Vol 2 Weather Radar Ch 1

1.

1 point

The technique the radar uses to compare the frequency of each new pulse with that of the
pulse immediately preceding it is known as

frequency processing.

velocity aliasing.

pulse pair processing

pulse check.

2.

1 point

Widespread low spectrum width values with isolated areas of higher values is most likely
indicative of

lightning

embedded storms

anomalous propagation

icing

3.

1 point

The Doppler dilemma is a tradeoff between

speed and direction.

range and velocity

height and speed

range and height.

4.

1 point

Side lobes can cause

subrefraction

ground clutter

beam blockage.

superrefraction.

5.

1 point

Which wavelength is best for the detection of small water droplets?

3 cm

7 cm

5 cm

10 cm

6.

1 point

Another term for second-trip echoes is

range folding

pulse paired processing.

velocity aliasing.

pulse repetition frequency.

7.

1 point

An unusual straightening of the radar beam upward best defines

superrefraction.

ducting.

subrefraction

second trip echoes.

8.

1 point

Superrefraction is when the curvature of the radar beam is

zero.

greather than the earth's curvature

parallel to the earth’s curvature.

less than the earth’s curvature.

9.

1 point

Range resolution depends on

wavelength.

beam width.

pulse repetition frequency.

pulse length

10.

1 point

How does the beam width vary with the wavelength; how does it vary with the diameter of
the antenna?

Directly; directly.

Inversely; inversely.

Inversely; directly.

Directly; inversley

11.

1 point

The spectrum width product is useful for the early detection of thunderstorm development
because

the detection of high spectrum widths may be indicative of currents present in a convective atmosphere.

the spectrum width product has not been identified for this use.

it scans the mid-levels of the atmosphere for pockets of moisture.

it is more sensitive than base reflectivity and can display the first occurrence of moisture.

12.

1 point

The ability of the radar to differentiate between two closely spaced targets at the same range
and bearing but at different elevations depends on

beam length.

beam illumination.

beam width

wavelength.

13.

1 point

Subrefraction effects the radar’s displayed height values by making display height values

underestimated

off an amount equal to the target's range

correct

overestimated

14.

1 point

The amount of time it takes the radar to transmit one pulse is the

pulse length

propagation.

wavelength.

listening time.

15.

1 point

The actual wind speed is determined if the flow of wind is

at a 15° angle to the radar beam axis.

perpendicular to the radar beam axis.

parrallel to the radar beam axis

at a 45° angle to the radar beam axis.

16.

1 point

The number of cycles per a given unit of time is called

wavelength

a hertz.

propagation.

frequency

17.

1 point

What will the 2.2nm (resolution) reflectivity product display, when the values of the four
consecutive.54nm data bins are 23, 24, 30, and 26?

26

24

30

27

18.

1 point

Which wavelength would be best for interrogating a large thunderstorm?

10.7 cm

2.0 cm

7.2 cm

5.4 cm

19.

1 point

The factor that allows a Doppler radar to remember the frequency of transmitted energy for
later comparison to returning energy is

redundancy.

coherency

dipole processing.

velocity dealiasing.

20.

1 point

Which action is an effective means of decreasing velocity aliasing?

Decrease the pulse repetition frequency.

Decrease the antenna gain (power).

Increase the pulse repetition frequency

Increase the antenna gain (power).

21.

1 point

While performing a radar metwatch, the operator notices a storm that has increased from 40
to 43 dBZs at one elevation slice. The operator must assume the intensity of this storm has

not changed

not changed significantly

doubled

tripled

22.

1 point

What does subrefraction do?

Causes anomalous propagation.

Reduces the maximum range of detection of low-level targets

Usually occurs at night under conditions of strong radiational cooling.

Produces ducting.

23.

1 point

What limits velocity detection in a Doppler radar?

Pulse length.

Wavelength

Spectral shape.

Beamwidth.

24.

1 point

Under which condition is anomalous propagation of the radar beam most likely to occur?

During abnormal atmospheric conditions

Heavy precipitation.

When the radar is improperly tuned.

When the antenna is at high elevation angles.

25.

1 point

The ability of the radar to distinguish between two targets at the same range but at
approximately the same direction from the radar is called

beam resolution.

range resolution.

bearing resolution

elevation resolution.

26.

1 point

An electrical current passing through a wire coiled around a metal bar that induces a
magnetic field is called

frequency.

a dipole.

polarization

electromagnetism

27.

1 point

As electromagnetic waves are emitted from radar and travel through the atmosphere, some of
their energy is lost. What is the loss of energy due to interaction with atmospheric phenomena
called?

Propagation.

Distortion.

Frequency shift.

Attenuation

28.

1 point

When using weather radar to measure the intensity of precipitation, the presence of both
liquid and frozen scatterers may

increase the accuracy of the measurement due to Rayleigh scattering.

increase the power returned due to beam broadening.

decrease the accuracy of the measurement due to beam distortion.

decrease the accuracy of the measurement because the radar equation does not handle mixed precipitation.

29.

1 point

Computation of the equivalent reflectivity factor (Ze) depends on

average returned power, range to target, and a set of known factors called the "radar constant."

decibel values produced by the WSR–88D processors.

maximum returned power, the diameter of the antenna, and the logarithm of their ratio.

each specific weather situation, and can rarely be computed accurately.

30.

1 point

The spectral slope of the Doppler spectrum of a large thunderstorm with hail appear

broad and sharp

narrow and flat.

broad and flat.

narrow and sharp.

31.

1 point

What decides the minimum range of the radar?

Pulse Length

Antenna rotation.

Pulse repetition frequency.

Listening time.

32.

1 point

When choosing an operating wavelength for a radar, it is dependent upon the

intended use

cloud type predominating in the area.

amount of emitted energy.

distance to the target.