122:
in the early 1970s. The frequency and signal format used by the ELT beacons was not designed for satellite detection, which resulted in a system with poor location detection abilities and long delays in detection of activated beacons. The satellite detection network was built after the ELT beacons were already in general use, with the first satellite not being launched until 1982, and even then, the satellites only provided detection, with location accuracy being roughly 20 km (12 mi). The technology was later expanded to cover use on vessels at sea (EPIRB), individual persons (PLB), and starting in 2016, maritime survivor locating devices (MSLD). All have migrated from using 121.500 MHz as their primary frequency to using 406 MHz, which was designed for satellite detection and location.
1800:
1569:
Canadian registered aircraft to either a 406 MHz ELT or an alternate means system; however, elected officials have overruled the recommendation of
Transport Canada for the regulation and have asked for a looser regulation to be drafted by Transport Canada. Recent information indicates Transport Canada may permit private, general aviation flight with only an existing 121.5 MHz ELT if there is a placard visible to all passengers stating to the effect that the aircraft does not comply with international recommendations for the carriage of the 406 MHz emergency alerting device and is not detectable by satellites in the event of a crash.
1495:
1965:
1736:
aviation aircraft to install ELTs by Dec. 30, 1973, and it preempted all the state ELT laws. The federal ELT law left the matter of alerting vague, although the initial idea was alerting by over flying aircraft which could receive an ELT's 75-milliwatt signal from 50 nautical miles away. The law set the compliance dates as one year after passage for newly manufactured or imported aircraft (December 30, 1971), and three years for existing aircraft (December 30, 1973). In response to the law, the
2023:
2987:
356:
4851:
1532:, and in the specification the alarm signal is defined as an AM signal (A3X and/or N0N emissions), containing a swept tone ranging from 1600 Hz to 300 Hz (downwards), with 2-4 sweeps per second. When activated, 406 MHz units transmit a 0.5 second, 5-watt digital burst every 50 seconds, varying within a span of ±2.5 seconds somewhat randomly, so as to avoid multiple ELTs always having their beacons synchronized.
557:. Also, two satellite passes per beacon were used. This eliminated false alarms by using two measurements to verify the beacon's location from two different bearings. This prevented false alarms from VHF channels that affected a single satellite. Regrettably, the second satellite pass almost doubled the average time before notification of the rescuing authority. However, the notification time was much less than a day.
6190:
5108:
5118:
6200:
45:
1778:
water-sensing device or a submerged-sensing device that activates and releases a floating beacon after it has been submerged in between 1 and 4 meters of water. In addition to the 406 MHz signal mandated by C/S T.001, the IMO and ICAO require an auxiliary 121.5 MHz at another frequency in order to support the large installed base of 121.5 MHz direction finding equipment.
6179:
2999:
6210:
4377:, When one enters the transmitted (i.e. GPS-location-included) 15-hex into the decoder, the unmodified 15-hex ID is printed at the bottom of the output of the Beacon Decoder page. This method can be used to confirm that a beacon is encoding the correct 15-hex ID (as printed on the side of the beacon) into its distress messages. URL updated 26 March 2021.
53:
509:
million and the signals were broadcast using only 75–100 milliwatts of power. Coverage was partial because the satellite had to be in view of both the beacon and a ground station at the same time; the satellites did not store and forward the beacon's position. Coverage in polar and
Southern Hemisphere areas was poor.
1887:– This entered service in 1997 and service ended 1 December 2006; all former users have switched to Category I or II 406 MHz EPIRBs. These beacons were float-free, automatically activated EPIRBs operated on 1646 MHz and were detectable by the Inmarsat geostationary satellite system, and were recognized by
2963:
latitude and longitude, so they can be used for both normal and emergency tracking. They also are routed to the
Internet, where they are archived for some period of time, and viewable by others. There are several emergency packet types that can indicate distress. Since it is part of the amateur radio
2242:
The repetition period shall not be so stable that any two transmitters appear to be synchronized closer than a few seconds over a 5-minute period. The intent is that no two beacons will have all of their bursts coincident. The period shall be randomised around a mean value of 50 seconds, so that time
2174:
position into the signal. All beacons are located by
Doppler triangulation to confirm the location. The digital data identifies the registered user. A phone call by authorities to the registered phone number often eliminates false alarms (false alarms are the typical case). If there is a problem, the
1948:
Once deployed, EPIRBs can be activated, depending on the circumstances, either manually (crewman flicks a switch) or automatically (when water contacts the unit's "sea-switch".) All modern EPIRBs provide both methods of activation and deployment, and thus are labelled "Manual and
Automatic Deployment
1198:
The US Coast Guard web page for EPIRBs states: "You may be fined for false activation of an unregistered EPIRB. The US Coast Guard routinely refers cases involving the nondistress activation of an EPIRB (e.g., as a hoax, through gross negligence, carelessness, or improper storage and handling) to the
300:
The LEOSAR system calculates the location of distress events using
Doppler processing techniques. Doppler processing is based upon the principle that the frequency of the distress beacon, as "heard" by the satellite instrument, is affected by the relative velocity of the satellite with respect to the
2149:
All ELTs, all PLBs, and most EPIRBs are required to have a low-power homing signal, that is identical to the original 121.500 MHz VHF beacon signal. However, due to the extremely large number of false alarms that the old beacons generated, the transmit power was greatly reduced, and because the
1730:
Carriage requirements for emergency locator beacons on most US non-jet powered fixed-wing civil aircraft became law on
December 29, 1970, with the signing of Senate bill S.2193, "The Occupational Safety and Health Act of 1970," Public Law 91-596. as a last-minute rider to the Occupational Safety and
1568:
Although monitoring of 121.5 and 243 MHz (Class B) distress signals by satellite ceased in
February 2009, the FAA has not mandated an upgrade of older ELT units to 406 MHz in United States aircraft. Transport Canada has put forward a proposed regulatory requirement that requires upgrade to
332:
Cospas-Sarsat defines standards for beacons, auxiliary equipment to be mounted on conforming weather and communication satellites, ground stations, and communications methods. The satellites communicate the beacon data to their ground stations, which forward it to main control centers of each nation
80:
boaters in distress and in need of immediate rescue. In the event of an emergency, such as a ship sinking or medical emergency onboard, the transmitter is activated and begins transmitting a continuous 406 MHz distress radio signal, which is used by search-and-rescue teams to quickly locate the
2129:
The most important aspect of a beacon in classification is the mode of transmission. There are two valid transmission modes: digital and analog. Where digital usually has a longer range, analog is more reliable. Analog beacons are useful to search parties and SAR aircraft, though they are no longer
1463:
Despite the switch to 406 MHz, pilots and ground stations are encouraged to continue to monitor for transmissions on the emergency frequencies, as most 406 MHz beacons are required to be equipped with 121.5 "homers." Furthermore, the 121.5 MHz frequency continues remains the official
582:
Emergency beacons operating on 406 MHz transmit a unique 15-, 22-, or 30-character serial number called a hex code. When the beacon is purchased, the hex code should be registered with the relevant national (or international) authority. After one of the mission control centers has detected the
565:
Receivers are auxiliary systems mounted on several types of satellites. This substantially reduces the program's cost. The weather satellites that carry the SARSAT receivers are in "ball of yarn" orbits, inclined at 99 degrees. The longest period that all satellites can be out of line-of-sight of a
552:
Russia developed the original system, and its success drove the desire to develop the improved 406-MHz system. The original system was a brilliant adaptation to the low-quality beacons, originally designed to aid air searches. It used just a simple, lightweight transponder on the satellite, with no
545:
If the beacon's frequency is more precise, it can be located more precisely, saving search time, so modern 406-MHz beacons are accurate to 2 parts per billion, giving a search area of only 2 km, compared to the older beacons accurate to 50 parts per million that had 200 km of search area.
386:
Once the satellite data is received, less than a minute is needed to forward them to any signatory nation. The primary means of detection and location is by the COSPAS-SARSAT satellites. However, additional means of location are frequently used. For example, the FAA requires that all pilots monitor
121:
The first form of these beacons was the 121.5 MHz ELT, which was designed as an automatic locator beacon for crashed military aircraft. These beacons were first used in the 1950s by the U.S. military, and were mandated for use on many types of commercial and general-aviation aircraft beginning
2030:
Personal
Locator Beacons (PLBs) are designed for use by individuals who are hiking, kayaking, or conducting other activities on land or water where they are not in or associated with an aircraft or vessel that is equipped with its own ELT or EPIRB. As with EPIRBs, the RTCM maintains specifications
1785:(Radio Technical Commission for Maritime Services) maintains specifications specific to EPIRB devices. The alarm signal is defined as an AM signal (A3X and/or N0N emissions), containing a swept tone ranging from 1600 Hz to 300 Hz (either upwards or downwards), with 2-4 sweeps per second.
573:
Some geosynchronous satellites have beacon receivers. Since the end of 2003, there are four such geostationary satellites (GEOSAR) that cover more than 80% of the surface of the earth. As with all geosynchronous satellites, they are located above the equator. The GEOSAR satellites do not cover the
98:
and broadcasts its position, usually accurate within 100 m (330 ft), to facilitate location. Previous emergency beacons without a GPS can only be localized to within 2 km (1.2 mi) by the COSPAS satellites and relied heavily upon the 121.5 MHz homing signal to pin-point the
1777:
Emergency
Position-Indicating Radio Beacons (EPIRBs) are a development of the ELT designed specifically for use on boats and ships, and basic models tend to be less expensive than ELTs (average cost is $ 800). As such, instead of using an impact sensor to activate the beacon, they typically use a
485:
An intermediate technology 406-MHz beacon (now mostly obsolete in favor of GPS-enabled units) has worldwide coverage, locates within 2 km (12.5 km search area), notifies kin and rescuers in 2 hours maximum (46 min average), and has a serial number to look up phone numbers, etc. This can
2246:
Preliminary specification for second-generation beacons. From beacon activation a total of initial transmissions shall be made separated by fixed intervals. The first transmission shall commence within seconds of beacon activation. Transmissions shall then occur at nominally second intervals
1876:
ch15/16. Manually activated, these beacons operate on maritime channels only, and therefore are not detectable by satellite or normal aircraft. Designed for small crafts operating close to shore, this type was only recognized in the United States. Use of these units was phased out in 1999. These
1588:
ELTs were first mandated in 1973 by FAA technical standard order (TSO-C91). The original TSO-C91, and updated TSO-C91A were officially deprecated as of February 2, 2009, when reception of the 121.5 MHz signal was deactivated on all of the SAR satellite, in favor of the C126 ELT models, with
600:
Registration information allows SAR agencies to start a rescue more quickly. For example, if a shipboard telephone number listed in the registration is unreachable, it could be assumed that a real distress event is occurring. Conversely, the information provides a quick and easy way for the SAR
529:
processing. Local-user terminals (LUTs) detecting nongeostationary satellites interpret the Doppler frequency shift heard by LEOSAR and MEOSAR satellites as they pass over a beacon transmitting at a fixed frequency. The interpretation determines both bearing and range. The range and bearing are
508:
These distress signals could be detected by satellite over only 60% of the earth, required up to 6 hours for notification, located within 20 km (12 mi) (search area of 1200 km), were anonymous, and could not be located well because their frequency is only accurate to 50 parts per
1735:
added the unrelated beacon language as a rider to the bill, which became section 31 of the law. (Earlier in the session he tried to add the requirements as an amendment to House bill H.R. 14465, the "Airport and Airways Development Act of 1969," but was unsuccessful.) It required most general
1452:
SAR satellite system. This affects all maritime beacons (EPIRBs), all aviation beacons (ELTs) and all personal beacons (PLBs). In other words, Cospas-Sarsat has ceased satellite detection and processing of 121.5/243 MHz beacons. These older beacons are now only detectable by ground-based
1447:
Because of the extremely high numbers of false alerts on the 121.500 MHz frequency (over 98% of all COSPAS-SARSAT alerts), the IMO eventually requested for a termination of COSPAS-SARSAT processing of 121.5 MHz signals. The ICAO Council also agreed to this phase-out request, and the
93:
organization, which performs the search and rescue. As Search and Rescue approach the search areas, they use Direction Finding (DF) equipment to locate the beacon using the 121.5 MHz homing signal, or in newer EPIRBs, the AIS location signal. The basic purpose of this system is to help
476:
However, rescue cannot begin until a Doppler track is available. The COSPAS-SARSAT specifications say that a beacon location is not considered "resolved" unless at least two Doppler tracks match or a Doppler track confirms an encoded (GPS) track. One or more GPS tracks are not sufficient.
94:
rescuers find survivors within the so-called "golden day" (the first 24 hours following a traumatic event) during which the majority of survivors can usually be saved. The feature distinguishing a modern EPIRB, often called GPIRB, from other types of emergency beacon is that it contains a
1668:, ground testing of A-, B-, and S-type ELTs is to be done within the first 5 minutes of each hour. Testing is restricted to three audio sweeps. Type I and II devices (those transmitting at 406 MHz) have a self test function and must not be activated except in an actual emergency.
2054:
lb). They can be purchased from marine suppliers, aircraft refitters, and (in Australia and the United States) hiking supply stores. The units have a useful life of 10 years, operate across a range of conditions −40 to 40 °C (−40 to 104 °F), and transmit for 24 to 48 hours.
2247:
until minutes after beacon activation. The repetition period between the start of two successive transmissions shall be randomised around the stated nominal value, so that intervals between successive transmissions are randomly distributed over ± seconds. Subsequent transmissions .
1572:
In the case of 121.5 MHz beacons, the frequency is known in aviation as the "VHF Guard" emergency frequency, and all U.S. civilian pilots (private and commercial) are required, by FAA policy, to monitor this frequency when it is possible to do so. The frequency can be used by
2284:. The 15-hex ID can only be reprogrammed by certified distress radiobeacon technicians. The national authority uses this number to look up phone numbers and other contact information for the beacon. This is crucial to handle the large number of false alarms generated by beacons.
1936:
For a marine EPIRB to begin transmitting a signal (or "activate") it first needs to come out of its bracket (or "deploy"). Deployment can happen either manually where someone must physically remove it from its bracket or automatically where water pressure will cause a
1715:
article covered the death of 16-year-old Carla Corbus, who survived, though badly injured, along with her mother, for 54 days after the plane her step-dad was flying crashed in the Trinity Alps of California in March 1967. He was lost and died in the woods looking for
2484:(and most jurisdictions in Europe) no special license is required to operate an EPIRB. In some countries (for example the Netherlands) a marine radio operators license is required. The following paragraphs define other requirements relating to EPIRBs, ELTs, and PLBs.
125:
Since the inception of Cospas-Sarsat in 1982, distress radio beacons have assisted in the rescue of over 50,000 people in more than 7,000 distress situations. In 2010 alone, the system provided information used to rescue 2,388 persons in 641 distress situations.
574:
polar caps. Since they see the Earth as a whole, they see the beacon immediately, but have no motion, and thus no Doppler frequency shift to locate it. However, if the beacon transmits GPS data, the geosynchronous satellites give nearly instantaneous response.
619:
Beacons operating on 121.5 MHz and 243.0 MHz only simply transmit an anonymous siren tone, thus carry no position or identity information to SAR agencies. Such beacons now rely solely on the terrestrial or aeronautical monitoring of the frequency.
