Phased Array Radar

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Rapid Sampling of Severe Storms with the
National Weather Radar Testbed
Phased Array Radar
PAR
PAR
KTLX
KTLX
Pam Heinselman
Doug Forsyth, David Priegnitz,
Kevin Manross, Travis Smith, Rick Adams, Rick
Hluchan
OU Seminar Series 2 October 2007


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Acknowledgements
Mark Benner, Mike Schmidt, Richard Wahkinney,
Kurt Hondl, Allen Zahrai, Dick Doviak
Bob Staples, Chris Curtis, Sebastian Torres, John
Thompson, Dan Suppes
Bob Palmer, Mark Yeary, Tian-You Yu, Guifu Zhang
Mark Campbell, Wayne Sabin, Jorge Pica, Peter
Bronecke
Bob Blasewitz, Tim Maese
Mike Foster, David Andra, Steve Nelson, David
Sharp, Dan Miller
Ed Mahoney, Mike Magsig, Liz Quoetone, Jim
LaDue, Jami Boettcher, Andy Wood
WDTB
3
Partners
James Kimpel Dusan Zrnic
Ron Ferek
Tom McNellis
Richard Vogt
Jerry Crain Alan Shapiro
William Benner
John Heimmer
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Purpose of NWRT PAR
Prototype and Evaluate
What are the benefits and challenges of using a
Phased Array Antenna for meteorological
surveillance?
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National Facility

• Established as part of the MOU between NOAA,
  Navy, FAA and OU.
• Application windows
• Fall/Winter (Oct Mar) Deadline Aug 15th,
  Decision End of Aug
• Spring/Summer (Apr Sep) Deadline Feb 15th,
  Decision End of Feb
• Web Site www.nssl.noaa.gov/research/radar/nwrt_u
  se.php
• NWRT Assessment Panel
• Evaluate and regulate use of NWRT
• Members
• Ron Ferek Scott Sandgathe (Navy)
• Jim Williams Bill Benner (FAA)
• Mark Yeary Bob Palmer (OU)
• Jeff Kimpel Doug Forsyth (NOAA)

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NWRT ? MPAR
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National Symposium on
Multifunction Phased Array Radar
National Symposium on MPAR

• October 10-12, 2007
• National Weather Center, Norman, OK
• Theme
• Leveraging technology for Next-Generation
  National Radar System
• Registration opens 15 August 2007
• http//www.ofcm.gov/mpar-symposium/index.htm

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Phased Array Antennas perform stationary
electronic scanning

• Parabolic Antenna (WSR-88D)
• 1 feedhorn

• Phased Array Antenna (NWRT)
• 4,352
  transmit/receive
  elements

• Electronically steered

• Mechanically steered

• Stationary phased array

• Rotating reflector array

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Phased Array Antennas perform stationary
electronic scanning
Boresight Beam Axis
Axis
Radiating in Phase
Courtesy of Andrew Pazmany
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NWRT PAR is a Passive Array

• Passive Electronically Scanned Arrays
• Single RF source
• Power divided into phase shift modules

WSR-88D Transmitter
Courtesy of Andrew Pazmany
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Advantage of NWRT Phased Array Radar Faster Scan
Rates
Ultimate Goal
What we have now
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Advantage of NWRT Phased Array Radar Adaptable
Scan Capability
Radar Control Interface with VCP selector open
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Phased Array Radar WSR-88D
Similarities
PAR 9.4 cm WSR-88D 10 cm
Wavelength
VCPs

• PAR can mimic
• WSR-88D VCPs
• Nyquist frequency

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Phased Array Radar WSR-88D
Differences
1-min Scan Rate
Polarization
90?
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Phased Array Radar WSR-88D
Differences
Phased Array Radar
KTLX WSR-88D
Sampling
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Phased Array Radar WSR-88D
Differences
Phased Array Radar

• Sidelobes
• Second trip echo

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2007 Research Projects

• Radar Comparisons
• Algorithm work
• Aircraft Tracking
• Inferometry
• Oversampling and Whitening
• Lidar, X-band comparisons

