Implementación de decodificadores de bajo coste de radiobalizas del sistema COSPAS-SARSAT

Abstract

The Cospas-Sarsat Programme assist search and rescue activities on a worldwide basis by providing accurate, timely, and reliable alert and location data in case of a distress. The System is composed of radiobeacons, which transmit signals during distress situations; satellites in geostationary and low-altitude Earth orbits; ground receiving stations and mission control centers. To ensure the effectiveness and reliability of this System, radio beacons have to accomplish the Cospas-Sarsat standards and have to be periodically checked using expensive radiobeacon decoders. This paper presents a low cost implementation of a radiobeacon decoder based on a multipurpose FM receiver (avoiding the need to use coherent digital demodulators), an amplifier, a Schmitt Trigger, a microcontroller and a PC. A graphical user interface has also been developed to extract and display all the relevant information included in the radiobeacon digital message. The excellent performance of this low cost system has been validated using commercial radiobeacon decoders.