A system for locating mobile objects in distress comprises emergency radio stations provided on the mobile objects and energized when these mobile objects are in distress, at least one low orbiting earth satellite for retransmission of the signals from the emergency stations, at least one control station...http://www.google.es/patents/US4240079?utm_source=gb-gplus-sharePatente US4240079 - System for locating mobile objects in distress
