Worst month statistics of attenuation and XPD on earth-space path

The establishment of a reliable space communication system operating at frequencies above 10 GHz must be based on detailed knowledge of attenuation and cross-polarization discrimination (XPD) characteristics along earth-space path in these frequency bands. In some cases, the attenuation and XPD statistics of the worst month is needed. This paper provides a description of the worst month statistics of attenuation and and XPD regarding an earth-space path at 11.7 GHz (vertical polarization with a tilt angle of about 5 deg) and 19.5 GHz (circular polarization). It is found that the probability relation between the annual and worst month statistics is approximated by the power-law relation. The relations are independent of frequency and polarization.