Analysis of the copolar correlation coefficient between horizontal and vertical polarizations

Abstract

Recent research has suggested that the copolar correlation coefficient termed ρhv(0) can be used to identify large hail and improve polarization estimates of rainfall. The typical measured values of ρhv(0) at S band vary approximately between 0.8 and 1.0. For applications to hail identification, the required accuracy should be within ±0.01, while for rainfall improvement a higher accuracy is necessary, for example, within ±0.001. The statistics of the estimator of ρhv(0) using the Gaussian spectrum approximation from both an analytical approach and using simulations are discussed. The standard deviation and bias in ρhv(0) are computed as a function of number of samples. Doppler spectral width, and mean value of ρhv(0). The effect of finite signal-to-noise ratio and phase noise are also studied using simulations. Several other estimators of ρhv(0) are evaluated. -from Authors