海上无线电通信业务简答题
无线通信问答题
问答题1.简述无线电通信按所用波段可分为哪几类?答:无线电通信按所用波段可分为长波通信、中波通信、短波通信、超短波通信和微波通信等。
2.简述无线长波通信的应用领域。
答:长波通信多用于海上通信、水下通信、地下通信和导航等;由于传播稳定,受太阳耀斑或核爆炸引起的电离层骚扰的影响小,也可用作防电离层骚扰的备用通信手段。
六、论述题1.阐述无线通信的基本原理。
答:由电荷产生电场,电流产生磁场,电荷和电流交替消长的振动可在其周围空间产生互相垂直的电场与磁场、并以光速向四周辐射的电磁波。
电磁波以直线形式在均匀介质中传播,遇到不同介质或障碍物时,会产生反射、吸收、折射、绕射或极化偏转等现象。
为把信息通过无线电波送往远方,必须以电波作为载体,即用变更电波的幅度、频率或相位使信息附加到载频上去,分别称为调幅、调频或调相,统称调制。
经过调制的电波可在传输媒质中传输到达接收地点,然后再将所需信息提取出来还原,称为解调(反调制)。
以上介绍的就是无线通信的基本原理。
2.用信道的相干时间(td)或多普勒频移(fd)来描述发送电波信号时信道时变的快慢衰落。
答:当发送信号的码元时间Ts与多普勒频移fd的乘积远小于1时,即fdTs<<1,此时在每个码元时间内,信号的时变因素可以忽略,称此时发送信号经历慢衰落;当发送信号的码元时间Ts与多普勒频移fd的乘积与1可比时,此时每个码元时间内,信号的时变因素不可以忽略,发送信号经历快衰落。
1.简述无线通信信道的基本特征。
答:无线通信信道的基本特征主要表现在三个方面:一是带宽有限,它取决于可使用的频率资源和信道的传播特性;二是干扰和噪声影响大,这主要是无线通信工作的电磁环境所决定的;三是在移动通信中存在多径衰落,在移动环境下,接收信号起伏变化。
2.简述无线分集技术的含义。
答:分集有两重含义:一是分散传输,使接收端能获得多个统计独立的、携带同一信息的衰落信号;二是集中处理,即接收机把收到的多个统计独立的衰落信号进行合并,以降低衰落的影响。
GMDSS设备课后问答题 整理版
本提纲为航海1417 白兴超整理,仅供航海1417-141C班适用。
以下所有简答题就是老师划得重要简答题以及个人认为重要得题目。
仅供参考复习,如有异议,请指出,谢谢第1章1、原海上通信系统与GMDSS相比存在哪些局限性?1)可靠通信距离近2)需要经过专门训练得报务员才能适任海上遇险报警与通信3)报警设备得自动化与可靠性能差,受人为因素影响大4)远距离报警手段单一,全球覆盖能力差5)对遇险船舶得搜救缺乏有效得国际协调与合作6)常规通信手段落后,通信自动化程度低2、简述GMDSS得基本含义。
GMDSS就是从何时开始全面实施得?GMDSS全称为global maritime distress and safety system,就就是全球海上遇险与安全系统得缩写。
该系统主要由卫星通信系统—INMARSAT (海事卫星通信系统) 与COS-PAS/SARSAT(极轨道卫星搜救系统)、地面无线电通信系统(即海岸电台)以及海上安全信息播发系统三大部分构成。
1999年2月1日。
3、GMDSS主要有哪些功能?(1)遇险报警,三个方向;(2)搜救协调通信;(3)救助现场通信;(4)救助现场寻位;(5)海上安全信息(MSI)得播发与接收;(6)快捷高效得常规通信;(7)驾驶台对驾驶台通信;4、GMDSS现场寻位功能就是怎样实现得?(1)Radar-SART:通过遇险目标携带得搜救雷达应答器SART与救助船或飞机上得X波段雷达所构成得寻位系统实现。
当遇险目标携带得Radar-SART被救助船或飞机上得X波段雷达信号触发时,救助船或飞机上得雷达屏幕就会显示出遇险目标得相对位置,从而迅速发现遇险目标,达到及时救助得目得。
(2)AIS-SART:当船舶遇险时,开启AIS-SART,会在AIS得专用信道上自动发射遇险报警信息,主要包括遇险船得位置与识别码等信息,周围船舶收到该特殊信息后,可以很快确定遇险船舶得位置,从而便于救援人员对遇险目标进行迅速准确得定位,并实现及时救助。
GMDSS业务简答题
1.《无线电信号书》各卷内容、查阅及修改。
<<无线电信号书>>全书共分六卷,其中第一卷和第三卷各分两册,第六卷分七册。
第一卷主要内容:各国海岸电台开放的公众通信业务、医疗指导、检疫报告、防污染、INMARSAT业务、防武装、防海盗、防走私、国际无线电规则。
第一册主要范围欧、非、亚,第二册主要范围美、大洋、远东。
第二卷主要内容:无线电助航仪器、无线电报时信号、电子定位系统及相关图表。
第三卷主要内容:介绍无线电气象业务、航行警告和MSI播发情况(包括NAVTEX和NAVAREA )。
第一册主要范围欧、非、亚,第二册主要范围美、大洋、远东。
第四卷主要内容:气象观测台(WMO世界气象组织)。
第五卷主要内容:GMDSS系统的介绍(包括有关SOLAS公约规则、DSC业务、SART业务、MSI业务、INMARSAT和COSPAS-SARSAT系统)、遇险搜救程序及相关的图表等。
(6)第六卷主要内容:港口操作业务、VTS系统和业务信息、船舶报告系统、船舶引行业务。
3.试述VHF CH6/CH13/CH16/CH70的功能和使用。
①CH16 156.8MHz。
国际遇险与安全频率,遇险紧急安全通信,人工呼叫航行信息。
CH75,76为保护频道。
②CH6 主要用于遇险现场搜救协调的船与飞机之间的通信。
国内航行的船舶应保持值守,船舶间导航避让。
船与船,船岸间呼叫常在CH16频道上进行。
岸船:工作频率或双方指定的双工频率。
③CH13 为航行安全通信频道,主要用于船舶间的航行安全通信,因此国际航行的船舶在该通道上值守。
④CH70(156.525MHz)VHF DSC遇险与安全频率。
航行船舶必须在该频率保持值守。
4.INMARSAT-B系统开放的主要业务:遇险通信业务、电话/电传通信业务、传真通信业务、数据通信业务、其他特别业务如:慢扫描电视呼叫业务。
4.INMARSAT-C系统开放的主要业务:A.存储转发业务:电传业务、传真业务、电子邮件业务、船至船通信业务。
海上无线电通信业务选择题
1.____是船舶电台的呼号A. 9VGB. BAAD1C. XSF26D. BOAD2.电台工作日志,国内各类来往电报保管期为____A. 半年/一年B. 一年/二年C. 一年/半年D. 二年/一年3.气象报告和航行警告的保管期为____A. 半年B. 三个月C. 一年D. 二年4.GMDSS船舶无线电人员需每天至少提供____无线电时间信号以修正船舶天文钟A. 一次B. 二次C. 三次D. 四次5.现场通信使用无线电话频率应选择____A. 156.8MHzB. 2182KHzC. 2174.5KHzD. A和B6.DSC遇险呼叫中, 如通信方式使用无线电话,应选择____A. 2187.5/2177.0KHZB. 2187.5/2182.0KHZC. 2187.5/4177.5KHZD. 2187.5/2174.5KHZ7.____不是DSC遇险呼叫频率和无线电话遇险通信频率A. 6312.0/6215.0B. 2187.5/2182.0C. 8414.5/8376.5D. 12577/12290.08.船舶在A2海区遇险使用DSC报警,频率应为____A. 2182KHzB. 2174.5KHzC. 2191KHzD. 2187.5KHz9.当航空器参与协调救助作业时可使用的频率____A. 3023KHzB. 5680KHzC. 156.8MHzD. A、B、C均是10.使用无线电传进行现场通信频率应是____A. 2174.5KHzB. 2182.0KHzC. 2187.5KHzD. CH16频道11.____是用于海岸电台以FEC方式发送MSI的频率A. 8291KHzB. 8376.5KHzC. 8415KHzD. 8416.5KHz12.使用中频进行国际DSC常规呼叫时应选择____频率A. 458.5/455.5KHZB. 2187.5/2187.5KHZC. 4208.0/4219.5KHZD. 6312.5/6331.0KHZ13.____不是DSC遇险呼叫频率A. 2187.5KHzB. 2182.0KHzC. 8414.5KHzD. 4207.5KHz14.救生艇手提式VHF双向无线电话,必须具备____频道A. CH6B. CH16C. CH70D. CH1315..国际上规定VHF 6频道用于____A. 无线电遇险和安全通信B. 船舶雾航避让,防台联系C. 船-船有关航行安全的通信D. 船舶与航空器之间进行协调搜救行动通信16.在GMDSS中,要求VHF无线电话设备应能在____频道上发送和接收DSC信息A. 6B. 13C. 16D. 7017..救生艇手提式双向无线电话工作频道要求____A. VHFCH16和至少另外一个频道B. VHFCH16和至少另外二个频道C. VHFCH16和至少另外一个单工频道D. VHF任意二个频道18.船岸台进行ARQ通信时,工作频率应选用____A. 非成对频率B. 指定的成对频率C. 自定任选频率D. A. B. C均是19.在GMDSS中,使用NBDP设备进行遇险通信的频率应是____A. 收、发频率相同B. 收、发频率不同C. 发射频率高于接收频率D. 接收频率高于发射频率20.在NBDP遇险通信中,对干扰电台强制静默使用信号_____A. SILENCE MAYDAYB. SEELONCE MAYDAYC. SEELONC EFINID. SILENCE FEENEE21.无线电话遇险通信中,遇险通信结束恢复正常工作使用信号_____A. SILENCE FINIB. SEELONCE FEENEEC. SEELONCE FINID. SILENCE FEENEE22.无线电传遇险通信中,恢复正常工作使用信号_____A. QUMB. SEELONCE FEENEEC. SEELONCE MAYDAYD. SILENCE FINI23._____是海岸电台的呼号A. 9VG98B. XSFC. XSG26D. A、B、C都是24.组成海岸电台呼叫识别的结构为____A. 0MIDX5X6X7X8X9B. 00MIDX6X7X8X9C. 000MIDX7X8X9D. MIDX4X5X6X7X8X925.水上移动业务识别为041234500是船舶电台标识的____A. 区域型式B. 国内型式C. 全球型式D. 成组呼叫识别26.水上识别数字(MID)的首位数是6代表的区域是____A. 非洲B. 南美洲C. 欧洲D. 大洋洲27.____是我国船舶电台的MMSIA. 047735000B. 004122100C. 412123000D. 21944257328.MMSI标识由____数字组成A. 三位B. 五位C. 七位D. 九位29.水上移动业务标识(MMSI)为412345670是船舶电台的____A. 国内型式B. 区域型式C. 全球型式D. 群呼型式30.海上移动业务识别中,中国的海上识别码(MID)为____A. 085B. 086C. 581D. 41231.____是INMARSAT-B站海上移动业务识别码(IMN)A. 341234610B. 441234650C. 1570174D. 41254181032.海事卫星水上移动业务识别码结构为TX1X2…Xk,其中T是用于区分海事卫星不同的系统,当T为0时表示为____A.A标准移动业务B. A标准群呼C. B标准移动业务D. A标准特别业务33.____应是C船站的IMNA. 1570152B. 441210810C. 004212100D. 41212300034.在我国的陆上用户电传应答码中,我国的国家标识用____表示A. CHINAB. CHNC. CND. CY35.无线电话遇险信号由____组成A. PANPANB. SOSC. MAYDAYD. SECURITE36.无线电传的紧急信号是____A. PANPANB. PANPAN三次C. XXXD. XXX三次37.在GMDSS中,无线电话的安全信号是由____组成的A. SECURITEB. PANPANC. MAYDAYD. XXX38.船舶在HF/DSC上收到DSC遇险报警,____后仍无海岸电台发射收妥承认,则该船台应进行遇险报警转播。
GMDSS通信英语上海500题带翻译
英语阅读500题(单项选择题)1.IMO has decided决定that all ships over 300TGt must be fitted with a NA VTEX receiver______ .IMO在什么时候决定300总吨以上必须配备NA VTEX接收机。
A. by 01 Feb 1992B. by 01 Aug 1993C. between 01 Feb 1992 and 01 Feb 1999D. before 01 Feb 19922.GMDSS is to provide ______ with reliable可靠的communication .GMDSS提供给--所有客船和300总吨及以上货船在海上航行--的可靠通信。
