All RF Cafe quizzes would make perfect fodder for employment interviews for technicians or engineers
- particularly those who are fresh out of school or are relatively new to the work world. Come to
think of it, they would make equally excellent study material for the same persons who are going to
be interviewed for a job.
Some of these books used in quizzes are available as prizes
in the monthly RF Cafe Giveaway.
Note: Many answers contain passages quoted in whole or in part from the text.
quiz is based on the information presented in Stimson's
Introduction to Airborne Radar, Third Edition, by Hugh D. Griffiths, Christopher Baker, and David Adamy.
The publisher was not kidding when he stated, "recognizing that people who have an interest in airborne radars
love airplanes, dispersed through the book are photos and renderings of radar-bearing aircraft from all over the world."
If for no other reason, Stimson's book is a good one to leave on your desk or coffee table as a way-cool picture book
for your friends to peruse while visiting. Introduction to Airborne Radar is in every sense a text designed
to turn the electronics neophyte who has a reasonable grasp of algebra and physics into a technician who possesses
a working knowledge of airborne radar (and radar in general) transmitter, receiver, antenna, and processor systems.
The authors teach from first principles about antenna radiation, the decibel, frequency conversion, filtering, signal
processing, target acquisition and tracking, spread spectrum, Doppler shift, radar cross section, electronic countermeasures,
cancelling, platform configurations, and much more. This book is not like the equally vaunted Skolnik
Radar Handbook that is chock full of equations and theoretical discussions, known to make otherwise competent
technophiles curl into a prenatal position while rocking back and forth. It is impossible for a reader to study this
entire book and not be able to participate in an intelligent conversation on radar systems from both a technical standpoint
and a historical perspective. Can you tell I'm impressed?
Note: Some of these books are available as prizes in the monthly
RF Cafe Giveaway; however, this one will
likely remain in my possession for a long time..
1. What is another, more common name for a coherent radar system?
a) Linear frequency radar
b) Linear phase radar
c) Pulse Doppler radar
2. Match the following common radar frequency bands with their central frequencies.
3. In which direction(s) does(do) an antenna's sidelobe(s) exist?
a) Front only
b) Side only
c) Back only
d) All directions
4. What causes a grating lobe in an electronically scanned antenna?
a) Spacing radiating elements at too great of a distance
b) Spacing radiating elements at too small
of a distance
c) Too low radiated power
d) Too high radiated power
5. What is the main advantage of a pulsed radar over a non-pulsed radar?
a) Pulsed radar avoids transmitter leakage issues
b) Pulsed radar allows higher power
Pulsed radar is less expensive that non-pulsed radar
d) Pulsed radar can be used on airborne platforms whereas
6. What is radar cross-section (RCS)?
a) Physical size of the radar unit
b) Physical size of the radar antenna
c) Effective size
of the radar unit and antenna relative to a perfect radar system
d) Effective area of the signal reflecting
surface relative to a perfectly reflecting sphere of the same projected area
7. What is "chirping?"
a) Linear amplitude modulation over the transmit time
b) Linear frequency modulation over the transmit
c) Transmitting one under PAR
d) Radar return of a flock of birds
8. Coherence in radar refers to which of the following?
a) Time of the signal from one pulse to the next
b) Frequency of the signal from one pulse to the
c) Amplitude of the signal from one pulse to the next
d) Phase of the signal from one pulse
to the next
9. What defines bins in a Doppler filter bank?
a) Frequency bands
b) Amplitude ranges
c) Time segments
d) Phase angles
10. What is the name for unwanted returns from the ground?
c) Specular ambiguity
d) Frequency inversion
11. Match each picture with what it represents.
- High accuracy, high precision
- High accuracy, low precision
- Low accuracy, high precision
accuracy, low precision
12. Which type of pulse repetition frequency (PRF) results in unambiguous range?
d) All three
Need some help? Click here for the
answers and explanations.