CASA – Collaborative Adaptive Sensing of the Atmosphere NWRT/PAR – National Weather Radar Testbed / Phased Array Radar Kurt D. Hondl DOC/NOAA/OAR National Severe Storms Laboratory

28 June 2005Hondl - Q2 Workshop2 CASA WSR-88D CASA X-Band Earth’s curvature prevents 72% of the atmosphere below 1 km from being observed

28 June 2005Hondl - Q2 Workshop3 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.

28 June 2005Hondl - Q2 Workshop4 CASA What is DCAS? D istributive concept: a network of radars with overlapping beam coverage C ollaborative: multiple radar nodes communicating with one another A daptive: ability to adapt to features being observed and end-user needs S ensing: radars designed using state-of-the-art solid-state, phased-array technology

28 June 2005Hondl - Q2 Workshop5 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 MC&C - 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

28 June 2005Hondl - Q2 Workshop6 CASA 3 km 6 km 25 km Goal: Map winds, rain below 3 km. Neighbor radars map “cone of silence” above a radar. Multiple-Doppler wind measurement throughout.

28 June 2005Hondl - Q2 Workshop7 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 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

28 June 2005Hondl - Q2 Workshop8 CASA – Prototype Radar

28 June 2005Hondl - Q2 Workshop9 CASA – Oklahoma Testbed

28 June 2005Hondl - Q2 Workshop10 CASA – QPE Research IP2 Objectives (Rain & Urban Flooding) Investigate QPE (Houston testbed) Collaboration with Texas Medical Center Covering watershed for Bray’s Bayou Site-specific forecasts at scales km 2 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

28 June 2005Hondl - Q2 Workshop11 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

NWRT / PAR

28 June 2005Hondl - Q2 Workshop13 NWRT / PAR Objectives 1. To demonstrate the effectiveness of a phased array radar in providing longer lead time for severe storm warnings. 2. To provide a research testbed leading to the development of improved/new weather radars for the 21st century 3. To support meteorological research into the evolution of hazardous weather events resulting in an enhanced capability to detect and predict severe weather 4. To provide rapid update data for initialization of numerical models that will improve forecasting and nowcasting capability. 5. To provide a platform for investigating feasibility of dual-use applications from a single radar ( I.e. weather, aircraft tracking, etc.)

28 June 2005Hondl - Q2 Workshop14 NWRT / PAR

28 June 2005Hondl - Q2 Workshop15 NWRT / PAR PS Cabinet APP Cabinet New Receiver /Exciter/AWG /PS for LNA /RTC Cabinet Auxiliary Equipment (Transformer/ Converter/Filters/ Junction Boxes) WSR-88D Transmitter Rotating Turntable FAA Warning Light And Lightning Rod Stationary Radome with Zenith Hatch Antenna Temperature Control Support Structure SPY-1A Antenna Pedestal Concrete Radome Wall & Base

28 June 2005Hondl - Q2 Workshop16 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

28 June 2005Hondl - Q2 Workshop17 NWRT / PAR KTLX 0.5 degNWRT 0.75 deg

28 June 2005Hondl - Q2 Workshop18 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

28 June 2005Hondl - Q2 Workshop19 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

28 June 2005Hondl - Q2 Workshop20 NWRT / PAR Future Work Adaptive scanning Improved transmitter – dual frequency Multi-use applications Wind profiling Aircraft tracking Chemical/Biological profiling Dual-Polarization