A GEOLUT is a ground receiving station in the Cospas-Sarsat System that receives and processes 406 MHz distress beacon signals which have been relayed by a Cospas-Sarsat geostationary satellite. Due to the extremely large continuous coverage footprint provided by each geostationary satellite, GEOLUTs are able to produce near instantaneous alerting over extremely large areas. However, due to the fact that the satellite remains stationary with respect to distress beacons, GEOLUTs are not able to determine beacon locations using Doppler processing techniques. In view of this, 406 MHz beacons with location protocols allow for the encoding of position data in the transmitted 406 MHz message, thus providing for quasi-real time alerting with position information via the GEOSAR system.

Salient Features :

• Formats: NRZ - L bi-phase modulation of sub-carriers (62.5 to 140 KHz)
• Short (144 bits) and long (288 bits) message support @ 400 bps
• Simultaneous detection of up to 25 beacons
• Successful decoding at C/No of 26 dBHz
• Processor tracks the individual sub-carrier frequencies and bit rate drifts
• Interfaces: Keyboard, Remote, Ethernet
• Message bit error corrections using BCH decoding
• Visualization of message bits on MS-Windows
• Optimum data transfer over PCI bus

Block Diagram :