Week 5 Article Critique

Week 5 Article Critique
Use the Campbellsville University Library databases to do research on peer-reviewed journal articles on the topic of Current and Emerging Technology (do not use Google or Wikipedia).Choose an article that includes all parts listed in the Article Critique Rubric located on the Moodle course page. Download the file in the attachment below totype in your responses, then upload the completed file.*After downloading the word document below, type your responses directly into the word file.
msitm
ATTACHED FILE(S)
*Students should type directly into the chart below.
ARTICLE CRITIQUE

Parts of Article Critique

Student Responses

Your First and Last Name

Author(s) First and Last Name

Article Title

Publication Date: Year (within last 10 years)

Journal Name

Journal Volume

Journal Number

Journal Pages (range, ex. 1-10)

Article Abstract: highlight and copy the exact abstract from the article chosen and paste the abstract here

Takeaway: In a bulleted list, write complete sentences about three things you have learned from the article.
*The takeaway should be written in your own words with no similarity.

·

·

·
Bluestein, H. B., Rauber, R. M., Burgess, D. W., Albrecht, B., Ellis, S. M., Richardson, Y. P., Jorgensen, D. P., Frasier, S. J., Chilson, P., Palmer, R. D., Yuter, S. E., Lee, W.-C., Dowell, D. C., Smith, P. L., Markowski, P. M., Friedrich, K., & Weckwerth, T. M. (2014). RADAR IN ATMOSPHERIC SCIENCES AND RELATED RESEARCH : Current Systems, Emerging Technology, and Future Needs. Bulletin of the American Meteorological Society, 95(12), 1850–1861.
RADAR IN ATMOSPHERIC
SCIENCES AND RELATED
RESEARCH Current Systems,
Emerging Technology, and Future Needs
by Howard b. bluestein, robert M. rauber, donald w. burgess,
bruce albrecHt, scott M. ellis, yvette P. ricHardson, david P. Jorgensen,
stePHen J. Frasier, PHilliP cHilson, robert d. PalMer, sandra e. yuter,
wen-cHau lee, david c. dowell, Paul l. sMitH, Paul M. Markowski,
katJa FriedricH, and taMMy M. weckwertH
Emerging radar technologies best suited to
addressing key scientific questions and future
problems are identified and discussed.
T
o help its Lower Atmosphere Observing Facilities (LAOF)
program provide researchers with instrumentation and
platforms, the National Science Foundation (NSF) con-
vened a community workshop1 with the purpose of defining
the problems of the next generation that will require radar
technologies and to determine the suite of radars best suited
to solving these problems. The workshop addressed a subset
of the instruments2 mentioned by the National Research
Council (2009) as being or eventually becoming essential
operational facilities. Climate scientists have also recom-
mended similar reviews of instrumentation, in part because
“we may . . . need easily deployable short-term observational
technologies to monitor potential abrupt changes or impor-
tant regional trends” (National Research Council 2010).
Based on presentations and discussions at the NSF work-
shop (Figs. 1 and 2), we considered the following questions:
1 The workshop was held at the NCAR in Boulder, Colorado, from 27
to 29 November 2012. There were over 120 participants who repre-
sented six countries (United States including Hawaii, Canada, France,
Germany, Japan, and Taiwan) and three continents. Additional par-
ticipants attended by web conferencing. More information about the
workshop including presentations and posters may be found online
(at www.joss.ucar.edu/nsf_radar_wksp_nov12/).
2 Spaceborne radars, which would require collaboration among NASA,
NOAA, and NSF, were not considered during the workshop.
A rapid-scan, X-band, polarimetric, Doppler radar (RaXPol) probing a supercell
in southwestern Oklahoma on 23 May 2011. (Courtesy of H. Bluestein.)
http://www.joss.ucar.edu/nsf_radar_wksp_nov12/
1) What current radar technologies are considered
critical to answering the key current and emerging
scientific questions? What are the strengths and
weaknesses of those technologies as they are cur-
rently implemented?
2) What emerging radar technologies would be
most helpful in answering the key scientif ic
questions?
3) W hat gaps, if a ny, ex ist in rada r obser v ing
technologies? (A “gap” can mean the absence
of a critical technology or a lack of access by
the general research community to an existing
technology.)
While we address these questions
here, an online supplement (available
online at http://dx.doi.org/10.1175
/BAMS-D-13-00079.2) reviews in
more depth the radar technolog y
currently in use(see Tables 1–3 for
sur veys of current ground-based
mobile, airborne, and deployable
radars, respectively) and provides
more information about the work-
shop itself.
E M E R G I N GR E S E A R C H
FRONTIERS. Future research3
with radar will involve multiplat-
form, multimodel investigations.
There will be four major research
themes involving radar.
Extreme weather. Studies of tropical-
cyclone genesis including spatial
structure, rapid intensification, and
evolution during landfall, convective weather systems,
and winter weather systems will all require radar. It
was proposed that this should include a rapid-response
capability to facilitate study of extreme weather events
that are predictable days in advance.
Hydrology and water resources. Studies of tropical–
extratropical transition, f looding from landfalling
tropical systems, midlatitude convective systems,
