Thursday, November 6, 2008

DISTRESS SIGNAL


AUTOMATIC DISTRESS SIGNAL UNIT


The radiotelegraphic distress signal consist of the group SOS, transmitted as a single signal in which the dashes are emphasized clearly from dots.
The radiotelephone distress signal consist of the word "MAYDAY" pronounced as the French expression "M'aider".
These distress signal indicate that a ship, aircraft or other vehicle is threatened by grave and imminent danger and request immediate assistance.

DISTRESS COMMUNICATIONS




The distress call shall have absolute priority over all transmission. All stations which hear it small immediately cease any transmission capable of interfering with the distress traffic and shall continue to listen on the frequency used for the emission of the distress call.
This shall not be addressed to a particular station and acknowledgement of receipt shall not be given before the distress message which follows it is sent.
The distress call and message shall be sent only on the authority of the master of the vessel or person responsible for the ship, aircraft or other vehicle carrying the mobile station or ship station.

OPERATIONAL BREVITY WORDS AND TERMINOLOGY

The following are two lists of operational brevity words and terms to provide common understanding and minimize radio transmissions while executing tactics described in this manual. This common understanding, however, is dependent on the following rules of engagement:

- These lists are not all inclusive.

- Use plain English when required.

- Words listed below should be used in lieu of words or phrases with similar definitions.

- When a flight lead makes directive calls, the wingman must respond with the directed action to the best of his ability.

- If the wingman uses a "directive" term/word, it is a request and the flight lead reserves the right to approve/deny the wingman's requested action.

Allied nations may have different meanings for some of the terms/words listed here (reference ACP 165). They are indicated by an asterisk (*) behind the term/word.

SECTION A: OPERATIONAL BREVITY WORDS

ABORT - Directive to cease action/attack/event/mission.

ACTION - Directive to initiate a briefed attack sequence or maneuver.

ALPHA CHECK - Request for bearing and range to described point.

ANCHOR - Orbit about a specific point; ground track flown by tanker. Information call indicates a turning engagement about a specific location.

ANGELS - Height of aircraft in thousands of feet.

APEX/ALAMO - Training term used to denote simulated launch of enemy, all-aspect radar missile.

APHID/ARCHER Training term used to denote simulated launch of enemy heat seeking missiles.

ARM/ARMED (Safe/Hot) - Select armament (safe/hot), or armament is safe/hot.

AS FRAGGED - Fighter, FAC, mission package, or agency will be performing exactly as stated by the air tasking order.

ASPECT - Request/comment regarding target aspect information.

ATTACK/ATTACKING() - Indicates air-to-surface attack on a specific ground target.

AUTHENTICATE() - To request or provide a response for a coded challenge.

AUTONOMOUS - Aircrew is operating without benefit of GCI/AWACS control.

BANDIT(Radar/Heat/Striker) - Known enemy aircraft and type ordnance capability, if known.

BASE (Number) - Reference number used to indicate such information as headings, altitudes, fuels, etc.

BEAM/BEAMER (Direction) - Aircraft maneuvering stabilized within 700 to 1100 aspect; generally given with cardinal directions: east, west, north, south.

BELLYCHECK - A momentary unloaded bank to check the blind side of a turning aircraft.

()BENT - Identified system inoperative.

BINGO - Prebriefed fuel state which is needed for recovery using prebriefed parameters.

BLIND - No visual contact with friendly aircraft; opposite of term "VISUAL."

BLOWTHROUGH - Directive/informational call that indicates aircraft will continue straight ahead at the merge and not turn with target/targets.

BOGEY - A radar/visual contact whose identity is unknown.

BOGEY DOPE/DOPE - Request for target information as briefed/available.

BONE - Term used to indicate the formation will remain in a Racetrack-type holding pattern (with all wingmen's tums into lead); exit formation must be specified by lead.

BOX - Groups/contacts/formations in a square or offset square.

BRACKET - Indicates geometry where aircraft will maneuver to a position on opposing sides either laterally or vertically from the target.

BREAK (Up/Down/Right/Left) - Directive to perform an immediate maximum performance turn in the indicated direction. Assumes a defensive situation.

BREVITY - Term used to denote radio frequency is becoming saturated/degraded and briefer transmissions must follow.

BROADCAST - Request/directive to switch to Broadcast Control.

BROKE LOCK - Loss of radar/IR lock-on (advisory).

BUDDY SPIKE (Position/Azimuth/Altitude) - Receiving friendly AI RWR.

BUGOUT (Direction)Separation from that particular engagement/attack; no intent to reengage.

BULLSEYE - An established reference point from which the position of an aircraft can be determined.

BUMP/BUMP-UP - A fly-up to acquire line of sight to the target or laser designation.

BUNT - A pushover maneuver.

BURNER - Directive to select/deselect afterburner.

BUZZER - Electronic communications jamming.

CAP/CAP(Location) - An orbit at a specified location. Establish a combat air patrol at (location).

CHAFF - Call indicating chaff has been detected or to deploy chaff.

CHAMPAGNE - An attack of three distinct groups with two in front and one behind. The leading two groups are attempting to bracket with the trailing third group flying up the middle.

CHATTERMARK - Begin using briefed radio procedures to counter comm jamming.

CHECK ( ) - A directive statement made to momentarily monitor (specified items/systems).No response is required if status is normal.

CHECK ( Left/ Right) - Turn ( ) degrees left/right and maintain new heading.

CHICKS - Friendly fighter aircraft.

CHRISTMAS TREE - Directive to briefly turn on exterior lights to enable visual acquisition.

CIRCLE (RIGHT/LEFT) - Flight-lead-directed defensive maneuver in which the flight establishes a circular holding pattern for mutual support.

CLEAN - No radar contacts; used to confirm a good battle damage check (i.e., no air-to-surface ordnance remaining on the wingman's aircraft).

CLEARED - Requested action is authorized (no engaged/support roles are assumed).

CLEARED DRY - Ordnance release not authorized.

CLEARED HOT - Ordnance release is authorized.

CLOSING - Bandit/bogey/target is getting closer in range.

COLD - In context; attack geometry will result in a pass or roll out behind the target; or, on a leg of the CAP pointed away from the anticipated threats. Air-to-surface, dry or no-ordnance attack.

COMEBACK (Left/Right) - Directive to reverse course.

COMEOFF (Left/Right/High/Low/Dry) - A directive to maneuver as indicated to either regain mutual support or to deconflict flight paths for an exchange of engaged and supporting roles. Implies both "visual" and "tally."

COMMITTED/COMMIT - Fighter intent to engage/intercept; weapons director (WD) continues to provide information.

CONTACT - Radar/IR contact at the stated position; should be in bearing, range, altitude (BRA), Bullseye, or geographic position format.

CONTINUE - Continue present maneuver; does not imply clearance to engage or expend ordnance.

COVER - Directive to assume briefed support position and responsibilities.

CRANK (Direction) - F-Pole maneuver; implies illuminating target at radar gimbal limits.

CROSS TURN/CROSS - A 1800 heading reversal by a flight where aircraft turn into each other.

CUTOFF - Request for, or directive to, intercept using cutoff geometry.

