Current Applications of Structure from Motion in the Geosciences

Abstract

The geosciences are employing structure from motion (SfM) to produce orthophotograph mosaics, three-dimensional (3D) point clouds, and digital elevation models (DEMs) of difference. In overview, many geoscience applications of SfM to date are essentially proof-of-concept studies, but those with robust analyses of error and uncertainty are invaluable to others to ensure scientific rigour and ultimately appreciation of the possibilities offered by an SfM workflow. SfM-derived orthophotograph mosaics have been used for mapping and to calculate planform geometry and surface grain-size distribution. SfM 3D point clouds have (i) aided definition of complex geometry, such as boulders and cliff or gully undercuts; (ii) been used to determine tree biomass, (iii) provided for novel structural analyses of hard rock geology and (iv) enabled automated compositional analyses of soft sediments. DEMs from SfM processing have been created across a range of spatial scales and at a range of spatial resolutions and compared in 3D quality to other digital survey methods. DEMs have been differenced to detect topographic changes and hence to infer dynamic processes in glacial, fluvial, coastal, hillslope, dryland, volcanic, and shallow underwater environments. Whilst there are now commercial enterprises offering SfM services, workflows have yet to be fully embraced within industrial applications.