Chapter 11 Marine Communication PART 1 GMDSS PART 2 VHF

Global Maritime Distress Safety System (GMDSS) GMDSS consists of several systems, some of which are new, but many of which have been in operation for many years. The system is intended to perform the following functions: alerting (including position determination of the unit in distress), search and rescue coordination, locating (homing), maritime safety information broadcasts, general communications, and bridge-to-bridge communications. Chapter 11 Marine Communication.doc

Recreational vessels do not need to comply with GMDSS radio carriage requirements, but will increasingly use the Digital Selective Calling (DSC) VHF radios. Offshore vessels may elect to equip themselves further. Vessels under 300 Gross tonnage (GT) are not subject to GMDSS requirements. In November 1998 a decade of work reached a successful conclusion when a conference held at IMO headquarters adopted amendments to the SOLAS Convention and its 1978 Protocal. The amendments were intended to introduce the GMDSS into the Convention. The date chosen for entry into force, under the SOLAS “tacit acceptance” provisions, was 1 February 1991. The new system will be phased in between 1992 and 1999. It takes into account technological advances such as satellite communications and is designed to overcome the shortcoming of the existing system, which is a combination of radiotelephone and Morse radiotelegraphy. The range of the existing system is limited to around 150 nautical miles, and reception of messages can be affected by poor propagation condition and other factors. Ships still sometimes disappear without race because a message cannot be sent in time or is not received.

The GMDSS will be a ship-to-shore, shore-to-ship and ship-to-ship system. The equipment required on board ships will depend not on their tonnage, as in the existing system, but on the sea areas in which they operate. Coastal vessels, for example, will only have to carry minimal equipment if they do not operate beyond the range of shore-based VHF radio stations. The basic concept of the system is that search and rescue authorities ashore, as well as shipping in the immediate vicinity of the ship in distress, will be rapidly alerted to a distress incident so they can assist in a co-ordinated search and rescue operation with the minimum of delay.

The system will also provide for emergency and safety communications and the dissemination of maritime safety information(MSI), including navigational and meterorological warnings. In other words, every ship will be able, irrespective of the area in which it operates, to perform those communication functions considered essential for the safety of the ship itself and of other ships operating in the same area. Although satellite will play an important part in the GMDSS, they will not completely replace existing terrestrial radio. The GMDSS combines various subsystem-which all have different limitations with respect to coverage-into one overall system, and the oceans are divided into four areas:

Area A1: Within range of VHF coast stations(20-30 miles) Area A2: Beyond area A1, but within range of MF coastal stations(about 100 miles) Area A3: Beyond the first two areas, but within coverage of geostationary maritime communication satellites(in practice this means INMARSAT). This covers the area between roughly 70degrees North and 70 degree South. Area A4: The remaining sea areas. The most important of these is the sea around the North Pole. Geostationary satellites, which are positioned above the equator, cannot reach this far.

Vocabulary protocol [5prEutEkCl] n. 议定书；调查书 headquarter [7hed5kwC:tE] n. convention [kEn5venFEn] n. 公约 tacit [5tAsit] adj. 默许的 combination [7kCmbi5neiFEn] n.联合 propagation [7prCpE5^eiFEn] n. 动植物繁殖, (声波, 电磁辐射等)传播 in vicinity of 在附近 dissemination [di7semi5neiFEn] n. 传播 meteorological [7mi:tjErE5lCdVik] adj. 气象的气象学(上)的 a meteorological observatory 气象台 the M- Office 〔英国〕气象台 a meteorological report 天气预报 a meteorological station 气象(观测)站 irrespective [7iris5pektiv] adj. 不顾的, 不考虑的, 无关的 terrestrial [ti5restriEl] adj. 陆地的, 陆生的 subsystem [5sQb7sistim] n. 分支 geostationary [7dVi(:)Eu5steiFEnEri] adj. 与地球的相对位置不变的 geostationary satellites 静止卫星

NOTES 1. GMDSS: Global Maritime Distress and Safety System 全球海上遇险与安全系统 2. EPIRB: emergency position indicating radio beacon 应急无线电示位标 3. INMARSAT: International Maritime Satellite 国际海事卫星 4. Geostationary satellites: 静止卫星 5. SART: Search and Rescue Transponder 搜救雷达应答器 6. The system will also provide for emergency and safety communications and the dissemination of maritime safety information(MSI), including navigational and meterorological warnings. 该系统也提供应急和安全通信和发布海上安全信息，包括航海警告和气象警告。

