INTERCOMPARISON OF TECHNIQUES TO CORRECT FOR ATTENUATION OF C-BAND WEATHER RADAR SIGNALS

Quantitative application of radar measurements at C band requires corr ection for attenuation. Algorithms to correct for attenuation and diff erential attenuation are evaluated based on theoretical analysis as we ll as radar data. The error structure of three different attenuation c orrection algorithms based on (a) reflectivity, (b) reflectivity and d ifferential reflectivity, and (c) specific differential propagation ph ase is analyzed. The error structure of two algorithms to correct the differential attenuation based on (a) reflectivity and differential re flectivity, and (b) specific differential propagation phase is present ed. Data from the polarimetric C-band Doppler radar POLDIRAD operated by DLR (Germany) are utilized to intercompare the attenuation and diff erential attenuation correction algorithms. Radar data and theoretical analysis show that the attenuation correction algorithm using reflect ivity and differential reflectivity agrees well with the attenuation c orrection algorithm based on specific differential phase. Similarly, r adar data and theoretical analysis indicate that the algorithms to cor rect for differential attenuation compare well with each other. In add ition the fractional standard error of comparison between the algorith ms to correct for attenuation and differential attenuation is in good agreement with theoretical results, providing an indirect verification of the accuracies of the algorithms.