G证英语阅读.docx

1、G证英语阅读 GMDSS英语阅读练习题（一） Digital Selective Calling SystemIntroductionDigital Selective Calling (DSC) is an integral part of the GMDSS and is used for transmitting distress alerts from ships and for transmitting the associated acknowledgements from coast stations. The DSC system is very comprehensive a

2、nd caters for the setting up of all types of calls using internationally agreed codes. It is also used by ships and coast stations for relaying distress alerts and for other urgency and safety calls. DSC encoders/decoders, in some circumstances, can be interfaced with existing equipment. A dedicated

3、 DSC watch receiver is required to keep continuous watch on the distress frequency, this can be a simple single channel receiver.Basic Description of DSCDSC is basically a calling system. Each call consists of a packet of digitised information of one of four priorities: Distress, Urgency, Safety or

4、Routine. Messages can be routed to “All Stations”, to an individual station or to a group of stations, using their Maritime Mobile Selective-call identity code (MMSI). Distress messages are automatically broadcast to “ All Stations”.In addition to the MMSI of source and destination stations, informa

5、tion can be conveyed in the DSC message. For example, to aid the Rescue Services, the DSC Distress alert message is configured to contain the following:Ships identity ( the nine digit MMSI);Time;Nature of distress ( in the form of a standard code);Ships position.Where fitted, ships officers should e

6、nsure they are fully conversant with the procedure for entering the necessary information into the DSC equipment. At sea, unless provided automatically from a navigation system, ships position should be updated at least once during each watch period.Question: 1、Each DSC”PACKET”have priority(prioriti

7、es)A、1 B、2 C、3 D、42、Which of the following staement is not true &nbds?A、DSC message has a MMSI of source stationB、DSC message has a MMSI of source stationC、DSC message has a name of source stationD、A DSC message also has other information for sending round.3、Which of the following statement is true?

8、A. Not every ship is required to keep continuous watch on the distress frequency.B. A ship can keep a watch on the distress frequency at the time it thinks convenient.C. An exclusive DSC watch receiver is required to keep continuous watch on the distress frequencies.D.A simple single channel receive

9、r is not suitable for keeping continuous watch on the distress frequency.4、at sea ,if dsc equipment can not get shi is position message from a navigation system automatically,then the position message should be renewedA、at least every 4 hoursB、at least every 8 hoursC、at least every 12 hoursD、at leas

10、t every 24 hours5、according to the message ,distress message can be received by( )A 、ALL STATIONB、COAST SATION C、SHIP STATIOND、GROUP OF SPECIFIED STATION(二)NAVTEX systemThe NAVTEX receiver is a Narrow Band Direct Printing (NBDP) device operating on the frequency 518Khz, (some equipment can also oper

11、ate on 490Khz and 4209.5Khz), and is a vital part of the Global Maritime Distress and Safety System (GMDSS).It is automatically receives Maritime Safety Information such as Radio Navigational Warnings, Storm/Gale Warnings, Meteorological Forecasts, Piracy Warnings, Distress Alert etc.The information

12、 received is printed on the receivers own paper recorder roll. Each message begins with starts of message function (ZCZC) followed by a space then four B characters. The First, (B1), identifies the station being received, the second, (B2), identifies the subject i.e. Navigational Warning, Met Foreca

13、st etc, and the third and fourth, (B3+B4), form the consecutive number of the message from that station. This followed by the text of the message and ends with an end of message function (NNNN).The NAVTEX system broadcasts COASTAL WARNING which cover the area from the fairway buoy out to 250 nautica

14、l miles from the transmitter, the transmission from some transmitters can be received out to 400 nautical miles and even further in unusual propagation conditions.Question: 1. Which frequency is the NAVTEX receiver usually operating on?A. 490Khz B. 4209.5Khz C. 518Khz D. 2182 Khz. 2. Each message be

15、gins with starts of message function ( )?A. NNNN B. KKKK C. ZCZC D. NCNC3、Which of the following is no TRUE?A、Each message begin with starts of message function(ZCZC)B、Each message ends with an end of message function(nnnn)C、THE NAVTEX system can cover the 250miles from the transmitterD、THE NAVTEX s

16、ystem can not cover 400 miles from the transmitter(三)Terrestrial CommunicationsLong-Range ServiceUse of HF provides a long-rang service in both the ship-to-shore and shore-to-ship directions. In case covered by INMARSAT it can be used as an alternative to satellite communications and outside these a

17、reas it provides the only long-rang communication capability. Frequencies have been designated in the 4,6,8,12 and 16 MHz bands for this service.Digital selective calling (DSC) forms the basis of distress alerting and safety communications. Distress and safety communications following a DSC call can