DEADEYE Informative call by an airborne laser designator indicating the laser is inoperative.

DEFENSIVE (Spike/Missle/SAM/Mud/AAA) - Aircraft is in a defensive position and maneuvering with reference to the stated condition. If no condition stated maneuvering is with respect to A/A threat.

DEPLOY - Directive for the flight to maneuver to briefed positioning.

DIVERT - Proceed to alternate mission/base.

DOLLY - Data link equipment

DRAG/DRAGGING (Direction) - Bogey/Bandit maneuvering to 60 degor less aspect.

ECHELON (Cardinaldirection) - Groups/contacts/formation with wingman displaced approximately 45 deg behind leader's wing line.

ELEMENT - Formation of two aircraft.

ENGAGED - Maneuvering with the intent of achieving a kill. If no additional information is provided (bearing, range, etc.), ENGAGED implies visual/radar acquisition of target

ESTIMATE - Using information available to provide data required, implies degradation.

EXTEND (Direction) Directive to gain energy and distance with the possible intent of reengaging.

EYEBALL - Fighter with primary visual identification responsibility.

FADED - Previous radar contact is lost

FAST - Target speed is estimated to be 600 knots ground mach 1 or greater.

FEET WET/DRY - Flying over water/land.

FENCE - Boundary separating hostile and friendly area.

FENCE CHECK - Set cockpit switches as appropriate.

FLANK/FLANKING - Target with a stable aspect of 120 deg. to 150 deg.

FLARES - Flares have been detected or directive to deploy flares.

FLASH (MODE) - Temporary activation of IFF transponder on desired mode/code.

FLOAT - Directive/informative to expand the formation laterally within visual limits to maintain a radar contact or prepare for a defensive response.

FOLLOW DOLLY - Follow data-link commands.

FOX - Air-to-air weapons employment.

FOX ONE - Simulated/actual launch of radar-guided missile.

FOX TWO - Simulated/actual launch of infrared-guided missile.

FOX THREE - Simulated/actual launch of AMRAAM/Phoenix missile.

FOX FOUR - Bomber gunner has simulated firing on a target.

FOX MIKE - VHF/FM radio.

FURBALL - A turning fight involving multiple aircraft.

GADGET - Fire control radar.

GIMBAL (Direction) - Radar target is approaching azimuth or elevation limits.

GO ACTIVE - Go to briefed Have Quick net.

GO SECURE - Activate secure voice communications.

GORILLA - Large force of indeterminable numbers and formation.

GREEN (Direction) - Direction determined to be clearest of enemy air-to-air activity.

GROUP - Radar target(s) within approximately 3 NM of each other.

GUN (Direction) - Visual acquisition of gunfire, AAA site, or AAA fire.

GUNS - An air-to-air or air-to-surface gunshot.

HARD (Direction) - High-G, energy sustaining turn.

HEAD - Target with an aspect of 160 deg. to 180 deg.

HEADS DOWN - Call to infom aircrew that leader/wingman is head-down in the cockpit and wingman/leader is responsible for clearing.

HEADS UP (Direction/Altitude) - Enemy/bogey got through; no kill.

HIGH - Target above 30,000 feet MSL.c

HIT - Radar return in search (A/A). Weapons impact within lethal distance (air-to-ground [A/G]).

HOLD DOWN - Directive to key transmitter for DF steer.

HOLDING HANDS - Aircraft in visual formation.

HOME PLATE - Home airfield.

HOOK (Left/Right) - Directive to perform an in-place 180 deg. turn.

HOT - In context; attack geometry will result in rollout in front of the target; or on a leg of the CAP pointing toward the anticipated threats (A/A). Ordnance employment authorized, expected, or completed (A/G).

HOTEL FOX - HF radio.

HOUND DOG - Informative call from support fighter to engaged fighter within visual arena that a shot opportunity exists. Implies tally/visual.

ID - Directive to intercept and identify the target; also aircrew ID accomplished, followed by type aircraft.

IN PLACE (Left, Right) - Perform indicated maneuver simultaneously.

JINK - Unpredictable maneuvers to negate a gun tracking solution.

JOKER - Fuel state above Bingo at which separation/bugout/event termination should begin.

JUDY - Aircrew has radar/visual contact on the correct target, has taken control of the intercept and only requires situation awareness information; weapons director (WD) will minimize radio transmissions.

KILL - Directive to commit on target with clearance to fire; in training, a fighter call to indicate kill criteria have been fulfilled.

LADDER - Three or more groups/contacts/formations in trail.

LINE ABREAST - Two groups/contacts/formations/aircraft side-by-side.

LOCKED (BRA/Direction) - Final radar lock-on; sort is not assumed

LOW - Target altitude below 10,000 feet AGL

MAGNUM - launch of AGM-88 HARM.

MARKING - leaving contrails or otherwise marking aircraft position.

MEDIUM - Target altitude between 10,000 feet AGL and 30,000 feet MSL.

MERGE(D) - Informative that friendlies and targets have arrived in the same visual arena.Call indicating radar returns have come together.

MICKEY - Have Quick time-of-day (TOD) signal.

MIDNIGHT - Informative call advising that command and control functions (GCI/AWACS) are no longer available.

MEL - Directive to select military power.

MUD (Direction-Type) - Indicates unknown RWR ground threat displayed; followed normally by clock position.

MUSIC - Electronic radar jamming. On AI radar, electronic deceptive jamming.

NAKED - No RWR indications. Opposite of term "spike".

NO JOY - Aircrew does not have visual contact with the target/bandit; opposite of term "TALLY."

NOTCH (Direction) - All-aspect missile defensive maneuver to place threat radar/missile near the beam.

OFF (Direction) - Informative call indicating attack is terminated and maneuvering to the indicated direction.

OFFSET (Direction) - Informative call indicating maneuver in a specified direction with reference to the target.

PACKAGE - Geographically isolated collection of groups/contacts/formations.

PADLOCKED - Informative call indicating aircrew cannot take eyes off an aircraft/ground target without risk of losing tally/visual.

PAINT - Friendly AAI/APX interrogation retum.

PARROT - IFF transponder.

PICTURE - Situation briefing which includes real-time information pertinent to a specific mission.

PIGEONS (Location) - Magnetic bearing and range to a specified point.

PITCH/PITCHBACK (Left/Right) - Directive call for fighter/flight to execute a nose-high heading reversal.

PLAYTIME - Amount of time aircraft can remain on station.

POINT - Directive for an element to turn towards each other either as a defensive response or to reestablish a mutually supportive formation.

POP - Starting climb for air-to-surface attack.

POPEYE - Flying in clouds or area of reduced visibility.

POSIT - Request for position; response normally in terms of a geographic landmark, or off a common reference point.

POST ATTACK (Direction) - WD transmission to indicate desired direction after completion of intercept/engagement.

POST HOLE - Rapid descending spiral.

POWER - Reminder to set the throttles appropriately considering the IR threat and desired energy state.

PRESS - Directive to continue the attack; mutual support will be maintained. Supportive role will be assumed.

PUMP - A briefed maneuver to stop closure on the threat or geographical boundry while maintaining situation awareness.

