Historical 3D Topographic Reconstruction of the Iwaki Volcano using Structure from Motion from Uncalibrated Aerial Photographs

Christopher Gomez (1, 2)

1 Department of Geography
2 Natural Hazards Research Centre

The acquisition of topographic data is crucial for earth sciences, especially for the monitoring of topographiy that may change drastically in a short-time such as volcanoes. Precise topographic data are usually acquired using Lidar technologies, both airborne and terrestrial, but this method tends to be very costly both financially and in term of time for data processing. The present article present therefore an alternative technique, which has been only described once in a earth-sciences article: Structure from Motion (SfM) combined with Multiple View Stereophotogrammetry (MVS). SfM-MVS is a technique developed in computer vision that allows the calculation at the same time of both the position of the camera and the reconstruction of the 3D of a scene, and then recreate a 3D mesh of the topography. The present article is testing the technique at the Iwaki volcano in Northern Honshu in Japan, using a series of historical aerial photographs taken in 1965, 1985 and 1994. This has allowed the reconstruction of the topography and the drawing of orthophotographs, but comparison with data provided by topographic data have shown that the accuracy of the topographic results tends to reduce at the external limits of the volcanoes, most certainly because of the lack of images to accurately calculate the elevation. In order to confirm the validity of the technique and to show that the lack of accuracy is linked to the character of the data, a laboratory experiment using a decimeter scale sample was conducted. The results of this experiments showed excellent and accurate results with 3D points characterized by a correlation coefficient R2 or 0.9985 between the calculated and the measured data. This demonstrates the possibility of such technique, not only in earth sciences, but also archaeology, space exploration, etc.

Domaines: Environnement et Société; Sciences de la Terre

Christopher Gomez. Historical 3D Topographic Reconstruction of the Iwaki Volcano using Structure from Motion from Uncalibrated Aerial Photographs. 2012. ⟨hal-00765723⟩