Chapter 11 Marine

Communication

Passage Two

Composition of GMDSS

EPIRB (Emergency

Position Indicating Radio

Beacon)An EPIRB (Emergency Position Indicating

Radio Beacon) is a device which, in the event of an emergency, transmits a signal

that alerts search and rescue (SAR) authorities and enables rescue units to home in on the scene of the accident

应急无线电示位标 (EPIRB)

EPIRB The device transmits a continuous signal which provides the ship’s identity and pos

ition to within four miles. The signal can be activated manually but the EPIRB must also be able to float free and begin signaling automatically in the event of a sudden accident(such as the ship capsizing before any other form of signal can be given).

EPIRBs are designed to alert a shore Rescue Co-ordination Centre(RCC), via a satellite link, in the event of an emergency. They can be operated both manually and automatically. They will also provide the identity and approximate position of the ship in distress. The RCC will then use modern communications to discover what ships are in the vicinity and marshal appropriate resources to provide assistance.

For this purpose the GMDSS establishes the communication systems which will be by ships subject to SOLAS for Distress and Safety communications. These include VHF, MF, HF and satellite services.

In addition, the GMDSS establishes broadcast systems for the transmission and automatic receipt of Maritime Safety Information(MSI). This includes Navigational Warnings, Meteorological Warnings, Meteorological Forecasts, Initial Distress Alerts and other urgent information. The two systems to be used for this are Navtex and the INMARSAT Safety Net service.

Cospas-Sarsat Cospas-Sarsat is an international satellite-based search and rescue

system, established by Canada, France, the United States, and Russia. These four countries jointly helped develop the 406 MHz Emergency Position-Indicating Radio Beacon (EPIRB), an element of the GMDSS designed to operate with Cospas-Sarsat system. These automatic-activating EPIRBs, now required on SOLAS ships, commercial fishing vessels, and all passenger ships, are designed to transmit to alert rescue coordination centers via the satellite system from anywhere in the world. Newest designs incorporate GPS receivers to transmit highly accurate positions of distress. By the end of 2010 EPIRB manufacturers may be offering AIS (Automatic Identification System) enabled beacons The service on these items are check once annually and have limited battery life due to compositions in the elements discharge EPIRB's hold all ships data such as MMSI( Maritime Mobile Service Identity), call sign, gross tonnage etc...

The International Convention for the Safety of Life at Sea (SOLAS) is an international maritime safety treaty. The SOLAS Convention in its

successive forms is generally regarded as the most

important of all international treaties concerning the safety

of merchant ships.

NAVTEX Navtex is an international, automated system for instantly distributing

maritime navigational warnings, weather forecasts and warnings, search and rescue notices and similar information to ships. A small, low-cost and self-contained "smart" printing radio receiver installed on the bridge, or the place from where the ship is navigated, and checks each incoming message to see if it has been received during an earlier transmission, or if it is of a category of no interest to the ship's master. The frequency of transmission of these messages is 518 kHz in English, while 490 kHz is used to broadcast in local language.

The messages are coded with a header code identified by the using alphabets to represent broadcasting stations, type of messages, and followed by two figures indicating the serial number of the message.

INMARSAT Satellite systems operated by the INMARSAT, overseen by IMSO,

International Mobile Satellite Organization are also important elements of the GMDSS. The types of INMARSAT ship earth station terminals recognized by the GMDSS are: INMARSAT B, C and F77. INMARSAT B and F77, an updated version of the now redundant INMARSAT A, provide ship/shore, ship/ship and shore/ship telephone, telex and high-speed data services, including a distress priority telephone and telex service to and from rescue coordination centers. The F77 is meant to be used with the INMARSAT C, since its data capability does not meet GMDSS requirements. (CHECK INMARSAT SITE, this says otherwise). The INMARSAT C provides ship/shore, shore/ship and ship/ship store-and-forward data and email messaging, the capability for sending preformatted distress messages to a rescue coordination center, and the INMARSAT C Safety NET service. The INMARSAT C Safety NET service is a satellite-based worldwide maritime safety information broadcast service of high seas weather warnings, NAVAREA navigational warnings, radio navigation warnings, ice reports and warnings generated by the USCG-conducted International Ice Patrol, and other similar information not provided by NAVTEX. Safety NET works similarly to NAVTEX in areas outside NAVTEX coverage. INMARSAT C equipment is relatively small and lightweight, and costs much less than an INMARSAT B or F77. INMARSAT B and F77 ship earth stations require relatively large gyro-stabilized antennas; the antenna size of the INMARSAT C is much smaller.

