Shared Flashcard Set

Details

CDC 5 level
Weather Radar
110
Meteorology
Undergraduate 1
12/28/2011

Additional Meteorology Flashcards

 


 

Cards

Term
An electrical current passing through a wire coiled around a metal bar that induces a magnetic field is called:
Definition
electromagnetism
Term
Which wavelength is best for the detection of small water droplets?
Definition
3 cm
Term
Which wavelength would be best for interrogating a large thunderstorm?
Definition
10.7 cm
Term
When choosing an operating wavelength for radar, it is dependent upon the:
Definition
intended use
Term
The number of cycles per a given unit of time is called:
Definition
frequency
Term
As electromagnetic waves a emitted from radar and travel through the atmosphere, some of their energy is lost. What is the loss of energy due to interaction with atmopsheric phenomena called?
Definition
Attenuation
Term
The amount of time it takes the radar to transmit one pulse is the:
Definition
pulse length
Term
What decides the minimum range of the radar?
Definition
pulse length
Term
How does the beam width vary with the wavelength; how does it vary with the diameter of the antenna?
Definition
Directly; inversely
Term
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:
Definition
bearing resolution
Term
The ability of the radar to differentiate between two closely spaced targets at the same range and bearing but at different elevations depends on:
Definition
beam width
Term
Range resolution depends on:
Definition
pulse length
Term
Side lobes can cause:
Definition
ground clutter
Term
Another term for second-trip echoes is:
Definition
range folding
Term
Under which condition is anomalous propagation of the radar beam most likely to occur?
Definition
During abnormal atmospheric conditions
Term
Superrefraction is when the curvature of the radar beam is:
Definition
greater than the earth's curvature
Term
An unusual straightening of the radar beam upward best defines:
Definition
subrefraction
Term
What does subrefraction do?
Definition
Reduces the maximum range of detection of low-level targets.
Term
Subrefraction effects the radar's displayed height values by making display height values:
Definition
underestimated
Term
When using weather radar to measure the intensity of precipitation, the presence of both liquid and frozen scatterers may:
Definition
decrease the accuracy of the measurement because the radar equation does not handle mixed precipitation.
Term
Computation of the equivalent reflectivity factor (Z) depends on:
Definition
average returned power, range to target, and a set of known factors called the "radar constant."
Term
While preforming 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:
Definition
doubled.
Term
What will the 2.2 nm (resolution) reflectivity product display, when the values of the four consecutive .54 nm data bins are 23,24,30, and 26.
Definition
30
Term
The factor that allows a Doppler radar to remember the frequency of transmitted energy for later comparison to returning energy is:
Definition
coherency
Term
The technique the radar uses to compare the frequency of each new pulse with that of the pulse immediately preceding it is known as
Definition
pulse pair processing
Term
The actually wind speed is determined if the flow of wind is:
Definition
parallel to the radar beam axis
Term
What limits velocity detection in a Doppler radar?
Definition
Wavelength
Term
Which action is an effective means of decreasing velocity aliasing?
Definition
Increase the pulse repetition frequency.
Term
The Doppler dilemma is a tradeoff between:
Definition
range and velocity
Term
The spectral slope of the Doppler spectrum of a large thunderstorm with hail appear:
Definition
broad and flat
Term
The spectrum width product is useful for the early detection of thunderstorm development because:
Definition
the detection of high spectrum widths may be indicative of currents present in a convective atmosphere.
Term
Widespread low spectrum width values with isolated areas of higher values is most likely indicative of:
Definition
embedded storms.
Term
The beam width of the WSR-88D is approximately:
Definition
1.0
Term
Processing of ground clutter and range unfolding are functions of the:
Definition
radar data acquisition.
Term
Base data is collected by the:
Definition
radar data acquisition.
Term
Two distinct properties common to most ground clutter are:
Definition
small spectrum width and near zero Doppler velocity.
Term
How many elevation slices does both VCP 31 and VCP 32 (clear air mode) complete in ten minutes?
Definition
Five.
Term
Control of the radar product generator is accomplished from a computer terminal known as what?
Definition
RDA/RPG remote access terminal
Term
The radar product generator uses what method to dealias velocity data before it is used by the meteorological algorithms?
Definition
eilts dealiasing technique
Term
The clear-air analysis task contains which two algorithms?
Definition
