Uav Photogrammetry With Oblique Images: First Analysis on Data Acquisition and Processing

Abstract

Commission I, WG I/VbKEY WORDS: UAV, Oblique Imagery, photogrammetry, SfM, point clouds, cultural heritage, architectural 3D models ABSTRACT:In recent years, many studies revealed the advantages of using airborne oblique images for obtaining improved 3D city models (e.g. including façades and building footprints). Expensive airborne cameras, installed on traditional aerial platforms, usually acquired the data. The purpose of this paper is to evaluate the possibility of acquire and use oblique images for the 3D reconstruction of a historical building, obtained by UAV (Unmanned Aerial Vehicle) and traditional COTS (Commercial Off-the-Shelf) digital cameras (more compact and lighter than generally used devices), for the realization of high-level-of-detail architectural survey. The critical issues of the acquisitions from a common UAV (flight planning strategies, ground control points, check points distribution and measurement, etc.) are described. Another important considered aspect was the evaluation of the possibility to use such systems as low cost methods for obtaining complete information from an aerial point of view in case of emergency problems or, as in the present paper, in the cultural heritage application field. The data processing was realized using SfM-based approach for point cloud generation: different dense image-matching algorithms implemented in some commercial and open source software were tested. The achieved results are analysed and the discrepancies from some reference LiDAR data are computed for a final evaluation.

UAV photogrammetry for archaeological site survey. 3D models at the Hierapolis in Phrygia (Turkey)

“…Due to the scale of the photogrammetric products that are adaptable to the flight altitude, and the downstream of the experiences gained, we can say that the drone surveys are particularly effective for the following purposes that are commonly carried out in archaeological sites. Indeed, starting from 2015 and following the latest research addresses in terms of flight plans, camera configuration and dense image matching algorithms in photogrammetric blocks acquisition and processing, the contribution of oblique acquisition in the 3D models definition is crucial and deepened in more recent research realized by our research group (Aicardi et al, 2016;Chiabrando, Lingua, Maschio, & Teppati Losè, 2017;Chiabrando, Spanò, Sammartano, & Teppati Losè, 2017;Piras, Di Pietra, & Visintini, 2017) …”

Hybrid 3D Models: When Geomatics Innovations Meet Extensive Built Heritage Complexes

“…To test other image-based sensors, in addition to the UAV data, different terrestrial acquisitions were carried out to document the analysed areas. The followed approach is the one that is well consolidated in the community that require large image overlapping using parallel and convergent images [47], when considering all the above internal/external light conditions.…”

Hybrid 3D Models: When Geomatics Innovations Meet Extensive Built Heritage Complexes

“…In order to test other image-based sensors, in addition to the UAV data, different terrestrial acquisitions were carried out to document the analyzed areas. The followed approach is the one well consolidated in the community that require large image overlapping using parallel and convergent images [51], pandering above all the internal/external light conditions.…”