PURE - Call indicating pure pursuit is being used or directive call to go pure pursuit.

PUSH (Channel) - Go to designated frequency.

RAYGUN (Position/Azimuth/Altitude) - Radar lock-on to unknown aircraft. Request Buddy Spike/Naked reply.

RANCH HOUSE (Altitude) - Directive or informative indicating subject fighters will return to CAP.

REFERENCE (Direction) - Directive to assume stated heading.

RIFLE - AGM-65 launch.

ROGER - Indicates aircrew understands the radio transmission; does not indicate compliance or reaction.

RUMBA - Ownship maneuvering and ranging (OMAR), F-15 angle on ranging (AOR), F-16.

RUN/RUNNING (Direction) - Directive/Informative - Perform a defensive maneuver to place the threat radar/missile on the tail.

SAM (Direction) - Visual acquisition of a SAM or SAM launch. Should include position.

SANDWICHED - A situation where an aircraft/element finds themselves between opposing aircraft/elements.

SAUNTER - Fly at best endurance.

SEPARATE - Leaving a specific engagement; may or may not reenter.

SHACKLE - One weave; a single crossing of flight paths; maneuver to adjust/ regain formation parameters.

SHADOW - Follow indicated target.

SHIFT - Directive to illuminate second target with laser designator.

SHOOTER - Aircraft designated to employ ordnance.

SHOTGUN - Launch of antiradiation (SHRIKE) missile by Wild Weasel.

SICK - Described equipment is degraded.

SILENT - "GO SILENT" directive to initiate briefed EMCON procedures.

SKIP IT - Veto of fighter commit call; usually followed with further directions.

SLICE/SLICEBACK (Left/Right) - Directive to perform a high-G descending turn in the stated direction; usually 180 deg. turn.

SLOW - Target with ground speed of less than 300 kts.

SNAP SHOT - High-angle/high-LOS gun shot.

SNAP ( ) - An immediate vector (bearing and range) to the group described.

SORTED - Criteria have been met which ensure individual flight members have separate contacts; criteria can be met visually, electronically (radar) or both.

SPARKLE - Target marking by a gunship or FAC using incendiary rounds.

SPIKE - RWR indication of AT threat is displayed. Add clock position, and type threat (radar/heat) if able.

SPITTER (Direction) - An aircraft that has departed from the engagement.

SPLASH* - Target destroyed (air-to-air); weapons impact (air-to-ground).

SPLIT - Request to engage a threat; visual may not be maintained, requires flight lead acknowledgement (air-to-air). Also, directive to begin briefed maneuver/attack.

SPOOFING - Informative that voice deception is being employed.

SPOT - Informative that laser target designation is being received.

SQUAWK ( ) - Operate IFF as indicated or IFF is operating as indicated.

STACK - Two or more groups/contacts/formations with a high/low altitude separation in relation to each other.

STATUS - Request for an individual's tactical situation; response is normally "offensive," "defensive," or "neutral." May be suffixed by position and heading.

STERN - Request for, or directive to, intercept using stern geometry.

STINGER - Formation of two or more aircraft with a single in trail.

STRANGER - Unidentified traffic that is not a participant in the mission.

STRANGLE ( ) - Turn off equipment indicated.

STROBE - AI radar indications of noise radar jamming.

SUNRISE - Informative call that command and control functions are available from GCI/AWACS (opposite of MIDNIGHT).

SUPPORTING - The act of assisting the engaged fighter in killing the bandit while maintaining overall battle situation awareness.

SWITCH/SWITCHED - Indicates an attacker is changing from one aircraft to another.

TALLY - Sighting of a target/bandit; opposite of "NO JOY".

TARGET() - Specification of sort responsibility.

THREAT (Direction) - (GCI/AWACS) Informative that an untargeted bandit/bogey is within 10 NM of a friendly.

TIED - Positive radar contact with element/aircraft.

TRACK - A series of related contacts indicating direction of travel.

TRACKING - Stabilized gun solution.

TRAIL - Tactical formation of two or more aircraft following one another.

TRAILER - The last aircraft in a formation.

TRASHED - Informative call; missile in flight has been defeated.

TUMBLEWEED - Indicates limited situation awareness; no tally, no visual; a request for information.

UNIFORM - UHF/AM radio.

VIC - Three groups/contacts/formations with the single closest in range and an element in trail.

VICTOR - VHF/AM radio.

VISUAL - Sighting of a friendly aircraft; opposite of "BLIND."

WALL - Three or more groups/contacts/formations line abreast/side-side.

WEAVE - Continuous crossing of flight paths.

WEDGE - Tactical formation of two or more aircraft with the single in front and the other aircraft laterally displaced on either side behind the leader's wing line.

WEEDS - Indicates that aircraft are operating close to the surface.

() WELL - Described equipment is functioning properly.

WHAT LUCK - Request for results of mission/tasks.

WHAT STATE - Request for armament/fuel status; reported as follows: Gun = bullets remaining.

() Radar radar missiles remaining.

() Heat = heat missiles remaining.

() Fuel = pounds of fuel or time remaining.

WILCO - Will comply with received instructions.

WINCHESTER - No ordnance remaining.

WORDS - Mission-pertinent information.

WORKING - Wild Weasel is gathering EOB on a designated emitter.

ZIPPER - Acknowledge radio transmissions with two clicks of the mike button.

________________________________________________________

SECTION B: TERMS AND ABBREVIATIONS

A B C D E F G I J K L M N O P Q R S T U V W X Y Z

AAA - Antiaircraft Artillery.

AAI/APX - Air-to-Air Interrogator.

AAR - Air-to-Air Refueling.

AAW - Antiair Warfare.

ABCCC - Airborne Battlefield Command and Control Center.

ACA (Airspace Coordination Area) - A three-dimensional box in the sky defined by grid and/or land references and an altitude block (AGL). The intent of an ACA is to allow simultaneous attack of targets near each other by multiple fire support means, one of which is air. (See Army Field Manual 6-20).

ACBT - Air Combat Training; a general term which includes (D)BFM, (D)ACM, and (D)ACT.

ACC - Air Component Commander.

Acceleration Maneuver - An offensive or defensive maneuver, flown in the vertical plane, if possible, designed to increase or reduce distance from an object. A low Yo-Yo is an acceleration maneuver.

ACE - Airborne Command Element (AWACS/ABCCC).

ACM - Air Combat Maneuvering; training designed to achieve proficiency in element formation maneuvering and the coordinated application of BFM to achieve a simulated kill or effectively defend against one or more aircraft from a planned starting position.

ACO - Airspace Control Order. Document that details all approved airspace requests. The ACO will complement the ATO cycle and serve as the single planning document for airspace considerations.

ACT - Air Combat Tactics; training in the application of BFM and ACM skills to achieve a tactical air-to-air objective.

ADA - Air Defense Artillery.

ADIZ - Air Defense Identification Zone.

Adverse Yaw - The tendency of an aircraft to yaw away from the applied aileron while at high angles of attack.

Advisory Control - A mode of control in which the controlling agency has communications but no radar capability.

