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Equipment and SystemsLesson 1 of 2

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EQPS 001

Introduction to equipment and systems

CNS

CNS is communication, navigation and surveillance: one of the air navigation services (ATM 001). It splits into three areas.

ICAO Annex 10Aeronautical Telecommunications covers all three areas.
CNSCommunication, navigation and surveillance
COMCommunication
  • Fixed or mobileFixed: between ground stations. Mobile: with aircraft.
  • Voice or data
NAVNavigation
  • Ground-based systems
  • Satellite systems
  • Aircraft-based systems
SURSurveillance
  • Dependent or independentWho works out the aircraft's position.
  • Cooperative or non-cooperativeWhether the aircraft's equipment takes part.

Two ways to sort surveillance

Surveillance is sorted by two pairs: who works out the aircraft's position, and whether the aircraft's equipment takes part.

Who works out the position
DependentThe aircraftThe aircraft works out its own position and sends it.
vs
IndependentThe groundThe ground works out the aircraft's position.
Does the aircraft take part
CooperativeEquipment on boardThe aircraft's equipment takes part.
vs
Non-cooperativeNothing on boardNo equipment on board is needed.
PSRPrimary surveillance radarEcho off theaircraft itselfIndependentNon-cooperativeSSRSecondary surveillance radarReply from theaircraft's transponderIndependentCooperative
On both radars the ground works out the position. PSR needs nothing on board: the echo comes off the aircraft itself. SSR needs the aircraft's transponder to reply.

Primary radar (PSR) is the only non-cooperative surveillance.

The ATC system

The computer system at the working position. An air traffic control system has three main parts.

THE ATC SYSTEMRadarFlight plansRadar dataprocessing systemFlight plan dataprocessing systemUser interfaceThe operatorswork with it
Both processing systems feed the third part: the user interface, which the operators work with.

The course slide calls it the air traffic management system. It is the computer system at the working position, not ATM the service, which is ATFCM, ASM and ATS (ATM 001).

Reading material

Equipment and Systems

EQPS 001 Introduction to Equipment and Systems PowerPoint / PDF
EPN Group Training Document Equipment and Systems, chapter 1 Reading list, course material
International Civil Aviation Organization, Annex 10, Aeronautical Telecommunications, Volume III, Communication Systems, 2nd edition, 2007 Reference, paid
IATA, User Requirements for Air Traffic Services (URATS), Communications, Navigation and Surveillance (CNS) Technologies, 3rd edition, July 2017 Reference, free