A 406 MHZ GLOBAL POSITIONING SYSTEM/EMERGENCY LOCATION TRANSMITTER FOR SEARCH AND RESCUE SATELLITE OPERATIONS

Abstract : The SARSAT (Search and Rescue Satellite) has demonstrated the use of 121.5/243.0 MHz beacons to locate the victims of aircraft and marine accidents. An experimental 406 MHz Emergency Location Transmitter (ELT) has been developed by NASA allowing a digital message containing identification and timing information as an alternative to the tone modulation signal provided on the 121.5/243.0 MHz ELT. Utilization of Global Positioning System (GPS) information with the 406 MHz ELT could greatly enhance the accuracy of the SARSAT system by including GPS position coordinates within the digital message. Location accuracies of less than 100 meters could be provided worldwide, which is ten times better than that available with the experimental 406 MHz ELT. (Author).