1W051N Volume 2 Unit Review Questions

Front 1

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

Back 1

electromagnetism

Front 2

Which wavelength is best when you are trying to detect a light to moderate rain?

Back 2

3 centimeters

Front 3

Which wavelength would be best for you to use when large thunderstorm or hurricanes frequently occur?

Back 3

10.7

Front 4

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

Back 4

frequency

Front 5

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

Back 5

Attenuation

Front 6

What are the two related factors that attenuation of radar waves depend on?

Back 6

Wavelength of the emitted radio waves and size and composition of the particle encountered by these waves.

Front 7

The amount of time it takes the radar to send one pulse is known as

Back 7

pulse length

Front 8

What decides the minimum range of the radar

Back 8

pulse length

Front 9

Another term for second-trip echoes is

Back 9

range folding

Front 10

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

Back 10

Directly; inversely

Front 11

Sample volume is equal to

Back 11

one-half the pulse length and beam diameter

Front 12

What kind of resolution is it called when the radar can distinguish between two targets at the same range but different directions from the radar?

Back 12

Bearing

Front 13

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

Back 13

beam width

Front 14

Range resolution depends on

Back 14

pulse length

Front 15

Side lobes can cause certain side effects. Which of these is one of the side effects?

Back 15

Ground clutter

Front 16

Superrefraction is when the curvature of the radar beam is

Back 16

greater than the Earth's curvature

Front 17

Another effect of superrefraction is the displayed height values are

Back 17

overestimated

Front 18

Straightening of the radar beam upward best defines

Back 18

subrefraction

Front 19

What does subrefraction do?

Back 19

Reduces the maximum range of detection of low-level targets.

Front 20

Computation of the equivalent reflectivity factor (Ze) depends on

Back 20

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

Front 21

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

Back 21

doubled.

Front 22

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

Back 22

coherency

Front 23

The WSR–88D has only one antenna, it only measures the component of wind that is

Back 23

parallel to the radar beam

Front 24

Which action is an effective means of decreasing velocity aliasing?

Back 24

Increase the pulse repetition frequency.

Front 25

The Doppler dilemma is a tradeoff between

Back 25

range and velocity

Front 26

What kind of pulse repetition frequencies (PRF) are required for high velocity measurements and long ranges?

Back 26

High PRFs are required for high velocity measurements, and low PRFs are required for long ranges.

Front 27

What is the Doppler spectrum?

Back 27

The distribution of power received by the radar at each frequency within a sample volume.

Front 28

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

Back 28

broad and flat

Front 29

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

Back 29

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

Front 30

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

Back 30

embedded storms.

Front 31

The beam width of the WSR–88D is approximately

Back 31

1.0°.

Front 32

Which subcomponent of the radar data acquisition (RDA) takes raw analog data from the
receiver and process it into a digital base data?

Back 32

Signal processor.

Front 33

Solid (ground clutter) return has very low spectrum width values ranging from

Back 33

0.1 to 0.5m/sec

Front 34

Data thresholding occurs at the

Back 34

radar data acquisition (RCA)

Front 35

How many elevation slices does both volume coverage pattern (VCP) 31 and VCP 32 (clear
air mode) complete in ten minutes?

Back 35

five

Front 36

How many hours does the JAZ drive have the capability to hold?

Back 36

450

Front 37

Control of the radar product generator (RPG) is accomplished from a computer terminal
known as the

Back 37

Master system control function (MSCF).

Front 38

Who owns the MSCF at a majority of the CONUS locations?

Back 38

National Weather Service (NWS).

Front 39

How is data transferred from the radar product generator (RPG) to an Open Principal User
Processor (OPUP)?

Back 39

By the narrowband communications link.

Front 40

What is the maximum number of workstations a large Open Principal User Processor
(OPUP) can consist of?

Back 40

10

Front 41

Which system supports direct connections to up to seven WSR–88Ds?

