Event detection

The detection of avalanches, debris flows or rockfalls is carried out by a measuring system which is placed in the area of the fall path in such a way that the event can be detected as clearly as possible with a sufficiently long warning time.

To identify an event, the signals from various sensors are continuously recorded and evaluated. The use of several different sensors increases redundancy and thus the availability and reliability of a system. It also improves the detection quality, i.e. the differentiation of dangerous natural hazard events from interference sources or events that are too small.

Sensor	Measured variable	Application for
Sensor	Measured variable	Avalanches	Debris flow	Rockfall
Doppler radar	Speed	x	x	x
Geophone	Vibration	x	x	x
Detection cable	Tractive force	x
Pressure plate	Pressure	x	x
Level probe (radar / ultrasound)	Discharge height		x
Debris flow combi sensor	Pressure / Vibration / Noise		x

Table 1: Typical sensor systems for event detection by natural hazard alarm systems

The conditions for triggering an alarm can be freely configured from any combination of various signal parameters of the different sensors and continuously adapted and optimized based on empirical values from events.

Our systems are optimized for minimum energy consumption as well as simple and robust signal evaluation. This enables fully autonomous operation as well as independence from external infrastructure.

All these factors lead to extremely high reliability and availability - a mandatory requirement in order to effectively achieve the reduction of residual risk aimed for with an alarm system and thus ensure the safety of plant users.