1838:
Class A – 121.5/243 MHz. Float-free, automatically activating. Due to limited signal coverage and possible lengthy delays in signal recognition, the U.S. Coast Guard no longer recommends use of this type. These devices have been phased out by the U.S.
2768:
IEC 61097-2: Global maritime distress and safety system (GMDSS) - Part 2: COSPASSARSAT EPIRB - Satellite emergency position indicating radio beacon operating on 406 MHz - Operational and performance requirements, methods of testing and required test
2612:
1761:
After problems with the C-91 ELTs, The FAA responded to the defective early ELTs by outlawing the installation of C-91 ELTs and certifying C91a ELTs with an improved gravity switch, improved crash and fire-worthy casing, and batteries that work in colder
89:, which can detect emergency beacons anywhere on Earth transmitting on the distress frequency of 406 MHz. The satellites calculate the position or utilize the GPS coordinates of the beacon and quickly passes the information to the appropriate local
553:
digital recorders or other complexities. Ground stations listened to each satellite as long as it was above the horizon. Doppler shift was used to locate the beacon(s). Multiple beacons were separated when a computer program analysed the signals with a
465:
The 406-MHz beacons with GPS track with a precision of 100 m in the 70% of the world closest to the equator, and send a serial number so the responsible authority can look up phone numbers to notify the registrant (e.g., next-of-kin) in four minutes.
616:. Despite the clear benefits of registration, an unregistered 406-MHz beacon is very substantially better than a 121.5-MHz beacon, because the hex code received from a 406-MHz beacon confirms the authenticity of the signal as a real distress signal.
290:" (Космическая Система Поиска Аварийных Судов), which translates to "space system for the search of vessels in distress". A consortium of USSR, the U.S., Canada, and France formed the organization in 1982. Since then, 29 other countries have joined.
325:
Global Navigation Satellite System (GNSS) for EPIRBs, PLBs, and EPIRBs to utilize the new Return Link Service or RLS that provides a confirmation message from Search and Rescue back to the beacon to let the survivors know their distress message was
3449:
1909:
As part of the United States efforts to prepare beacon users for the end of 121.5 MHz frequency processing by satellites, the FCC has prohibited the use of 121.5 MHz EPIRBs as of January 1, 2007 (47 CFR 80.1051). See
1554:") have not been permitted for new installations since June 21, 1995; the replacing standard was TSO-C91a. Furthermore, TSO-C91/91a ELTs are being replaced / supplemented by the TSO C126 406 MHz ELT, a far superior unit.
2964:
service, it costs nothing to transmit on and uses the extensive network, however, one must be a licensed amateur radio operator. There is also no guarantee that an APRS distress packet report would be seen or handled by
2883:(bold are Canadian-required frequencies). Although sometimes defined in the same standards as the COSPAS-SARSAT beacons, MSLDs can not be detected by that satellite network, and are instead intended only for short-range
1386:
In the UK, the Distress and Diversion Cell of the Royal Air Force provides continuous monitoring of 121.5 MHz and 243.0 MHz, with autotriangulation from a network of terrestrial receivers on both frequencies.
2217:
characters. The unique 15-character digital identity (the 15-hex ID) is hard-coded in the firmware of the beacon. The 406.025 MHz carrier signal is modulated plus or minus 1.1 radians with the data encoded using
1480:, the FAA declined to do so. Citing two recent accidents, one with a 121.5 MHz ELT and one with a 406 MHz ELT, the NTSB concludes that switching all ELTs to 406 MHz is a necessary goal to work towards.
2610:
1999:
A Ship Security Alert System (SSAS) is a special variety of an EPIRB designed to alert the ship's owner(s) of a possible piracy or terrorist attack. They thus have several distinguishing operational differences:
1448:
COSPAS-SARSAT Council decided that future satellites would no longer carry the 121.5 MHz search and rescue repeater (SARR). Since 1 February 2009, only 406 MHz beacons are detected by the international
512:
False alarms were common, as the beacon transmitted on the aviation emergency frequency, with interference from other electronic and electrical systems. To reduce false alarms, a beacon was confirmed by a second
398:
Several systems are in use, with beacons of varying expense, different types of satellites, and varying performance. Carrying even the oldest systems provides an immense improvement in safety over carrying none.
309:
As a GEOSAR satellite remains fixed relative to the Earth rotating with the earth around the equator, GEOSAR satellites utilize the GPS provided by the EPIRB, PLB, or ELT to provide rescuers with beacon position
1755:
in a general aviation aircraft on October 16, 1972 sparked the then largest ever search and rescue effort, which proved fruitless. This high-profile event further hastened the mandating of ELTs aboard aircraft.
4818:
486:
take up to two hours because it has to use moving weather satellites to locate the beacon. To help locate the beacon, the beacon's frequency is controlled to 2 parts per billion, and its power is five watts.
217:
system for search and rescue (SAR). These beacons transmit a 406 MHz distress signal every 50 seconds, varying over a span of 2.5 seconds to avoid multiple beacons always transmitting at the same time.
2150:
VHF transmitter typically uses the same antenna as the UHF beacon, the radiated signal is further reduced by the inherent inefficiencies of transmitting with an antenna not tuned to the transmitted signal.
1199:
Federal Communications Commission. The FCC will prosecute cases based upon evidence provided by the Coast Guard, and will issue warning letters or notices of apparent liability for fines up to $ 10,000."
3247:
517:, which could easily slow confirmation of a 'case' of distress to as much as 4 hours (although in rare circumstances, the satellites could be positioned such that immediate detection becomes possible.)
2069:
The alarm signal is defined as an AM signal (A3X and/or N0N emissions), containing a swept tone ranging from 300 Hz to 1600 Hz (upwards), with 2–4 sweeps per second. PLBs shall sweep upward.
1933:
Automatic EPIRBs are water activated. Some EPIRBs also "deploy"; this means that they physically depart from their mounting bracket on the exterior of the vessel (usually by going into the water.)
4561:
3876:
1543:
3752:
5007:
2141:
1505:
301:
beacon. By monitoring the change of the beacon frequency of the received beacon signal and knowing the exact position of the satellite, the LUT is able to calculate the location of the beacon.
2586:
2500:(ICAO) regulations must register their beacons. Some national administrations (including the United States, Canada, Australia, and the UK) also require registration of 406 MHz beacons.
2061:
1457:
1613:, hard landings, movement by ground crews and aircraft maintenances, can generate false alarms, which can interfere with and cannot be distinguished from genuine emergency transmissions.
1536:
2459:(frequency band protected to ±50 kHz) (Satellite detection ceased on 1 February 2009, but this frequency is still used for short-range location during a search and rescue operation)
636:. RCCs are operated unilaterally by personnel of a single military service (e.g. an air force, or a navy) or a single civilian service (e.g. a national police force, or a coast guard).
1456:
EPIRBs that do not transmit on 406 MHz are banned on boats in the United States and in many other jurisdictions. More information about the switch to 406 MHz is available on
2120:
U.S. Military forces at one time used 121.5/243.0 MHz beacons such as the "PRC-106," which had a built-in VHF radio. The military is replacing them with modern 406 MHz PLBs.
318:
The newest of the Cospas Sarsat satellites, detect EPIRB, PLB, and ELT distress signals in almost real-time (i.e within 5 minutes) including the beacons location with or without GPS.
3390:
2493:
2507:
The U.S. Coast Guard warns that a user's "life may be saved as a result of registered emergency information" because it can respond more quickly to signals from registered beacons.
583:
signal, this registration information is passed to the rescue coordination center, which then provides the appropriate search-and-rescue agency with crucial information, such as:
3331:
4239:"RSS-287—Emergency Position Indicating Radio Beacons (EPIRB), Emergency Locator Transmitters (ELT), Personal Locator Beacons (PLB), and Maritime Survivor Locator Devices (MSLD)"
3708:"RSS-287—Emergency Position Indicating Radio Beacons (EPIRB), Emergency Locator Transmitters (ELT), Personal Locator Beacons (PLB), and Maritime Survivor Locator Devices (MSLD)"
3279:
2280:
Embedded 15-Hex ID or 15-hex transmitted distress message, for example, 2024F72524FFBFF The hex ID is printed or stamped on the outside of the beacon and is hard-coded into its
1585:
but is still found on many aircraft. ELTs are relatively large, and would fit in a cube about 30 cm (12 in) on a side, and weigh 2 to 5 kg (4.4 to 11.0 lb).
3017:
538:. If the beacon is moving toward or away from the satellite track due to the Earth's rotation, it is on one side or other of the satellite's path. Doppler shift is zero at the
4445:
2175:
beacon location data guides search and rescue efforts. No beacon is ignored. Anonymous beacons are confirmed by two Doppler tracks before beginning beacon location efforts.
903:
5003:
4801:
4529:
3721:
2526:
2510:
Unless the national registry authority advises otherwise, personal information contained in a beacon is used exclusively for SAR distress alert resolution purposes.
1941:
release unit to separate the EPIRB from its bracket. If it does not come out of the bracket it will not activate. There is a magnet in the bracket which operates a
1911:
1906:(GMDSS). Most commercial off-shore working vessels with passengers are required to carry a self-deploying EPIRB, while most in-shore and fresh-water craft are not.
392:
3933:
2287:
A location protocol number, and type of location protocol: EPIRB or MMSI, as well as all the data fields of that location protocol. If the beacon is equipped with
4709:
1404:
3836:
2550:
2518:
provides the status of 406 MHz beacon regulations in specific countries and extracts of some international regulations pertaining to 406 MHz beacons.
1476:
once again recommended that the U.S. FAA require all aircraft have 406 MHz ELTs. They first recommended this back in 2000 and after vigorous opposition by
2140:
1504:
530:
measured from the rate of change of the heard frequency, which varies both according to the path of the satellite in space and the rotation of the earth. This
3254:
2158:
406 MHz UHF beacons transmit bursts of digital information to orbiting satellites, and may also contain a low-power integrated analog (121.500 MHz)
6162:
6134:
6129:
5154:
2231:
406 MHz beacons transmit for a quarter of a second immediately when turned on, and then transmit a digital burst once every 50 seconds thereafter. Both
2060:
4181:
3194:
473:
satellites. EPIRB beacons with built-in GPS are usually called GPIRBs, for GPS position-indicating radio beacon or global position-indicating radio beacon.
4840:
549:
To increase the useful power, and handle multiple simultaneous beacons, modern 406-MHz beacons transmit in bursts, and remain silent for about 50 seconds.
4850:
5011:
4654:
4592:
4568:
3982:
3883:
3091:
2674:
1903:
1540:
1529:
1415:
877:
The U.S. NOAA operates the U.S. Mission Control Center (USMCC) in Suitland, Maryland. It distributes beacon signal reports to one or more of these RCCs:
4446:"RSS-187, Emergency Position Indicating Radio Beacons, Emergency Locator Transmitters, Personal Locator Beacons, and Maritime Survivor Locator Devices"
3934:"RSS-187, Emergency Position Indicating Radio Beacons, Emergency Locator Transmitters, Personal Locator Beacons, and Maritime Survivor Locator Devices"
3220:
2600:
1727:
that crashed on February 18, 1969 in the Sierra Nevada Mountains. Five aircraft crashed and five searchers were killed while trying to find Flight 708.
6249:
3760:
2497:
1332:
633:
4774:
4669:"Report ITU-R M.2285-0 Maritime survivor locating systems and devices (man overboard systems) -- An overview of systems and their mode of operation"
4252:
1961:
is designed to deploy automatically when submerged to a prescribed depth; the pressure of the water activates a mechanism which releases the EPIRB.
1347:
1314:
1246:
193:
6254:
4809:
3819:
3799:
3102:
2936:
2757:
Report ITU-R M.2285-0 Maritime survivor locating systems and devices (man overboard systems) -- An overview of systems and their mode of operation
2708:
1513:
Emergency Locator Transmitters (ELTs) are fairly expensive (aviation use; Average cost is $ 1500–3000) locator beacons. In commercial aircraft, a
505:
at 121.5 MHz. The frequency is often routinely monitored by commercial aircraft, but has not been monitored by satellite since Feb. 1, 2009.
3957:
3678:
4363:
1525:. In the US, ELTs are required to be permanently installed in most general aviation aircraft, depending upon the type or location of operation.
6156:
3029:
1825:
Category I – 406/121.5 MHz. Float-free, automatically activated EPIRB. Detectable by satellite anywhere in the world. Recognized by GMDSS.
1477:
604:
An unregistered 406-MHz beacon still carries some information, such as the manufacturer and serial number of the beacon, and in some cases, an
445:
2139:
1503:
6151:
6141:
6121:
5923:
4406:
4331:
4308:
3519:
2515:
1590:
210:
86:
2059:
5055:
2543:
1720:
1473:
4011:
3394:
2243:
intervals between transmission are randomly distributed on the interval 47.5 to 52.5 seconds. (specification for first-generation beacons)
2306:
When a beacon is sold to another country, the purchaser is responsible for having the beacon reprogrammed with a new country code and to
382:
The rescue authority uses its own receiving equipment afterwards to locate the beacon and commence its own rescue or recovery operations.
6234:
6146:
5992:
5051:
629:
4386:
4214:
3338:
5918:
4623:
3283:
628:
RCCs are responsible for a geographic area, known as a "search-and-rescue region of responsibility" (SRR). SRRs are designated by the
3593:
1758:
The RTCA published DO-145, DO-146, and DO-147, which the FAA then adopted the three DO documents as Technical Standard Order TSO C91.
6012:
4775:
ICAO/IMO Working Paper 10 to 14 September 2007 – Joint Working Group on Harmonization of Aeronautical and Maritime Search and Rescue
4693:
4421:
3149:
2950:
2568:
2277:
A country code, which lets the worldwide COSPAS/SARSAT central authority identify the national authority responsible for the beacon.
1840:
1261:
1215:
2462:
243.0 MHz UHF ± 12 kHz (frequency band protected to ± 100 kHz) (prior to 1 February 2009 – COSPAS-SARSAT Compatible)
367:
The transmitter is activated, either automatically in a crash or after sinking, or manually by survivors of an emergency situation.
4346:
4139:
469:
The GPS system permits stationary, wide-view geosynchronous communications satellites to enhance the Doppler position received by
6244:
5797:
5345:
5147:
3300:
3023:
2941:
These devices are commonly referred to as SEND (Satellite Emergency Notification Device), and examples include SPOT and inReach.
2924:
2869:
2802:
1793:
3781:
2010:
The COSPAS-SARSAT system sends the distress message to the vessel's country of origin, regardless of the location of the vessel.
5908:
5027:
4995:
4833:
4504:
3911:
3418:
3046:
2913:
2865:
2781:
1789:
1737:
1665:
4533:
3565:
5903:
5454:
4979:
4947:
4895:
4287:
1380:
423:
Receivers are payloads on the U.S. GPS satellites, on the Russian GLONASS satellites, and on the European GALILEO satellites.
322:
134:
The several types of emergency locator beacons are distinguished by the environment for which they were designed to be used:
1828:
Category II – 406/121.5 MHz. Similar to Category I, except is manually activated. Some models are also water activated.