A. all large passenger vesselsB. freighters of more than 300gt in coastal watersC. all passenger ships and cargo ships engaged in international-voyagesD. all passenger ships and cargo ships of 300gt upwards in open sea3.The complying遵从vessels can transmit ship-to-shore distress alerts by at least ______ .这个遵守船舶(公约船)能发送船到岸遇险报警至少通过--两套分开和独立设备方法,使用不同的无线电通信业务。
A. One means, whether satellite or terrestrial techniquesB. Two means,途径whether无论satellite or terrestrial techniquesC. Two separate and independent独立的means, each using different radio communication servicesD. Two means, such as MF DSC and HF DSC4.The quality of the message can be affected 受到影响by ___ .信息的质量会受--气候--影响。
GMDSS海上无线电业务简答题题库上海海事大学
GMDSS海上无线电业务简答题题库上海海事大学1.请说明下列无线电传通信指令的意义:ga+:请发过来的请求msg+:请对方电台发送电文。
tlxxy+:存贮转发指令。
x:则表示前面提“0”的电传国家码。
y:则表示用户电传号码。
dirtlxxy+:轻易电传指令。
tgm+:用无线电传传达无线电报。
help+:建议对方传送对外开放的业务指令。
brk+:无线拆线,即为通信完结指令。
kkkk:有线拆线指令。
2.简述用arq方式下的船到岸电传通信程序.电传通信之前,船台应当在原订的岸台发送频率上,采用nbdp设备和岸台的mmsi或四位选呼码应答电台。
1输入岸台mmsi或四位选呼码,启动呼叫2简历通信并交换应答码3海岸电台发ga+4船台传送电传业务指令,如dirtlx+5海岸电台播发mom,恳请船台稍等6海岸电台播发用户接收者码点和msg+7船台TE120已编辑不好的电文8船台与陆地用户互换接收者码9船台发送kkkk拆除有限,保留无线线路10船岸电台交换应答码11海岸电台传送“电传计费时间”等信息12海岸电台传送“ga+”13如果除了电文必须传送,船台可以从第四步已经开始重复,如果没,传送brk+,拆毁无线线路,完结通信。
3.如何用dsc呼叫建立ssb海上无线电话通信。
1.船台应答岸台(船台)的操作程序1将收发信机谐波至适度的dsc频率上2编辑dsc电文---格式符(单呼)---地址(mmsi)---挑选类别(常规或船舶业务)---挑选随后的通信方式(j3e或f3e/g3e或f1baqr 或f1bfec)----随后的工作频率(道)----如果是呼叫另一船台,应指明要求通信的频率或频道,如果是呼叫岸台,不应指明要求通信的频率或频道,而一般由岸台在其dsc确认中指明一个空闲的工作频道)---序列终止符(通常为rq)3挑选dsc应答频率,在证实应答频率上没其它的dsc应答后,展开dsc应答。
(dsc控制器能遥控收发信机,完成收发频率和工作模式的正确设置,并能自动调谐。
海上无线电 GMDSS 习题集汇总
一、选择题1.无线电波的传播可划分为()种传播方式。
A. 2B. 3C. 4D. 52. 在无线电波的几种传播方式中,最稳定可靠的是()传播。
A. 天波B. 地波C. 空间波D.电离层波3. 以下最适合以地波进行传播的是()波段信号。
A.长波B. 中波C. 短波D. 超短波4. 以下最适合以空间波进行传播的是()波段信号。
A.长波B. 中波C. 短波D. 超短波5. 以下最适合以天波进行传播的是()波段信号。
A.长波B. 中波C. 短波D. 超短波6. 在GMDSS中,中频的工作频率范围是()。
A. 1.6-4MHzB. 4.0-27.5MHzC. 30-60MHzD. 156-174MHz7. 在GMDSS中,高频的工作频率范围是()。
A. 1.6-4MHzB. 4.0-27.5MHzC. 30-60MHzD. 156-174MHz8. 在GMDSS中,甚高频的工作频率范围是()。
A. 1.6-4MHzB. 4.0-27.5MHzC. 30-60MHzD. 156-174MHz9. 无线电通信系统中,一般有()调制方式。
A.调幅B. 调频C. 调相D. A、B、C都是。
10. 对调幅、单边带、调频无线电话通信的带宽作比较,应是()。
A. 调幅>单边带>调频B. 调频>单边带>调幅C. 调幅>调频>单边带D. 调频>调幅>单边带11. 单边带接收机中,从中频信号中还原音频信号所应采用的电路是()。
A. 幅度检波器B. 同步(乘积)检波器C. 鉴频器D. 鉴相器12. GMDSS的首要功能是()。
A、日常通信B、播发海上安全信息C、驾驶台与驾驶台通信D、遇险船舶的可靠通信13.GMDSS的遇险报警至少包含的信息是()。
A、船位B、船舶的识别C、船舶的遇险时间D、A和B14.GMDSS设备的配备是按()要求进行的。
A、船舶吨位B、各国配备规范C、船舶航区D、船舶动力装置的功率15.海上安全信息播发系统,由系统()组成。
GMDSS设备课后问答题 整理版
本提纲为航海1417 白兴超整理,仅供航海1417-141C班适用。
以下所有简答题是老师划的重要简答题以及个人认为重要的题目。
仅供参考复习,如有异议,请指出,谢谢第1章1.原海上通信系统与GMDSS相比存在哪些局限性?1)可靠通信距离近2)需要经过专门训练的报务员才能适任海上遇险报警与通信3)报警设备的自动化和可靠性能差,受人为因素影响大4)远距离报警手段单一,全球覆盖能力差5)对遇险船舶的搜救缺乏有效的国际协调与合作6)常规通信手段落后,通信自动化程度低2.简述GMDSS的基本含义。
GMDSS是从何时开始全面实施的?GMDSS全称为global maritime distress and safety system,就是全球海上遇险与安全系统的缩写。
该系统主要由卫星通信系统—INMARSAT (海事卫星通信系统) 和COS-PAS/SARSAT(极轨道卫星搜救系统)、地面无线电通信系统(即海岸电台)以及海上安全信息播发系统三大部分构成。
1999年2月1日。
3.GMDSS主要有哪些功能?(1)遇险报警,三个方向;(2)搜救协调通信;(3)救助现场通信;(4)救助现场寻位;(5)海上安全信息(MSI)的播发与接收;(6)快捷高效的常规通信;(7)驾驶台对驾驶台通信;4.GMDSS现场寻位功能是怎样实现的?(1)Radar-SART:通过遇险目标携带的搜救雷达应答器SART和救助船或飞机上的X波段雷达所构成的寻位系统实现。
当遇险目标携带的Radar-SART被救助船或飞机上的X波段雷达信号触发时,救助船或飞机上的雷达屏幕就会显示出遇险目标的相对位置,从而迅速发现遇险目标,达到及时救助的目的。
(2)AIS-SART:当船舶遇险时,开启AIS-SART,会在AIS的专用信道上自动发射遇险报警信息,主要包括遇险船的位置和识别码等信息,周围船舶收到该特殊信息后,可以很快确定遇险船舶的位置,从而便于救援人员对遇险目标进行迅速准确的定位,并实现及时救助。
船舶无线电基础习题答案
船舶无线电基础习题答案船舶无线电基础习题答案船舶无线电通信是航海中不可或缺的一部分,它承担着船舶与陆地、其他船舶之间的通信任务。
为了确保船舶无线电通信的顺利进行,船舶无线电基础知识的掌握是必不可少的。
下面将针对一些常见的船舶无线电基础习题进行解答,帮助读者更好地理解和掌握相关知识。
1. 什么是VHF无线电通信?VHF无线电通信是指在频率范围为30MHz至300MHz之间进行的无线电通信。
在船舶上,VHF无线电通信主要用于短距离通信,如船舶与附近海岸、其他船舶之间的通信。
2. 什么是GMDSS系统?GMDSS(全球海上遇险和安全系统)是国际海事组织(IMO)制定的一套全球海上通信和导航系统,旨在提高船舶遇险时的求救效率和航海安全水平。
它包括多种通信设备,如卫星通信设备、VHF无线电设备等。
3. 如何使用VHF无线电呼叫其他船舶?使用VHF无线电呼叫其他船舶时,首先要设置正确的工作频率和呼叫方式。
然后,按下PTT(Push To Talk)按钮,说出船舶的名称和自己的呼号。
等待对方回应后,进行正常的通话。
4. 如何使用VHF无线电进行紧急呼叫?在紧急情况下,使用VHF无线电进行呼叫时,首先要选择正确的紧急频道(通常为频道16)。
然后,按下PTT按钮,说出“MAYDAY”(表示紧急求救)并重复三次,接着说明船舶的名称、位置、遇险情况和请求的帮助。
5. 如何进行VHF无线电通信的监听?进行VHF无线电通信的监听时,应选择正确的工作频率,并将接收器调至相应频率。
同时,要确保接收器的音量调节适中,以免错过重要的通信信息。
6. 什么是EPIRB?EPIRB(紧急位置指示无线电信标)是一种用于发射紧急信号的设备,主要用于船舶遇险时的求救。
它能够通过卫星定位系统(如GPS)确定船舶的位置,并发出求救信号,以便救援人员能够及时找到遇险船舶。
7. 如何使用EPIRB进行求救?使用EPIRB进行求救时,首先要确保EPIRB的电源开关打开,并将其放置在船舶上易于寻找的位置。
海上无线电通信业务阅读习题集
Marine Radio Communication ServiceExercise BookletZhou fengShanghai Maritime UniversitySection-A: General Information and System Overview. Key Topic #1: Fundamental Concepts:1A1 What is the fundamental concept of the GMDSS?A. GMDSS utilizes automated systems and satellite technology to improve emergency communications for the world’s shipping industry.B. It is intended to automate and improve existing digital selective calling procedures and techniques.C. It is intended to provide more effective but lower cost commercial communications.D. It is intended to provide compulsory vessels with a collision avoidance system when they are operating in waters that are also occupied by non-compulsory vessels.1A2 The primary purpose of the GMDSS is:A. Allow more effective control of SAR situations by vessels.B. Automate and improve emergency communications for the world's shipping industry.C. Provide additional shipboard systems for more effective company communications.D. Effective and inexpensive communications.1A3 What is the basic concept of GMDSS?A. Shoreside authorities will rely on reports from nearby vessels to become aware of Distress alerts.B. Shoreside authorities and vessels can assist in a coordinated SAR operation only after the correct chain of DSC relays takes place.C. SAR authorities ashore can be alerted to a Distress situation & shipping in the vicinity can be requested to participate in SAR operations.D. SAR authorities ashore wait to have EPIRB Distress alerts confirmed by satellite follow-on communications.1A4 GMDSS is primarily a system based on:A. Ship-to-ship Distress communications using MF or HF radiotelephony.B. VHF digital