Back 41

medium OPUP

Front 42

The open principal user processor (OPUP) uses which operating system and user interaction
is done through the common desktop environment (CDE) Graphic User Interface (GUI) by

Back 42

Unix; keyboard and mouse

Front 43

The open principal user processors (OPUP) product display window can display up to how
many windows per screen?

Back 43

12

Front 44

Which value is considered non-precipitable and are often just cloud droplets?

Back 44

+18dBZ

Front 45

Where would you look for a hook echo signature?

Back 45

In the right rear quadrant of the trailing half of the parent echo

Front 46

Embedded thunderstorms are detected by the WSR–88D quite well because

Back 46

its 10cm wavelength can see through the stratiform precipitation because less attenuation occurs

Front 47

Outflow boundaries may be seen on the WSR–88D even when no clouds are present
because

Back 47

of the gradient in the refractive index.

Front 48

Which product is used to detect and locate motions in and around potentially severe
weather-producing storms?

Back 48

Base mean radial velocity.

Front 49

When the Doppler zero line has a noticeable S-shaped pattern, winds are considered

Back 49

veering with height

Front 50

When the radar detects pure cyclonic rotation, the Doppler zero line is oriented

Back 50

parallel to the viewing direction

Front 51

The spectrum width product is most effective when

Back 51

used with other products

Front 52

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

Back 52

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

Front 53

Data collected for generation of the composite reflectivity product is derived from

Back 53

all elevation slices

Front 54

Which statement is not a use of the composite reflectivity (CR) product?

Back 54

It can be used to show the 3-D structure of the reflectivity pattern.

Front 55

The melting level is displayed on the composite reflectivity product as

Back 55

multiple rings of enhanced reflectivity around the radar data acquisition (RDA).

Front 56

Which procedure is a primary use for the layered composite reflectivity maximum (LRM)
product?

Back 56

Quickly identifying stronger storms and areas with a greater potential for convection.

Front 57

Which condition indicates an intense updraft and strong likelihood for severe
weather on the layered composite reflectivity product?

Back 57

Strong reflectivity values (>50 dBZ) in the high altitude layer.

Front 58

What is the minimum depth layer for the layered composite reflectivity product?

Back 58

1,000 feet

Front 59

What is the major difference between composite reflectivity and user selectable composite
reflectivity?

Back 59

Composite reflectivity is produced by using the entire volume scan.

Front 60

Which is a true statement concerning ground clutter?

Back 60

Ground clutter principally affects lower elevations, and has low radial velocity and spectrum width.

Front 61

Identify the three processing regions of the layered composite reflectivity maximum (LRM)
anomalous propagation removed (APR) algorithm.

Back 61

omit all, accept if, and reject if

Front 62

As the strength of the updraft in a storm increases, the vertically integrated liquid (VIL)
values of that storm

Back 62

increase

Front 63

Vertically integrated liquid (VIL) algorithm display VIL values for storms based on

Back 63

reflectivity data converted to liquid water content values.

Front 64

A strongly tilted storm may cause what kind of vertically integrated liquid (VIL) values to
be displayed?

Back 64

lower

Front 65

The echo tops (ET) product is based on data from what other product?

Back 65

base reflectivity

Front 66

The echo tops (ET) product computes echo top height by using

Back 66

2.2 x 2.2nm grid boxes.

Front 67

What is the function of the tilt test in the hybrid scan reflectivity (HSR) algorithm?

Back 67

It compares the areal coverage of echoes at the 0.5 degrees and 1.5 degrees elevation slices.

Front 68

The storm total precipitation (STP) product provides continuously updated information on
precipitation accumulations within how many nautical miles of the radar?

Back 68

124

Front 69

A limitation of the STP product is that it

Back 69

has trouble with small-scale features.

Front 70

What information is included in the attribute table that accompanies the user selectable
precipitation (USP) product?

Back 70

The total number of hours used to build the product.

