A stochastic model of range profiles of raindrop size distributions: Application to radar attenuation correction

To analyze the influence of the spatial variability of the raindrop size distribution (DSD) on rainfall estimation using weather radar, a stochastic model is proposed in order to simulate range profiles of DSDs and consequently profiles of rainfall intensity, radar reflectivity and specific attenuation. A first application concerning the accuracy of attenuation correction algorithms is presented. Using a Monte Carlo technique, it is shown that an attenuation correction algorithm based on a forward implementation is more sensitive to the inadequacy of power-law relations than a backward algorithm, the latter being sensitive to the uncertainty of the path integrated attenuation (PIA). The sensitivity to spatial heterogeneity is limited for both algorithms. The corrected profiles remain uncertain because they are based on deterministic power-law relations which are not fully consistent with the stochastic nature of the DSD.