atmospheric rivers, the interaction of weather systems
with orography and topography, weather modifica-
tion for precipitation enhancement, and mapping the
water vapor field for numerical weather prediction
3 This section is based on a presentation by Robert Rauber at the workshop.
Fig. 1. Small discussion group (from left to right: John Williams, Bob
Palmer, Jim Wilson, and Phil Chilson) during the radar analysis and
software session. (Courtesy of H. Bluestein.)
AFFILIATIONS: bluestein—School of Meteorology, University
of Oklahoma, Norman, Oklahoma; cHilson and PalMer—School
of Meteorology, and Advanced Radar Research Center, University
of Oklahoma, Norman, Oklahoma; rauber—University of Illinois
at Urbana–Champaign, Urbana, Illinois; burgess—Cooperative
Institute for Mesoscale Meteorological Studies, Norman, Oklahoma;
Jorgensen—National Oceanic and Atmospheric Administration/
National Severe Storms Laboratory, Norman, Oklahoma; albrecHt—
University of Miami, Miami, Florida; ellis, lee, and weckwertH—
National Center for Atmospheric Research, Boulder, Colorado;
ricHardson and Markowski—The Pennsylvania State University,
University Park, Pennsylvania; Frasier—Microwave Remote Sensing
Laboratory, University of Massachusetts Amherst, Amherst,
Massachusetts; yuter—North Carolina State University, Raleigh,
North Carolina; dowell—National Oceanic and Atmospheric
Administration/Earth System Research Laboratory, Boulder, Colo-
rado; sMitH—South Dakota School of Mines and Technology, Rapid
City, South Dakota; FriedricH—University of Colorado, Boulder,
Colorado
CORRESPONDING AUTHOR : Howard B. Bluestein, School of
Meteorology, University of Oklahoma, 120 David L. Boren Blvd.,
Suite 5900, Norman, OK 73072
E-mail: hblue@ou.edu
The abstract for this article can be found in this issue, following the table
of contents.
DOI:10.1175/BAMS-D-13-00079.1
A supplement to this article is available online (10.1175/BAMS-D-13-00079.2)
In final form 8 January 2014
©2014 American Meteorological Society
1852 DECEMBER 2014|
http://dx.doi.org/10.1175/BAMS-D-13-00079.2
http://dx.doi.org/10.1175/BAMS-D-13-00079.2
mailto:hblue%40ou.edu?subject=
http://dx.doi.org/10.1175/BAMS-D-13-00079.1
http://dx.doi.org/10.1175/BAMS-D-12-00243.2
and estimating precipitation rates will also all require
radar.
Global and regional climate and climate change.
Radar will be needed to study, for example, tropical
cloud systems, oceanic tropical convection and its
impact on climate, the effects of aerosols on cloud
microphysics, and global and regional orographic
precipitation as a source of water supply. Dr. Rauber
suggests that during the next two decades global
climate change impacts are likely to drive research
more and more.
I n t e g r a t i o no fr a d a rd a t aw i t h
numerical models. This particularly
applies to developing high-resolu-
tion regional and global models that
make use of assimilated radar data.
To address these scientific prob-
lems , rad a rs w i l l be needed on
diverse platforms including ships,
aircraft, and stationary and mobile
ground-based platforms. Some of
the latter platforms may be quasi
mobile: able to move the radar to
a f ixed location for an extended
period. Other radars will be perma-
nently installed at fixed locations
and may be part of a network of
either high-powered, widely spaced
r ad a rs or low-powered , closely
Fig. 2. Participants (Dave Jorgensen on the left; unidentified on the
right) checking lists of priorities posted on the walls (gallery walk)
during radar analysis and software session. (Courtesy of H. Bluestein.)
Table 1. Ground-based mobile radars survey.
Name Band Beamwidth Polarization Scan rate Owner
Shared Mobile Atmospheric Research
and Teaching Radar (SMART-R)
C 1.5°
1 dual,
1 single
33° s-1
University of Oklahoma (OU)/
Texas Tech
Seminole Hurricane Hunter C — single 10° s-1 Florida State University (FSU)
Doppler on Wheels (DOW) X 0.9° 2 dual 50° s-1
Center for Severe Weather
Research (CSWR)
NOAA X-band, dual-Polarized radar
(NOXP)
X 1° dual 30° s-1 NOAA
UMass dual-polarized X-band mobile
Doppler radar (X-Pol)
X 1.25° dual 20° s-1 UMass
Mobile Alabama X-Band (MAX) X 1° dual 18° s-1
University of Alabama in
Huntsville (UAH)
Texas Tech Ka-band (TTUKa) Ka 0.33° 2 single 20° s-1 Texas Tech
UMass W-band W 0.18° dual 5° s-1 UMass
Rapid DOW X 1° single 50° s-1 × 6 beams CSWR
Rapid-scanning, X-band, polarimetric
mobile radar (RaXPol)
X 1° dual 180° s-1 OU
Mobile Weather Radar, 2005 X-band,
Phased Array (MWR-05XP)
X 1.8° × 2° single
180° s-1
up to 55°
Naval Postgraduate School
(NPS) Center for Interdis-
ciplinary Remotely-Piloted
Aircraft Studies (CIRPAS)
UMass X-band phase-tilt array X 2° × 3.5° dual 90° s-1 UMass
AIR X 1° × 25° single 40° s-1 OU
PX-1000 X 1.9° dual 50° s-1 OU
1853DECEMBER 2014AMERICAN METEOROLOGICAL SOCIETY |
spaced radars. There will also be a diversity of scan-
ning strategies, ranging from traditional scanning
radars [for sur veillance, range–height indicator
(RHI), and sector scans] to rapid-scan radars and
vertically pointing profilers, as well as airborne scan
strategies and airborne profilers. There will also be
a need for diversity of wavelengths and polarization
configurations. Typical bands (wavelengths) used
range over the S (~10 cm), C (~5 cm), X (~3 cm),
Ka/Ku (~1 cm), and W (~3 mm) bands and will vary
according to the platform used. Radars will usually
const it ute just one component of mu lt isensor,
multiplatform, and multimodel investigations of
