NAVEDTRA 14190A NEETS Mod. 18, Ch. 1

Question 1

Which term is used to refer to electronic equipment that detect the presence, direction, height, and distance of objects by using reflected electromagnetic energy?

Answer 1

Radar

Question 2

What is used by radar sets to determine the direction and distance of the reflecting object?

Answer 2

Echo

Question 3

The surface of the earth is represented by an imaginary flat plane, tangent (or parallel) to the earth’s surface at that location. What is this plane referred to as?

Answer 3

Horizontal plane

Question 4

What is the line from the radar set directly to the object referred to as?

Answer 4

Line of Sight (LoS)

Question 5

What is the angle called between the horizontal plane and the los?

Answer 5

Elevation angle

Question 6

Approximately how many statute miles per second does electromagnetic energy travel through the air? 


Answer 6

186,000

Question 7

Approximately how many nautical miles are equal to 186,000 statute miles?

Answer 7

162,000

Question 8

Approximately how many feet are there per nautical mile?

Answer 8

6,080

Question 9

What is radar timing usually expressed in?

Answer 9

Microseconds

Question 10

Approximately how many feet per microsecond does radiated energy from a radar set travel at?

Answer 10

984

Question 11

The range in nautical miles to an object can be found by measuring the elapsed time during a round trip of a radar pulse and dividing this quantity by what number?

Answer 11

12.36

Question 12

Which pulse property determines the maximum range that the pulse can travel to a target and still return a usable echo?

Answer 12

Peak power

Question 13

What is the smallest signal called that is detectable by a receiver system that can be processed and presented on an indicator?

Answer 13

Usable echo

Question 14

What is the frequency of the rf energy in the pulse radiated by a radar referred to as?

Answer 14

Carrier frequency

Question 15

Radio frequency energy above what frequency is rapidly attenuated by the atmosphere?

Answer 15

3,000 megahertz

Question 16

What is used to calculate both the peak power and average power of a radar system?

Answer 16

Duty cycle

Question 17

Which radar target property is the angle between true north and a line pointed directly at the target?

Answer 17

True bearing

Question 18

Which radar systems are designed to determine only the range and bearing of an object?

Answer 18

2D

Question 19

Which type of search radar system detects altitude as well as range and bearing?

Answer 19

3D

Question 20

Which radar property is defined as its ability to distinguish between targets that are very close together in either range or bearing? 


Answer 20

Target resolution

Question 21

Which two categories is resolution usually divided into?

Answer 21

Range and Bearing

Question 22

What is the ability referred to as of a radar system to distinguish between two or more targets on the same bearing but at different ranges? 


Answer 22

Range resolution

Question 23

What is the ability of a radar system to separate objects at the same range but at different bearings?

Answer 23

Azimuth resolution

Question 24

What is a measure of the ability of a radar system to determine the correct range, bearing, and, in some cases, height of an object?

Answer 24

Radar accuracy

Question 25

What is the bending of electromagnetic waves caused by a change in the density of the medium through which the waves are passing?

Answer 25

Refraction

Question 26

What ensures that all circuits connected with the radar system operate in a definite timed relationship?

Answer 26

Synchronizer

Question 27

What is essentially an electronic switch that permits a radar system to use a single antenna to both transmit and receive? 



Answer 27

Duplexer

Question 28

What is the systematic movement of a radar beam in a definite pattern while searching for or tracking a target?

Answer 28

Scanning

Question 29

Which type of scanning is unsuitable for use as a tracking radar?

Answer 29

Single-lobe

Question 30

What are the two basic methods of beam scanning?

Answer 30

Mechanical and Electronic

Question 31

Which type of scanning is used in fire-control tracking radars?

Answer 31

Monopulse

Question 32

What can occur as the target maneuvers or moves and the radar pulses bounce off different areas of the target and causes random reflectivity and may lead to tracking errors?

Answer 32

Scintillation

Question 33

When radio-frequency energy transmitted from a fixed point continuously strikes an object that is either moving toward or away from the source of the energy, the frequency of the reflected energy is changed. What is this shift in frequency known as?

Answer 33

Doppler effect

Question 34

What is a requirement for any doppler radar to function?

Answer 34

Coherence

Question 35

What is the heart of a missile guidance system?

Answer 35

Radar system

Question 36

Which type of radar is designed to continuously scan a volume of space to provide initial detection of all targets?

Answer 36

Search

Question 37

Which type of radar provides continuous range, bearing, and elevation data on one or more targets?

Answer 37

Track

Question 38

Which type of radar systems detect and process only moving targets?

Answer 38

Moving Target Indicators

Question 39

What is the maximum range ability of surface-search radar primarily limited by radar horizon?

Answer 39

Radar horizon

Question 40

Which type of radar is used to detect the presence of surface craft and low flying aircraft and to determine their presence?

Answer 40

Surface-search

Question 41

The maximum range of air-search radar can exceed how many miles?

Answer 41

300

Question 42

Which type of radar computes accurate ranges, bearings, and altitudes of aircraft targets detected by air search radars?

Answer 42

Height-finding

Question 43

Which type of radar system provides the information used to guide a missile to a hostile target called?

Answer 43

Guidance