Front 71

How long is the database for the user selectable precipitation (USP) product?

Back 71

30 hours

Front 72

What is the maximum number of hours that the user selectable precipitation product can be
generated for:

Back 72

24

Front 73

When is the only time snow products are useful?

Back 73

during dry snowfall events

Front 74

What are the typical strength rank values for a well defined mesocyclone?

Back 74

between five and nine

Front 75

The mesocyclone detection (MD) product can be graphically displayed, what symbol is
displayed for a circulation having a strength rank less than 5?

Back 75

a thin yellow open circle

Front 76

The graphic symbol for a tornadic vortex signature (TVS) is a

Back 76

red-filled, inverted, isosceles triangle

Front 77

The graphic symbol for an elevated tornadic vortex signature (ETVS) is

Back 77

red, open, inverted, isosceles triangle.

Front 78

The maximum shear associated with a tornadic vortex signature (TVS) must be at least

Back 78

36m/s (approximately 72 knots) anywhere in the circulation.

Front 79

Which statement is not a limitation of the tornadic vortex signature (TVS) product?

Back 79

It only identifies TVSs associated with mesocyclones.

Front 80

The total number of vertical wind profiles that can be displayed on a single velocity azimuth
display winds profile (VWP) is up to

Back 80

11

Front 81

The velocity azimuth display (VAD) wind profile (VWP) displays

Back 81

the true wind speed and direction

Front 82

The color-coded root mean square (RMS) of displayed velocity azimuth display (VAD)
winds is related to the

Back 82

reliability of the winds

Front 83

Data thresholds for the vertical winds profile (VWP) can be changed

Back 83

by the master system control function (MSCF)

Front 84

The velocity azimuth display (VAD) winds profile (VWP) can detect features such as

Back 84

wind shifts and jet streams

Front 85

The SRM/SRR (storm relative mean radial velocity (map) product/storm relative mean
radial velocity (region) product) depends on what algorithm?

Back 85

storm tracking

Front 86

The velocity cross-section product is limited to a range within

Back 86

124nm

Front 87

Resolution of cross-section products

Back 87

remain constant

Front 88

Which algorithm is the output of the storm cell segments algorithm directly sent to?

Back 88

storm cell centroids

Front 89

The Storm Cell Identification and Tracking (SCIT) algorithm can track how many
individual storm cells?

Back 89

100

Front 90

How does the storm cell tracking algorithm handle a storm cell centroid when it can’t
correlate with a storm cell centroid from a previous volume scan?

Back 90

It labels the storm as “NEW” and doesn’t forecast a track.

Front 91

What determines the length of a forecast made by the storm position forecast algorithm?

Back 91

Accuracy of previous volume scan’s forecast.

Front 92

The storm track information (STI) product algorithm provides data on

Back 92

past, present, and future locations of thunderstorms.

Front 93

How many minutes does the linear motion feature enable the radar user to manually
compute a forecast position?

Back 93

60

Front 94

What are the three estimates that the hail detection algorithm provides?

Back 94

Probability of hail, probability of severe hail, and maximum expected hail size.

Front 95

The probability of severe hail algorithm will look for hail

Back 95

>3/4 inch.

Front 96

What information needs to be routinely updated to increase the hail detection algorithm’s
performance?

Back 96

Mean sea level (MSL) altitudes for 0 degrees C and –20 degrees C.

Front 97

What is the maximum number of volume scans used for history in the cell trends graphic
product?

Back 97

10

Front 98

Which dual polarization product is the ratio of the reflected horizontal and vertical power
returns and is expressed in decibels?

Back 98

differential reflectivity (Zdr)

Front 99

Which dual polarization product is a dimensionless measure of the similarity between the reflected horizontal and vertical power returns within each radar pulse volume?

Back 99

correlation coefficient (CC)

Front 100

The outer dashed circle on the melting layer product represents the

Back 100

point along the radial beyond which the beam is entirely above the melting layer.