a/c AircraftAAC Aeronautical Administrative CommunicationAAS Advanced Automation SystemAATC Advanced Automated Air Traffic ControlAATS Advanced Air Traffic SystemABI Advanced Boundary Information MessageACARS ARINC a/c Communications, Addressing and Reporting SystemACAS Airborne Collision Avoidance SystemACC Area Control CentreACCTS Aviation Coordination Committee for Telecommunication ServicesACF Area Control FacilityACG (Eurocontrol) ATS system Concept working GroupACR Approach Control RoomACT Activation Message (ICAO format)Ada Computer language/environmentADAPT ATS Data Acquisition Processing & Transfer (Swiss)ADCC Air Defence Control CentreADCE Audio Distribution & Control EquipmentADIS Airport Display Information SystemADLP Airborne Data Link ProcessorADOC Air Defence Operations CentreADP Aeroport de ParisADR Advisory RouteADR Automatic Data ReportingADREP Aircraft Accident Data ReportADS Automatic Dependent SurveillanceADT Actual/approved Departure TimeAEA Association of European AirlinesAECMA Association Europeenne de Constructeurs de Materiel AerospatialAEEC Airlines Electronic Engineering CommitteeAELE Association Europeenne de Libre Echange (=EFTA)AERA Automated En-Route ATCAES Aeronautical Earth StationAEW Airborne Early WarningAFC Aeronautical Frequency CommitteeAFIS Aerodrome Flight Information ServiceAFM Arrival Flow ManagerAFS Aeronautical Fixed ServiceAFTN Aeronautical Fixed Telecommunications NetworkAGARD Advisory Group for Aerospace R & DAGL Above Ground LevelAI Artificial IntelligenceAIC Aeronautical Information CircularAIP Aeronautical Information PublicationAIRCOM Airline Communication (datalink)AIS Aeronautical Information ServiceALFENS Automated Low Flying Entry Notification SystemALPA Airline Pilots AssociationAMS Aeronautical Mobile Service

AMSC American Mobile Satellite ConsortiumAMSC Automatic Message Switching CentreAMSL Above Mean Sea LevelAMSS Aeronautical Mobile Satellite ServiceANC Air Navigation CommissionANERC Advanced New En-Route CentreANFC Aeronautical Flight ChargingAO Aircraft Operator workstationAOA Aerodrome Owners AssociationAOC Airline Operational CommunicationsAOC Aerodrome Obstruction ChartAOCI Airport Operators Council InternationalAOPA Aircraft Owners and Pilots AssociationAPATSI Airport Air Traffic System InterfaceAPC Aeronautical Passenger CommunicationAPCI Application Protocol Control InformationAPDU Application Protocol Data UnitAPP Approach (control)APREPS Automatic Position REPorting SystemARC Aviation Review CommitteeARCS Airline Request Communications SystemARINC Aeronautical Radio IncorporatedARRCOS ARRival COordination System (BFS)ARSR Air Route Surveillance RadarARTAS Advanced Radar Tracker and ServerARTCC Air Route Traffic Control CentreARTS Automated Radar Terminal SystemASCAP Automatic SSR Code Assignment ProcedureASD Aircraft Situation DisplayASDE Airport Surface Detection EquipmentASECNA Assoc'n pour la Securite de la Navigation Aerienne (Africa)ASM Air Space ManagementASMI Airfield Surface Movement IndicatorASN Approach Sequence NumberASR Airfield Surveillance RadarASR Altitude Setting RegionASTA Airport Surface Traffic AutomationASTERIX All-purpose Structured Eurocontrol Radar Information ExchangeATA Actual Time of ArrivalATA Air Transport AssociationATC Air Traffic ControlATCA Air Traffic Control AssistantATCBI ATC Beacon InterrogationATCC Air Traffic Control CentreATCEU Air Traffic Control Evaluation UnitATCO Air Traffic Control OfficerATCRB ATC Radar Beacon SystemATCT ATC TowerATD Actual Time of Departure

