Developed as part of the National Emergency Services Curriculum Project How the Mission Starts ELT set off by plane crashing or EPIRB goes off when ship sinks or when either is accidentally set off ID: 1031204
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1. Electronic Direction FindingDeveloped as part of the National Emergency Services Curriculum Project
2. How the Mission StartsELT set off by plane crashing, or EPIRB goes off when ship sinks or when either is accidentally set off97 to 99 percent of all ELT missions are false alarmsSARSAT or COSPAS receives the signalThe satellite transmits the mirror locations of the target to a Local User Terminal (LUT)
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4. How the Mission Starts ContinuedThe LUT forwards the information to the Mission Control Center so that the appropriate Rescue Coordination Center can be notifiedAFRCC, at Langley AFB, calls the mission coordinator or designee who proceeds with the callout
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6. Rescue Coordination Centers (RCCs) Receive SARSAT Distress Alerts from the USMCC Coordinate the Rescue ResponseU.S. Coast Guard* Responsible for all Maritime Alerts *U.S. Air Force* Responsible for all Inland Alerts *
7. United States Cospas-Sarsat Program AdministrationInland SARMaritime SARResearch & DevelopmentSystem Operation
8. Distress Beacon FrequenciesPrimary:121.5 MHz, and its harmonics (243 MHz)243 MHz, military frequency406 MHz, next generation distress beacons transmitting location, tail number or boat identification, etc.Training:121.775 MHzRequired by FAA as of 31 January 1998121.6 MHz is no longer authorized for training
9. Frequency ChangeSATELLITE PROCESSING OF 121.5/243 MHz EMERGENCY BEACONS TO BE TERMINATED ON FEB. 1, 2009 Mariners, aviators, and individuals using emergency beacons will need to switch to those operating at 406 MHz if they want to be detected by satellites.
10. …it becomes “illegal for use” on Jan 1st, 2007!!!This is a new regulation under the recently issued FCC Title 47, Part 80 rules (August, 2003)Can no longer purchase a 121.5 MHz EPIRB as of Feb 1st, 2003Frequency Change Cont.
11. The Distress Alerting Satellite SystemThe Future of Cospas-Sarsat… 406 MHz “bent-pipe” repeaters on future GPS satellites Full compatibility with existing + future 406 MHz beacons Continued global detection and location: Greater than current Cospas-Sarsat accuracy Alert data downlink will continue to be freely available internationally Possible two-way return linkGPS Satellite
12. 2002 COSPAS-SARSAT Rescues 1,545 persons rescued in 365 SAR events worldwide - 1341 maritime rescues in 239 SAR events - 83 aviation rescues in 47 SAR events - 121 land rescues in 79 SAR events2002 U.S. SARSAT Rescues 171 persons rescued in 69 SAR events nationwide 133 maritime rescues in 64 SAR events 11 aviation rescues in 5 SAR events 27 land rescues in 18 SAR eventsSince 1982 over 15,000 lives rescued via Cospas-Sarsat! Nearly 5,000 in U.S. AOR’s alone! The Bottom Line…
13. Distress BeaconsThere are three types of beacons used to transmit distress signals:EPIRBs (for maritime use) ELTs (for aviation use)PLBs (used for land-based applications)
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18. What are you looking for?
19. Personal Locater BeaconsIn the United States, PLBs are now authorized for nationwide use. This authorization was granted by the FCC beginning July 1st, 2003.
20. L-Per ComponentsReceiver: the actual metal box, has 7 features:Dial: indicates signal strength or direction depending on whether in REC or DF modeMode switch: sets into DF, REC or OFF positionsFrequency selector: allows the selection of the frequencies possible depending on what is installed and the model
21. L-Per Components ContinuedSensitivity switch: a variable switch that adjusts the receiver's sensitivity. The closer to the target the less sensitivity is requiredVolume control: adjusts the audible signalSpeaker: emits the audible signalDial light switch: turns the dial light on for use in low light conditions
22. L-Per Receiver
23. MastThe two piece wooden vertical mast is joined in the middle by a bolt and wing nut, allowing the mast to be folded for storage or while the unit is carried through the woods. Make sure to hold the mast on both levels because the L-Per tends to be a knuckle-buster. L-Per Components ContinuedThe coaxial cable for connecting the radio to the antenna, and mounting screws for attaching the receiver to the mast are mounted to the mast.