1799:
180:(personal locator beacons) are carried by individuals and intended to indicate a person in distress who is away from normal
4452:
3728:
3549:
434:
Receivers are payloads on various geosynchronous satellites, including some of the U.S. GOES weather satellites (including
6264:
5928:
4796:
3108:
3040:
2902:
2311:
2307:
601:
agencies to check and eliminate false alarms (potentially sparing the beacon's owner from significant false alert fines).
245:
6213:
4765:
2303:
giving the beacon's current position. In some aircraft beacons, this data is taken from the aircraft's navigation system.
1226:) are partners in Joint Rescue Co-ordination Centres; CCG operates Maritime Rescue Subcentres to offload work from JRCC.
169:(ship security alert systems) are used to indicate possible piracy or terrorism attacks discreetly on sea-going vessels.
6203:
5964:
5861:
5404:
5171:
5039:
4987:
4983:
3034:
1741:
4606:
2492:
All distress alerting beacons operating on 406 MHz should be registered; all vessels and aircraft operating under
1850:
Class B – 121.5/243 MHz. Manually activated version of Class A. These devices have been phased out by the FCC and
928:
448:, such as USMCC (in Suitland, Maryland), where the detected location and beacon details are used to determine to which
6193:
5700:
5140:
5111:
4300:
2650:
1918:
1303:
444:
When one of the COSPAS-SARSAT satellites detects a beacon, the detection is passed to one of the program's roughly 30
376:
The ground stations process the signals and forward the data, including approximate location, to a national authority.
3840:
3642:
4422:"Handbook on Radio Frequency Spectrum Requirements for Civil Aviation including Statement of Approved ICAO Policies"
4323:
3907:
3608:
6052:
5974:
5913:
5620:
5023:
4991:
4975:
4959:
4887:
4826:
4398:
3627:
3097:
2977:
2317:
One can use the beacon decoder web page at Cospas-Sarsat to extract the 15-hex ID from the 30-hex distress message.
1994:
1574:
677:
449:
2845:
There are also other personal devices in the marketplace which do not meet the standard for 406 MHz devices.
1740:(FAA) published on March 13, 1971, Notice of Proposed Rule Making (NPRM) 71–7 with the proposed amendments to the
534:
the position of the beacon. A faster change in the Doppler indicates that the beacon is closer to the satellite's
6259:
5824:
5785:
5630:
5530:
5459:
5392:
5219:
5047:
4927:
4185:
3940:
3198:
2861:
2592:
1712:
1578:
1522:
1427:
In Vietnam, operations are supported by the Ministry of Transport, Vietnam Maritime Administration (VINAMARINE).
1355:
952:
924:
4182:"Inmarsat will withdraw epirb service in 2006 and promises new safety service on next generation I-4 satellites"
3224:
2213:
The digital distress message generated by the beacon varies according to the above factors and is encoded in 30
6183:
5425:
5360:
5313:
5199:
5121:
5095:
4374:
3011:
1982:
1593:
beacons. However, the 121.5 MHz signal is still used for close-in direction finding of a downed aircraft.
1376:
1219:
539:
69:
38:
4807:
The History and Experience of the International COSPAS-SARSAT Programme for Satellite-Aided Search and Rescue
3372:
1692:
1684:
institutes development of a "Crash-Locator Beacon" and a "Crash-Locator Bearing Recorder" in the early 1950s.
1421:
In China, operations are supported by the Maritime Safety Administration, Bureau of Harbour Superintendency.
6022:
6007:
5851:
5802:
5725:
5625:
5303:
5189:
5184:
5019:
4547:
2598:
2007:
They are prohibited from emitting a homing signal on 121.5 MHz so as to make transmissions more covert.
1702:. Later, SARBE beacons included a radio for voice communication by the survivor with the rescuing personnel.
1681:
226:
152:(emergency position-indicating radio beacons) are carried on ships and boats, and signal maritime distress.
4200:
3862:
1977:
A Submarine Emergency Positioning Indicating Radio Beacon (SEPIRB) is an EPIRB that is approved for use on
5944:
5730:
5545:
5490:
5485:
5298:
5263:
5075:
4967:
4324:"SPECIFICATION FOR SECOND-GENERATION COSPAS-SARSAT 406-MHz DISTRESS BEACONS C/S T.018 Preliminary Issue A"
2956:
2916:
channels, so they show up on ship AIS receivers. They are lightweight and can be used to equip inflatable
1744:(FAR). After public comment, the final rules were published in the Federal Register on September 21, 1971.
1514:
554:
280:
17:
4259:
5846:
5650:
5615:
5535:
5515:
5437:
5325:
5246:
5015:
4859:
4668:
4477:
4040:
3995:
3131:
3058:
2193:
1964:
609:
253:
48:
Overview diagram of COSPAS-SARSAT communication system used to detect and locate ELTs, EPIRBs, and PLBs.
4806:
1898:
Furthermore, the U.S. Coast Guard recommend that no EPIRB of any type manufactured before 1989 be used.
188:. They are also used for crew-saving applications in shipping and lifeboats at terrestrial systems. In
163:(submarine emergency position-indicating radio beacons) are EPIRBs designed only for use on submarines.
3961:
3685:
1439:
In Taiwan, operations are supported by the International Telecommunication Development Company (ITDC)
221:
When manually activated, or automatically activated upon immersion or impact, such beacons send out a
5760:
5720:
5690:
5447:
5382:
5273:
5087:
4999:
4971:
4955:
4903:
4899:
2330:
on the following key frequencies; the frequency used distinguishes the capabilities of the beacon. A
1858:
1768:
Dec 23, 1992: TSO-C126, 406 MHz Emergency Locator Transmitter (ELT) defines the 406 MHz ELT
1518:
1279:
1211:
271:
is an international organization that has been a model of international cooperation, even during the
31:
4387:
https://web.archive.org/web/20060520033357/http://www.cospas-sarsat.com/DocumentsRSeries/r9oct28.pdf
1694:- VHF, and SARBE - Search-And-Rescue-Beacon Equipment (UHF) range of beacons which were used by the
566:
beacon is about two hours. The first satellite constellation was launched in the early 1970s by the
141:(emergency locator transmitters) are carried on aircraft and are activated in the event of a crash.
5770:
5710:
5469:
5431:
5288:
5229:
5214:
4935:
4931:
4923:
4883:
3816:
2965:
2197:
1223:
613:
155:
Activated by water when the beacon is out of the bracket or manually by the ON switch on the EPIRB.
5117:
3526:
1945:
in the EPIRB. This prevents accidental activation if the unit gets wet from rain or shipped seas.
1891:, but not by the United States. In September 2004, Inmarsat announced that it was terminating its
501:
The oldest, cheapest beacons are aircraft ELTs that send an anonymous warble on the aviation band
5997:
5954:
5885:
5755:
5685:
5660:
5595:
5442:
5163:
5071:
4943:
4919:
4911:
4789:
4703:
3085:
2338:
satellite-compatible frequencies. In the past, other frequencies were also used as a part of the
2004:
They are manually activated by hidden buttons or switches, much like the alarms bank tellers use.
1411:
1272:
502:
490:
2731:
C/S T.015: Specification and Type Approval Standard for 406 MHz Ship Security Alert Beacons
2560:
1857:
Class S – 121.5/243 MHz. Similar to Class B, except it floats, or is an integral part of a
1494:
209:
Distress alerts transmitted from ELTs, EPIRBs, SSAS, and PLBs are received and processed by the
2100:
All PLBs transmit in digital mode on 406 MHz. There are AIS PLBs that transmit on VHF 70.
1647:
Within these classes, an ELT may be either a digital 406 MHz beacon, or an analog beacon (
1410:
In India, operations are supported by the Indian Space Research Organisation (ISRO) and by the
6037:
5959:
5873:
5856:
5819:
5705:
5665:
5495:
5464:
5330:
5224:
5079:
4689:
4648:
4586:
4283:
4021:. Vol. 7, no. 5. Inspector General, Department of the Air Force. May 1951. p. 4
3976:
2884:
2339:
1804:
1732:
1688:
181:
144:
Activated by G-switch (crash sensor) or manually by cockpit remote switch or ON switch on ELT.
107:
73:
4238:
3707:
2078:
PLB equipment is required to include 406 MHz plus a homing frequency on 121.5 MHz.
2026:
Personal Locator Beacons now include GPS, White and IR Strobe Lights and Return Link Service.
1395:
In Russia, operations are supported by the Federal State Unitary Enterprise Morsvyazsputnik.
1383:
operates the Mission Control Centre (UKMCC), which receives and distributes distress alerts.
452:(for example, the U.S. Coast Guard's PACAREA RCC, in Alameda, California) to pass the alert.
102:
The standard frequency of a modern EPIRB is 406 MHz. It is an internationally regulated
6239:
6042:
6002:
5982:
5949:
5878:
5836:
5750:
5605:
5590:
5565:
5540:
5500:
5350:
5209:
5204:
5194:
4963:
4221:
3301:"Civil Air Patrol, Maryland Wing Conference, Locating 121.5 & 406 MHz Emergency Beacons"
3125:
3070:
2991:
2905:), as they transmit AIS messages containing accurate GPS position information and include a
2434:
1873:
915:
4630:
2879:, or one of these: 156.525 MHz, 156.750 MHz, 156.800 MHz, 156.850 MHz,
2754:
Recommendation ITU-R M.633 (IMO's technical requirements for the 406 MHz EPIRB signal)
1436:
In Indonesia, operations are supported by the National SAR Agency of Indonesia (BASARNAS).
644:
These international search-and-rescue points of contact receive SAR alerts from the USMCC.
355:
172:
Activated by discreet switch/button in the ship's bridge or cabin, or manually on the SSAS.
5670:
5525:
5293:
5256:
5063:
4813:
4769:
4490:
4301:"SPECIFICATION FOR COSPAS-SARSAT 406 MHz DISTRESS BEACONS C/S T.001 Issue 3 – Revision 15"
3823:
3177:
3160:
ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.93, definition:
3076:
3003:
2986:
2704:
Special Committee (SC) 121 on Automatic Identification Systems (AIS) and digital Messaging
2616:
2604:
2564:
2327:
2274:
A bit telling whether the message is short (15 hex digits) or long (30 hex digits) format.
2219:
1922:
1699:
1547:
1292:
470:
225:. The signals are monitored worldwide and the location of the distress is detected by non-
222:
189:
90:
77:
5268:
4215:"Specification for COSPAS-SARSAT 406 MHz Distress Beacons C/S T.001 Issue 3 - Revision 7"
3014: – Radio-frequency beacon used to locate airplanes, vessels, and persons in distress
4347:"NASA Search and Rescue Mission Office : Distress Alerting Satellite System (DASS)"
3317:
2034:
PLBs vary in size from cigarette-packet to paperback book and weigh 200 g to 1 kg (
2022:
1660:
Any ELT that is not a 406 MHz ELT with a Hex Code became obsolete February 1, 2009.
373:
The satellites transfer the beacon's signal to their respective ground control stations.
44:
5868:
5740:
5715:
5675:
5645:
5520:
5355:
5241:
5083:
4879:
4875:
4786:"EEVblog #368 - EPIRB Teardown (Examination of the components of a 121/5/243Mhz Epirb)"
4350:
4143:
3114:
2359:
1602:
1558:
1286:
526:
514:
489:
Both of the above types of beacons usually include an auxiliary 25-milliwatt beacon at
230:
103:
2812:
1895:
EPIRB service as of December 2006 due to a lack of interest in the maritime community.
6228:
6017:
5790:
5780:
5695:
5585:
5580:
5570:
5555:
5377:
5236:
5059:
5035:
4891:
4855:
3785:
3505:
3026: – 1996 business jet disappearance near Dorchester, New Hampshire, United States
2854:
2521:
The following list shows the agencies accepting 406 beacon registrations by country:
2477:
2335:
2159:
1862:
1695:
1691:, and at the same time Burndept produced the TALBE (Talk and Listen Beacon Equipment)
1449:
1430:
In Singapore, operations are supported by the Civil Aviation Authority of Singapore.
268:
234:
4508:
4282:
Albert Helfrick, Principles of Avionics, 5th Edition, Avionics Communications, 2009
3425:
3419:"USMCC 406 MHz Alert and Support Messages for the LEOSAR/GEOSAR/MEOSAR (LGM) System"
2740:
C/S G.005, Guidelines on 406 MHz Beacon Coding, Registration, and Type Approval
1816:
Emergency position-indicating radio beacons (EPIRBs) are sub-classified as follows:
5895:
5735:
5680:
5610:
5575:
5510:
5409:
5399:
5251:
5043:
4951:
4939:
4915:
4907:
2633:
Several regulations and technical specifications govern emergency locator beacons:
2178:
The distress message transmitted by a 406 beacon contains the information such as:
1724:
1299:
567:
95:
1324:
AIRCOM also operates the Canadian Mission Control Centre (CMCC) from JRCC Trenton
27:
Distress radio beacon, a tracking transmitter that is triggered during an accident
4164:
4082:
2857:
locator beacon. In the U.S., rules were established in 2016 in 47 C.F.R. Part 95
1687:
In the UK, by 1959 the first automatic beacon for liferafts had been produced by
939:
On-shore beacons are investigated by local search-and-rescue services in Alaska.
6095:
5745:
5655:
5640:
5600:
5560:
5419:
5091:
4399:"COSPAS-SARSAT 406 MHz FREQUENCYMANAGEMENT PLAN C/S T.012 Issue 1 – Revision 10"
3468:
2536:
2481:
2214:
1942:
1938:
1803:
A GPS-enabled EPIRB transmitter alerts agencies of an emergency, assisting with
1752:
1486:
has conducted crash tests with small airplanes to investigate how ELTs perform.
590:
a description of the vessel, aircraft, vehicle, or person (in the case of a PLB)
531:
4686:
Life-saving appliances: including LSA code/ International Maritime Organization
2722:
C/S A.002: Cospas-Sarsat Mission Control Centres Standard Interface Description
2188:
The encoded identification of the vessel or aircraft in distress, either as an
6100:
5807:
5505:
5414:
5370:
5340:
5318:
5308:
5283:
5067:
4785:
4779:
3621:
2441:
1884:
1748:
1621:
Emergency locator transmitters (ELTs) for aircraft may be classed as follows:
1610:
1207:
The Canadian Mission Control Centre receives and distributes distress alerts.
4762:
3817:
Regulations Amending the Canadian Aviation Regulations (Parts I and VI – ELT)
2728:
C/S T.007: COSPAS‑SARSAT 406 MHz Distress Beacons Type Approval Standard
1433:
In the Republic of Korea, operations are supported by the Korea Coast Guard.
6085:
5550:
5365:
2437:
channels 15/16 – these channels are used only on the obsolete Class C EPIRBs
2300:
2107:. PLBs should not be used in cases where normal emergency response (such as
1978:
1403:
In Hong Kong, operations are supported by the Hong Kong Marine Department's
214:
111:
82:
1915:
3649:
3579:"NTSB to FAA: Require 406 MHz ELTs | Doug Ritter's Equipped.org Blog"
2968:. It would have to be seen by an amateur radio operator and forwarded on.
2270:
Example hex codes look like the following: 90127B92922BC022FF103504422535
203:
Activated manually by deploying antenna and pressing the ON button/switch.