ATDLVT Air Traffic Data Link Validation TeamATFM Air Traffic Flow ManagementATFMP Air Traffic Flow Management PositionATFMS Air Traffic Flow Management SystemATFMU Air Traffic Flow Management UnitATIS Automated Terminal Information ServiceATLAS Air Traffic Land-Air Systematm air traffic movementsATM Air Traffic ManagementATMOS Air Traffic Management Open SystemATMS Advanced Traffic Management SystemATN Aeronautical Telecommunications NetworkATN (CAA) Administrative Telephone NetworkATNPA ATN Protocol ArchitectureATO Actual Time of OverflightATOTN Air Traffic Operational Telephone NetworkATS Air Traffic ServicesATSU Air Traffic Service UnitATZ Aerodrome Traffic ZoneAUS Airspace Utilisation SectionAVPAC Aviation VHF Packet Communications (ARINC)AWP Aviation Weather ProcessorBATA British Air Transport AssociationBAUA British Aviation Users AssociationBFS Bundesanstalt Fur FlugsicherungBRITE Bright Radar Indicator Tower EquipmentBRITE Basic Research in Industrial Technologies for EuropeCA Conflict AlertCAA Civil Aviation AuthorityCAAFU Civil Aviation Authority /Flying Unit/MistakeCAATS Canadian Automated Air Traffic SystemCADIN Canadian Aeronautical Digital NetworkCAG Circulation Aerienne GeneraleCANAC Computer Assisted National ATC Centre (Belgium)CAPSIN Civil Aviation Packet Switched Integrated NetworkCAS Collision Avoidance SystemCASE Computer Aided Systems EngineeringCASOR Controlled/Civil AirSpace Operations RoomCASP Canadian Air Space PlanCAT CategoryCAT Clear Air TurbulenceCATC College of Air Traffic ControlCATSIM Civil Aviation Training SimulatorCAUTRA Coordination AUtomatique du Trafic AerienneCAVOK Ceiling and Visibility OKCC Computer ComplexCCD Cursor Control DeviceCCDB Code/Callsign Data BaseCCDS Code/Callsign Distribution System

CCF Central Control FunctionCCIR Consultative Committee for International RadioCCITT International Telegraph & Telephone Consultative CommitteeCCS Central Computer SystemCCTV Closed Circuit TelevisionCDB Central Data BaseCDBS Central Data Base SystemCDIS CCF Data Information SystemCEAC Committee for European Airspace CoordinationCEAC Conference de l'Aviation Civile Europeenne (=ECAC)CENA Centre d'Etudes de la Navigation AerienneCEPT Conference Europeenne des Administrations des PTTCERD Computer Entry and Readout DeviceCEU Central Executive Unit (FAA)CFCF Central Flow Control FacilityCFEP Communications Front End ProcessorCFL Cleared Flight LevelCFMU Central Flow Management UnitCFWSU Central Flow Weather Service UnitCHG Change Message (ICAO Format)CHI Computer-Human InterfaceCIDIN Common ICAO Data Interchange NetworkCIS Cooperative Independent SurveillanceCMS Common Modulator SimulatorCMTO Central ATFM OrganisationCMTP Common Medium Term PlanCNL Cancellation MessageCNS Communications, Navigation & SurveillanceCOCESNA Corporacion Centro Americano de Servicios Navegacion AereaCOMPAS Computer Orientated Metering Planning & AdvisoryCONUS Continental, Contiguous United StatesCOPS Common Operational Performance SpecificationsCOPS-I COPS InternationalCOPS-N COPS NucleusCORTA Cellule d'Organisation et de Regulation du Trafic AerienneCP Conflict PredictionCPR Conflict Prediction and ResolutionCRC Control and Reporting CentreCRCO Central Route Charging OfficeCRNA Centre Regional de la Navigation AerienneCRT Cathode Ray TubeCSC Chief Sector ControllerCTA Control AreaCTA Controle du Trafic Aerienne (=ATC)CTB Control Tower BuildingCTE College of Telecommunications EngineeringCTMO Centralised Traffic Management (ATFM) OrganisationCTS Central Time SourceCWP Controller Working Position

