Measuring 3D coastal change with a digital camera

Abstract

We explore the use of digital photography for reconstructing topographic data of coastal regions using ‘structure from motion’ (SfM) algorithms. 3D models are constructed from photographs taken from different positions in a workflow that offers significant simplifications in terms of data acquisition and automated processing, over traditional photogrammetry. Two different SfM implementations (one based on a local PC and the other on a web-based service) are demonstrated for quantifying surface change over different spatial scales - a subaerial beach, a cliff face and scour holes around vegetation tussocks. The results indicate that SfM is a promising tool for morphological measurement, capable of cheaply producing data that can be of a comparable accuracy to other commonly used techniques.