EXERCISE 2 Study the vocabulary

Global Positioning System (GPS) - глобальная (спутниковая) система местоопределения

Global Orbiting Navigation Satellite System (GLONASS) - глобальная (спутниковая) орбитальная система навигации

accurate – точный

triangulation – триангуляция

handheld - ручной; передвижной, переносной, портативный

pinpoint – указать точно

EXERCISE 3

Discuss the advantages of Global Positioning and Navigation Systems.
UNIT VII

РАЗДЕЛ VII

FEEDERS

ФИДЕРЫ
Text I

Antenna-feeder devices
EXERCISE 1

Read and translate the text using the following words and word combinations:

Antenna-feeder devices provide receiving and transmitting electromagnetic signals. Such devices consist of antenna, which radiates and receives radio waves, and feeder. Feeder is a cable or a waveguide which conducts oscillations from generator to the transmitting antenna and from receiving antenna to the receiver. Shape, size and configuration of the device could be different and depend on the length of a radiated and received wave.

Physical characteristics of antenna are the following:

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  Wind load and vibration. In fact, antennas are usually placed on the roofs of buildings where wind load is maximum. So antenna’s construction and its bolting must withstand wind speed 160 km/h. Besides, antennas must be designed to undergo vibration up to 5 g (where g = 9,81 m/sec² ).
  
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  The environmental temperature should be within – 40 ºC to + 50 ºC, so that antenna could operate continuously.
  
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  Humidity and acing (frost) shouldn’t prevail 95%, otherwise antenna’s efficiency will get worse. But afterwards, when these factors stop effecting the antenna, its properties must be possible to restore.