NHESS Natural Hazards and Earth System Sciences NHESS Nat. Hazards Earth Syst. Sci. 1684-9981 Copernicus Publications Göttingen, Germany 10.5194/nhess-11-3067-2011 Optimal rain rate estimation algorithm for light and heavy rain using polarimetric measurements Elmzoughi A. 1 Abdelfattah R. 1 2 Santalla Del Rio V. 3 Belhadj Z. 1 URISA, Higher School of Communication of Tunis, University of Carthage, Tunisia Département Image et Traitement de l'Information, Telecom Bretagne, France EE de Telecomunicación, Universidad de Vigo, 36211, Vigo, Spain 21 11 2011 11 11 3067 3079 Copyright: © 2011 A. Elmzoughi et al. 2011 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://nhess.copernicus.org/articles/11/3067/2011/nhess-11-3067-2011.html The full text article is available as a PDF file from https://nhess.copernicus.org/articles/11/3067/2011/nhess-11-3067-2011.pdf

In this paper, we propose an ameliorated physically-based rain rate estimation algorithm for semi-arid regions using the Rayleigh approximation. The proposed algorithm simultaneously uses the reflectivity and the specific differential phase to provide an accurate estimation for both small and large rain rates. In order to validate the proposed estimator, simulated polarimetric rain rate data based on a dual approach, referring to both physical and statistical models of the rain target, are used. Moreover, experimental radar data (the same as used in Matrosov et al., 2006) taken in light to moderate stratiform rainfalls with rain rates varying between 2 and 15 mm h<sup>−1</sup> were collected as part of the GPM pilot experiment. It is shown that the proposed algorithm for rain rate estimation based on the full set of polarimetric radar measurements agree better with in situ disdrometer ones.

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