CWP Central Weather ProcessorCWP-Unit Design Unit of CWP modular architectureCZ Control ZoneD&D Distress and DiversionDAKOS DatenkommunicationssystemDARC Direct Access Weather ChannelDBC Data Bank COMECON (Eastern Europe)DBE Data Bank Europe (Western)DBMS Data Base Management SystemDCTS Data Communications Terminal SystemDCX Digital Communications ExchangeDEPCOS Departure Coordination SystemDEPS Airfield DEParture information SystemDFM Departure Flow ManagementDFR Departure Flow RegulatorDFTI Distance From Threshold IndicatorDFVLR Deutsche Forschungs und Versuchanstalt fur Luft und RaumfahrtDGAC Direccion General de Aviacion Civil (Spain)DGAC Direction Generale de l'Aviation CivileDIU Data Input UnitDLR Deutsche Versuchsanstalt fuer Luft und RaumfahrtDM Departure MessageDME Distance Measuring EquipmentDNA Direction de la Navigation AerienneDORA Directorate of Operational Research & AnalysisDP Data ProcessingDRC Data Rate ControlDSI Delivered Source InstructionsDUEV Datenuebertragungs und VermittlungssytemDVI Direct Voice InputDVOR Doppler Vhf Omnidirectional RangingE&S Executive and SupportEANPG (ICAO) European Air Navigation Planning GroupEAS Equivalent Air SpeedEASIE Enhanced ATM and Mode S Implementation in EuropeEAT Expected Approach Time (used in Arrival Flow Management)EATCHIP European ATC Harmonisation and Integration ProjectEATCOS European Air Traffic COntrol SystemECAC European Civil Aviation ConferenceECMA European Computer Manufacturers AssociationEDD Electronic Data DisplayEDDUS Electronic Data Display & Update SystemEEC Eurocontrol Experimental CentreEEC European Economic CommunityEFAS En-route Flight Advisory SystemEFIS Electronic Flight Instrumentation SystemEFMS Experimental Flight Management SystemEFTA European Free Trade AreaEGATS European Guild of Air Traffic Services

EITIRT European Information Technology Industry Round Table (ESPRIT)ELISA Elaboration des Informations de la Situation AerienneEM ElectromagneticENAC Ecole Nationale de l'Aviation CivileENB Engineering Note BookENS European Nervous SystemEQUATOR Environment for Qualitative Temporal Reckoning (ATFM)ERCC En-Route Control CentreES End SystemESA Electronically Scanned ArrayESA European Space AgencyESPRIT European Strategic Programme for Research and ITESSI European Software System InitiativeEST Estimate Message (ICAO Format)ETA Estimated Time of ArrivalETD Estimated Time of DepartureETE Estimated Time En-RouteETO Estimated Time of OverflightEURAM European Research on Advanced MaterialsEURET programme Europeen de Recherche dans les TransportsEUROCAE European Organisation for Civil Aviation ElectronicsEUROMART European Measures for Aeronautical Research and Technology.FAA Federal Aviation AuthorityFANS (ICAO) Future Air Navigation SystemFANSTIC Future ATS and New Systems Impact on CockpitFCC Flight Control CentreFCC Federal Communications CommissionFDB Full Data BlockFDDI Fibre/Fiber(US) Distributed Data InterfaceFDIO Flight Data I/OFDP Flight Data ProcessingFDPS Flight Data Processing SystemFEATS Future European ATS System Concept GroupFEP Front End ProcessorFIC Flight Information CentreFIR Flight Information RegionFIS Flight Information ServiceFIW Flight Plan Input WorkstationFL Flight LevelFLOE Flexible Operating EnvironmentFMECA Failure Modes, Effects & Criticality AnalysisFMP Flow Management PositionFMS Flight Management SystemFMU Flow Management UnitFPL Flight Plan or Flight Plan MessageFPPS Flight Plan Processing SystemFPS Flight Progress StripFS Functional SpecificationFSC Flight Scheduling & Coordination

FSP Flight Strip PrinterFSPS Flight Strip Printing SystemFSS Fixed Satellite ServicesGARTEUR Group on Aeronautical Research & Technology in EuropeGAT General Aviation TrafficGCA Ground Controlled ApproachGCAS Ground-based Collision Avoidance SystemGCTA Gestion des Courants de Trafic Aerien (= ATFM)GDLP Ground Data Link ProcessorGEC General Electric CompanyGEPNA Groupe Europeen de Planification de la Nav'n Aerienne (=EANPG)GERAC Groupe Europeenne Regionale AFTN/AFS CoordinationGES Ground Earth StationGLONASS Global Navigation Satellite SystemGMC Ground Movement ControlGMR Ground Movement RadarGMT Greenwich Mean TimeGNSS Global Navigation Satellite SystemGOES Geostationary Operational Environment SatelliteGPS Global Positioning by SatelliteGRANAS Global Radio Navigation SystemGS Ground SpeedGSTDN Ground Satellite Tracking and Data NetworkHADAMARDAda multiradar tracking algorithm (STNA)HCI Human-Computer InterfaceHCS Host Computer SystemHDG HeadingHF High FrequencyHIWAS Hazardous In-flight Weather Advisory ServiceHMI Human-Machine InterfaceHUFIT Human Factors in Information Technology (ESPRIT)HUPER HUman PERformance (ICAO committee)IACA International Air Charter AssociationIACA International Air Charter AssociationIAS Indicated Air SpeedIATA International Association of Travel AgentsIBCN Integrated Broadband Communications NetworkICAA International Civil Airports AssociationICAO International Civil Aviation OrganisationICCAIA International Co-ordinating Council of Aerospace Industry

