so taking off for example in the lower part it could happen that for purely geometric issues in the top part the overlapping of the frames&amp;#160;is&amp;#160;insufficient to arrive at a correct processing via software.&lt;/p&gt;&lt;p&gt;As regards the processing of immage&amp;#160;in order to produce a cloud, depending on the cases of the DTM points and l '&amp;#160;orthophotos&amp;#160;the software is normally used&amp;#160;Metashape&amp;#160;by&amp;#160;Agisoft&amp;#160;, the&amp;#160;workflow&amp;#160;typically used is this:&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;ul&gt;Adding photos&lt;/ul&gt;&lt;ul&gt;Alignment of photos - maximum resolution&lt;/ul&gt;&lt;ul&gt;Point&amp;#160;cloud&amp;#160;creation&amp;#160;- medium resolution&lt;/ul&gt;&lt;ul&gt;DEM creation&lt;/ul&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;