Articles | Volume 4, issue 2
Earth Surf. Dynam., 4, 359–389, 2016

Special issue: Frontiers in geomorphometry

Earth Surf. Dynam., 4, 359–389, 2016

Review article 19 May 2016

Review article | 19 May 2016

Image-based surface reconstruction in geomorphometry – merits, limits and developments

Anette Eltner1, Andreas Kaiser2, Carlos Castillo3, Gilles Rock4, Fabian Neugirg5, and Antonio Abellán6 Anette Eltner et al.
  • 1Institute of Photogrammetry and Remote Sensing, Technische Universität Dresden, Dresden, Germany
  • 2Soil and Water Conservation Unit, Technical University Freiberg, Freiberg, Germany
  • 3Dept. of Rural Engineering, University of Córdoba, Córdoba, Spain
  • 4Dept. of Environmental Remote Sensing and Geomatics, University of Trier, Trier, Germany
  • 5Dept. of Physical Geography, Catholic University Eichstätt-Ingolstadt, Eichstätt, Germany
  • 6Risk Analysis Group, Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland

Abstract. Photogrammetry and geosciences have been closely linked since the late 19th century due to the acquisition of high-quality 3-D data sets of the environment, but it has so far been restricted to a limited range of remote sensing specialists because of the considerable cost of metric systems for the acquisition and treatment of airborne imagery. Today, a wide range of commercial and open-source software tools enable the generation of 3-D and 4-D models of complex geomorphological features by geoscientists and other non-experts users. In addition, very recent rapid developments in unmanned aerial vehicle (UAV) technology allow for the flexible generation of high-quality aerial surveying and ortho-photography at a relatively low cost.

The increasing computing capabilities during the last decade, together with the development of high-performance digital sensors and the important software innovations developed by computer-based vision and visual perception research fields, have extended the rigorous processing of stereoscopic image data to a 3-D point cloud generation from a series of non-calibrated images. Structure-from-motion (SfM) workflows are based upon algorithms for efficient and automatic orientation of large image sets without further data acquisition information, examples including robust feature detectors like the scale-invariant feature transform for 2-D imagery. Nevertheless, the importance of carrying out well-established fieldwork strategies, using proper camera settings, ground control points and ground truth for understanding the different sources of errors, still needs to be adapted in the common scientific practice.

This review intends not only to summarise the current state of the art on using SfM workflows in geomorphometry but also to give an overview of terms and fields of application. Furthermore, this article aims to quantify already achieved accuracies and used scales, using different strategies in order to evaluate possible stagnations of current developments and to identify key future challenges. It is our belief that some lessons learned from former articles, scientific reports and book chapters concerning the identification of common errors or "bad practices" and some other valuable information may help in guiding the future use of SfM photogrammetry in geosciences.

Short summary
Three-dimensional reconstruction of earth surfaces from overlapping images is a promising tool for geoscientists. The method is very flexible, cost-efficient and easy to use, leading to a high variability in applications at different scales. Performance evaluation reveals that good accuracies are achievable but depend on the requirements of the individual case study. Future applications and developments (i.e. big data) will consolidate this essential tool for digital surface mapping.