Phased Array R

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Phased Array RD at NSSL

• Phased Array Weather Radar Project
• Joint Action Group
• December 7, 2004

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Topic Outline

• Impact of NEXRAD
• PAR Status
• NOAAs Partners
• Congressional Study
• Early Tests
• Vision
• Summary

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NEXRAD Impact on Performance Measures

NEXRAD
Source NWS Office of Science and Technology
4
NEXRAD Impact on Society

• NEXRAD deployment reduced expected tornado
  fatalities by 45.
• NEXRAD deployment reduced expected tornado
  injuries by 40.
• Using EPA methods, this translates to a 378M
  benefit per year (8 years, FY03 dollars, deaths
  avoided only).
• (Sutter and
  Simmons, 2005)

5
PAR Status

• Navy accepts PAR from Lockheed Martin (Oct.
  2003).
• NSSL assigned to keep PAR in good working order
  as per NOAA/FAA/Navy MOU (Oct. 2003).
• Test and evaluation period underway (Oct. 2003
  present).
• NOAA funding for PAR (1M, FY04 2M, FY05).
• Working problems with digital signal processor,
  cooling system, and software (2004).
• PAR now ready to collect data and perform
  intercomparison and multi purpose use studies
  (January 2005 on).
• NOAA/FAA/NAVY calls for making PAR available to
  other agencies and research community by Dec.
  2006.

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NOAAs Partners in PAR

• Navy own SPY-1 antenna
• FAA investigating multi purpose use
• U of Okla. own environmental processor
• CASA UMASS, OU, CSU, U. of Puerto Rico
• National Weather Service (NOAA NWS)
• Lockheed Martin, BCI

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Interpretation of the Aerospace Inc. Study

• The Aerospace Inc. study indicates that phased
  array transmit/receive (T/R) elements will enjoy
  significant cost reductions over present prices.
• Companies interviewed in the Aerospace study
  pegged 2010 costs for active, T/R elements to be
  in the 35-250 range.
• The SPY-1 antenna, containing 5,000 individual
  passive elements at 1,500-2,000 each, cost
  10M.
• Thus it will be possible to manufacture a phased
  array antenna for weather surveillance for less
  than 1M. Note that this antenna includes the
  transmitter and primary receiver (active T/R
  elements).

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Early Tests - Reflectivity
PAR 20040530 012309Z 0.75deg
KTLX 20040530 012310Z 0.5deg
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Early Tests - Velocity (aliased)
PAR 20040530 012309Z 0.75deg
KTLX 20040530 012327Z 0.5deg
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Vision

• From Aerospace, Inc. Study
• Multi Purpose Radar
• Integrated Radar Network including CASA radars
• Using Radar Data to Initialize Forecast Models

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Vision from Aerospace, Inc. Study

• Given this price breakthrough, it is now
  possible to envision a four-faced radar system
  (four antennae mounted as in a pyramid) that
  would yield a weather radar with no moving parts.
  This would greatly reduce lifecycle cost and
  yield a volume scanning rate of approximately 20
  seconds. The current NEXRAD volume scanning
  rates are between 5 and 6 minutes.

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Multi Purpose Vision
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Integrated Radar Network Vision

• Deployment of scalable radar systems
• Local, regional, national accessible databases
• Heavy involvement of state and local governments
• Potential commercial involvement
• Media involvement

Big (NOAA, FAA), little (CASA) radars, other
(HLS, DOT,?) radars, built real-time accessible
data bases.
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Using Radar Data to Initialize Forecast Models

• Radar is the only technology that measures the
  atmosphere on the space and time scales of the
  phenomena one wants to forecast.
• Assimilation of radar data can retrieve wind,
  temperature, and pressure observations.

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Using Radar Data to Initialize Forecast Models (2)
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Using Radar Data to Initialize Forecast Models (3)

• Run very short term, very high resolution,
  ensemble based forecast models to get
  probabilistic forecasts of severe weather events.
• Move from warn on detection to warn on
  forecast.
• Extend tornado lead times from 12 minutes to 45
  minutes.

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Using Radar Data to Initialize Forecast Models (4)

• WFUS54 KOUN 032330
• TOROKC
• OKC151-040000-
• BULLETIN - EAS ACTIVATION REQUESTED
• TORNADO WARNING
• NATIONAL WEATHER SERVICE NORMAN OK
• 630 PM CDT THU OCT 3 2002
• THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED
  A
• TORNADO WARNING FOR...
• WOODS COUNTY IN NORTHWEST OKLAHOMA
• UNTIL 700 PM CDT
• AT 630 PM CDT...DOPPLER RADAR DETECTED A SEVERE
  THUNDERSTORM
• CAPABLE OF PRODUCING A TORNADO 13 MILES WEST OF
  CAPRON...MOVING
• EAST-NORTHEAST AT 30 MPH.

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Summary

• PAR technology will become cheap.
• Multi-purpose radars are feasible
• Weather surveillance
• Radar data assimilation into very high
  resolution, very short term, ensemble based
  forecast models
• Aircraft tracking
• Non-cooperative aircraft tracking
• 4D measurements for dispersion winds
• Chem/bio detection
• Polarization diversity, multi-frequency, active
  PAR T/R elements already exist.
• Can government agencies collaborate on a
  multi-purpose project of this magnitude?

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Back Up Slides
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PAR Congressionally Mandated Study

• The October 2003 version of the Omnibus
  Appropriations Bill specifies, "A parallel
  assessment of the practicality of commercializing
  the SPY-1 or successor for weather forecasting is
  funded under the National Weather ServiceNWS
  shall submit a feasibility study to the
  Committees on Appropriations no later than May 1
  2004."
• The Aerospace Corporation produced an 89-page
  document as a result of a two-month, quick-look
  study effort that addresses these Congressional
  concerns.

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Results of the Aerospace Inc. Study

• One company stated that the cost of PAR
  transmit/receive elements will go from 1,200 in
  1999 to 250 in 2010 another company informally
  estimated the 2010 cost at 100. The Aerospace
  Corporation thinks that the cost will be closer
  to 35, but this estimate needs additional
  substantiation.
• Market evidence and engineering statistics
  indicate significant increases to component
  reliability, which will greatly reduce the impact
  of single-point-of failure components and result
  in much lower recurring costs.
• Integration of PAR technology into the existing
  NEXRAD system could be done gracefully.
• A formal, in-depth analysis is required to
  provide a clear picture of the cost/benefits of
  Phased Array Radar for weather Doppler radar
  application.
• A more comprehensive, top-down study should be
  undertaken to define architectural requirements
  and performance objectives that can be addressed
  by PAR in the 2005-2020 timeframe.
• This comprehensive study needs to be done in
  concert with the NSSL to quantitatively identify
  the performance benefits of PAR in terms of
  severe weather detection and potential savings in
  life and property.