G O D D A R D S P A C E F L I G H T C E N T E R NASA High-Altitude Precipitation/Wind Radars for Hurricane Research Gerald Heymsfield NASA/Goddard Space Flight Center ([email protected]) Lihua Li /University of Maryland Baltimore/GEST James Carswell /Remote Sensing Solutions, Inc. Outline: •Current high-altitude radars for hurricane research with NASA ER-2 •Future directions with tropospheric wind measurements and surface winds from high-altitude aircraft and high-altitude long endurance UAS (HALE).
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G O D D A R D S P A C E F L I G H T C E N T E R
NASA High-Altitude Precipitation/Wind Radars for
Hurricane Research
NASA High-Altitude Precipitation/Wind Radars for
Hurricane Research
Gerald Heymsfield NASA/Goddard Space Flight Center
([email protected])Lihua Li /University of Maryland Baltimore/GESTJames Carswell /Remote Sensing Solutions, Inc.
Outline:• Current high-altitude radars for hurricane research with NASA ER-2
• Future directions with tropospheric wind measurements and surface winds from high-altitude aircraft and high-altitude long endurance UAS (HALE).
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Science DriversScience Drivers
Targeted observations and real-time information from hurricanes & other extreme weather events in remote regions.
Tropospheric wind measurements with higher spatial and temporal resolution than currently available from lower altitude aircraft
HALE such as Global Hawk currently provide long-duration (>24 hours), high-altitude (>18 km) capability.
More than a decade of high-altitude Doppler wind measurements from ER-2 aircraft over weather systems including tropical storms
G O D D A R D S P A C E F L I G H T C E N T E R
Current Hurricane Research Using ER-2 Doppler Radar
(EDOP)X-band (9.6 GHz)
Current Hurricane Research Using ER-2 Doppler Radar
(EDOP)X-band (9.6 GHz)
•Nadir pointing beam -> derive vertical motions•Fixed forward pointing beam (30 degrees) for derivation of along-track winds and cross-polarization measurements.
•First flown 1995, developed early 1990’s.
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Cloud Radar System (CRS)W-Band (94 GHz)
Cloud Radar System (CRS)W-Band (94 GHz)
>CloudSat simulator>Strongly attenuated by precipitation, large ice.
CRS (94 GHz) EDOP (9.6 GHz)
-->Dual-frequency (X, W-Band) provides information on hydrometeors
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Radar Wind Measurements Motivating Factors for Conical
Scan
Radar Wind Measurements Motivating Factors for Conical
Scan
Radar Wind Sensor (RAWS) (Moore et al., 1992)
Spaceborne radar wind measurement study (X- and Ka-band) with 30o, 35oconical scan funded by NASA to complement Lidar Wind Sounder (LAWS)
Radar Wind Sensor (RAWS) (Moore et al., 1992)
Spaceborne radar wind measurement study (X- and Ka-band) with 30o, 35oconical scan funded by NASA to complement Lidar Wind Sounder (LAWS)
Imaging Wind and Rain Airborne Profiler (IWRAP) (Esteban, Carswell..2005)
P3-based C- and Ku-band, four incidence angle, conical scanner flown in hurricanes the past seveal years
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NASA Conical Scan Radars in Development
NASA Conical Scan Radars in Development
High-Altitude Imaging Wind and Rain Profiler (HIWRAP)
Ku, Ka-Band (14 and 35 GHz) radar funded by NASA Instrument Incubator Program (IIP) Aircraft: WB-57, Global HawkCompletion of basic system: 15 months
UAV Radar (URAD)X-Band (9.3, 9.4 GHz) funded IR&D
Goddard Space Flight CenterAircraft: ER-2?, Global HawkCompletion of basic system: 6 months
High-Altitude Imaging Wind and Rain Profiler (HIWRAP)
Ku, Ka-Band (14 and 35 GHz) radar funded by NASA Instrument Incubator Program (IIP) Aircraft: WB-57, Global HawkCompletion of basic system: 15 months
UAV Radar (URAD)X-Band (9.3, 9.4 GHz) funded IR&D
Goddard Space Flight CenterAircraft: ER-2?, Global HawkCompletion of basic system: 6 months
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NASA High-Altitude Aircraft and HUAS
WB57
Global Hawk
Altitude (kft) 70 631 60 to 65
Maximum Duration (hrs) 8 51 30
Maximum Payload (lbs) 2,900 6,000 2,000-3,000
Max. Microwave Aperture (ft) 2 2.5 4.2 4.3
WB-57ER-2
Not Yet Operational
1Improvements in progress TBD2Conical scan requires large opening
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URAD Measurement ConceptURAD Measurement Concept
Initial development: 2004 Atlantic Seedlings and Hurricane Experiment (ASHE) proposal using Global Hawk to study TS cyclogenesis off the coast of Africa
Nadir capabilities of EDOP, plus a second conical scanning beam to provide estimates of horizontal winds in cloud and the ocean surface winds.
