1. 03/06/2007 IHC New Orleans1 Potential Applications of the Proposed Phase Array Doppler Radar on the NSF/NCAR C-130 in Hurricane Reconnaissance 61st Interdepartmental Hurricane Conference NCAR Earth Observing Laboratory Wen-Chau Lee, J. Vivekanandan, Eric Loew, James Moore

2. 03/06/2007 IHC New Orleans2 Introduction 2/3/07, Jeff Hawkins message to Tropical-storms list: “ …Which highlights one of my favorite subjects: the need for inner-core aircraft penetrations in the WPAC to help validate satellite intensity/structure algorithms that have zip to go on since 1993 in the most active TC basin.” Wen-Chau Lee: “Wouldn't it be nice to have airborne Doppler radar to go with the recon in WPAC? The dataset will be able to validate the microwave sensors on satellite and give a more definite 3D structure of the typhoon (wind and precipitation) than those can be provided by the insitu measurement.” Jeff: “Which aircraft are we talking about here?” Wen-Chau: “The concept of CAPRIS on NSF/NCAR C-130 and its potential applications on Air Force C-130. … Just realized that you are the session co-chair of my concept paper at IHC next Tuesday.” Jeff: “Yap, see you there.”

3. 03/06/2007 IHC New Orleans3 Current Hurricane Reconnaissance Capability Central Pressure Insitu (u,v,w,T, Td, etc) ExpendableRemote sensors 3-D Dual- Doppler (u, v, w, and Z) Cloud Physics (in situ) Cloud Physics (polari- metric radar) Air Force C-130s Yes DropsondeSFMRNo NOAA WP- 3Ds yesYesDropsonde, AXBT, AXCP, AXCP, Drifting Buoys SFMR, C-SCAT Yes No NOAA Gulfstream IV NoYesDropsondeNoYes (soon) No

4. 03/06/2007 IHC New Orleans4 Why Airborne Dual-Doppler Radar Capability Is Critical in Hurricane Reconnaissance, Operations, and Research  It is currently the only means to probe 3-D hurricane inner core kinematic structures at a spatial resolution ~1 km  Hurricane inner core is the critical region governing hurricane evolution and intensity change  Basic understanding of hurricane inner core dynamics will improve numerical model physics and lead to better prediction  Improved description on hurricane inner core structure by assimilating Doppler radar data into hurricane model has been identified as one of the critical paths toward improving intensity forecast

5. 03/06/2007 IHC New Orleans5 How About Polarimetric Radar Data? Polarimetric radar data combined with fuzzy logic technique can identify particle type, shape, rain rate, etc. in precipitation systems. Microphysical information in TC has been obtained by insitu measurements only at flight levels. Only a handful of TCs have been sampled by ground-based polarimetric radars. This is an area that has not been explored in TCs.

6. 03/06/2007 IHC New Orleans6 InstrumentScience Aairborne polarimetric centimeter Doppler Radar – C or X bands Hurricane, severe storms, Convection initiation, tropical meteorology. Kinematics and microphysical processes. Pod based dual-wavelength, dual- polarization, millimeter wave Doppler radar – W, Ka Bands Cloud and drizzle microphysics, ice microphysics, and cloud radiation properties H 2 O Differential Absorption Lidar (DIAL), O 3 DIAL, Doppler Wind Lidar (UTLS and PBL systems) CO 2 DIAL, Vegetation Canopy Lidar Climate change, fluxes and transport of water vapor, ozone, and pollutants from boundary layer to UTLS, gravity waves Community Airborne Platform Remote-sensing Interdisciplinary Suite (CAPRIS) on C-130

7. 03/06/2007 IHC New Orleans7 CAPRIS Airborne Centimeter Radar Configurations Four C-band active element scanning array (AESA) conformal antennas –Beam width 2.1°x1.6°/ 2.2°x2.3° –Sensitivity -4 dBZ at 10 km –Gate spacing 150 m Dual Doppler (V, σ v ) 2 x along track resolution (~200 m) of current ELDORA system due to scanning agility, simultaneous beams from all four antennas, and slower polarimetric scanning Dual polarization H,V linear – Z H, Z DR, K DP, RHO HV Antenna Size: ~2.0 m X 1.5 m ~2000 elements