6080:
6070:
5987:
5812:
5635:
3052:
2917:
2896:
2445:
2310:
it with their nation's beacon registry, and the seller is responsible to
2296:
2281:
2185:
A unique 15-digit hexadecimal beacon identification code (a "15-hex ID").
272:
249:
115:
4748:
Cospas-Sarsat – the International Satellite System For Search and Rescue
3594:"Second Crash Test Harvests Valuable Data to Improve Emergency Response"
2959:
to track positions and send short messages. Most APRS packets contain a
1180:
U.S. Coast Guard Sector Guam (RSC) (coordinates SAR under RCC Honolulu)
6075:
6060:
2725:
C/S T.001 Specification for COSPAS-SARSAT 406 MHz Distress Beacons
2623:
Cospas-Sarsat International 406 MHz Beacon Registration Database (IBRD)
2292:
2209:
Whether or not the beacon contains a 121.5 MHz homing transmitter.
2171:
1708:
Mar 17 1969: FAA Advisory Circular 91-19 advised pilots to install ELTs
1606:
1577:(ADF) radionavigation equipment, which is being phased out in favor of
1562:
435:
260:
do not operate on 406 MHz, thus are covered in separate articles.
3088: – Electronic rescue and locating system for use by divers at sea
2640:
AC 20–85, Emergency Locator Transmitters and Receivers, March 16, 1973
2075:
They must be registered to a specific person (with NOAA in the U.S.).
1765:
March 16, 1973: AC 20–85, Emergency Locator Transmitters and Receivers
6105:
6065:
5387:
5179:
5132:
3578:
2887:
equipment mounted on the vessel on which the survivor was traveling.
2251:
2236:
2232:
2163:
2145:
The radiotelephony locator beacon sound made by ELTs and some EPIRBs.
2065:
The radiotelephony locator beacon sound made by PLBs and some EPIRBs.
1509:
The radiotelephony locator beacon sound made by ELTs and some EPIRBs.
306:
GEOSAR or Geosynchronous Earth Orbiting Search and Rescue Satellites
4797:
Rescue Coordination Centres (RCCs) and SAR Points of Contact (SPOCs)
4607:"C/S T.001 Specification for COSPAS-SARSAT 406 MHz Distress Beacons"
2901:
These devices are distinct from traditional SAR radar transponders (
2580:
2014:
As with EPIRBs, the RTCM maintains specifications for SSAS devices.
52:
4763:
NOAA notice of planned phasing out of 121.5/243 MHz beacons in 2009
4752:
4054:
3079: – Radio transmitter to identify a location for navigation aid
363:
A transmission is typically detected and processed in this manner:
275:. SARSAT means search-and-rescue satellite-aided tracking. COSPAS (
72:
for commercial and recreational boats, a portable, battery-powered
6090:
6027:
5335:
5031:
4729:
3120:
3064:
2622:
2250:
406 MHz beacons will be the only beacons compatible with the
2137:
2108:
2057:
2021:
1963:
1888:
1798:
1501:
1493:
535:
391:
has a network of direction finder sites along the coastlines. The
354:
257:
197:
185:
51:
43:
3117: – Small radios carried to facilitate rescue in an emergency
3094: – Worldwide emergency communication system for ships at sea
3049: – Automatic tracking system that uses transceivers on ships
2698:
Special Committee (SC) 110 on Emergency Beacons (EPIRBs and PLBs)
321:
The new MEOSAR system also provides the framework along with the
6032:
4747:
4428:
2693:
2574:
2189:
1782:
1483:
605:
388:
5136:
4822:
2701:
Special Committee (SC) 119 on Maritime Survivor Locator Devices
2222:, which ensures a net zero phase shift aiding Doppler location
1528:
The specifications for the design of ELTs are published by the
395:
maintains a near-real-time map that shows SARSAT U.S. Rescues.
5278:
4757:
2960:
2910:
2906:
2532:
2456:
2452:
2355:
2288:
2167:
1582:
1557:
ELTs are unique among distress radiobeacons in that they have
379:
The national authority forwards the data to a rescue authority
238:
2314:
the deprecated beacon ID with their national beacon registry.
1869:. Their use is no longer recommended by the U.S. Coast Guard.
1472:
In a Safety Recommendation released September 2007, the U.S.
596:
any additional information that may be useful to SAR agencies
1424:
In Japan, operations are supported by the Japan Coast Guard
412:
Receivers are payloads on various Low Earth Orbit satellites
85:
operated by an international consortium of rescue services,
5008:
Satellite emergency position-indicating radiobeacon station
2669:
TSO-C126b: 406 MHz Emergency Locator Transmitter (ELT)
2666:
TSO-C126a: 406 MHz Emergency Locator Transmitter (ELT)
2192:
value, or as, in the case of an ELT, either the aircraft's
2103:
Personal locator beacons operating on 406 MHz must be
664:
Argentina - Servicio de Alerta de Socorro Satelital (SASS)
409:
Support Doppler detection and reception of encoded position
4055:"Family gets answers about mysterious plane crash in 1969"
2663:
TSO-C126: 406 MHz Emergency Locator Transmitter (ELT)
1677:
Automatic SOS radios were developed as early as the 1930s.
691:
Central American Corporation for Navigation Area Services
370:
At least one satellite picks up the beacon's transmission.
315:
MEOSAR or Mid-Earth Orbiting Search and Rescue Satellites
297:
LEOSAR or Low Earth Orbiting Search and Rescue Satellites
4120:, Volume 36, Number 50, March 13, 1971, pages 4,878-4,881
3877:"TSO-C91a, Emergency Locator Transmitter (ELT) Equipment"
3863:"COPA Flight 8 Ottawa: July 2009 Update on 4006 MHz ELTs"
3568:. National Transportation Safety Board. 4 September 2007.
3105: – Portable emergency satellite communication device
3073: – Civilian auxiliary of the United States Air Force
1705:
Jan 9 1964: FAA Advisory Circular 170-4 investigated ELTs
4753:
ITU – Maritime mobile Access and Retrieval System (MARS)
4083:"Civil Aviation Bills Facing Uncertain Fate in Congress"
2424:
Ch-19 S: 406.076 MHz (operational at a future date)
2421:
Ch-18 R: 406.073 MHz (operational at a future date)
2412:
Ch-15 O: 406.064 MHz (operational at a future date)
2409:
Ch-14 N: 406.061 MHz (operational at a future date)
2400:
Ch-11 K: 406.052 MHz (operational at a future date)
2397:
Ch-10 J: 406.049 MHz (operational at a future date)
4165:"TSO-C126, 406 MHz Emergency Locator Transmitter (ELT)"
4108:
Cong. Rec., Vol. 116, May 12, 1970, pages 15,134-15,136
3373:"Aircraft beacon has become utterly outmoded, FAA says"
3081:
Pages displaying short descriptions of redirect targets
3055: – Radio transmitter which sends a location signal
2346:
Cospas-Sarsat (satellite) compatible beacon frequencies
1973:
Submarine Emergency Positioning Indicating Radio Beacon
3643:"Comparison of 406 MHz and 121.5 MHz Distress Beacons"
3150:
Community Emergency Response Team Participant Handbook
3020: – 1986 aviation disaster in the Shetland Islands
2494:
International Convention for the Safety of Life at Sea
2089:
There are two kinds of personal locator beacon (PLB):
3450:"U.S. Coast Guard Rescue Coordination Centers (RCCs)"
3111: – Transponder intended for emergency use at sea
3043: – Transponder intended for emergency use at sea
2975:
2597:
New Zealand - New Zealand Rescue Coordination Centre
2557:
2093:
PLB with GPS data (internally or externally provided)
1981:. Two are carried on board and can be fired from the
4070:, Volume 116, December 30, 1970, pages 44,064-44,065
3018:
1986 British International Helicopters Chinook crash
2504:
There is no charge to register 406 MHz beacons.
1865:. These devices have been phased out by the FCC and
911:
Land-based emergency signals in the lower 48 states
81:
emergency and render aid. The signal is detected by
6114:
6051:
5973:
5937:
5894:
5835:
5769:
5478:
5170:
4866:
3908:"Section 2. Emergency Services Available to Pilots"
3469:"Emergency Position Indicating Radiobeacon (EPIRB)"
3332:"MEOSAR: Medium Earth Orbiting Search & Rescue"
2734:
C/S G.003, Introduction to the Cospas-Sarsat System
2646:
AC 91-19 mar 17 1969 advised pilots to install ELTs
2334:beacon can operate on one of the three (currently)
2072:PLB alerts are passed to State and Local agencies.
955:investigates offshore beacons and rescues victims.
4129:FR 36-183, September 21, 1971, pages 18,716-18,725
4081:
1551:
5004:Emergency position-indicating radiobeacon station
4440:
4438:
4220:. cospas-sarsat.com. May 20, 2006. Archived from
3463:
3461:
3459:
3162:emergency position-indicating radiobeacon station
1443:Phase-out of 121.5 MHz satellite alerting service
4737:RTCM, Standard for 406 MHz Satellite EPIRBs
2694:Radio Technical Commission for Maritime Services
2609:Switzerland - Federal Office for Civil Aviation
56:First generation EPIRB emergency locator beacons
2853:A Maritime Survivor Locator Device (MSLD) is a
2719:C/S A.001: Cospas-Sarsat Data Distribution Plan
2527:National Oceanic and Atmospheric Administration
393:National Oceanic and Atmospheric Administration
4725:COSPAS-SARSAT, Document C/S T.001 October 1999
2226:406 MHz beacon facts and transmission schedule
1464:global VHF aircraft voice distress frequency.
1405:Hong Kong Maritime Rescue Co-ordination Centre
525:The Cospas-Sarsat system was made possible by
5148:
4834:
4253:"2017 FCC Marine Communications Rule Changes"
4201:"Notice 34 Information Concerning Submarines"
3061: – Emergency locator rescue radio beacon
2776:EPIRB hydrostatic release device requirements
2581:Stazione Satellitare Italiana - Cospas Sarsat
2551:United Kingdom Maritime and Coastguard Agency
8:
4548:"CFR §91.207 Emergency locator transmitters"
2931:SEND—Satellite Emergency Notification Device
2539:for civil beacons, CMCC for military beacons
2516:Cospas-Sarsat Handbook of Beacon Regulations
2429:Cospas-Sarsat unsupported beacon frequencies
2362:at 406.025-406.076 MHz ± 0.005 MHz
2081:As of 2017, PLBs must have an internal GPS.
1877:devices have been phased out by the FCC and
402:The types of satellites in the network are:
387:121.500 MHz whenever possible, and the
6163:Global telecommunications regulation bodies
4090:. Vol. 95, no. 12. pp. 54–55
431:Supports only reception of encoded position
293:The satellites used in the system include:
99:beacons location as they arrived on scene.
6199:
5155:
5141:
5133:
5012:Standard frequency and time signal station
4841:
4827:
4819:
4708:: CS1 maint: location missing publisher (
3092:Global Maritime Distress and Safety System
2675:Radio Technical Commission for Aeronautics
1904:Global Maritime Distress and Safety System
1773:Emergency Position-Indicating Radio Beacon
1498:ELT about to be installed onto an airplane
1416:Maritime Rescue Coordination Centre Mumbai
1122:(RCC Honolulu; operated as JRCC with DOD)
30:"PLB" redirects here. For other uses, see
18:Emergency Position-Indicating Radio Beacon
4080:Winston, Donald C. (September 20, 1971).
3520:"Report to the Maritime Safety Committee"
3280:"What happens when I activate my beacon?"
3248:"Inquest into the death of David Iredale"
2743:C/S S.007, Handbook of Beacon Regulations
2498:International Civil Aviation Organization
2257:406 MHz beacons must be registered (
2182:Which country the beacon originates from.
1333:Joint Rescue Coordination Centre Victoria
634:International Civil Aviation Organization
194:NSW National Parks & Wildlife Service
62:emergency position-indicating radiobeacon
3128: – 1989 aviation accident in Brazil
3037: – Emergency aeronautical frequency
1315:Joint Rescue Coordination Centre Trenton
1247:Joint Rescue Coordination Centre Halifax
1228:
879:
646:
570:, Canada, France and the United States.
37:For broader coverage of this topic, see
4780:Operation of a Hydrostatic Release Unit
4140:"Emergency Locator Transmitters (ELTs)"
3142:
3103:Satellite emergency notification device
2982:
2937:Satellite emergency notification device
2709:Satellite Emergency Notification Device
2654:§91.207 Emergency locator transmitters.
2388:Ch-7 G: 406.040 MHz (in use today)
2385:Ch-6 F: 406.037 MHz (in use today)
2376:Ch-3 C: 406.028 MHz (in use today)
2373:Ch-2 B: 406.025 MHz (in use today)
2162:. They can be uniquely identified (via
1278:the northern and western waters of the
1160:U.S. Coast Guard Sector San Juan (RSC)
420:Medium Earth Orbiting Search and Rescue
4701:
4653:: CS1 maint: archived copy as title (
4646:
4591:: CS1 maint: archived copy as title (
4584:
4486:
4475:
3981:: CS1 maint: archived copy as title (
3974:
3702:
3700:
3698:
3673:
3671:
3669:
3361:See COSPAS-SARSAT document A.001, 2005
3030:Acronyms and abbreviations in avionics
1747:The disappearance of U.S. Congressmen
4407:International Cospas-Sarsat Programme
4332:International Cospas-Sarsat Programme
4309:International Cospas-Sarsat Programme
4041:"Flight magazine, 18 September, 1959"
3753:"Historical Technical Standard Order"
3637:
3635:
3500:
3498:
3496:
3494:
3492:
3490:
3488:
3486:
3484:
3482:
3413:
3411:
3295:
3293:
2643:AC 170-4 Jan 9 1964 investigated ELTs
2467:License and registration requirements
1348:Maritime Rescue Sub-Centre St. John's
1285:the navigable estuary portion of the
593:the home port of a vessel or aircraft
264:International COSPAS-SARSAT Programme
237:, and in more recent EPIRBs, also by
211:International Cospas-Sarsat Programme
7:
6209:
3371:Friess, Steve (September 11, 2007).
3171:
3169:
2544:Australian Maritime Safety Authority
2370:Ch-1 A: 406.022 MHz (reference)
1721:Hawthorne Nevada Airlines Flight 708
1474:National Transportation Safety Board
904:Air Force Rescue Coordination Center
196:provide personal locator beacons to
4854:
2823:Submergence and manual release test
2351:see above for transmission schedule
1968:EPIRB hydrostatic release mechanism
1733:Senator Peter Dominick (R-Colorado)
1648:
1458:Cospas-Sarsat's 121.5/243 Phase-Out
1354:waters surrounding the province of
630:International Maritime Organization
333:that can initiate a rescue effort.
244:Loosely related devices, including
4088:Aviation Week and Space Technology
3550:Use of 121.5/243 MHz EPIRBs Banned
2881:161.975 MHz, 162.025 MHz
2803:CFR title 46 Vol 6 Section 160.062
1953:Automatic hydrostatic release unit
1340:Victoria Search and Rescue Region
1322:Trenton Search and Rescue Region.
914:United States Air Force Auxiliary
542:between the beacon and the orbit.
