3D point cloud (right) of the debris slide seen in previous image. This point cloud, used to determine the total volume of the debris, was created in PhotoModeler from about 90 individual photos of the slide. SmartMatch points can be seen dotting the actual site images on the left.
drive the excavator over these spots for as much of the route as possible to provide safety for the operator in case the machine broke through the ice.
Sakals used PhotoModeler to build a 3D model of the canyon and obstruction from the still photos collected with FLNRO’s UAS. He then used PhotoModeler to create an orthophoto, which is an aerial photograph that has been geometrically corrected so that every section of the photo looks as though it’s a birds eye view from directly above, without the distortion inherent with a photo from a single camera position. The orthophoto gave their machine operator an accurate map to plot his driving route to maximize time over the safer sections of ice. “The 3D model enabled us to understand the exact extent of the obstruction and helped to evaluate alternative removal methods,” Sakals said. “The model also helped predict the potential for further landslides and the risk these might pose to workers involved in clearing the obstruction.”
In another project, Sakals investigated the downstream effects of a recently constructed dam. Dams commonly trap larger debris such as tree trunks, which can create scour pools that become significant fish habitats and also affect the distribution of finer sediment in the stream. In this