Avalanche transceiver

An avalanche transceiver ( avalanche transceiver ), also called avalanche beacon is an electronic device for avalanche rescue. With the avalanche transceiver can under certain circumstances persons who were buried by an avalanche, aim for and quickly locate to hide it possible without any time delay can. This is important because the chances of survival Spilled decreases drastically after 15 minutes.

Function

ARVA have two operating modes: transmit and search operation.

In the transmit mode, the device sends a radio signal at a frequency of 457 kHz, which is internationally standardized in ETS 300718 at short intervals. For ski touring and downhill variant the device in the transmission mode is worn on the body.

A security rule in the off-piste terrain means that you should move there only in the group and that the individual group members should keep a large distance from each other. This is to ensure that not all group members are caught by an avalanche. Group members who have escaped the avalanche, then put their beacons to receive ( search) and can locate the signal of the victims. Depending on the avalanche transceiver, location and burial depth, the range is 20-40 m.

Because the acoustic signal a beep when receiving, the Austrian avalanche transceivers manufacturer can protect the word " beep " as a company and brand names " beep GmbH " and refers to its units as a peep. Regardless of the manufacturer and brand name ARVA are often referred to as beepers or avalanche beacon.

An avalanche beacon belongs next to avalanche probe and shovel standard equipment for ski touring, free-riders and other winter sports enthusiasts away from the secured ski runs.

In addition to these active devices also support a passive reflector can be located under an avalanche. These passive reflectors are partially processed as standard in ski clothes.

Technical developments

The development of avalanche transceivers aims accident that people can be located more quickly and accurately. The first devices were working analogous to an antenna, they showed the distance to the victim of the loudness of the tone. Later devices with two antennas and a display have been put on the market, which indicated not only the distance, but also the direction ( along a line field ).

In 2003 came with the Pieps DSP the first digital avalanche transceivers with three antennas on the market. This generation of devices, which is now offered by all major manufacturers, is more accurate and faster. It also provides the ability to locate a plurality of buried simultaneously.

Expiration of a search

Crucial for a good and fast result is the trained dealing with the avalanche transceiver, which requires regular exercises. An efficient search procedure is also dependent on a systematic approach, so the search process is divided into different phases. The relevant nomenclature is not uniform, different classifications have already been used. The International Commission for Alpine Rescue ( ICAR ) recommends as of 2009 the procedure in four phases: searching for signal, coarse search, fine search and point search.

The signal search is for the systematic pacing of the avalanche cone (starting, for example, when last seen the victim under the snow ) until receipt of a first signal with the avalanche transceiver or another character from the victim ( sighting, sounds, ...). The clear procedure for signal search depends not only on the number of seekers by peculiarities of the avalanche transceiver, in particular of its range, from. The coarse search ranges from the point of the first signal reception ( which is usually marked ) to the immediate area of the victim. For the transceiver, this point is defined as that where the amplitude of the signal is decreased for the first time in all directions. In this phase digital and analog transceivers require different search strategies. Even with the fine search in the local area, where mostly working just above the snow surface, it can cause maximum design differences between various models LVS ( analog- or two-or three -antenna device ). The fine search ends after today ICAR nomenclature with the transition to the use of avalanche probe. When pinpointing earlier, the search was called with the avalanche transceiver at close range, now the search is taken by a probe to locate the victim under this term.

Be particularly challenging, " multiple burial " apply, so if multiple people are buried under the snow, because the signals can overlap especially in closely spaced victims. In this case, special methods such as the three - circle method or procedure with micro search strip are necessary. Some devices have their own functions for special search strategies in such cases.