Cospas-Sarsat is an international satellite-based search and rescue (SAR) distress alert detection and information distribution system, established by Canada, France, the United States, and the former Soviet Union in 1979. It is best known as the system that detects and locates emergency beacons activated by aircraft, ships and backcountry hikers in distress. Over the years many countries have joined the project, either as providers of ground segments or as user states.
As of 2011, 26 countries (Algeria, Argentina, Australia, Brazil, Chile, China (P.R.of), Greece, India, Indonesia, Italy, Japan, Korea (Rep.of), New Zealand, Nigeria, Norway, Pakistan, Peru, Saudi Arabia, Singapore, South Africa, Spain, Thailand, Turkey, UAE, UK, Vietnam) and two organizations (ITDC of Chinese Taipei and Hong Kong, China) are providers of ground segments, while 11 countries are user states (Cyprus, Denmark, Finland, Germany, Madagascar, Netherlands, Poland, Serbia, Sweden, Switzerland, Tunisia). Cospas-Sarsat is based in Montréal, Québec, Canada, and is headed by Steven Lett of the United States.
The system consists of a ground segment and a space segment:
The system consists of a ground segment and a space segment:
- Distress radiobeacons to be activated in a life-threatening emergency
- SAR signal repeaters (SARR) and SAR signal processors (SARP) aboard satellites
- Satellite downlink receiving and signal processing stations called LUTs (local user terminals)
- Mission Control Centres that distribute to Rescue Coordination Centres distress alert data (particularly beacon location data) generated by the LUTs
- Rescue Coordination Centres that facilitate coordination of the SAR agency and personnel response to a distress situation.
The space segment of the Cospas-Sarsat system currently consists of SARR instruments aboard 5 geosynchronous satellites called GEOSARs, and SARR and SARP instruments aboard 6 low-earth polar orbit satellites called LEOSARs.
The space segment of the Cospas-Sarsat system currently consists of SARR instruments aboard 5 geosynchronous satellites called GEOSARs, and SARR and SARP instruments aboard 6 low-earth polar orbit satellites called LEOSARs.
Background information
The first system satellite 'COSPAS-1' (Kosmos 1383) was launched from Plesetsk Cosmodrome on June 29, 1982. Cospas-Sarsat began tracking the two original types of distress radiobeacons in September, 1982. Specifically, these were:
- EPIRBs (Emergency Position-Indicating Radio Beacons), which signal maritime distress; and
- ELTs (Emergency Locator Transmitters), which signal aircraft distress
More recently, a new type of distress radiobeacon became available (in 2003 in the USA):
More recently, a new type of distress radiobeacon became available (in 2003 in the USA):
- PLBs (Personal Locator Beacons), are for personal use and are intended to indicate a person in distress who is away from normal emergency services.
The four founding countries led development of the 406 MHz marine EPIRB for detection by the system. The EPIRB was seen as a key advancement in SAR technology in the perilous maritime environment. Prior to the founding of Cospas-Sarsat, the aviation community had already been using the 121.5 MHz frequency for distress. ELTs for general aviation were constructed to transmit on 121.5 MHz, a frequency monitored by airliners and other aircraft. Military aircraft beacons were manufactured to transmit at 243.0 MHz, in the band commonly used by military aviation. Early in its history, the Cospas-Sarsat system was engineered to detect beacon-alerts transmitted at 406 MHz, 121.5 MHz and 243.0 MHz. More recently, the Cospas-Sarsat system has been designed to detect only alerts transmitted at 406 MHz. This allows the system to be optimized for the increasingly sophisticated 406 MHz beacons, and avoids problems (including false alerts) from the less-sophisticated legacy 121.5 MHz and 243.0 MHz beacons. Many ELTs include both a 406 MHz transmitter, for satellite detection, and a 121.5 MHz transmitter that can be received by local search crews using direction-finding equipment.