被全球海上遇险与安全系统认可的国际海事卫星船舶地面终端类型是 : 国际海事卫星的 B 站 ,C 站和F77 站。 (77 代表天线是77 厘米 )

High Frequency Under a cooperative agreement with the

National Oceanic and Atmospheric Administration (NOAA), combined meteorological observations and AMVER reports can now be sent to both the USCG AMVER Center, and NOAA, using an INMARSAT C ship earth station, at no charge. SOLAS now requires that INMARSAT C equipment have an integral satellite navigation receiver, or be externally connected to a satellite navigation receiver. That connection will ensure accurate location information to be sent to a rescue coordination center if a distress alert is ever transmitted.

High Frequency A GMDSS system may include High Frequency (HF) radiotelephone

and radiotelex (narrow-band direct printing) equipment, with calls initiated by digital selective calling (DSC). Worldwide broadcasts of maritime safety information are also made on HF narrow-band direct printing channels.

Search and Rescue Transponder

The GMDSS installation on ships include one or more Search and Rescue Transponder (SART) devices which are used to locate survival craft or distressed vessels by creating a series of dots on a rescuing ship's 3 cm radar display. The detection range between these devices and ships, dependent upon the height of the ship's radar mast and the height of the SART, is normally about 15 km (8 nautical miles). Note that a marine radar may not detect a SART even within this distance, if the radar settings are not optimized for SART detection. Once detected by radar, the SART will produce a visual and aural indication.

这些装置 (SART) 与船舶之间的探测距离通常有 15 千米 (8 海里 ), 并且探测距离取决于船舶雷达的天线高度以及搜救雷达应答器 (SART)

放置的高度。 值得注意的是 : 如果一台雷达没有调节到探测搜救雷达应答器的最佳状态 , 即使在雷达探测范围内 , 也有可能探测不到它。

Digital Selective Calling The IMO also introduced Digital Selective Calling (DSC) on MF, HF and

VHF maritime radios as part of the GMDSS system. DSC is primarily intended to initiate ship-to-ship, ship-to-shore and shore-to-ship radiotelephone and MF/HF radio telex calls. DSC calls can also be made to individual stations, groups of stations, or "all stations" in one's reach. Each DSC-equipped ship, shore station and group is assigned a unique 9-digit Maritime Mobile Service Identity.

DSC distress alerts, which consist of a preformatted distress message, are used to initiate emergency communications with ships and rescue coordination centers. DSC was intended to eliminate the need for persons on a ship's bridge or on shore to continuously guard radio receivers on voice radio channels, including VHF channel 16 (156.8 MHz) and 2182 kHz now used for distress, safety and calling. A listening watch aboard GMDSS-equipped ships on 2182 kHz ended on February 1, 1999. In May 2002, IMO decided to postpone cessation of a VHF listening watch aboard ships. That watchkeeping requirement had been scheduled to end on 1 February 2005.

IMO and ITU both require that the DSC-equipped MF/HF and VHF radios be externally connected to a satellite navigation receiver. That connection will ensure accurate location information is sent to a rescue coordination center if a distress alert is ever transmitted. The FCC requires that all new VHF and MF/HF maritime radiotelephones type accepted after June 1999 have at least a basic DSC capability.

VHF digital selective calling also has other capabilities 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 Ship borne Automatic Identification System, which will be DSC-compatible. Countries having a GMDSS A1 Area should be able to identify and track AIS-equipped vessels in its waters without any additional radio equipment. A DSC-equipped radio cannot be interrogated and tracked unless that option was included by the manufacturer, and unless the user configures it to allow tracking.

Vocabulary authority [] n. 权威机关 capsize [] v. 倾覆 continuous [] adj. 连续的 identity [] v. 识别 manually [] adv. 手动地 automatically [] adv. 自动地 marshal [] v. 安排 appropriate [] adj. 恰当的，合适的 accurate [] adj. 精确的，准确的 narrow-band direct printing 窄带打印 integral [] adj. 完全的；缺一不可的，主要的 optimize [] v. 使最优化，使最佳化。 individual [] adj. 单一的，个别的，单独的。 compatible [] adj. 协调的，相容的 , 不矛盾的 capability [] n. 能力 interrogate [] v. 询问，质问，提出问题 manufacturer [] n. 制造商 configure [] v. 使成形

