Estimation of cross polarization of millimeter waves due to rain over few stations in India and its modification incorporating measured values of rain height

In this paper an attempt has been made to compute cross polarization of millimeter waves in the 30-35 GHz frequency range due to rain. Assuming Laws and Parson´s [Laws JO and Parsons DA, 1943] drop size distributions for oblate spheroid drops at 20 /spl deg/C ITU-R method [ITU-R, 1990] has been used to predict depolarization (XPD) for circular polarization. The study includes a number of earth stations in a temperate country like India, namely, Allahabad, Ahmadabad, Bangalore, Calcutta, Delhi, Gangtok, Jodhpur, Madras, Nagpur and Trivandrum. Variations of co-polar attenuation with XPD ha been shown. Cumulative time distribution of XPD has also been presented. The study reveals that cross polarization depends on frequency, path elevation angle, co-polar attenuation and rainfall rate.