EXERCISES ______ is an area within the radiotelephone coverage of at least one VHF coast station in which continuous Digital Selective Calling is available． A．Sea Area A1 B．Sea Area A2 C．Sea Area A3 D．Sea Area A4 ______ is not required by bridge-to-bridge communications． A．VHF B．SART C．NAVTEX D．LES ______ operates at a transfer rate of up to 9600 bits per second and is telephone，telex and facsimile（fax）capable． A．INMARSAT A B．INMARSAT C C．SafetyNET D．NAVTEX

At sea，all required GMDSS equipment（other than survival craft equipment）must be proven operational by ______． A．daily testing B．either A or C C．operational use of the equipment D．testing at least every 48 hours Each satellite broadcasts ______ traffic on a designated channel． A．LES B．ESA C．NCS D．EGC 新题库海上通信答案.doc

For GMDSS，when may a compulsory vessel not be allowed to leave port ________． A．When the vessel is in an overloaded condition B．When the vessel has arranged for both duplication of equipment AND shore-based maintenance C．When the vessel has replaced a required piece of GMDSS-related equipment but its performance has not been verified or logged D．When the vessel is carrying only two licensed GMDSS Radio Operators and is capable of performing all required functions How long must the GMDSS radio log be retained on board ________． A．At least two years after the last entry B．At least one year after the last entry C．At least 90 days after the last entry D．At least 30 days after the last entry

If a GMDSS radio operator initiates a DSC distress transmission but does not insert a message，what happens ________． A．The transmission is aborted and an alarm sounds to indicate this data must be provided by the operator B．The transmission is not initiated and“ERROR”is indicated on the display readout C．The transmission will be made with“default”information provided automatically D．The receiving station will poll the DSC unit of the vessel in distress to download the necessary information Reliable delivery of messages is ensured by ______ techniques． A．forward error correction B．aftward error correction C．DGPS D．error-free and low error reception The ______ provides the link between the Space Segment and the land-based National/International fixed communications networks． A．VHF B．SART C．NAVTEX D．LES

The Consol navigation system，used in Russian and Northern European waters，can be used ______． A．For precise navigation in coastal waters B．By measuring the phase difference of the dots and dashes C．As an aid to ocean navigation D．If the vessel is fitted with a special Consol receiver The data travels from the ______ to the INMARSAT Network Coordination Station（NCS）and then down to the SES's on ships at sea． A．VHF B．SART C．NAVTEX D．LES What are the vessel equipment and personnel requirements for GMDSS ________． A．Two licensed GMDSS radio operators B．Equipment carriage requirements C．Distress alerting and response D．All of the above

What is the action that a GMDSS Radio Operator should take when a DSC distress alert is received ________． A．No action is necessary，as the DSC control unit will automatically switch to the NBDP follow-on communications frequency B．The operator should immediately set continuous watch on the radiotelephone frequency that is associated with the frequency band on which the distress alert was received C．The Operator should immediately set continuous watch on VHF channel 70 D．The Operator should immediately set continuous watch on the NBDP frequency that is associated with the frequency band on which the distress alert was received What is the most appropriate action for a GMDSS radio operator to take in a distress situation where immediate help is needed，but the vessel is not sinking nor needs to be abandoned ________． A．Switch off EPIRB and SART manually B．Transmit distress call by MF/HF，VHF or INMARSAT C．Notify the RCC（Rescue Coordination Center）through VHF FM on channel 13 D．Transmit distress call by activating the radiotelegraph automatic alarm signal

What publications should a GMDSS Operator consult regarding the proper set-up and operation of vessel equipment ________． A．ITU Publications B．The manufacturers instruction manuals C．Part 90 of the FCC Rules and Regulations D．Code of Federal Regulations，Title 47，Part 80，Subpart W When the GMDSS Radio Operator on watch hears“SECURITE”spoken three times he can expect to receive a message concerning ______． A．The safety of navigation or important meteorological warnings B．The safety of a vessel or a person is in jeopardy C．A vessel in need of immediate assistance D．A coast station traffic list Where should the GMDSS radio log be kept on board ship ________． A．In the Captain's office B．In the sea cabin C．At the GMDSS operating position D．Anywhere on board the vessel

