电子与通信技术专业英语UnitⅣ-18课件.ppt

1、Unit Communication TechnologyLesson 18 Satellite CommunicationNew Words block blk n. 街区 global lubl a. 球形的, 全球的, 全世界的 culmination ,klminein n. 顶点 era ir, r n. 时代, 纪元, 时期 span spn v. & n. 横越; 跨度, 跨距, 范围 cumbersome kmbsm a. 讨厌的, 麻烦的, 笨重的 syncom sikm n. (美国的) 同步通信卫星 geostationary di:usteinri n. 与地球的相对

2、位置不变的 altitude ltitju:d n. (尤指海拔)高度 equator ikweit n. 赤道 enormous in:ms a. 巨大的 equidistant ,i:kwidistnt a. 距离相等的, 等距的Phrases and Expressions tennis match n. 网球比赛 prior to ad. 在前, 居先 globe-spanning communications network 全球通信网络 Notes1. An international telephone call is made as easily as a local call

3、 to a friend who lives down the block. as easily as：“像一样(容易)”，easily修饰动词made，充当状语。请比较：Our classroom is as big and bright as theirs (形容词big and bright充当表语)。2. This capability to exchange information on a global basis, be it a telephone call or a news story, is made possible through a powerful communi

4、cations tool - the satellite. 这种进行全球性信息交流的能力，无论是电话还是新闻转播都是通过一个强有力的通信工具卫星，才得以实现的。 句中be it a telephone call or a news story：这是一个倒装句，完整的句子应是, whatever it is a telephone call or a news story 3. that stretches back to an era when the term satellite was only an idea conceived by a few inspired individuals

5、. (1) that引导定语从句，修饰dream；(2) to stretch back：“回顾、追溯”，相当于to recall back；(3) an era：这里应指全球卫星通讯系统仍在人们头脑中灵感的想象年代，其后有when引导的定语从句修饰。4. These pioneers included authors such as Arthur C. Clarke, who fostered the idea of a worldwide satellite system in l945. 句中who引导非限制性定语从句，修饰Arthur C. Clarke。5. The latter t

6、ype of satellite system would have entailed the development of a very complex and cumbersome earth and space-based network. 句中latter：adj.后面的, (两者中)后者的, 近来的，指顺序的先后；而later指时间的先后。6. Rather than circling the earth at a rapid rate of speed, the spacecraft appeared to be stationary or fixed in the sky. (1

7、) rather than：“而不是”，置于句首可起强调作用； (2) 句型to appear to do sth.：“似乎 / 碰巧做某事”，后文中仍有此用法。7. Simply stated a satellite in a geostationary orbital position appears to be fixed over one portion of the earth. 句中simply stated：“简单地说”，相当于simply speaking，请比较: generally speaking (总地来说)。8. Prior to this era, a ground

8、 stations antenna had to physically track a satellite as it moved across the sky. 在这以前，地面站的天线必须机械地转动以跟随在天空中运动的卫星。 (1) prior to this era：“在此之前、在这个年代之前”，相当于before this age；(2) as引导时间状语从句。 Translation of TextsLesson 18 Satellite Communication Satellite communication has become a part of everyday life i

9、n the late 1980s. An international telephone call is made as easily as a local call to a friend who lives down the block. We also see international events, such as an election in England and a tennis match in France, with the same regularity as local political and sporting events. In this case, a te

10、levision news program brings the sights and sounds of the world into our homes each night.第第18课课 卫星通信卫星通信 20世纪80年代后期，卫星通信逐渐成为日常生活的一部分，打一个国际电话就像给住在同一街区的朋友打本地电话一样简单。同样，我们获悉国际大事，像英国的竞选、法国的网球赛就像得知本地政治、体育新闻一样平常。此时电视新闻节目每天晚上都将全世界的声音和画面带进我们的家中。 This capability to exchange information on a global basis, be

11、it a telephone call or a news story, is made possible through a powerful communications tool-the satellite. For those of us who grew up at a time when the space age was not a part of everyday life, satellite-based communication is the culmination of a dream that stretches back to an era when the ter

12、m satellite was only an idea conceived by a few inspired individuals. These pioneers included authors such as Arthur C. Clarke, who fostered the idea of a worldwide satellite system in l945. This idea has subsequently blossomed into a sophisticated satellite network that spans the globe. 这种进行全球性信息交流