The four founding countries led development of the 406 MHz marine EPIRB for detection by the system. The EPIRB was seen as a key advancement in SAR technology in the perilous maritime environment. Prior to the founding of Cospas-Sarsat, the aviation community had already been using the 121.5 MHz frequency for distress. ELTs for general aviation were constructed to transmit on 121.5 MHz, a frequency monitored by airliners and other aircraft. Military aircraft beacons were manufactured to transmit at 243.0 MHz, in the band commonly used by military aviation. Early in its history, the Cospas-Sarsat system was engineered to detect beacon-alerts transmitted at 406 MHz, 121.5 MHz and 243.0 MHz. More recently, the Cospas-Sarsat system has been designed to detect only alerts transmitted at 406 MHz. This allows the system to be optimized for the increasingly sophisticated 406 MHz beacons, and avoids problems (including false alerts) from the less-sophisticated legacy 121.5 MHz and 243.0 MHz beacons. Many ELTs include both a 406 MHz transmitter, for satellite detection, and a 121.5 MHz transmitter that can be received by local search crews using direction-finding equipment.
The design of distress radiobeacons as a whole has evolved significantly since 1982; the newest 406 MHz beacons incorporate GPS receivers; such beacons transmit highly accurate positions of distress almost instantly to SAR agencies via the GEOSAR satellites. The advent of such beacons has created the current motto of SAR agencies --- "Taking the 'Search' out of Search and Rescue." (See MEOSAR below.)
COSPAS (КОСПАС) is an acronym for the Russian words "Cosmicheskaya Sistema Poiska Avariynyh Sudov" (Космическая Система Поиска Аварийных Судов), which translates to "Space System for the Search of Vessels in Distress". SARSAT is an acronym for Search And Rescue Satellite-Aided Tracking.
Cospas-Sarsat is an element of the Global Maritime Distress Safety System (GMDSS). Automatic-activating EPIRBs are now required on International Convention for the Safety of Life at Sea (SOLAS) ships, commercial fishing vessels, and all passenger ships, are designed to transmit to a Rescue Coordination Centre a vessel identification and an accurate location of the vessel from anywhere in the world.
COSPAS (КОСПАС) is an acronym for the Russian words "Cosmicheskaya Sistema Poiska Avariynyh Sudov" (Космическая Система Поиска Аварийных Судов), which translates to "Space System for the Search of Vessels in Distress". SARSAT is an acronym for Search And Rescue Satellite-Aided Tracking.
Cospas-Sarsat is an element of the Global Maritime Distress Safety System (GMDSS). Automatic-activating EPIRBs are now required on International Convention for the Safety of Life at Sea (SOLAS) ships, commercial fishing vessels, and all passenger ships, are designed to transmit to a Rescue Coordination Centre a vessel identification and an accurate location of the vessel from anywhere in the world.
System composition
The ground segment of the system consists of:
- Distress radiobeacons
- Satellite downlink receiving and signal processing stations called local user terminals (LUT)
- Mission Control Centres that distribute distress alert data generated by the LUTs
- Joint Rescue Coordination Centers (also referred to as Rescue Coordination Centres) that coordinate SAR response to a distress situation
The space segment of the system consists of:
- SAR signal processors aboard satellites
Space segment
The Cospas-Sarsat system space segment consists of SARR/SARP instruments aboard:
- 5 geosynchronous satellites called GEOSARs, and
The Cospas-Sarsat system space segment consists of SARR/SARP instruments aboard:
- 5 geosynchronous satellites called GEOSARs, and
- 6 low-earth polar orbit satellites LEOSARs.
A SARR/SARP instrument is a small package, typically attached to a satellite that is being launched primarily for another purpose. These SARR/SARP are considered a secondary payload onboard satellites with a generally unrelated scientific or telecommunications purpose. See the technical information below for lists of SARR/SARP and their associated satellites.
Ground segment
The satellites are monitored by receiving stations equipped with satellite-tracking satellite dishes called local user terminals (LUT). Each nation's LUTs are monitored by an MCC (Mission Control Centre), a data distribution clearinghouse that distributes alert information to the various rescue coordination centres.
The satellites are monitored by receiving stations equipped with satellite-tracking satellite dishes called local user terminals (LUT). Each nation's LUTs are monitored by an MCC (Mission Control Centre), a data distribution clearinghouse that distributes alert information to the various rescue coordination centres.