Digital Surface Model of Mt. Etna, Italy, derived from 2015 Pleiades Satellite Imagery

A high-resolution, high vertical accuracy Digital Surface Model (DSM) of Mt. Etna was derived from Pleiades satellite data using the National Aeronautics and Space Administration (NASA) Ames Stereo Pipeline (ASP) tool set (https://ti.arc.nasa.gov/tech/asr/groups/intelligent-robotics/ngt/stereo/). The NASA Ames Stereo Pipeline (ASP) is a suite of free and open source automated geodesy and stereogrammetry tools designed for processing stereo imagery captured from satellites (around Earth and other planets), robotic rovers, aerial cameras, and historical imagery, with and without accurate camera pose information. The methodology used by the ASP software is similar with structure-from-motion (SfM) methodology using stereo triangulation combining spacecraft ephemeris/attitude information, sensor model, and disparity map information obtained by feature matching procedures. The model covers an area of about 400 km2 with a spatial resolution of 2 m and centers on the summit portion of the volcano. The model was validated by using a set of reference ground control points (GCP) obtaining a vertical root mean square error (RMSE) of 0.78 m. The horizontal accuracy is 1 cell (2 m) and the vertical resolution is centimeters. The described procedure provides an avenue to obtain DSMs at high spatial resolution and elevation accuracy in a relatively short processing time making the procedure itself suitable to reproduce topographies often indispensable during the emergency management case of volcanic eruptions.