336:Cospas Sarsat Monitoring include:
130:Types of emergency locator beacons
25:
2951:Automatic Packet Reporting System
2737:C/S G.004, Cospas-Sarsat Glossary
2569:Hellenic Civil Aviation Authority
2258:
2239:satellites monitor these signals.
2104:
1841:Federal Communications Commission
1550:(of the type described below as "
1262:Maritime Rescue Sub-Centre Quebec
1254:Halifax Search and Rescue Region
1216:Canadian Forces Search and Rescue
929:Alaska Rescue Coordination Center
521:Location by Doppler (without GPS)
104:mobile radiocommunication service
6250:International telecommunications
6208:
6198:
6189:
6188:
6177:
5798:Free-space optical communication
5116:
5107:
5106:
4849:
4792:from the original on 2021-12-11.
4532:. March 25, 2013. Archived from
4364:Example of 406 MHz Beacon Coding
3800:"Emergency Locator Transmitters"
3609:"NASA Completes ELT Crash Tests"
3024:1996 New Hampshire Learjet crash
2997:
2985:
2927:numbers in the range 970YYxxxx.
2872:numbers in the range 972yyzzzz.
2849:Maritime Survivor Locator Device
2448:satellites on 1646 MHz UHF.
2134:Analog 121.500 MHz homing signal
1796:numbers in the range 974yyzzzz.
346:Rescue Coordination Center (RCC)
110:operations to detect and locate
5048:Instrument landing system (ILS)
4996:Radio direction-finding station
4858:and systems in accordance with
3912:Federal Aviation Administration
3784:. July 19, 2011. Archived from
3592:McDonald, Samuel (2015-07-29).
3566:Safety recommendation (A-07-51)
3246:Milovanovich, C. (7 May 2009).
3178:"Cospas-Sarsat System Overview"
3047:Automatic identification system
2923:AIS-SART devices are allocated
2829:Technical tests on the membrane
2782:Safety of Life a Sea Convention
1738:Federal Aviation Administration
1719:The winter 1969 search for the
1666:Federal Aviation Administration
1609:. Numerous activities, such as
192:, some police stations and the
6255:Radio stations and systems ITU
4980:Radionavigation mobile station
4948:On-board communication station
4896:High altitude platform station
4688:(2nd ed.). London. 2010.
2909:receiver and a transmitter on
2707:Special Committee (SC) 128 on
2206:When equipped, a GPS position.
1902:EPIRBs are a component of the
1490:Emergency Locator Transmitters
1381:Maritime and Coastguard Agency
288:Sistema Poiska Avariynyh Sudov
246:search and rescue transponders
1:
4199:Canadian Coast Guard (2017).
3109:Search and rescue transponder
3041:Search and rescue transponder
2809:U.S. Coast Guard Regulations
2200:(from its Mode-S transponder)
2166:). Advanced beacons encode a
1552:Traditional ELT, unregistered
1295:within the province of Quebec
1282:within the province of Quebec
1275:within the province of Quebec
497:Traditional ELT, unregistered
343:Mission Control Centers (MCC)
6184:Telecommunication portal
5965:Telecommunications equipment
5028:Ship's emergency transmitter
4988:Radiolocation mobile station
4984:Radionavigation land station
4530:"Agentschap Telecom - EPIRB"
3861:Hunt, Adam (July 27, 2009).
3035:Aircraft emergency frequency
2154:Digital 406 MHz beacons
1742:Federal Aviation Regulations
1298:the southern portion of the
1037:District 8: New Orleans, LA
5701:Alexander Stepanovich Popov
4788:. YouTube. 9 October 2012.
3837:"Canada Backs Off 406 ELTs"
3607:Kauh, Elaine (2015-08-26).
2651:Code of Federal Regulations
2558:Ministry of Merchant Marine
2366:Channel frequency (status)
1672:Timeline of ELT development
1304:Carillon Generating Station
997:District 5: Portsmouth, VA
359:VHF radio direction finding
340:Local User Terminals (LUTs)
6281:
6235:Aircraft emergency systems
5405:Telecommunications history
5024:Experimental radio station
4992:Radiolocation land station
4976:Radiodetermination station
4960:Aeronautical earth station
3679:"EBC-502HM Specifications"
3098:Index of aviation articles
2948:
2934:
2894:
2326:Distress beacons transmit
1995:Ship Security Alert System
1992:
1989:Ship Security Alert System
1792:transmitter are allocated
1575:Automatic Direction Finder
1539:, ELTs built according to
1162:(sub-sector of RCC Miami)
1120:District 14: Honolulu, HI
1057:District 9: Cleveland, OH
962:Coast Guard Atlantic Area
763:Mexico Telecommunications
678:Maritime Operations Centre
578:Search-and-rescue response
493:to guide rescue aircraft.
450:rescue coordination centre
36:
29:
6172:
6013:Public Switched Telephone
5825:telecommunication circuit
5786:Fiber-optic communication
5531:Francis Blake (telephone)
5326:Optical telecommunication
5102:
4928:Land mobile earth station
3253:. Lawlink. Archived from
3067: – Rescue technology
2817:Corrosion resistance test
2799:U.S. Federal Regulations
2593:Danish Maritime Authority
2418:Ch-17 Q: 406.070 MHz
2415:Ch-16 P: 406.067 MHz
2406:Ch-13 M: 406.058 MHz
2403:Ch-12 L: 406.055 MHz
1983:submerged signal ejectors
1916:on the 121.5/243 phaseout
1859:survival craft (lifeboat)
1523:underwater locator beacon
1356:Newfoundland and Labrador
1100:District 13: Seattle, WA
1082:Pacific SAR Coordinator)
1077:District 11: Alameda, CA
950:
925:Alaska Air National Guard
540:closest point of approach
481:High-precision registered
5924:Orbital angular-momentum
5361:Satellite communications
5200:Communications satellite
5096:Emergency locator beacon
4431:. 2009. Doc 9718-AN/957.
3012:Emergency locator beacon
2841:Alternative technologies
2533:Canadian Beacon Registry
2394:Ch-9 I: 406.046 MHz
2391:Ch-8 H: 406.043 MHz
2382:Ch-5 E: 406.034 MHz
2379:Ch-4 D: 406.031 MHz
2130:monitored by satellite.
1959:hydrostatic release unit
1879:are no longer recognized
1867:are no longer recognized
1852:are no longer recognized
1845:are no longer recognized
1812:EPIRB sub-classification
1628:AD: automatic deployable
1625:A: automatically ejected
1453:receivers and aircraft.
1377:Department for Transport
1375:The United Kingdom, the
1220:Royal Canadian Air Force
1140:District 17: Juneau, AK
227:geostationary satellites
70:emergency locator beacon
39:Emergency locator beacon
6245:Emergency communication
5803:Molecular communication
5626:Gardiner Greene Hubbard
5455:Undersea telegraph line
5190:Cable protection system
5020:Radio astronomy station
3996:"Another Automatic SOS"
3722:"C-S Emergency Beacons"
3391:"SAR Points of Contact"
2957:amateur radio operators
2875:A MSLD may transmit on
2587:Agentschap Telecom (NL)
2444:beacons transmitted to
2018:Personal Locator Beacon
1682:United States Air Force
977:District 1: Boston, MA
446:Mission Control Centers
283:for the Russian words "
76:used in emergencies to
5945:Communication protocol
5731:Charles Sumner Tainter
5546:Walter Houser Brattain
5491:Edwin Howard Armstrong
5299:Information revolution
4968:Aircraft earth station
4888:Survival craft station
4375:beacon decoder webpage
4001:15 September 1938 p241
2146:
2085:PLB sub-classification
2066:
2027:
1969:
1820:Recognized categories:
1808:
1664:According to the U.S.
1637:AP: automatic portable
1617:ELT sub-classification
1515:cockpit voice recorder
1510:
1499:
1017:District 7: Miami, FL
555:fast Fourier transform
360:
351:Detection and location
254:avalanche transceivers
57:
49:
5919:Polarization-division
5651:Narinder Singh Kapany
5616:Erna Schneider Hoover
5536:Jagadish Chandra Bose
5516:Alexander Graham Bell
5247:online video platform
4860:ITU Radio Regulations
3318:"SARSAT U.S. Rescues"
3286:on February 19, 2014.
3132:GPS aircraft tracking
3059:Avalanche transceiver
2144:
2064:
2025:
1967:
1802:
1713:Saturday Evening Post
1561:and are activated by
1508:
1497:
1468:FAA transition status
936:Alaskan inland areas
775:Netherlands Antilles
587:phone numbers to call
461:GPS-based, registered
358:
55:
47:
6265:Radio geopositioning
5761:Vladimir K. Zworykin
5721:Almon Brown Strowger
5691:Charles Grafton Page
5346:Prepaid mobile phone
5274:Electrical telegraph
5088:Multi-satellite link
5044:Radar beacon (racon)
5000:Radio beacon station
4972:Broadcasting station
4956:Aeronautical station
4904:Mobile earth station
4188:on December 9, 2006.
4068:Congressional Record
3227:on 15 September 2012
2966:emergency responders
2295:, a rough (rounded)
2096:PLB with no GPS data
1723:"Gamblers' Special"
1601:Automatic ELTs have
1519:flight data recorder
1302:downstream from the
1280:Gulf of St. Lawrence
1238:Geographic Coverage
1212:Canadian Coast Guard
892:Geographic coverage
881:United States SPOCs
799:Trinidad and Tobago
656:Geographic Coverage
624:Responsible agencies
213:, the international
32:PLB (disambiguation)
5711:Johann Philipp Reis
5470:Wireless revolution
5432:The Telephone Cases
5289:Hydraulic telegraph
4936:Coast earth station
4924:Land mobile station
4876:Terrestrial station
4758:NOAA SARSAT website
3946:on August 11, 2011.
3473:www.navcen.uscg.gov
2220:Manchester encoding
2198:ICAO 24-bit address
1634:AF: automatic fixed
1589:their 406 MHz
1224:Royal Canadian Navy
882:
715:Dominican Republic
614:ICAO 24-bit address
5909:Frequency-division
5886:Telephone exchange
5756:Charles Wheatstone
5686:Jun-ichi Nishizawa
5661:Innocenzo Manzetti
5596:Reginald Fessenden
5331:Optical telegraphy
5164:Telecommunications
4944:Ship earth station
4920:Base earth station
4912:Land earth station
4812:2017-01-21 at the
4768:2021-05-22 at the
4536:on March 25, 2013.
4427:(Fifth ed.).
3822:2015-03-25 at the
3757:www.airweb.faa.gov
3377:The New York Times
3176:O'Connors, Chris.
3086:ENOS Rescue-System
2615:2018-07-12 at the
2603:2016-12-02 at the
2563:2003-08-06 at the
2147:
2067:
2028:
1970:
1943:reed safety switch
1921:2018-02-09 at the
1809:
1640:W: water activated
1546:2008-07-04 at the
1511:
1500:
1412:Indian Coast Guard
1273:St. Lawrence River
1039:(RCC New Orleans)
880:
503:distress frequency
361:
182:emergency services
58:
50:
6222:
6221:
5960:Store and forward
5955:Data transmission
5869:Network switching
5820:Transmission line
5666:Guglielmo Marconi
5631:Internet pioneers
5496:Mohamed M. Atalla
5465:Whistled language
5130:
5129:
5080:Satellite network
4728:FCC, Part 80 and
4485:Missing or empty
4472:: 10. March 2009.
4353:on March 4, 2016.
3914:. p. 6-2-4.c
3788:on July 19, 2011.
2885:Direction finding
2860:MOB devices with
2820:Temperature tests
2549:United Kingdom –
2340:search and rescue
2142:
2062:
2031:for PLB devices.
1949:and Activation."
1833:Obsolete classes:
1689:Ultra Electronics
1537:14 CFR 91.207.a.1
1506:
1363:
1362:
1196:
1195:
1079:(RCC Alameda and
946:U.S. Coast Guard
870:
869:
108:search-and-rescue
74:radio transmitter
16:(Redirected from
6272:
6260:Rescue equipment
6212:
6211:
6202:
6201:
6192:
6191:
6182:
6181:
6180:
6053:Notable networks
6043:Wireless network
5983:Cellular network
5975:Types of network
5950:Computer network
5837:Network topology
5751:Thomas A. Watson
5606:Oliver Heaviside
5591:Philo Farnsworth
5566:Daniel Davis Jr.
5541:Charles Bourseul
5501:John Logie Baird
5210:Data compression
5205:Computer network
5157:
5150:
5143:
5134:
5120:
5110:
5109:
5076:Satellite system
4964:Aircraft station
4871:
4853:
4843:
4836:
4829:
4820:
4793:
4714:
4713:
4707:
4699:
4682:
4676:
4675:
4673:
4665:
4659:
4658:
4652:
4644:
4642:
4641:
4635:
4629:. Archived from
4628:
4620:
4614:
4613:
4611:
4603:
4597:
4596:
4590:
4582:
4580:
4579:
4573:
4567:. Archived from
4566:
4558:
4552:
4551:
4544:
4538:
4537:
4526:
4520:
4519:
4517:
4516:
4507:. Archived from
4501:
4495:
4494:
4488:
4483:
4481:
4473:
4466:
4460:
4459:
4458:on July 6, 2011.
4457:
4451:. Archived from
4450:
4442:
4433:
4432:
4426:
4418:
4412:
4411:
4403:
4395:
4389:
4384:
4378:
4372:
4366:
4361:
4355:
4354:
4349:. Archived from
4343:
4337:
4336:
4328:
4320:
4314:
4313:
4305:
4297:
4291:
4280:
4274:
4273:
4271:
4270:
4264:
4258:. Archived from
4257:
4249:
4243:
4242:
4235:
4229:
4228:
4227:on May 20, 2006.
