113 Technical Fundamentals

Question 1

Ehf
Shf
Uhf
Vhf
Hf
Mf
Lf
Vlf
Ulf
Slf
Elf

Answer 1

Ehf 30-300 GHz
Shf 3-30 GHz
Uhf 300 MHz- 3 GHz
Vhf 30-300 MHz
Hf 3-30 MHz
Mf 300 KHz- 3 MHz
Lf 30-300 KHz
Vlf 3-30 KHz
Ulf 300 Hz- 3 KHz
Slf 30-300 Hz
Elf  3-30 Hz

Question 2

Frequency

Answer 2

number of cycles per second, measured in Hz

Question 3

Wavelength

Answer 3

spatial period of the wave- the distance over which the wave’s shape repeats

Question 4

Ducting

Answer 4

trapping of an RF wave between 2 layers of the earth’s atmosphere or between an atmospheric layer and earth

Question 5

Refraction

Answer 5

change in the direction of the wave

Question 6

Multiplexing

Answer 6

a process where multiple analog message signals or digital data streams are combined into one signal over a shared medium

Question 7

Modulation/Demodulation

Answer 7

modulation is the process of conveying a message signal

demodulation is the act of extracting the original information-bearing signal from a modulated carrier wave

Question 8

Bandwidth

Answer 8

a measure of the width of a range of frequencies, measured in Hz

Question 9

Radio Waves

Answer 9

type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light

Question 10

Propagation

Answer 10

the behavior of radio waves when they are transmitted, or propagated, from one point on Earth to another, or into various parts of the atmosphere

Question 11

Azimuth Angle

Answer 11

horizontal angle measured clockwise from a north base line or meridian

Question 12

Elevation Angle

Answer 12

angular height of the sun in the sky measured from the horizontal

Question 13

USB

Answer 13

Upper Sideband- the signal components above the carrier frequency

Question 14

LSB

Answer 14

Lower Sideband- the signal components below the carrier frequency

Question 15

CW

Answer 15

Continuous wave- an electromagnetic wave of constant amplitude and frequency

Question 16

AM

Answer 16

Amplitude Modulation- a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave

Question 17

FM

Answer 17

Frequency Modulation- conveys information over a carrier wave by varying its frequency

Question 18

PRI

Answer 18

Pulse Repetition Interval- the reciprocal of PRF is called PRT, PRI, or IPP, which is the elapsed time from the beginning of one pulse to the beginning of the next pulse

Question 19

RF

Answer 19

Radio Frequency- frequency at which radar operates

Question 20

BW

Answer 20

Bandwidth- difference between the upper and lower cutoff frequencies of a radar receiver, typically measured in Hz

Question 21

PW

Answer 21

Pulse Width- duration of the pulse

Question 22

SCAN

Answer 22

the movement of a radar beam as it searches for objects

Question 23

Bearing

Answer 23

the direction of the line of sight from the radar antenna to the contact

Question 24

Azimuth

Answer 24

compass bearing

Question 25

Elevation

Answer 25

the angle between the horizontal plane and the LOS, measured in the vertical plane

Question 26

Air Search

Answer 26

maintain 360 degree surveillance from the surface of high altitudes, and to detect and determine ranges and bearings of aircrafts targets over relatively large areas

Question 27

Surface search

Answer 27

maintain 360 degree surveillance of the surface

Question 28

Fire Control

Answer 28

RADAR which is designed specifically to provide information to a fire-control system in order to calculate a firing solution

Question 29

OPELINT

Answer 29

locations and readiness

Question 30

TECHELINT

Answer 30

capabilities and limitations

Question 31

Half-duplex

Answer 31

provides for comms in both directions, but only in one direction per time

Question 32

Duplex

Answer 32

composed of two connected parties or devices that can communicate with one another in both directions

Question 33

Simplex

Answer 33

comms in one direction at one time, you cannot send if you are receiving