Af Cdc Vol. 2 Set 1

Front 1

An electrical current passing through a wire coiled around ametal bar that induces a magnetic field iscalled

Back 1

Electromagnetism

Front 2

Which wavelength is best whenyou are trying to detect light to moderate rain?

Back 2

3 cm

Front 3

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

Back 3

5cm or greater

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 andtravel through the atmosphere, some of their energy is lost. What is the loss of energybecause of the interaction with atmospheric phenomena called?

Back 5

Attenuation

Front 6

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

Back 6

Wavelength of the emitted radio waves and size andcomposition 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 rangeof 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 thewavelength; how does it vary with the diameter of the parabolicreflector 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 when the radar can distinguish between two targets at the same range, but different direction from the radar?

Back 12

Bearing

Front 13

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

Back 13

Beam width

Front 14

Range resolution depends on

Back 14

Pulse length

Front 15

Side lobes can cause side effects. What is an example of one?

Back 15

Ground clutter

Front 16

Super refraction is when the curvature of the radar beam is

Back 16

Greater than the curvature of the Earth

Front 17

An effect of super refraction is the displayed height values are

Back 17

over estimated

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 "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 that the intensity of the 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 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 are required for high velocity measurements and long ranges?

Back 26

High pulse repetition frequencies are required for high velocity measurements and low pulse repetition frequencies are required for low pulse repetition frequencies

Front 27

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

Back 27

Broad and flat

Front 28

What is the Doppler Spectrum?

Back 28

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

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 thunderstorms

Front 31

Th e beam of the WSR-88D is approximately

Back 31

1.0 degree

Front 32

Which subcomponent of the radar data acquisition takes raw analog data from the receiver and processes it into a digital database?

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

Front 35

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

Back 35

5

Front 36

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

Back 36

450 hours

Front 37

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

Back 37

Master system control function

Front 38

Who owns the Master system control function (MSCF) at a majority of CONUS locations?

Back 38

National Weather Service

Front 39

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

Back 39

By the narrowband communication link

Front 40

What is the MAXIMUM number of workstations a large OPUP can consist of?

Back 40

10

Front 41

Which system supports direct connections to up to seven WSR-88D's?

Back 41

Medium OPUP

Front 42

The 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 OPUP product display window can display up to how many windows per screen?

Back 43

12

Front 44

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

Back 44

+18 dBZ

Front 45

Where would you look for a hook echo signature?

Back 45

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

Front 46

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

Back 46

Its 10cm wavelength can see through stratiform precip because less attenuation

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 reflectivity

Front 49

When the Doppler zero line has a noticeable S-shape 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

What is not a use of the composite reflectivity product?

Back 54

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

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

What procedure is a PRIMARY use for the layered composite reflectivity maximum 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 a layered composite reflectivity product?

Back 57

Strong reflectivity values less than 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 the user selectable composite reflectivity?

Back 59

Composit reflectivity is produced by using the entire volume scan

Front 60

What statement can be made concerning ground clutter?

Back 60

It effects lower elevations and has a low radial velocity and spectrum width

Front 61

What are three processing regions of the layered composite reflectivity maximum (LRM) anomalous propagation removed algorithm?

Back 61

Omit all, accept if, reject if

Front 62

As the strength of the updraft in the storms increases, the vertically integrated liquid values of that storm (decrease/increase)?

Back 62

increase

Front 63

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

Back 63

Reflectivity data converted into liquid water content values

Front 64

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

Back 64

Lower values will be displayed

Front 65

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

Back 65

Base reflectivity

Front 66

The echo tops 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) algorithms?

Back 67

It compares the areal coverage of echoes at the 0.5 and 1.5 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

24 hours.

Front 72

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

generated for:

Back 72

30 hours

Front 73

When is the only time snow products are useful?

Back 73

During dry snow 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 ( 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 0C and –20C

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