- 1. First Tropical Cyclone Overflights by the Hurricane Imaging
Radiometer (HIRAD) Chris Ruf 1 , Sayak Biswas 2 , Mark James 3 ,
Linwood Jones 2 , Tim Miller 3 1. University of Michigan 2.
University of Central Florida 3. NASA Marshall Space Flight Center
College of Engineering Department of Atmospheric, Oceanic &
Space Sciences IGARSS 2011 Vancouver BC, CANADA 26 July 2011
2. Outline
- The Hurricane Imaging Radiometer (HIRAD) is a new airborne
microwave spectrometer designed to be an enhanced imaging version
of the operational Stepped Frequency Microwave Radiometer (SFMR)
that has been used operationally by NOAA for decades to retrieve
surface winds under heavy precipitation
- Instrument development has been led by NASA Marshall Space
Flight Center, The University of Central Florida and the University
of Michigan
- First airborne science flights were conducted during the
Genesis and Rapid Intensification Processes (GRIP) campaign in Fall
2010
- First light results from overflights of Hurricanes Earl and
Karl are reported here
3. HIRAD Instrument Overview
- Interferometric Aperture Synthesis Radiometer
4. HIRAD Instrument Block Diagram 5. HIRAD Integration on WB-57
Aircraft 6. Hurricane Earl Best Trackand HIRAD 1 Sep. Overpass
HIRAD overpass 7. Hurricane Earl Max Windspeed History HIRAD flight
8. Nearly Coincident HIRAD/WB-57 and SFMR/P-3Overpasses of Earl on
1 Sep. Storm-centric coordinate system
- TBs are expected to agree only at the nadir point.
9. HIRAD TB Images at 4.0, 5.0 and 6.6 GHz along Northbound Earl
Overpass 4.0 GHz 5.0 GHz 6.6 GHz 10. HIRAD/SFMR West Leg Overpass
HIRAD Tb@ 4GHz HIRAD Tb@ 5GHz Model Tb@ 4GHz SFMR Wind +50 (m/s)
SFMR Rain +50 (mm/hr) stop start SFMR Flt Dir Model data are Tb s
computed from SFMR wind & rain fields Model Tb@ 5GHz 11.
Hurricane Karl Best Trackand 3 HIRAD Overpasses on 14, 16 & 17
Sep. Storm center location during HIRAD overpasses indicated by
triangles 12. HIRAD 5 GHz TB Image for Karl 16 Sep. Overpass
Storm-centric Longitude (deg) Storm-centric Latitude (deg) Leg 8
Leg 10 Leg 6 13. Summary
- HIRAD produces SFMR-like TB images over a wide (~3x altitude)
cross track swath
- Initial TB calibration/validation is possible using nearly
coincident SFMR overpasses
- Final instrument calibration and the development of off-nadir
versions of SFMR windspeed and rain rate retrieval algorithms are
currently underway
- Future participation in NASAs Hurricane and Severe Storm
Sentinal (HS3) Earth Venture-1 mission