Dual-Frequency Radar Observations of Precipitation

Abstract

An equal volume, dual-frequency radar system is used to obtain a quantitative characterization of a precipitation volume. The power back-scattered is related to the rainfall rate through the use of an assumed exponential drop-size distribution and the Mie radar cross section. A method is given whereby the relative consistency of a dual-frequency radar system is aided by calibration in the Rayleigh scattering region of a light rainshower. Discrepancies that occur in the observed rainfall rate are attributed to: 1) errors in the form of the assumed drop-size distribution, and 2) local vertical velocity and velocity divergence. Simultaneous observations of precipitation by the dual-frequency radar and raingages are shown for two rain situations.