G证英语阅读.docx
《G证英语阅读.docx》由会员分享,可在线阅读,更多相关《G证英语阅读.docx(27页珍藏版)》请在冰豆网上搜索。
G证英语阅读
GMDSS英语阅读练习题
(一)DigitalSelectiveCallingSystem
Introduction
DigitalSelectiveCalling(DSC)isanintegralpartoftheGMDSSandisusedfortransmittingdistressalertsfromshipsandfortransmittingtheassociatedacknowledgementsfromcoaststations.TheDSCsystemisverycomprehensiveandcatersforthesettingupofalltypesofcallsusinginternationallyagreedcodes.Itisalsousedbyshipsandcoaststationsforrelayingdistressalertsandforotherurgencyandsafetycalls.DSCencoders/decoders,insomecircumstances,canbeinterfacedwithexistingequipment.AdedicatedDSCwatchreceiverisrequiredtokeepcontinuouswatchonthedistressfrequency,thiscanbeasimplesinglechannelreceiver.
BasicDescriptionofDSC
DSCisbasicallyacallingsystem.Eachcallconsistsofa‘packet’ofdigitisedinformationofoneoffourpriorities:
Distress,Urgency,SafetyorRoutine.Messagescanberoutedto“AllStations”,toanindividualstationortoagroupofstations,usingtheirMaritimeMobileSelective-callidentitycode(MMSI).Distressmessagesareautomaticallybroadcastto“AllStations”.
InadditiontotheMMSIofsourceanddestinationstations,informationcanbeconveyedintheDSCmessage.Forexample,toaidtheRescueServices,theDSCDistressalertmessageisconfiguredtocontainthefollowing:
Ship’sidentity(theninedigitMMSI);
Time;
Natureofdistress(intheformofastandardcode);
Ship’sposition.
Wherefitted,ship’sofficersshouldensuretheyarefullyconversantwiththeprocedureforenteringthenecessaryinformationintotheDSCequipment.Atsea,unlessprovidedautomaticallyfromanavigationsystem,ship’spositionshouldbeupdatedatleastonceduringeachwatchperiod.
Question:
1、EachDSC”PACKET”havepriority(priorities)
A、1B、2C、3D、4
2、Whichofthefollowingstaementisnottrue&nbds?
A、DSCmessagehasaMMSIofsourcestation
B、DSCmessagehasaMMSIofsourcestation
C、DSCmessagehasanameofsourcestation
D、ADSCmessagealsohasotherinformationforsendinground.
3、Whichofthefollowingstatementistrue?
A.Noteveryshipisrequiredtokeepcontinuouswatchonthedistressfrequency.
B.Ashipcankeepawatchonthedistressfrequencyatthetimeitthinksconvenient.
C.AnexclusiveDSCwatchreceiverisrequiredtokeepcontinuouswatchonthedistressfrequencies.
D.Asimplesinglechannelreceiverisnotsuitableforkeepingcontinuouswatchonthedistressfrequency.
4、atsea,ifdscequipmentcannotgetshiispositionmessagefromanavigationsystemautomatically,thenthepositionmessageshouldberenewed
A、atleastevery4hours
B、atleastevery8hours
C、atleastevery12hours
D、atleastevery24hours
5、accordingtothemessage,distressmessagecanbereceivedby()
A、ALLSTATION
B、COASTSATION
C、SHIPSTATION
D、GROUPOFSPECIFIEDSTATION
(二)
NAVTEXsystem
TheNAVTEXreceiverisaNarrowBandDirectPrinting(NBDP)deviceoperatingonthefrequency518Khz,(someequipmentcanalsooperateon490Khzand4209.5Khz),andisavitalpartoftheGlobalMaritimeDistressandSafetySystem(GMDSS).
ItisautomaticallyreceivesMaritimeSafetyInformationsuchasRadioNavigationalWarnings,Storm/GaleWarnings,MeteorologicalForecasts,PiracyWarnings,DistressAlertetc.
Theinformationreceivedisprintedonthereceiver’sownpaperrecorderroll.Eachmessagebeginswithstartsofmessagefunction(ZCZC)followedbyaspacethenfourBcharacters.TheFirst,(B1),identifiesthestationbeingreceived,thesecond,(B2),identifiesthesubjecti.e.NavigationalWarning,MetForecastetc,andthethirdandfourth,(B3+B4),formtheconsecutivenumberofthemessagefromthatstation.Thisfollowedbythetextofthemessageandendswithanendofmessagefunction(NNNN).
TheNAVTEXsystembroadcastsCOASTALWARNINGwhichcovertheareafromthefairwaybuoyoutto250nauticalmilesfromthetransmitter,thetransmissionfromsometransmitterscanbereceivedoutto400nauticalmilesandevenfurtherinunusualpropagationconditions.
Question:
1.WhichfrequencyistheNAVTEXreceiverusuallyoperatingon?
A.490KhzB.4209.5KhzC.518KhzD.2182Khz.
2.Eachmessagebeginswithstartsofmessagefunction()?
A.NNNNB.KKKKC.ZCZCD.NCNC
3、WhichofthefollowingisnoTRUE?
A、Eachmessagebeginwithstartsofmessagefunction(ZCZC)
B、Eachmessageendswithanendofmessagefunction(nnnn)
C、THENAVTEXsystemcancoverthe250milesfromthetransmitter
D、THENAVTEXsystemcannotcover400milesfromthetransmitter
(三)
TerrestrialCommunications
Long-RangeService
UseofHFprovidesalong-rangserviceinboththeship-to-shoreandshore-to-shipdirections.IncasecoveredbyINMARSATitcanbeusedasanalternativetosatellitecommunicationsandoutsidetheseareasitprovidestheonlylong-rangcommunicationcapability.Frequencieshavebeendesignatedinthe4,6,8,12and16MHzbandsforthisservice.