meteorological phenomena.
EMERGING TECHNOLOGIES. Emerging tech-
nologies in meteorological radar4 include solid-state
transmitters with pulse compression, polarimetric
phased-array radar, imaging radar (or “ubiquitous
radar”), and “adaptive collaborative” radar net-
works such as the Collaborative Adaptive Sensing
of the Atmosphere (CASA; McLaughlin et al. 2009).
Table 2. Airborne radars survey.
Radar
name Hurricane surveillance NOAA P-3 ELDORA
Wyoming Cloud Radar
(WCR)
Owner
NOAA [Environmental
Science Services
Administration (ESSA)]
NOAA NSF/NCAR University of Wyoming
Platform DC-6
P-3 Orion 4-engine
turboprop
Electra, NRL P-3 King-Air, C-130
Scanning RHI scan tied to drift angle
RHI–fore–aft ±20°
normal to heading
RHI–fore–aft ±20° normal
to heading
Vertical or horizontal
dual beam
Radar type Noncoherent Doppler Doppler Doppler, dual pol
Frequency X band X band X band W band
Years ~1964–75 1977–present 1992–2012 1995–present
Radar
name
ER-2 Doppler Radar
(EDOP)
Cloud Radar System
(CRS)
High-Altitude Imaging
Rain and Wind Profiler
(HIWRAP)
ER-2 X-band Radar
(EXRad)
Owner
National Aeronautics
and Space Administration
(NASA)
NASA NASA NASA
Platform ER-2 ER-2 WB-57, Global Hawk ER-2
Scanning
Dual beam
(fixed, nadir and +35°)
Nadir Nadir conical, dual beam
Dual beam: conical or
cross-track scan about nadir;
fixed nadir
Radar type Doppler, dual pol (LDR) Doppler, dual pol (LDR) Doppler Doppler
Frequency
(band)
X W K
u
, K
a
X
Years 1993–present 2002–present 2010–present 2010–present
4 Reviewed by R. Palmer at the workshop.
1854 DECEMBER 2014|
Future technologies include “digital at every element”
phased-array radar, passive radar, multimission
networks, ultra low-cost dense networks, and spec-
trum sharing.
Solid-state pulse-compression transmitters, which
are commercially available, make use of gallium
arsenic or gallium nitride technologies. They are
low cost, low weight, and low power (so they need
longer pulses to achieve high sensitivity) but enable
active phased-array and ultra low-cost radars, such as
those to be placed on airborne platforms or in large,
densely spaced networks. Challenges to their full
implementation include suppressing range sidelobe
effects and correcting for blind range (Cheong et al.
2013). For conventional pulsed radars, the range
resolution degrades as the pulse duration increases.
However, using frequency modulated waveforms the
range resolution is decoupled from pulse duration
and instead is inversely proportional to bandwidth.
Unfortunately, range sidelobe contamination and
blind range challenges (at close range) are introduced;
the nature of the nonlinear modulation must be
optimized to reduce the former. Short-pulse blind
range-filling techniques are available, but they create
Table 2. Continued.
Radar
name
Super Polarimetric
Ice-crystal Detection
and Explication Radar
(SPIDER)
Environmental Canada
Cloud Profiling Radar
(EC CPR)
Radar System Airborne
(RASTA)
National Research Council
(NRC) Airborne W and
X-band Polarimetric
Doppler Radar (NAWX)
Owner Japan Canada France Canada
Platform Gulfstream-II Convair-580 Falcon 20, ATR-42 Convair 580
Scanning -40° to +95° scan across
flight direction
Fixed zenith and nadir
looking
3 down beams, 2 up beams;
±15° sector
Vertical and side looking
Radar type Doppler, dual pol Noncoherent Doppler Doppler, dual pol
Frequency
(band)
W K
a
W X, W
Years 1998–present 1999–present 2000–present 2006–present
Radar
name
G-IV Tail Doppler
Radar
High-Performance
Instrumented
Airborne Platform
for Environmental
Research (HIAPER)
Cloud Radar (HCR)
Airborne Cloud Radar
(ACR)
Imaging Wind and Rain
Profiler (IWRAP)
Owner NOAA NSF NCAR NASA UMass
Platform NOAA G-IV NSF G-V NASA P-3, DC-8 NOAA P-3
Scanning RHI-Fore-Aft ±20°
normal to heading
RHI Nadir Conical scan about nadir, quad
beam (30°, 35°, 40°, and 50°)
Radar type Doppler Doppler, dual pol Doppler dual pol Doppler dual pol
Frequency
(band)
X W W C, K
u
Years 2010 2013–present 1995–present 2002–present
1855DECEMBER 2014AMERICAN METEOROLOGICAL SOCIETY |
an abrupt change in sensitivity at the transition from
short to long pulse. Aside from the commercially
available pulse compression systems, others are
mobile systems at Ka and X bands (Table 2).
T h em a i nc h a l l e n g e st oi n c l u d i n gd u a l –
polarimetric capabilities on phased-array antennas
are that horizontal–vertical orthogonality is not
preserved as the phased-array antenna is steered off
the principal planes and that the antenna gain and
beamwidth change for off-broadside pointing direc-
tions. Engineering development efforts are ongoing
at several places, including Massachusetts Institute
of Technology Lincoln Laboratories (MIT-LL) for an
S-band overlapped subarray, BCI/Lockheed Martin
for an S-band 12 × 12 element prototype, and the
National Center for Atmospheric Research (NCAR)
for a C-band airborne system. Meanwhile, actual
weather measurements have been made successfully
with an X-band phase tilt antenna from collaboration
between the University of Massachusetts (UMass)
and Raytheon (“phase-tilt radar”; Orzel et al. 2011)
and are planned at the University of Ok lahoma
(OU) for an S-band cylindrical antenna [Cylindrical
Polarimetric Phased Array Radar (CPPAR); Zhang
et al. 2011] for the National Severe Storms Laboratory
(NSSL) Multi-Function Phased Array Radar (MPAR)
program (Zrnić et al. 2007; Weber et al. 2007). The
solution to the polarization orthogonality problem
for both of these designs is to stay on the principal