Aerodynamic Center - A point on the wing chord through which aircraft lift is directed. The aerodynamic center is usually defined as the point on the longitudinal axis of the airplane where the lift vector is centered. The distance between the aerodynamic center and the center of gravity is static margin, and is the major factor affecting the longitudinal static stability of the aircraft.

AFAC - Airborne Forward Air Controller.

AGL - Above Ground Level.

AGM - Air-to-Ground Missile.

AHC - Advanced or Aircraft Handling Characteristics; training designed to gain proficiency in and to exploit the flight envelope of the aircraft, consistent with operational and safety constraints.

AI - Air Interdiction/Air Intercept.

Airborne Order - A command authorization for tactical flight (departure time will be specified).

Air Refueling Time - Planned lapsed time from ARCT to drop off.

Air Refueling Track - A flight path designated for air refueling.

ALIC - Aircraft launcher interface computer.A

ALO - Air liaison officer.

Angle of Attack (AOA) - The angle between the mean chord line and the relative wind.

Angle Off - The angle formed by the extension of the longitudinal axes of two aircraft. Angle is measured from defender's 6 o'clock. Also called track crossing angle.

AOB - Air Order of Battle.

A-POLE - The distance from the launching aircraft to the target when the missile begins active terminal guidance.

Arcing - Flying a circular flight path which allows another aircraft the use of cutoff to gain closure.

ARCP - Air Refueling Control Point; the planned geographic point over which the receiver(s) arrive in the observation/precontact position with respect to the assigned tanker.

ARCT - Air Refueling Control Time; the planned time that the receiver and tanker will arrive over the ARCP-

ARIP - Air Refueling Initial Point; the planned point to enter the refueling track.

ARM - Antiradiation Missile.

Armament Safety Check - Action taken by an aircrew to review armament selection switches to preclude the inadvertent -launch/release of armament (Switches Safe).

ARS - Air Rescue Service.

ASM - Air-to-Surface Missile.

ASOC - Air Support Operations Center.

Aspect Angle - Angle between defender's longitudinal axis and the line of sight to the attacker.The angle is measured from defendees 6 o'clock. Attacker heading is irrelavent.

ASUW - Antisurface Warfare.

ASW - Antisubmarine Warfare.

ATO - Air Tasking Order (Frag)-Assigns air-to-air and air-to-surface targets, TOTS, and mission support information.

ATOC - Allied Tactical Operations Center (NATO).

Attack Restriction - Ingress, ordnance delivery, or egress restrictions depending on situation, i.e., threats, weather, terrain, ROE, etc.

AWACS - Airborne Warning and Control System.

BAI - Battlefield Air Interdiction.

BCE - Battlefield Coordination Element.

BDA - Bomb Damage Assessment. Summary of enemy surface targets destroyed or damaged.

BDZ - Base Defense Zone (NATO).

BFM - Basic fighter maneuvers- Training designed to apply aircraft handling skills to gain proficiency in recognizing and solving range, closure, aspect, angle off, and turning room problems in relation to another aircraft to either attain a position from which weapons may be employed, deny the adversary a position from which weapons may be launched, or defeat weapons employed by an adversary.

BRA - Bearing, range, and altitude of target

BREAK AWAY - Tanker/receiver call indicating immediate vertical and nose/tail separation between tanker and receiver is required.

Broadcast Control - A mode of control that passes target information by referencing a designated location, series of locations, or grid system.

Buffer Zone (BZ) - Airspace of defined dimension and adjacent to or near borders which may have special restrictions.

BVR - Beyond Visual Range.

CAG - Carrier Air Group.

CAP - Combat Air Patrol - Refers to either a specific phase of an air-to-air mission or the geographic location of the fighter's surveillance orbit during an air-to-air mission or to committing against a threat.

CAS - Close Air Support.

CBU - Cluster Bomb Unit.

CCA - Command and Control Agency.

C^2 - Command and Control.

C^3 - Command, Control, and Communications.

C^3CM - Command, Control, and Communications Countermeasures.

C^3I - Command, Control, Communications, and Intelligence.

CCT - Combat Control Team.

Cell - Two or more tankers/bombers flying in formation.

Center of Gravity (CG) - That point along the horizontal axis, fore and aft of which airplane weight is equal.

CFF - Composite force training or con formal fuel tank.

Chaff - Chaff is a passive form of electronic countermeasure used to deceive airborne or ground-based radar.

CL Max - Maximum Coefficient of Lift - Occurs at that angle of attack at which lift is maximum, thereby creating the maximum turn rate and maximum G loading for any condition of flight.

Clock Code - Description of position using the aircraft as a reference: the nose is 12 o'clock; the tail is 6 o'clock.

Close Control - A mode of control varying from providing vectors to providing complete assistance including altitude, speed, and heading.

Closure - Relative velocity of one aircraft in relation to another.

Collision Course - A flight path along which an aircraft is directed towards a point at which it will collide with another aircraft.

COMAO - Combined Air Operations.

Combat Separation (AWACS) - See classified description para 4-2(b)5. Combined - Multinational.

Comm Jamming - Attempt to interrupt communications.

Comparison Diagram - A chart comparing turn rate, radius, and excess power for two different aircraft. Also called energy/maneuvering (E/M) diagrams.

Compass Call - A C^3CM platform.

Composite Force Training - Scenarios employing multiple flights of aircraft, each under the direction of its own flight leader. Requires a minimum of three different types of aircraft in three different mission roles.

Condition of Vulnerability - A condition with the defender in the lethal envelope of the attacker's weapon system. It is possible for combatants to arrive at a mutual condition of vulnerability, particularly during a head-on pass.

Corner Velocity - The minimum airspeed at which the maximum allowable aircraft G can be generated.

CR - Control and Reporting.

CRC - Control and Reporting Center.

CRP - Control and Reporting Post.

CS - Antipersonnel chemical incapacitating agent (tear gas).

CSAR - Combat Search and Rescue.

DCA - Defensive counter air.

Defensive Maneuvering - Maneuvers designed to negate the attack/ordnance of a threat.

Defensive Spiral - A descending, accelerating dive using high G and continuous roll to negate an attack and gain lateral separation.

DLZ - Dynamic launch zone. A

DMPI - Desired mean point of impact-.

DR - Dead reckoning; navigation technique estimating position based on last known position, heading, speed, and time.

EC - Electronic Combat.

ECCM - Electronic counter-countermeasures.

ECM - Actions taken to prevent or reduce the effective use of the electro-magnetic spectrum, primarily through jamming and deception.

EID - Electronic Identification.

Element - A flight of two aircraft.

EMCON - Emission control. A

Engagement - Maneuvers by opposing aircraft attempting to achieve/prevent weapons firing positions.

EO - Electro-optical.

EOB - Electronic Order of Battle.

EON - AMRAAM Engagement Order Number.

EPA - Evasive Plan of Action.

E-Pole - The range from a threat aircraft that a drag must be accomplished to kinematically defeat any missile the bandit could have launched or is launching.

ETA - Estimated Time of arrival.

ETAC - Enlisted Terminal Attack Controller.

EW - Electronic Warfare/Early Warning.

FAC - Forward Air Controller.

FACP - Forward Air Control Post (radar station).

FCS - Fire Control System.

FEBA - Forward Edge of the Battle Area.