18、 be performed by radiotelephone or NBDP.Medium-Range ServiceA medium-range service is provided on frequencies in the 2 MHz band. In the ship to shore, ship to ship and shore to ship directions 2187.5kHz will be used for distress alerts an safety calls using DSC, and 2182kHz will be used for distress

19、 and safety traffic by radiotelephone, including SAR co-ordinatind and on-scene communications. 2174.5kHz will be used for radiotelex (NBDP) distress and safety traffic.Question: 1. Which frequency will be used for distress and safety traffic by radiotelephone? A. 2187.5 kHz B. 2182 kHz C. 2174.5kHz

20、 D. 2152kHz2、The HF can provide the service which is A、not covered by INMARSATB、only short-range serviceC、only Medium-Range ServiceD、covered by INMARSAT3、Which of the following is true ?A、Digital selective calling(DSC) follows a telephone callB、Distress and safety communications by radiotelephone or

21、 NBDP follows a DSC distress callC、Digital selective calling(DSC) follows NBDP trafficD、Radio telephone alert forms the basis of distress alerting and safety communication(四)Digital selective calling (DSC) on VHF, MF and HFThe IMO also introduced digital selective calling (DSC) on VHF, MF and HF mar

22、itime radios as part of the GMDSS system. DSC is primarily intended to initiate ship/ship, ship/shore, and shore/ship radiotelephone and MF/HF radiotelex calls. DSC calls can also be made to individual ships or groups of ships. DSC distress alerts, which consist of a preformatted distress message, a

23、re used initiate emergency communications with ships and rescue coordination centers. When fully implemented, DSC will eliminate the need for persons on a ships bridge or on shore to continuously guard radio receivers on voice radio channels, including VHF channel 16 (156.8 MHz) and 2182 kHz now use

24、d for distress, safety and calling. A listening watch aboard GMDSS-equipped ships on 2182 kHz ended on 1 February 1999, and on VHF channel 16 is scheduled to end on 1 February 2005. We urge that the DSC-equipped VHF and MF/HF radios be externally connected to a satellite navigation receiver. That co

25、nnection will ensure accurate location information is sent to a rescue coordination center if a distress alert is ever transmitted. FCC regulations actually require that ships position be manually entered into the radio every four hours on ships required to carry GMDSS equipment, while that ship is

26、underway (47 CFR 80.1073). Once SOLAS ships are allowed to disband watch-keeping on VHF and MF radiotelephone channels, other ships are going to need DSC-equipped radios to contact these ships, particularly in a passing situation, especially when outside U.S. waters. We believe VHF, MF and HF radiot

27、elephone equipment carried on ships should include a DSC capability as a matter of safety. To achieve this, the FCC requires that all new VHF and MF/HF maritime radiotelephones type accepted after June 1999 to have at least a basic DSC capability. VHF digital selective calling also has other capabil

28、ities beyond those required for the GMDSS. The Coast Guard uses this system to track vessels in Prince William Sound, Alaska, Vessel Traffic Service. IMO and the USCG also plan to require ships carry a Universal Automatic Identification System, which will be DSC-compatible. Countries having a GMDSS

29、A1 Area will be able to identify and track AIS(自动识别系统)-equipped vessels in its waters without any additional radio equipment.Question: 1、According to this message, the watch-keeping of VHF CH16 will be ended _.A. on 1 February 1999. B. on 1 February 2005. C. on 1 February 2000. D. on 1 February 2010

30、.2、The writer intends that the vhf/mf/hf radio equipment A、should have its own satellite navigator B、have nothing to do with the satelling navigation systemC、should be connected to a statellite navigatorD、should change the ship is position manually every hours 3、Which statement is not correct?A、DSC

31、can initiate radio-telephone and radiotelex calls on VHF/HF/MF bands.B、DSC can initiate radio-telephone calls on VHF/HF/MF bands.C、DSC can initiate rdiotelex calls on HF/MF bandsD、DSC can initiate VHF/HF/MF radio-telephone and HF/MF rdiotelex calls4、The AIS equipment will be used to A、identifity and

32、 track vessels in A1areaB、identifity and track vessels in A2areaC、identifity and track vessels in A3areaD、identifity and track vessels in A4area5、The meaning of word “rdios” in the passage is A、radio equipmentsB、radio wavesC、radio programsD、no meaning(五) Three types ship earth station terminals of Inmarsat Satellite systems operated by the International Mobile Satellite Organization (Inmarsat), are also important elements of the GMDSS. Three types of Inmarsat ship eart