Snow depth profile scanner Gotthard
The Gotthard region frequently gets large quantities of new snow on both the north and south sides of the mountain ridge. This can be challenging for rail and road operations, such as SBB (Swiss Federal Railways). The train engine can clear considerable amounts of new snow from the tracks during the ride. Above a certain snow height, however, it is necessary to use the rotary snow plough, which is time-consuming. SBB therefore needs regular snow depth information on either side of the Gotthard in order to plan snow clearing and stick to the timetable. An automatic monitoring system should measure the snow profile on the tracks at short intervals and inform the responsible people immediately if a critical amount of snow is exceeded. A spot measurement is not good enough, as snow drift can lead to complex snow distributions on the tracks.
Before winter 2018/19, we installed two automatic snow profile measurement systems for SBB in Göschenen (north side) and Airolo (south side of Gotthard pass). A laser scanner mounted on the track side continuously scans the track bed and transmits the data to the Geopraevent online data portal. At this portal, proprietary evaluation algorithms analyse the data and convert it into a profile view. Interferences, such as passing trains or snowfall, are automatically filtered.
The superposition of the measured snow profile and the clearance profile of the train is used to determine if the rotary snow plough is needed. If the overlap exceeds a critical value, automatic notifications via SMS and email to the responsible persons is triggered. The laser scanners permanently generate snow depth profiles – independent of the prevailing weather, both day and night. Every 15 minutes, the profiles are uploaded to the online data portal where they are available to authorised users via PC, tablet or smartphone along with additional snow as well as meteorological data.
In addition, both stations are equipped with a remote-controlled camera including an infrared spotlight. The camera with pan-tilt-zoom function provides live views of the situation at any time via the data portal and automatically takes a picture with each profile scan. This allows remote visual inspection of the measurement at any time.