All field trials as PDF
Rickard Svedjesten, Swedish Police Mountain Rescue Service
Participants: ResQU personnel and Swedish Police Mountain Rescue Service.
Location: Oviksfjällen outside Åre in Sweden.
Date: May 2009
Field trial system
The system used at the field trials was made up of two separate parts, one Base Unit and one Search Units.
When the rescue team arrives at the deposit area they activate the Base Unit. From this instant the Base Unit is fully automatic and requires no operator. The Base Unit automatically first identifies all cell phones in the vicinity. It then forces all cellular phones within the search area to transmit a beacon signal. The Base Unit then communicates a list of all cellular phones in the search area to all Search Units.
Hepkie Search Unit prototype
Hepkie Search Unit prototype
The operator of a Search Unit can now search for all phones present, but can also choose to search for one or several specific phones. This is in order for the search party to be able to better coordinate the search. The identities of phones that are known to belong to rescue crew or are identified as not belonging to a victim can easily be excluded from the search.
Hiding phone for field trial
Precision and depth tests
We buried a mobile phone at a depth of 1.8 m and 0.5 m respectively and were able to locate it with an error of less than 30 cm.
Range tests
We also performed range tests for a helicopter based search indicating that the detection range of the Search Units is exceeding 10 km. A mobile phone was placed on another site 7 km away from the slope where the snow tests were made. Without any difficulty we were able to determine the direction to it from where we were standing.
Long distance field trial in Åre
Field trials started
Successful helicopter test