AssociationsICNS Integrated Communications, Navigation and SurveillanceICS Independent Cooperative Surveillance (= SSR)ID IdentityIDB Integrated Data BaseIFALPA International Federation of Airline Pilots' AssociationsIFATCA International Federation of Air Traffic Controllers' AssociationsIFF Identification Friend or FoeIFPL Initial Flight Plan

IFPS Initial Flight Data Processing SystemIFPS Integrated Flight Plan ProcessingIFR Instrument Flight RulesIKBS Intelligent Knowledge-Based SystemsILS Integrated Logistic SupportILS Instrument Landing SystemIMAGE Instrument Macroscopique d'Aide a la Gestion de l'EspaceIMC Instrument Meteorological ConditionsINERC Initial New En-Route CentreINMARSAT International Maritime SatelliteINS Inertial Navigation SystemsINTELSAT International Telecommunications Satellite OrganisationINTNET Integrated NetworkIP Identification of Position (Military SPI)IPL Initial Program LoadIRIS Independent Radar Investigation SystemIRP Initial Reference PointIRS Inertial Reference SystemIRVR Instrumented Runway Visual RangeIS Independent SurveillanceISA Inbound Slot AllocatorISA International Standard AtmosphereISDN Integrated Service Digital NetworkISO International Standards OrganisationISSS Initial Sector Suite Sub-SystemIST Inbound Slot TimeIT Information TechnologyITT Invitation to TenderITU International Telecommunications UnionIUKADGE Improved UKADGEJACOLA Joint Airports Committee of Local AuthoritiesJAS Joint Airmiss SectionJATCRU Joint Air Traffic Control Radar UnitJAWG Joint Airmiss Working GroupKARLDAP Karlsruhe Automated Data ProcessingKBS Knowledge-Based SystemKDS Keyboard Display Systemkt Knot (nm per hour)LAM Logical Acknowledgement MessageLAN Local Area NetworkLARS Lower Airspace Radar ServiceLAS Lower AirspaceLATCC London Air Traffic Control CentreLATFMU London ATFMULDB Limited Data BlockLF Low FrequencyLJAO London (TMA) Joint (Military/Civil) Area OrganisationLLWAS Low Level Windshear Alert SystemLORAN Long Range Navigation System

LOS Line of SightLPATS Lightning Position and Tracking SystemLRNZ Luftraumnutzurzentrale (German ATFMU)LRRS Long Range Radar StationLRU Line/Lowest Replaceable UnitLSA Logistic Support AnalysisLSP Local System ProcessLTA Local Track Averaging (type of Multi-radar Tracking)LTMA London Terminal Manoeuvring AreaLVA Large Vertical Aperture (usually of SSR Antenna)MA Minimum AltitudeMADAP Maastricht Automated Data ProcessingMAESTRO Moyen d'Aide à l'Ecoulement Séquencé du Trafic avec Recherche d'OptimisationMAESTRO Means to Aid Expedition & Sequencing of Traffic with Research of OptimisationMAFALDA Maquette d'Analyse Fonctionnement d'Applications Liaison de Données Air/SolMALSR Med Intensity Approach Lighting System + Runway Alignment LightsMAP Missed Approach PointMARETS Military Airfield Remote Entry Terminal SystemMARS MET/AIS Retrieval SystemMASOR Middle/Military Airspace Operations RoomMAST Multi-Aircraft Simulation TerminalMATZ Military Air Traffic ZonesMDR Minimum Detectable RangeMETARS Aerodrome Met. ReportsMF Medium FrequencyMIDACS Microprocessor Data Acquisition SystemMIDAS Multisensor Integration and Data Fusion System (ESPRIT)MIPS Million Instructions Per SecondMLS Microwave Landing SystemMMI Man-Machine InterfaceMMIIU MMI Integration UnitMOPS Minimum Operational Performance StandardsMOTNE Meteorological Operational Telecommunications NetworkMRDV Multi-Radar Data Processing (BFS)MRSA Mandatory Radar Service AreaMRSL Marconi Radar Systems LimitedMRT Multi-Radar TrackingMSAW Minimum Safe Altitude WarningMSL Mean Sea LevelMSRCE Multicarrier Station Remote Control EquipmentMSS Mobile Satellite ServiceMTA Military Training AreaMTI Moving Target IndicationNADIN National Airspace Data Interchange NetworkNAR North Atlantic Route