planes while scanning. The former operates at X
band, steers electronically in azimuth and mechani-
cally in elevation, has a 2.5°–3.5° half-power beam-
width, is low powered, and makes use of nonlinear
frequency modulated pulse compression; the latter
operates at S band, is fully electronically steered
using commutating beams around the cylinder (but
is frequency steered in elevation for cost reduction),
is high powered, and has 4.5° half-power beamwidth.
An alternative to (analog) phased-array technolo-
gy for rapid scanning is the imaging-radar technique,
in which a relatively broad region is illuminated by
the transmitted beam. Digital beamforming (by
which the phase and amplitude of the signal received
at each antenna element are altered digitally at each
separate receiver for each antenna element, rather
than through separate phase delays for each element,
but with just one receiver for all antenna elements)
allows for simultaneous measurements with an infi-
nite number (not all independent) of receiving beams
each of a given half-power beamwidth: for example,
of 1°. The first radar to make use of this technique is
the Atmospheric Imaging Radar (AIR) at OU (Isom
et al. 2013), in which an elliptical transmitted beam,
narrow in azimuth but wide in elevation, illuminates
the volume. This radar operates at X band and pro-
duces instantaneous RHIs but is scanned mechani-
cally in azimuth. In the future, it will be possible to
scan both in elevation and in azimuth through the
imaging-radar technique using digital beamforming
in two dimensions, not just one. A major advantage
is that ground clutter is rejected via adaptive array
processing (e.g., spatial filtering). This type of clutter
filtering can also reject moving targets, such as air-
craft and wind turbines. To date, data from the AIR
have been processed by the Fourier method and the
robust Capon method, each of which has strengths
and weaknesses. So far the AIR has been used to
probe tornadoes.
The Toshiba Corporation has designed an X-
band phased-array radar system that makes use of
both an active phased-array antenna and digital
beamforming. The 1° half-power beamwidth antenna
Table 3. Deployable-radars survey.
Large systems Medium sized Small Zenith pointing
NCAR S-Pol ARM X/Ka University of Iowa X-Pol
ARM Ka-band zenith radar (KaZR)
[Millimeter Wave Cloud Radar
(MMCR)]
CSU–CHILL ARM Ka/W OU PX-1000 W-band ARM Cloud Radar (WACR)
NASA N-Pol NASA D3R (Ku/Ka)
CASA Integrated Project 1
(IP-1)
Earth System Research Laboratory
(ESRL) W band
UMass Advanced Multi-Frequency
Radar (AMFR) (Ku/Ka/W)
ESRL S band
ARM C band
MIT-LL C band
Long range:
precipitation, clear air
Short–long range: clouds,
precipitation
Short range: precipitation,
networks
Profiling: clouds, precipitation,
microphysics
1856 DECEMBER 2014|
scans mechanically in azimuth and electronically in
elevation. Low powered and making use of pulse com-
pression, it is installed at Osaka University in Japan.
While CASA is a concept in a networked radar
system that has been tested in the United States
(McLaughlin et al. 2009), in Japan there is another
closely spaced network of X-band, solid-state, low-
powered, lightweight radars called WITH, built
by Weathernews, Inc. These are retrofitted radars
having a half-power beamwidth of 6° and are highly
mobile (can be easily towed by a car, put on top of
buildings, etc.).
In the future, digital-at-every-element phased-
array antennas will become available. The real-time
computational load will be tremendous, but the
degrees of freedom for adaptive beamforming, etc.,
will be huge. An additional major challenge with such
radars will be calibration.
Also in the future, it may be possible for passive
radar networks to be set up using “transmitters of
opportunity” such as those from television stations,
FM radio stations, and cellular phone networks.
Examples of such networks include Bistatic Network
(BiNet) (Wurman et al. 1993; Friedrich and Hagen
20 04), using Weat her Sur vei l la nce Rada r-1988
Doppler (WSR-88D) radars, and the U.S. Department
of Defense Integrated Sensor Is the Structure (ISIS),
using FM radio transmitters.
Multimission radar networks that can be used
for aircraft surveillance, weather observations, and
communications may be built with the aim of savings
resulting from decreasing the overall number of
radars used. Ultra low-cost dense networks making
use of solid-state transmitters with pulse compression
may be implemented. However, the weather-radar
community will face competition from the wireless
communication industry, which wants to use some
of the weather-radar frequency bands. Some coopera-
tion and coordination of functions will be required.
Possible solutions include passive radar networks,
adaptive phased-array radar systems (which have
tremendous advantages for beam agility and coor-
dination, and interference suppression), and other
forms of multimission networks.
RECOMMENDATIONS. To address high-priority
research topics, specific radars on specific platforms
will be required. We summarize the community’s
opinion (as it emerged from workshop discussions)
of both the specific types of radars and the platforms
needed and also the opportunities for radar support of
high-priority research. The following findings and rec-
ommendations are not ordered according to priority.
Polarimetric radars are needed to study pre-
cipitation processes, including those associated with
