Retrieval of Atmospheric Parameters from Hydrometeor Backscatter Measured with Doppler Radar Profiler

Abstract

The evaluation of backscatter spectra of clouds and precipitation measured with Doppler radar profilers allows the retrieval of a number of important atmospheric parameters. This retrieval leads to inaccurate results if vertical wind parameters are not taken into account. An algorithm allowing the correction of these errors by solely using profiler spectra is introduced. The algorithm allows the retrieval of vertical wind parameters by fitting a special function to a part of the backscatter spectra. This function is derived and a sensitivity analysis on input parameters for the retrieved values is performed. Further processing of the spectra to calculate drop size distribution, liquid water content, and rain rate is described. Performance and restrictions of the retrieval algorithm are demonstrated by means of measurements taken with a unique 94-GHz frequency modulated?continuous wave Doppler radar profiler and collocated 915-MHz and 2.8-GHz profilers. The results are discussed, and operational strategies are pointed out. A summary and outlook to further developments conclude this report.