Part Three: GPS, VDR, AIS, ECDIS

Passage one:

GPS, VDR

Learning Objectives:

• basic characteristics of GPS and VDR used on board

• working principles of GPS and VDR

• technical terms and phrases

• other relevant knowledge

Vocabulary:• ultimate /'ʌltimit/ adj. 最终的• dimensional /di'menʃənəl/ adj. …… 维的• differential adj. 差别的，微分的 e.g. DGPS ：差分 GPS• coordinate / kəu'ɔ:dineit/ n. ［ pl. ］座标（系 ) vt. integrate in a harmonious operation 协调，合

作• precisely /prI'saIslI/ adv. 精确地 • validity [və‘liditi/ n. 有效性 valid adj. 有效的• built-in adj. 内装的，嵌入的• retrievable /rI`tri:vəbl/ adj. 可恢复的 retrieval n.• acquisition /ækwi‘ziʃən/ n. something acquired 获得（物 / 人） radar acquisition 雷达探测 [ 截获 ]( 目标 )• capsule n. 容器，胶囊 • PDC (protective data capsule) 数据保护容器• sensor n. 传感器，敏感元件• digitally adv. 数字地 • subset n. 子集，子集合• erase vt. 擦除 erasure /i'reiʒə/ n. 擦除• module n. 组件• Server n. 服务器• anti-vibrator n. 抗震器• optionally adv. 非强制地，可任意选择地• catastrophic /kætə'strɔfɪk/ adj. 大灾难的，灾祸的 catastrophe /kə'tæstrəfi/ n.

last; finale.g. What was his ultimate goal? 他的最终目标是什么 ?

The Reference Station or land station is placed at a surveyed location, the coordinates of which are precisely known. 将参考站或地面控制站置于一个已确知坐标的测量点When two or more SAR units are working together, one person (OSC---On-scene Coordinator) is assigned to coordinate the activities of all participating units.两个以上搜救单位协同作战时，其中一方被指派协调所有参与单位的行动，即现场协调员the universal time coordinated (UTC) 协调世界时

e.g. He believed the information was retrievable. 他认为这些信息可以被恢复。

Europe has gone through two catastrophic world wars. 欧洲经历了两次世界大战的灾难。

GPS receiver is a precision navigation instrument

utilizing the latest technology available today to

provide optimum performance from the GPS sa

tellite and Beacon land signals received, as wit

h all other forms of radio signals. The ultimate n

avigation result is dependent upon the quality of

these signals. Radio signals may, on occasion,

be distorted, jammed, or otherwise incorrect. As

a result, your position accuracy may occasionall

y be less than that which can normally be expe

cted. The Global Positioning System, sometime

s referred to as NAVSTAR, is a satellite navigat

ion system developed by the US Department of

defense to provide both military and civilian use

rs with highly accurate, worldwise, all-weather, t

hree dimensional navigation and time. By recei

ving signals from orbiting GPS satellites, author

ized users are able to continuously navigate wit

h an accuracy on the order of 16 metres or bett

er.

distorted 失真； jammed 受屏蔽 / 干扰NAVSTAR GPS: Navigational Signal Timing and Ranging Global Positioning System （美国国防部开发的）卫星授 / 记时与测距导航系统（ 24 颗在 6 个轨道面上的卫星）

三维导航和时间数据

定位精度大约在 16 米以上。on the order of 大约e.g. I guess that she is on the order of 40. 我猜想她大约 40 岁。

GPS 接收器是一种精密的导航仪器。它利用当今最新技术根据收到的 GPS 卫星信号、陆地信标信号以及其他各种无线电信号提供最佳导航服务。as with ：与……一样， as with = as the case with

• In radar position-fixing, most accurate position fixes are obtained when the targets used are spaced nearly 90 degrees from each other. Similarly, GPS position fixing accuracy is subject to satellite location. Generally, the further apart the satellites are from one another, the greater the position-fixing accuracy.

• A technique referred to as Differential GPS (DGPS) allows users to obtain maximum accuracy from the GPS system. DGPS requires the use of two GPS receivers. One receiver, known as the Reference Station or land station, is placed at a surveyed location, the coordinates of which are precisely known. The purpose of the differential GPS system is to use the reference station to measure the errors in the GPS signals and to compute corrections to remove the errors. The corrections are then communicated in real-time to the navigators, where they are combined with the satellite signals received by the navigators, thereby improving their navigation or positioning. The geographic validity of these corrections is valid for navigators hundreds of kilometers from the reference station. DGPS stations are strategically located throughout America (including Hawaii and Alaska), Europe, Canada, Bermuda and Brazil.