selective calling from ship to shore.C. Distress, Urgency and Safety communications carried out by the use of narrow-band direct printing telegraphy.D. The linking of search and rescue authorities ashore with shipping in the immediate vicinity of a ship in Distress or in need of assistance.1A5 What is the responsibility of compulsory GMDSS vessels?A. Every vessel must be able to perform communications functions essential for its own safety and the safety of other vessels.B. Vessels must transmit a DSC distress relay upon receipt of a DSC distress alert.C. Only the vessels closest to a Distress incident must render assistance.D. Vessels must immediately acknowledge all DSC distress alerts.1A6 GMDSS is required for which of the following?A. All vessels capable of international voyages.B. SOLAS Convention ships of 300 gross tonnage or more.C. Vessels operating outside of the range of VHF coast radio stations.D. Coastal vessels of less than 300 gross tons.Answers - 1A1 - A 1A2 - B 1A3 - C 1A4 - D 1A5 - A 1A6 - BSection-A: General Information and System Overview. Key Topic #2: Equipment Systems:2A1 Which GMDSS system utilizes terrestrial radio techniques?A. F-77B. Inmarsat-CC. GPSD. VHF-MF-HF-DSC2A2 What equipment utilizes satellite communications?A. Inmarsat-CB. VHF-MF-HFC. NAVTEXD. SART2A3 What equipment is used in or near the survival craft?A. NAVTEXB. EPIRBC. FathometerD. COSPAS-SARSAT2A4 What equipment is programmed to initiate transmission of Distress alerts and calls to individual stations?A. NAVTEXB. GPSC. DSC ControllerD. DSC Scanning Watch Receiver2A5 What system provides accurate vessel position information to the GMDSS equipment?A. COSPAS-SARSATB. EPIRBC. GPSD. Inmarsat-B2A6 Which of these can be used to receive MSI?A. SARTB. EPIRBC. Inmarsat-BD. NAVTEXAnswers: 2A1 - D 2A2 - A 2A3 - B 2A4 - C 2A5 - C 2A6 - DSection-A: General Information and System Overview. Key Topic #3: Sea Areas:3A1 Which of the following regions lie outside Sea Areas A1, A2, and A3?A. Sea Areas only apply to Inmarsat footprint areas.B. Sea Area A3-I Inmarsat coverage and Sea Area A3-S HF SITOR (NBDP) coverage.C. Sea Area A4D. There are no additional Sea Areas.3A2 What sea area is defined as being within range of a shore-based MF station that provides for continuous DSC alerting?A. Coastal watersB. Sea area A3C. Sea area A1D. Sea area A23A3 If a vessel is engaged in local trade and at no point in its voyage travels outside the range of a VHF shore station with continuous DSC alerting then the vessel is operating in what area?A. Sea area A1B. Coastal and international zonesC. Inland and coastal watersD. Sea areas A1 and A23A4 What is defined as an area, excluding sea areas A1 and A2, within the coverage of an Inmarsat geostationary satellite in which continuous alerting is available?A. Ocean Area Regions AOR-E, AOR-W, POR or IORB. Sea Area A3C. Sea Area A4D. Coastal and Inland Waters3A5 SITOR (NBDP) equipment is a partial or alternate carriage requirement under GMDSS for vessels operating in which sea area(s)?A. A1B. A3 and A4C. A1 and A2D. A1, A2, A3 and A43A6 What is defined as the area within the radiotelephone coverage area of at least one VHF coast station in which continuous DSC alerting is available as defined by the IMO regulation for GMDSS?A. Ocean Area Regions AOR-E, AOR-W, POR or IORB. Sea Area A2C. Sea Area A1D. Coastal and Inland WatersAnswers: 3A1 - C 3A2 - D 3A3 - A 3A4 - B 3A5 - B 3A6 - C4A1 Which of the following is a functional or carriage requirement for compulsory vessels?A. A compulsory vessel must carry at least two (2) FCC licensed GMDSS Radio Operators in all sea areas as well as a GMDSS Maintainer in sea areas A3 & A4.B. A compulsory vessel must satisfy certain equipment carriage requirements based on the intended sea area of operation.C. A compulsory vessel must be able to transmit and respond to Distress alerts and carry only one (1) FCC licensed GMDSS Radio Operator in sea areas A1 & A2.D. None of these answers are correct.4A2 Which GMDSS communication functions must all compulsory vessels be capable of performing to meet International Maritime Organization requirements?A. Distress alerting and receipt of Maritime Safety Information via Inmarsat for all vessels intending to operate in Sea Area A4.B. Distress alerting and receipt of MSI in Sea Areas A1, A2, A3, and A4 regardless of the vessel's intended area of operation.C. Distress alerting, general communications and receipt of Maritime Safety Information in the vessel's intended area of operation.D. General communications via Inmarsat and receipt of Maritime Safety Information via Enhanced Group Calling in Sea Area A4.4A3 GMDSS-equipped ships will be required to perform which of the following communications functions?A. Distress alerting, MSI, SAR and on-scene communications & receipt of satellite alerts from other vessels.B. SAR and on-scene communications, Bridge-to-Bridge and general radio communications, MSI and relay of satellite alerts from other vessels.C. Bridge-to-Bridge and general radio communications, RDF of EPIRB homing signals, Distress alerting and MSI.D. Transmit distress alerts, SAR and on-scene communications, MSI, Bridge-to-Bridge and general radio communications.4A4 What equipment can be used to receive Maritime Safety Information?A. NAVTEX, EGC receiver or HF SITOR (NBDP).B. EGC receiver, Inmarsat B or F77 terminal.C. HF SITOR (NBDP), Inmarsat B or NAVTEX.D. All of these answers are correct.4A5 Which of the following are required GMDSS functions?A. Bridge-to-Bridge communications, reception of weather map facsimile broadcasts, SAR communications.B. Reception of weather map facsimile broadcasts, receiving company