24. L-Per Components ContinuedAntenna crossbarAntenna elements are attached to the crossbar, varying in size according to the frequency that you are searching on Wire leads connect the antenna elements together at the switchbox located in the middle of the crossbar. The antenna elements fold down parallel to the crossbar for storage or carrying through the wilderness.
25. Using the L-Per
26. L-Per in DF ModeDF mode measures equal strengths of signalNot completely accurate, but good enough!When needle is centered, ELT could be either directionNeedle always POINTS to the ELT (DF=Follow the needle)Use a TURN to TELL if the ELT is in front or behind you
27. DF = Follow the Needle
28. L-Per in REC ModeReceive Mode Measures Signal Strength onlySignal comes from the direction of the arrows on the antenna (to your left)
29. L-Per in REC Mode ContinuedUse it with multiple centers (more than 2) to verify strongest pathDuel ReflectionsThat’s most likely the true direction to the ELT
30. Using the Tracker DF Unit
31. Tracker Operating InstructionsUnfold antennae of the receiver unit, front antennae first then rear antennaeStart the receiver by pressing ON-button.When turning on the receiver, it will automatically select the international distress frequency (121.5 MHz), channel 1, and the green lights start blinking on the LED displayUse the CH button switch between the distress and practice frequency
32. Tracker Operating Instructions ContinuedBy Pressing the MAN button you can choose manual operation instead of automatic.The MAN light will be lit when this mode has been selectedReceiver sensitivity can be adjusted in the manual modeIn manual or automatic mode, the LED display reflects signal strength in the direction of the signal beacon
33. Sensitivity control when in manual mode accomplished by rotating wheelSignal strength indictorChannel indicator lightsManual mode indicator light and low battery indicator lightCH changes from channel 1 or 2 MAN switch alternates between automatic and manual sensitivity
34. Other UnitsThere are other companies that produce electronic direction finding units.
35. Body ShieldingA method of beating reflections at close rangeCan use L-PerRadio Shack JETSTREAM radio is better and CHEAP!Body blocks out the signalCalled a NULLNull should be at your BACK
36. Body Shielding ContinuedAt extremely close range, a 2m VHF radio un-squelched may workThis works ok when trying to figure out a particular aircraft on a flight line, it will probably not identify a particular hangar
37. Line of Sight TransmissionELTs are limited to Line of Sight propagation and reflectionsYou don’t always need to hear the ELTCarrier wave may be broadcasting with no audible sweep
38. What Else Can Affect An ELT Signal?Power lines Fence Line (signal can follow)Reflections off of obstaclesHangarsMoving TargetNot using the Equipment Properly - See Picture at Right What’s wrong with this?
39. Set Up the Equipment CompletelyOpen the Antennae Fully for use in the field
40. ReflectionsTo beat reflectionsCheck sensitivity oftenUse REC modeUsually strongest signal is not a reflectionUse the rubber ducky antenna when sensitivity is lowRe-trace your steps if necessary, going back to locations of strong signal strength
41. TriangulationDocumenting team movements is logical, and can allow the team to locate the distress beacon sooner
42. Triangulation ContinuedYou must be able to receive the signalCenter up DF unit on the signalTake the magnetic bearing (shoot an azimuth)Correct for magnetic variationEast is least, West is bestPlot your bearings (draw a line) on mapThe ELT should be where the lines cross!
43. Plot your Bearings
44. What information is needed for the IC?MakeModel and Model #ManufacturerLocation DescriptionApproximate location (Latitude & Longitude)OwnerTail Number or Boat Name and NumberTime Found and Time Shut-off
45. What information is needed for the IC? ContinuedSwitch Position on ELT or EPIRB: ON, OFF, or ARMManufacture DateBattery Expiration DateInformation which could indicate reason for accidental or justified activation of ELT or EPIRBNOTE: If you can’t get certain information, don’t worry, the AFRCC understands
46. Electronic Direction Finding TasksGround Team MembersO-0301: Determine Distress Beacon BearingO-0302: Locate a Distress BeaconGround Team LeadersO-0303: Deactivate a Distress BeaconO-0304: Triangulate on a Distress Beacon
47. QUESTIONS? THINK SAFETY!