CASA Collaborative Adaptive Sensing of the Atmosphere NWRTPAR National Weather Radar Testbed Phased

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CASA Collaborative Adaptive Sensing of the
AtmosphereNWRT/PAR National Weather Radar
Testbed / Phased Array Radar

• Kurt D. Hondl
• DOC/NOAA/OAR
• National Severe Storms Laboratory

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CASA
Earths curvature prevents 72 of the atmosphere
below 1 km from being observed
WSR-88D
CASA X-Band
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CASA

• What is CASA?
• Collaborative Adaptive Sensing of the Atmosphere
• NSF sponsored Engineering Research Center
• University of Massachusetts (Amherst)
• University of Oklahoma
• Colorado State University
• University of Puerto Rico Mayaguez
• To revolutionize the way we observe, understand,
  and predict hazardous weather by creating
  Distributed Collaborative Adaptive Sensing
  networks that sample the atmosphere where and
  when end-user needs are greatest.

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CASA

• What is DCAS?

• Distributive concept a network of radars with
  overlapping beam coverage
• Collaborative multiple radar nodes communicating
  with one another
• Adaptive ability to adapt to features being
  observed and end-user needs
• Sensing radars designed using state-of-the-art
  solid-state, phased-array technology

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CASA

• Some things to know
• Demonstrate capability to scan below WSR-88D
• Scan below 3km
• SOCC System Operations Control Center
• Acquires data from all nodes
• MCC - Meteorological Command and Control
• Resource allocation based on competing user needs
  and weather threat(s) present
• Detection algorithms to identify severe weather
  features
• Sends scan strategy commands to radars

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CASA
Goal Map winds, rain below 3
km. Neighbor radars map cone of
silence above a radar. Multiple-Doppler wind
measurement throughout.
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CASA

• Initial Capability for IP1 (Oklahoma testbed)
• 4 Mechanical scanning radars (1 prototype exists)
• X-Band (3 cm wavelength)
• Antenna diameter of 4 feet (2 degree beamwidth)
• Dual polarization
• Dual PRF processing (effective Nyquist of 36 m
  s-1)
• Data collection rate of 24 radials per second
• Deployment spring of 2006
• 4 production radars to be built this year
• Moment data transmitted to SOCC via OneNet
• Detection algorithms developed in WDSS-II
• Focusing on severe convective events
• Circulation / Tornadic vortex signatures

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CASA Prototype Radar
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CASA Oklahoma Testbed
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CASA QPE Research

• IP2 Objectives (Rain Urban Flooding)
• Investigate QPE (Houston testbed)
• Collaboration with Texas Medical Center
• Covering watershed for Brays Bayou
• Site-specific forecasts at scales 10-100 km2
• Deployment 2007
• QPE impacts
• Fine scale temporal and spatial resolution
• Dual polarization parameters
• Attenuation at X-Band
• Designed for distributed hydrologic modeling as
  end user

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CASA

• Radar Engineering Research
• Electronic scanning arrays
• Technologies being investigated
• Frequency/Phase Array
• Phase/Phase Array
• Discrete Lens Array
• Issues
• Cost
• Technology development
• Dual polarization capability

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NWRT / PAR
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NWRT / PAR

• Objectives

• To demonstrate the effectiveness of a phased
  array radar in providing longer lead time for
  severe storm warnings.
• To provide a research testbed leading to the
  development of improved/new weather radars for
  the 21st century
• To support meteorological research into the
  evolution of hazardous weather events resulting
  in an enhanced capability to detect and predict
  severe weather
• To provide rapid update data for initialization
  of numerical models that will improve forecasting
  and nowcasting capability.
• To provide a platform for investigating
  feasibility of dual-use applications from a
  single radar ( I.e. weather, aircraft tracking,
  etc.)

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NWRT / PAR
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NWRT / PAR
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NWRT / PAR

• Specifications
• WSR-88D transmitter (3.2 GHz)
• SPY-1A antenna array
• Passive array of 4,352 elements
• Scans 60 degrees
• 1.5 to 2.5 degree beamwidth
• VCP 12 collection ( 40 seconds per quad)
• Faster once beam multiplexing is implemented

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NWRT / PAR
KTLX 0.5 deg
NWRT 0.75 deg
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NWRT / PAR

• Impact on QPE
• Vertical polarization
• NEXRAD is horizontally polarized
• Reduced sensitivity
• NEXRAD -10 dBZ vs NWRT 5.89 dBZ at 50 km
• Ground clutter
• No clutter filtering implemented yet

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NWRT / PAR

• Current Work
• Beam multiplexing
• Speed up data collection
• Radial data transmission
• Current WDP waits till end of volume
• Allows additional processing
• Severe weather algorithms
• WDSS-II algorithms and display
• System engineering

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NWRT / PAR

• Future Work
• Adaptive scanning
• Improved transmitter dual frequency
• Multi-use applications
• Wind profiling
• Aircraft tracking
• Chemical/Biological profiling
• Dual-Polarization