• Barrick, D. E., 1968: Rough surface scattering based on the specular point theory. IEEE Trans. Antennas Propag., 16, 449454, doi:10.1109/TAP.1968.1139220.

    • Search Google Scholar
    • Export Citation
  • Barrick, D. E., 1974: Wind dependence of quasi-specular microwave sea scatter. IEEE Trans. Antennas Propag., 22, 135136, doi:10.1109/TAP.1974.1140736.

    • Search Google Scholar
    • Export Citation
  • Battaglia, A., Ajewole M. O. , and Simmer C. , 2006: Evaluation of radar multiple-scattering effects from a GPM perspective. Part II: Model results. J. Appl. Meteor. Climatol., 45, 16481664, doi:10.1175/JAM2425.1.

    • Search Google Scholar
    • Export Citation
  • Doviak, R. J., and Zrnić D. S. , 1993: Doppler Radar and Weather Observations. Academic Press, 562 pp.

  • Goodberlet, M., and PopStefanija I. , 2013: Retrievals of wind and rain rate from combined measurements of up-looking and down-looking SFMRs. 67th Interdepartmental Hurricane Conf./Tropical Cyclone Research Forum, College Park, MD, NOAA, S7-05. [Available online at www.ofcm.noaa.gov/ihc13/Presentations/7-Session/05-S7-PopStefanija-updownSFMR-2013.pptx.]

  • Jiang, H., Black P. G. , Zipser E. J. , Marks F. D. Jr., and Uhlhorn E. W. , 2006: Validation of rain-rate estimation in hurricanes from the stepped frequency microwave radiometer: Algorithm correction and error analysis. J. Atmos. Sci., 63, 252267, doi:10.1175/JAS3605.1.

    • Search Google Scholar
    • Export Citation
  • Lakshmanan, V., Smith T. , Hondl K. , Stumpf G. , and Witt A. , 2006: A real-time, three-dimensional, rapidly updating, heterogeneous radar merger technique for reflectivity, velocity, and derived products. Wea. Forecasting, 21, 802823, doi:10.1175/WAF942.1.

    • Search Google Scholar
    • Export Citation
  • Matrosov, S. Y., 2005: Attenuation-based estimates of rainfall rates aloft with vertically pointing Ka-band radars. J. Atmos. Oceanic Technol., 22, 4354, doi:10.1175/JTECH-1677.1.

    • Search Google Scholar
    • Export Citation
  • Matrosov, S. Y., 2011: CloudSat measurements of landfalling Hurricanes Gustav and Ike (2008). J. Geophys. Res., 116, D01203, doi:10.1029/2010JD014506.

    • Search Google Scholar
    • Export Citation
  • Matrosov, S. Y., May P. T. , and Shupe M. D. , 2006: Rainfall profiling using Atmospheric Radiation Measurement Program vertically pointing 8-mm wavelength radars. J. Atmos. Oceanic Technol., 23, 14781491, doi:10.1175/JTECH1957.1.

    • Search Google Scholar
    • Export Citation
  • Meneghini, R., Jones J. A. , Iguchi T. , Okamoto K. , and Kwiatkowski J. , 2004: A hybrid surface reference technique and its application to the TRMM precipitation radar. J. Atmos. Oceanic Technol., 21, 16451658, doi:10.1175/JTECH1664.1.

    • Search Google Scholar
    • Export Citation
  • Uhlhorn, E. W., and Black P. G. , 2003: Verification of remotely sensed surface winds in hurricanes. J. Atmos. Oceanic Technol., 20, 99116, doi:10.1175/1520-0426(2003)020<0099:VORSSS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Uhlhorn, E. W., and Klotz B. W. , 2012: Improved SFMR surface wind measurements in intense rain conditions. Progress Rep. for Year 1, NOAA Joint Hurricane Testbed Program, NOAA/NWS/NCEP/National Hurricane Center, 8 pp. [Available online at http://www.nhc.noaa.gov/jht/11-13reports/Uhlhorn_yr1_annualrpt.pdf.]

  • Uhlhorn, E. W., Black P. G. , Franklin J. L. , Goodberlet M. , Carswell J. , and Goldstein A. S. , 2007: Hurricane surface wind speed measurements from an operational stepped frequency microwave radiometer. Mon. Wea. Rev., 135, 30703085, doi:10.1175/MWR3454.1.

    • Search Google Scholar
    • Export Citation
  • Valenzuela, G. R., 1978: Theories for the interaction of electromagnetic and oceanic waves—A review. Bound.-Layer Meteor., 13, 6185, doi:10.1007/BF00913863.

    • Search Google Scholar
    • Export Citation
  • Walsh, E. J., Vandemark D. C. , Friehe C. A. , Burns S. P. , Khelif D. , Swift R. N. , and Scott J. F. , 1998: Measuring sea surface mean square slope with a 36-GHz scanning radar altimeter. J. Geophys. Res.,103, 12 587−12 601, doi:10.1029/97JC02443.

