Study of Turbulence in Clouds by Double-Frequency Radar

Abstract

Radar measurements of rain intensity are of great practical importance and usually based on radar reflectivity. But this characteristic depends on type of precipitations, season, latitude etc. and that is why it is reasonable to use additional characteristics of precipitations (clouds) that may be connected with fluctuations of the radar signals scattered from meteorological objects. In this report the design and parameters of the double band radar for study of fluctuations of signals scattered by precipitations and clouds are presented. It was showed that spectrum width contains Gauss dependence in energetic area of the spectrum (>−16 dB) and power dependence in periphery of the spectrum (<−20 dB). Gaussian component is determined by slow displacements of comparatively large volumes (irregularities of density of rain particles) and the power component is due to fast displacements of rain particles (vibrations of drops, reciprocal shading of the drops etc). Spectrum width is proportional to a rain intensity that may be useful for measurement of rain intensity.