Conical scan provides 3-D surveillance of precipitation, horizontal winds in precip. and surface winds.
Low cost solution using existing radar technologies.
X-Band, separate nadir (9.4 GHz) and scanning radar (9.3 GHz) subsystems, fully scanable antenna up to 35 degree elevation.
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URAD Configuration in Global Hawk
URAD Configuration in Global Hawk
Scanning and fixed nadir antenna
Interface for Global Hawk Two-axis
positioner to achieve conical scan and elevation adjustment.
Two-axis positioner to achieve conical scan and elevation adjustment.
URAD was designed for installation with minimal GH modifications
G O D D A R D S P A C E F L I G H T C E N T E R
URAD HardwareURAD Hardware
TWT transmitter, high voltage powersupply and modulator
Two axis positioner to achieve elevation and azimuth scan
Nadir Magnetron Subsystem
Scanning Receiver hardware
G O D D A R D S P A C E F L I G H T C E N T E R
HIWRAP DevelopmentHIWRAP Development
Technology development emphasis.
Utilize low power solid-state transmitter instead of high power tube-based transmitter - more suitable for high-altitude and space
Develop single aperture antenna for two beams and two frequencies.
Develop high altitude, power efficient real-time digital receiver and processor
GPM frequencies
Technology development emphasis.
Utilize low power solid-state transmitter instead of high power tube-based transmitter - more suitable for high-altitude and space
Develop single aperture antenna for two beams and two frequencies.
Develop high altitude, power efficient real-time digital receiver and processor
GPM frequencies
*3D winds (grid point retrieval) and reflectivity
*Two frequencies and two incidence angles to increase the number independent wind measurements
Based on 10 W Ka-band and 30 W Ku-band power amplifiers
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HIWRAP in Global HawkHIWRAP in Global Hawk
Antenna feedsAntenna reflector
Scanner, slip ring & fiberoptical rotary joint
Aircraft floor
Mounting frame
Radome
Power amplifiers & RF front end
Radar RF/IF
HIWRAP was designed for installation in GH with minimal modifications
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WB-57 Test Flights Planned Summer 2008WB-57 Test Flights Planned Summer 2008
WB-57 6-foot palletRadome for Ku-
and Ka-band
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SummarySummary
Radar-based winds using conical scan from above hurricanes and other extreme weather events is promising approach for high-altitude aircraft, HALE, and space.
HIWRAP hardware completion and flight testing on WB-57 aircraft -> Summer 2008.
Completion of basic URAD system by Fall 2007
Migrate both radars to Global Hawk when one becomes available.
Lidar-based wind instrument (TWiLiTE) due for completion for WB-57 about same time as HIWRAP---> opportunity to remotely measure winds in precipitation-filled and clear regions.
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• TWiLiTE will demonstrate, for the first time, downward looking wind profiles from 18 km to the surface obtained with an airborne direct detection scanning Doppler lidar
• Serves as a system level demonstration and as a technology testbed
• Leverages technology investments from multiple sources
• TWiLiTE is a collaboration of government (NASA/NOAA), university and industry partners
Tropospheric Wind Lidar Technology Experiment (TWiLiTE) Instrument Incubator Program