email, On-scene communications.C. Reception of VHF weather channels, On-scene communications, general communicationsD. Bridge-to-Bridge communications, general communications, SAR communications.4A6 Which of the following are required GMDSS functions for vessels?A. Transmit and receive locating signals, general communications and SAR communications.B. Transmit and receive general communications, transmit Distress Alerts by at least one means, MSI.C. Transmit and receive locating signals, send MSI to other ships via EGC, Bridge-to-Bridge communications.D. Transmit and receive SAR communications, transmit Distress Alerts by at least one means, Bridge-to-Bridge communications.Answers: 4A1 - B 4A2 - C 4A3 - D 4A4 - A 4A5 - D 4A6 - A5A1 Which statement is true regarding a vessel equipped with GMDSS equipment that will remain in Sea AreaA1 at all times?A. The vessel must be provided with a radio installation capable of initiating the transmission of ship-to-shore Distress alerting from the position from which the ship is normallynavigated. B. VHF DSC alerting may be the sole means of Distressalerting.C. HF or MF DSC may satisfy the equipment requirement.D. HF SSB with 2182 kHz automatic alarm generator may satisfy the equipment requirement.5A2 What statement is true regarding the additional equipment carriage requirement imposed for the survival craft of vessels over 500 gross tons?A. Additional carriage of two radio equipped lifeboatsaft. B. A second radar transponder is required.C. Four additional portable VHF radios are required.D. The ability to communicate in all modes with any shore station.5A3 Vessels operating in which sea area(s) are required to carry either Inmarsat or HF equipmentor a combination thereof under GMDSS?A. All sea areasB. A4C. A3D. A15A4 Within a single sea area, what is the primary reason GMDSS imposes carriage requirements for different radio subsystems?A. Redundancy in duplicating all operational functions in the event of a system failure.B. Different subsystems are required to meet the specific equipment carriage requirements ofnational authorities.C. GMDSS vessels must be equipped to communicate in all modes with coast radio stations.D. The combined capabilities of redundant subsystems mitigate the risk of a single point of failure.5A5 If operating within Ocean Area A1, and outside of NAVTEX coverage, a GMDSS-equipped vesselmust carry:A. Equipment capable of reception of Maritime Safety Information by the Inmarsat enhanced group call system, or HF SITOR (NBDP).B. A GPS receiver.C. Equipment capable of maintaining a continuous DSC watch on 2187.5kHz. D. An Inmarsat-B terminal.5A6 What is the equipment carriage requirement for survival craft under GMDSS?A. At least three SCT units and two SARTs on every cargo ship between 300-500 gross tons and the same on all passenger ships regardless of tonnage.B. At least three SCT units and two SARTs on every passenger ship and cargo ships of 500 gross tonsand upwards.C. At least two radar transponders must be carried on every cargo ship of 300-500 gross tons and tworadar transponders (one for each side) of every passenger ship regardless of tonnage.D. All cargo vessels above 300 gross tons and every passenger ship regardless of tonnage must carry three SCT units and two SARTs.Answers: 4A1 - B 4A2 - C 4A3 - D 4A4 - A 4A5 - D 4A6 - ASection-C: F.C.C. Rules & Regulations: Key Topic #16: License and Personnel Requirements:16C1 Which FCC license meets the requirement to serve as a GMDSS operator?A. General Radiotelephone Operator’s License.B. GMDSS Radio Operator’s LicenseC. Marine Radio Operator’s Permit.D. GMDSS Radio Maintainer’s License.16C2 Which of the following statements 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 GMDSS Radio Operators at all times while at sea and may elect to carry a GMDSS Radio Maintainer as well.C. All communications involving Safety of life at sea must 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 on-board licensed GMDSS Radio Maintainer.16C3 Which FCC license meets the requirements to perform or supervise the performance of at-sea adjustments, servicing, or maintenance which may affect the proper operation of the GMDSS station?A. General Radiotelephone Operator’s License with Shipboard RADAR endorsement.B. Marine Radio Operator’s Permit or GMDSS Maintainer’s license.C. GMDSS Radio Operator’s license or Marine Radio Operator’s Permit.D. GMDSS Operator’s/Maintainer’s license or GMDSS Maintainer’s license.16C4 Which statement is false regarding the radio operator requirements for a GMDSS-equipped ship station?A. Maintaining a record of all incidents connected with the radio-communications service that appear to be of importance to Safety of life at sea is not required.B. One of the qualified GMDSS radio operators must be designated to have primary responsibility for radio- communications during Distress incidents.C. A qualified GMDSS radio operator, and a qualified backup, must be designated to perform Distress, Urgency and Safety communications.D. While at sea, all adjustments or radio installations, servicing or maintenance of such installations that may affect the proper operation of the GMDSS station must be performed by, or under the supervision of, a qualified GMDSS radio maintainer.16C5 Which of the following are personnel, functional, or equipment FCC requirements of the GMDSS?A. One FCC licensed GMDSS radio operator in sea areas A1 & A2, two FCC licensed GMDSS radio operators in sea areas A3 & A4 and equipment carriage based on intended sea area of operations.B. Distress alerting and response, two USCG STCW GMDSS watchstanders, equipment carriage based on intended sea area of