FLIR - Forward-looking infrared.

FLOT - Forward Line of Own Troops.

F-Pole - The distance from the launching aircraft to the target at missile impact.

Frag - Fragmentary Order (ATO).

FSCL - Fire Support Coordination Line.

GBU - Guided Bomb Unit.

GCI - Ground Controlled Intercept.

GLCM - Ground Launched Cruise Missile.

GOB - Ground Order of Battle.

GPS - Global positioning system.

HARM - High Speed Antiradiation Missile, AGM 88.

Have Quick - A UHF jam-resistant radio.

HCA - Heading Crossing Angle; the angle formed by the intersection of the fighter's present heading, and the target's present heading.

HIAC - HARM interface adaptor computer.

HIDACZ - High Density Airspace Control Zone.

High Angle (Snap) Shot - A gun shot made with a high track-crossing angle, normally attempted because a tracking shot was not possible or desired.

HIMAD - High- and Medium-Altitude Air Defense.

HIMEZ - High Missile Engagement Zone (NATO).

Hostile - A contact positively identified as enemy in accordance with (IAW) operational command ROE.

Hunter-Killer - Flight mix of F-4C; Wild Weasel and other aircraft employed in SEAD operations.

IADS - Integrated Air Defense System.

IFF/SIF - Identification Friend or Foe/Selective Identification Feature.

IMC - Instrument Meteorological Conditions.

Intercept - A phase of an air-to-air mission between the commit and engagement.

IR - Infrared.

IRCM - Infrared countermeasures.

JAAT - Joint Air Attack Team. Coordinated employment of attack helicopters and fightersA employed against enemy ground vehicles and personnel.

JFACC - Joint Force Air Component Commander.

JFC - Joint Force Commander.

Jinking - Aircraft maneuvers designed to change the flight path of the aircraft in all planes at random intervals (usually to negate a gun attack).

JMO(AIR) - Joint Maritime Operations (AIR).

Joint - US/Multi-Service.

Lag Pursuit - An attack geometry that will cause the attacker to fly behind the target.

LANTIRN - Low-altitude navigation and targeting, infrared for night.

Lateral (Pitch) Axis - A reference line running left and right through thecent er of gravity of an airplane.

LCC - Land Component Commander.

Lead Pursuit - An attack geometry that will cause the attacker to fly in front of the target.

Lethal Envelope - The envelope within which the parameters can be met for successful employment of a munition by a particular weapons system.

Line-of-Sight - A line from the pilot's eye to the object (usually target) being viewed.

Line of Sight Rate - An image's rate of movement across the canopy.

Line Up - Fighter briefing to FAC.

LGB - Laser-Guided Bomb.

LLTR - Low-Level Transit Route (NATO).

LOC - Line of Communication.

LOMEZ - Low Missile Engagement Zone (NATO).

Longitudinal (Roll) Axis - A reference line running fore and aft through the center of gravity of an airplane.

LORAN - Long-Range Navigation.

Lufberry - A circular, stagnated fight with no participant having an advantage.

Maneuverability - The ability to change direction and/or magnitude of the velocity vector.

Maverick - AGM-65. Terminally guided air-to-ground missile.

Maximum Coefficient of Lift - SeeCl Max.

Maximum Performance - The best possible performance without exceeding aircraft limitation is achieved.

MiG - Fighter aircraft designed and produced by the Mikoyan Gurevich Aircraft Bureau of the USSR.

Military Crest - A position along a ridge or hill two-thirds the distance from the base to the summit.

Mixed Force - The employment of a single flight of different types of aircraft, performing the same tactical role, under the direction of a single flight leader.

MIW - Mine Warfare.

MR/MS - Mission Ready/Mission Support.

MRU - Military Radar Unit.

MSA - Minimum Safe Altitude as defined in the FLIP General Planning Document.

MSL - Mean Sea Level.

Mutual Support - The coordinated efforts of two or more aircraft to provide combined firepower and survivability.

NCA - National Command Authority.

NCC - Naval Component Authority.

NAEW - NATO Airborne Early Warning.

NOB - Naval Order of Battle.

NORDO - No operative radio.

NUDET - Nuclear Detonation.

OCA - Offensive counterair.

Offensive Maneuvering - Maneuvers against an opponent to achieve weapons parameters.

Off-Station - Not in position.

On-Station - In position, ready for mission employment.

Ops Check - Periodic check of aircraft systems performed by the aircrew (including fuel) for safety of flight.

Pd - Probability of damage.

Pb - Probability of hit

PIREP - Pilot-reported weather conditions.

PITCH/PITCHBACK - A nose-high heading reversal to reposition as stated.

PJ - Pararescueman.

Pk - Probability of kill.

POPEYE - Flying in and out of clouds or area of reduced visibility.

Primary Force - The flight(s) that are being protected/escorted.

Ps - Specific excess power; Probability of survival.

Pure Pursuit - An attack geometry that will cause the attacker to fly directly at the target.

Ra - Maximum aerodynamic missile range.

Radial G - Effective "turning" G.

Rate of Turn - Rate of change of heading, normally measured in degrees per second.

RCC - Rescue Coordination Center.

RECCE - Reconnaissance.

RED (Risk Estimate Distances) - Reference MCM 3-1, Volume VIII. These distances are reasonable figures for employing weapons near friendly forces in combat and are not minimum safe distances for peacetime training use.

Relative Wind - The oncoming, instantaneous wind. For practical purposes, the direction of the relative wind is exactly opposite the flight path of the airplane.

Rmax - Maximum weapons range.

Rmin - Minimum weapons range.

ROCC - Regional Operations Control Center.

Rockeye (MK 20) - CBU with armor-piercing capability.

ROE - Rules of Engagement.

ROZ - Restricted Operating Zone (NATO). Temporary area restricted from fighter aircraft due to specialized operations.

RWR - Radar Warning Receiver.

SA - Situation Awareness/Surface Attack.

SAFE - Selected Area For Evasion.

SAG - Surface action group.

SAM - Surface-to-Air Missile.

Sandwich - A situation where the defending aircraft/element finds itself in between the attacking element.

Sanitize - Area clear of threats.

Scissors - A maneuver in which a series of hard turn reversals are executed in an attempt to achieve the offensive after an overshoot by an attacker.

Scramble - Takeoff as quickly as possible.

Scramble Order - Command authorization for tactical flight establishing an immediate departure time.

SEAD - Suppression of Enemy Air Defenses.

Semiactive - A system wherein the receiver uses radiations or reflections from the target which has been illuminated by an outside source.

Separation - Distance between an attacker and defender; can be lateral, longitudinal, or vertical.

SHORAD - Short Range Air Defense.

SHRIKE - AGM-45 antiradiation missile.

SLCM - Sea Launched Cruise Missile.

Slice/Sliceback - Maximum performance, nose-low turn.Usually performed at or near maneuver speed (corner velocity) with nose lowered sufficiently to maintain airspeed. This maneuver falls between a horizontal turn and a Split-S.

SLOC - Sea lines of Communication.

SOC - Sector Operations Center.

Sorting - Using any available information such as radar presentation, GCI information, etc., to determine which bandit to attack.

