Week 1 Theory

Question 1

Speed of light

Answer 1

3x108 m/s
162,000 nm/s
182,000 miles/s

Question 2

Three parts of EW

Answer 2

Attack
Support
Protection

Question 3

Divisions of Electronic Attack

Answer 3

Jamming
Deception
Neutralisation

Question 4

Divisions of Electronic Support

Answer 4

Warning

SIGINT

Question 5

Divisions of Electronic Protection

Answer 5

EMCON
Masking
Hardening
Wartime Reserve Modes

Question 6

Types of Polarisation

Answer 6

Random
Linear
Circular

Question 7

What is Isotropic distrubution

Answer 7

EM energy propagating equally in all directions

Question 8

What is attenuation caused by?

Answer 8

Absorption or scattering

Question 9

What is diffraction

Answer 9

Bending of waves around edges of objects

Lower wavelength=greater diffraction

Question 10

What is Reflection

Answer 10

A waves angle of incidence is equal to its angle of reflection

Question 11

What is refraction

Answer 11

Speed of a wave varies as it goes through a medium

Waves are bent towards the earth

Question 12

What are the wave types

Answer 12

Ground wave (surface and space)

Skywave

Question 13

What are the two transmitter types

Answer 13

Oscillator

Amplifier

Question 14

What are the 3 transmitter devices

Answer 14

Magnetron
Travelling Wave Tube
Field Effect Transistor

Question 15

What parts of a wave can be modulated?

Answer 15

Amplitude
Frequency
Phase

Question 16

Parts of a Transmitter

Answer 16

Synchroniser-modulator-transmitter

Duplexer-antenna

Display-receiver

Question 17

What does Frequency affect

Answer 17

Range-attenuation

Antenna size

Question 18

What does PRF affect

Answer 18

Date rate

MUR

Question 19

What does pulse width affect

Answer 19

Average power

Minimum detection range(MDR)

Question 20

Power

Answer 20

Range

Question 21

What does Beam width affect

Answer 21

Angular discrimination
Beamshape
Freq

Question 22

What does ARP affect

Answer 22

Max detection range, data rate

Question 23

3 types of Radar display

Answer 23

Plan position Indicator
B scope
A scope

Question 24

What should a receiver do?

Answer 24

Intercept
Process
Identify
Display

Question 25

Parts of a reciver

Answer 25

Display—processor—receiver—amplifier—antenna DOA (direction of arrival) resolver

Question 26

What is Signal to noise Ratio

Answer 26

Unit less value resulting from a specified signal being divided by a corresponding noise signal

Question 27

What is Bandwidth

Answer 27

Difference between the upper and lower frequencies of a signal

Question 28

Sources of external noise

Answer 28

Interference Ground Weather Jamming

Question 29

Sources of Internal noise

Answer 29

Equipment noise, transmission noise, antenna noise

Question 30

Scan Types

Answer 30

Circular Sector Raster Complex

Question 31

Antenna components

Answer 31

Feed Reflector Transmitting medium (waveguide, coaxial cable)

Question 32

What is a cosecant squared beam

Answer 32

Reflector shaped so there is more gain at longer range which means long range targets have the same intensity as close range Maritime surveillance

Question 33

What is tapered illumination?

Answer 33

Reduces sidelobes to put more energy down the main beam

Question 34

Two types of feed

Answer 34

Circular-pencil beam | Rectangular-fan beam

Question 35

What does a cassegrain radar do

Answer 35

Has a reflector that changes the polarisation of the radio wave to eliminate a null in the centre of the radar

Question 36

What is gain

Answer 36

A measure of an antennas efficiency to focus a beam in a certain direction

Question 37

Two types of electronically scanned arrays

Answer 37

Passive -one transmitter feeding multiple antennas | Active-multiple tx and rx

Question 38

Types of beam steering

Answer 38

Frequency | Phase

Question 39

What does DOA stand for

Answer 39

Direction of arrival

Question 40

4 parts of an elipse

Answer 40

Major axis Minor axis Orientation (bearing from north) Center point

Question 41

Ways to measure DOA

Answer 41

Directional antenna scanning -360° Amplitude comparison Phase comparison

Question 42

A band

Answer 42

0.03-0.25

Question 43

B band

Answer 43

0.25-0.5

Question 44

C band

Answer 44

0.5-1

Question 45

D band

Answer 45

1-2

Question 46

E band

Answer 46

2-3

Question 47

F band

Answer 47

3-4

Question 48

G band

Answer 48

4-6

Question 49

H band

Answer 49

6-8

Question 50

I band

Answer 50

8-10

Question 51

J band

Answer 51

10-20

Question 52

K band

Answer 52

20-40

Question 53

L band

Answer 53

40-60

Question 54

M band

Answer 54

60-100