Editorial Type:
Article
Article Type:
Research Article

Considerations for Oversampling in Azimuth on the Phased Array Weather Radar

Lesya Borowska Advanced Radar Research Center, University of Oklahoma, Norman, Oklahoma

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Guifu Zhang School of Meteorology, and School of Electrical and Computer Engineering, and Advanced Radar Research Center, University of Oklahoma, Norman, Oklahoma

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Dusan S. Zrnić National Severe Storms Laboratory, Norman, Oklahoma

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Print Publication:
01 Sep 2015
DOI:
https://doi.org/10.1175/JTECH-D-15-0018.1
Page(s):
1614–1629
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Abstract

When spectral moments in the azimuth are spaced by less than a beamwidth, it is called oversampling. Superresolution is a type of oversampling that refers to sampling at half a beamwidth on the national network of Doppler weather radars [Weather Surveillance Radar-1988 Doppler (WSR-88D)]. Such close spacing is desirable because it extends the range at which small severe weather features, such as tornadoes or microbursts, can be resolved. This study examines oversampling for phased array radars. The goal of the study is to preserve the same effective beamwidth as on the WSR-88D while obtaining smaller spectral moment estimate errors at the same or faster volume update times. To that effect, a weighted average of autocorrelations of radar signals from three consecutive radials is proposed. Errors in three spectral moments obtained from these autocorrelations are evaluated theoretically. Methodologies on how to choose weights that preserve the desirable effective beamwidth are presented. The results are demonstrated on the fields of spectral moments obtained with the National Weather Radar Testbed (NWRT), a phased array weather radar at NOAA’s National Severe Storms Laboratory (NSSL).

Corresponding author address: Dr. L. Borowska, Advanced Radar Research Center, University of Oklahoma, 120 David L. Boren Blvd., Norman, OK 73072. E-mail: lesya.borowska-1@ou.edu

Abstract

When spectral moments in the azimuth are spaced by less than a beamwidth, it is called oversampling. Superresolution is a type of oversampling that refers to sampling at half a beamwidth on the national network of Doppler weather radars [Weather Surveillance Radar-1988 Doppler (WSR-88D)]. Such close spacing is desirable because it extends the range at which small severe weather features, such as tornadoes or microbursts, can be resolved. This study examines oversampling for phased array radars. The goal of the study is to preserve the same effective beamwidth as on the WSR-88D while obtaining smaller spectral moment estimate errors at the same or faster volume update times. To that effect, a weighted average of autocorrelations of radar signals from three consecutive radials is proposed. Errors in three spectral moments obtained from these autocorrelations are evaluated theoretically. Methodologies on how to choose weights that preserve the desirable effective beamwidth are presented. The results are demonstrated on the fields of spectral moments obtained with the National Weather Radar Testbed (NWRT), a phased array weather radar at NOAA’s National Severe Storms Laboratory (NSSL).

Corresponding author address: Dr. L. Borowska, Advanced Radar Research Center, University of Oklahoma, 120 David L. Boren Blvd., Norman, OK 73072. E-mail: lesya.borowska-1@ou.edu
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  • Atkins, N. R., Butler K. M. , Flynn K. R. , and Wakimoto R. , 2014: An integrated damage, visual, and radar analysis of the 2013 Moore, Oklahoma, EF5 tornado. Bull. Amer. Meteor. Soc., 95, 1549–1561, doi:10.1175/BAMS-D-14-00033.1.

    • Search Google Scholar
    • Export Citation

  • Brown, R. A., Wood V. T. , and Sirmans D. , 2002: Improved tornado detection using simulated and actual WSR-88D data with enhanced resolution. J. Atmos. Oceanic Technol., 19, 1759–1771, doi:10.1175/1520-0426(2002)019<1759:ITDUSA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Burgess, D., and Coauthors, 2014: 20 May 2013 Moore, Oklahoma, tornado: Damage survey and analysis. Wea. Forecasting, 29, 1229–1237, doi:10.1175/WAF-D-14-00039.1.

    • Search Google Scholar
    • Export Citation

  • Doviak, R. J., and Zrnić D. S. , 2006: Doppler Radar and Weather Observations. Dover Publications, 562 pp.

  • Doviak, R. J., and Zrnić D. S. , 2015: Errata and supplements. NOAA, 53 pp. [Available online at http://www.nssl.noaa.gov/publications/books/Errata_2nd_edition_3rd_and_4th%20prt_wo_comments.pdf?v=15jun2015.]

