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A Digital Outcrop Model (DOM), also called a virtual outcrop model, is a digital 3D representation of the outcrop surface, mostly in a form of textured polygon mesh. DOMs allow for interpretation and reproducible measurement〔J.A. Bellian, C. Kerans and D.C. Jennette, 2005. Digital Outcrop Models: Applications of Terrestrial Scanning Lidar Technology in Stratigraphic Modeling, Journal of Sedimentary Research, vol. 75, issue 2, pp. 166-176〕 of different geological features, e.g. orientation of geological surfaces, width and thickness of layers. The quantity of identifiable and measurable geological features highly depends on the outcrop model resolution and accuracy.〔S. Buckley, J. Howell, H. Enge, T. Kurz, 2008. Terrestrial laser scanning in geology: data acquisition, processing and accuracy considerations. Journal of the Geological Society, 165(3),pp. 625-638〕 Using remote sensing techniques enables these 3D models to cover areas with difficult accessibility, e.g. several meter high cliff walls. The fact that geological interpretation can be performed on the screen, also in inaccessible areas where using conventional fieldwork methods may be unsafe, and the large quantity of data that can be collected in relatively short time are the key advantages of using DOMs.〔S. Buckley, H. Enge, C. Carlsson and J. Howell, 2010. Terrestrial Laser Scanning for use in Virtual Outcrop Geology. The Photogrammetric Record, 25(131), pp. 225-239 http://dx.doi.org/10.1111/j.1477-9730.2010.00585.x〕 Georeferencing digital outcrop models allows for integration with other spatial data, e.g. results of digital geologic mapping or GIS. Alternatively to the photorealistic textured models 3D digital outcrop models may be represented by a point cloud coloured with the spectral (RGB) data from the corresponding images. Such surface model representation accurately describes the topography of the outcrop but due to its discrete nature is often difficult to interpret (see Figure 1.). Texturing digital polygonal outcrop models with images enhances the models with high resolution continuous data and therefore facilitates geological interpretation.〔 ==Creation techniques== Creation of textured DOMs can be divided into three main steps: * creation of the outcrop surface model, * pre-processing and registration of images covering the outcrop, * texture mapping. In order to achieve the required model resolution and accuracy data are mostly collected from the ground〔 (terrestrial) or from a helicopter platform (mobile mapping).〔S. Buckley, J. Vallet, A. Braathen, W. Wheeler, 2008. Oblique helicopter-based laser scanning for digital terrain modelling and visualisation of geological outcrops. IAPRS 37(B4), pp.493-498, (pdf ).〕 Airborne and satellite data may also be integrated but mostly as complementary datasets for the outcrop areas where close-range data are missing.〔S. Buckley, E. Schwarz, V. Terlaky, J. Howell, R.W. Arnott, 2010. Combining aerial photogrammetry and terrestrial lidar for reservoir analog modeling. Photogrammetric Engineering & Remote Sensing, 76(8), pp. 953-963.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Digital outcrop models」の詳細全文を読む スポンサード リンク
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