Specific Energy - Total mechanical energy per pound. Can be loosely described as an airplane's total energy resulting from airspeed and altitude.

Specific Excess Power - (PS) - A measure of an airplane's ability to gain or lose energy in terms of altitude, airspeed, or combination there of also called energy rate and expressed in feet per second or knots per second.

Split-Plane Maneuvering - Aircraft or elements maneuvering in relation to one another, but in different planes and/or altitudes.

STOP - Strategic Orbit Point.

STRATFOR - SAC advisors to Tactical Air Forces (formerly SAC ADVON).

STRIKE - An attack which is intended to inflict damage, seize, or destroy an objective (nuclear operations in NATO).

Suppressor - Aircraft designated to employ ordnance against defenses.

TAC-A (Tactical Air Coordinator-Airborne) - An airborne agency located far enough away from threats and jamming to provide a communications relay between fighters, FACS, and ground agencies. Typically aboard a FAC aircraft, ABCCC, or AWACS.

TACC - TacticalAir Control Center.

TACP - Tactical Air Control Party.

TACS - Tactical Air Control System.

Tactical Control - A mode of control similar to Close Control with regard to type information provided except vectors are not provided to the aircrew by the WC.

Tactical Separation - See classified description para 4-2d(l)(b)5.

Tactical Withdrawal - See classified description para 4-2d(l)(b)5.

TAF - Tactical Air Forces.

Target - Object being attacked.

TC - Transit Corridor (NATO). Air lanes established for transit in the rear area of the battle theater.

TFR - Terrain-following radar or reference to low altitudes pertaining to terrain-following radar.

TIC - Troops in Contact..

TL - Transit Level (NATO). Altitude blocks for deconfliction and identification of inbound/outbound air traffic.

TOF - Time of flight or actual time of flight. The time from weapon release to weapon impact

TOT - Time Over Target.

Total G - Indicated G.

TTA - AMRAAM time to active.

TTI - AMRAAM time to intercept.

Track Crossing Angle - See Angle Off.

TTP - Tactics, Techniques, and Procedures.

Vc - Closure between fighter and target expressed in knots, relative velocity.

Velocity Vector - A line representing the current direction and magnitude of the path of travel.

Vertical (Yaw) Axis - A reference line running up and down through the center of gravity of an airplane.

Vertical Rolling Scissors - A defensive descending rolling maneuver in the vertical plane executed in an attempt to achieve an offensive position on the attacker.

VID - Visual identification.

Vmax - Maximum possible speed for that altitude.

Vmaxp - Maximum sustainable speed for a given altitude.

VMC - Visual Meteorological Conditions.

Vmc -Practical maneuvering cruise speed.

Vmin - Slowest practical speed.

Vk - Target velocity.

WC - Weapons Controller.

WC^3 - Warning, Command, Control, and Communications.

WD - Weapons Director.

Weapons System - In regard to an-airplane, weapons system refers to the combination of airplane/aircrew/ordnance/ground crew/avionics, etc.

Wild Weasel - Dedicated radar defense suppression aircraft.

WILLY PETE - A white phosphorus smoke, rocket, grenade, or artillery round used to provide a ground reference. Can be employed as a bomb to provide a smokescreen.

WOC - Wing Operations Center.

RADIO VHF

Radio Use
The operator by law, must be familiar with and adhere to the provisions of the Federal Communications Commission. Although possession of the Rules and Regulations is not required, they may be obtained from the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.

Safety is the primary function of a radiotelephone aboard a boat.

At a minimum, you should:

1. MAINTAIN A WATCH while the radio is turned on, even though you are not communicating. Monitoring the Calling and Distress Channel 16 (2182 kHz SSB) is compulsory when the set is on and you are not communicating on another channel.
2. CHOOSE THE CORRECT CHANNEL when communicating either ship-to-ship or ship-to-shore.
3. LIMIT THE PRELIMINARY CALL to 30 seconds. If there is no answer, you must wait 2 minutes before repeating the call.
4. LIMIT SHIP-TO-SHIP CONVERSATIONS TO THREE MINUTES and the content to ship's business. Be considerate of others, they may want to use the line.
5. REMEMBER THAT PUBLIC CORRESPONDENCE HAS NO TIME LIMIT (private telephone calls) -The caller is paying the toll.
6. NEVER USE PROFANE OR OBSCENE LANGUAGE or transmit fraudulent messages. Penalties include fines up to $10,000 or imprisonment or both.
7. AVOID RADIO CHECKS as most are unnecessary. Do not call the US Coast Guard. If a check is really necessary, call a vessel that you know is listening. Radio checks are prohibited on Channel 16.

Logs: It is no longer necessary to keep a log of station operations. The operator may, however, keep a record of any distress or emergency traffic he hears or participates in along with a record of maintenance performed on the equipment.

Calling Procedure: The calling procedure has been developed in the interest of brevity. Calls are initiated on the Calling and Distress Frequency (Channel 16). If there is no traffic, begin by calling the name of the boat three times, followed by your boat name and its call sign.

Distress and Safety Calls
In an emergency as part of the marine safety and communication system, you have help on Channel 16 at your fingertips wherever you may be. Emergency situations can be categorized as distress, urgency and safety. The signals for these calls and their descriptions follow:

Distress: "MAYDAY, MAYDAY, MAYDAY." This is the International Distress Signal and is an imperative call for assistance. It is used only when a life or vessel is in immediate danger.

Urgency: "PAN-PAN, PAN-PAN, PAN-PAN" (PAHN PAHN). This in the International Urgency Signal and is used when a vessel or person is in some jeopardy of a degree less than would be indicated by Mayday.

Safety: "SECURITY, SECURITY, SECURITY" (SAY-CURE-IT-TAY). This is the International Safety Signal and is a message about some aspect of navigational safety or a weather warning.

Most boaters never have the need to make a distress call but all should be familiar with the proper procedure. WHEN YOU NEED IT THERE WILL NOT BE TIME TO LEARN IT. A "MAYDAY" situation is usually a hectic one, so having a Distress Communication Form partially completed and readily available is a great aid in making an organized distress call. The blanks on the form can be completed in compliance with your vessel data and posted near the radio telephone.

For Urgency (Pan pan) calls, a format similar to the "Mayday" signal can be used. Safety (Security) messages inform other boaters of abnormal situations relative to safe operation and are the lowest priority of the emergency situations.

Distress calls are initiated on Channel 16 because they should be heard by many boats, as well as the Coast Guard and other shore stations within range. If you receive a distress call, cease all transmission. All vessels having knowledge of distress traffic, and which cannot themselves assist, are forbidden to transmit on the frequency of the distress traffic. They should, however, listen and follow the situation until it is evident that assistance is being provided. Transmitting may resume after hearing an "all clear" (Silence Fini).

"Over and Out"
The most commonly misused procedure words are "Over and Out." "Over" means that you expect a reply. "Out" means you are finished and do not expect a reply. It is contradictory to say "Over and Out."

Radio Abuse
VHF marine radio is a vital communications link for the boating community and abuse of the radio seriously affects the safety of all boaters. There are FCC monitoring stations which, along with the Coast Guard, are alert for understandable language and correct operation of marine stations. Sophisticated equipment provides for tracking violators through "voice prints" of transmissions made on the radio.