operations.C. Equipment carriage reduced for sea areas A3 & A4, Distress alerting and response and two FCC licensed GMDSS radio operators.D. Equipment carriage based on intended sea area of operations, distress alerting and response and two FCC licensed GMDSS radio operators.16C6 How many GMDSS radio maintainers must be carried aboard a compulsory vessel if the At-Sea maintenance method is used?A. One regardless of sea area of operation.B. Two in Sea Areas A3 and A4.C. Two in Sea Area A1.D. None of these answers are correct.Answers: 16C1 - B 16C2 - C 16C3 - D 16C4 - A 16C5 - D 16C6 - ASection-C: F.C.C. Rules & Regulations: Key Topic #16: Reserve Source of Energy:17C1 Which statement is false regarding the GMDSS requirement for ship sources of energy?A. The reserve sources of energy need to supply independent MF and HF radio installations at the same time.B. At all times while the vessel is at sea, a sufficient supply of electrical energy to operate the radio installations and charge any batteries which may be part of the reserve source of energy is required.C. An uninterruptible power supply or other means of ensuring a continuous supply of electrical power to all GMDSS equipment that could be affected by normal variations and interruptions of ship's power is required.D. If a vessel’s position is constantly required for the proper performance of a GMDSS station, provisions must be made to ensure position information is uninterrupted if the ship’s source of main or emergency energy fails.17C2 What is the meaning of “Reserve Source of Energy”?A. High caloric value items for lifeboat, per SOLAS regulations.B. Power to operate the radio installation and conduct Distress and Safety communications in the event of failure of the ship's main and emergency sources of electrical power.C. Diesel fuel stored for the purpose of operating the powered survival craft for a period equal to or exceeding the U.S.C.G. and SOLAS requirements.D. The diesel fueled emergency generator that supplies AC to the vessel’s Emergency power bus.17C3 Which term describes the source of energy required to supply the GMDSS console with power if the ship’s source of main or emergency energy fails?A. Emergency powerB. Ship's emergency diesel generatorC. Reserve Source of EnergyD. Ship's standby generator17C4 What characteristics describe the GMDSS Reserve Source of Energy (RSE)?A. Supplies independent HF and MF installations at the same time.B. Cannot be independent of the propelling power of the ship.C. Must be incorporated into the ship's electrical system.D. Must be independent of the ship's electrical system when the RSE is needed to supply power to the GMDSS equipment.17C5 What is the requirement for emergency and reserve power in GMDSS radio installations?A. Compulsory ships must have emergency and reserve power sources for radio communications.B. An emergency power source for radio communications is not required if a vessel has proper reserve power (batteries).C. A reserve power source is not required for radio communications.D. Only one of the above is required if a vessel is equipped with a second 406 EPIRB as a backup means of sending a Distress alert.17C6 Which of the following terms is defined as a back-up power source that provides power to radio installations for the purpose of conducting Distress and Safety communications when the vessel's main and emergency generators cannot?A. Emergency Diesel Generator (EDG)B. Reserve Source of Energy (RSE)C. Reserve Source of Diesel Power (RSDP)D. Emergency Back-up Generator (EBG)Answers: 17C1 - A 17C2 - B 17C3 - C 17C4 - D 17C5 - A 17C6 - BSection-C: F.C.C. Rules & Regulations: Key Topic #18: Equipment Testing:18C1 Under GMDSS, a compulsory VHF-DSC radiotelephone installation must be tested at what minimum intervals at sea?A. Annually, by a representative of the FCC.B. At the annual SOLAS inspection.C. MonthlyD. Daily18C2 Which statement concerning the testing of a compulsory radiotelephone station is false?A. Calling the USCG on VHF CH-16 or 2182.0 kHz is the most effective method.B. Tests may be accomplished by using the equipment for normal business.C. A daily test is necessary unless the equipment was used for routine traffic.D. The test may not interfere with communications in progress and must wait or be suspended if a request to do so is made.18C3 While underway, how frequently is the DSC controller required to be tested?A. Once a weekB. Once a dayC. Twice a weekD. Once a month18C4 At sea, all required equipment (other than Survival Craft Equipment) must be proven operational by:A. Testing at least every 48 hours.B. Weekly testing of all S.C.E. and other compulsory equipment.C. Daily testing or daily successful use of the equipment.D. Daily testing of the S.C.E. and weekly tests of the other equipment.18C5 The best way to test the MF-HF SITOR (NBDP) system is:A. Make a radiotelephone call to a coast station.B. Initiate an ARQ call to demonstrate that the transmitter and antenna are working.C. Initiate an ARQ call to a Coast Station and wait for the automatic exchange of answerbacks.D. Initiate an FEC call to demonstrate that the transmitter and antenna are working.18C6 The best way to test the Inmarsat-C terminal is:A. Send a message to a shore terminal and wait for confirmation.B. Send a message to another ship terminal.C. If the “Send” light flashes, proper operation has been confirmed.D. Compose and send a brief message to your own Inmarsat-C terminal.Answers: 18 - D 18C2 - A 18C3 - B 18C4 - C 18C5 - C 18C6 - D19C1 A vessel certified for service in Sea Area A3 is required to maintain a watch on:A. VHF Channel 70, MF Frequency 2182.0 kHz, HF on 8414.5 kHz and one other HF DSC