To verify the measured accuracy of the snow depth on the roof by SfM-based photogrammetry using aerial images, the authors performed aerial photography by UAV and measurement of the roof snow depth for the gymnasium of Hokkaido University of Science. Phantom 4, Phantom 3, and Mavic Pro were used for aerial photography. As a result, it was found that the RMSE of the roof snow depth was 30 to 40 mm. In addition, it was found that it is necessary to secure the number of images that satisfy the conditions of 90% overlap ratio and 60% side overlap ratio.