Willful or repeat violators may receive a "Notice of Violation" citations, and be fined up to $2,000. The following will improve your radio communications:

* Marine Radio is not Citizens Band (CB), so watch your talk afloat. Phrases such as "Hey Good Buddy," "Bring That Back," "I Copy," and "That's a Big 10-4," are not only frowned upon by the authorities, but are illegal.
* Always use FCC call signals at the beginning and the end of all transmissions.
* Maintain radio watch on Channel 16, and use it only for emergency and calling purposes.
* Switch to one of the working channels for messages. Typically, these are 68, 69, 71, 72 and 78.
* Use low power (1 watt) whenever possible.

Wednesday, November 5, 2008

Citizens' Band (US unlicensed amateur radio)

Acronym Definition

CB Circuit Breaker
CB Citizens' Band (US unlicensed amateur radio)
CB Carte Blanche (credit card)
CB construction battalion (SEABEES) (US DoD)
CB Cambridge (postcode, United Kingdom)
CB Come-Back
CB Cambodia
CB Coldwell Banker
CB Chicago Bears
CB Citibank (Citigroup, Inc.)
CB Capacity Building
CB Children’s Bureau (US Department of Health and Human Services' Administration for Child)
CB Children's Bureau
CB Chris Brown
CB ChatterBox (motorcycle radio)
CB ClanBase (gaming)
CB Call Back
CB Cross-Border
CB Coffee Break
CB Crested Butte (Colorado)
CB Chairman of the Board
CB Crystal Ball (Utopia)
CB College Board
CB Chesapeake Bay (Maryland)
CB Chargeback (banking)
CB Charlie Brown
CB Cape Breton
CB Cowboy Bebop (anime)
CB Cartes Bancaires (French bank)
CB Chicago Bulls
CB Crossbow
CB Control Board
CB Conference Board
CB Certification Body
CB Crash Bandicoot (video game)
CB Cost/Benefit Analysis
CB Concert Band
CB Cumulonimbus (cloud formation)
CB Called Back
CB Chemical & Biological
CB Community Business
CB Code Block
CB Certification Bodies
CB Cheeseburger
CB Cell Block
CB Caribbean Beach (Disney Resort)
CB Competition Bureau
CB Chastity Belt
CB Cry Baby
CB Chemical Brothers (band)
CB Chessbase
CB Contrabass
CB Charles Barkley (basketball player)
CB Kampuchea (formerly Cambodia)
CB Chubut (Argentina Province, airline code)
CB Consumer Behavior (academic discipline within marketing)
CB Common Base (transistors)
CB Comment Back
CB Center Back (soccer position)
CB Clydesdale Bank (UK)
CB Corporation Bank (India)
CB Convertible Bond
CB Cell Broadcast (GSM)
CB Colorbar
CB Cinema Bizarre (German band)
CB Centre Back
CB Corner Back (football)
CB Cold Beer
CB Cool Breeze
CB Carte Bleu
CB Columbium (old name for Niobium)
CB Campobasso, Molise (Italian province)
CB Catch Basin (construction)
CB Code Breaker
CB Crushing Blow (Diablo II gaming)
CB Captain Beefheart (band)
CB Chauncey Billups (NBA Player)
CB Carlos Beltran (baseball player)
CB Christmas Break
CB Clostridium Botulinum
CB Code Blue
CB Communication Breakdown (song by Led Zeppelin)
CB Counter Balance
CB Conduction Band
CB Centralbibliotek
CB Certified Bookkeeper (American Institute of Professional Bookkeepers)
CB Captive Bred
CB Cotton Belt (railroad)
CB Crime Branch (Pakistan)
CB Carlos Boozer (NBA Player)
CB Charles Bukowski (writer)
CB Cluster Bomb
CB Control Bus
CB Collaborative Filtering
CB Carrier-Based
CB Coulomb Blockade
CB Cyanogen Bromide
CB Cloudbuster (Wilhelm Reich's rainmaker)
CB Central Booking (NYPD)
CB Celebrate Brooklyn (perfomance festival)
CB Coated Back (paper)
CB Cumulative Bulletin (Internal Revenue)
CB Causeway Bay (Hong Kong)
CB Constant Bandwidth
CB China Black (band)
CB Connector Box
CB Cliff Burton (Metallica bassist)
CB Center of Buoyancy
CB Cavalry Brigade
CB Charlie Bartlett (movie)
CB Counter Battery (Fire)
CB Chad Brock (country music artist)
CB Common Battery
CB Charlie Bravo
CB Composition B (explosive)
CB Large Cruiser (WW II ship type)
CB Central Battery
CB Block Coefficient (naval architecture)
CB Cumulo-Nimbus
CB Companion of the Bath (UK title)
CB Chemical and/or Biological
CB Compass Bearing
CB Confined to Barracks (UK)
CB ColdBlood (game)
CB Chain Break
CB Charged Bolt (gaming)
CB Clean Bench
CB Call Blocker
CB Crazy Bob
CB Center of Balance
CB Certificate of Birth
CB Crash Barrier (safety)
CB Confidence Bound
CB Crushbone (Everquest gaming)
CB Complementary-Bipolar (semiconductor process)
CB Center Bit (drilling industry)
CB Choice Band (gaming)
CB Catalyst Bed
CB Chief Baron (of the Court of Exchequer)
CB Carnage Blender (MMRPG/strategy game)
CB Cervicobrachial
CB Cobra Ball
CB Cloud Bottom
CB Certified Bodies
CB Cardiff Bus (travel company, Cardiff, Wales, UK)
CB Continuous Bubbler
CB Clan Beef (gaming clan)
CB Component Breakout
CB Coulomb-Born
CB Constant Budget
CB Cataclysmic Binary
CB COBRA BRASS
CB Chip Boundary
CB Certified Baker
CB Censor Bypass
CB Carlisle Band (Carlisle, PA)
CB Containment Breach
CB Collapsing Buffer
CB Circulation Blower
CB Common Bantu
CB Character's Birth
CB Casus Bellum (Latin: Justified Cause for War)
CB Chlorobromo-Methane
CB Conditional bias (radar rainfall)
CB Call Bearing
CB Compression Belt
CB Control/Containment Building
CB Coordinated Baseline
CB Air Post Semipostal (Scott Catalogue prefix; philately)
CB Collettore Benzina (automotive; fuel collector)
CB Crush Boat
CB Companion Commander of Bath

Sunday, November 2, 2008

AMATEUR RADIO



International Morse code today is most popular among amateur radio operators, where it is used as the pattern to key a transmitter on and off in the radio communications mode commonly referred to as "continuous wave" or "CW". The original amateur radio operators used Morse code exclusively, as voice-capable radio transmitters did not become commonly available until around 1920. Until 2003 the International Telecommunication Union (ITU) mandated Morse code proficiency as part of the amateur radio licensing procedure worldwide. However, the World Radiocommunication Conference of 2003 (WRC-03) made the Morse code requirement for amateur radio licensing optional.[2] Many countries subsequently removed the Morse requirement from their licence requirements.[3]

Until 1991, a demonstration of the ability to send and receive Morse code at 5 words per minute (WPM) was required to receive an amateur radio license for use in the United States from the Federal Communications Commission. Demonstration of this ability was still required for the privilege to use the HF bands. Until 2000, proficiency at the 20 WPM level was required to receive the highest level of amateur license (Extra Class); effective April 15, 2000, the FCC reduced the Extra Class requirement to 5 WPM.[4] Finally, effective February 23, 2007, the FCC eliminated the Morse code proficiency requirements for all amateur licenses.