  • Walsh, E. J., and Coauthors, 2002: Hurricane directional wave spectrum spatial variation at landfall. J. Phys. Oceanogr., 32, 16671684, doi:10.1175/1520-0485(2002)032<1667:HDWSSV>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Walsh, E. J., Banner M. L. , Wright C. W. , Vandemark D. C. , Chapron B. , Jensen J. , and Lee S. , 2008: The Southern Ocean Waves Experiment. Part III: Sea surface slope statistics and near-nadir remote sensing. J. Phys. Oceanogr., 38, 670685, doi:10.1175/2007JPO3771.1.

    • Search Google Scholar
    • Export Citation
  • Wright, C. W., Walsh E. J. , Vandemark D. , Krabill W. B. , Houston S. H. , Powell M. D. , Black P. G. , and Marks F. D. , 2001: Hurricane directional wave spectrum spatial variation in the open ocean. J. Phys. Oceanogr., 31, 24722488, doi:10.1175/1520-0485(2001)031<2472:HDWSSV>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Zhang, J., and Coauthors, 2011: National Mosaic and Multi-Sensor QPE (NMQ) system: Description, results, and future plans. Bull. Amer. Meteor. Soc., 92, 13211338, doi:10.1175/2011BAMS-D-11-00047.1.

    • Search Google Scholar
    • Export Citation
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Airborne Rain-Rate Measurement with a Wide-Swath Radar Altimeter

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  • 1 ProSensing, Inc., Amherst, Massachusetts
  • | 2 Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, and Physical Sciences Division, NOAA/Earth System Research Laboratory, Boulder, Colorado
  • | 3 NOAA/National Severe Storms Laboratory, Norman, Oklahoma
  • | 4 Hurricane Research Division, NOAA/AOML, Miami, Florida
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Abstract

The NOAA Wide-Swath Radar Altimeter (WSRA) uses 80 narrow beams spread over ±30° in the cross-track direction to generate raster lines of sea surface topography at a 10-Hz rate from which sea surface directional wave spectra are produced. A ±14° subset of the backscattered power data associated with the topography measurements is used to produce independent measurements of rain rate and sea surface mean square slope at 10-s intervals. Theoretical calculations of rain attenuation at the WSRA 16.15-GHz operating frequency using measured drop size distributions for both mostly convective and mostly stratiform rainfall demonstrate that the WSRA absorption technique for rain determination is relatively insensitive to both ambient temperature and the characteristics of the drop size distribution, in contrast to reflectivity techniques. The variation of the sea surface radar reflectivity in the vicinity of a hurricane is reviewed. Fluctuations in the sea surface scattering characteristics caused by changes in wind speed or the rain impinging on the surface cannot contaminate the rain measurement because they are calibrated out using the WSRA measurement of mean square slope. WSRA rain measurements from a NOAA WP-3D hurricane research aircraft off the North Carolina coast in Hurricane Irene on 26 August 2011 are compared with those from the stepped frequency microwave radiometer (SFMR) on the aircraft and the Next Generation Weather Radar (NEXRAD) National Mosaic and Multi-Sensor Quantitative Precipitation Estimation (QPE) system.

Additional affiliation: Physical Sciences Division, NOAA/Earth System Research Laboratory, Boulder, Colorado.

Additional affiliation: Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida.

Corresponding author address: Ivan PopStefanija, ProSensing, Inc, 107 Sunderland Road, Amherst, MA 01002-1098. E-mail: popstefanija@prosensing.com

Abstract

The NOAA Wide-Swath Radar Altimeter (WSRA) uses 80 narrow beams spread over ±30° in the cross-track direction to generate raster lines of sea surface topography at a 10-Hz rate from which sea surface directional wave spectra are produced. A ±14° subset of the backscattered power data associated with the topography measurements is used to produce independent measurements of rain rate and sea surface mean square slope at 10-s intervals. Theoretical calculations of rain attenuation at the WSRA 16.15-GHz operating frequency using measured drop size distributions for both mostly convective and mostly stratiform rainfall demonstrate that the WSRA absorption technique for rain determination is relatively insensitive to both ambient temperature and the characteristics of the drop size distribution, in contrast to reflectivity techniques. The variation of the sea surface radar reflectivity in the vicinity of a hurricane is reviewed. Fluctuations in the sea surface scattering characteristics caused by changes in wind speed or the rain impinging on the surface cannot contaminate the rain measurement because they are calibrated out using the WSRA measurement of mean square slope. WSRA rain measurements from a NOAA WP-3D hurricane research aircraft off the North Carolina coast in Hurricane Irene on 26 August 2011 are compared with those from the stepped frequency microwave radiometer (SFMR) on the aircraft and the Next Generation Weather Radar (NEXRAD) National Mosaic and Multi-Sensor Quantitative Precipitation Estimation (QPE) system.

Additional affiliation: Physical Sciences Division, NOAA/Earth System Research Laboratory, Boulder, Colorado.

Additional affiliation: Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida.

Corresponding author address: Ivan PopStefanija, ProSensing, Inc, 107 Sunderland Road, Amherst, MA 01002-1098. E-mail: popstefanija@prosensing.com
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