INTEGRATED SFM TECHNIQUES USING DATA SET FROM GOOGLE EARTH 3D MODEL AND FROM STREET LEVEL

Structure from motion (SfM) represents a widespread photogrammetric method that uses the photogrammetric rules to carry out a 3Dmodel from a photo data set collection. Some complex ancient buildings, such as Cathedrals, or Theatres, or Castles, etc. need toimplement the data set (realized from street level) with the UAV one in order to have the 3D roof reconstruction. Nevertheless, theuse of UAV is strong limited from the government rules.In these last years, Google Earth (GE) has been enriched with the 3D models of the earth sites. For this reason, it seemed convenientto start to test the potentiality offered by GE in order to extract from it a data set that replace the UAV function, to close the aerialbuilding data set, using screen images of high resolution 3D models. Users can take unlimited “aerial photos” of a scene while flyingaround in GE at any viewing angle and altitude. The challenge is to verify the metric reliability of the SfM model carried out with anintegrated data set (the one from street level and the one from GE) aimed at replace the UAV use in urban contest. This model iscalled integrated GE SfM model (i-GESfM). In this paper will be present a case study: the Cathedral of Palermo.