Fig 1.  the  DGPS Broadcast Structure

一般说来，卫星之间的间距越大，定位的精确度就越高。The more…, the more 句式， further 是 far 的比较级。

The DGPS broadcast structure

这些更改数据 ( 改正量）随后实时地传送给导航仪，并与导航仪收到的卫星信号相结合，从而提高航行或定位（的准确性）。

将一个接收站，即参考站或地面控制站，置于一个已确知坐标的测量点

• Marine radio beacons operating in the 283.5 to 325.0 kHz frequency range are in widespread use for direction finding in coastal navigation. Because the beacon system has been in place and widely used for many years, it provides an effective means for the transmission of DGPS signals, depending on their local environment and power output. Their signals may be useable to several hundred miles. Marine beacons provide an economical means of obtaining DGPS accuracy for coastal navigators. GPS receivers with built-in beacon receivers are designed to provide low cost reception of DGPS corrections broadcast (normally free of charge) by coastal authorities.

• VDR

• A VDR records various data and events encountered aboard ship. The purpose of a voyage data recorder is to help investigators locate the causes of marine incidents. A VDR maintains a store in a secure and retrievable form of information concerning the movement, physical status, command and control of a vessel over the period leading up to and following an incident. This information is for use during any subsequent investigation to identify the cause(s) of the incident.

• The revised SOLAS Chapter V requires the installation of VDRs on passenger ships of 150 GT and above on all voyages and other ships of 3000 GT and above on international voyages and for newly built ships on and after 1 July, 2002.

• Data recorded by HLD-A (type) VDR is as follows:• Date and time Rudder order and response• Heading (true, magnetic) Engine order and response• Position Watertight and fire door status• Speed (water and/or ground) Wind speed and direction• Depth under keel Radar image• Main alarms Bridge audio • VHF communications audio

航程数据记录仪将信息以安全且可恢复的模式储存，这些信息涉及了导致事故发生以及事故发生后一段时间内的船舶动态、自身状况、船舶操纵及控制等方面。in a secure and retrievable form 介词短语作方式状语，插在了 a store of information 当中。leading up to (an incident) and following an incident ：分词短语做定语修饰前文中船舶动态、船舶操纵等内容，相当于一个定语从句 which lead up to and follow an incident 。

• The HLD-A VDR system has been developed to fulfill and exceed the above mission requirement. The following components form the basis of the voyage data recorder system.

• Main Electronics Enclosure (VDR server box) Remote Acquisition Unit• Remote Alarm Box Protective Data Capsule

(PDC)• Connecting Junction Box Power unit• Microphone / speaker box (interior and exterior)

• The VDR system continuously records bridge audio communications sensor data, alarm status as well as radar screen images. The recorded data is digitally stored on the server’s computer hard disk. A subset or copy of the data is also stored on the final recorder media, which is housed in a Protective Data Capsule (PDC). The capsule ensures survival and recovery of the recorded data after an incident. The VDR system continuously stores data from the past 12 hours in the capsule, erasing the oldest data stored as new data is recorded.

• The VDR system is designed to operate automatically once it is set up correctly. There is no user interaction. The VDR server software modules run on the WIN 2000 operating system. The design incorporates both hardware and software features which prevent the shutdown of the system, alteration, erasure or accidental loss of data.

航程数据记录仪系统将过去 12小时的数据连续不断地储存在数据保护容器中，并随着新数据的输入，抹去储存的最老的数据。as引导时间状语从句，表示随着……。

• All system faults are reported by the Bridge Alarm Unit (BAU). An error log is saved on the VDR server. Authorized service engineers can access this log to service and if necessary repair the VDR. The server, which sits on anti-vibrator, contains the main processing unit, which is a high-performance and industrial grade computer with built-in audio recording and network capabilities. The computer may be optionally fitted with a DVD writer. The computer will automatically copy the last 12 hours of recorded data onto a DVD disk whenever a disc is inserted into the DVD writer. This functionality allows last 12 hours of recorded data to be removed from the VDR for any “non-catastrophic” incidents, which require retrieval of the protected data capsule.

这项功能允许移除航程数据记录仪中最近 12小时所记录的任何“非灾难性”事故的数据。而这需要恢复数据保护容器。allow…to… ：允许……做某事

这种安装在抗震装置上的服务器内含主处理器。这种主处理器是一种带有嵌入式录音及网络功能的高性能、工业用计算机。该句的主语 the server 和宾语 the main processing unit 各自带有一个非限定性定语从句。

Language Points to remember:

• DGPS：• PDC (protective data capsule)• anti-vibrator n. • NAVSTAR• Reference Station• voyage data recorder• Bridge Alarm Unit (BAU)•“non-catastrophic” incidents

差分 GPS

数据保护容器

抗震器

卫星授 / 记时与测距导航系统

参考站

航程数据记录仪（黑匣子）

驾驶台报警装置

非灾难性事故

Preview ：

• Passage Two

• AIS and ECDIS