Lecture 7 Radio Detection And Ranging (RADAR)7讲无线电探测和测距（雷达）

Lecture5

RADAR

Part1OutlinesofLectureIntroductionRADARFrequenciesRADARApplicationsTypesofRADARIntroductionRADARisstandforRadioDetectionAndRangingandwasdevelopedpriortoWorldWarII.TodayRADARisextremelyimportantincivilaviation.ItisusedbyATCtomonitorandcontrolnumbersofaircraftsinairspaceaswellasbypilotforweatherwarningandnavigation.RadarFrequenciesRadaroperatesonUHFandSHF-SuperHighFrequency(1GHz-30GHz).RADARsystemsareinSHFbandsbecause:Thesefrequenciesarefreefromdisturbance.Higherfrequency,shorterwavelength,RADARmoreeffective.(shorterwavelengthsarereflectedmoreefficiently.)RADARApplicationsRADARhasawiderangeapplicationsincludingGroundRADAR:extensivelyusedbyATCtoseparateaircrafts.AirborneWeatherRADAR:usedbypilots.Itprovidepilotswithinformationregardingweatherahead.TypesofRADARGROUNDRADARA)RADARusedbyATCGroundRADARusedbyATCareusedtofixanaircraftspositionwhichallowsATCtoseparateaircraftandguidethepilot.ThreegroundRADARsystemsusedbyATCincludeEn-RouteSurveillanceRadar(RSR)TerminalApproachRadar(TAR)PrimarySurveillanceRadar(SSR)SecondarySurveillanceRadar(SSR)3.SurfaceMovementRadar(SMR)1)En-RouteSurveillanceRadar(RSR)En-RouteSurveillanceRadars(RSR)arelongrangeradarswhichthesignalgoesto300NM.Itoperateswithfrequencybetween1to2GHZ.Itusedforairwaysurveillancetoproviderangeandbearingofaircraft.**Surveillance:closeobservation,especiallyofasuspectedspyorcriminal.2)TerminalApproachRadar(TAR)TARisahighdefinitionradiodetectiondevicewhichprovidesinformationonidentification,airspeed,directionandaltitudeofaircrafttoassistairtrafficcontrollerstotrackthepositionofaircraftintheairwithinthevicinityoftheairport.Thisradargivestheairtrafficcontrollerabetterortruepictureofallaircraftflyinginhiscontrolzoneandenablehimtoeffectseparationofaircrafttoafinerdegreethanpossiblewithinformationexchangebyvoicecommunicationbetweenthepilotandthecontroller.2)TerminalApproachRadar(TAR)PSRSSRTAR

a)PrimarySurveillanceRadar(PSR)HOWPSRworksPrimarySurveillanceRadar(PSR)transmitsahighpowersignal.Whenasignalstrikesanobjectortarget,somesignalenergyisreflectedbackandisreceivedbytheradarreceiver.RADARreceiverwillplotthedirectionandthedistanceofthetarget(aircraft)fromtheradarstation.Thus,theATCcouldknowthepositionofaircraft.throughtheRADARdisplay.PrimarySurveillanceRadar(PSR)AdvantagesofPSRTheadvantagePSRisthatitoperatestotallyindependentlyofthetargetaircraft.Meansthatnoactionfromtheaircraftisrequiredforittoprovidearadarreturn.ButPSRonlyprovidedirectionanddistanceofaircraft.DisadvantagesofPSRFirst,thesignalcanbeinterruptedbybuildings,hills&mountains.Second,morepowermustberadiatedtoensurereturnsfromthetarget.Third,becauseofthesmallamountofenergyreturnedatthereceiver,reflectedsignalsmaybeeasilydisrupted.Thismaycausethedisplayedtargetto'fade‘(notclear).TAR

b)SecondarySurveillanceRadar(SSR)

HOWSSRworksSecondarySurveillanceRadar(SSR)transmitsaninterrogationsignalwhichisreceivedbythetargetaircraft.Theaircrafttranspondersendsbackacodedreplytothegroundradarequipment.Fromthecodedsignal,informationoftheaircraft’scallsign,altitude,speedanddestination.SSRrequiresanaircrafttobefittedwithtransmitter/receivercalledastransponder.HowSSRWorks?Thegroundsecondaryradartransmits1030MHzsignal.Theaircraftradarreceiveson1030MHzandtransmitsback0n1090MHz.Thetransponderreplyismorepowerfulthanthereflectedradarsignalallowingforfargreaterrange.(250nm).SSR

display

SecondaryRadarDisplayWhatappearonsecondaryradardisplay?AircraftIdentity.AltitudeSpeedDirection/DestinationExampleMH092FL280585

Meaning:FlightMalaysian092cruisingat28’000ftwithspeedof585knotsAdvantagesofSSRRequiresmuchlesstransmittingpowertoprovidecoverageupto200to250NM.Providesmoreinformation:aircraft’sidentity(itscode&callsign),indicatesaircraft’saltitude,speed&destination.Replysignalismuchstrongerasitdoesnotrelyonreturningreflectedsignals.PSRVsSSRPSRSSRTransmitsaveryhighpowerradiofrequencysignal(600kWforsubangand14kWforKLIA)ReceivedsignalisthereflectionsoftransmitsignalswhenhittingaircraftShortcoverage(60nmto80nm)Provideaircraftdirectionanddistance.Transmitlowpowerradiofrequencysignal(1kw)ReceivedsignalisasignaltransmittedfromaircrafttransponderLongcoverage(200nm)Provideaircraft’scallsign,altitude,speedanddestination.RADARservicesforMalaysia:

KualaLumpurFIRsA200NMlongrangeEn-routeSSRlocatedatBt.ChinChin,GentingHighlands,23NMeastofSubang-SultanAbdulAzizShahAirport.A60NMPSRco-mountedwitha200NMSSRlocatedtothewestofJohorBahru-SultanIsmailAirportrunway.A60NMPSRco-mountedwith200NMSSRlocatedonBt.Subang,1NMwestofSubang-SultanAbdulAzizShahAirport.RADARservicesforMalaysia:

KualaLumpurFIRs4.A60NMPrimarySurveillanceRadar(PSR)co-mountedwith200SSRlocatedatKLInternationalAirport5.A60NMPrimarySurveillanceRadar(PSR)co-mountedwith200NMSSRlocatedonHillChengkuang1.5NMNEofLangkawiInternationalAirportA60NMPSRco-mountedwitha200NMSSRlocatedtothesouthofKotaBharu-SultanIsmailPetraAirportrunway.RADARservicesforMalaysia:

KotaKinabaluFIRsA60NMPrimarySurveillanceRadar(PSR)co-mountedwith200NMSSRlocatedonBukitKepayang,1NMNEofKotaKinabaluInternationalAirport;A60NMPrimarySurveillanceRadar(PSR)co-mountedwith200NMSSRlocatedinKuchingInternationalAirport;A60NMTerminalPrimaryApproachRadarco-mountedwitha200NMSSRlocatedatMiriAirport.3)SurfaceMovementRadar(SMR)SMRinstalledatairport(attopofATCtowerbuilding)toprovideaveryaccurateradardisplayinallweathersandconditionsofvisibility.(operatewithfrequency1