frequency.B. MF Frequency 2187.5 kHz, HF on 8414.5 kHz and one other HF DSC frequency, HF on 4125.0 kHz.C. VHF Channel 70, MF Frequency 2187.5 kHz, HF on 8414.5 kHz and one other HF DSC frequency.D. VHF Channel 16, VHF Channel 70, MF Frequency 2187.5 kHz, HF on 8414.5 MHz and HF 4177.5 MHz.19C2 A vessel certified for service in Sea Area A-2 is required to maintain watch on:A. 2174.5 kHzB. 2182.0 kHzC. 2738.0 kHzD. 2187.5 kHz19C3 What are the mandatory DSC watchkeeping bands/channels?A. 8 MHz HF DSC, 1 other HF DSC, 2 MHz MF DSC and VHF Ch-70.B. 2 MHz MF DSC, 8 MHz DSC, VHF Ch-16 and 1 other HF DSC.C. VHF Ch-70, 2 MHz MF DSC, 6 MHz DSC and 1 other HF DSC.D. VHF Ch-70, 2 MHZ MF DSC, 4 MHZ DSC and 8 MHz DSC.19C4 Proper watchkeeping includes the following:A. Monitoring all required frequencies in the proper mode, setting the DSC scanner to 2 MHz, 4 MHZ and 8 MHz for ships in the vicinity, notifying the Master of any Distress alerts.B. After silencing an alarm all displays and/or printouts are read, monitoring all required frequencies in the proper mode, notifying the Master of any Distress alerts.C. Notifying the Master of any Distress alerts, setting the DSC scanner to 2 MHz, 4 MHZ and 8 MHz for ships in the vicinity, monitoring all required frequencies in the proper mode.D. Setting the DSC scanner only to the mandatory 2 MHz & 8 MHz, maintain continuous watch on 2182.0 kHz or 4125.0 kHz, notify the Master of any Distress traffic heard.19C5 Proper watchkeeping includes the following:A. Understanding normal operational indicators, setting the DSC scanner frequencies to minimize alarms, maintaining a proper log.B. Maintaining a proper GMDSS radio station log, understanding normal operational indicators, responding to and comprehending alarms.C. Responding to and comprehending alarms, logging out of Inmarsat-C terminals while at sea, maintaining a proper GMDSS radio station log.D. Maintaining a proper GMDSS radio station log, setting the DSC scanner frequencies to minimize alarms, logging out of Inmarsat-C terminals while at sea.19C6 Which is true concerning a required watch on VHF Ch-16?A. When a vessel is in an A1 sea area and subject to the Bridge-to-Bridge act and in a VTS system, a watch is required on Ch-16 in addition to both Ch-13 and the VTS channel.B. It is not compulsory at all times while at sea until further notice, unless the vessel is in a VTS system.C. When a vessel is in an A1 sea area and subject to the Bridge-to-Bridge act and in a VTS system, a watch is not required on Ch-16 provided the vessel monitors both Ch-13 and the VTS channel.D. It is not always compulsory in sea areas A2, A3 and A4.20C1 Which of the following statements meets requirements for 47 CFR 80 Subpart-W?A. GMDSS Radio Logs may not be retained aboard compulsory vessels in an electronic file (e.g., word processing) format.B. GMDSS Radio Logs must contain entries of all Distress and Urgency communications affecting your own ship.C. GMDSS Radio Logs must be retained aboard compulsory vessels for a period of at least 90 days in their original form.D. Entries in the GMDSS Radio Log are only required for communications within the vessel's intended Sea Area of operation.20C2 Which of the following statements is false?A. Key letters or abbreviations may be used in GMDSS Radio Logbooks if their meaning is explained.B. Urgency communications may need to be entered in the GMDSS radio log.C. Distress communications heard do not require entries if the vessel did not participate in SAR activity.D. Log entries of VHF Safety broadcasts are not required.20C3 Where should the GMDSS radio log be kept on board ship?A. Captain's officeB. Sea cabinC. Anywhere on board the vessel.D. At the GMDSS operating position.20C4 How long must the radio log be retained on board before sending it to the shoreside licensee?A. At least 30 days after the last entry.B. At least one year after the last entry.C. At least two years after the last entry.D. At least 90 days after the last entry.20C5 Which statement concerning radio log archival by the station licensee is false?A. Retain for two years if there are no Distress entries.B. Logs related to an investigation may not be destroyed without specific authorization.C. Retain for three years if there are Distress entries.D. Retain for one year unless there are Distress or Urgency entries.20C6 Which of the following logkeeping statements is false?A. Entries of all company communications using GMDSS satellite equipment are required.B. Entries relating to pre-voyage, pre-departure and daily tests are required.C. A summary of all Distress communications heard and Urgency communications affecting the station’s own ship. Also, all Safety communications (other than VHF) affecting the station’s own ship must be logged.D. Entries related to failures of compulsory equipment are required.Section-D: DSC & Alpha-Numeric ID: Key Topic #21: Call Signs and SELCALs21D1 A typical call sign for a large container ship under Chinese Flagwould be:A. KBZYB. WBX1469C. NADND. KPH21D2 What would the number 1090 indicate?A. A ship DSC MMSI number.B. A coast station SITOR (NBDP) SELCAL number.C. A coast station DSC MMSI number.D. A ship station SITOR (NBDP) SELCAL number.21D3 Which one of the following is a ship station SELCAL?A. 1104B. 1502352C. 11243D. 023*******21D4 Which of the following is the call sign for a U.S.C.G. coast station?A. NERKB. KPHC. WCCD. NMN21D5 What type of station would be assigned the call sign WAB2174?A. Tug boatB. Container shipC. Passenger shipD. Bulk Tanker21D6 What number will a ship station use to identify itself using SITOR (NBDP)?A. Four digit SELCAL.B. Five digit SELCAL or 9 digit SELCAL number