Satellite-based search and rescue system for satellite navigation system e.g. global positioning system, has base segment transmitting recall message from satellites to emergency call transmitter after reception of emergency call message

摘要

The system has a space segment (10) comprising satellites (12, 14, 16, 18), and a base segment (20) comprising base stations (22). The satellites receive an emergency call message (26) from an emergency call transmitter (28), and transmit the message to the base stations. The message contains the satellites receiving a recall message (30) from the base segment for acknowledging the reception of the emergency call message from the rescue system. The base segment transmits the recall message from the satellites to the emergency call transmitter after the reception of the emergency call message.