NARIC Navigational Aids Remote Interrogation & ControlNAS National Airspace SystemNASA National Aeronautics and Space AdministrationNASP National Airspace System PlanNATS National Air Traffic ServicesNAVAID Navigational AidNAVSTAR Navigational Satellite System (=GPS)NBAA National Business Aircraft AssociationNDB Non-Directional BeaconNERC New En-Route CentreNEXRAD Next Generation Weather RadarNLR National Aerospace Laboratory (NL)nm Nautical MileNMS Network Management SystemNOAA National Oceanic and Atmospheric AdministrationNODE NATS Operational Display EquipmentNOTAM NOtice To AirMenNSAP Network Service Access PointNTSB National Transportation Safety Board (US)OACC Oceanic Air Traffic Control CentreOAG Official Airline GuideOAT Operational Air Traffic servicesOCA Oceanic Control AreaODAPS Oceanic Display and Planning SystemODID Operational Data Input DisplayOJT On-the-Job TrainingOLDI On-Line Data InterchangeORCAM Originating Region Code Allocation MethodORS Operational Requirements SpecificationOSI Open Systems Interconnect(ion)OTN Operational Telephone EquipmentOTS Organised Track Structure (North Atlantic)PABX Private Automatic (Board) ExchangePACTAS Predictive Approach Control Tactical Advisor SystemPAM Peripheral Adaptor ModulePAPI Precision Approach Path IndicatorPAR Precision Approach RadarPC Personal ComputerPCB Printed Circuit BoardPCMT Plan Commun a Moyen Terme (= CMTP)PE Permanent EchoPEGASUS Pan European Ground/Air Single Unified SystemPEX PHIGS (qv) Extension to X-WindowsPFD Planned Flight DataPHARE Programme for Harmonisation of ATM Research in EurocontrolPHIDIAS PeriPHerique Integre de DIalogue et d'ASsistancePHIGS Programmers' Hierarchical Interactive Graphics SystemPOSIX Portable Operating System Interface for Computer EnvironmentsPPI Plan Position Indicator

PRDDS PRDS Development SystemPRDS Processed Radar Display SystemPREVI French ATFMSPRF Pulse Repetition FrequencyPRODAT PROSAT Data Link ExperimentPROSAT Promotional SatellitePSDN Public Switched Data NetworkPSN Public/Packet Switched NetworkPSR Primary Surveillance RadarPSTN Packet Switched Telecommunications NetworkPVD Plan View DisplayPWG Planning Working GroupQDM Magnetic Heading to reach a particular pointQDR Magnetic heading to track away from a particular pointQFE Barometric Pressure at Runway ThresholdQNH Barometric Pressure at sea levelQOS Quality of Service (of the ATN)QSY Change Radio FrequencyQTE True bearing from a point to an aircraft.QWERTY Keyboard with standard layoutR&D Research and DevelopmentRADAR Radio Detection And RangingRADNET Radar Data Interchange NetworkRAE Royal Aircraft EstablishmentRAF Royal Air ForceRAIS Rapid Access Information SystemRAMP Radar Modernisation Project (Canada)RCM Radar Counter MeasuresRCMS Remote Control and Monitoring SystemRDF Radio Direction FinderRDIF Radar Data Interchange FormatRDP Radar Data ProcessingRDPDS Radar Data Processing and Display SystemRDPS Radar Data Processing SystemRENAR Reseau de la Navigation AerienneREP Reporting PointRISC Reduced Instruction Set ComputerRMCDE Radar Message Conversion & Distribution EquipmentRNAV Area NavigationRNIS Reseaux Numeriques a Integration de Services (= ISDN)RNPC Required Navigation Performance CapabilityROC Rate of ClimbROD Rate of DescentROP Runway Observation PostRP Radar ProcessorRPL Repetitive Flight PlanRR Range RingsRSCMS Radar Station Control & Monitoring SystemRSFTA Reseau du Service Fixe de Telecommunications Aeronautiques

