- Press Release
- Oct 1, 2022
Satellite Processing of 121.5/243 MHz Emergency Beacons to Be Terminated on Feb. 1, 2009
Cospas-Sarsat Program, a program that uses a satellite
constellation to relay distress alerts to search and rescue
authorities, announced at its 25th Council Session that it plans
to terminate satellite processing of distress signals from 121.5/243
MHz emergency beacons on Feb. 1, 2009. Mariners, aviators,
and individuals using emergency beacons will need to switch to
those operating at 406
MHz if they want to be detected by satellites.
The termination of 121.5/243 MHz processing
is planned far enough into the
future to allow users adequate time for the transition to the
406 MHz beacon. The Cospas-Sarsat Program has approved a plan
for the phasing out of 121.5/243 MHz satellite alerting services
that address practical aspects of the phaseout. This decision
is a follow-on to Cospas-Sarsat’s announcement last year that
it would no longer carry 121.5/243 MHz search and rescue instruments
starting in 2006 for Russian satellites and 2009 for the U.S.
satellites, operated by the Commerce
Department‘s National Oceanic
and Atmospheric Administration.
The Cospas-Sarsat Program made the decision
to terminate 121.5/243 MHz satellite alerting services, in part,
in response to guidance from the International
Maritime Organization and the International
Civil Aviation Organization. These two agencies of the United
Nations are responsible for regulating the safety on international
transits of ships and aircraft, respectively, and handling international
standards and plans for maritime and aviation search and rescue.
More than 180 nations are members of IMO and ICAO.
Another major factor in the decision to
stop satellite processing of 121.5/243 MHz signals is due to
problems in this frequency band which inundate search and rescue
authorities with false alerts, adversely impacting the effectiveness
of lifesaving services. Although the 406 MHz beacons cost more,
they provide search and rescue agencies with more reliable and
complete information to do their job more efficiently and effectively.
NOAA, along with the U.S.
Coast Guard, U.S. Air Force
and the National Aeronautics and
Space Administration, is responsible for implementing the
Cospas-Sarsat Program at the national level in the United States.
The implication of this Cospas-Sarsat decision
is that users of beacons that send distress alerts on 121.5 /243
MHz should eventually begin using beacons operating on 406 MHz
if the alerts are to be detected and relayed via satellites.
Meanwhile, anyone planning to buy a new distress beacon may wish
to take the Cospas-Sarsat decision into account.
The three types
of beacons in use are: emergency locator transmitters (ELTs),
used on airplanes; emergency position-indicating radio beacons
(EPIRBs), used on boats; and personal locator beacons (PLBs)
used by land-based persons such as hikers.