The Virtual Outcrop Geology Group is a collaboration between Uni Research CIPR, Bergen, Norway, and the University of Aberdeen, UK. The group was established in 2004 and focuses on the study of geological outcrops to address reservoir related challenges, and specializes in the acquisition of outcrop data using novel collection techniques such as laser scanning (lab, terrestrial and helicopter-based), photogrammetry (across the scales: lab, ground, UAVs and boats) and focus on novel means of processing, visualising and extracting information to fully exploit the methods in research and industry. We also work on hyperspectral imaging to complement the geometric models with material mapping. These methods are becoming increasingly relevant to other disciplines, and the group has worked with projects in geoscience and energy research, mining, material recycling and cultural heritage.
The VOG Group has been at the leading edge of digital outcrop geology for over ten years, pioneering many of the developments in data acquisition, processing, and distribution. To facilitate the interpretation, visualisation and communication of 3D photorealistic models, the group develops the LIME software. The group consists of multidisciplinary experts in geology, geomatics and computer science. In September 2016, the VOG Group is convening the 2nd Virtual Geoscience Conference (VGC2016) in Bergen (virtualoutcrop.com/vgc2016).
1. 3D acquisition, analysis and visualisation
3D modelling of exposed rock outcrops (such as cliff sections, quarry and mine faces, and other topographic features) based on laser scanning (lidar) and photogrammetry has become an effective method for the capture of geometric data for understanding geological processes. In the petroleum industry, such models are used to extract measurements and aid interpretations, as well as for supporting field excursions (real and virtual) that can be in remote and difficult to access areas. The main advantages are high resolution and accuracy, and the combination with digital photographs to fuse 3D detail with rich image texture in natural outcrops. The models may be accessed on computers and in 3D environments for interpretation and collaborative work. The work of the VOG group has focussed on the exploitation of terrestrial lidar and photogrammetric data in geoscience. We address bottlenecks in data processing, visualisation and application usage that have previously been a barrier to adoption of these methods by end users. The choice of measurement technique is chosen according to the application needs and may be based on different lidar and photogrammetric equipment and platforms. We develop LIME, a viewing, interpretation and presentation software to allow project results to be distributed to and worked with by partners, as well as other in-house software for processing 3D model data.
2. Hyperspectral imaging
Hyperspectral imaging has been used for geological applications for many years and is based on the physical interaction of electromagnetic radiation (reflection properties of sunlight) with surface material. Many minerals in rocks show specific absorption features in the visible and infrared wavelengths, which can be used as a diagnostic tool to identify and map these mineral and chemical variations. With hyperspectral scanners, the reflected light is sampled with a high number (several hundred) of very narrow (~5nm) spectral bands, which results in a near-continuous spectral curve for each image pixel. Our expertise includes the scanning of near-vertical cliff sections (such as geological outcrops and mine faces) and spectral analysis of drill cores and samples. We also have developed new ways of communicating end results, by combining hyperspectral images with 3D lidar and photogrammetric data. Hyperspectral methods offer added value by allowing non-contact and high resolution identification and description of materials of interest.
3. Data integration and analysis
As well as 3D model generation, usage of extracted data is important to achieve application results. Early work integrated outcrop models and interpretations into reservoir modelling workflows. Incorporating field observations into 3D environments, together with a narrative and background information allows the use of photorealistic datasets as the basis for virtual excursions. Our data integration and analysis activities are currently concentrated on the SAFARI database project. The main goal is to develop a fully searchable repository of geological outcrop data from clastic sedimentary systems for reservoir modelling and exploration, and to improve our understanding of sequence stratigraphy. Many different data types are integrated in a uniform way, together with a knowledge base, and geological outcrops from around the world are implemented. A novel 3D viewer allows large photorealistic models to be served over the Internet.