Personal emergency location system

摘要

A personal emergency location system (PELS) employs a small battery-powered personal unit worn by a person who may be lost overboard. The personal unit has a GPS receiver and processor for determining the person's GPS location coordinates, and an RF transmitter for sending an RF emergency signal with the GPS coordinate data to a nearby vessel within a short range. The nearby vessel is equipped as a base station to receive the RF emergency signal and the person's GPS coordinate data and send out an RF broadcast signal of the person's position over a long range to the authorities or other rescue vessels. The personal unit is updated with the most current GPS data and recharged during inactive periods when the person on-board a vessel equipped as a base station. The personal unit sends the emergency signal until an acknowledgment signal is received from a base station, whereupon the personal unit is placed in a "Receive-Only" mode to save battery power. The base station is equipped with a GPS system that can be updated with the most current GPS data, so that it can calculate an accurate vector of approach to the person's position. The PELS system handles communications in the preferred GMDSS/DSC signal format (as defined by the International Maritime Organization).