3. Read the following text: radar

The word «Radar» means Radio Detection and Ranging. Radar equipment is capable of determining by radio echoes the presence of objects, their direction and range.

There are several types of radar sets, all of their consisting of 6 essential components: a transmitter, a receiver, an antenna system, an indicator, a timer, and a power supply.

A radar set detects objects by sending out short powerful pulses of ultra-high frequency radio wave energy from a high-power transmitter. The directional antenna takes this energy from the transmitter and radiates it in a beam. As the transmitted energy strikes the object, a portion of it is reflected back. The receiver picks up the returning echo through its antenna and translates it into visual readable signals on a fluorescent screen. The appearance of these signals shows the presence of an object within the field of view of radar.

The electron beam sweeps across the fluorescent screen and may be made to travel across any portion of the screen in some predetermined interval of time. The timer, which is the synchronizer of the whole system, times the transmitter pulse and the indicator. The use of these timed pulses and the fact that the radio waves travel at the constant velocity of light gives a simple means of measuring range.

How is then the direction in which on object lies to be found. Both azimuth and elevation can be determined by means of the directional antenna. The antenna may be rotated as the pulses are sent out and the strongest signal appears on the screen when the antenna points directly at the object. The direction of the antenna enables the determination of azimuth and elevation. Thus, with the help of a radar set we can get a three-dimensional location of an object.

The wide use of radar sets in our everyday life makes air and sea entirely safe. Radars may be installed on every ship at sea as well as in every harbour. They will prevent collisions in fog and help a ship to sail safely into any harbour regardless of night or weather.

Notes:

* Слово “antenna” имеет две формы множественного числа -

antennae - образованная по законам латинского языка, и

antennas - образованная по законам английского языка.

**a timer - синхронизирующее устройство; таймер

to time - устанавливать, отмечать время

1. Words to be learnt:

detection — обнаружение range - расстояние

radar set — радиолокационная станция /РЛС/

transmitter — передатчик

receiver — приемник

indicator — индикатор

power supply — блок питания

velocity — скорость

to send out — посылать

to travel — перемещаться

to install — устанавливать, сооружать

to prevent — предотвращать

EXERCISES

1. What's the Russian for:

range, collision, radar set, to reflect, to travel, to send out pulses, to install, screen, transmitter, to prevent.

2.Translate into Russian:

1) As the transmitted energy strikes the object, a portion of it is reflected back.

2. The timer, which is the synchronizer of the whole system, times the

transmitter pulse and the indicator.

2. The use of these timed pulses and the fact that the radio waves travel at the constant velocity of light gives a simple means of measuring range.

3. The antenna may be rotated as the pulses are sent out and the strongest signal appears on the screen when the antenna points directly at the object.

5) Translate the following word combinations:

radio detection and ranging, radar equipment, radar set, antenna system, power supply, radio wave energy, ultra-high frequency, ultra-high frequency radio wave energy, high-power transmitter, three-dimensional location of an object.