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Earlier detection of large hail aloft
223346 UTC
15 August 2006
PAR Reflectivity cross-section, cappi (10 km),
and 0.5? PPI 31 elevation scans up
to 41?, 831 ?s PRT 90? sector
Images 26 s
Approximated WSR-88D Reflectivity cross-section,
cappi (10 km), and 0.5? PPI Images 5 min
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Earlier detection of microburst
223346 UTC
10 July 2006
PAR
PAR VCP 12 BMX 90? sector
Images 34 s
KTLX
WSR-88D VCP 12
Images 4.1 min
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Radial Divergence profile (T -13 min)
Storm-top divergence
Weak echo region
Updraft
Convergence at cloud base
Vertical
0.5 tilt
Vertical
0.5 tilt
PAR Divergence
PAR Reflectivity
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Radial Divergence profile (T -6 min)
Deep mid-altitude convergence
Weak outflow
Vertical
0.5 tilt
Vertical
0.5 tilt
PAR Divergence
PAR Reflectivity
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Radial Divergence profile (T 0 min)
Strong outflow
precipitation foot
Vertical
0.5 tilt
Vertical
0.5 tilt
PAR Divergence
PAR Reflectivity
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PAR vs TDWR
223346 UTC
10 July 2006
PAR
PAR VCP 12 BMX 90? sector
Images 34 s
TDWR Images 60 s
TDWR
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PAR vs TDWR
PAR Radial Velocity
TDWR Radial Velocity
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PAR vs TDWR
PAR Radial Velocity
TDWR Radial Velocity
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Earlier confirmation of intensifying/contracting
gust front
223346 UTC
PAR 010004 UTC
PAR 010004 UTC
Radar Location
Radar Location
Forward Flank Divergence
Inflow into Forward Flank
Forward Flank
Inflow Notch
Convergence
Weak Rotation
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Earlier confirmation of intensifying/contracting
gust front
223346 UTC
24 April 2006
PAR
PAR
PAR VCP 12 clone 90? sector
Images 58 s
KTLX
KTLX
WSR-88D VCP 12
Images 4.1 min
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Earlier confirmation of
reintensifying supercell
223346 UTC
Max vorticity gt .0075 s-1
g) KTLX 005945 UTC
8.20 km
6.64 km
5.25 km
2.15 km
1.20 km
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More coherent circulations
PAR
PAR
9 May 2007
PAR VCP 12 clone
45? sector Images 30 s
KTLX
KTLX
WSR-88D VCP 12
Images 4.1 min
30

Earlier detection of
tornadic vortex signature
PAR
PAR
Union City, OK Tornado (5/9/07)
PAR VCP 12 clone
45? sector Images 30 s
KTLX
KTLX
WSR-88D VCP 12
Images 4.1 min
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Tropical Storm Erin
TVS near Norge, OK
PAR
PAR
19 August 2007
PAR VCP 12 BMX 60?
sector 0.5? oversampling in azimuth Images 43 s
KTLX
KTLX
WSR-88D VCP 12
Images 4.1 min
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Tropical Storm Erin Eyewall
PAR
PAR
19 August 2007
PAR VCP 12 BMX 60?
sector 0.5? oversampling in azimuth Images 43 s
KTLX
KTLX
WSR-88D VCP 12
Images 4.1 min
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PAR Benefits Challenges
PAR Demonstration

• Benefits

• Challenges

• Allows focus on high-impact events
• More timely data interpretation
  decision-making
• Improved confidence in feature location,
  intensity, and evolution
• Potential to improve algorithm performance

• Choosing sector location
• Cognitive overload
• Understanding small-scale transient phenomena
  that are not observed regularly in WSR-88D data
• Radar hardware and display software limitations

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NWRT PAR Societal Impacts

• Societal Impacts

• Higher probability of detection
• Fewer false alarms higher public confidence
  (particularly on low-end severe events)
• Increased warning lead time
• More regionally specific warnings (location,
  intensity, timing)
• More timely in-flight information about storms
  that will improve aviation safety

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Six Planned Hardware, Software, and Engineering
Upgrades

• New Improved Matrix PC
• Dual 3 GHZ processors
• 10 gigabyte/sec ethernet backbone
• Build Dual Polarized Sub-array

• Modify Real Time Controller to Support Adaptive
  Scanning
• Improve display decision making for fast scan
  data

Activate Monopulse Ports
Implement uninterruptible Power Source for
NWRT
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ROADMAP
http//www.nssl.noaa.gov/project/pardemo
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