uscg/noaa sarsat conference 2011 epirb’s how they work

USCG/NOAA SARSAT CONFERENCE 2011

EPIRB’sHow They Work

How the System Works

04/19/23 L. Yarbrough/D7CFVS

C/S 406 MHz Beacons• COSPAS-SARSAT 406 MHz Beacons

EPIRB Emergency Position Indicating Radio

PLB Personal Locator Beacon

ELT Emergency Locator Beacon

SSAS Ship Security Alert System


Types of Beacons

• EPIRB 406 MHz

Automatic activation when out of bracket and wet.

Floats up right able to transmit

Strobe light

Min 48 hour transmit

Some GPS enabled

Maritime Distress Beacon


406 MHz VDR

• 406 MHz Voyage Data Recorder

• EPIRB with black box data recorder built in.

• Records last 12 hr “Black Box” data for ship.


Types of Beacons

• PLBManual activationCarried on persons May or may not floatHeld out of water to

transmitNO Strobe light requiredMin 24 hour transmit Some GPS Enabled

Distress Beacon for

Personal Use (Land Rescue)


Types of Beacons ELT

Operational Applications

• Automatic Fixed - AF• Automatic Portable - AP• Survival Equipment – S

– Class A (buoyant)– Class B (non-buoyant)

• Automatic Deployable - AD

• 406 MHz ELTs406/121.5 MHz

24 hr Transmitter

“ON-OFF-ARMED-RESET” controls

ELT activated by pilot, crash forces or water activated.

Aviation Distress Beacon


Types of BeaconsELT

Aviation Distress Beacon

AD

AF

S Class A

S Class B


AP

SSAS

• 406 MHz Ship Security Alert System (SSAS)

• All SOLAS vsls on international voyages.

• Two stealth switches for remote activation.

• Alert goes to Atlantic Area.


SENDSATELLITE

EMERGENCY

NOTIFICATION DEVICES

• Operate over any satellite system except Cospas-Sarsat.

• Provide individuals in remote areas a means to alert others of an emergency situation and to aid search and rescue personnel to locate those in distress.


C/S 406 MHz Beacon Operational Requirements

• Beacon 406 MHz Signal - 5 Watts

• Short bursts at approximately 50 second intervals (varies between 47.5 and 52.5 s), with a transmission time of 440 ms or 520 ms.

• Transmits in the 406.0 to 406.1 MHz band.

• Beacon Self Test


C/S 406 MHz Beacon Transmission

Transmission consists:

– Unmodulated carrier, for 160 ms,

– Short synchronization signal, signal inverted for test,

– Digital message that provides stored information (identification, nationality, type of user),

– Optionally, current information like, type of emergency and estimated location.


15 Hex ID• C/S Beacon identification, when decoded

into its 15 character hexadecimal representation, which is the EPIRB’s unique identifier.

• A C/S Decode Program is available at: http://www.cospas-sarsat.org/index.php?option=com_beacondecode&task=showBeacon&Itemid=85&lang=ennique identifier number.


15 HexID• Bits 26 to 85 are converted from binary to

hexadecimal.


C/S Beacon Coding

A Beacon Coding Guide is available at:

http://www.cospassarsat.org/index.php?op=com_content&view=article&id=189&Itemid=118&lang=en


Available C/S Beacon Message Protocols

– EPIRB = 10 protocols

– PLB = 4 protocols

– ELT = 12 protocols

– SSAS = 1 protocol


Country Codes

• MID or Country Codes are assigned by the International Telecommunications Union (ITU).

• US Country Codes: 366 is the preferred US Code, but 303, 338, 358, 367, 368, 369, 536 and 559 are available.

