Swiss engineering firm IMPULS AG was tasked with monitoring erosion and the risk of rockfalls along the Gotthard Pass roadway that connects northern and southern Switzerland through the Alps. With high and dramatically changing elevations, traditional surveying methods would be impossible in some places and very dangerous in others. On the other side, placing things like ground control points (GCPs) would be equally difficult.
The company called in surveying specialist Pixmap which uses a WingtraOne fixed-wing drone. Within one day, the team was able to cover 48 hectares along the Gotthard Strasse mountain road pass. In the process, they captured 460 images that enabled the company to create a 3D model accurate to 6cm.
One of the key benefits of the WingtraOne in this instance was its terrain-following feature. It enables the craft to adjust its height so that it remains at a constant altitude above ground level and helps to provide greater accuracy. WingtraOne was also flying at a fixed horizontal distance from the side of the mountain to further reduce the risk of crashing. Plus, Switzerland has a law that prohibits drone flights above 150m (492ft) in controlled airspace, so it also helped to prevent any accidentally illegal operations!