PLBs - Personal Locator Beacons

A PLB is the only link between you and civilization

What is a PLB?

PLB stands for Personal Locator Beacon. A 406 MHz PLB is a battery-powered emergency transmitter which, when activated, sends a digitally encoded signal to the Cospas-Sarsat Satellite System. They are predominatly intended for personal use on land with bushwalkers, adventurers, 4X4 Explorers.They are also finding a range of applications as personal emergency devices in man overbaord situations. A Personal Locator Beacon can take rescue times from days to minutes.

Cospas-Sarsat

Thanks to the combined efforts of Canada, France, Russia and the US, an international satellite system helps locate people in distress in isolated areas around the globe. Four Cospas (Cosmicheskaya Sistyema Poiska Avariynich Sudov)-Sarsat (Search and Rescue Satellite-Aided Tracking) satellites continuously circle around our planet in Low-Earth Orbits (LEO) over the Poles.

The Russian geostationary NADEZHDA navigation satellites carry the Cospas repeater packages and NOAA weather satellites, also geostationary, carry Sarsat packages.

Two different satellite systems to capture the signal from Personal Locator Beacons

GEO satellites continually view large areas of the Earth from approximately 70 degrees North to 70 degrees South latitudes and can provide immediate alerting and identification of a 406 MHz beacon. They cannot determine the location of a PLB using Doppler processing, because they are "stationary".

The signals received by LEO satellites are relayed to a network of LUTs (Local User Terminals) that locate the PLB by measuring the Doppler shift caused by the motion of the satellite with respect to the beacon. This process can locate a 406 MHz beacon within an accuracy of approximately 3 miles (5 km).

Not good enough

It can take up to 90 minutes for a LEO satellite to come overhead and to get a position of a PLB that sends a distress signal. In some cases this could be too long to save someone.

A GPS receiver incorporated in a PLB

This gives a huge amelioration for two reasons:

The location accuracy is much better than the accuracy obtained by the Doppler shift measurements of the LEO satellites.
The PLB sends its GPS coordinates with the distress signal, so no need to wait for the LEO satellites anymore.
GPS Vs Non-GPS Beacon

Two requirements added to Personal Locator Beacon standards

The U.S. added two notable requirements to the international Personal Locator Beacon standards. They must include a 25 milliwatt 121.5 MHz analog homing signal. Inserted into the homing signal at the insistence of the FAA is a Morse code P to distinguish a PLB from an ELT (Emergency Locator Transmitters), as used in aviation.

PLB registration

Your PLB must be registered in your country of residence. Each Personal Locator Beacon is equipped with a UIN (Unique Identifying Number) This number is a 15 digit alpha-numeric code. This code is what is transmitted in the electronic burst to the satellites. The UIN is linked to a computer database. The electronic burst provides Search and Rescue with your location, while the UIN links to the database and provides your name, address, phone number and any pertinent information such as medical problems, of which Search and Rescue should be aware. When you buy a Personal Locator Beacon, it is imperative that you register it. In doing so, they will tie all your personal information into the 15 digit UIN. That way, when your beacon is activated any where on the Planet, Search and Rescue will know, who you are, where you are and how to handle any pre-existing medical problems when they reach you.

Mainstay is very focused on our primary goal of providing professional technical services as a V.A.S. (Value Added Service) to every product that we sell. Throughout our website you will see V.A.S.

For example with all Epirb's, PLB's and ELT's purchased from Mainstay the purchase will automatically include Testing and Certification service for the following year. This "value add" represents a saving of over $100.