1.The Definition of EPIRB

EPIRB ： Satellite-Emergency Position Indicating Radio Beacon 简称 EPIRBs 。

无线电示位标：是一种能够发射无线电信号的装置 ,利用自身发射的无线电信号，表明其所处位置。

EPIRB ：无线电信号是靠卫星中继，在紧急情况下，可自动或人工启动示位标发出报警信号，经过卫星转发到地面接收站，最后送到救助协调中心（ RCC ），由 RCC 组织搜救工作。

2.The Function of EPIRB

报警 (alarm): 载体遇到危险时能够自动 (AUTO) 或人工 (MANUAL)发射遇险报警。

识别 (identification): 发射的报警信号中含有识别信息 , 便于确定载体。

定位 (position): 信号中含位置信息 (GPS), 或通过测试其发射的信号 ,得出其位置 ( 利用多谱勒效应 ) 。

寻位 (homing): 发射无线电测向信号 , 便于飞行器寻找。（ 121.5MHz ）

3.The Classification of EPIRB

（ 1 ） COSPAS-SARSAT 系统 S-EPIRB （ 406M ） ;

（ 2 ） INMARSAT 系统 L-EPIRB （ 1.6M ）；（ 2006 年 12 月 1 日关闭 L-EPIRB 系统，国际移动通

信卫星组织不再提供此项业务 ） （ 3 ）地面通信系统中 VHF-EPIRB （ CH70 ） ; 已

经停产，用 70 频道发送遇险报警信息，通过 VHF 系统传输到有关部门。

COSPAS-SARSAT

1 、 The Background Of COSPAS-SARSAT 2 、 Components Of COSPAS-SARSAT 3 、 The Working Theory Of COSPAS-

SARSAT

1 、 The Background Of COSPAS-SARSAT

SARSAT stands for Search And Rescue Satellite-Aided Tracking. Cospas-Sarsat is an element of the Global Maritime Distress Safety System (GMDSS). Automatic-activating EPIRBs are now required on International Convention for the Safety of Life at Sea (SOLAS) ships, commercial fishing vessels, and all passenger ships, are designed to transmit to a Rescue Coordination Centre a vessel identification and an accurate location of the vessel from anywhere in the world.

Cospas-Sarsat is an international satellite-based search and rescue (SAR) distress alert detection and information distribution system, established by Canada, France, the United States, and the former Soviet Union in 1979.The system consists of both a ground segment and a space segment:COSPAS-SARSAT 系统 :

（ COSPAS 是俄文的拉丁化，英文的全称是 Space System For Search of Distress Vessels , SARSAT- Search And Rescue Satellite Aided Tracking ），

利用空间卫星为世界各地搜救部门免费提供海事、民航和陆地遇险者报警和定位信息的系统，原称为“低极轨道搜救卫星系统”，近年来，该系统中又引入了静止卫星作为转发器，因此现在系统更名为－－“国际搜救卫星系统” 。

Information Of COSPAS-SARSAT

Since the inception of Cospas-Sarsat in 1982, distress radiobeacons have assisted in the rescue of over 22,000 people in more than 6,000 distress situations. In 2006, distress radiobeacons aided in the rescue of 1,881 people in 452 distress situations.

自 1982 年使用以来，共救助 22 ， 000 人接警6000余次。仅 2006 年，救助 1881 人接警 452次。

Orbital velocity: 7 km per second→ about 100 minutes per orbit

“Swath” about 4,000 km wideSatellite crosses visible sky

in about 15 minutes

Low Earth Orbit COSPAS-SARSAT

satellites

Low Earth Orbit COSPAS-SARSAT

satellites

Satellitefield of view

Satellitefield of view

GEO satellites orbit theearth once each 24 hours

and appear stationary over a point on the earth’s surface

EU MSG

MSG GEO

Future:EU Galileo GPSDASS MEO Satellites

Local User Terminal has greater than 1500 NM radius

Local User Terminal has greater than 1500 NM radius

北京 LUT 覆盖区域图

Rescue Co-ordination Centre (RCC)

EPIRBs are designed to alert a shore Rescue Co-ordination Centre (RCC), via a satellite link, in the event of an emergency. They can be operated both manually and automatically. They will also provide the identity and approximate position of the ship in distress.

The RCC will then use modern communications to discover what ships are in the vicinity and marshal appropriate resources to provide assistance.

Thank You!