13、的能力，无论是电话还是新闻转播都是通过一个强有力的通信工具卫星，才得以实现的。对于我们中那些并非生长在太空时代的人们来讲，卫星通信是人们长期以来一种梦想的顶点，这个梦想可以一直追溯到卫星这个词只是几个天才头脑中灵感的想象那个年代。这些先驱者中就包括亚瑟.克拉克，他在1945年就产生了全球卫星系统的想法，这个想法随后发展成为一个遍布全球的复杂卫星网络。 The latter type of satellite system would have entailed the development of a very complex and cumbersome earth and space-ba

14、sed network. Fortunately though, this problem was eliminated in 1963 and 1964 through the launching of the Syncom satellite. Rather than circling the earth at a rapid rate of speed, the spacecraft appeared to be stationary or fixed in the sky. Today communications satellites, for the most part, have

15、 followed suit and are now placed in what are called geostationary orbital positions or “slots”. 亚瑟克拉克设想的卫星通信系统将导致开发一个相当复杂和麻烦的基于地面的空间站的网络。幸运的是，这个问题随着1963年和1964年同步卫星的发射成功而消失。现在的卫星不是高速地围绕地球运行，而是静止或固定在空中，目前大部分通信卫星都被定位在相对地球静止的轨道或称之为“槽”的位置上。 Simply stated a satellite in a geostationary orbital position a

16、ppears to be fixed over one portion of the earth. At an altitude of 22,300 miles above the equator, a satellite travels at the same speed at which the rotates, and its motion is synchronized with the earths rotation. Even though the satellite is moving at an enormous rate of speed, it is stationary

17、in the sky in relation to an observer on the earth. 简单地讲，在一个对地面相对静止的轨道位置上的卫星对地球的一部分地区表现为固定的，在赤道上空22300公里的高度上，卫星与地球以同样的角速度运行，即它的运转与地球的自转是同步的。尽管卫星是以很高的速度运行，对于一个地球上的观察者而言，它总是停留在天空中的同一个位置上。 The primary value of a satellite in a geostationary orbit is its ability to communicate with ground stations in it

18、s coverage area 24 hours a day. This orbital slot also simplifies the establishment of the communications link between a station and the satellite. Once the stations antenna is properly aligned, only minor adjustments may have to be made in the antennas position over a period of time. The antenna is

19、 repositioned to a significant degree only when the station establishes contact with a satellite in a different slot. Prior to this era, a ground stations antenna had to physically track a satellite as it moved across the sky. 位于一个对地面相对静止的轨道上的卫星的主要作用在于它可一天24小时地与它覆盖的地面保持联系。这个轨道的位置同时使建立卫星与地面站之间的通信链路更加

20、简单化（如图181所示）。当一个站的天线处在适当的位置，在一段很长时间内天线的位置只需作微小的调整。只有当一个站要与另外一个卫星建立联系时，天线的位置才需作显著的调整。在这以前，地面站的天线必须机械地转动以跟随在天空中运动的卫星。 Based on these principles, three satellites placed in equidistant positions around the earth can create a world-wide communications system in that almost every point on the earth can b

21、e reached by satellite（as shown in Fig.181）. This concept was the basis of Arthur Clarkes original vision of a globe-spanning communications network. 基于这些原理，围绕地球等距离位置上放置三颗卫星就可建立一个全球的通信系统，以使地球上的每一个点都能与卫星相联。这个概念也是以亚瑟.克拉克的最早有关全球通信网络蓝图为基础的。 Exercises1. Write T (True) or F (False) beside the following st

22、atements about the text.a. Satellite communication has become a part of everyday life in the late 1960s.b. An international telephone call is still not easy as a local call.c. We can see international events in our homes each night by the television news program. d. Satellite communication brings th

23、e sights and sounds of the world via a television set.e. Now satellite-based communication only is a dream by a few inspired individuals.f. In l945, Arthur C. Clarke had deverloped a worldwide satellite system.g. Todays communications satellites, for the most part, circling the earth at a rapid rate

24、 of speed.h. The satellite is stationary in the sky in relation to an observer on the earth.2. Match the following terms to appropriate definition or expression.a. satellite 1. create a world-wide communications b. “slots” 2. geostationary orbital positions c. three satellites 3. a powerful communic

25、ations tool 3. Fill in the missing words according to the text.a. Fortunately though, _ problem was eliminated in 1963 and 1964 through the launching of the Syncom satellite.b. Based on _ principles, three satellites placed in equidistant positions around the earth can create a _ system in that almo

26、st every point on the earth can be reached by satellite.c. This orbital slot also simplifies the establishment of the communications link between _ and_.d. Prior to this era, a ground stations _ had to physically track a satellite as it moved across the _.4. Translate the third paragraph into Chinese. End