Semiempirical law relating cross-polarisation discrimination to fade depth for rainfall

A semiempirical law relating crosspolarisation discrimination (x.p.d.) to attenuation during rainfall is evolved by the comparison of theoretical predictions of x.p.d. (from a constant-canting-angle rainfall model) with 3.5 years of crosspolarisation data at 11 GHz. The concept of an equivalent mean, canting angle is proposed, and it is seen that the use of an equivalent mean canting angle of 4° in the semiempirical law gives an x.p.d. exceeded for 90% of the time. Typical x.p.d. values for deep fades are given by using an equivalent mean canting angle of 2 or 3°.