4226:
4219:
4211:
4205:
4204:
4196:
4190:
4189:
4184:. Archived from
4178:
4172:
4171:
4169:
4161:
4155:
4154:
4152:
4151:
4142:. Archived from
4136:
4130:
4127:
4121:
4118:Federal Register
4115:
4109:
4106:
4100:
4099:
4097:
4095:
4085:
4077:
4071:
4065:
4059:
4058:
4051:
4045:
4044:
4037:
4031:
4030:
4028:
4026:
4016:
4008:
4002:
3993:
3987:
3986:
3980:
3972:
3970:
3969:
3960:. Archived from
3954:
3948:
3947:
3945:
3939:. Archived from
3938:
3930:
3924:
3923:
3921:
3919:
3904:
3898:
3897:
3895:
3894:
3888:
3882:. Archived from
3881:
3873:
3867:
3866:
3858:
3852:
3851:
3849:
3848:
3839:. Archived from
3833:
3827:
3814:
3808:
3807:
3796:
3790:
3789:
3778:
3772:
3771:
3769:
3768:
3759:. Archived from
3749:
3743:
3742:
3740:
3739:
3733:
3727:. Archived from
3726:
3718:
3712:
3711:
3704:
3693:
3692:
3690:
3684:. Archived from
3683:
3675:
3664:
3663:
3661:
3660:
3654:
3648:. Archived from
3647:
3639:
3630:
3624:
3623:NASA crash video
3619:
3613:
3612:
3604:
3598:
3597:
3589:
3583:
3582:
3575:
3569:
3563:
3557:
3547:
3541:
3540:
3538:
3537:
3531:
3525:. Archived from
3524:
3516:
3510:
3509:
3502:
3477:
3476:
3465:
3454:
3453:
3446:
3440:
3439:
3437:
3436:
3430:
3424:. Archived from
3423:
3415:
3406:
3405:
3403:
3402:
3393:. Archived from
3387:
3381:
3380:
3368:
3362:
3359:
3353:
3352:
3350:
3349:
3343:
3337:. Archived from
3336:
3328:
3322:
3321:
3314:
3308:
3307:
3305:
3297:
3288:
3287:
3282:. Archived from
3276:
3270:
3269:
3267:
3265:
3260:on 22 March 2011
3259:
3252:
3243:
3237:
3236:
3234:
3232:
3223:. Archived from
3221:"Rescue Stories"
3217:
3211:
3210:
3208:
3206:
3197:. Archived from
3195:"SAR statistics"
3191:
3185:
3184:
3182:
3173:
3164:
3158:
3152:
3147:
3126:Varig Flight 254
3082:
3071:Civil Air Patrol
3002:
3001:
3000:
2990:
2989:
2981:
2955:APRS is used by
2877:121.500 MHz
2832:Performance test
2621:International –
2525:United States –
2435:Marine VHF radio
2328:distress signals
2143:
2063:
2053:
2052:
2048:
2043:
2042:
2038:
1929:EPIRB activation
1521:must contain an
1507:
1229:
1059:(RCC Cleveland)
916:Civil Air Patrol
883:
647:
456:Beacon operation
21:
6280:
6279:
6275:
6274:
6273:
6271:
6270:
6269:
6225:
6224:
6223:
6218:
6178:
6176:
6168:
6110:
6047:
5969:
5933:
5890:
5839:
5831:
5772:
5765:
5671:Robert Metcalfe
5526:Tim Berners-Lee
5474:
5294:Information Age
5166:
5161:
5131:
5126:
5098:
5064:Radio altimeter
5040:Secondary radar
5016:Amateur station
4869:
4867:
4862:
4847:
4814:Wayback Machine
4784:
4770:Wayback Machine
4744:
4722:
4717:
4700:
4696:
4684:
4683:
4679:
4671:
4667:
4666:
4662:
4645:
4639:
4637:
4633:
4626:
4624:"Archived copy"
4622:
4621:
4617:
4609:
4605:
4604:
4600:
4583:
4577:
4575:
4571:
4564:
4562:"Archived copy"
4560:
4559:
4555:
4546:
4545:
4541:
4528:
4527:
4523:
4514:
4512:
4505:"KANNAD 406 AS"
4503:
4502:
4498:
4484:
4474:
4468:
4467:
4463:
4455:
4448:
4444:
4443:
4436:
4424:
4420:
4419:
4415:
4410:. October 2014.
4401:
4397:
4396:
4392:
4385:
4381:
4373:
4369:
4362:
4358:
4345:
4344:
4340:
4335:. October 2014.
4326:
4322:
4321:
4317:
4312:. October 2014.
4303:
4299:
4298:
4294:
4281:
4277:
4268:
4266:
4262:
4255:
4251:
4250:
4246:
4237:
4236:
4232:
4224:
4217:
4213:
4212:
4208:
4198:
4197:
4193:
4180:
4179:
4175:
4167:
4163:
4162:
4158:
4149:
4147:
4138:
4137:
4133:
4128:
4124:
4116:
4112:
4107:
4103:
4093:
4091:
4079:
4078:
4074:
4066:
4062:
4053:
4052:
4048:
4039:
4038:
4034:
4024:
4022:
4014:
4010:
4009:
4005:
3994:
3990:
3973:
3967:
3965:
3958:"Archived copy"
3956:
3955:
3951:
3943:
3936:
3932:
3931:
3927:
3917:
3915:
3906:
3905:
3901:
3892:
3890:
3886:
3879:
3875:
3874:
3870:
3860:
3859:
3855:
3846:
3844:
3835:
3834:
3830:
3824:Wayback Machine
3815:
3811:
3798:
3797:
3793:
3780:
3779:
3775:
3766:
3764:
3751:
3750:
3746:
3737:
3735:
3731:
3724:
3720:
3719:
3715:
3706:
3705:
3696:
3688:
3681:
3677:
3676:
3667:
3658:
3656:
3652:
3645:
3641:
3640:
3633:
3622:
3620:
3616:
3606:
3605:
3601:
3591:
3590:
3586:
3577:
3576:
3572:
3564:
3560:
3554:BoatUS Magazine
3548:
3544:
3535:
3533:
3529:
3522:
3518:
3517:
3513:
3504:
3503:
3480:
3467:
3466:
3457:
3448:
3447:
3443:
3434:
3432:
3428:
3421:
3417:
3416:
3409:
3400:
3398:
3389:
3388:
3384:
3370:
3369:
3365:
3360:
3356:
3347:
3345:
3341:
3334:
3330:
3329:
3325:
3316:
3315:
3311:
3303:
3299:
3298:
3291:
3278:
3277:
3273:
3263:
3261:
3257:
3250:
3245:
3244:
3240:
3230:
3228:
3219:
3218:
3214:
3204:
3202:
3193:
3192:
3188:
3180:
3175:
3174:
3167:
3159:
3155:
3148:
3144:
3140:
3080:
3077:Electric beacon
3008:
2998:
2996:
2984:
2976:
2974:
2953:
2947:
2939:
2933:
2899:
2893:
2851:
2843:
2778:
2631:
2617:Wayback Machine
2605:Wayback Machine
2565:Wayback Machine
2490:
2474:
2469:
2451:121.5 MHz
2431:
2348:
2324:
2268:
2228:
2156:
2138:
2136:
2127:
2117:
2087:
2058:
2050:
2046:
2045:
2040:
2036:
2035:
2020:
1997:
1991:
1975:
1955:
1931:
1923:Wayback Machine
1814:
1788:EPIRBs with an
1775:
1700:Royal Air Force
1674:
1657:
1619:
1603:impact monitors
1599:
1559:impact monitors
1548:Wayback Machine
1502:
1492:
1470:
1445:
1401:
1393:
1373:
1368:
1293:Richelieu River
1210:In Canada, the
1205:
875:
642:
626:
580:
563:
523:
499:
483:
471:low Earth orbit
463:
458:
353:
266:
223:distress signal
200:for no charge.
190:New South Wales
132:
91:first responder
68:) is a type of
42:
35:
28:
23:
22:
15:
12:
11:
5:
6278:
6276:
6268:
6267:
6262:
6257:
6252:
6247:
6242:
6237:
6227:
6226:
6220:
6219:
6217:
6216:
6206:
6196:
6186:
6173:
6170:
6169:
6167:
6166:
6159:
6154:
6149:
6144:
6139:
6138:
6137:
6132:
6124:
6118:
6116:
6112:
6111:
6109:
6108:
6103:
6098:
6093:
6088:
6083:
6078:
6073:
6068:
6063:
6057:
6055:
6049:
6048:
6046:
6045:
6040:
6035:
6030:
6025:
6020:
6015:
6010:
6005:
6000:
5995:
5990:
5985:
5979:
5977:
5971:
5970:
5968:
5967:
5962:
5957:
5952:
5947:
5941:
5939:
5935:
5934:
5932:
5931:
5926:
5921:
5916:
5911:
5906:
5904:Space-division
5900:
5898:
5892:
5891:
5889:
5888:
5883:
5882:
5881:
5876:
5866:
5865:
5864:
5854:
5849:
5843:
5841:
5833:
5832:
5830:
5829:
5828:
5827:
5817:
5816:
5815:
5805:
5800:
5795:
5794:
5793:
5783:
5777:
5775:
5767:
5766:
5764:
5763:
5758:
5753:
5748:
5743:
5741:Camille Tissot
5738:
5733:
5728:
5723:
5718:
5716:Claude Shannon
5713:
5708:
5706:Tivadar Puskás
5703:
5698:
5693:
5688:
5683:
5678:
5676:Antonio Meucci
5673:
5668:
5663:
5658:
5653:
5648:
5646:Charles K. Kao
5643:
5638:
5633:
5628:
5623:
5621:Harold Hopkins
5618:
5613:
5608:
5603:
5598:
5593:
5588:
5583:
5578:
5573:
5568:
5563:
5558:
5553:
5548:
5543:
5538:
5533:
5528:
5523:
5521:Emile Berliner
5518:
5513:
5508:
5503:
5498:
5493:
5488:
5482:
5480:
5476:
5475:
5473:
5472:
5467:
5462:
5460:Videotelephony
5457:
5452:
5451:
5450:
5445:
5435:
5428:
5423:
5417:
5412:
5407:
5402:
5397:
5396:
5395:
5390:
5385:
5375:
5374:
5373:
5363:
5358:
5356:Radiotelephone
5353:
5348:
5343:
5338:
5333:
5328:
5323:
5322:
5321:
5311:
5306:
5301:
5296:
5291:
5286:
5281:
5276:
5271:
5266:
5261:
5260:
5259:
5254:
5249:
5244:
5242:Internet video
5234:
5233:
5232:
5227:
5222:
5217:
5207:
5202:
5197:
5192:
5187:
5182:
5176:
5174:
5168:
5167:
5162:
5160:
5159:
5152:
5145:
5137:
5128:
5127:
5125:
5124:
5114:
5103:
5100:
5099:
5084:Satellite link
5082: |
5056:ILS glide path
4986: |
4900:Mobile station
4874:
4872:
4864:
4863:
4856:Radio stations
4848:
4846:
4845:
4838:
4831:
4823:
4817:
4816:
4804:
4799:
4794:
4782:
4777:
4772:
4760:
4755:
4750:
4743:
4742:External links
4740:
4739:
4738:
4735:
4734:MED, 0735/2001
4732:
4726:
4721:
4718:
4716:
4715:
4694:
4677:
4660:
4615:
4598:
4553:
4539:
4521:
4496:
4470:Sport Aviation
4461:
4434:
4413:
4390:
4379:
4367:
4356:
4338:
4315:
4292:
4275:
4244:
4241:. August 2001.
4230:
4206:
4191:
4173:
4156:
4131:
4122:
4110:
4101:
4072:
4060:
4046:
4032:
4003:
3988:
3949:
3925:
3899:
3868:
3853:
3828:
3826:Canada Gazette
3809:
3791:
3773:
3744:
3713:
3710:. August 2001.
3694:
3691:on 2016-06-14.
3665:
3631:
3614:
3599:
3584:
3570:
3558:
3542:
3511:
3506:"Participants"
3478:
3455:
3441:
3407:
3382:
3363:
3354:
3323:
3309:
3289:
3271:
3238:
3212:
3186:
3165:
3153:
3141:
3139:
3136:
3135:
3134:
3129:
3123:
3118:
3115:Survival radio
3112:
3106:
3100:
3095:
3089:
3083:
3074:
3068:
3062:
3056:
3050:
3044:
3038:
3032:
3027:
3021:
3015:
3007:
3006:
2994:
2973:
2970:
2949:Main article:
2946:
2943:
2935:Main article:
2932:
2929:
2895:Main article:
2892:
2889:
2868:are allocated
2850:
2847:
2842:
2839:
2838:
2837:
2836:
2835:
2834:
2833:
2830:
2827:
2826:Strength tests
2824:
2821:
2818:
2807:
2806:
2805:
2797:
2796:
2795:
2789:
2788:
2787:
2777:
2774:
2773:
2772:
2771:
2770:
2763:
2760:
2759:
2758:
2755:
2749:
2746:
2745:
2744:
2741:
2738:
2735:
2732:
2729:
2726:
2723:
2720:
2716:Cospas-Sarsat
2714:
2713:
2712:
2705:
2702:
2699:
2691:
2690:
2689:
2686:
2683:
2680:
2672:
2671:
2670:
2667:
2664:
2661:
2658:
2655:
2647:
2644:
2641:
2630:
2629:Specifications
2627:
2626:
2625:
2619:
2607:
2595:
2589:
2585:Netherlands –
2583:
2577:
2571:
2554:
2547:
2540:
2529:
2512:
2511:
2508:
2505:
2489:
2486:
2473:
2470:
2468:
2465:
2464:
2463:
2460:
2449:
2438:
2430:
2427:
2426:
2425:
2422:
2419:
2416:
2413:
2410:
2407:
2404:
2401:
2398:
2395:
2392:
2389:
2386:
2383:
2380:
2377:
2374:
2371:
2364:
2363:
2360:carrier signal
2352:
2347:
2344:
2323:
2320:
2319:
2318:
2315:
2304:
2285:
2278:
2275:
2267:
2264:
2263:
2262:
2255:
2254:(DASS) system.
2248:
2244:
2240:
2227:
2224:
2211:
2210:
2207:
2204:
2186:
2183:
2155:
2152:
2135:
2132:
2126:
2125:Beacon content
2123:
2122:
2121:
2116:
2113:
2098:
2097:
2094:
2086:
2083:
2019:
2016:
2012:
2011:
2008:
2005:
1993:Main article:
1990:
1987:
1974:
1971:
1954:
1951:
1930:
1927:
1900:
1899:
1896:
1882:
1870:
1855:
1848:
1830:
1829:
1826:
1813:
1810:
1774:
1771:
1770:
1769:
1766:
1763:
1759:
1756:
1745:
1728:
1717:
1709:
1706:
1703:
1685:
1678:
1673:
1670:
1662:
1661:
1656:
1653:
1645:
1644:
1641:
1638:
1635:
1632:
1629:
1626:
1618:
1615:
1598:
1597:ELT activation
1595:
1491:
1488:
1469:
1466:
1444:
1441:
1400:
1397:
1392:
1389:
1372:
1371:United Kingdom
1369:
1367:
1364:
1361:
1360:
1358:
1352:
1350:
1344:
1343:
1341:
1338:
1335:
1329:
1328:
1326:
1320:
1317:
1311:
1310:
1308:
1307:
1306:
1296:
1289:
1287:Saguenay River
1283:
1276:
1267:
1264:
1258:
1257:
1255:
1252:
1249:
1243:
1242:
1239:
1236:
1233:
1204:
1201:
1194:
1193:
1188:
1186:
1184:
1181:
1177:
1176:
1171:
1169:
1167:
1164:
1157:
1156:
1151:
1149:
1147:
1144:
1137:
1136:
1131:
1129:
1127:
1124:
1117:
1116:
1111:
1109:
1107:
1104:
1102:(RCC Seattle)
1097:
1096:
1091:
1089:
1087:
1084:
1074:
1073:
1068:
1066:
1064:
1061:
1054:
1053:
1048:
1046:
1044:
1041:
1034:
1033:
1028:
1026:
1024:
1021:
1014:
1013:
1008:
1006:
1004:
1001:
999:(RCC Norfolk)
994:
993:
988:
986:
984:
981:
974:
973:
970:
968:
966:
963:
959:
958:
956:
949:
947:
943:
942:
940:
937:
934:
931:
921:
920:
918:
912:
909:
906:
900:
899:
896:
893:
890:
887:
874:
871:
868:
867:
865:
863:
860:
856:
855:
853:
851:
848:
844:
843:
841:
839:
836:
832:
831:
829:
827:
824:
820:
819:
817:
815:
812:
808:
807:
805:
803:
800:
796:
795:
793:
791:
788:
784:
783:
781:
779:
776:
772:
771:
769:
767:
764:
760:
759:
757:
755:
752:
748:
747:
745:
743:
740:
736:
735:
733:
731:
728:
724:
723:
721:
719:
716:
712:
711:
709:
707:
704:
700:
699:
697:
695:
692:
688:
687:
685:
683:
680:
673:
672:
670:
668:
665:
661:
660:
657:
654:
651:
641:
638:
625:
622:
598:
597:
594:
591:
588:
579:
576:
562:
559:
522:
519:
515:satellite pass
498:
495:
482:
479:
462:
459:
457:
454:
442:
441:
440:
439:
432:
426:
425:
424:
421:
415:
414:
413:
410:
384:
383:
380:
377:
374:
371:
368:
352:
349:
348:
347:
344:
341:
330:
329:
328:
327:
319:
313:
312:
311:
304:
303:
302:
265:
262:
231:Doppler effect
207:
206:
205:
204:
175:
174:
173:
164:
158:
157:
156:
147:
146:
145:
131:
128:
118:, and people.
