Building a virtual outcrop, extracting geological information from it, and sharing the results in Google Earth via OpenPlot and Photoscan: An example from the Khaviz Anticline (Iran)

摘要

Photogrammetry is becoming a highly efficient alternative technique to laser-scanning for creating virtual outcrop models. It is easy to create a 3-dimensional digital model of an outcrop and extract geological information contained in it by using photos taken from different locations and integrating few free and/or cheap software. Subsequently, both the virtual outcrop and the geological data can be easily uploaded into Google Earth for sharing purposes. This is opening a door to the use of virtual outcrops in geology, for both research and teaching, which due to the costs and computers' skill requirements, was limited to a few. The aim of this paper is to present methodologies involved in the creation, analysis and sharing of low-cost easily-built virtual outcrops, which can be extensively used for the introduction to the 3D geology. An example from the Khaviz Anticline (Iran) is used to create a 3D digital model from a set of non-oriented images, using Agisoft Photoscan photogrammetry software. The obtained geopositioned model is then imported into OpenPlot, from which geological surfaces can be extracted. These data, together with the 3D model, can be later exported in Google Earth format.