f looding in general and f lash f looding specifically;
to study cloud processes, especially those associated
with mixed-phase clouds; and to study insect and
bird behavior and migration. Measurements are espe-
cially needed to characterize ice microphysics better,
perhaps also using polarization modes other than
orthogonal linear. Errors related to dual-polarization
technology need to be quantified better, particularly
in the simultaneous transmit/receive mode. There
should be movement toward quantif ying micro-
physical processes and hydrometeor distributions in
four dimensions. Hydrometeor classification could
be taken to a new level with new instrumentation
such as the A-10 aircraft (www.cirpas.org/a10spa
.html) and techniques such as dual-polarization and
multifrequency radar techniques, which are cur-
rently underutilized. Polarimetric radar observa-
tions could also be used for electrification research.
Researchers need to be made aware of the different
uses of WSR-88D data and, in particular, for the study
of ice microphysics, despite the difficulties in using
data when both the horizontal and vertical beams are
transmitted simultaneously. Real verification of dual-
polarization measurements on large scales is needed.
S-band, Bragg scattering radars are needed to
study chemical transport and also to study features
in clear air, such as upper-level fronts and jets,
low-level jets, and surface boundaries along which
convective initiation may occur. Currently CASA
radars (and in general low-cost radar networks) lack
clear-air data collection capabilities, since monos-
tatic X-band radars cannot detect Bragg scattering
in clear air. Operational refractivity measurements
from the WSR-88D radars need to be developed and
exploited so that mesoscale detail in the temperature
and moisture fields can be better resolved. The com-
munity would like to have access to mobile, S-band
radar systems with a 1° half-power beamwidth or
less. Soon a transportable (trailer towed) radar will
become available from the Naval Postgraduate School
(NPS) Center for Interdisciplinary Remotely-Piloted
Aircraft Studies (CIRPAS), but with lower spatial
resolution.
Airborne Electra Doppler Radar (ELDORA)-like
radars are needed to study convection and tropical
cyclogenesis over the ocean and convection over
land, especially in mountainous or remote areas
where ground-based radars cannot be easily deployed
(Hildebrand et al. 1994). The existing ELDORA has
not been requested much lately because it is difficult
to process its data and Naval Research Laboratory
1857DECEMBER 2014AMERICAN METEOROLOGICAL SOCIETY |
http://www.cirpas.org/a10spa.html
http://www.cirpas.org/a10spa.html
(NRL) support is also needed to f ly the P-3. It was
suggested that perhaps NSF-sponsored users could
piggyback on National Oceanic and Atmospheric
Administration (NOAA) experiments. As alternatives
to ELDORA, however, the NOAA P-3 radars are dif-
ficult to use and expensive and involve a complicated
process to obtain; use of them needs to be coordi-
nated with other NOAA experiments. Operations of
a NOAA P-3 and ELDORA would be less expensive if
they could be deployed for short periods of time (e.g.,
just a few days) rather than for long field campaigns
with long waiting periods. NSF needs to establish
a mechanism to funnel funds through NOAA so
the cost of using a NOAA P-3 falls. There was brief
discussion on how to speed up the replacement of
ELDORA, since the NOAA P-3 is not available for 6
months out of the year and is very expensive. There
is also a need for replacing ELDORA with multiple-
waveleng th, dua l-polarization capabilit y. W.-C.
Lee noted that EOL at NCAR has been evaluating
whether the Airborne Phased-Array Radar (APAR)
development (replacement for ELDORA) time can be
accelerated with more funding by making it possible
to perform some tasks simultaneously rather than
sequentially.
There should be support for a diversity of radar
platforms at several wavelengths. Estimates of snow,
ice, and cloud properties and the retrieval of cloud
water and water vapor fields will make use of more
multiple-wavelength radars, benefiting a wide range
of atmospheric studies. It is difficult to study cloud
and precipitation processes owing to their high spatial
and temporal variability, so improved resolution is
required. The range resolution might be sufficient,
but angular resolution depends on the antenna size
and the range from the radar; shorter-wavelength
radars might yield useful cross-range resolution while
maintaining antenna dish size. The use of multiple-
wavelength radars might solve help mitigate attenu-
ation problems at short wavelengths.
There already is a good mix of truck-mounted
mobile radars (including rapid-scan radars) at various
wavelengths (C, X, Ka/Ku, and W bands), which need
to be maintained. Multiple radars mounted on the
same platform are needed to study the microphysics
and dynamics of precipitation systems and convec-
tive storms. Improvements are needed in instru-
ment integration, so that combined measurements
of kinematics, thermodynamics, and microphysics
at fine spatial and temporal resolution can be made.
Multiple-wavelength airborne radars are also needed.
A very high-frequency (VHF) profiling system
with Bragg scattering capabilities for boundar y
layer applications might be developed and included
in the deployment pool for making temperature
and moisture observations; this capability could