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
6277:
6266:
6263:
6261:
6258:
6256:
6253:
6251:
6248:
6246:
6243:
6241:
6238:
6236:
6233:
6232:
6230:
6215:
6207:
6205:
6197:
6195:
6187:
6185:
6175:
6174:
6171:
6164:
6160:
6158:
6155:
6153:
6150:
6148:
6145:
6143:
6140:
6136:
6133:
6131:
6128:
6127:
6125:
6123:
6120:
6119:
6117:
6113:
6107:
6104:
6102:
6099:
6097:
6094:
6092:
6089:
6087:
6084:
6082:
6079:
6077:
6074:
6072:
6069:
6067:
6064:
6062:
6059:
6058:
6056:
6054:
6050:
6044:
6041:
6039:
6036:
6034:
6031:
6029:
6026:
6024:
6021:
6019:
6016:
6014:
6011:
6009:
6006:
6004:
6001:
5999:
5996:
5994:
5991:
5989:
5986:
5984:
5981:
5980:
5978:
5976:
5972:
5966:
5963:
5961:
5958:
5956:
5953:
5951:
5948:
5946:
5943:
5942:
5940:
5936:
5930:
5929:Code-division
5927:
5925:
5922:
5920:
5917:
5915:
5914:Time-division
5912:
5910:
5907:
5905:
5902:
5901:
5899:
5897:
5893:
5887:
5884:
5880:
5877:
5875:
5872:
5871:
5870:
5867:
5863:
5860:
5859:
5858:
5855:
5853:
5850:
5848:
5845:
5844:
5842:
5840:and switching
5838:
5834:
5826:
5823:
5822:
5821:
5818:
5814:
5811:
5810:
5809:
5806:
5804:
5801:
5799:
5796:
5792:
5791:optical fiber
5789:
5788:
5787:
5784:
5782:
5781:Coaxial cable
5779:
5778:
5776:
5774:
5768:
5762:
5759:
5757:
5754:
5752:
5749:
5747:
5744:
5742:
5739:
5737:
5734:
5732:
5729:
5727:
5724:
5722:
5719:
5717:
5714:
5712:
5709:
5707:
5704:
5702:
5699:
5697:
5696:Radia Perlman
5694:
5692:
5689:
5687:
5684:
5682:
5679:
5677:
5674:
5672:
5669:
5667:
5664:
5662:
5659:
5657:
5654:
5652:
5649:
5647:
5644:
5642:
5639:
5637:
5634:
5632:
5629:
5627:
5624:
5622:
5619:
5617:
5614:
5612:
5609:
5607:
5604:
5602:
5599:
5597:
5594:
5592:
5589:
5587:
5586:Lee de Forest
5584:
5582:
5581:Thomas Edison
5579:
5577:
5574:
5572:
5571:Donald Davies
5569:
5567:
5564:
5562:
5559:
5557:
5556:Claude Chappe
5554:
5552:
5549:
5547:
5544:
5542:
5539:
5537:
5534:
5532:
5529:
5527:
5524:
5522:
5519:
5517:
5514:
5512:
5509:
5507:
5504:
5502:
5499:
5497:
5494:
5492:
5489:
5487:
5484:
5483:
5481:
5477:
5471:
5468:
5466:
5463:
5461:
5458:
5456:
5453:
5449:
5446:
5444:
5441:
5440:
5439:
5436:
5434:
5433:
5429:
5427:
5424:
5421:
5418:
5416:
5413:
5411:
5408:
5406:
5403:
5401:
5400:Smoke signals
5398:
5394:
5391:
5389:
5386:
5384:
5381:
5380:
5379:
5378:Semiconductor
5376:
5372:
5369:
5368:
5367:
5364:
5362:
5359:
5357:
5354:
5352:
5349:
5347:
5344:
5342:
5339:
5337:
5334:
5332:
5329:
5327:
5324:
5320:
5317:
5316:
5315:
5312:
5310:
5307:
5305:
5302:
5300:
5297:
5295:
5292:
5290:
5287:
5285:
5282:
5280:
5277:
5275:
5272:
5270:
5267:
5265:
5262:
5258:
5255:
5253:
5250:
5248:
5245:
5243:
5240:
5239:
5238:
5237:Digital media
5235:
5231:
5228:
5226:
5223:
5221:
5218:
5216:
5213:
5212:
5211:
5208:
5206:
5203:
5201:
5198:
5196:
5193:
5191:
5188:
5186:
5183:
5181:
5178:
5177:
5175:
5173:
5169:
5165:
5158:
5153:
5151:
5146:
5144:
5139:
5138:
5135:
5123:
5119:
5115:
5113:
5105:
5104:
5101:
5097:
5094: |
5093:
5090: |
5089:
5086: |
5085:
5081:
5078: |
5077:
5074: |
5073:
5070: |
5069:
5066: |
5065:
5062: |
5061:
5060:Marker beacon
5058: |
5057:
5054: |
5053:
5052:ILS localizer
5050: |
5049:
5046: |
5045:
5042: |
5041:
5038: |
5037:
5036:Primary radar
5034: |
5033:
5030: |
5029:
5026: |
5025:
5022: |
5021:
5018: |
5017:
5014: |
5013:
5010: |
5009:
5006: |
5005:
5002: |
5001:
4998: |
4997:
4994: |
4993:
4990: |
4989:
4985:
4982: |
4981:
4978: |
4977:
4974: |
4973:
4970: |
4969:
4966: |
4965:
4962: |
4961:
4958: |
4957:
4954: |
4953:
4950: |
4949:
4946: |
4945:
4942: |
4941:
4938: |
4937:
4934: |
4933:
4932:Coast station
4930: |
4929:
4926: |
4925:
4922: |
4921:
4918: |
4917:
4914: |
4913:
4910: |
4909:
4906: |
4905:
4902: |
4901:
4898: |
4897:
4894: |
4893:
4892:Fixed station
4890: |
4889:
4886: |
4885:
4884:Space station
4882: |
4881:
4880:Earth station
4878: |
4877:
4873:
4865:
4861:
4857:
4852:
4844:
4839:
4837:
4832:
4830:
4825:
4824:
4821:
4815:
4811:
4808:
4805:
4803:
4800:
4798:
4795:
4791:
4787:
4783:
4781:
4778:
4776:
4773:
4771:
4767:
4764:
4761:
4759:
4756:
4754:
4751:
4749:
4746:
4745:
4741:
4736:
4733:
4731:
4727:
4724:
4723:
4719:
4711:
4705:
4697:
4695:9789280115079
4691:
4687:
4681:
4678:
4670:
4664:
4661:
4656:
4650:
4636:on 2018-02-08
4632:
4625:
4619:
4616:
4608:
4602:
4599:
4594:
4588:
4574:on 2008-07-04
4570:
4563:
4557:
4554:
4549:
4543:
4540:
4535:
4531:
4525:
4522:
4511:on 2007-10-09
4510:
4506:
4500:
4497:
4492:
4479:
4471:
4465:
4462:
4454:
4447:
4441:
4439:
4435:
4430:
4423:
4417:
4414:
4409:
4408:
4400:
4394:
4391:
4388:
4383:
4380:
4376:
4371:
4368:
4365:
4360:
4357:
4352:
4348:
4342:
4339:
4334:
4333:
4325:
4319:
4316:
4311:
4310:
4302:
4296:
4293:
4289:
4285:
4279:
4276:
4265:on 2018-02-07
4261:
4254:
4248:
4245:
4240:
4234:
4231:
4223:
4216:
4210:
4207:
4202:
4195:
4192:
4187:
4183:
4177:
4174:
4166:
4160:
4157:
4146:on 2019-05-06
4145:
4141:
4135:
4132:
4126:
4123:
4119:
4114:
4111:
4105:
4102:
4089:
4084:
4076:
4073:
4069:
4064:
4061:
4056:
4050:
4047:
4042:
4036:
4033:
4020:
4019:Flying Safety
4013:
4012:"Down at Sea"
4007:
4004:
4000:
3997:
3992:
3989:
3984:
3978:
3964:on 2009-10-12
3963:
3959:
3953:
3950:
3942:
3935:
3929:
3926:
3913:
3909:
3903:
3900:
3889:on 2008-07-04
3885:
3878:
3872:
3869:
3864:
3857:
3854:
3843:on 2009-05-15
3842:
3838:
3832:
3829:
3825:
3821:
3818:
3813:
3810:
3805:
3801:
3795:
3792:
3787:
3783:
3777:
3774:
3763:on 2007-12-05
3762:
3758:
3754:
3748:
3745:
3734:on 2017-04-26
3730:
3723:
3717:
3714:
3709:
3703:
3701:
3699:
3695:
3687:
3680:
3674:
3672:
3670:
3666:
3655:on 2005-09-05
3651:
3644:
3638:
3636:
3632:
3629:
3625:
3618:
3615:
3610:
3603:
3600:
3595:
3588:
3585:
3580:
3574:
3571:
3567:
3562:
3559:
3556:. March 2007.
3555:
3551:
3546:
3543:
3532:on 2017-01-30
3528:
3521:
3515:
3512:
3507:
3501:
3499:
3497:
3495:
3493:
3491:
3489:
3487:
3485:
3483:
3479:
3474:
3470:
3464:
3462:
3460:
3456:
3451:
3445:
3442:
3431:on 2017-09-29
3427:
3420:
3414:
3412:
3408:
3397:on 2018-02-09
3396:
3392:
3386:
3383:
3378:
3374:
3367:
3364:
3358:
3355:
3344:on 2017-04-26
3340:
3333:
3327:
3324:
3319:
3313:
3310:
3302:
3296:
3294:
3290:
3285:
3281:
3275:
3272:
3256:
3249:
3242:
3239:
3226:
3222:
3216:
3213:
3201:on 2012-08-06
3200:
3196:
3190:
3187:
3179:
3172:
3170:
3166:
3163:
3157:
3154:
3151:
3146:
3143:
3137:
3133:
3130:
3127:
3124:
3122:
3119:
3116:
3113:
3110:
3107:
3104:
3101:
3099:
3096:
3093:
3090:
3087:
3084:
3078:
3075:
3072:
3069:
3066:
3063:
3060:
3057:
3054:
3051:
3048:
3045:
3042:
3039:
3036:
3033:
3031:
3028:
3025:
3022:
3019:
3016:
3013:
3010:
3009:
3005:
2995:
2993:
2988:
2983:
2979:
2971:
2969:
2967:
2962:
2958:
2952:
2944:
2942:
2938:
2930:
2928:
2926:
2921:
2919:
2915:
2912:
2908:
2904:
2898:
2890:
2888:
2886:
2882:
2878:
2873:
2871:
2867:
2863:
2858:
2856:
2855:man-overboard
2848:
2846:
2840:
2831:
2828:
2825:
2822:
2819:
2816:
2815:
2814:
2811:
2810:
2808:
2804:
2801:
2800:
2798:
2793:
2792:
2790:
2785:
2784:
2783:
2780:
2779:
2775:
2767:
2766:
2764:
2761:
2756:
2753:
2752:
2750:
2747:
2742:
2739:
2736:
2733:
2730:
2727:
2724:
2721:
2718:
2717:
2715:
2710:
2706:
2703:
2700:
2697:
2696:
2695:
2692:
2687:
2684:
2681:
2678:
2677:
2676:
2673:
2668:
2665:
2662:
2659:
2656:
2653:
2652:
2648:
2645:
2642:
2639:
2638:
2636:
2635:
2634:
2628:
2624:
2620:
2618:
2614:
2611:
2608:
2606:
2602:
2599:
2596:
2594:
2590:
2588:
2584:
2582:
2578:
2576:
2572:
2570:
2566:
2562:
2559:
2555:
2552:
2548:
2545:
2541:
2538:
2534:
2530:
2528:
2524:
2523:
2522:
2519:
2517:
2509:
2506:
2503:
2502:
2501:
2499:
2495:
2487:
2485:
2483:
2479:
2478:North America
2471:
2466:
2461:
2458:
2454:
2450:
2447:
2443:
2440:The obsolete
2439:
2436:
2433:
2432:
2428:
2423:
2420:
2417:
2414:
2411:
2408:
2405:
2402:
2399:
2396:
2393:
2390:
2387:
2384:
2381:
2378:
2375:
2372:
2369:
2368:
2367:
2361:
2357:
2354:406 MHz
2353:
2350:
2349:
2345:
2343:
2341:
2337:
2336:Cospas-Sarsat
2333:
2329:
2321:
2316:
2313:
2309:
2305:
2302:
2298:
2294:
2290:
2286:
2283:
2279:
2276:
2273:
2272:
2271:
2265:
2260:
2256:
2253:
2249:
2245:
2241:
2238:
2234:
2230:
2229:
2225:
2223:
2221:
2216:
2208:
2205:
2203:
2199:
2195:
2191:
2187:
2184:
2181:
2180:
2179:
2176:
2173:
2169:
2165:
2161:
2160:homing beacon
2153:
2151:
2133:
2131:
2124:
2119:
2118:
2115:Obsolete PLBs
2114:
2112:
2110:
2106:
2101:
2095:
2092:
2091:
2090:
2084:
2082:
2079:
2076:
2073:
2070:
2056:
2032:
2024:
2017:
2015:
2009:
2006:
2003:
2002:
2001:
1996:
1988:
1986:
1984:
1980:
1972:
1966:
1962:
1960:
1952:
1950:
1946:
1944:
1940:
1934:
1928:
1926:
1924:
1920:
1917:
1914:'s statement
1913:
1907:
1905:
1897:
1894:
1890:
1886:
1883:
1880:
1875:
1871:
1868:
1864:
1863:survival suit
1860:
1856:
1853:
1849:
1846:
1842:
1837:
1836:
1835:
1834:
1827:
1824:
1823:
1822:
1821:
1817:
1811:
1806:
1801:
1797:
1795:
1791:
1786:
1784:
1779:
1772:
1767:
1764:
1762:temperatures.