Digitalselectivecalling(DSC)formsthebasisofdistressalertingandsafetycommunications.DistressandsafetycommunicationsfollowingaDSCcallcanbeperformedbyradiotelephoneorNBDP.
Medium-RangeService
Amedium-rangeserviceisprovidedonfrequenciesinthe2MHzband.Intheshiptoshore,shiptoshipandshoretoshipdirections2187.5kHzwillbeusedfordistressalertsansafetycallsusingDSC,and2182kHzwillbeusedfordistressandsafetytrafficbyradiotelephone,includingSARco-ordinatindandon-scenecommunications.2174.5kHzwillbeusedforradiotelex(NBDP)distressandsafetytraffic.
Question:
1.Whichfrequencywillbeusedfordistressandsafetytrafficbyradiotelephone?
A.2187.5kHzB.2182kHzC.2174.5kHzD.2152kHz
2、TheHFcanprovidetheservicewhichis
A、notcoveredbyINMARSAT
B、onlyshort-rangeservice
C、onlyMedium-RangeService
D、coveredbyINMARSAT
3、Whichofthefollowingistrue?
A、Digitalselectivecalling(DSC)followsatelephonecall
B、DistressandsafetycommunicationsbyradiotelephoneorNBDPfollowsaDSCdistresscall
C、Digitalselectivecalling(DSC)followsNBDPtraffic
D、Radiotelephonealertformsthebasisofdistressalertingandsafetycommunication
(四)
Digitalselectivecalling(DSC)onVHF,MFandHF
TheIMOalsointroduceddigitalselectivecalling(DSC)onVHF,MFandHFmaritimeradiosaspartoftheGMDSSsystem.DSCisprimarilyintendedtoinitiateship/ship,ship/shore,andshore/shipradiotelephoneandMF/HFradiotelexcalls.DSCcallscanalsobemadetoindividualshipsorgroupsofships.DSCdistressalerts,whichconsistofapreformatteddistressmessage,areusedinitiateemergencycommunicationswithshipsandrescuecoordinationcenters.Whenfullyimplemented,DSCwilleliminatetheneedforpersonsonaship’sbridgeoronshoretocontinuouslyguardradioreceiversonvoiceradiochannels,includingVHFchannel16(156.8MHz)and2182kHznowusedfordistress,safetyandcalling.AlisteningwatchaboardGMDSS-equippedshipson2182kHzendedon1February1999,andonVHFchannel16isscheduledtoendon1February2005.
WeurgethattheDSC-equippedVHFandMF/HFradiosbeexternallyconnectedtoasatellitenavigationreceiver.Thatconnectionwillensureaccuratelocationinformationissenttoarescuecoordinationcenterifadistressalertisevertransmitted.FCCregulationsactuallyrequirethatship’spositionbemanuallyenteredintotheradioeveryfourhoursonshipsrequiredtocarryGMDSSequipment,whilethatshipisunderway(47CFR80.1073).
OnceSOLASshipsareallowedtodisbandwatch-keepingonVHFandMFradiotelephonechannels,othershipsaregoingtoneedDSC-equippedradiostocontacttheseships,particularlyinapassingsituation,especiallywhenoutsideU.S.waters.WebelieveVHF,MFandHFradiotelephoneequipmentcarriedonshipsshouldincludeaDSCcapabilityasamatterofsafety.Toachievethis,theFCCrequiresthatallnewVHFandMF/HFmaritimeradiotelephonestypeacceptedafterJune1999tohaveatleastabasicDSCcapability.
VHFdigitalselectivecallingalsohasothercapabilitiesbeyondthoserequiredfortheGMDSS.TheCoastGuardusesthissystemtotrackvesselsinPrinceWilliamSound,Alaska,VesselTrafficService.IMOandtheUSCGalsoplantorequireshipscarryaUniversalAutomaticIdentificationSystem,whichwillbeDSC-compatible.CountrieshavingaGMDSSA1AreawillbeabletoidentifyandtrackAIS(自动识别系统)-equippedvesselsinitswaterswithoutanyadditionalradioequipment.
Question:
1、Accordingtothismessage,thewatch-keepingofVHFCH16willbeended_______.
A.on1February1999.B.on1February2005.C.on1February2000.D.on1February2010.
2、Thewriterintendsthatthevhf/mf/hfradioequipment
A、shouldhaveitsownsatellitenavigator
B、havenothingtodowiththesatellingnavigationsystem
C、shouldbeconnectedtoastatellitenavigator
D、shouldchangetheshipispositionmanuallyeveryhours
3、Whichstatementisnotcorrect?
A、DSCcaninitiateradio-telephoneandradiotelexcallsonVHF/HF/MFbands.
B、DSCcaninitiateradio-telephonecallsonVHF/HF/MFbands.
C、DSCcaninitiaterdiotelexcallsonHF/MFbands
D、DSCcaninitiateVHF/HF/MFradio-telephoneandHF/MFrdiotelexcalls
4、TheAISequipmentwillbeusedto
A、identifityandtrackvesselsinA1area
B、identifityandtrackvesselsinA2area
C、identifityandtrackvesselsinA3area
D、identifityandtrackvesselsinA4area
5、Themeaningofword“rdios”inthepassageis
A、radioequipments
B、radiowaves
C、radioprograms
D、nomeaning
(五)ThreetypesshipearthstationterminalsofInmarsat
SatellitesystemsoperatedbytheInternationalMobileSatelliteOrganization(Inmarsat),arealsoimportantelementsoftheGMDSS.ThreetypesofInmarsatshipeart