include three dimensions if a network is developed.
Since mov ing many prof ilers is ver y expensive,
perhaps a network of deployable profilers could be
developed. Wind and thermodynamic observations
above the planetary boundary layer are also needed;
such prof ilers should be developed. Thermody-
namic profiling radars are required also for study-
ing mesoscale features in phenomena such as winter
storms and for studying convective initiation. Cloud
(high frequency) radars are needed to study cloud and
precipitation microphysics associated with convec-
tive storms, tropical convection, winter storms, and
orographic precipitation.
There is a need to have the capability to make radar
observations in data-sparse regions, such as near the
poles, over the oceans, and in mountainous areas; to
do so, we need, in addition to airborne radars such as
ELDORA, ship-based radars and perhaps buoy-borne
radars as well. Such radar observations are important
for climate research related to tropical convection and
polar clouds (e.g., for ice microphysics studies). The
concepts of how to move facilities to remote areas
should be improved. We need to consider if existing
radars can operate in the harsh conditions of remote
regions. If not, we need to upgrade the technology.
These radars should be inexpensive and be capable of
operating unattended for long periods of time and of
calibrating themselves. Standards for calibration and
providing information on the calibration process for
each radar platform will be needed.
Some deployable networks of radars and other
instruments are needed for rapid-deployment situ-
ations. Such mobile networks of radars are valuable
facilities that need to be maintained rather than
developed. We need gap-filling radars with easier
deployment capabilities to complement larger radar
systems in, for exa mple, mountainous regions.
Networks in urban areas are also needed to study
and monitor air pollution processes, particularly, as
noted earlier, in clear air. These networks need im-
provements in their adaptive scanning strategies to
improve trade-offs between operational surveillance
and scientific-research functions.
Emerging phased-array technology, which can
improve temporal resolution without reducing data
quality, would help answer the key scientific questions
related to cumulus convection, convective storms, and
boundary layer processes. CASA-type radar networks
should be upgraded to make use of phased-array
technology.
1858 DECEMBER 2014|
We need better software tools for radar display
and analysis. In particular there should be unified
radar data archiving (which already exists for large
field experiments), open-access data, better coordi-
nation of radar data from the various platforms, and
improvements in radar data formats, software, and
analysis tools (Table 4). We also need the standard-
ization of software packages and toolkits (e.g., open-
source algorithms were recommended so that results
can be reproduced by other groups), unification of
data sharing policies with good documentation, the
ability to retrieve information quickly and easily and
accessible to everyone, and the integration of diverse
datasets. More observational datasets are necessary to
verify algorithms and techniques. The Atmospheric
Radiation Measurement Program (ARM) and NCAR
currently are collaborating to improve radar soft-
ware capabilities and “Cf Radial” will soon replace
the Doppler Radar Data Exchange (DORADE) and
Universal Formats. The community strongly supports
the NCAR-led software development efforts. We also
need to provide better products (e.g., precipitation
and cloud characteristics) for the modeling commu-
nity. It was recommended that we need verification
of research radar data from WSR-88D radars.
There are a number of ways to enhance availability
of radar instrumentation for the community. We
need the capability for fast-response, multiagency,
multiplatform experiments. In particular, we need
the ability to mobilize ground-based and airborne
rada rs (a nd ot her i nst r u ments) for potent ia l ly
historic targets of opportunity. It should be easier
to access nondeploy ment pool instruments and
coordinate multi-institutional access to facilities.
There is a website (http://faesr.ucar.edu) to help
investigators locate radar instruments t hat are
not necessarily part of the deployment pool. It is
up to the community to keep this online resource
updated with new instrumentation and facilities.
We need easier and faster facility access for proof-
of-concept experiments, including opportunities
for more 20-h-type projects [e.g., those available
through Colorado State University–University of
Chicago–Illinois State Water Survey (CSU–CHILL)]
requesting NSF radar facilities. Some feel there is
insufficient understanding of different frequency
capabilities (e.g., S band versus other bands: e.g., W
band, X band, etc.) versus mobile (primarily X- and
C-band radars) and deployable (i.e., movable radars
primarily operate at S band) systems. Also, there
Table 4. Radar software needs based on combined responses from workshop participants and an online
survey of members of the radar community who were unable to attend the workshop. Similar topics
among workshop group responses were consolidated. Scores are the number of votes for each topic.
Topic
Personal
research
needs
Community
needs
Total
score
NCAR maintained centralized repository for radar software (esp. including wind