Velocity azimuth display and velocity volume processing algorithms.
Term
The radar product generator provides:
Definition
alert processing.
Term
The workstation is the interface to which processors in the Weather Surveillance Radar 1988-Doppler system?
Definition
Display and graphic processors
Term
The primary interface used to request, control, and manipulate Weather Surveillance Radar 1988-Doppler system products is the:
Definition
graphic tablet and puck.
Term
The principal user with dedicated communications to a WSR-88D unit is called:
Definition
an assocaited user.
Term
The two ways to select products from the principal user processor database are by using the:
Definition
graphic tablet and puck and through the applications terminal.
Term
Which procedure is not a way to request products on the principal user processor?
Definition
Product-parameter selection list
Term
A request for product not on the current routine product set list is called:
Definition
a one-time product request.
Term
Who determines the various alert thresholds for meteorological phenomena?
Definition
Local unit radar committee.
Term
What are the different group of alert thresholds?
Definition
Volume group, forcast group and grid group.
Term
Which archive levels are at the radar data acquisition?
Definition
I and II.
Term
Which archive level is the most important and useful because it allows the total recreation of a weather scenario?
Definition
Archive level II.
Term
Which archive level can only record those products being received at the principal user processor?
Definition
Archive level IV.
Term
The open principal user processor software concepts replaces the graphics tablet and puck because it uses:
Definition
Graphics user interface.
Term
The main difference between an open principal user processor (OPUP) used at an Opertional Weather Squadron and an OPUP used at a Combat Weather Team is:
Definition
capacity of the OPUP.
Term
Weather Flights that use an open principal user processor are limited when compared to an OPUP at an Operational Weather Squadron because the WF has:
Definition
just one RDA.
Term
For the WSR-88D to generate a base reflectivity product, the antenna must complete:
Definition
one elevation slice.
Term
The line echo wave pattern (LEWP) signature should signal the radar operator that:
Definition
a favorable environment exists for severe weather development.
Term
Embedded thunderstorms are detected by the WSR-88D quite well because:
Definition
its 10cm wavelength can see through the stratiform precipitation that tends to hide the storms on 5cm radars.
Term
Outflow boundaries may be seen on the WSR-88D even when no clouds are present because:
Definition
a gradient in the refractive index due to density differences will exist with the boundary.
Term
Which product is used in the detection and location of rotating thunderstorms and in determining wind field characteristics.
Definition
Base mean radial velocity.
Term
When the Doppler zero line has a noticeable forward S-shaped pattern, winds are considered:
Definition
veering with height.
Term
When the radar detects pure cyclonic rotation, the doppler zero line is oriented:
Definition
parallel to the viewing direction.
Term
Which concept should be considered when trying to determine hail size?
Definition
strength of the updraft.
Term
The spectrum width product is most effective when:
Definition
used with other products.
Term
The spectrum width product is useful for the early detection of thunderstorm development.
Definition
the detection of high spectrum widths may be indicative of currents present in a convective atmosphere.
Term
Data collected for generation of the composite reflectivity product is derived from:
Definition
all elevation slices.
Term
Which statement is not a use for the composite reflectivity (CR) product?
Definition
It can be used to show the 3-D structure of the reflectivity pattern.
Term
Which procedure is a primary use for the layered composite reflectivity maximum product?
Definition
Quickly identifying strong storms and areas with a greater potential for convection.
Term
Identify the three processing regions of the layered composite reflectivity maximum (LRM) anomalous propagation removed (APR) algorithm.
Definition
Omit all, accept is, and reject if.
Term
Vertically Integrated Liquid (VIL) algorithms display VIL values for storms based on:
Definition
reflectivity data converted to liquid water content.
Term
A strongly tilted storm may cause what kind of vertically integrated liquid (VIL) values to be displayed.
Definition
Lower
Term
In comparison to the vertically integrated liquid (VIL) grid boxes, severe weather porbability (SWP) grid boxes are:
Definition
Larger
Term
Although severe weather probability (SWP) is calculated using vertically integrated liquid (VIL), occasionally VIL values will drop dramatically while SWP values change little or not at all. This is caused by:
Definition
storm tilt.
Term
The echo tops (ET) product is based on data from what other product?
