Inspecting the outcrop structures such as fractures, weathering morphologies is essential to understand the environment of corresponding field. Traditionally the inspection has been conducted by visual observation manually. However, manual inspection becomes difficult when there are the parts of observed geological object which are hard to be partially or totally accessed. On the other hand, unmanned aerial vehicles (UAV) technology has been developed in recent years. Using UAV, some useful geological information with respect to outcrops may be obtained safely. Additionally, combining UAV with some image processing techniques, digital 3D model of outcrop (Digital Outcrop Models; DOMs) might be obtained. Whereas, virtual reality (VR) technique has been developed recently. Using VR, users may get immersive access to the data and human motion by themselves. In this situation, in this study the authors develop an inspection system based on UAV and VR techniques with 3D depth camera in order to obtain the information of geological features on outcrops.
On outcrops there are various characteristic structures such as fracture, weathering morphology, rock fall marks and fault. Inspecting such structures is essential to understand the environment of corresponding field and for a wide range of geoscientific research, for example prevention of rock fall hazard, etc. (Arbanas et al., 2012) Traditionally the inspection has been conducted by visual observation manually. However, manual inspection becomes difficult when there are the parts of observed geological object which are hard to be partially or totally accessed.
With resent advances in aerial data acquisition technologies from unmanned aerial vehicles (UAV), it is possible to capture some high-resolution image of rock surfaces and analyze geological structures safely. Additionally, combining UAVs and image processing technologies, we may construct 3D models of the outcrops digitally. These 3D models are called as Digital Outcrops Models (DOMs). Using DOMs obtained from photogrammetry, it would be possible to analyze structural features and properties digitally where photogrammetry is a technique that captures 3D information of features from two or more photographs of the same object obtained from different angles. Recently, low-cost depth camera for consumers that may archive 3D point clouds data rapidly has been developed. Accordingly, we have been able to cite various succeeding results about combination of UAVs and digital photogrammetry (Lin et al., 2010; Danzi et al., 2012; Bemis et al., 2014; Baski et al., 2014; Tziavou et al., 2018). Although their success, there is a difficulty to analyze geological features using them in situ. That is, traditional methods could not manipulate obtained DOMs intuitively and in real-time.