Estimation of effective path lengths of rain based on cell size distributions from meteorological radar

Abstract

This paper presents a methodology for estimating rain lengths over slant paths derived from volumetric structures of rain cells. The space distribution of rain is obtained from meteorological volumetric radar data. Case studies for stratiform and convective rain distributions are analyzed. Estimation of height and length of rain is discussed for observed events. The spatial and temporal variability with different elevation angles are also analyzed. Finally a version of the implemented algorithm is presented in order to use it in generating time series rain lengths that can lead to a long term statistical study of the rain effective lengths variability for different paths.Index Terms-meteorological radar, rain attenuation, reflectivity.I.

A Survey of Rain Fade Models for Earth–Space Telecommunication Links—Taxonomy, Methods, and Comparative Study

“…If R < R 0 then L H = H R −H s tan θ (km), and if R ≥ R 0 then L H = a(R) (km) (Figure 1), and 'N e f f ' is the effective number of rain cells given by N e f f (θ, R) = n 1 (θ) + n 2 (θ) • R, where n 1 (θ) = 2.38θ −1.45 + 0.82, and n 2 (θ) = −0.01θ 0.52 + 0.09 (θ is elevation angle). [44] The estimation of the rain path can be determined by calibrating the reflected signal Z th in clear-sky conditions and in rainy conditions Z rain . Once rainfall events are identified the first step of the procedure involves the determination of the volume of the rain cell with Z rain > Z th .…”