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

Kurt D. HondlDOC/NOAA/OARNational Severe Storms Laboratory

28 June 2005 Hondl - Q2 Workshop 2

CASA

WSR-88D

CASA X-Band

Earth’s curvature Earth’s curvature prevents 72% of the prevents 72% of the atmosphere below atmosphere below 1 km from being 1 km from being

observedobserved

28 June 2005 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.

28 June 2005 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

28 June 2005 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

28 June 2005 Hondl - Q2 Workshop 6

CASA

3 km

6 km

25 km

1

2

3

4

5

6

7

Goal: Map winds, rain below 3 km.

Neighbor radars map “cone of silence” above a radar. Multiple-Doppler wind measurement throughout.

28 June 2005 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

28 June 2005 Hondl - Q2 Workshop 8

CASA – Prototype Radar

28 June 2005 Hondl - Q2 Workshop 9

CASA – Oklahoma Testbed

28 June 2005 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

28 June 2005 Hondl - Q2 Workshop 11

CASA

Radar Engineering ResearchElectronic scanning arraysTechnologies being investigated

Frequency/Phase ArrayPhase/Phase ArrayDiscrete Lens Array

IssuesCostTechnology developmentDual polarization capability

NWRT / PAR

28 June 2005 Hondl - Q2 Workshop 13

NWRT / PAR

Objectives1. 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 2005 Hondl - Q2 Workshop 14

NWRT / PAR

28 June 2005 Hondl - Q2 Workshop 15

NWRT / PARPS CabinetPS Cabinet

APP CabinetAPP Cabinet

New Receiver/Exciter/AWG/PS for LNA/RTC Cabinet

AuxiliaryEquipment(Transformer/Converter/Filters/Junction Boxes)

WSR-88DTransmitter

RotatingTurntable

FAA Warning LightAnd Lightning Rod

StationaryRadome with Zenith Hatch

AntennaTemperatureControl

SupportStructure

SPY-1AAntenna

Pedestal

Concrete RadomeWall & Base

28 June 2005 Hondl - Q2 Workshop 16

NWRT / PAR

SpecificationsWSR-88D transmitter (3.2 GHz)SPY-1A antenna array

Passive array of 4,352 elementsScans ±60 degrees1.5 – to – 2.5 degree beamwidth

VCP 12 collection (~ 40 seconds per quad)Faster once beam multiplexing is implemented

28 June 2005 Hondl - Q2 Workshop 17

NWRT / PAR

KTLX 0.5 deg NWRT 0.75 deg

28 June 2005 Hondl - Q2 Workshop 18

NWRT / PAR

Impact on QPEVertical polarization

NEXRAD is horizontally polarizedReduced sensitivity

NEXRAD -10 dBZ vs NWRT 5.89 dBZ at 50 kmGround clutter

No clutter filtering implemented yet

28 June 2005 Hondl - Q2 Workshop 19

NWRT / PAR

Current WorkBeam multiplexing

Speed up data collectionRadial data transmission

Current WDP waits till end of volumeAllows additional processing

Severe weather algorithmsWDSS-II algorithms and display

System engineering

28 June 2005 Hondl - Q2 Workshop 20

NWRT / PAR

Future WorkAdaptive scanning Improved transmitter – dual frequencyMulti-use applications

Wind profilingAircraft trackingChemical/Biological profiling

Dual-Polarization