Image-based modeling of built environment from an unmanned aerial system

• Automatic image-based modeling for as-built complex constructions
• Application of unmanned aerial system to as-built metric models
• Low-cost three-dimensional as-built metric models of an electrical substation
• Accuracy assessment of the UAS dense surface reconstruction against laser scanner
• Non-invasive three-dimensional reconstruction of complex scenarios

In recent years, the modeling from images, called image-based modeling, is emerging as a powerful alternative for the as-built three-dimensional (3D) reconstruction of complex scenarios compared with the use of laser scanner technology or classical topographic methods. Image-based modeling is a non-invasive and low-cost technology that allows 3D reconstruction of objects and scenarios by using only images. However, although several tools currently exist for converting from two-dimensional (2D) to 3D, the specific requirements of quality and completeness for these types of scenarios are difficult to determine.In this paper, a methodology for automatically reconstructing 3D complex scenarios, particularly electrical substations, using images acquired from an unmanned aerial system is analyzed and proposed. This methodology has been incorporated by the Iberdrola Company as an optimal technique for obtaining low-cost 3D as-built metric models of electrical substations. The results obtained show that this camera-based low-cost system is a competitive alternative to laser scanning systems for modeling as-built complex constructions and can become an essential tool for facility planning and management tasks.