Published on

Published in: Technology
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide
  • Note that the HIRAD team requested to fly on both the day before and the day after the Sept 1 flight, but the WB-57 had mechanical problems on those days.
  • Storm center when SFMR crossed it the first time: 73.38W, 26.99N second time: 73.59W, 27.39N
  • Note: 100 sec ~ 10 km P-3 travel
  • TU1.T10.3.ppt

    1. 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. 2. Outline <ul><li>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 </li></ul><ul><li>Instrument development has been led by NASA Marshall Space Flight Center, The University of Central Florida and the University of Michigan </li></ul><ul><li>First airborne science flights were conducted during the Genesis and Rapid Intensification Processes (GRIP) campaign in Fall 2010 </li></ul><ul><li>“ First light” results from overflights of Hurricanes Earl and Karl are reported here </li></ul>
    3. 3. HIRAD Instrument Overview <ul><li>Interferometric Aperture Synthesis Radiometer </li></ul><ul><li>Freq: 4, 5, 6 & 6.6 GHz </li></ul><ul><li>H-pol @ EIA = ± 65° </li></ul><ul><li>Spatial resolution: </li></ul><ul><ul><li>2 km @ nadir </li></ul></ul><ul><ul><li>6 km @ edge of swath </li></ul></ul><ul><li>Swath = 3x A/C altitude </li></ul><ul><ul><li>~ 60 km for GRIP </li></ul></ul><ul><li>Software beam steering </li></ul><ul><ul><li>No moving parts </li></ul></ul>
    4. 4. HIRAD Instrument Block Diagram
    5. 5. HIRAD Integration on WB-57 Aircraft
    6. 6. Hurricane Earl Best Track and HIRAD 1 Sep. Overpass HIRAD overpass
    7. 7. Hurricane Earl Max Windspeed History HIRAD flight
    8. 8. Nearly Coincident HIRAD/WB-57 and SFMR/P-3 Overpasses of Earl on 1 Sep. Storm-centric coordinate system <ul><li>HIRAD/SFMR matchups </li></ul><ul><li>TBs are expected to agree only at the nadir point. </li></ul>
    9. 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. 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. 11. Hurricane Karl Best Track and 3 HIRAD Overpasses on 14, 16 & 17 Sep. Storm center location during HIRAD overpasses indicated by triangles
    12. 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. 13. Summary <ul><li>HIRAD produces SFMR-like TB images over a wide (~3x altitude) cross track swath </li></ul><ul><li>Initial TB calibration/validation is possible using nearly coincident SFMR overpasses </li></ul><ul><li>Final instrument calibration and the development of off-nadir versions of SFMR windspeed and rain rate retrieval algorithms are currently underway </li></ul><ul><li>Future participation in NASA’s Hurricane and Severe Storm Sentinal (HS3) Earth Venture-1 mission </li></ul>