Radar reflectivity calibration using differential propagation phase measurement

estimated from power measurements. Comparison of the direct estimate of propagation phase (F m ) measurement, which is unaffected by absolute calibration of the radar system, with the estimated propagation phase (F e ) from power measurements is the basis for the calibration method. Polarization measurements such as reflectivity (Z ), differential reflectivity (ZDR), and differential propagation phase (FDP) are sensitive to drop size distribution (DSD) and mean drop shape. It is important to devise a calibration technique relatively unperturbed by changes in DSD and drop shape. Statistical fluctuation in F e is derived to estimate the accuracy of the calibration procedure, raindrop shape, and attenuation. The proposed method is applied for calibrating reflectivity measurements of the National Center for Atmospheric Research (NCAR) S-band polarization radar (S-Pol) in midlatitude, subtropical, and tropical rain events. INDEX TERMS: 3354 Meteorology and Atmospheric Dynamics: Precipitation (1854); 3360 Meteorology and Atmospheric Dynamics: Remote sensing; 3394 Meteorology and Atmospheric Dynamics: Instruments and techniques; 6904 Radio Science: Atmospheric propagation; 6969 Radio Science: Remote sensing; KEYWORDS: polarization radar calibration, reflectivity, differential reflectivity, differential phase, raindrop size distribution

[1]  V. Chandrasekar,et al.  Raindrop axis ratios and size distributions in Florida rainshafts: an assessment of multiparameter radar algorithms , 1998, IEEE Trans. Geosci. Remote. Sens..

[2]  J. W. F. Goddard,et al.  The ability of dual‐polarization radar (copolar linear) to predict rainfall rate and microwave attenuation , 1984 .

[3]  Venkatramani Balaji,et al.  Remote Sensing of Hail with a Dual Linear Polarization Radar , 1986 .

[4]  Eugenio Gorgucci,et al.  Calibration of radars using polarimetric techniques , 1992, IEEE Trans. Geosci. Remote. Sens..

[5]  Robert A. Black,et al.  The Concept of “Normalized” Distribution to Describe Raindrop Spectra: A Tool for Cloud Physics and Cloud Remote Sensing , 2001 .

[6]  Alexander V. Ryzhkov,et al.  Advantages of Rain Measurements Using Specific Differential Phase , 1996 .

[7]  Eugenio Gorgucci,et al.  Self-consistency of polarization diversity measurement of rainfall , 1996, IEEE Trans. Geosci. Remote. Sens..

[8]  D. Zrnic,et al.  Doppler Radar and Weather Observations , 1984 .

[9]  V. Chandrasekar,et al.  Axis ratios and oscillations of raindrops , 1988 .

[10]  C. Ulbrich.  Natural Variations in the Analytical Form of the Raindrop Size Distribution , 1983 .

[11]  Jothiram Vivekanandan,et al.  Rigorous Approach to Polarimetric Radar Modeling of Hydrometeor Orientation Distributions , 1991 .

[12]  A. R. Jameson.  Microphysical Interpretation of Multi-Parameter Radar Measurements in Rain. Part I: Interpretation of Polarization Measurements and Estimation of Raindrop Shapes. , 1983 .

[13]  T. Oguchi.  Electromagnetic wave propagation and scattering in rain and other hydrometeors , 1983, Proceedings of the IEEE.

[14]  A. R. Jameson,et al.  Estimation of Propagation-Differential Phase Shift from Sequential Orthogonal Linear Polarization Radar Measurements , 1985 .

[15]  J. W. F. Goddard,et al.  Technique for calibration of meteorological radars using differential phase , 1994 .

[16]  V. N. Bringi,et al.  Technology of Polarization Diversity Radars for Meteorology , 1990 .

[17]  A. R. Jameson.  Microphysical Interpretation of Multi-Parameter Radar Measurements in Rain. Part II: Estimation of Raindrop Distribution Parameters by Combined Dual-Wavelength and Polarization Measurements , 1983 .

[18]  Eugenio Gorgucci,et al.  A Robust Estimator of Rainfall Rate Using Differential Reflectivity , 1994 .

[19]  Rodney J. Kubesh,et al.  Laboratory Measurements of Small Raindrop Distortion. Part 2: Oscillation Frequencies and Modes , 1991 .

[20]  P. T. Willis,et al.  Functional fits to some observed drop size distributions and parameterization of rain , 1984 .

[21]  K. Beard,et al.  A New Model for the Equilibrium Shape of Raindrops , 1987 .

[22]  Karen Andsager,et al.  Laboratory Measurements of Axis Ratios for Large Raindrops , 1999 .

[23]  V. Chandrasekar,et al.  An Examination of Propagation Effects in Rainfall on Radar Measurements at Microwave Frequencies , 1990 .

[24]  Lawrence D. Carey,et al.  Radar observations of the kinematic, microphysical, and precipitation characteristics of two MCSs in TRMM LBA , 2002 .

[25]  H. Pruppacher,et al.  A Semi-Empirical Determination of the Shape of Cloud and Rain Drops , 1971 .

[26]  D. Yates,et al.  The Influence of Terrain on Rainfall Estimates from Radar Reflectivity and Specific Propagation Phase Observations , 1999 .

[27]  Guifu Zhang,et al.  Experiments in Rainfall Estimation with a Polarimetric Radar in a Subtropical Environment , 2002 .

[28]  G. Mccormick,et al.  Principles for the radar determination of the polarization properties of precipitation , 1975 .

[29]  Jothiram Vivekanandan,et al.  A Comparison of Radar Reflectivity Estimates of Rainfall from Collocated Radars , 1999 .

[30]  A. W. Green,et al.  An Approximation for the Shapes of Large Raindrops , 1975 .

[31]  Eugenio Gorgucci,et al.  A procedure to calibrate multiparameter weather radar using properties of the rain medium , 1999, IEEE Trans. Geosci. Remote. Sens..

[32]  Guifu Zhang,et al.  A method for estimating rain rate and drop size distribution from polarimetric radar measurements , 2001, IEEE Trans. Geosci. Remote. Sens..

[33]  V. Chandrasekar,et al.  Simulation of Radar Reflectivity and Surface Measurements of Rainfall , 1987 .

[34]  Eugenio Gorgucci,et al.  Specific Differential Phase Estimation in the Presence of Nonuniform Rainfall Medium along the Path , 1999 .

[35]  Ziad S. Haddad,et al.  A new parametrization of the rain drop size distribution , 1997, IEEE Trans. Geosci. Remote. Sens..