Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RADAR > RDR - 1 > Flashcards

RDR - 1 Flashcards

1
Q

What does RADAR stand for

A

RADIO DETECTION AND RANGING

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the function of common Radar devices: Magnetron

A
  • The purpose of a magnetron is to convert a high
    energy DC pulse into an extremely high frequency pulse.
  • It was commonly used in airborne RADAR due to its light weight, high efficiency, and small size.
    – P3C APS-115 used a magnetron transmitter.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the function of common Radar devices: Travelling Wave Tube (TWT)

A
  • The TWT is a broadband, low noise amplifier.
  • Its advantage over a magnetron is its low noise factor.
    – P-8 APY-10 use a TWT transmitter.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the function of common Radar devices: Waveguides

A
  • Waveguides are hollow, generally rectangular tubes that guide electromagnetic (EM) energy by reflecting energy off the inside surfaces of the waveguide.
  • Because the cross sectional dimensions of a waveguide must be of the same order as those of a wavelength, use at frequencies below 1 GHz is not normally considered.
  • Waveguide dimensions decrease as the frequency increases.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the function of common Radar devices: Antenna

A
  • An antenna is a device used for radiating radio waves into free space or receiving radio waves from free space.
  • The size and design of antennas vary in accordance with the frequency (or wavelength) used.
  • The length of the antenna must be matched as closely as possible to the wavelength of the carrier waves.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the function of common Radar devices: Antenna Couplers

A
  • An antenna coupler is a device which makes it possible for one or two antennas to do the electrical work of
    many, as opposed to using a separate antenna for each individual wavelength.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the following terms and state their units of measurement: Frequency

A
  • Frequency is the cycles per second of a transmitted signal.
  • Unit of measure – Hertz, (Hz) Mega Hertz (MHz) or Giga Hertz (GHz).

1 Hz = 1 Cycle Per Second

two types
- pulsed RF (Nav Radar)
- Continuous wave (Radio station)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the following terms and state their units of measurement: Pulse Width

A
  • Duration of the transmitted pulse measured from the leading edge to the trailing edge of the pulse.
  • Unit of Measure - Microseconds (µsecs).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the following terms and state their units of measurement: Pulse Repetition Interval (PRI)

A
  • Time period from the leading edge of one pulse to the next leading edge.
  • Unit of measure – micro seconds (µsecs).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the following terms and state their units of measurement: Pulse Repetition Frequency

A
  • Number of pulses transmitted per second.
  • Unit of measure - Hertz (Hz).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the following terms and state their units of measurement: Duty Cycle

A
  • Ratio of Transmitter (Tx) ON time over the total pulse period.
  • Pulse period is measured from the leading edge of the first pulse to the leading edge of the next pulse.
  • No unit of measure – expressed as a percentage.

Duty cycle = Pulse width/Pulse Repetition Interval

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the following terms and state their units of measurement: Peak Power

A
  • The amplitude of the transmitted pulse.
  • Unit of measure - Kilo Watts (KW) or Mega Watts (MW).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the following terms and state their units of measurement: Average Power

A
  • Output power of a transmitter as measured from the start of one pulse to the start of the next pulse.
  • Unit of measure - Watts (W).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the following terms and state their units of measurement: Antenna (AE) Scan Rates

A
  • The speed at which the antenna rotates through 360 degrees.
  • Unit of measure – Seconds Per Rotation (SPR).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain how RADAR range is derived.

A
  • Range is determined by measuring the time taken for the pulse to leave the RADAR antenna, reflect off a target, and then be received back at the RADAR antenna.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Explain how RADAR bearing is derived.

A
  • Bearing is determined by the direction that the antenna is pointing at the time of reception
17
Q

What are the two RADAR Principles?

A
  • A high energy pulse is transmitted.
  • When it strikes an object, a portion of that pulse may be reflected back to the RADAR.
18
Q

Describe Exciter

A
  • Exciter – The purpose of an exciter is to generate a
    continuous, highly stable, low power signal at the
    desired frequency (which is fully selectable) and phase
    for output to the transmitter. A reference signal is also
    sent to the receiver for phase comparison of the
    received pulse.
19
Q

Describe Transmitter

A
  • Transmitter –The purpose of a transmitter is to
    produce the required Radio Frequency (RF) at
    sufficient power levels. Transmitters include
    magnetrons, klystrons and travelling wave tubes
    (TWTs).
20
Q

Describe Duplexer

A
  • Duplexer - The purpose of the Duplexer is to permit the alternate use of the same antenna for both transmission and reception.
21
Q

Describe Antenna

A
  • Antenna - The purpose of the antenna, in a basic pulsed
    RADAR system, is to provide a coupling between free
    space and the transmitter / receiver. The antenna is used
    to transmit RF energy into space, concentrating that
    energy into a narrow beam. The antenna is also used to
    receive energy returned from RADAR targets.
22
Q

Describe Antenna Couplers

A
  • Antenna Couplers - An antenna coupler is a device
    which makes it possible for one or two antennas to do the
    electrical work of many, as opposed to using a separate
    antenna for each individual wavelength.
23
Q

Describe Signal Processor

A
  • Signal Processor - Digitised signals from the receiver
    are fed to the Signal Processor and sorted by range
    and doppler frequency (using a bank of Doppler Filters).
    The Signal Processor filters out ground clutter, and
    automatically detects target echoes. Echo locations are
    stored in a digital memory, then continuously scanned
    for display.
  • Main goal is = Improve the signal to interference ratio
23
Q

Describe Receiver

A
  • Receiver – The purpose of a receiver is to receive the
    weak echo from a target, amplify and present that echo
    to the signal processor in a suitable format for
    processing.
24
Q

Describe RADAR Data Processor (RDP)

A
  • RADAR Data Processor (RDP) - The purpose of the RDP is
    for:
    – Control and performance of routine computations for all RADAR units.
    – System timing.
    – Scheduling operating mode selection e.g. long range
    search, tracking and imaging modes (SAR / ISAR).
    – Antenna stabilisation and control, using aircraft Inertial
    Navigation Unit (INU) inputs.
    – Track acquisition and target tracking.
25
Q

Describe Display

A
  • Display – Provides the operator with a visual representation
    of target echoes.

RADAR (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions