Print Email Facebook Twitter High-Resolution Raindrop Size Distribution Retrieval Based on the Doppler Spectrum in the Case of Slant Profiling Radar Title High-Resolution Raindrop Size Distribution Retrieval Based on the Doppler Spectrum in the Case of Slant Profiling Radar Author Unal, C.M.H. Faculty Civil Engineering and Geosciences Department Geoscience and Remote Sensing Date 2015-06-17 Abstract Doppler spectra from vertically profiling radars are usually considered to retrieve the raindrop size distribution (DSD). However, to exploit both fall velocity spectrum and polarimetric measurements, Doppler spectra acquired in slant profiling mode should be explored. Rain DSD samples are obtained from simultaneously measured vertical and slant profile Doppler spectra and evaluated. In particular, the effect of the horizontal wind and the averaging time are investigated. The Doppler spectrum provides a way to retrieve the DSD, the radial wind, and a spectral broadening factor by means of a nonlinear optimization technique. For slant profiling of light rain when the horizontal wind is strong, the DSD results can be affected. Such an effect is demonstrated on a study case of stratiform light rain. Adding a wind profiler mode to the radar simultaneously supplies the horizontal wind and Doppler spectra. Before the retrieval procedure, the Doppler spectra are shifted in velocity to remove the mean horizontal wind contribution. The DSD results are considerably improved. Generally, averaged Doppler spectra are input into this type of algorithm. Instead, high-resolution, low-averaged Doppler spectra are chosen in order to take into account the small-scale variability of the rainfall. Investigating the linear relations at fixed median volume diameter, measured reflectivity-retrieved rainfall rate, for a slant beam, the consistency of the integrated parameters is established for two averaging periods. Nevertheless, the corresponding DSD parameter distributions reveal differences attributed to the averaging of the Doppler spectra. The new aspects are to obtain the same retrieval quality as vertically profiling and highly averaged spectra in an automated way. Subject rainfalldrop size distributionalgorithmsprofilers, atmosphericradars/radar observations To reference this document use: http://resolver.tudelft.nl/uuid:ffae8b74-7465-4f87-8df5-e5da8a75fb23 Publisher American Meteorological Society Embargo date 2016-01-17 ISSN 0739-0572 Source https://doi.org/10.1175/JTECH-D-13-00225.1 Source Journal of Atmospheric and Oceanic Technology, 32, 2015 Part of collection Institutional Repository Document type journal article Rights (c) 2015 American Meteorological Society Files PDF Unal.pdf 3.29 MB Close viewer /islandora/object/uuid:ffae8b74-7465-4f87-8df5-e5da8a75fb23/datastream/OBJ/view