synthesis) with datasets for sw testing
55 41 96
Standardized software packages and toolkits (multiplatform, modular, menu driven, easy
for community to add to, ease of conversion among new and old radar data formats)
30 53 83
Training (workshops/online tutorials) 48 15 63
Ability to integrate radar and nonradar datasets 25 32 57
Open-source tools and software 30 16 46
3D/4D visualization software (with publication quality output) 24 21 45
Next generation wind synthesis software (REORDER/CEDRIC) maintaining current
functionality and including new techniques
15 27 42
Common radar data format standard and a common metadata standard 19 15 34
64-bit compatible real-time display software tool 19 11 30
Improved radar data editing (Solo) and documentation 12 20 32
Automated quality control software 14 13 27
Detailed documentation for data products, tools, and code 18 7 25
Improved dual-polarization processing 10 12 22
Accessible variational Doppler radar assimilation and thermodynamic retrieval 7 4 11
326 287 613
1859DECEMBER 2014AMERICAN METEOROLOGICAL SOCIETY |
http://faesr.ucar.edu
should be more opportunities for access of phased-
array radars for the NSF community.
Educationa l suppor t for larger communities
such as undergraduate students could be improved,
with more educational outreach and student par-
ticipation in field campaigns and the inclusion of
students in the data analysis process. Complicated
microphysical concepts should be taught using NSF
radar facilities.
There are several other issues concerning future
radar development. Things that we cannot do now
but will be able to do with a projected increase in
the availability of computer resources include the
following: adaptive signal processing and beam form-
ing algorithms, which will improve angular resolu-
tion and data quality; integrating data from all radars
into a network; recording the full Doppler spectrum
routinely for all radars and reducing the cost for
archiving data; allowing for full data streaming in
real time and improvements in data visualization; and
real-time data processing including quality control,
vector analysis, merging of datasets, and communi-
cating large amounts of data.
Bot h universities and NCAR shou ld develop
instrumentation, perhaps with universities educating
students on instrument development while NCAR
develops instruments that
can be used directly more
quickly; in addition, uni-
versities should focus more
on unique or more novel
instruments. The process
of instrument development
shou ld be col laborat ive.
NCAR already has visiting
programs for undergradu-
ate engineering students
[Summer Undergraduate
P ro g r a mforE n g i ne e r-
i n gR e s e a r c h(S U PE R)
and Technical Internship
Program (TIP)], and they
should be utilized more.
The public could get more
involved in some of our
act iv it ies a nd more stu-
dents could be involved by
making data and research
products available to a larg-
er community, as is done
now, for example, with the
CHILL radar.
The radar community
is relatively small and the
number of users of radars
needs to grow by including
people from other disci-
plines such as chemistry,
m o d e l i n g ,a ndbi o l o g y
and by advocating cross-
cutting research projects
to a larger community (e.g.,
hydrology, climate studies,
and engineering). There
should be a focus of broad
instrument applications,
NOTES ON TERMINOLOGY: SOME SPECIALIZED TERMS
USED IN THIS ESSAY.
Pulse compression: The use of special forms of pulse modulation (amplitude or
frequency or phase) to permit a radar system to achieve higher range resolution
than normally permitted by a given pulse duration. The advantage of pulse com-
pression over simply transmitting shorter pulses is that high range resolution is
achieved while maintaining the benefits of high average power. (This is a shortened
and slightly edited version of the entry in the AMS Glossary of Meteorology, available
online at http://glossary.ametsoc.org/wiki/Main_Page.)
Imaging radar: A radar that uses a relatively wide-beamwidth antenna for
transmitting and numerous independent antennas for receiving. The signals from
the antennas for receiving are used together to implement digital beamforming to
achieve narrow beams in selected directions, which provide simultaneous angular
sampling within the volume of the transmitted beam. The imaging radar there-
fore essentially takes an instantaneous snapshot of the atmosphere within the
transmitted beam, thereby providing excellent temporal resolution.
Range sidelobe compression: Pulse compression receivers employ a
correlation operation on the transmitted waveform. All practical waveforms have
correlation functions that spread some energy away from the desired range into
“range sidelobes.” In many respects, range sidelobes can be thought of as antenna
sidelobes but for the range direction rather than the azimuthal or elevation angle
directions.
Nonlinear modulation: Conventional pulse compression waveforms use a linear
change in frequency with time over the duration of the pulse, which is called linear
frequency modulation. Nonlinear frequency modulation uses a nonlinear variation
in frequency over the pulse duration. If designed properly, nonlinear frequency
modulation can have several advantages, such as a significant reduction in range
sidelobes.
Blind range: Pulse compression makes use of a longer pulse in order to increase
