Open AccessEstimation of Depolarization Ratio Using Weather Radars with Simultaneous Transmission/Reception
Author(s) -
Alexander V. Ryzhkov,
Sergey Y. Matrosov,
Valery Melnikov,
Dušan S. Zrnić,
Pengfei Zhang,
Qing Cao,
Michael Knight,
Clemens Simmer,
Silke Troemel
Publication year - 2017
Publication title -
journal of applied meteorology and climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.079
H-Index - 134
eISSN - 1558-8432
pISSN - 1558-8424
DOI - 10.1175/jamc-d-16-0098.1
Subject(s) - differential phase , radar , weather radar , polarimetry , polarization (electrochemistry) , depolarization ratio , optics , remote sensing , axial ratio , physics , phase (matter) , circular polarization , geology , telecommunications , computer science , scattering , microstrip , chemistry , quantum mechanics
A new methodology for estimating the depolarization ratio (DR) by dual-polarization radars with simultaneous transmission/reception of orthogonally polarized waves together with traditionally measured differential reflectivity Z DR , correlation coefficient ρ hυ , and differential phase Φ DP in a single mode of operation is suggested. This depolarization ratio can serve as a proxy for circular depolarization ratio measured by radars with circular polarization. The suggested methodology implies the use of a high-power phase shifter to control the system differential phase on transmission and a special signal processing to eliminate the detrimental impact of differential phase on the estimate of DR. The feasibility of the suggested approach has been demonstrated by retrieving DR from the standard polarimetric variables and the raw in-phase I and quadrature Q components of radar signals and by implementing the scheme on a C-band radar with simultaneous transmission/reception of horizontally and vertically polarized waves. Possible practical implications of using DR include the detection of hail and the determination of its size above the melting layer, the discrimination between various habits of ice aloft, and the possible identification and quantification of riming, which is associated with the presence of supercooled cloud water. Some examples of these applications are presented.