Haiti Earthquake. Photo by by United Nations Development Programme /Flickr
Scenario: A major earthquake affecting an urban area. An estimated 70% of all houses are demolished and thousands of people missing.
10 portable HEPKIE systems (10 Base Units and 50 hand-held Search Units) are on the spot after 12 h.
The SAR team leader has divided the worst-hit area into search grid before arrival. The grid cell size is 150 x 150 meters.
The HEPKIE systems are distributed one in each search grid cell, so that there is always about 500 m between two HEPKIE systems. This serves several purposes:
- Since each search group need to work at their own pace, the HEPKIE systems cannot be synchronized which would have been required to activate all phones in the whole affected area.
- Together with all the remaining base stations the HEPKIE systems would occupy all the available radio bandwidth. By spreading out the systems over the search area radio frequency spectrum can be reused.
- One HEPKIE system can only handle a small amount of phones compared to the possible number of victims in this scenario.
Earthquake in Indonesia, Photo by Andri Suprihadi /Flickr
The search should be organized so that the system does not interfere with normal mobile traffic more than necessary and always in a limited area. This is only a problem if the mobile phone system is still operational. In major disasters it is not uncommon that the mobile phone network also is destroyed in which case interference is no longer a problem.
All phones connected to the HEPKIE Base Unit will receive a text message informing them about the ongoing SAR activities and that the person not in need of assistance need to restart their phone in order to regain normal functionality. A large number of phones will then remove themselves from the list of potential victims.
MINUSTAH peacekeepers continue to work to find survivors. Photo by United Nations Development Programme /Flickr
The search begins with five hand-held HEPKIE Search Units. One of the search units can be a assigned the task to identify phones that are not buried to eliminate them from the search. The four other search units will be used to search for the buried phones in the area.
The operator of the HEPKIE Search Unit locates where the signal comes from, marks the location and continues with the next phone. It takes a maximum of 10 minutes for the rescue team to ensure the origin of the signal from a phone buried in rubble, from a distance of about 150 m. This means that a rescue team in this example can find 24 people per hour and the whole operation 240 phones per hour.
By gradually working through the search grid an area of 2.25 km2 can be searched in 10 h and 2400 phones, and hopefully as many victims, can be found.
