Using technology to protect mountain populations
© 2012 EPFL
Mountain villages concerned about the stability of hillsides and rock faces are benefiting from advanced cartographic technology. In collaboration with cantonal officials, a data-gathering platform made up of navigational and imaging devices is sent aloft in a helicopter. GPS, accelerometers and gyroscopes determine the position and orientation of the platform, which in turn defines the topographical position of the pixels in the digital images and the impact points from laser sweeps.
This "direct geo-referencing" enables mapping in the absence of known reference points, as opposed to classic aerial mapping which requires a ground-based reference. The millions of data points from the laser and digital images allow engineers to model the zone in three dimensions, revealing characteristics that are important for risk analysis.
Recent developments focus on an in-flight assessment of data quality. If data for part of the zone do not meet density and precision criteria, the operator is immediately informed. The pilot can go back to the critical zone, ideally from another angle. This way, the team is sure of gathering adequate data before landing.