The Cospas-Sarsat System is an internationally recognised programme that relays distress alerts from 406 MHz emergency beacons (ELTs, EPIRBs and PLBs) over a satellite network to ground stations located in many countries around the world. In order to work with the geostationary satellites which form the latest part of this system and to provide a location to the rescue services it is becoming increasingly popular to incorporate a GPS Receiver into these beacons to provide position information in the transmitted distress message. As these beacons are not used except in an emergency and this maybe years after they where produced and on the other side of the world the GPS Receiver does not have access to any valid ephemeris or almanac data and thus has to 'cold start'. At the same time these beacons are usually activated in less than ideal conditions, often under foliage, in rough seas or without a clear view of the sky making GPS reception difficult, especially when the receiver is required to cold start. It has been shown that the GPS Receivers in some beacons do not cope well under these conditions and that manufacturers and national type approval and testing authorities need a reliable means of testing their beacons to ensure that they will provide position information when required in an emergency. The Radio Technical Committee for Maritime Services (RTCM) in the USA has thus been developing new testing standards for Integral GPS Receivers in EPIRBs and PLBs in conjunction with Spirent Communications PLC using GPS Simulators to provide reliable repeatable test scenarios that can be included in both national and international standards for these beacons. This paper describes the background to this work, the present status of the work and provides examples of some of the issues and challenges faced in developing these products and the need for simulated scenarios, test methods and standards for testing GPS Receivers in harsh environments.
The use of GPS simulators to enhance the testing and evaluation of lifesaving emergency distress beacons
Die Verwendung von GPS-Simulatoren zur Verbesserung des Tests und der Evaluation von Lebensrettungs-Seenotbake
2007
13 Seiten, 4 Bilder, 5 Tabellen
Conference paper
Storage medium
English
NTRS | 1986
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