# The Micro-Doppler Effect in RadarRF Cafe Quiz #42

All RF Cafe quizzes would make perfect fodder in 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.

Note: Some material based on books have quoted passages.

This quiz is based on the information presented in "The Micro-Doppler Effect in Radar," by Victor C. Chen .

1.  What is the micro-Doppler effect?

a)  An oscillatory motion in addition to a bulk motion
b)  Micron-scale Doppler effects
c)  Large-scale nano-Doppler effects
d)  High resolution Doppler measurements

2.  Which of these is an image of Christian Doppler?

a)         b)         c)         d)

3.  What is an Euler angle?

a)  Angles of clockwise rotation about the x, y, and z axes.
b)  Angles of counterclockwise rotation about the x, y, and z axes.
c)  Angles of RF conduction
d)  Angles of dangles

4.  Which of the following are mechanisms for producing micro-Doppler shift?

a)  Vibration
b)  Rotation
c)  Coning motion
d)  All the above

5.  In the case of a rotating helicopter blade on a stationary aircraft, which Doppler frequency
graph would be correct?

a)             b)

c)             d)

6.  In figure "a" from question 5, why is a plateau over a range of Doppler frequencies formed
in the blade signature rather than a single frequency?

b)  Blade speed varies along the span, increasing toward the tips
c)  Blade speed varies along the span, decreasing toward the tips
d)  Wobble along the span

7.  What is the Denavit-Hartenberg (D-H convention)?

a)  A quantum mechanics-based micro-Doppler model
b)  A way to describe static models as dynamic
c)  A mathematical translation of aircraft micro motion
d)  A kinematic representation of human body links and joints

8.  When analyzing articulated locomotion (animal
walking, bird wing flapping, etc.), what is
commonly assumed to describe the style of
sinusoidal motion?

a)  Orthogonal equations
b)  Newtonian motion
c)  Harmonic oscillations
d)  Special relativity

9.  What is the difference between bipedal and

10.  Which parameters can be extracted from micro-Doppler signatures of targets?

a)  Time and frequency
b)  Magnitude and phase of frequency shifts
c)  Position and direction
d)  All the above