Test of a Staggered PRT Scheme for the French Radar Network

P. Tabary Centre de Météorologie Radar, Direction des Systèmes d’Observation, Météo France, Trappes, France

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L. Perier Centre de Météorologie Radar, Direction des Systèmes d’Observation, Météo France, Trappes, France

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J. Gagneux Centre de Météorologie Radar, Direction des Systèmes d’Observation, Météo France, Trappes, France

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J. Parent-du-Chatelet Centre de Météorologie Radar, Direction des Systèmes d’Observation, Météo France, Trappes, France

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Abstract

This paper describes the test of a staggered PRT scheme for the French radar network. The design of the staggered scheme has been done in the following context: 1) the scheme is meant to be implemented on existing C-band and S-band radars of the network, the PRF of which cannot, for technical reasons, be increased above their current values (300–400 Hz for C band and 250–300 Hz for S band); 2) the minimum expected Nyquist velocity should be around 30 m s−1; and 3) the Doppler information will essentially be used to retrieve a VAD wind profile and for data assimilation by operational nonhydrostatic numerical prediction models. An operational C-band radar of the network, located in Trappes, near Paris, has been modified in order to allow Doppler processing and a dual-PRT staggered scheme with two low PRFs (PRF1=310 and PRF2=360 Hz corresponding to a ratio of 6/7) has been implemented. Two months of data (July–August 2003) have been analyzed. The performance of the scheme is assessed qualitatively and quantitatively through the computation of the error structure of the various velocities: velocity at PRF1, velocity at PRF2, and combined velocity. The sensitivity of the error structure on the signal-to-noise ratio is documented. A 7 km × 7 km median filter is introduced to reduce dealiasing errors.

Corresponding author address: P. Tabary, Centre de Météorologie Radar, Direction des Systèmes d’Observation, Météo France, 7, rue Teisserenc-de-Bort, 78195 Trappes, France. Email: pierre.tabary@meteo.fr

Abstract

This paper describes the test of a staggered PRT scheme for the French radar network. The design of the staggered scheme has been done in the following context: 1) the scheme is meant to be implemented on existing C-band and S-band radars of the network, the PRF of which cannot, for technical reasons, be increased above their current values (300–400 Hz for C band and 250–300 Hz for S band); 2) the minimum expected Nyquist velocity should be around 30 m s−1; and 3) the Doppler information will essentially be used to retrieve a VAD wind profile and for data assimilation by operational nonhydrostatic numerical prediction models. An operational C-band radar of the network, located in Trappes, near Paris, has been modified in order to allow Doppler processing and a dual-PRT staggered scheme with two low PRFs (PRF1=310 and PRF2=360 Hz corresponding to a ratio of 6/7) has been implemented. Two months of data (July–August 2003) have been analyzed. The performance of the scheme is assessed qualitatively and quantitatively through the computation of the error structure of the various velocities: velocity at PRF1, velocity at PRF2, and combined velocity. The sensitivity of the error structure on the signal-to-noise ratio is documented. A 7 km × 7 km median filter is introduced to reduce dealiasing errors.

Corresponding author address: P. Tabary, Centre de Météorologie Radar, Direction des Systèmes d’Observation, Météo France, 7, rue Teisserenc-de-Bort, 78195 Trappes, France. Email: pierre.tabary@meteo.fr

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  • Browning, K. A., and Wexler R. , 1968: The determination of kinematic properties of a wind field using Doppler radar. J. Appl. Meteor., 7 , 105113.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Curtis, J. N., and Houze R. A. , 2001: A real-time four-dimensional Doppler dealiasing scheme. J. Atmos. Oceanic Technol., 18 , 16741683.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Doviak, R. J., and Zrnic D. S. , 1984: Doppler Radar and Weather Observations. Academic Press, 458 pp.

  • Gray, G., Lewis B. , Vinson J. , and Pratte F. , 1989: A real-time implementation of staggered PRT velocity unfolding. J. Atmos. Oceanic Technol., 6 , 186187.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Holleman, I., 2003: Quality of weather radar wind profiles. KNMI Scientific Rep. WR-2003-02, 72 pp.

  • Holleman, I., and Beekhuis H. , 2003: Analysis and correction of dual-PRF velocity data. J. Atmos. Oceanic Technol., 20 , 443453.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Joe, P., and May P. T. , 2003: Correction of dual PRF velocity errors for operational Doppler weather radars. J. Atmos. Oceanic Technol., 20 , 429442.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lindskog, M., Järvinen H. , and Michelson D. B. , 2000: Assimilation of radar radial winds in the HIRLAM 3D-VAR. Phys. Chem. Earth, 25 , 12431249.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sachidananda, M., and Zrnic D. S. , 2002: An improved clutter filtering and spectral moment estimation algorithm for staggered PRT sequences. J. Atmos. Oceanic Technol., 19 , 20092019.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sugier, J., Parent-du-Châtelet J. , Roquain P. , and Smith A. , 2002: Detection and removal of clutter and anaprop in radar data using a statistical scheme based on echo fluctuation. Proc. Second European Radar Conf., Copernicus GmbH, Delft, Netherlands, 17–24.

  • Tabary, P., Scialom G. , and Germann U. , 2001: Real-time retrieval of the wind from aliased velocities measured by Doppler radars. J. Atmos. Oceanic Technol., 18 , 875882.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Waldteufel, P., and Corbin H. , 1979: On the analysis of single Doppler radar data. J. Appl. Meteor., 18 , 534542.

  • Zrnic, D. S., and Mahapatra P. , 1985: Two methods of ambiguity resolution in pulse Doppler weather radars. IEEE Trans. Aerosp. Electron. Syst., 21 , 470483.

    • Search Google Scholar
    • Export Citation
  • Zrnic, D. S., and Zahrai A. , 2003: Evolution of weather surveillance radars, NSSL’s perspective. Proc. 31st Conf. on Radar Meteorology, Seattle, WA, Amer. Meteor. Soc., 939–941.

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