1760:
1757:
1754:
1750:
1746:
1743:
1739:
1734:
1729:
1726:
1722:
1718:
1714:
1710:
1707:
1704:
1701:
1697:
1696:Fleet Air Arm
1693:
1690:
1686:
1683:
1679:
1676:
1675:
1671:
1669:
1667:
1659:
1658:
1655:Obsolete ELTs
1654:
1652:
1650:
1642:
1639:
1636:
1633:
1630:
1627:
1624:
1623:
1622:
1616:
1614:
1612:
1608:
1605:activated by
1604:
1596:
1594:
1592:
1591:Cospas-Sarsat
1586:
1584:
1580:
1576:
1570:
1566:
1564:
1560:
1555:
1553:
1549:
1545:
1542:
1538:
1533:
1531:
1526:
1524:
1520:
1516:
1496:
1489:
1487:
1485:
1481:
1479:
1475:
1467:
1465:
1461:
1459:
1454:
1451:
1450:Cospas-Sarsat
1442:
1440:
1437:
1434:
1431:
1428:
1425:
1422:
1419:
1417:
1413:
1408:
1406:
1398:
1396:
1390:
1388:
1384:
1382:
1378:
1370:
1365:
1359:
1357:
1353:
1351:
1349:
1346:
1345:
1342:
1339:
1336:
1334:
1331:
1330:
1327:
1325:
1321:
1318:
1316:
1313:
1312:
1309:
1305:
1301:
1297:
1294:
1290:
1288:
1284:
1281:
1277:
1274:
1270:
1269:
1268:
1265:
1263:
1260:
1259:
1256:
1253:
1250:
1248:
1245:
1244:
1240:
1237:
1234:
1231:
1230:
1227:
1225:
1221:
1217:
1213:
1208:
1202:
1200:
1192:
1191:(671)355-4824
1189:
1187:
1185:
1182:
1179:
1178:
1175:
1174:(787)289-2042
1172:
1170:
1168:
1165:
1163:
1159:
1158:
1155:
1154:(907)463-2000
1152:
1150:
1148:
1145:
1143:
1142:(RCC Juneau)
1139:
1138:
1135:
1134:(808)535-3333
1132:
1130:
1128:
1125:
1123:
1119:
1118:
1115:
1114:(206)220-7001
1112:
1110:
1108:
1105:
1103:
1099:
1098:
1095:
1094:(510)437-3701
1092:
1090:
1088:
1085:
1083:
1080:
1076:
1075:
1072:
1071:(216)902-6117
1069:
1067:
1065:
1062:
1060:
1056:
1055:
1052:
1051:(504)589-6225
1049:
1047:
1045:
1042:
1040:
1036:
1035:
1032:
1031:(305)415-6800
1029:
1027:
1025:
1022:
1020:
1016:
1015:
1012:
1011:(757)398-6231
1009:
1007:
1005:
1002:
1000:
996:
995:
992:
991:(617)223-8555
989:
987:
985:
982:
980:
979:(RCC Boston)
976:
975:
972:757-398-6700
971:
969:
967:
964:
961:
960:
957:
954:
948:
945:
944:
941:
938:
935:
932:
930:
927:operates the
926:
923:
922:
919:
917:
913:
910:
907:
905:
902:
901:
898:Phone number
897:
894:
891:
888:
885:
884:
878:
873:United States
872:
866:
864:
861:
858:
857:
854:
852:
849:
846:
845:
842:
840:
837:
834:
833:
830:
828:
825:
822:
821:
818:
816:
813:
810:
809:
806:
804:
801:
798:
797:
794:
792:
789:
786:
785:
782:
780:
777:
774:
773:
770:
768:
765:
762:
761:
758:
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296:
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291:
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285:COsmicheskaya
282:
278:
274:
270:
269:Cospas-Sarsat
263:
261:
259:
255:
251:
247:
242:
240:
236:
235:trilateration
232:
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119:
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92:
88:
87:COSPAS-SARSAT
84:
79:
75:
71:
67:
63:
54:
46:
40:
33:
19:
5896:Multiplexing
5771:Transmission
5736:Nikola Tesla
5726:Henry Sutton
5681:Samuel Morse
5611:Robert Hooke
5576:Amos Dolbear
5511:John Bardeen
5430:
5410:Telautograph
5314:Mobile phone
5269:Edholm's law
5252:social media
5185:Broadcasting
5072:Space system
4952:Port station
4940:Ship station
4916:Base station
4908:Land station
4802:RCC Messages
4685:
4680:
4663:
4638:. Retrieved
4631:the original
4618:
4601:
4576:. Retrieved
4569:the original
4556:
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4524:
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4509:the original
4499:
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4478:cite journal
4469:
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4260:the original
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4144:the original
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4087:
4075:
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4035:
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3962:the original
3952:
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3928:
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3902:
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3884:the original
3871:
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3841:the original
3831:
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3803:
3794:
3786:the original
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3747:
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3729:the original
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3650:the original
3617:
3602:
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3573:
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3553:
3545:
3534:. Retrieved
3527:the original
3514:
3472:
3444:
3433:. Retrieved
3426:the original
3399:. Retrieved
3395:the original
3385:
3376:
3366:
3357:
3346:. Retrieved
3339:the original
3326:
3312:
3284:the original
3274:
3262:. Retrieved
3255:the original
3241:
3229:. Retrieved
3225:the original
3215:
3203:. Retrieved
3199:the original
3189:
3161:
3156:
3145:
2954:
2940:
2922:
2900:
2880:
2876:
2874:
2859:
2852:
2844:
2813:USCG 160.162
2649:
2632:
2542:Australia –
2520:
2513:
2496:(SOLAS) and
2491:
2488:Registration
2475:
2365:
2331:
2325:
2269:
2212:
2201:
2194:registration
2177:
2157:
2148:
2128:
2102:
2099:
2088:
2080:
2077:
2074:
2071:
2068:
2033:
2029:
2013:
1998:
1976:
1958:
1956:
1947:
1935:
1932:
1908:
1901:
1892:
1878:
1866:
1851:
1844:
1832:
1831:
1819:
1818:
1815:
1787:
1780:
1776:
1731:Health Act.
1663:
1646:
1620:
1600:
1587:
1571:
1567:
1556:
1534:
1527:
1512:
1482:
1471:
1462:
1455:
1446:
1438:
1435:
1432:
1429:
1426:
1423:
1420:
1409:
1402:
1394:
1385:
1374:
1323:
1300:Ottawa River
1209:
1206:
1197:
1190:
1173:
1161:
1153:
1141:
1133:
1121:
1113:
1101:
1093:
1081:
1078:
1070:
1058:
1050:
1038:
1030:
1019:(RCC Miami)
1018:
1010:
998:
990:
978:
876:
643:
627:
618:
608:or aircraft
603:
599:
581:
572:
568:Soviet Union
564:
551:
548:
544:
532:triangulates
524:
511:
507:
500:
488:
484:
475:
468:
464:
443:
401:
397:
385:
362:
335:
331:
310:information.
292:
287:
284:
276:
267:
243:
220:
208:
177:
166:
160:
149:
138:
133:
124:
120:
114:watercraft,
101:
96:GPS receiver
65:
61:
59:
6096:NPL network
5808:Radio waves
5746:Alfred Vail
5656:Hedy Lamarr
5641:Dawon Kahng
5601:Elisha Gray
5561:Yogen Dalal
5486:Nasir Ahmed
5420:Teleprinter
5284:Heliographs
5092:Feeder link
4094:October 10,
3804:rgl.faa.gov
3264:20 February
2786:SOLAS 74.95
2537:CFB Trenton
2482:Australasia
2322:Frequencies
2312:de-register
2215:hexadecimal
1939:hydrostatic
1753:Nick Begich
1698:and later,
1643:S: survival
1266:QuebecCity
1241:SAR Agency
953:Coast Guard
895:SAR agency
659:SAR Agency
610:tail number
6229:Categories
6142:Antarctica
6101:Toasternet
6023:Television
5506:Paul Baran
5438:Television
5422:(teletype)
5415:Telegraphy
5393:transistor
5371:Phryctoria
5341:Photophone
5319:Smartphone
5309:Mass media
5068:Radiosonde
4720:References
4640:2018-02-07
4578:2007-09-06
4515:2007-10-01
4288:1885544278
4269:2018-02-06
4150:2018-02-08
3968:2009-09-22
3918:28 January
3893:2007-09-06
3847:2009-11-20
3767:2007-09-06
3738:2018-02-08
3659:2018-02-06
3536:2018-02-09
3435:2018-02-08
3401:2018-02-08
3348:2018-02-08
2591:Denmark -
2442:Inmarsat-E
2332:recognized
2111:) exists.
2105:registered
1979:submarines
1893:Inmarsat E
1885:Inmarsat-E
1874:Marine VHF
1872:Class C –
1843:(FCC) and
1749:Hale Boggs
1611:aerobatics
835:Chile RCC
811:Venezuela
682:BERMUDASP
561:Satellites
326:confirmed.
229:using the
112:distressed
106:that aids
83:satellites
6126:Americas
6115:Locations
6086:Internet2
5847:Bandwidth
5551:Vint Cerf
5448:streaming
5426:Telephone
5366:Semaphore
5257:streaming
4704:cite book
3782:"The ELT"
3231:9 October
2992:Transport
2918:liferafts
2794:ISO 15734
2573:France –
2556:Greece –
2531:Canada –
2301:longitude
2266:Hex codes
2259:see below
1649:see below
1337:VICTORIA
1235:SRR Name
965:LANTAREA
889:SRR name
847:Paraguay
838:ChileRCC
718:DOMREPSP
703:Colombia
653:SRR Name
491:121.5 MHz
215:satellite
6194:Category
6081:Internet
6071:CYCLADES
5988:Ethernet
5938:Concepts
5862:terminal
5813:wireless
5636:Bob Kahn
5479:Pioneers
5304:Internet
5195:Cable TV
5112:Category
4810:Archived
4790:Archived
4766:Archived
4649:cite web
4587:cite web
3977:cite web
3820:Archived
3611:. AVweb.
3053:AIS-SART
3004:Aviation
2972:See also
2897:AIS-SART
2891:AIS SART
2660:TSO-C91a
2613:Archived
2601:Archived
2579:Italy –
2561:Archived
2446:Inmarsat
2342:system.
2308:register
2297:latitude
2282:firmware
1919:Archived
1631:F: Fixed
1544:Archived
1319:TRENTON
1251:HALIFAX
1086:PACAREA
859:Uruguay
823:Bolivia
727:Ecuador
694:COCESNA
676:Bermuda
640:Americas
632:and the
279:) is an
273:Cold War
250:AIS-SART
248:(SART),
184:; e.g.,
116:aircraft
6240:Beacons
6214:Commons
6204:Outline
6157:Oceania
6076:FidoNet
6061:ARPANET
5874:circuit
5443:digital
5172:History
4868:desig-
4290:, p 287
4025:11 July
3628:YouTube
3596:. NASA.
2978:Portals
2769:results
2679:DO-127?
2657:TSO-C91
2472:License
2293:GLONASS
2196:or its
2172:GLONASS
2049:⁄
2039:⁄
1807:efforts
1716:rescue.
1607:g-force
1563:g-force
1541:TSO-C91
1535:As per
1418:(MRCC)
1407:(MRCC)
1183:MARSEC
787:Panama
778:NANTSP
766:MEXTEL
754:MEXISP
751:Mexico
739:Guyana
706:COLMSP
527:Doppler
436:GOES-16
428:GEOSAR
417:MEOSAR
406:LEOSAR
323:Galileo
281:acronym
6152:Europe
6122:Africa
6106:Usenet
6066:BITNET
6003:Mobile
5879:packet
5388:MOSFET
5383:device
5180:Beacon
5122:Portal
4870:nation
4692:
4286:
3999:Flight
2711:(SEND)
2688:DO-147
2685:DO-146
2682:DO-145
2546:(AMSA)
2252:MEOSAR
2237:LEOSAR
2233:GEOSAR
2164:GEOSAR
1460:page.
1391:Russia
1366:Europe
1203:Canada
1166:SANJN
1146:CGD17
1126:CGD14
1106:CGD13
1063:CGD09
1043:CGD08
1023:CGD07
1003:CGD05
983:CGD01
933:AKRCC
908:AFRCC
850:PARSP
826:BOLSP
814:VZMCC
790:PANSP
742:GUYSP
667:ARMCC
277:КОСПАС
256:, and
198:hikers
161:SEPIRB
78:locate
6135:South
6130:North
6091:JANET
6028:Telex
6018:Radio
5857:Nodes
5852:Links
5773:media
5351:Radio
5336:Pager
5264:Drums
5230:video
5225:image
5215:audio
5032:Radar
4730:GMDSS
4672:(PDF)
4634:(PDF)
4627:(PDF)
4610:(PDF)
4572:(PDF)
4565:(PDF)
4456:(PDF)
4449:(PDF)
4425:(PDF)
4402:(PDF)
4327:(PDF)
4304:(PDF)
4263:(PDF)
4256:(PDF)
4225:(PDF)
4218:(PDF)
4168:(PDF)
4015:(PDF)
3944:(PDF)
3937:(PDF)
3887:(PDF)
3880:(PDF)
3732:(PDF)
3725:(PDF)
3689:(PDF)
3682:(PDF)
3653:(PDF)
3646:(PDF)
3530:(PDF)
3523:(PDF)
3429:(PDF)
3422:(PDF)
3342:(PDF)
3335:(PDF)
3304:(PDF)
3258:(PDF)
3251:(PDF)
3205:9 Oct
3181:(PDF)
3138:Notes
3121:TACBE
3065:RECCO
2553:(MCA)
2109:9-1-1
1889:GMDSS
862:URSP
802:TTSP
730:ECSP
650:SPOC
536:orbit
258:RECCO
186:9-1-1
150:EPIRB
66:EPIRB
6147:Asia
6033:UUCP
5993:ISDN
4710:link
4690:ISBN
4655:link
4593:link
4491:help
4429:ICAO
4284:ISBN
4096:2017
4027:2021
3983:link
3920:2024
3266:2010
3233:2012
3207:2012
2945:APRS
2925:MMSI
2903:SART
2870:MMSI
2791:ISO
2765:IEC
2762:ICAO
2751:ITU
2637:FAA
2575:CNES
2567:and
2514:The
2480:and
2455:± 6
2299:and
2235:and
2190:MMSI
2044:to 2
1912:NOAA
1794:MMSI
1783:RTCM
1781:The
1751:and
1725:DC-3
1680:The
1581:and
1530:RTCA
1484:NASA
1478:AOPA
1399:Asia
1291:the
1271:the
1232:RCC
1222:and
1214:and
951:The
886:RCC
606:MMSI
389:USCG
233:for
167:SSAS
139:ELT
6038:WAN
6008:NGN
5998:LAN
5279:Fax
5220:DCT
3626:on
2961:GPS
2914:AIS
2911:VHF
2907:GPS
2866:AIS
2864:or
2862:DSC
2748:IMO
2476:In
2457:kHz
2453:VHF
2356:UHF
2291:or
2289:GPS
2170:or
2168:GPS
1861:or
1805:SAR
1790:AIS
1651:).
1583:GPS
1579:VOR
1517:or
1414:'s
239:GPS
178:PLB
60:An
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