identical to MMSI.C. 9 digit Inmarsat-B I.D. number.D. 9 digit Inmarsat-C I.D. number.Answers: 21D1 - A 21D2 - B 21D3 - C 21D4 - D 21D5 - A 21D6 - BSection-D: DSC & Alpha-Numeric ID: Key Topic #22: MMSI- MID and Ship Station I.D. Numbers: 22D1 What is the MID?A. Mobile Identification NumberB. Marine Indemnity DirectoryC. Mobile Interference DigitsD. Maritime Identification Digits22D2 How many digits are in the MID (Maritime Identification Digits)?A. 3B. 7C. 9D. 1022D3 What does the MID (Maritime Identification Digits) signify?A. Port of registryB. NationalityC. Gross tonnageD. Passenger vessel22D4 Which of the following numbers indicates a CHINA flag shipstation?A. 036627934B. 243537672C. 412426791D. 00338231522D5 Which of the following MMSI numbers indicates a CHINA flag shipstation?A. 412326890B. 033609991C. 303236824D. 25732681922D6 Which of the following numbers indicates a ship station MMSI?A. 003372694B. 030356328C. 3384672D. 623944326Section-D: DSC & Alpha-Numeric ID: Key Topic #23: MMSI; Group and Coast Station I.D. Numbers:23D1 A DSC call is received from a station with a MMSI number of 003669991. What type of station made the call?A. A vessel operating in Sea Area A3.B. A group ship stationC. A China. coast stationD. An Intercoastal vessel23D2 A valid MMSI number for a DSC call to a specific group of vessels is:A. 003664523B. 338462941C. 003036483D. 03032793123D3 A MMSI 030346239 indicates what?A. Group MMSIB. Inmarsat-C I.D. numberC. Coast stationD. Ship station23D4 Which of the following statements concerning MMSI is true?A. Coast station MMSI numbers have 9 digits starting with 4.B. All MMSI numbers are 9 digits and contain an MID.C. Ship station MMSI numbers can be 7 digits or 9 digits depending on the Inmarsat terminal.D. Group MMSI numbers must begin with 2 zeros.23D5 Which of the following statements concerning MMSI is false?A. All Coast Station MMSI must begin with 2 zeros.B. All Coast Station MMSI must begin with the MID then 2 zeros.C. A group call must begin with a single zero followed by the MID.D. The first 3 digits of a ship MMSI comprise the MID.23D6 Which of the following statements concerning MMSI is true?A. All ship station MMSI must begin with a single zero and include the MID.B. All group station MMSI must begin with the MID.C. None of these answers are correct.D. All Coast Station MMSI must be 9 digits and begin with the MID and then two zeros.。
上海海事大学《船舶无线电业务》作业大题
《船舶无线电业务》作业大题(有缺漏请自行补充)1、MMSI的组成船舶电台的水上移动通信业务标识(MMSI)由以下九位数字构成:MIDX4X5X6X7X8X9其中MID,代表分配给每一个国家或地区的水上识别数字;X4至X9中的任意一个数字。
船台群呼标识码:船台群呼标识码的格式如下:0MIDXXXXX江、海岸电台标识码和江、海岸电台群呼标识码00MIDXXXX2、ARQ工作方式的主要特点要求通信双方的的两个电台的收发信机同时工作。
这种通信方式一般适用于两个电台之间的通信。
FEC即前向纠错工作方式是NBDP通信中另一种主要的通信方式,FEC要求收发方以单频方式工作,当采用FEC方式时,接收电台不需启动发信机。
其中CFEC方式适用于某电台向所有其他台播发通播信息时采用,如海上遇险、紧急与安全信息的发送就是采用这种方式进行的。
SFEC则适用于接收台是一个或具有某特征的一组台.值得注意的是,采用FEC发送信息时,起始呼叫至少应持续10秒,并至少应发送一个回车信号和一个换行信号。
4、船到岸的ARQ通信程序如下1)船舶电台呼叫海岸电台:输入岸台MMSI或四位选呼码,启动呼叫;2)建立通信并自动交换应答码;3)海岸电台发GA+;4)船台发送电传业务指令,如DIRTLX…+;5)海岸电台发MOM,请船台稍等;6)海岸电台发用户应答码和MSG+;7)船台调发已编辑好的电文;8)船台与陆地用户交换应答码;9)船台发送KKKK,拆除有线,保留无线线路;10)船岸电台之间交换应答码;11)海岸电台发送“电传计费时间”等信息;12)海岸电台发送GA+;13)如果还有电文要发送,船台可以从第4)步开始重复;如果没有,发送BRK+,拆除无线线路,结束通信。
5、人工DSC呼叫和确认操作程序1、船台呼叫岸台或另一船台:1)首先将收发信机调谐到适当的DSC频率上;2)根据设备使用说明书,按以下序列编辑DSC电文:—— 格式符(selective/all ships/group/area))—— 输入海岸电台或另一船台的MMSI码;—— 选择类别(常规或船舶业务);—— 选择随后的通信方式(RT/ARQ/FEC));—— 如果是呼叫另一船台,应指明要求通信的频率或频道,如果是呼叫岸台,不应指明要求通信的频率或频道,而一般由岸台在其DSC确认中指明一个空闲的工作频道;3)在确认呼叫频率上没有其它的DSC呼叫后,船舶电台操作员可进行DSC呼叫。
大连海事通信考研真题答案
大连海事通信考研真题答案一、导论题1. 解决通信问题是海事工作的重要任务之一。
请问,在海洋环境中所采用的通信方式有哪几种,各有什么特点?答:在海洋环境中,常用的通信方式包括无线电通信、卫星通信和光纤通信。
无线电通信是一种基于电磁波传输的通信方式,具有传输距离远、传输速率快、适应性强等优点。
它可以通过调频、调幅等方式实现语音和数据的传输。
卫星通信利用人造地球卫星作为中继站,将信号从发射站发送到接收站。
它具有广播范围广、覆盖范围广和传输速度快等特点,适合大范围的通信需求。
光纤通信利用光纤传输信息,具有传输速度快、传输损耗低和抗干扰能力强等优点。
它适用于海底通信等高要求的环境,并且能够支持大数据传输。
二、无线电通信题2. 请简述无线电通信中的频率调制技术以及各种调制方法的应用场景。
答:频率调制(Frequency Modulation,FM)是指通过改变载波信号的频率来传输信息的技术。
常见的调制方法有调频(FrequencyModulation,FM)、调幅(Amplitude Modulation,AM)和调相(Phase Modulation,PM)。
调频:调频广播就是通过改变载波信号频率的方式来传输音频信息的。
它能够提供较好的音质,且对抗干扰的能力较强,所以在广播领域得到了广泛应用。
调幅:调幅广播是通过改变载波信号的振幅来传输音频信息的。
它的信号传输距离较远,适用于广播范围较大的场景,但对干扰的抵抗能力相对较差。
调相:调相是通过改变载波信号的相位来传输信息的。
它的特点是传输稳定,适用于信号传输质量要求较高的场合,如航空通信和卫星通信等。
三、卫星通信题3. 请简述卫星通信中的极地轨道和地球同步轨道的特点及其应用领域。
答:极地轨道是一种接近于北极和南极的轨道,它的特点是轨道平面与地球自转轴的夹角较小。
极地轨道卫星的特点是传输范围广、穿越时间短,适用于偏远地区通信和气象观测等领域。
地球同步轨道是一种与地球自转同步的轨道,它的特点是卫星的周期与地球自转周期相等。
海上无线电 GMDSS 习题集
一、选择题1.无线电波的传播可划分为()种传播方式。
A. 2B. 3C. 4D. 52. 在无线电波的几种传播方式中,最稳定可靠的是()传播。
A. 天波B. 地波C. 空间波D.电离层波3. 以下最适合以地波进行传播的是()波段信号。
A.长波B. 中波C. 短波D. 超短波4. 以下最适合以空间波进行传播的是()波段信号。
A.长波B. 中波C. 短波D. 超短波5. 以下最适合以天波进行传播的是()波段信号。
A.长波B. 中波C. 短波D. 超短波6. 在GMDSS中,中频的工作频率范围是()。
A. 1.6-4MHzB. 4.0-27.5MHzC. 30-60MHzD. 156-174MHz7. 在GMDSS中,高频的工作频率范围是()。
A. 1.6-4MHzB. 4.0-27.5MHzC. 30-60MHzD. 156-174MHz8. 在GMDSS中,甚高频的工作频率范围是()。
A. 1.6-4MHzB. 4.0-27.5MHzC. 30-60MHzD. 156-174MHz9. 无线电通信系统中,一般有()调制方式。
A.调幅B. 调频C. 调相D. A、B、C都是。
10. 对调幅、单边带、调频无线电话通信的带宽作比较,应是()。
A. 调幅>单边带>调频B. 调频>单边带>调幅C. 调幅>调频>单边带D. 调频>调幅>单边带11. 单边带接收机中,从中频信号中还原音频信号所应采用的电路是()。
A. 幅度检波器B. 同步(乘积)检波器C. 鉴频器D. 鉴相器12. GMDSS的首要功能是()。
A、日常通信B、播发海上安全信息C、驾驶台与驾驶台通信D、遇险船舶的可靠通信13.GMDSS的遇险报警至少包含的信息是()。
A、船位B、船舶的识别C、船舶的遇险时间D、A和B14.GMDSS设备的配备是按()要求进行的。
A、船舶吨位B、各国配备规范C、船舶航区D、船舶动力装置的功率15.海上安全信息播发系统,由系统()组成。
GMDSS业务复习题
GMDSS业务复习题一、英文缩写解释P309-312二、简答题1、什么是海上移动业务识别码、水上数字识别码?各种海上移动业务识别码有什么特点?答:1)海上数字识别码(MMSI):是一种九位识别码,主要分配给船舶电台和海岸电台在DSC和NBDP通信中相互识别身份时使用;2)水上数字识别码(MID):是国际电信联盟给每一个国家分配的水上业务识别码,用来表示海岸电台、船舶电台所属的国家或地区;3)海上移动业务识别码的特点是:①船台选呼:MIDX1X2X3X4X5X6②船台群呼:0MIDX1X2X3X4X5③岸台选呼:00MIDX1X2X3X42、海岸电台、船舶电台、陆地用户的NBDP应答码是如何构成的?答:1)海岸电台:NBDP识别码+岸台呼号(名称缩写)+国际代码2)船舶电台:NBDP识别码+船台呼号+X3)陆地用户:识别码+公司识别+国际代码3、什么是电台呼号?船舶电台、海岸电台呼号是如何组成的?答:1)电台呼号:由无线电管理部门指配给无线使用者唯一的身份证明。