MID = Maritime Identification Code


Country Codes

• A full list of all the country codes is available to download at:

http://www.morrazo.org/baleadous/documentos/MMSI%20CODIGOS%20PAISES.pdf


C/S 406 MHz 406 Frequency Stability

• Frequency stability very important– C/S Beacon gets on frequency fast and

is super stable


406 MHz Detection Rangewith the USCG DF-430

Altitude (ft) Detection Range (nm)

25,000 133

22,500 129

20,000 124

17,500 119

15,000 113

12,500 106

10,000 99

7,500 88

5,000 76

2,500 57

1,500 23


C/S Beacon Self Test

• Battery Voltage Check

• Full Circuitry Check

• Test Data burst

• GPS acquisition Test (Self Locating)

• Not required to check remaining power available in the battery.


EPIRB

• C/S 406 MHz Maritime Satellite

• Emergency

• Position-Indicating

• RadioBeacon04/19/23 L. Yarbrough/D7CFVS

EPIRB Operational Requirements

• Strobe Light• Auxiliary Radio-Locating Device121.5 MHz, 25

mW, Warble, (US. and SOLAS requirement) • Lanyard – 5 to 8 meters• Battery – 48hrs of continuous operation• Buoyancy and Stability – float upright• Designed to prevent inadvertent activation


Types of Brackets

• Category 1 (Float Free)Automatic Release

between 4 to 13 ft.

EPIRB is transmitting when it gets to the surface

Hydrostatic release needs replacement every two years.


Type of Brackets

• Category 2(Non Float Free)Manual ReleaseWet sense deactivation

magnetNo Bracket carriage

requirement


Types of EPIRBs

• Class A & B 121.5MHz and 243 MHz only– Now illegal to use in the USA– No Satellite Detection

• 406 MHz and 121.5 EPIRB– Cat 1 and 2 brackets, Class 1 and 2 batteries

• 406 MHZ and 121.5 Self locating EPIRB– Cat 1 and 2 brackets, Class 1 and 2 batteries,

GPS interface or internal GPS


Class 1 and 2 Batteries

• Operating– Class 1 -40° to + 55° C– Class 2 -20° to + 55° C

• Stowage– Class 1 -50° to + 70° C– Class 2 -30° to + 70° C


Lanyard


Lanyard: 5 to 8 meters Orange/yellow color Not rot/deteriorate

Battery Replacement• Required at Expiration date or if EPIRB

activated for any reason besides test.

• Expiration of battery = ½ Useful Life.

• Useful Life = power for all required testing + 48 hrs operation.


EPIRB Operational Requirements

• Positive visual and/or audible indication that EPIRB is activated (strobe light flashing).

• Easily manually deployed, activate, and deactivated, and transferred to survival craft.

• Not be activated or deactivated by conditions encountered in maritime environment.


EPIRB Control

• Ready – EPIRB will be ON in the water unless in its bracket. Sometimes labeled “OFF”.

• ON – EPIRB operates regardless of location or orientation. Unconditional “ON” position. (Requires two physical actions)

• Test – Self-test Function.


EPIRB Switches


Prevention of Inadvertent Activation

• Must be fitted with means to prevent inadvertent activation and deactivation.

• Not automatically activate when water washes over while in bracket.

• Most EPIRBs use bracket with magnet to disable activation circuit.


EPIRB Deactivation

• Remove beacon from water and dry off or replace in bracket

• Move switch to OFF or Ready position

• Remove cover and disconnect battery


EPIRB Activation

• How– By definition it transmits:

• out of bracket and wet,

• by manual switch, in or out of bracket,

Or– Self test


EPIRB Activation

• What Happens;– Beacon starts transmitting its Unique

Hex ID in a 406 MHz digital message,

– 121.5 MHz homer with an audible warble,

– Strobe Light starts flashing.


Brackets

• Brackets – Cat 1


Brackets

• Brackets - Cat 1


Testing Bracket Magnet


A Compass provides simple detection on bracket magnet.

Bracket Water Testing


Questions?

[email protected]

(305) 415 6868


uscg/noaa sarsat conference 2011 epirb’s how they work

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