What is a Distress Beacon ?
A Distress Beacon is an electronic device that, when activated in a life threatening survival situation, assists SAR agencies to locate those in distress.
Who needs a Distress Beacon ?
If you are working or travelling in remote or hazardous areas, in particular if alone, you should consider purchasing a PLB. An Epirb is required by regulations to be carried by all vessels travelling more than 2 nautical miles offshore. Some activities also have mandatory requirements for individuals to also carry a PLB. Aviators also carry PLB's as well as in some cases having ELT's fitted.
What are the different tyes of 406 Beacons?
There are 3 main types of 406 Distress Beacons.
1) Emergency Position Indicating Radio Beacons ( EPIRB's ). These are mainly carried in marine vessels but in some cases are also used in land based applications.EPIRB's are designed to float in the water to optimise the signal to the satellite. Once activated, either manually or automatically, it is required to be able to operate for a minimum of 48 hours continuously.
2) Personal Locator Beacons. ( PLB's ) These are for personal use by bushwalkers, 4 X 4, climbers, canyoners, remote area workers, boat crews and aircrews.PLB's are designed for personal use in the Land, Marine and Aviation environment. They are used both in Industry and for recreation. PLB's are required to operate for a minimum of 24 hours continuously once activated.
3) Emergency Locator Transmitters ( ELT's ) used in the avaiation industry. These are usually permanently installed and can be impact activated.
Should I buy a GPS enabled Distress Beacon ?
To answer this, we first need to take a closer look at the satellite systems that receive and process the EPIRB signals. The original COSPAS-SARSAT system was built around polar orbiting satellites, about 600km above the earth, giving global coverage with automatic position fixing, using the Doppler effect. At higher latitudes, where the satellites tracks are close together, the "wait time" for a satellite pass is quite short - typically less than an hour in Northern Europe. However, closer to the equator, the wait time could be a couple of hours or more. More information...
How does my Distress Beacon work ?
When a distress beacon is activated, it transmits a uniquely coded signal that is detectable by overhead satellites. As the satellites orbit the Earth they "Listen" for any active beacons and then report to SAR authorities.
Beacons developed for the Cospas-Sarsat satellite system operate on 406 Mhz and use didital technology allowing the Beacon to Transmit a unique HexID or UIN code to identify the beacon. These beacons also transmit on the analogue 121.5 Mhz frequency to allow the " final stage of Homing in by rescue craft.
Satellite processing of the old 121.5 Mhz Beacons ceased on 1 Feburary 2009.
The Cospas-Sarsat system is divided into 2 segments.
1) The space segment which consists of " Distress Beacon Receivers" on Polar orbiting satellites and on satellites in geostationary orbit over the Equator.
2) The ground station segment is made up from a network of Local User Terminals (LUT's ) that are Ground receiving stations for the satellite transmissions with Mission Control Centres that analyse and pass the Distress alerts to regional Rescue Coordination centres.
In the Australian region there are 3 LUT's located at Albany WA, Bundaberg QLD, and Wellington NZ, These LUT's are controlled by the mission control centre located within the Rescue Coordination Centre in Canberra.
Alerts from 406 Mhz distress beacons can be received and processed by geo-stationary satellites and passed to RCC-Australia within minutes. If the Beacon has GPS position capability then an accurate position will be transmitted with the alert.
Non GPS beacons require detection by a Polar orbitting satellite before a position can be obtained.
What is my HexID or UIN ?
The HexID or UIN ( Unique Identity Number ) is a specific code programmed into each and every 406 Distress Beacon and it is this code that is transmitted when the Beacon is activated. When registering a distress beacon this code must be included in the registration as it is the only link between an individual distress beacon and the registration database.
Without the HexID the beacon cannot be registered.
The HexID is 15 characters long and is made up of hexadecimal numbers ( 0-9 ) and letters ( A-F ). The code can be found on the label of all distress beacons.
Useage and Activation:
Distress Beacons save lives. They should only be used when a "threat of grave and imminent danger exists".
In the event of an emergency all normal systems of communications should be tried first. eg: Radios, phones etc.
A distress beacon alert is usually detected by the RCC within minutes. If your distress beacon has an encoded GPS location capability, this information will also be sent to the RCC and your position then becomes known.If emergency contacts are aware of trip details, or trip details have been submitted on line, search operations can be commenced much sooner. If the RCC has to rely on Polar-Orbiting satellites to determine location of a beacon, the time to gain an accurate position may take longer, potentially delaying search operations.
Note: Polar Orbiting satellites over-fly the Australian region on average every 90 minutes but passes may be anywhere from minutes to 5 hours apart. to improve response times, ensure distress beacons are registered and emergency contacts are aware of trip details.
Even once a position is obtained, response times can vary dependant upon SAR units and rescource availability.
Other Tracking Devices:
There are a number of devices advertised as tracking devices with a distress function. Whilst systems such as "Spot","MobiLert" "Mobilarm"and others can all be classed as emergency devices care must be taken to understand their limitations and restrictions. Many alternate devices , although called distress beacons, only operate on Mobile phone networks or other Local area radio bands and therefore are subject to the same limitations.. If they are not Cospas-Sarsat compatible they will not comply with requirements that may be neccassary by law.
When determining which emergency beacon to purchase, keep in mind that some type of beacon is better than nothing. It's not a "should I buy" scenario, but a "which one should I buy?" because every boater should have either an EPIRB or a PLB. In some cases, it's not a bad idea to have both. Boats sink or capsize and people fall overboard even with the best planning,boating skills and experience in the world.