UAS multi-camera rig for post-earthquake damage 3D geovisualization of Vrisa village

Abstract

Last years the role of Unmanned Aerial Systems is increasing in a wide variety of scientific aspects that need fast and reliable geodata. Nowadays, the effectiveness of the quality and the resolution that the UAS provide in spatial data acquisition are fulfilling scientific standards. Thus, UAS have a prominent role in post-earthquake damage assessment as they are capable of collecting high in resolution data for mapping spatiotemporal phenomena. The implementation of very detailed 3D Geovisualization requires oblique photos of the building faces. Thus, the UAS's data acquisition of nadir photos solely, is limited as it lacks crucial information for buildings facades. In this work, a UAS multi-camera rig installation is presented for the collection and simultaneous acquisition of nadir and in three different directions oblique photos. The acquired data were used for the creation of post-earthquake building facade 3D geovisualisation of Vrisa village in Lesvos island after the Mw6.3 earthquake on June 12, 2017 at two different spatial scales. The results showed that the use of a multi-camera rig attached to UAS can produce 3D visualizations capable of depicting in detail the diversity and the small size of cracks in roofs or facades of the post-earthquake buildings. Thus, the produced geovisualizations are a valuable tool for measurements of area and volume of house debris. Moreover, the results proved that the installation of a multi-camera rig in a UAS for data acquisition and the creation of accurate 3D visualizations using these data could be a valuable and useful tool for post-earthquake damage assessment.