Unit 18

I. Выпишите из Прил. 1 значения следущих слов, запомните их:

part (n), determine (v), velocity (n), remote (a), observer (n), penetrate (v), employ (v), obtain (v), estimation (n).

П. Выпишите из Прил. 2 значения следущих терминов, запомните их:

sonar

echo location

round-trip time

III. Сгруппируйте синонимы, переведитеих:

1. Determine (v), velocity (n), remote (а), observe (v), employ (v), obtain (v), show (v), part (n), device (n), powerful (a), refer to (v).

2. Distant (a), watch (v), demonstrate (v), get (v), strong (a), call (v), fraction (n), unit (n), speed (n), define (v) use (v).

IV. Прочтите текст, скажите, для каких целей используются системы радиолокации и гидролокации.

RADAR AND SONAR

1. Radar and sonar are used to determine the range, velocity and direction of objects that are remote from the observer. Radar employs electromagnetic radiation, usually at microwave frequencies, and is generally used to observe airborne (воздушный) objects and objects in outer space. Sonar uses sound waves and can therefore be used under water where the electromagnetic waves of radar do not penetrate.

2. Radar and sonar systems can be active or passive. An active system employs a powerful transmitter that sends signals towards the target and analyses the resulting echo. A passive system uses only a receiver and obtains target information from signals radiated by the target itself. Most radars are active, while many sonars are passive. In active system range is determined in terms of round-trip time between the emission of a signal and the reception of the echo. The process is referred to as echo location. Since passive systems emit no signals, they cannot employ echo location. They are therefore limited to detection (i. e., to decide whether a certain kind of target is present or not) and estimation of direction.

(1.300)

V. Задания к тексту.

Найдите в тексте интернациональные слова и переведите их, не обращаясь к словарю. Выпишите из текста многокомпонентные определительные словосочетания и переведите их.

Прочтите 1 абзац текста, перечислите его основные положения.

Прочтите 2 абзац текста, ответьте на вопрос:

What is the difference between active and passive systems?

Переведите текст абзаца.

VI. Дайте русский эквивалент представленных в скобках слов в соответствующей форме. Переведите текст.

Radar (обнаруживать) targets and (определять) their distance and direction. The operation of radar (основываться) the principle of wave reflection. Radar (состоять) essentially of a timer, pulser (modulator), magnetron transmitter, transmit-receiver switch, scanning antenna, superheterodyne receiver and cathode-ray tube indicator. The timer (обеспечивать) synchronism between the transmitted pulse and the indicator time base. The pulser (включать) the transmitter in order to send out a radar pulse over the antenna. The superhet receiver (обнаруживать) and (усиливать) the reflected echo pulse from the target, which is displayed on the screen of the indicator.

Radar (использовать) electromagnetic radiation, sonar (применять) sound waves.