the sensitivity of the radar. The radar, however, cannot receive signals while this
long pulse is being transmitted. The range corresponding to the length of the long
pulse and shorter ranges are therefore not observed and called the blind range.
This blind range is mitigated by transmitting a short “fill pulse” along with the long
pulse.
Frequency steering: By changing the frequency of the transmitted signal, the
wavelength is changed. For fixed element spacing, a change in wavelength cor-
responds to a change in phase, which is how beam steering can be accomplished.
Frequency steering is a simple way of steering electronically, but it requires more
bandwidth and is therefore not a viable operational solution.
1860 DECEMBER 2014|
http://glossary.ametsoc.org/wiki/Main_Page
such as for forecasting, climate modeling, and cli-
mate studies.
Finally, radar developers need to have the vision
to think far ahead (~50 years). What might be useful
now might quickly become old technology.
ACKNOWLEDGMENTS. This paper and the work-
shop it summarizes were both supported by the Division
of Atmospheric and Geospace Sciences (AGS) of t he
National Science Foundation. The NCAR University Cor-
poration for Atmospheric Research (UCAR) Joint Office
for Science Support (JOSS) is acknowledged for hosting
the workshop and Brian Jackson at JOSS is acknowledged
for his support. Linnea Avallone was the NSF liaison; Jim
Huning provided the initial guidance for this workshop;
Steve Nelson, Brad Smull, and other AGS and Office of
Polar Programs (OPP) program officers also provided
support.
REFERENCES
Cheong, B. L ., R . Kel ley, R . D. Pa lmer, Y. Zha ng,
M. Year y, and T.-Y. Yu, 2013: PX-1000: A solid-
st ate pola r i me t r ic X-ba nd we at her r ad a r a nd
time–frequency multiplexed waveform for blind
range mitigation. IEEE Trans. Instrum. Meas., 62,
3064–3072.
Friedrich, K., and M. Hagen, 2004: Evaluation of
wind vectors measured by a bistatic Doppler
radar network. J. Atmos. Oceanic Technol., 21,
1840–1854, doi:10.1175/JTECH-1679.1.
Hildebrand, P. H., C. A. Walther, C. L. Frush,
J. Testud, and F. Baudin, 1994: The ELDORA/
ASTRAIA airborne Doppler weather radar:
Goals, design, and first field tests. Proc. IEEE,
82, 1873–1890, doi:10.1109/5.338076.
I nc e , T., S . J. Fr a sie r, A . Mu s c h i n s k i, a nd
A. L. Pazmany, 2003: An S-band frequency-
modulated continuous-wave boundary layer
profiler: Description and initial results. Radio
Sci., 38, 1072, doi:10.1029/2002RS002753.
Isom, B., and Coauthors, 2013: The Atmospheric
I m a g i n gR a d a r :S i m u l t a n e o u sv o l u –
me t r ic obs er v at ion s u si ng a pha s e d a r-
r a yw e a t h e rr a d a r.J .A t m o s .O c e a n i c
Technol., 30, 655–675, doi:10.1175/JTECH
-D-12-00063.1.
McLaughlin, D., and Coauthors, 2009: Short-
wavelength technology and the potential for
distributed networks of small radar systems.
Bull . Ame r. Meteor. Soc ., 90, 1797–1817,
doi:10.1175/2009BAMS2507.1.
National Research Council, 2009: Observing Weather
and Climate from the Ground Up: A Nationwide Net-
work of Networks. National Academies Press, 250 pp.
—, 2010: Advancing the Science of Climate Change.
National Academies Press, 528 pp.
Orzel, K., and Coauthors, 2011: Mobile X-band dual-
polarization phased array radar: System requirements
and development. 35th Conf. on Radar Meteorology,
Pittsburgh, PA, Amer. Meteor. Soc., 14A.4.
Weber, M. E., J. Y. N. Cho, J. S. Herd, J. M. Flavin, W. E.
Benner, and G. S. Torok, 2007: The next-generation
mu ltimission U.S. sur vei l la nce radar net work .
Bull. Amer. Meteor. Soc., 88, 1739–1751, doi:10.1175
/BAMS-88-11-1739.
Wurman, J., S. Heckman, and D. Boccippio, 1993: A bi-
static multiple-Doppler network. J. Appl. Meteor., 32,
1802–1814, doi:10.1175/1520-0450(1993)0322.0.CO;2.
Zhang, G., R. J. Doviak, D. S. Zrnić, R. Palmer, L. Lei,
and Y. Al-Rashid, 2011: Polarimetric phased array
radar for weather measurement: A planar or cylin-
drical configuration? J. Atmos. Oceanic Technol., 28,
63–73, doi:10.1175/2010JTECHA1470.1.
Zrnić, D. S., and Coauthors, 2007: Agile-beam phased array
radar for weather observations. Bull. Amer. Meteor.
Soc., 88, 1753–1766, doi:10.1175/BAMS-88-11-1753.
1861DECEMBER 2014AMERICAN METEOROLOGICAL SOCIETY |
http://dx.doi.org/10.1175/JTECH-1679.1
http://dx.doi.org/10.1109/5.338076
http://dx.doi.org/10.1029/2002RS002753
http://dx.doi.org/10.1175/JTECH-D-12-00063.1
http://dx.doi.org/10.1175/JTECH-D-12-00063.1
http://dx.doi.org/10.1175/2009BAMS2507.1
http://dx.doi.org/10.1175/BAMS-88-11-1739
http://dx.doi.org/10.1175/BAMS-88-11-1739
http://dx.doi.org/10.1175/1520-0450(1993)0322.0.CO;2
http://dx.doi.org/10.1175/2010JTECHA1470.1
http://dx.doi.org/10.1175/BAMS-88-11-1753
Copyright of Bulletin of the American Meteorological Society is the property of American
Meteorological Society and its content may not be copied or emailed to multiple sites or
posted to a listserv without the copyright holder’s express written permission. However, users
may print, download, or email articles for individual use.

Place your order
(550 words)

Approximate price: $22

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
$26
The price is based on these factors:
Academic level
Number of pages
Urgency
Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

Read more

Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

Read more

Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

Read more

Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

Read more