How does Fast Find work?

Fast Find has two radio transmitters which start transmitting when you activate your beacon. One transmitter operates at 406 MHz which transmits alerts via satellites. The other operates at 121.5 MHz which transmits a signal which can be received by over-flying aircraft and Search and Rescue homing receivers.

Ground stations track the satellites and process the distress signals to obtain a location of the distress. The processed information is then forwarded to a Mission Control Centre where it is combined with Fast Find registration information and passed to a Rescue Coordination Centre which alerts the appropriate Search and Rescue authorities. Successive satellite passes refine and confirm the original information.

Fast Find 210 with inbuilt GPS receivers determine their own geographical position and transmit it as part of the distress alert signal.

Fast Find has a secondary 121.5 MHz homing transmitter. This transmits on the 121.5 MHz internationally recognised aviation guard channel. If an aircraft hears an activated beacon, it will often make a report to the aviation authority which will pass this information to the Rescue Coordination Centre. When the rescue services get close they can "home in" on the 121.5 MHz signal using direction finding techniques.

The Cospas-Sarsat 406 MHz satellite system has global coverage that provides a typical time to alert notification of between approximately 3 and 45 minutes. The geographical location of a Fast Find (with inbuilt GPS receiver) can normally be resolved within 5 minutes and 45 minutes for a non-GPS beacon. The time to alert is dependant on which satellites are in view in the sky at the time of Fast Find activation. Non-GPS PLBs rely on passing orbiting satellites to determine an approximate position, this can take longer and the resolved position is less accurate than can be achieved compared to a GPS Fast Find.

406 is the all-important frequency for distress beacons operating with satellite systems. The Cospas-Sarsat 406 MHz beacons have been specifically designed for use with the 'LEOSAR' satellite system.
The frequencies, between 406.0 - 406.1 MHz are stable and include a digital message which allows the transmission of encoded data such as unique beacon identification. That's the information you have supplied when you registered your Fast Find.

The 406 MHz system is composed of:

• 406 MHz radiobeacons like the Fast Find. A number of similar products using the same
  technology as well. These include those beacons carried aboard ships (EPIRBs), aircraft
  (ELTs), or used as personal locator beacons (PLBs);
• polar-orbiting satellites in low Earth which orbit from the LEOSAR system and geostationary
  satellites from the GEOSAR system; and
• the associated LUTs (Local User Terminals) for the respective satellite systems . These are on
  the ground.

When the satellite system receives 406 MHz beacon signals, the processor in the Fast Find recovers the digital data from the beacon signal and processes it as digital data. It is then transferred to the ground units for processing and relaying to search and rescue stations.

For an full explanation, visit the Cospas-Sarsat web site at http://www.cospas-sarsat.org.

The 121.5 MHz system:

121.5MHz is a homing signal. It is a secondary signal that is transmitted by the Fast Find, so that when a search party is in the near vicinity it will pick up the signal and immediately calculate which direction it is coming from. This enables the team to get to the victim directly and quickly.

121.5MHz was until recently used as a distress signal via the satellite system but has now been discontinued. Only the 406 MHz transmission is now used.

For an full explanation, visit the Cospas-Sarsat web site at http://www.cospas-sarsat.org.