Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 13 5 2009 10.5194/hess-13-651-2009 http://www.hydrol-earth-syst-sci.net/13/651/2009/ http://www.hydrol-earth-syst-sci.net/13/651/2009/hess-13-651-2009.html http://www.hydrol-earth-syst-sci.net/13/651/2009/hess-13-651-2009.pdf 651 661 2009-05-26 A comparative analysis of two wind velocity retrieval techniques by using a single Doppler radar H.-C. Lim D.-I. Lee leedi@pknu.ac.kr School of Mechanical Engineering, PuKyong National University, San 100, Yongdang-Dong, Nam-Gu, Busan, 608-739, South Korea Department of Environment and Atmospheric Science, PuKyong National University, 599-1, Daeyon-Dong, Nam-Gu, Busan, 608-737, South Korea This study compares the theoretical basis of the two wind velocity retrieval methods, Velocity Azimuth Display (VAD) and Velocity Area Display (VARD) by using data obtained by a single Doppler radar. Two pre-assumed shapes of the wind velocity distribution with altitude are considered, uniform and parabolic. The former presents an approximation of the non-sheared or low-sheared wind flow in the upper troposphere, while the latter is a simplified representation of the Atmospheric Boundary Layer (ABL) in lower troposphere or high-sheared wind flow at the edges of the tropospheric jet streams. Both techniques for the wind velocity retrieval considered in this study are reformulated in order to get more precise information on the wind velocity components. An algorithm is proposed to decrease the uncertainty in retrieving by evaluating the coefficients of the polynomial equation and applying a transfer function with respect to the angle formed between the wind flow direction and direction of radar beam. It is concluded that, provided the formulated transformation functions are used, the application of the VAD and VARD techniques to the single-Doppler data may be an invaluable tool for solving various climate and wind engineering problems. Anderson, T.: VAD winds from C band Ericsson Doppler Weather Radars, Meteor. Z., 7, 309–319, 1998. Armstrong, G. and Donaldson Jr., R.: Plan shear indicator for realtime Doppler radar identification of hazardous storms, J. Appl. Meteor., 8, 376–383, 1969. Blane, M. and Lei, Z.: The 3L Algorithm for Fitting Implicit Polynomial Curves and Surfaces to Data, IEEE Transactions on Pattern Analysis and Machine Intelligence, 22, 298–313, 2000. Browning, K. and Wexler, R.: The determination of kinematic properties of a wind field using Doppler radar, J. Appl. Meteor., 7, 105–113, 1968. Caton, P.: The measurement of wind and convergence by Doppler Radar, in: Preprints 10th Weather Radar Conference, 1963. Easterbrook, C.: Estimating Horizontal Wind Fields by Two Dimensional Curve Fitting of Single Doppler Radar Measurements, in: Preprints 16th Radar Meteorology Conference, 1975. Lhermitte, R. and Atlas, D.: Precipitation motion by pulse Doppler radar, in: Preprints 9th Conf. on Radar Meteorology, 1961. Matejka, T.: Concurrent extended vertical velocity azimuth display (CEVAD), in: Preprints 26th Conf. on Radar Meteorology, 1993. Srivastava, R., Matejka, T., and Lorello, T.: Doppler radar study of the trailing anvil region associated with a squall line, J. Atmos. Sci., 43, 356–377, 1986. Waldteufel, P. and Corbin, H.: On the analysis of single-Doppler radar data, J. Appl. Meteorol., 18, 532–542, 1978. Wood, V. and Brown, R.: Single-Doppler velocity signature interpretation of non-divergent environmental winds, J. Atmos. Ocean. Technol., 3, 114–128, 1986. Wood, V. and Brown, R.: Effects of radar sampling on single-Doppler velocity signatures of mesocyclones and tornadoes., Wea. Forecast., 12, 928–938, 1997.