  • Fang, M., Doviak R. J. , and Melnikov V. , 2004: Spectrum width measured by WSR-88D: Error sources and statistics of various weather phenomena. J. Atmos. Oceanic Technol., 21, 888–904, doi:10.1175/1520-0426(2004)021<0888:SWMBWE>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Hubbert, J. C., Dixon M. , and Ellis S. M. , 2009: Weather radar ground clutter. Part II: Real-time identification and filtering. J. Atmos. Oceanic Technol., 26, 1181–1197, doi:10.1175/2009JTECHA1160.1.

    • Search Google Scholar
    • Export Citation

  • Melnikov, V. M., 2004: Simultaneous transmission mode for the polarimetric WSR-88D: Statistical biases and standard deviations of polarimetric variables. NOAA/NSSL Rep., 84 pp. [Available online at www.nssl.noaa.gov/publications/wsr88d_reports/SHV_statistics.pdf.]

  • Meymaris, G., 2012: Updates to the hybrid spectrum width estimator. 28th Conf. on Interactive Information and Processing Systems (IIPS) for Meteorology, Oceanography, and Hydrology, New Orleans, LA, Amer. Meteor. Soc., 9A.6. [Available online at https://ams.confex.com/ams/92Annual/webprogram/Paper202232.html.]

  • Meymaris, G., Williams J. K. , and Hubbert J. C. , 2009: Performance of a proposed hybrid spectrum width estimator for the NEXRAD ORDA. 25th Conf. on Interactive Information and Processing Systems (IIPS) for Meteorology, Oceanography, and Hydrology, Phoenix, AZ, Amer. Meteor. Soc., 11B.1. [Available online at https://ams.confex.com/ams/89annual/techprogram/paper_145958.htm.]

  • Sachidananda, M., and Zrnić D. S. , 1999: Systematic phase codes for resolving range overlaid signals in a Doppler weather radar. J. Atmos. Oceanic Technol., 16, 1351–1363, doi:10.1175/1520-0426(1999)016<1351:SPCFRR>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Siggia, A. D., and Passarelli R. E. Jr., 2004: Gaussian model adaptive processing (GMAP) for improved ground clutter cancellation and moment calculation. Third European Conference on Radar in Meteorology and Hydrology (ERAD) together with the COST 717 Final Seminar, ERAD Publication Series, Copernicus, 67–73.

  • Torres, M. S., and Curtis C. , 2007: Initial implementation of super-resolution data on the NEXRAD network. 23rd Conf. on Interactive Information and Processing Systems (IIPS) for Meteorology, Oceanography, and Hydrology, San Antonio, TX, Amer. Meteor. Soc, 5B.10. [Available online at https://ams.confex.com/ams/87ANNUAL/techprogram/paper_116240.htm.]

  • Weber, M. E., Cho J. Y. N. , Herd J. S. , Flavin J. M. , Benner W. E. , and Torok G. S. , 2007: The next-generation multimission U.S. surveillance radar network. Bull. Amer. Meteor. Soc., 88, 1739–1751, doi:10.1175/BAMS-88-11-1739.

    • Search Google Scholar
    • Export Citation

  • Wurman, J., Kosiba K. , Robinson P. , and Marshall T. , 2014: The role of multiple-vortex tornado structure in causing storm researcher fatalities. Bull. Amer. Meteor. Soc., 95, 31–45, doi:10.1175/BAMS-D-13-00221.1.

    • Search Google Scholar
    • Export Citation

  • Zrnić, D. S., 1975: Simulation of weatherlike Doppler spectra and signals. J. Appl. Meteor., 14, 619–620, doi:10.1175/1520-0450(1975)014<0619:SOWDSA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Zrnić, D. S., 1977: Spectral moment estimates from correlated pulse pairs. IEEE Trans. Aerosp. Electron. Syst., AES-13, 344–354, doi:10.1109/TAES.1977.308467.

    • Search Google Scholar
    • Export Citation

  • Zrnić, D. S., 2011: Doppler radar for USA weather surveillance. Doppler Radar Observations—Weather Radar, Wind Profiler, Ionospheric Radar, and Other Advanced Applications, J. Bech and J. L. Chau, Eds., InTech, 3–32.

  • Zrnić, D. S., and Doviak R. J. , 1976: Effective antenna pattern of scanning radars. IEEE Trans. Aerosp. Electron. Syst., AES-12, 551–555, doi:10.1109/TAES.1976.308254.

    • Search Google Scholar
    • Export Citation

  • Zrnić, D. S., and Coauthors, 2007: Agile-beam phased array radar for weather observations. Bull. Amer. Meteor. Soc., 88, 1753–1766, doi:10.1175/BAMS-88-11-1753.

    • Search Google Scholar
    • Export Citation
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