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

1. 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

2. CASA Earth’s curvature prevents 72% of the atmosphere below 1 km from being observed WSR-88D CASA X-Band Hondl - Q2 Workshop

3. 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. Hondl - Q2 Workshop

4. 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 Hondl - Q2 Workshop

5. 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 Hondl - Q2 Workshop

6. 7 6 6 km 5 4 3 km 3 2 1 25 km CASA Goal: Map winds, rain below 3 km. Neighbor radars map “cone of silence” above a radar. Multiple-Doppler wind measurement throughout. Hondl - Q2 Workshop

7. 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 Hondl - Q2 Workshop

8. CASA – Prototype Radar Hondl - Q2 Workshop

9. CASA – Oklahoma Testbed Hondl - Q2 Workshop

10. 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 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 Hondl - Q2 Workshop

11. 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 Hondl - Q2 Workshop

12. NWRT / PAR

13. 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.) Hondl - Q2 Workshop

14. NWRT / PAR Hondl - Q2 Workshop

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

16. 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 Hondl - Q2 Workshop

17. NWRT / PAR KTLX 0.5 deg NWRT 0.75 deg Hondl - Q2 Workshop

18. 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 Hondl - Q2 Workshop

19. 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 Hondl - Q2 Workshop

20. NWRT / PAR • Future Work • Adaptive scanning • Improved transmitter – dual frequency • Multi-use applications • Wind profiling • Aircraft tracking • Chemical/Biological profiling • Dual-Polarization Hondl - Q2 Workshop