Module 4_2 Quiz

1. Which of the following is a true statement about evaporation ducts?

a) They occur about 10% of the time over the ocean.
b) They primarily affect RF transmissions at frequencies less than 3 GHz.
c) They decrease radar clutter.
d)All of the above (a,b,c) are true.
e) None of the above are true.

2. What is the best strategy for radar operators to use to maximize the likelihood of detecting a target when an evaporation duct is present?

a) Always keep the radar sensitivity setting high to maximize surface scatter effects.
b) Always keep the radar sensitivity low to minimize surface scatter effects.
c) Decrease the sensitivity when the evaporation duct is weak and increase the sensitivity when the evaporation duct is strong.
d) Increase the sensitivity when the evaporation duct is weak and decrease the sensitivity when the evaporation duct is strong.
e) Never change the radar settings, as this may confuse the next operator on duty.

3. What is the minimum trapped frequency for an evaporation duct that extends to 24.3 meters?

a) 15 GHz.
b) 3000 GHz
c) 3 GHz
d) No set frequency. It depends on transmission power.
e) No set frequency. It depends on duct strength (i.e. change in M from surface to duct top).