RSRE Royal Signals & Radar EstablishmentRT Radio TelephonyRTCA Radio Technical Commission for AeronauticsRTQC Real Time Quality ControlRVR Runway Visual RangeRWY RunwaySAR Search & RescueSARP Standards and Recommended PractisesSATCOM Satellite CommunicationSBAC Society of British Aircraft ConstructorsScATCC Scottish Air Traffic Control CentreScOATCC Scottish and Oceanic Air Traffic Control CentreSDD Situation Data DisplaySELCAL Selective CallingSFDS System Functional Defining SpecificationSHF Super High FrequencySICASP SSR Improvement and Collision Avoidance System PanelSID Standard Instrument DepartureSIDE Sector Input & Display EquipmentSIGMET Significant Meteorological InformationSIR Serveur Information RadarSIRS Support Information Retrieval SystemSITA Societe Internationale de Telecommunications AeronautiquesSLAP Slot Allocation ProcedureSMR Surface Movement RadarSNOTAM Snow NOTAMSOC Sector Operations CentreSOTA South Atlantic Transition AreaSPI Special Position Indication (Civil IP)SPL System PlanSRA Special Rules AreaSRA Surveillance Radar ApproachSRG Safety Regulation GroupSRT Single Radar TrackingSRZ Special Rules ZoneSSCC System Support Computer ComplexSSR Secondary Surveillance RadarSST SuperSonic TransportSTAR Standard Arrival RouteSTAR Systeme de Traitement des Archives et RedevancesSTCA Short Term Conflict AlertSTNA Service Technique de la Navigation AerienneSTOL Short Take Off and LandingSTP Software Through PicturesSTP Sector Transit PlanSTPV Systeme de Traitement Plans de Vol (= FPP)STR Systeme de Traitement Radar (= RDP)SUA Special Use Airspace System (Germany)SVFR Special Visual Flight Rules

TA Traffic AlertTACAN Tactical Air Navigation SystemTAF Aerodrome ForecastsTAS True Air SpeedTATCA Terminal ATC AutomationTBA To Be AdvisedTCA Terminal Control AreaTCAS Traffic Alert and Collision Avoidance SystemTCC Traffic Control CentreTCCC Tower Control Computer ComplexTCSDG Terminal Control System Development GroupTEE Telecommunications Engineering EstablishmentTMA Terminal Manoeuvring AreaTMACC Terminal Manoeuvring Area Control CentreTMAR TMA surveillance RadarTMHT True Multi-Head TrackingTMRT True Multi-Radar TrackingTMS Traffic Management SystemTMU Traffic Management UnitTOS Traffic Orientation SchemeTRA Temporary Reserved AreaTRACON Terminal Radar Approach ControlTRANSPAC Transmission par PaquetsTRSB Time Reference Scanning BeamTSC Transportation System Center (US DOT)TWR Control TowerTWY TaxiwayUACC Upper Airspace Control CentreUAR Upper Air RouteUAS Upper AirspaceUHF Ultra High FrequencyUIMS User Interface Management SystemUIR Upper Information RegionUKAATS United Kingdom Advanced Air Traffic SystemUKADGE United Kingdom Air Defence Ground EnvironmentUKOOA UK Offshore Operators' AssociationVASI Visual Approach Slope IndicatorVCR Visual Control RoomVDU Visual Display UnitVFOP Visual Flight Operations PanelVFR Visual Flight RulesVHF Very High FrequencyVLF Very Low FrequencyVMC Visual Meteorological ConditionsVME Versa-Module (Euro-card)VOLMET Broadcast Meteorological informationVOR VHF Omnidirectional RangeVORTAC VOR + TACAN collocatedWAFS World Area Forecast System

WAN Wide Area NetworkWARC World Administrative Radio ConferenceWATTC World Administrative Telegraph & Telephone ConferenceWGS World Geodetic SystemWMO World Meteorological OrganisationWP Workstation ProcessorWS WorkstationWX WeatherZKSD Zentralen Kontrollstreindruck (Strip Printing System)ZOC Zone of Convergence