8. 03/06/2007 IHC New Orleans8 Rear AESA Upper AESA Starboard AESA Port AESA W, Ka band Pod C-130 front view Possible CAPRIS Radar Positions on C-130

9. Composite “Surveillance” Scan

10. Resolution Makes A Difference!

11. Vertical X-section in Hurricane Rita at 500 m Resolution (From John Gamache 3D Analysis) Eye

12. 03/06/2007 IHC New Orleans12 Potential Applications to Hurricane Reconnaissance and Research  The AESA radar system can be installed on Air Force C-130s to collect high-resolution 3-D inner core kinematic and microphysical structures during all reconnaissance missions  Real-time dual-Doppler winds can be transmitted back to NHC and Qced Doppler radar radial velocities and polarimetric data can be transmitted to NCEP for radar data assimilation in hurricane models for every TC that has recon flights  Generate expanded hurricane database for the Atlantic basin  Impact the operation and research community - validation of satellite products, process studies, design observing strategy, …

13. 03/06/2007 IHC New Orleans13 Mid-Size Infrastructure for Atmospheric Sciences ATM maintains a mid-size infrastructure account that can be used to build and/or acquire community facilities. Several groups are competing for available funds General Considerations (highlights) Community facility It is expected to take five years to develop CAPRIS cm radar after NSF approval. Partnerships with university, federal, private, or international institutions are encouraged. EOL has been encouraged to submit a White-paper for CAPRIS Key time for community comment and advice on present concepts Revised White Paper Document due to NSF Mid March 2007 NSF will evaluate all white papers and invite several projects to submit final proposal in Fall 2007 The NSF Opportunity

14. 03/06/2007 IHC New Orleans14 Partnership and Collaboration Opportunities CAPRIS has established a strategic partnership with MIT/Lincoln Laboratory to develop the AESA component. Lincoln Laboratory is developing a Multifunction Phased Array Radar (MPAR), sponsored by FAA, NWS and DoD/DHS, to replace and consolidate existing radars operated by FAA, NWS and DoD. MPAR will provide terminal-area and long-range aircraft surveillance and weather measurements. AESA technology allows 3-D volumetric coverage of hurricane inner core kinematic and microphysical structures. There is a unique opportunity to leverage these complementary developments for the benefit of hurricane reconnaissance, operation, and research.

15. 03/06/2007 IHC New Orleans15 Questions and Comments For further information, contact: Jim Moore (jmoore@ucar.edu)jmoore@ucar.edu Wen-Chau Lee (wenchau@ucar.edu)wenchau@ucar.edu Visit the website: http://www.eol.ucar.edu/development/capris/

16. 03/06/2007 IHC New Orleans16 END

17. 03/06/2007 IHC New Orleans17 S-Pol X-Pol corrected. X-Pol Reflectivity Total attenuation Not good correction S and X-band Radar Observations

18. 03/06/2007 IHC New Orleans18 AESA Characteristics PARAMETERX-BandC-Band Wavelength3.2 cm5.045 cm Dimensions (w x l)0.93 m x 1.18 m1.46 m x 1.86 m 3dB Beamwidth (broadside)2.1° x 1.6° 3dB Beamwidth (20° Az, 45° El)2.1° x 1.6° Gain (broadside)38 dBi Gain (20° az, 45° el)36 dBi Element Spacing (w x l)0.725 λ x 0.575 λ Elements/Panel (w x l)10 x 16 Panels16 Total Elements2560 First Sidelobe< -25 dB Cross-Pol Isolation> 30 dB Noise Figure3.5 dB Transmit Power (peak)2.9 kW @ 10% duty EIRP (worst case)90 dBm avg.

19. 03/06/2007 IHC New Orleans19 CM-Wave Radar Performance X-BandsC-Bands Beam Width (nominal) 2.76˚ x 1.76˚ Along Track Spacing ** 75 m Range Resolution 150 m Sensitivity (single hit, no attenuation) -8.6 dBZ @ 10 km -6.2 dBZ @ 10 km Sensitivity (single hit, 10 mm/hr rain) -6.2 dBZ @ 10 km -5.8 dBZ @ 10 km PolarizationDual: H or V ** 140 deg/sec scan rate