While voice and data transmissions are limited to specific amateur radio bands under U.S. rules, CW is permitted on all amateur bands—LF, MF, HF, UHF, and VHF, with one notable exception being the 60 meter band in the US. In some countries, certain portions of the amateur radio bands are reserved for transmission of Morse code signals only. Because Morse transmissions employ an on-off keyed radio signal, it requires less complex transmission equipment than other forms of radio communication. Morse code also requires less signal bandwidth than voice communication, typically 100–150 Hz, compared to the roughly 2400 Hz used by single-sideband voice, although at a lower data rate. Morse code is received as a high-pitched audio tone, so transmissions are easier to copy than voice through the noise on congested frequencies, and it can be used in very high noise / low signal environments. The fact that the transmitted energy is concentrated into a very limited bandwidth makes it possible to use narrow receiver filters, which suppress or eliminate interference on nearby frequencies. The narrow signal bandwidth also takes advantage of the natural aural selectivity of the human brain, further enhancing weak signal readability. This efficiency makes CW extremely useful for DX (distance) transmissions, as well as for low-power transmissions (commonly called "QRP operators", from the Q-code for "reduce power"). There are several amateur clubs that require solid high speed copy, the highest of these has a standard of 60 WPM. The American Radio Relay League offers a code proficiency certification program that starts at 10 WPM.

The relatively limited speed at which Morse code can be sent led to the development of an extensive number of abbreviations to speed communication. These include prosigns and Q codes, plus a restricted standardized format for typical messages. This use of abbreviations also facilitates communication between operators who do not share a common language and thus would have great difficulty in communicating using voice modes.

Although the traditional telegraph key (straight key) is still used by many amateurs, the use of semi- and fully-automatic electronic keyers (known as "bugs") is prevalent today. Computer software is also frequently employed to produce and decode Morse code radio signals.

OTHER USES.

Operators skilled in Morse code can often understand ("copy") code in their heads at rates in excess of 40 WPM. International contests in code copying are still occasionally held. In July 1939 at a contest in Asheville in the United States Ted R. McElroy set a still-standing record for Morse copying, 75.2 WPM.[5] In his online book on high speed sending, William Pierpont N0HFF notes some operators may have passed 100 WPM. By this time they are "hearing" phrases and sentences rather than words. The fastest speed ever sent by a straight key was achieved in 1942 by Harry Turner W9YZE (d. 1992) who reached 35 WPM in a demonstration at a U.S. Army base.[6]

As of 2007 commercial radiotelegraph licenses are still being issued in the United States by the Federal Communications Commission. Designed for shipboard and coast station operators, they are awarded to applicants who pass written examinations on advanced radio theory and show 20 WPM code proficiency [this requirement is waived for "old" (20 WPM) Amateur Extra Class licensees]. However, since 1999 the use of satellite and very high frequency maritime communications systems (GMDSS) have essentially made them obsolete.

Radio navigation aids such as VORs and NDBs for aeronautical use broadcast identifying information in the form of Morse Code, though many VOR stations now also provide voice identification.

MORSE CODE




Morse code is a character encoding for transmitting telegraphic information, using standardized sequences of short and long elements to represent the letters, numerals, punctuation and special characters of a given message. The short and long elements can be formed by sounds, marks, or pulses, in on off keying and are commonly known as "dots" and "dashes" or "dits" and "dahs".

Originally created for Samuel Finley Breese Morse's electric telegraph in the early 1840s, Morse code was also extensively used for early radio communication beginning in the 1890s. For the first half of the twentieth century, the majority of high-speed international communication was conducted in Morse code, using telegraph lines, undersea cables, and radio circuits. However, the variable length of the Morse characters made it hard to adapt to automated circuits, so for most electronic communication it has been replaced by machine readable formats, such as Baudot code and ASCII.

The most popular current use of Morse code is by amateur radio operators, although it is no longer a requirement for amateur licensing in many countries. It also continues to be used for specialized purposes, including identification of navigational radio beacon and land mobile transmitters. Morse code is designed to be read by humans without a decoding device, making it useful for sending automated digital data in voice channels. For emergency signaling, Morse code can be sent by way of improvised sources that can be easily "keyed" on and off.

DEVELPOMENT AND HISTORY

Beginning in 1836, Samuel F. B. Morse and Alfred Vail developed an electric telegraph, which sent pulses of electrical current to control an electromagnet that was located at the receiving end of the telegraph wire. The technology available at the time made it impossible to print characters in a readable form, so the inventors had to devise an alternate means of communication. Beginning in 1837, William Cooke and Charles Wheatstone operated electric telegraphs in England, which also controlled electromagnets in the receivers; however, their systems used needle pointers that rotated to indicate the alphabetic characters being sent.

In contrast, Morse's and Vail's initial telegraph, which first went into operation in 1844, made indentations on a paper tape when an electrical current was transmitted. Morse's original telegraph receiver used a mechanical clockwork to move a paper tape. When an electrical current was received, an electromagnet engaged an armature that pushed a stylus onto the moving paper tape, making an indentation on the tape. When the current was interrupted, the electromagnet retracted the stylus, and that portion of the moving tape remained unmarked.

The Morse code was developed so that operators could translate the indentations marked on the paper tape into text messages. In his earliest code, Morse had planned to only transmit numerals, and use a dictionary to look up each word according to the number which had been sent. However, the code was soon expanded to include letters and special characters, so it could be used more generally. The shorter marks were called "dots", and the longer ones "dashes", and the letters most commonly used in the English language were assigned the shortest sequences.

In the original Morse telegraphs, the receiver's armature made a clicking noise as it moved into and out of position to mark the tape. Operators soon learned to translate the clicks directly into dots and dashes, making it unnecessary to use the paper tape. When Morse code was adapted to radio, the dots and dashes were sent as short and long pulses. It was later found that people become more proficient at receiving Morse code when it is taught as a language that is heard, instead of one read from a page.[1] To reflect the sound of Morse code, practitioners began to vocalise a dot as "dit", and a dash as "dah".

Morse code was an integral part of international aviation. Commercial and military pilots were required to be familiar with it, both for use with early communications systems and identification of navigational beacons which transmitted continuous three letter ID's in Morse code. As late as the 1990s, aeronautical charts listed the three letter ID of each airport in Morse and sectional charts still show the Morse signals for Vortac and NDB used for in flight navigation.

Morse code was also used as an international standard for maritime communication until 1999, when it was replaced by the Global Maritime Distress Safety System. When the French navy ceased using Morse code in 1997, the final message transmitted was "Calling all. This is our last cry before our eternal silence." See also: 500 kHz