Attenuation Calibration of an X-Band Weather Radar Using a Microwave Link

Abstract The attenuation of a radar signal is a serious problem facing meteorologists and hydrologists. In heavy rain, reflectivity information can be completely lost from large portions of a radar scan. The problem is particularly acute for X-band radars. Current methods of correcting for attenuation face many difficulties, mainly because the actual amount of attenuation at any given time is unknown. In this paper a backward-iterative attenuation-correction algorithm is presented that uses the attenuation measured by a microwave link with its receiver collocated with an X-band weather radar in Essen, Germany. Data are also available from a network of rain gauges located in the vicinity of the link path. This network provides a measure of “ground truth” rainfall against which radar estimates can be compared. The results show that the algorithm can recover much of the reflectivity information that is lost due to attenuation of the radar beam. The method is seen to be particularly effective in convective co...

[1]  Graham J. G. Upton,et al.  Use of dual-frequency microwave links for measuring path-averaged rainfall , 2003 .

[2]  M. Gosset.  Effect of Nonuniform Beam Filling on the Propagation of Radar Signals at X-Band Frequencies. Part II: Examination of Differential Phase Shift , 2004 .

[3]  Guy Delrieu,et al.  Feasibility of Using Mountain Return for the Correction of Ground-Based X-Band Weather Radar Data , 1997 .

[4]  Jacques Testud,et al.  The Rain Profiling Algorithm Applied to Polarimetric Weather Radar , 2000 .

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

[6]  Hans-Reinhard Verworn,et al.  Improvement of X-band radar rainfall estimates using a microwave link , 2005 .

[7]  M. Cross,et al.  Scattering of a plane electromagnetic wave by axisymmetric raindrops , 1974 .

[8]  Sergey Y. Matrosov,et al.  X-Band Polarimetric Radar Measurements of Rainfall , 2002 .

[9]  Graham J. G. Upton,et al.  On-line detection of errors in tipping-bucket raingauges , 2003 .

[10]  Walter Hitschfeld,et al.  ERRORS INHERENT IN THE RADAR MEASUREMENT OF RAINFALL AT ATTENUATING WAVELENGTHS , 1954 .

[11]  A. R. Rahimi,et al.  Comparison of the use of dual-frequency and single-frequency attenuation for the measurement of path-averaged rainfall along a microwave link , 2003 .

[12]  Mongi Marzoug,et al.  A Class of Single- and Dual-Frequency Algorithms for Rain-Rate Profiling from a Spaceborne Radar. Pad I: Principle and Tests from Numerical Simulations , 1994 .

[13]  Graham J. G. Upton,et al.  Dual-frequency links—a complement to gauges and radar for the measurement of rain , 2004 .

[14]  Louis J. Battan,et al.  Radar Observation of the Atmosphere , 1973 .

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

[16]  Sergey Y. Matrosov,et al.  Prospects for Measuring Rainfall Using Propagation Differential Phase in X- and Ka-Radar Bands , 1999 .

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

[18]  I. Zawadzki,et al.  Effect of Nonuniform Beam Filling on the Propagation of the Radar Signal at X-Band Frequencies. Part I: Changes in the k(Z) Relationship , 2001 .

[19]  Graham J. G. Upton,et al.  Microwave links: The future for urban rainfall measurement? , 2005 .

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