Definition
Base reflectivity
Term
The echo tops (ET) product computes echo top height by using:
Definition
2.2 x 2.2 nm grid boxes
Term
The echo tops (ET) product is very useful in:
Definition
showing the presnce of vertical tilt within a storm.
Term
Which product is best used to determine the accuracy of WSR-88D precipitation products?
Definition
Hybrid scan reflectivity.
Term
What is the function of the tilt test in the hybrid scan reflectivity (HSR) algorithm?
Definition
It compares the areal coverage of echoes at the .5 and 1.5 elevation slices.
Term
The storm total precipitation (STP) product provides continuously updated information on precipitation accumulations within how many nautical miles of the radar?
Definition
124
Term
A limitation of the STP product is that it:
Definition
has trouble with smal-scale features.
Term
Which information is included in the attribute table that accompanies the user selectable precipitation (USP) product?
Definition
the total number of hours used to build the product.
Term
How long is the database for the user selectable precipitation (USP) product?
Definition
30 hours
Term
What is the maximum number of hours that the user selectable precipitation product can be generated for?
Definition
24
Term
The 2-D processor searches for cyclonic shear by identifying:
Definition
pattern vectors
Term
Once the mesocyclone algorithm identifies all pattern vectors, it attempts to consolidate them to form:
Definition
2-D features
Term
The maximum range MESOs can be identified by the mesocyclone algorithm is 110 nm, due to
Definition
a maximum height threshold of 8km
Term
No-data gaps are most prevalent in:
Definition
VCP21
Term
The graphic symbol for a tornadic vortex signature (TVS) is a:
Definition
red filled, inverted, isosceles triangle.
Term
The graphic symbol for an elevated tornadic vortex signature (ETVS) is:
Definition
red, open, inverted, isosceles triangle.
Term
Concerning tonadic vortex signatures (TVS), localized shear should extend several thousand feet and should be present for at least how many elevation slices?
Definition
Two
Term
The velocity azimuth display (VAD) winds profile (VWP) provides:
Definition
a time-height profile of wind velocity at a predetermined range.
Term
The total number of vertical wind profiles that can be dispalyed on a single velocity azimuth dispaly winds profile (VWP) is:
Definition
11
Term
Whenever the velocity azimuth display (VAD) algorithm determines that velocity data for a particular altitude does not meet reliability thresholds, the product displays which symbol for that altitude?
Definition
ND
Term
The color-coded root mean square (RMS) of displayed velocity azimuth display (VAD) winds is related to the:
Definition
reliability of the winds.
Term
If the velocity azimuth display (VAD) algorithm finds no difference between the zero velocity line and the zeroth harmonic, then the offset is zero, and the wind field is:
Definition
uniform
Term
The VAD winds profile (VWP) can detect features such as:
Definition
winds shifts and jet streams.
Term
The storm relative mean radial velocity map and storm relative mean radial velocity region (SRM/SRR) products are derived from the base:
Definition
velocity algorithm.
Term
A limitation causing small features at long distances to go undetected is:
Definition
beam broadening
Term
The velocity cross section is limited to:
Definition
124 nm
Term
Which data collection limitation of the reflectivity cross-section product causes reduced values at long ranges?
Definition
Beam boardening
Term
What is the most important thing to keep in mind when requesting a velocity cross section?
Definition
It must be cut either parallel, or perpendicular to, a radial
Term
Which statement best defines a storm cell segment?
Definition
Contiguous samples volumes along a radial that are greater than or equal to specific reflectivity thresholds.
Term
The most important product used in defining storm segments is:
Definition
base reflectivity
Term
The storm cell centroid algorithm performs best when:
Definition
isolated, well-defined thunderstorms are present.
Term
The SCIT algorithm can track how many individual storm cells?
Definition
100
Term
What determines the length of a forecast made by the storm position forecast algorithm?
Definition
Accuracy of previous volume scan's forecast
Term
The three estimates that the hail detection algorithm provides are:
Definition
probability of hail, probability of severe hail, and maximum expected hail size.
Term
The probability of severe hail algorithm will look for hail:
Definition
> 3/4 inch.
Term
Which product provides information on cell-based VIL, height of maximum reflectivity and maximum reflectivity in the cell?
Definition
storm structure product.
Term
What information does the cell trends product provide for the operator?
Definition
Status of supercells and the potential for microbursts.
Supporting users have an ad free experience!