2)呼号组成:①船舶电台:两个字符和两个字母或两个字符、两个字母和一位数字(数字0或1除外)②海岸电台:两个字符和一个字母或两个字符和一个字母,后跟不超过三位数字(紧接在字母后面的数字0或1除外)4、什么事通报表?通报表是如何发出的?答:1)通报表:当陆地用户通过地面系统的无线电话、NBDP及无线电报通信方式联系船舶电台时,在自动连接失败或者不可获得的情况下,海岸电台经常把被叫船舶的船名、呼号按照字母顺序登记在特定的表格里,每天向海上广播,希望表格内的电台主动联系海岸电台,经过海岸电台与陆上用户通信,这样的表格就是通报表。
2)通报标的发出:通报表的播发,应该在特定的、主管部门认可的、固定的时间进行。
一般来讲,时间间隔大于2h,小于4h。
5、简述Imarsat-C系统电传/文本传真/低速数据业务/船至船通信业务的通信程序。
答:Imarsat-C系统电传/文本传真/低速数据业务/船至船通信业务的通信程序如下:1)确认C船站已处于“入网(log-in)”状态;2)在船站电传终端上准备报文,并存储;3)进行发射参数设置;4)启动发射;5)稍后查看发射或呼叫记录,了解地面真是否转发成功。
海上无线电通信设备及业务试卷A卷+答案
学年度第一学期期末考试《海上无线电通信设备及业务》(八)卷专业班级姓名学号一、单选题(每题的备选答案中只有一个量佳答案,每题2分,共30分)【、下列几种情况中会产生电磁波的是()A.用电锯锯铝材时迸出火花B.用声纳探测海底时接收到海底反射来的波C.敲击音叉时,音叉高速振动D.微波炉产生微波2、太阳发出可见光的同时还发射出其他频率的电磁波,这些电磁波在射向地球时波长、频率都不同,所以它们的波速().A.频率高的电磁波波速大8.一样大C.波长长的电磁波波速大D.由于速度=波长X频率,波长、频率不一定,所以无法判断3、电视台发射出•列波长为10米的无线电波,则它的频率大约是()A.30赫兹B.30千赫C.30兆赫D.无法计算4、用声纳探测海底时,已知海水深度为1531米,从发出信号到接收到信号共用了2s,在2s内声波共振动2x10”求所用声纳发出超声波的波长为()A、约1.53χ1.0''米B、约7.66x10'米C、约3.83x10'米D、约1.53x10”米5、无线电的发射与接收装置中的调谐版,其作用是()。
A.产生高频率振荡电流B,使高频率电流随声音信号变化C.得到所需要的带有声音信号的高频率振荡电流D.把信号还原成声音6、一列波在4秒内传播了400米,已知它的波长为10厘米,在这4秒钟内这列波共振荡了()次。
A.1000次B.40次C.1000次D.10次7、无线电干扰大致可分为()级。
Λ.3级B.4级C5级D.6级8、在GSM基站测试中,测得某发射机的工作频率为950.200MHz,该发射机工作在()信道.A.86B.76C.66D.969、当外界存在一个很强的干扰信号,由于收信机的非线性仍能造成对有用信号增益的降低(受到抑制)或噪声提高,使接收机灵敏度下降,这种干扰称为<)干扰。
A.同频道B.邻道C.杂散辐射D.阻塞10、19世纪60年代,英国物理学家()在总结前人研究电磁现象成果的基础上,建立了完整的电磁场理论。
GMDSS简答题
1.试述MF/HF SSB发射机的三次搬频,高中频方案。
答:1)将△F=1.4MHZ与第一载频fc1进行双边带调制,经边带滤波后取下边带,得到fc1-△F下边带信号,然后进行第一次混频,本振频率为fc2=43.6MHZ。
第二次混频,本振频率为fc3=45~75MHZ,混频后取相减的频率分量,得到频率为(45~75)-(45-△F)=0~30mhz+△F的上边带信号。
2)发射机第一载频为1.4MHZ,经边带滤波器选取下边带;第二载频为43.6MHZ,带通滤波器选取和频,得到工作频率为45MHZ的下边带;第三载频为45~75MHZ,滤波器选取差额,输出为0~30MHZ 的上边带。
把第二混频器的输入频率成为中间频率,它高于输出的最高工作频率,这种中间频率高于发射机最高工作频率的方案,称为“高中频”方案。
2.简述406MHz EPIRB遇险报警的路由。
答:406MHZ的无线电示位标发出的遇险报警信号被COSPSA\SARSAT 卫星接受处理,处理后的信号在1544.5MHZ卫星下行线路频率上转发给陆上的LUT。
LUT对信号进行处理,算出示位标的位置,连同信标的其他遇险信息一起由MCC发送给RCC。
RCC经国际通信网络通知遇险地区的相关搜救部门,由RCC组织、指挥搜救工作。
3.试述船舶GMDSS无线电人员的资格证书等级及业务范围。
答:证书等级:一级无线电电子证书、二级无线电电子证书、通用操作员证书、限定操作员证书。
试用范围:①一级无线电电子证书和二级无线电电子证书试用于A1、A2、A3、A4海区航行的船舶、海上平台或设施。
②通用操作员证书适用于A1、A2海区航行的船舶、海上平台或设施;A3、A4海区航行的双套设备配备的船舶、海上平台或设施。
③限定操作员证书适用于A1海区航行的船舶、海上平台或设施。
4.如何由SART来判别是否有救助船前来救助?答:(1)SART启动、工作处于接收状态时,没有声响。
接收到询问信号时,发出声响;而且当雷达离SART较远时,只有RADAR 天线指向SART,SART应答才发出声响;当距离逐渐变近时,雷达波旁瓣也能询问SART,SART发出的声响逐渐变成连续;(2)SART 的发光指示装置:SART 处于接收状态时,指示灯以2s为一个周期闪0.5s停1.5s。
上海海事大学船舶无线电业务作业大题
《船舶无线电业务》作业大题(有缺漏请自行补充)1、MMSI的组成船舶电台的水上移动通信业务标识(MMSI)由以下九位数字构成:MIDX4X5X6X7X8X9其中MID,代表分配给每一个国家或地区的水上识别数字;X4至X9中的任意一个数字。
船台群呼标识码:船台群呼标识码的格式如下:0MIDXXXXX江、海岸电台标识码和江、海岸电台群呼标识码00MIDXXXX2、ARQ工作方式的主要特点要求通信双方的的两个电台的收发信机同时工作。
这种通信方式一般适用于两个电台之间的通信。
FEC即前向纠错工作方式是NBDP通信中另一种主要的通信方式,FEC要求收发方以单频方式工作,当采用FEC方式时,接收电台不需启动发信机。
其中CFEC方式适用于某电台向所有其他台播发通播信息时采用,如海上遇险、紧急与安全信息的发送就是采用这种方式进行的。
SFEC则适用于接收台是一个或具有某特征的一组台.值得注意的是,采用FEC发送信息时,起始呼叫至少应持续10秒,并至少应发送一个回车信号和一个换行信号。
4、船到岸的ARQ通信程序如下1)船舶电台呼叫海岸电台:输入岸台MMSI或四位选呼码,启动呼叫;2)建立通信并自动交换应答码;3)海岸电台发GA+;4)船台发送电传业务指令,如DIRTLX…+;5)海岸电台发MOM,请船台稍等;6)海岸电台发用户应答码和MSG+;7)船台调发已编辑好的电文;8)船台与陆地用户交换应答码;9)船台发送KKKK,拆除有线,保留无线线路;10)船岸电台之间交换应答码;11)海岸电台发送“电传计费时间”等信息;12)海岸电台发送GA+;13)如果还有电文要发送,船台可以从第4)步开始重复;如果没有,发送BRK+,拆除无线线路,结束通信。
5、人工DSC呼叫和确认操作程序1、船台呼叫岸台或另一船台:1)首先将收发信机调谐到适当的DSC频率上;2)根据设备使用说明书,按以下序列编辑DSC电文:—— 格式符(selective/all ships/group/area))—— 输入海岸电台或另一船台的MMSI码;—— 选择类别(常规或船舶业务);—— 选择随后的通信方式(RT/ARQ/FEC));—— 如果是呼叫另一船台,应指明要求通信的频率或频道,如果是呼叫岸台,不应指明要求通信的频率或频道,而一般由岸台在其DSC确认中指明一个空闲的工作频道;3)在确认呼叫频率上没有其它的DSC呼叫后,船舶电台操作员可进行DSC呼叫。
题目——精选推荐
题⽬第⼀章1.简述GMDSS的基本含义。
GMDSS主要有哪些功能?2、GMDSS划分为哪⼏个分系统?各分系统船⽤的通信设备主要有哪些?3、GMDSS的海区是如何划分的?如何理解海区的概念?海区划分的⽬的是什么?4.在各海区航⾏的船舶⼀旦遇险应采⽤什么通信⼿段实现船⾄船、船⾄岸的遇险报警?5.根据船舶所航⾏的海区,应按怎样的标准配备GMDSS通信设备?6.按照SOLAS公约的要求,GMDSS船⽤设备维修保障⽅案有哪⼏种形式?对于航⾏在A1、A2海区以及A3、A4海区的船舶应怎样选择维修⽅案?7.GMDSS⽆线电通信⼈员的证书有⼏种?8.岸台或岸站在GMDSS中的作⽤主要有哪些?第⼗⼀章1、什么是海上移动业务识别码,⽔上识别数字,各种海上移动业务识别码有什么特点?3、船舶电台接收海岸电台DSC常规呼叫时,操作员应该如何操作?4、海岸电台,船舶电台,陆地⽤户的NBDP(窄带直接印字电报)应答码是如何构成的?5.NBDP常规呼叫前,操作员需要做什么准备?6、请简述船到岸,岸到船,船舶之间ARQ通信的⼿动呼叫和⾃动呼叫程序?7 、什么情况下,NBDP业务会采⽤FEC模式通信8、什么是电台呼号?船舶电台,海岸电台呼号是如何组成的?10、假设育龙号⼤幅,通过⼴州话台阶⼀个电话138********,呼叫⼯作流程?12、什么是通报表?通报表是如何发出的?13.MF/HF/VHF 收发设备的维护保养?14.DSC终端的检查与测试15.NBDP终端的维护保养第⼗⼆章1..Inmarsat-C系统的业务种类有哪些?2、简述Inmarsat-C系统电传/⽂本传真/低速数据/船⾄船通信业务的通信程序。
3、C系统,在不同存储转发报⽂业务情况下,⽬的地址如何设置?4、简述通过C系统的数据报告业务发送船位报告的⼀般程序。
5、简述通过C系统询呼业务调取船位信息,船舶应如何做好响应设置。
6、什么是Inmarsat-c系统的增值业务?7、通过北京地⾯站Cmail业务,实现船⾄岸Email传递,C船站的参数设置有何要求?8、如何通过北京地⾯站Cmail业务,实现C⼿机短信及传真业务?9、什么是IGW业务?10、Inmarsat-B/F系统的基本业务种类有哪些?11、简述Inmarsat-B系统,由船舶发起的电传通信基本程序,并分别给出船⾄岸、船⾄船通信时的拨号码组成。
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一、简述INMARSAT-B的船到岸自动电传通信程序。
参考答案:(1)选择合适的岸站,键入岸站识别码,呼叫岸站;
(2)收到GA+,键入完整的用户号码;
(3)收到用户应答码,调发电文;
(4)键入五个点,拆线。
二、简述INMARSAT-B开放的基本业务。
参考答案:遇险与安全通信,电话通信,电传通信,传真通信,数据通信
三、简述INMARSAT-B的船到岸自动电话通信程序。
参考答案:(1)拿起电话话筒;
(2)选择本船所在洋区的一个合适的岸站;
(4)拨岸站识别码,申请电话信道;
(5)听到拨号音后、立即拨出完整的用户号码;
(6)与被呼用户通话;
(7)主叫方挂机,拆除通信线路。
四、简述INMARSAT-C开放的基本业务。
参考答案:存储转发业务,遇险通信业务,EGC业务,数据报告与查询业务
五、简述INMARSAT-B船站遇险电话通信程序。
参考答案:1)设置遇险通信等级P=3;
2)拿起话筒,拨合适的岸站识别码;
3)通过岸站与RCC沟通,
4)向RCC发送遇险报告;
5)挂机拆线,回到职守状态
六、简述两种用INMARSAT-C进行遇险报警的方法。
参考答案:按下收发信机上的遇险报警按钮;通过发射窗口,选择遇险通信等级,发送遇险电文。
七、遇险报警一般应包括哪些内容?
参考答案:遇险船舶的识别,船位,遇险性质,遇险时间,要求援助的种类或任何有助于援助的其他信息。
八、简述两种进行DSC遇险呼叫的方法?
参考答案:单频呼叫尝试模式:在MF、HF或VHF频带中的某一个频率上,连续发送5次DSC遇险呼叫;多频呼叫尝试模式:在MF和HF频带中的多个遇险频率上轮流发送DSC 遇险呼叫。
九、简述VHF DSC发生误报警应采取的措施。
参考答案:(1)立即关掉收发信机
(2)打开收发信机,并把频率设定在VHF CH16
(3)向所有电台广播,提供船名、呼号和MMSI码,并解除误报警
十、简述MF DSC发生误报警应采取的措施。
参考答案:(1)立即关掉收发信机
(2)打开收发信机,并把频率设定在2182KHz
(3)向所有电台广播,提供船名、呼号和MMSI码,并解除误报警
十一、简述HF DSC发生误报警应采取的措施。
参考答案:(1)立即关掉收发信机
(2)打开收发信机,并把频率设定在与收到遇险报警频道对应的无线电话遇险通信频率上
(3)向所有电台广播,提供船名、呼号和MMSI码,并解除误报警
十二、国际上常用的报时信号有哪几种?
参考答案:老国际式,新国际式,英国式,美国式,国际韵律式,英国广播式
十三、NA VTEX报文格式中,技术编码B1B2B3B4分别表示何意?
参考答案:B1表示发射台的识别符,B2表示电文种类,B3 B4表示电文编号。
十四、NA VTEX报文的优先等级有哪几种?
参考答案:VITAL:极其重要电文,IMPORTANT:重要电文,ROUTINE:日常电文
十五、AMVER电报的种类有哪四种?
参考答案:航行计划报告SP,船位报告PR,抵港报告FR,改航报告DR
十六、航行于A1A2A3A4海区船舶,一般分别用什么方法接收MSI信息?
参考答案:A1A2海区:NA VTEX,A3:EGC,A4:HF NBDP。