Abstract: In the past few years, a new low-cost, efficient photogrammetry mapping method called structure from motion (SfM) has been applied to the high spatial resolution three-dimensional topographic data collection. As the latest and a very significant advance in digital surveying, SfM has only been applied to the geosciences to produce orthophoto mosaics, three-dimensional (3D) point clouds, and digital elevation model (DEM) since 2011. SfM derived products have been produced to detect changes and hence to infer dynamic processes in glacial, fluvial, coastal, hillslope, dryland, volcanic, and shallow underwater environments. In this paper, historical imagery archives of 2005-2009 acquired from a UAV have been processed using SfM to create hyper spatial resolution orthophoto mosaics and DEM. A statistical analysis indicates that the results have an overall accuracy of about 0.13-0.23m. Precise and detailed data derived from archive UAV imagery with SfM are essential descript fluvial geomorphology and also helpful to detect, monitor and predict fluvial geomorphic process.
Keywords: fluvial remote sensing; UAV; SfM; orthophoto mosaics; DEM