Which action should be taken on receipt of a GMDSS distress alert ________． A．Read the display screen and/or printout B．Silence the alarm C．Listen for any follow up voice/telex transmission on the appropriate frequency D．All of the above Which categories of NAVTEX messages may not be selectively rejected through receiver programming ________． A．Navigational warnings B．Weather warnings C．SAR and distress alert information

Which device provides the main means in the GMDSS for locating ships in distress or their survival craft ________． A．Radio direction finder B．Satellite EPIRBs C．MF/HF DSC D．VHF homing device Which frequencies and modes are allocated for distress alerting in GMDSS ________． A．406 MHz via EPIRB B．1626.5-1645.5 via INMARSAT C．Channel 70 DSC plus six（6）MF/HF DSC frequencies D．All of the above Which maintenance functions can a GMDSS Radio Operator perform ________． A．The Operator can make fine internal adjustments to the transmitter as long as the output power does not change by more than one percent B．The Operator is responsible for ensuring that INMARSAT antennas are free of built-up soot and clear of obstacles C．All levels of maintenance must be performed by a licensed GMDSS Radio Maintainer D．The Operator may install an EPROM in order to ensure that the equipment continues to operate within legal constraints

Which message categories cannot be disabled by the GMDSS radio operator ________． A．Navigational Warnings B．Meteorological Warnings C．Search and Rescue Information D．All of the above Which statement concerning GMDSS Radio Operator requirements is FALSE ________． A．Each compulsory vessel must carry at least two licensed GMDSS Radio Operators at all times while at sea B．Each compulsory vessel must carry at least two licensed Radio Operators at all times while at sea and may elect to carry a GMDSS Radio Maintainer as well C．Communications involving safety of life at sea do not have to be logged as long as the compulsory vessel was not involved in such communications D．While at sea，adjustments to，and the maintaining of，GMDSS equipment may be performed by the GMDSS Radio operator as long as the work is supervised by an onboard licensed GMDSS Radio Maintainer

Which statement concerning reserve sources of energy for GMDSS is FALSE ________． A．While the ship is at sea，there must be available at all times a supply of electrical energy sufficient to operate the radio installations and to charge any batteries used as part of a reserve source of energy B．Both the VHF and MF/HF installations must be simultaneously supplied C．A means of ensuring a continuous supply of electrical power must be provided to all GMDSS equipment that could be affected by an interruption in power D．If a UPS or equivalent is used to supply power to the ship's GPS receiver or other source of positional information，a means must be provided to ensure the continuous supply of the information in the event of a failure to the ship's main or emergency source of power Which statement concerning satellite EPIRBs is TRUE ________． A．Once activated，these EPIRBs continuously send up a signal for use in identifying the vessel and for determining the position of the beacon B．The coded signal identifies the nature of the distress situation C．The coded signal only identifies the vessel's name and port of registry D．If the GMDSS Radio Operator does not program the EPIRB，it will transmit default information such as the follow-on communications frequency and mode Which statement is generally correct regarding the maintenance requirements for ships under GMDSS ________． A．Redundancy of functions of certain equipment will partially meet this requirement B．On-board maintenance provided by a person holding a GMDSS maintainer's license will partially meet the requirements C．Shoreside maintenance and scheduled tests and inspections will partially meet this requirement D．All of the above

Which statement is TRUE ________． A．GMDSS radio logs are required to contain entries pertaining to all incidents connected to radio communication service which appear to be of importance to the safety of life at sea B．All distress communications must be entered in the GMDSS radio log． C．Both of the above D．None of the above A．Key letters or abbreviations may not be used in GMDSS radio logbooks under any circumstance B．Urgent communications do not need to be entered in the GMDSS radio log You are signing on a deck officer，who will be designated as one of the GMDSS operators，before sailing foreign．Which statement is TRUE ________． A．He/she must have an STCW certificate endorsed as“Valid for Service on Vessels Operating in the GMDSS System” B．He/she must present either an FCC-issued license or a Coast Guard-issued license C．You must consult the“List of Qualifications”on the reverse of his/her FCC-issued license D．His/her Merchant Mariners Document must have an added endorsement as “Radio Electronics Officer” 新题库海上通信答案.doc

Thank You!