The most widespread application of drones is acquiring\u00a0images <\/b>or videos<\/b> from unusual perspectives, i.e., from the sky. Depending on the application field, these sensors can serve different scopes. In the Cultural Heritage field, it is possible to evaluate the conservation state of artistic buildings and architectures by developing 3D models. Moreover, if the drones are equipped with thermal sensors<\/b>, the surveyor knows if problems are linked to the humidity and infiltrations in the roofs<\/b>.\u00a0<\/p>\r\n
Another example regards the environmental field: drones can help to control the pollution<\/b>, radioactivity,<\/b> and contamination<\/b> of risk areas. Vulcanic areas<\/b>, landslides<\/b>, avalanches<\/b>, floods<\/b>, fires<\/b>, mining explorations<\/b>, and hydrogeological instability <\/b>can be monitored by UAVs instead of put-in-danger operators and workers. In the event of natural disasters, <\/b>the rescuers clearly understand the situation and can organize the aid. In agriculture<\/b>, drones are used to create the NDVI <\/b>(Normalised Difference Vegetation Index) maps that help farmers understand if their plants are suffering or if they are sick<\/b>.<\/p>\r\n
Go below and see our work with drones:<\/p>\r\n
Duomo di Milano<\/a><\/p>\r\n Borgo Croppomarcio<\/a><\/p>\r\n Sinergia Project<\/a><\/p>\r\n Montecalvoli Pisa<\/a><\/p>\r\n Santa Barbara Bell Tower<\/a><\/p>\r\n\r\n DUOMO DI MILANO<\/strong><\/a><\/p>\r\n\r\n\r\n\r\n In 2009<\/strong> there was the necessity to create the 3D model of the Main Spire <\/strong>of Milan Cathedral for maintenance<\/strong> purposes. Since there was some problems with other technologies <\/strong>(laser-scanner), it was decided to plan a photogrammetric acquisition <\/strong>using a remote controlled helicopter<\/strong> with a camera<\/strong>.<\/p>\r\n\r\n\r\n\r\n The outcome<\/strong> of the survey is a set of images <\/strong>that needed to be orientated manually <\/strong>using a photogrammetric software. The orientation of the images consists in finding homologous points <\/strong>(more than 3, but it is suggested at least 20) on the images<\/strong>.<\/p>\r\n\r\n\r\n\r\n At the end of the photogrammetric process, it was necessary to draw on the images a wireframe model<\/strong>, and then transform it into a 3D model<\/strong>, building the surfaces and volumes between the wires.<\/p>\r\n\r\n\r\n\r\n Difficulties:<\/p>\r\n\r\n\r\n\r\n \u2022Piloting an helicopter between the spires<\/strong>;<\/p>\r\n\r\n\r\n\r\n \u2022Respecting a geometry of acquisition <\/strong>suitable for photogrammetric purposes;<\/p>\r\n\r\n\r\n\r\n \u2022Orienting<\/strong> manually a large number of photos<\/strong>.<\/p>\r\n\r\n\r\n\r\n The work evolved <\/strong>in the years and today, 2020, the survey of the Cathedral is complete. The last part surveyed was the main rooftop<\/a><\/strong>. In normal condition it was almost impossible to obtain a precise survey with no interference, because the main rooftop is crowded of tourist 7\/week, 365\/year<\/strong>.<\/p>\r\n\r\n\r\n\r\n In July 2020<\/strong>, during the lockdown, it was possible to fly a small drone and get a precise and high resolution survey of the roof<\/strong>.<\/p>\r\n\r\n\r\n\r\n The survey was performed using the DJI Spark <\/strong>drone.<\/p>\r\n\r\n\r\n\r\n